Società italiana di EEG e neurofisiologica clinica, Annual Spring Meeting

Società italiana di EEG e neurofisiologica clinica, Annual Spring Meeting

Electroencephalography and clinical Neurophysiology, 1986, 63: 47P-72P 47P Elsevier Scientific Publishers Ireland, Ltd. Society proceedings SOCIETA...

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Electroencephalography and clinical Neurophysiology, 1986, 63: 47P-72P

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Elsevier Scientific Publishers Ireland, Ltd.

Society proceedings SOCIETA ITALIANA DI EEG E NEUROFISIOLOGICA CLINICA, ANNUAL SPRING MEETING Lipari, June 2-4, 1984

Secretary: Prof. GIUSEPPE C A R U S O Cattedra di Neurofisiopatologia, Second School of Medicine, University of Naples, Via Pansini 5, 80131 Naples (ltalv) (Received for publication: August 23, 1985)

1. Effect of phosphatidylserine on EEG and behavioural changes in the aging rat. - - A. Zanotti, F. Aporti, R. Rubini and G. Toffano (Abano Terme) Seizure-like EEG patterns occur spontaneously in rats from about the age of 11 months. The number of animals presenting these seizures increases with age, reaching about 90% at 2 years. The amplitude of these waves is 3 - 8 times larger than normal EEG activity and their mean frequency ranges from 6.8 to 9.4 Hz. The frequency was peculiar to each animal and it underwent no changes throughout the 3 m o n t h observation period. These waves appear in bursts, lasting from 1 to above 60 sec, in both hemispheres symmetrically and synchronously and present a marked monophasicity. They occur only when the animals are immobile and are interrupted by acoustic stimulation. Affected rats also show behavioural changes. With aging there are changes in the protein, cholesterol and phospholipid content of cerebral membranes, and a decrease of N a + / K +-ATPase activity. These changes are counteracted by the natural phospholipid, phosphatidylserine (BC-PS). Chronic administration of BC-PS reduces both the number and the total duration of seizure-like bursts and improves behavioural performances. These data suggest a possible role of BC-PS as a pharmacological agent for the aging brain and a possible correlation between EEG, behaviour and N a + / K + - A T P a s e . 2. lntraindividual variability of cardiovascular autonomic tests in diabetics. - - G. Comi, M.F. Ghilardi, L. Lozza, T. Locatelli, A. Poggi and G. Galardi (Milan) The aim of the present study was to evaluate the reproducibility of 5 tests that explore orthosympathetic and parasympathetic functions in diabetics. Ten insulin-dependent diabetics (7 males and 3 females) with age range from 19 to 49 years, mean age 32.9 years, were examined 5 times on 5 different days by the same investigator and in the same basal conditions. The patients underwent the following tests each day: heart rate variation on deep breathing, Valsalva manoeuvre, lying to standing, blood pressure response to standing, and sustained handgrip. Reproducibility was evaluated by the Fisher correlation coefficient (r). The most reproducible tests were deep breathing ( r = 0.99), orthostatic hypotension ( r = 0 . 9 8 ) and Valsalva manoeuvre (r = 0.97). The handgrip and lying to

standing tests were more variable and less reproducible than the other tests, having r = 0.92 and r = 0.79, respectively. 3. The brain distribution of phenobarbital and carbamazepine given in combination in experimental epilepsy. - - F. Monaco, G.P. Sechi, A. Russo, S. Traccis and R. Mutani (Turin and Sassari) This study describes the distribution in the brain of phenobarbital (PB) and carbamazepine (CBZ) given in combination to normal cats, and to cats rendered epileptic by parenteral penicillin and by penicillin topically applied on the neocortex. The two drugs were extremely low in controls, and relatively high in epileptic cats. CBZ showed the greatest increase. This m a y be partly due to the ability of CBZ to prevent the metabolic alterations associated with severe convulsions and hence the binding impairment. As this event did not potentiate the CBZ anticonvulsant activity, there is no sound experimental evidence that two drugs are better than one in controlling epilepsy. 4. Experimental study of the evolution of status epilepticus during cerebral maturation. - - M.R. De Feo, O. Mecarelli, L. Germani and G.F. Ricci (Rome) The evolution of status epilepticus, induced by parenteral administration of pentylenetetrazol (PTZ), has been studied in developing rats. Usually no correlations were found between behavioural modifications and epileptic EEG activity during the first days of life. Tonic seizures with EEG desynchronization were the most typical electro-clinical pattern at this age. During the second week the first myoclonic jerks, with and without diffuse bursts of polyspikes, appeared. They became more massive and organized during the third week when also clonic seizures, sometimes preceded by a short tonic phase, were observed. At this age it was possible to obtain a myoclonic status epilepticus. From the fourth week on, the behavioural and electrical pattern was very similar to that of the adult animal. The different electro-clinical patterns obtained at the various ages are discussed in relation to the maturation of the various cerebral regions.

0013-4649/86/$03.50 © 1986 Elsevier Scientific Publishers Ireland, Ltd.

48P 5. Cervical and lumbar vestibulo-spinal influences in relation to caloric stimulation of the labyrinth and to different body tilts in man. - - A. Rossi, B. Rossi and G. Cei (Siena and Pisa)

The effect induced by caloric stimulation can be divided into an exteroceptive phase and a proprio-vestibular phase. The former has a bilateral facilitatory effect on the 4 limbs, which ceases with interruption of the stimulus. During the propriovestibular phase of nystagmus, the cervical motoneurons, studied by the H reflex from the upper limb, showed ipsilateral facilitation and contralateral inhibition in 10 normal subjects. Changes in excitability of the alpha motoneurons of the soleus muscles were modest a n d bilaterally facilitatory. From the different responses observed in the upper and lower limbs we suggest the activation of different vestibulo-spinal pathways able to mediate the effects of ampullary stimulation. The H reflex of antigravity muscles of the upper and lower limbs shows a significant facilitation when the body is rotated from a horizontal position towards vertical, and a significant decrease when the body is returned to the original position. In conclusion, the h u m a n otolithic system responds to gravity in relation to different static positions of the body by producing responses from antigravity limb motoneurons. Finally, also the ampullary system seems to control the excitability of the limb alpha motoneurons, although the significance of this control is not clear. 6. Early bracing in the treatment of spinal muscular atrophy (SMA) to promote standing and ambulation. - - C. Granata, L. Merlini, S. Bonfiglioli and P. Mattutini (Bologna)

Children with the intermediate form of SMA cannot stand or walk. At an early age these children develop deformities of the spine and lower limbs as a result of their sitting position. When these children are between the ages of 12 and 18 months, long leg braces with ischial supports are applied in order to allow them to stand up. In almost all cases a standing position is achieved, and in some case unassisted walking is also achieved. Data on 10 cases are reported and the braces -are described.

7. Microinjections of kainic acid into the entorhinal cortex: electrographic changes in developing rats. - - O. Mecarelli, M.R. De Feo, L. Giustolisi and G.F. Ricci (Rome)

Microinjections of kainic acid (KA) into the entorhinal cortex of 8-11-day-old rats induce the appearance of a local epileptic response, which rapidly diffuses to the hippocampus. In some animals a primary hippocampal activation has also been observed in the absence of any epileptic entorhinal activity. In older animals epileptic discharges always arise at the injection site with a shorter latency and a more typical morphology than in younger rats. These discharges rapidly spread to the other cerebral structures and evolve into status epileptiCUS.

SOCIETY P R O C E E D I N G S The results demonstrate that the kainate a n d / o r glutamate receptors and the excitatory pathways that connect the entorhinal cortex and the hippocampus are usually already mature from the second week of life. The primary hippocampal activation may be explained by the hypothesis that, in this case, the entorhinal cortex is not yet sufficiently mature to organize its own response while it is sufficiently excitable to activate the glutameric pathway and, subsequently, the hippocampus.

8. Functional evaluation scale in cases of spinal muscular atrophy (SMA). - - L. Merlini, C. Granata, S. Bonfiglioli and P. Maltutini (Bologna)

A functional evaluation scale in non-walking patients with SMA has been devised. Functional evaluation scales for I)uchenne's muscular dystrophy do not adequately define functional ability in cases of SMA because they are not sufficiently differentiated for patients confined to a wheelchair. Our scale quantifies the changes that occur in functional abilities with age, with the development of scoliosis and after surgical treatment. The scale can be applied to point 9 or 10 on Vignos' functional scale, and takes into consideration the ability to roll, to sit, to sit unassisted, to lift hand above the head, to raise the hand to the mouth. The maximum score is 10. This system was ~ried on 9 patients and proved to be reliable in defining functional capacity. 9. Behavioural and electroencephalographic study of systemic kainic acid-induced epilepsy in the rat. - - M. Onofrj, M. Scerrati, P. Pola, G.F. Rossi, L. Pacifici and M.T. Ramacci (Rome)

A systemic study of the epileptic electrocerebral and behavioural effects of intraperitoneal kainic acid (KA) has been performed in 92 adult albino Wistar rats. The doses of KA ranged from 3 to 20 m g / k g . Chronic epidural and stereotaxically implanted cerebral electrodes (hippocampus, amygdala and thalamic reuniens nucleus) were used. All animals were studied for 5-12 h after KA injection. Twenty of the animals were studied for 10 days. Sporadic spiking was the first EEG manifestation of epilepsy. Subsequently, ictal discharges were recorded. Both types of epileptic discharges were at first focal, and then generalized. In the majority of animals both electrographic events were first recorded from the limbic structures; in 7-35% of cases, however (depending on the dose of KA), they first appeared in the neocortex. Two groups of behavioural manifestations were observed: (1) searching, staring spells, wet dog shaking and gnawing: they were independent of the EEG epileptic ictal activity; (2) rearing: it was always related to ictal limbic generalized discharges; head nodding, forelimb clonus and tonic-clonic spells: always related to ictal generalized EEG seizures. Spiking was still recorded from different structures I0 days after the KA injection.

I T A L I A N EEG SOCIETY, A N N U A L S P R I N G M E E T I N G

10. Modifications of brain-stem auditory evoked potentials and electroencephalogram during hypoxia in the rabbit. - - F. Pierelli, G.L. Mattioli, G. Soldati, R. Rocco, G. Santarcangeio and P.A. Rizzo (Rome) To study the effect of hypoxia on brain activity we recorded brain-stem auditory evoked potentials (BAEPs) in 10 rabbits while they were breathing a gas mixture containing 5% 02. Arterial blood gas levels, pH, arterial blood pressure, EEG and body temperature were monitored. EEG alterations appeared before any significant variation of BAEPs. When the EEG became isoelectric, brain-stem responses were still recordable, albeit with reduced voltages and increased interpeak latencies. BAEP alterations were found also before any arterial blood pressure depression. This could indicate that BAEP records reveal brain-stem abnormalities in the early stages of induced hypoxia as a direct effect of this condition independent of circulatory influence. A correlation ( P < 0.001) was found between the degree of blood acidosis and the increase in central conduction time ( I - I V interpeak latency).

11. Effects of apomorphine on smooth pursuit eye movements in Huntington's disease. - - L.M. Specchio, M. De Tommaso, G. Olivieri, A. La Neve and F.M. Puca (Bari) Impairments of smooth pursuit eye movements (SPEM) in extrapyramidal disorders are described. To evaluate the interference of the dopaminergic pathways on the SPEM system 20 ~ g / k g of apomorphine were administered subcutaneously to patients with Huntington's disease (HD). SPEMs were elicited by a pendular horizontally moving luminous spot on a screen at 1 m distance from the patient, with a frequency of 0.4 Hz. SPEM recording was performed in basic conditions and every 15 min after apomorphine administration for at least 90 min. The intensity of choreic movements was evaluated before and during the test. H D SPEMs appeared for erratic a n d / o r saccadic corrective movements. With apomorphine the instrumental records deteriorated, while there was a clinical improvement (reduction of choreic movements).

12. A quantitative analysis of the beat-to-beat test in autonomic neuropathy. - - V. Tugnoli, M.C. Cristofori, G. Serra, M. Manca, M. Bottoni and R. Eleopra (Ferrara) A linear regression slope was obtained by correlating the variation of respiratory arrhythmia and the breath intensity determined by chest diameter variations in 22 normal subjects and in 12 patients suffering from insulin-treated diabetes mellitus. In these patients no autonomic clinical or neurophysiological dysfunctions were detected by the standard tests. However, five of these patients presented an abnormal regression slope. The findings suggest that an inadequate respiratory arrhythmia in relation to different breathing depths could precede other signs of autonomic neuropathy.

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13. Alzheimer's disease neurophysiological data: a multimodal investigation. - - C. Bianco, P. Benna, P. Costa, L. Tarenzi, D. Leotta, L. Scarzella, 1. Rainero, L. Pinessi and B. Bergamasco (Turin) EEG, brain-stem auditory evoked potentials (BAEPs), pattern reversal visual evoked potentials (PEVs) and somatosensory evoked potentials (PESs) to stimulation of the median nerve at the wrist have been recorded in 14 subjects suffering from Alzheimer-type senile dementia, in order to evaluate the cortical-subcortical conduction, and to analyse superior associative functions. BAEPs were altered in 71.4% of the patients (there was a high acoustic threshold in 21.4%). The alterations were bilateral in 42.8% of the cases, and unilateral in 28.6%. Alterations involved both the morphology and the interpeak latency intervals. PEVs were normal in 28.6%, irregular but with latencies within normal limits in 50%, recordable but altered in 7.3%, non-recordable in 14%. Normal PESs were recorded from Erb's point in all the patients. In 33% of the cases there were alterations of the spinal response, whereas 41.7% presented alterations of the cortical response. Central conduction time (N13-N20) was normal in 66.7% of the patients.

14. Electrophysiological study in patients affected by chronic respiratory insufficiency: preliminary results. - - M. Boat/a, G. Pozzessere, E. Stefano, E. Valle, F. Giramma and C. Morocutti (Rome) Symptoms and signs of respiratory encephalopathy in chronic respiratory insufficiency (CRI) appear when hypoxemia and hypercapnia rise to high levels. Ten patients aged from 49 to 65 years~ affected by CRI for at least 5 years, were studied to verify if low but prolonged hypoxemia and hypercapnia levels alter cerebral metabolism. No patient developed respiratory encephalopathy. After an ophthalmic (ocular fundus, perimetry, vision) and audiometric examination, patients were studied by means of pattern reversal visual evoked potentials (VEPs), brain-stem auditory evoked potentials (BAEPs) and EEG. An arterial blood sample was taken immediately after to study pH, pO 2 and pCO 2. Four patients showed pathological VEP latencies; one had EEG alterations. Only patients with a long history of CRI presented EP anomalies. These preliminary findings suggest that in forms of CRI without neurological impairment a minimal neurofunctional alteration may be revealed by means of evoked potentials. The high percentage of VEP anomalies can be due to a particular sensitivity of the visual pathway to hypoxic-hypercapnic damage.

15. Long latency negative potentials during a motor-perceptual task. Developmental aspects in normal children. - - G.A. Chiarenza, M.B. Tengattini, A.G. Grioni, D. Ganguzza, G. Vasile, A. Massenti, A. AIbizzati, D. Papakostopoulos and A. Guareschi Cazzullo (Milan, and Bristol, U.K.) The aim of this pilot study was to evaluate both the maturation and distribution on the scalp of post-action negativ-

50P ity (PAN), which was previously found with a latency of about 600 msec after a motor-perceptual task in children aged 8-13 years. We performed a similar investigation in children aged 6 7 years, increasing the number of recording sites. EOG excluded that PAN could be generated by ocular activity recorded at Fpz. In some subjects PAN could be recorded in frontal regions with a greater amplitude at Fz than at Fpz or Cz, while in others the same potential was absent and, in the same latency range, a positive potential, skilled performance positivity (SPP), could be recorded, with a m a x i m u m amplitude in centralparietal regions (Cz, Pz, 174, P3). The finding that PAN is not constantly present in all subjects and that SPP can be recorded in central-parietal regions whenever PAN is absent in frontal regions, suggests that either different maturative levels are related to the two potentials or that children use different strategies to perform motor-perceptual tasks. 16. Pattern reversal visual evoked potentials in young insulindependent diabetics. - - G. Comi, V. Martinelli, M.F. Ghilardi, M.L. Merenda, S. Medaglini and G. Galardi (Milan) Diabetic optic neuropathy is considered very rare: visual loss in diabetes is usually attributed to retinopathy. We studied by checkerboard pattern reversal stimulation 46 diabetic teenagers (mean age 15.2 years, range 10-20 years) without ocular diseases and with normal visual acuity. The check sizes were 11 m m and 5.2 m m subtending respectively an angle of 30' and 15' at the retina. The results were compared with a group of 30 normal subjects matched for age and sex. P100 latency was significantly increased in diabeti~zs at both check sizes. Thirteen diabetics (28.2%) showed an abnormal latency with the 15' pattern, and 7 diabetics (15.2%) had an abnormal latency with the 30' pattern. There was no correlation between the conduction in the optic nerve and in the peripheral sensory and motor fibers. A significant correlation was found between increased P100 latency and the diabetes duration ( P < 0.01). The VEP delay in our diabetics suggests a subclinical optic neuritis. Increased synaptic delay at retinal, geniculate and cortical levels can contribute to VEP alterations. 17. Comparative analysis of cervical SEPs from median, radial and ulnar nerve stimulation. - - F. D'Alpa, G. Sallemi, L. Triffiletti and A. Grasso (Catania) The PI3-P14 and N18 components of the cervical responses from median (MN), ulnar (UN) and radial (RN) nerves show approximately the same morphology (but different amplitudes), whereas P11 shows a different morphology. From UN and RN, PI1 is clearly bilobed ( P l l a + P l l b ) from both C~-Cv2 and C~-Cvv recording sites, while from MN, P l l b is sometimes difficult to recognize from C~-Cv7, and P l l a is difficult to recognize from C~-Cv2. The longer PI 1..... cP13,,,,~ t conduction time for UN with respect to both RN and MN correlates well with the longer spinal pathway. Scalp recorded P13 clearly has

SOCIETY P R O C E E D I N G S a supraspinal origin. The Pl3,,,~t-N18peak intervals of all nerves were superimposable, which is in accordance with the common central pathway.

18. Brain-stem auditory evoked potentials in coma after ~ v e r e head injury: relationship with EEG and outcome. - - P. David, G. Russo and M.F. Laureati (Rome) Brain-stem auditory evoked potentials (BAERs) and EEG were recorded in 30 head injured comatose patients. Their average age was 22 years and the mean post-admission Glasgow Coma Scale (GCS) score was 6.5. The outcome was evaluated with the Glasgow Outcome Scale (GOS) with a mean foUow-up of 6 months. There was a significant correlation between GCS and GOS ( P < 0.01). All patients presenting a normal or slightly altered BAEP had a good evolution except one, despite a low GCS. The remaining patients who presented a low GCS score and severe BAEP alterations (BAEPs were absent in only 1 case) had an unfavourable outcome. The correlation with EEG in patients with monophasic and borderline EEG associated with severe BAEP alterations and in a patient who presented diphasic EEG and mild BAEP alterations resulted in an unfavourable outcome. All patients with EEG traces tending to be isoelectric (evidence of sporadic theta or delta rhythm) had severe BAEP alterations and unfavourable outcomes. Patients with sleep-like, borderline, monophasic and diphasic EEGs associated with normal or mildly altered BAEPs had a favourable outcome. 19. Equipotential line dynamics of CNV. - - F. Denoth, R. Zappoli, I. Brunt, C. Navona and C. Neneioni (Pisa and Florence) A map representation of multi-channel surface recorded CNV activity in man (19 electrodes - - 10/20 system) was obtained by drawing equipotential lines. The spatio-temporal evolution of the averaged electrical activity was represented visually by using either grey or coloured scales. The preliminary results provide evidence that a widespread post-warning negativity, starting about 430 msec around Cz, is present throughout 1SI and justifies the term 'the CNV.' The bilaterally activated, widespread and persistent, post-S1 negativity is sensory modality independent and probably represents the result of a common cortical input controlled by multineuronal, diffuse projection systems. Several other, more variable, negative-positive components, differently overlapping in time and space, appear superimposed on the modality non-specific negativity. The complex and non-homogeneous spatio-temporal topography of these probably more specific components seems to depend essentially on the anatomical/functional characteristics of the cortical areas from which they are recorded. Their polarity and relative distribution may change with different experimental conditions and recording methods. The method adopted seems to provide additional information on the neuronal mechanisms underlying the generation of different ERP components.

ITALIAN EEG SOCIETY, A N N U A L S P R I N G M E E T I N G

20. Brain-stem acoustic evoked potentials (BAEPs) and somatosensory evoked potentials (SEPs) in patients with myotonic dystrophy. - - L. Domenici, B. Rossi, G. Siciliano and L. Murri (Pisa) BAEPs and SEPs have been recorded in 12 patients with myotonic dystrophy to detect possible alterations of the central nervous system. BAEPs from Cz referred to A 1 or A 2, evoked by clicks of alternate polarity, duration 0.1 msec, frequency 10 Hz and intensity 60 dB above acoustic threshold, were averaged. The I-V, I-II, II-III, III-V interpeak conduction times were examined. The latencies of components N9, N12 , N14 , PI5 and N20 and the Nln-N20 conduction time were evaluated. BAEPs were abnormal in 5 patients, of which two also showed anomalies of the central components of SEPs. These alterations were not related to either the length or the severity of the illness.

21. Spinal somatosensory evoked potentials during surgery for scoliosis. - - L. Pelosi, G. Caruso, G. Russo, L. MUano and G. Paolino (Naples) In 12 neurologically normal patients (age range 12-28 years), spinal cord afferent pathway function was monitored during corrective surgery for scoliosis. Spinal responses to tibial nerve stimulation at the popliteal fossa were bipolarly recorded via needle electrodes implanted into flavum ligaments. In preoperative records, besides latency variations, potentials varied greatly in amplitude and shape depending on the recording level. Over the cauda equina the response consisted of a triphasic potential similar to those recorded along peripheral nerves. A long duration, high amplitude negative potential was obtained at the lower thoracic level, and a small polyphasic complex appeared in all recordings performed over the mid and rostral thoracic spines. After the operation, transitory marked amplitude reduction was observed in 10 patients. However, changes constantly affected the large negative-positive component recorded at the thoracic level, and never the potentials obtained over the cauda equina. Results are in agreement with observations made by others in animals and may reflect a different sensitivity to asphyxia of the pre- and postsynaptic spinal cord activity.

22. Short latency somatosensory evoked potentials in peroneal muscular atrophy (PMA): study of a family with an intermediate form. - - A. Rossi, P. dell'Anna, M. Mondelli and C. Paradiso (Siena) Nine patients with an intermediate form of PMA, all from the same family, presented with a significant increase of the interpeak N9-N13 latency. This increase was already present in the presymptomatic phase of the disease and there was no significant difference between patients of different ages and clinical severity, indicating that the lesion appears very early and tends to establish itself equally early. Similar behaviour is also seen in the distal conduction velocity along the sensory

51P fibres, while the proximal areas seem to be relatively spared, as often reported in PMA. These findings are interpreted as an expression of a distal central peripheral sensory neuropathy. The lesion of the peripheral motor fibres, particularly in the legs, had a different and more severe pattern of evolution. Alterations in central conduction time (N13-N20) were not seen in any of the patients studied, indicating that the central sensory lesion does not go beyond the first synapse in the cuneate nucleus.

23. Visual and somatosensory evoked potentials in Huntington's chorea. - - L.M. Specchio, G. Olivieri, L. Margari, M. De Tommaso, M. Bellizzi, M.G. Russo, E. De Liso, M.A. Erriquez, C. Lamorgese, G.M.R. Musmeci, A. La Neve and F.M. Puea (Bad) The patterns of somatosensory evoked potentials (SEPs) and visual evoked potentials (VEPs) were compared with the results of computerized tomography in 7 patients with Huntington's disease (HD). The intensity of choreic movements was scored with a rating scale. Mental deficit was evaluated with WAIS and Bender's test. Stimulating and recording procedures of SEPs were according to standard recommendations of the Italian Society of EEG and Neurophysiology. N9 (Erb's point), N13 (Cv7), P14-N20 (C'3, C'4) were obtained by stimulation of the median nerve at the wrist. VEPs were obtained by stimulating with checkerboard pattern reversal at 1.6 Hz, 100% contrast, 1.9 lg c d / m 2 mean luminance, 4 2 - 2 1 - 1 1 - 5 . 2 m m check sizes. P100 latency and voltage were measured. SEP latencies of recognizable waves were normal. P14-N20 were unrecognizable on both hemispheres in 2 cases, and asymmetric in 4 cases. N20 was enlarged in 1 patient. Regarding VEPs, P100 showed a reduced amplitude and an increased latency. No correlations were found among SEP and VEP anomalies and CT and clinical features.

24. Multimodally evoked potentials in heroin addicts. - - C. Bianco, D. Cocito, P. Costa and P. Benna (Turin) We have recorded EEG, brain-stem auditory evoked potentials (BAEPs) and pattern reversal visual evoked potentials (PEVs) in 9 heroin addicts who inhaled the drug heated on tinfoil ('chinesing'). This method of drug taking has been thought to be responsible for a severe and often lethal encephalopathy. Our patients presented only subjective symptoms and did not show any neurological signs. The results were compared with those obtained in 9 endovenous heroin addicts and with those obtained in normal subjects. No significant variations of EEG or PEVs were found between the 3 groups. BAEPs, on the contrary, showed a greater increase ( P < 0.01) of the interpeak latency intervals between waves V-Ill and V-I in the group of practicing 'chinesing' addicts than in the normal subjects and the endovenous heroin addicts.

52P 25. Brain-stem acoustic evoked potentials in 164 patients examined within 48 h of a minor head injury. - - P. Bortolotti, M. Gentilini, P. Malavasi, G.A. Medi, R. Schoenhuber and L. Tonelli (Modena) BAEPs were recorded within 48 h of a minor head injury in 165 patients, 108 males and 57 females, with a mean age of 29 years (range 12-77 years). Considering interpeak latencies I-III, III-V and I-V, 17 (10%) had altered BAEPs. One interpeak latency in 13 patients, and 2 interpeak latencies in 4 patients were increased. 26. Clinical value of brain-stem auditory evoked potentials (BAEPs) in hypoxic infants. - - G.A. Chiarenza, S. Oriani, V. Acquistapace, D.R. Bindelli, G.M. Ambrosio and G. Diasio (Milan) In neonatal intensive care units BAEPs are helpful in evaluating the effects of acute conditions such as asphyxia and haemorrhage, and of perinatal audiological risk factors such as hyperbilirubinaemia and otitis media. Long-term studies on the prognostic value of BAEPs regarding the clinical outcome of these newborns are lacking. BAEPs were recorded in 78 full-term normal newborns and 14 infants with asphyxia, 1 m o n t h after discharge from the Unit. Five of the hypoxic infants also had hyperbilirubinaemia. The stimuli were clicks with negative polarity, 0.1 msec duration, at a rate of 9/sec. Potentials from vertex referred to ipsiand contralateral mastoids were recorded after the presentation of 2048 stimuli, repeated twice, from each ear separately at intensities of 20, 40, 60 and 70 dB SL. The latencies of waves l, V and IPL I-V were m~asured and a confidence limit of 0.01 level was used. Three types of BAEP abnormalities were observed: (1) abnormal latency of wave I with normal IPL I-V (4 subjects); (2) normal wave I with abnormal IPL (3 subjects); (3) abnormal waves I, V and IPL I-V (1 subject). In conclusion, BAEPs have a diagnostic value in detecting early audiological deficits after acute asphyxia. 27. Median somatosensory evoked potential (SEP) study in diabetics. - - G. Comi, T. Locatelli, M.F. Ghilardi, V. Martinelli and A. Mandelli (Milan) Peripheral neuropathy is a very frequent complication of diabetes mellitus: almost 2 / 3 of diabetics show some abnormalities in nerve conduction studies. The possibility of spinal cord involvement in diabetes is controversial. We have investigated sensory conduction in peripheral nerves and in central pathways in 30 insulin-dependent diabetics. The median nerve was stimulated at the wrist; evoked responses were recorded at Cv7, Erb's point and scalp. Mean values for all cervical and cortical SEP components were significantly increased in diabetic patients. The interpeak latencies N 9 - N l l , N l l - N 1 3 , E r b - N l l , Erb-N13 were also increased, but not the N13-N20 intervals. Peripheral conduction (PC) was significantly increased in 9 of 30 patients, and central conduction

SOCIETY P R O C E E D I N G S (CC) was significantly increased in 6 of 30 patients. Generally CC was abnormal only in the presence of PC abnormalities. No significant correlation was found between N9, N l l , N13 and N20 absolute latencies and glycocylated hemoglobin levels. Our results can be explained by a contemporaneous involvement of central and peripheral processes of the primary sensory neurons or by an elective loss of faster conducting fibers in peripheral nerves. 28. Analysis of conduction times in the lemniscal pathway. - F. D'AIpa (Catania) By using the 'one-channel' C~-Cv7 recording, conduction times along different tracts of the somatosensory pathway are easily measured. For both experimental and clinical purposes, an 'onset-to-onset' determination is more satisfactory than the commonly performed 'peak-to-peak' determination. The use of low frequency (200 Hz) selective filters can improve the resolution of components, especially the P13-14 complex, even in pathological cases. If conduction time is analysed by measuring 'peak-to-peak" intervals, care should be taken to identify subcomponents of P l l and P13. The response analysis showed that there was a serial link between each short-latency SEP component, including P13, in pathological cases. 29. Cervical somatosensory evoked potential (SEP) abnormalities in multiple sclerosis. - - F. D'Alpa, A.P. Rubicondo and A. Grasso (Catania) The most common SEP abnormality in multiple sclerosis subjects (especially in the early form) is an amplitude reduction of P13 or a reduction of the P13/P11 amplitude ratio. Prolonged intervals (onset-to-onset) between SEP components, are more frequent in the late form and forms with severe sensorymotor defects. The P13 amplitude reduction may be related to P l l abnormalities, particularly a reduction of the P l l b subcomponent, which is found mainly in high cervical or brain-stem sites. The analysis of interval abnormalities suggests a serial origin for every short latency (subcortical) SEP component. 30. Myoclonus. Clinical, electrophysiological and biochemical findings. - - L. Durelli, A. Riccio, M. Delsedime, D. Cocito, C. Barile, P. Benna, C. Bianco, R. Cantello, M. Gilli, G. Gusmaroli, M.T. Perona, 1. Rainero and B. Bergamasco (Turin) Excluding the u n c o m m o n spinal myoclonus, which is associated with a local pathology in the spinal cord, two types of myoclonus can be distinguished on clinical grounds: (a) action myoclonus, which occurs when attempting to sustain a posture or during voluntary movements, and which is stimulus sensitive; (b) spontaneous myoclonus, which is insensitive to somatosensory stimuli. Three members of one family affected by dyssynergia cerebellaris myoclonica are described. They presented with spontaneous myoclonus (an u n c o m m o n finding in this disease)

I T A L I A N EEG SOCIETY, A N N U A L S P R I N G M E E T I N G without concurrent E E G discharges. Cortical VEPs, SEPs and BAEPs were normal. Fifty to 100 msec bursts of E M G activity associated with muscular jerks and abnormal co-activation of inappropriate muscles during ballistic movements were observed. A case of progressive myoclonic epilepsy, with stimulus-sensitive action myoclonus associated with concurrent EEG discharges and E M G bursts lasting 10-30 msec, showed a greatly increased amplitude, while VEPs and BAEPs were normal. The CSF 5-HIAA level was reduced in the patient with action myoclonus and normal in the patients with spontaneous myoclonus. Administration of 5-HTP, a serotonin precursor, improved the former type of myoclonus, while it was ineffective in the latter. This suggests that different biochemical patterns are involved in the pathogenesis of clinically different myoclonus. 31. Brain-stem acoustic evoked potentials (BAEPs) in neurosurgical diseases. - - M. Onofrj, V. D'Annunzio and A. Mangiola (Rome) The origin of BAEPs has been attributed to several nuclei of the brain-stem. More recently it has been suggested that some components have identical origins. We have recorded BAEPs in patients affected by brain-stem haemorrhagic, ischaemic or neoplastic pathologies, and in patients affected by the Arnold-Chiari malformation. The conservation of the first 3 BAEP waves in patients with selective ponto-bulbar pathology, and the markedly delayed V components and normal I-III waves in patients with Arnold-Chiari malformation seem to exclude that BAEPs arise from multiple nuclei. BAEPs were also recorded in some patients by electrodes stereotactically placed ventrally to the brain-stem, in the thalamus and under the inferior colliculus. When recording ventrally to the brain-stem only the V component was inverted in polarity. From the inferior colliculus there was a huge increment of the V components, while from the thalamus there was a diphasic wave of 7.5 msec latency, which was only barely detectable from scalp derivations. The data seem to support the hypothesis that some BAER components have a c o m m o n origin. 32. Simultaneous recording of pattern reversal electroretinograms (ERGs) and VEPs by means of a new ERG electrode. - - M. Onofrj, B. Falsini, B. Ricci and V. D'Annunzio (Rome) Various electrodes are used to obtain pattern reversal ERGs: gold foils, fibre glass and optic contact lenses. We have developed a new electrode for E R G studies, which due to its tolerability over prolonged recording sessions is highly suitable for pattern ERGs. The electrode is a modification of the d'Arsonval electrocorticographic electrode, and consists of a silver chloride spiral, held in cotton wool soaked in isotonic saline solution. Similar to other electrodes, this electrode requires substitution only every 30-60 min, which is sufficient time for clinical recording and, moreover, after substitution the

53P E R G responses do not undergo latency and morphology modifications. In 12 normal subjects the E R G response consisted of a major positive component with latency 6 3 + 3 . 8 msec, and amplitude 3.7 +_1.8 ~V. The interocular latency difference was 0.8 + 1.1 msec. In simultaneous recordings of pattern E R G and VEPs, abnormal VEPs and normal ERGs were detected only in optic neuritis, while primary macular pathology and Parkinson's disease showed a concomitant alteration of the ERGs and VEPs. 33. Visual evoked potentials (VEPs) and pattern electroretinograms (PERGs) in Friedreich's ataxia. - - F. Pinto, A. Amantini, V. Scaioli and G. De Seisciolo (Florence) VEP abnormalities in visually asymptomatic patients with Friedreich's ataxia (FA) are well documented, while there are very few reports on P E R G s in this syndrome. We performed a systematic study of VEPs and PERGs in FA patients to establish a possible retinal contribution to VEP alterations. Nine patients underwent neuro-ophthalmological assessment in conjunction with simultaneous PEV and P E R G recordings. PEVs and P E R G s were elicited by full-field monocular stimulation using a black and white checkerboard pattern with individual squares subtending a visual angle of 60' and 30'. The D T L electrode was employed for PERG recording. Seven out of 9 patients showed VEP abnormalities (increased latency a n d / o r decreased amplitude, as well as ]q'~g0-PTff0 increased temporal dispersion). PERG was undetectable in 2 patients owing to nystagmus; the rest had normal responses. No patient noticed visual impairment and clinical evidence of optic atrophy was absent. Although a ganglional origin of the P E R G has not yet been established, the present study seems to exclude that the anterior visual pathways contribute significantly to VEP abnormalities in FA. Varying degrees of fibre loss in the optic nerve and tracts have been found in neuropathological examinations. However, primary axonal degeneration cannot explain all the features of VEP changes observed in this study. 34. Neurophysiological assessment of the optic pathways in childhood insulin-dependent diabetes. - - A. Polo, L.G. Bongiovanni, A. Fiaschi, G. Serra, C. Perli, L. Pinelli and D. De Grandis (Verona) Neurological complications are frequent in patients with diabetes mellitus. The early detection of neurological complications is an important task in the follow-up of the disease. In order to evaluate the involvement of the optic pathways, we have studied evoked potentials by pattern stimuli (VEPs and ERGs) and oscillatory potentials obtained by bright flashes in 30 children with insulin-dependent diabetes and in 30 controls with the same age range. Autonomic nervous system function was also tested. Electroneurophysiological data were statistically compared between the control and diabetic groups. Only patients with high Hb Ale levels showed significant neurophysiological alterations and impairment of autonomic nervous system function.

54P 35. Brain-stem auditory evoked potentials in the evaluation of subtentorial hematomas. - - G. Pozzessere, G. Sancesario, R. Massa, M. Caramia and P.A. Rizzo (Rome) Brain-stem auditory evoked potentials (BAERs) were recorded in 5 patients suffering from subtentorial hematomas. Each patient underwent an initial recording within 72 h of the clinical onset; follow-up recording sessions were performed after 1 and 3 months, Three patients, with intra-axial brain-stem hematomas (case 1: pontine-mesencephalic hematoma; cases 2 and 3: pontine hematoma), displayed a BAEP alteration confined to peaks III-V. One (case 4) out of the 2 patients with extra-axial h e m a t o m a s showed clinical and CT signs of brainstem compression and displacements. BAEPs were bilaterally and diffusely altered in this patient. BAEPs were normal in case 5, which bad no signs of brain-stem compression or displacement. During follow-up, the BAEP alterations showed a partial to total recovery in cases 2 and 4, suggesting the presence of a reversible damage of the acoustic pathways. Conversely, in cases I and 3 BAEP alterations remained unchanged in time, suggesting the existence of an irreversible lesion. In conclusion, BAEP recording proved to be a useful method to evaluate the damage caused in brain-stem structures by subtentorial hematomas. 36~ Cortical potentials evoked by tooth pulp stimulation in the rabbit: modifications induced by protracted pain, morphine, and naloxone. - - P.A. Rizzo, L. Sanarelli, G. Soldati, M.C. Setacci, G.L. Mattioli and F. Pierelli (Rome and Latina) Trigeminal evoked potentials (TEPs) by tooth pulp stimulation, EEG and ECG, were recorded in adult rabbits. A condition of protracted and diffuse painful stimulation was produced by intraperitoneal injection of phenol 5%. TEPs recorded under these conditions showed a significant voltage increase ( P < 0.01) of all components (N36-P47, P47-N62, N62-P85), while latencies remained substantially unmodified. The EEG was characterized by the presence of fast activity and the ECG showed a marked increase of pulse rate. These findings may be related to a diffuse activation of the nociceptive system, induced by a prolonged and continuous painful stimulation (intraperitoneal phenol). Morphine injection produced a rapid recovery of TEP voltages with a return to the control levels and normalization of the EEG and ECG. A successive naloxone administration induced a significant increase of the TEP voltage ( P < 0.01) of the later components (N62-P85). 37. Somatosensory evoked potentials (SEPs) in Friedreich's ataxia (FA). - - L. Rossi, G. de Scisciolo, A. Bindi, S. Constantini, P. Marini and R. Zappoli (Florence) SEPs have been studied in 10 patients affected by 'typical' FA. All patients underwent prior E M G examinations and nerve conduction studies. The peripheral and central components of SEPs were obtained by stimulation of the median nerve at the wrist and at the elbow, and were recorded over the clavicle, seventh cervical spine and the hand area of the con-

SOCIETY P R O C E E D I N G S tralateral somatosensory cortex to median nerve stimulation. Precocious SEP abnormalities were observed in all patients, independent of the duration and severity of the illness. There was attenuation of the clavicular and major cervical potentials in association with a normal or near normal latency. All patients showed a normal sensory conduction velocity between stimulation sites at the wrist and at the elbow. We consistently observed delayed P]4, N~2-0, 1Y25 waves in association with a significant increase of N'20 temporal dispersion. It appears that the pattern of SEP abnormalities in FA is sufficiently characteristic and suggestive of slowed conduction in the central pathways. Clinically, the study of SEPs could be useful as a complementary method of early diagnosis in FA. .38. Somatosenso~ evoked potentials (SSEPs) and brain-stem evoked potentials (BAERs) in some neurodegenerative diseases. - - P.M. Rossini and J.B. Craceo (Rome, and New York, NY, U.S.A.) o

Twenty-five patients with neurodegenerative diseases (9 Friedreich's ataxias, 7 hereditary motor-sensory neuropathies (HMSN), 3 familial spastic paraplegias, 3 olivo-ponto-cerebellar atrophies; 1 late onset cerebellar ataxia, 1 ataxia telangectasia, 1 a-beta lipoproteinemia) were examined. BAERs were altered in 39% of cases without a clear-cut distribution in the various syndromes. The follow-up of the a-beta lipoproteinemia patient showed a progressive normalization of both BAERs and the ataxia gait after a prolonged high dosage vitamin E treatment. Median and peroneal nerve scalp and spinal SSEPs were altered in about 65% of cases. Erb and lumbar responses were often small or absent in Friedreich's ataxia; they were delayed in HMSN. Central conduction times were prolonged in Friedreich's ataxia and olivo-ponto-cerebellar atrophy, while they were frequently normal in HMSN and invariably in familial spastic paraplegia. Lower limb spinal and scalp SEPs progressively deteriorated in a patient with H M S N type II during a 4 year follow-up. 39. A new method to stimulate the unexposed motor cortex through low voltage stimuli. - - P.M. Rossini, N. Hassan and R.Q. Cracco (Rome, and New York, NY, U.S.A.) Two methods of electrically depolarizing the motor cortex for hand and foot through the intact scalp were compared in 8 healthy volunteers. One method consisted of stimulating the scalp through two flat square copper electrodes (3 cm 2) placed 3 cm apart on the hand or leg scalp motor area. In the second method a flexible steel belt cathode was wrapped around the head 2 - 3 cm above the nasion-inion plane and a flat circular anode (4.8 cm 2) was placed on the scalp area to be stimulated. Motor action potentials with similar amplitudes and latency were recorded over thenar and leg muscles with both stimulating methods. However, the stimulus intensity using the belt cathode was about 1 / 1 0 that required when using the bipolar stimulating electrodes (about 100 V in the former, more than 1000 V in the latter). This difference is attributed to differences

I T A L I A N EEG SOCIETY, A N N U A L S P R I N G M E E T I N G in the orientation of the electric fields generated by the two kinds of stimuli.

40. Acoustic brain-stem responses in patients submitted to Hoiter electrocardiographic monitoring. - - R. Schoenhuber, D. Bouzas, M.C. Guersoni, G. Di Donato, A. Orlando, M. Scarano and C. Mazzetti (Modena) Acoustic brain-stem responses (ABRs) were recorded in 40 patients, 29 males and 11 females, with a mean age of 54 years (range 9-76), submitted to Holter 24 h ECG monitoring. Twelve patients were examined because of syncope, the other 28 because of dizziness. Holter monitoring showed no abnormalities in 11 patients. A B R interpeak latencies were abnormal in 12 patients, 2 of them with syncope, 10 with dizziness and in 2 with positive and 10 negative Holter. The prevalence of A B R abnormalities does not seem to differ between patients with syncope or dizziness (X 2 =1.45), or between those with positive or negative Holter examination (X 2 = 1.01).

41. A quantitative analysis of the pattern electroretinogram. Preliminary report. - - M. Manca, G. Serra, D. De Grandis, R. Eleopra, M. Bottoni, V. Tugnoli and M. Carreras (Ferrara and Verona) Pattern electroretinograms (PERGs) appear to be related to ganglion cell activity. P E R G s and visual evoked potentials (VEPs) were concomitantly recorded in 20 normal subjects by using a TV monitor checkerboard pattern reversal stimulus with checks of 60' and 15' in order to quantify these parameters for clinical use. The mean b wave P E R G latency was 60.2 msec, S.D. 3.5, and 63.2 msec, S.D. 6.19, for 60' and 15' checks, respectively. The relevant mean amplitudes were 2.5 /~V, S.D. 0.5, and 1.8 /~V, S.D. 0.7. Both latencies and amplitudes were significantly different between checks of 60' and 15' ( P < 0.01). The mean Ploo-b wave latency differences were 47.8 msec, S.D. 4.1, and 53.8 msec, S.D. 7.8, for checks of 60' and 15', respectively.

42. Brain-stem evoked potentials (BAEPs) in subjects with cranio-vertehral malformations: analysis of short-term and long-term follow-up after surgery. - - D. Sollazzo, P. Bruni and S. Esposito (Rome) We report data concerning 42 monaural BAEPs recorded from 10 patients with cranio-vertebral malformations represented by occipitalization of the atlas and basilar invagination. Of 8 preoperative BAEPs recorded from 3 subjects, 6 showed an increase of I-III interpeak latency (IPL). Of 28 BAEPs recorded a short time after surgery, from 1 to 12 months, 21 showed an abnormal delay of I-HI IPL. On the other hand, of 6 BAEPs recorded from 3 subjects 20 years after surgery, 5 were in the normal range and 1 revealed an abnormal I-Ill IPL. Even if the most important site of lesion in cranio-vertebral malformations is the cervico-medullary junction, the results reported are suggestive of a unilateral involvement or of a

55P bilateral but largely asymmetric involvement of the medullopontine junction, which is explored by wave lIl in a high percentage of patients suffering from this disorder.

43. Effects of chronic respiratory insufficiency on the peripheral nervous system. A neurophysiological study. - - S. Barbieri, G. Valli, P. Sergi, P. Berardinelli and G. Scarlato (Milan) Nineteen patients with chronic respiratory insufficiency, mean age 61.4_+12.2, and without other possible causes of peripheral nervous system involvement have been investigated with pulmonary function tests, clinical neurological examinations and neurophysiological methods including motor and sensory conduction studies and needle electromyography. The E M G was abnormal in 94.7% of the cases and showed an increased percentage of polyphasic potentials and a reduced recruitment pattern of motor units firing at high frequency, while the motor and sensory conduction studies were normal with the exception of a reduced compound muscle action potential of the APB and EDB muscles. Our data seem to support the hypothesis of an involvement of the motoneurons in this condition, while there is no evidence for a neuropathy. These results are in agreement with various studies that demonstrate the greater susceptibility of the spinal cells to anoxia and the relative resistance of the nerve trunks.

44. Prevalence of carpal tunnel syndrome in diabetics: effects of age, sex, diabetes duration and polyneuropathy. - - G. Coral, L. Lozza, G. Galardi, M.F. Ghilardi and S. Madaglini (Milan) Diabetic neuropathy is generally held to be a predisposing factor to entrapment syndromes. Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy; females and old people are most frequently affected. The prevalence of CTS in diabetics, and associated risk factors are studied in this work. Clinical and electrophysiological examinations were performed in 401 patients (208 males and 193 females) affected by insulin-dependent and insulin-independent diabetes. Median nerve sensory and motor conduction velocity, ulnar and peroneal nerve motor conduction velocity and sural nerve sensory conduction velocity were investigated in all patients. Criteria for CTS diagnosis were the presence of slowed median nerve sensory conduction in the palm-wrist tract and increased distal motor latency. Polyneuropathy was defined by a slowing of conduction velocity in two or more nerves. Forty-five patients (11.2%), 36 females and 9 males, showed CTS. Peripheral neuropathy was found in 168. Greatest risk factors for CTS, in order of importance, were: female sex, older age and presence of neuropathy. Polyneuropathy but not CTS was related to duration of diabetes.

45. Analysis of the F response on single motor units. - - D. De Grandis, A. Fiasehi, G. Sciarretta, 1. Aiello, A. Cantini and G. Serra (Verona, Sassari, Prato and Ferrara) Most of the F waves with an identical morphology and with a latency variation within 100/zsec recorded from EDB muscles

56P by stimulating the peroneal nerve at the ankle are single motor unit potentials. It is thus possible to study several motor unit parameters such as amplitude and latency with different recordings. In normal subjects we observed a wide variability of motor unit amplitude depending on its location, and found a different correlation between minimal and mean F wave latencies compared with height. F wave latency was independent of the subject's height. The range between the minimal and maximal single motor unit recurrent response increased with age. From a comparison of the M response area with the average area of random different F responses of single motor units it is possible to calculate an index ( M / R ) related to several variables, including the number of muscle motor units and amplitude. We found that in normal subjects this index varied depending on age. On the contrary, at repeated trials these values were stable in the same subjects. 46. Experimental allergic neuritis in rats: study of neurophysiological parameters. - - E. Di Stefano, D. Gambi, A. Uncini and N. Di Cesare (Chieti) Intraneural injection (20 /~1) of sera from adult Hartley guinea pigs with experimental allergic encephalomyelitis induces demyelinated patterns in the sciatic nerve of rats. Conduction block studies were performed by means of stimulation (0.1 msec duration), directly at the sciatic notch and percutaneously at the ankle. Evoked muscle action potentials were recorded using an active electrode, placed on the dorsal surface of the foot (skin electrode). Evoked potential latencies and amplitudes were measured baseline to peak, following supramaximal nerve stimulation. The conduction block was evaluated during the course of demyelinating processes. 47. Effect of a-adrenergic block on spasticity. - - G. Masi, L. Lochi and E. Ferrannini (Bari) In a group of 6 patients affected by spasticity, T-H responses and the motoneurone excitability curve were studied before and after the venous infusion of timoxamine, an aadrenergic blocker. The H response and the late facilitation of the motoneurone excitability curve were less decreased than the T response after c~-adrenergic block. These findings show that timoxamine exerts a direct central inhibitory action. 48. Carpal tunnel syndrome (CTS) in long-term dialysed patients: pathogenetic hypotheses. - - C. Paganl, C. Zoerle, M.C. Guaita, C. Bazzi, C. Sorgato and G. Torti (Milan) CTS has been investigated clinically and electromyographically in 117 patients under regular dialytic treatment (RDT) from 5 to 190 months: 11 patients (9.4%) had CTS, bilateral in 8. CTS was more frequent in females than in males (26.2% vs. 16.6%) and was correlated with chronological age (54.4 years vs. 45.8 years, respectively in patients with and without CTS: P < 0.025) and with dialytic age: no patient with a dialytic age < 5 years had CTS; 2 out of 34 patients (5.8%) in R D T from 5

SOCIETY P R O C E E D I N G S to 10 years and 9 out of 37 (24.3%) in R D T > 10 years had the syndrome. CTS was correlated with the severity of the electrical polyneuropathy (with P from <0.05 to < 0.01 for 5 of 13 examined electroneurographic parameters). CTS was not correlated with section of the radial artery at the wrist, or with the number of surgical procedures for vascular shunt, or with the mean interdialytic weight increases. We discuss the pathogenetic role of the vascular shunt; secondary for the dominant hand, with no shunt 5 times out of 11, and probably crucial for the non-dominant hand, with a vascular shunt in 7 out of 8 patients. Seven patients were successfully operated, with no relapses. 49. Clinical-electrophysiological correlation in carpal tunnel syndrome. - - G. Pavesi, M.F. Olivieri, A. Misk and D. Mancia (Parma) We examined 56 cases of carpal tunnel syndrome. Each patient was investigated clinically and electromyographically. The clinical examination aimed at evaluating the presence of sensory and motor deficits, and at assessing the coexistence of other pathologies. The purpose of our study was to establish the existence of a correlation between clinical signs and symptoms and electromyographic data. A significant correlation between the amplitude of sensory action potentials and sensory deficits, and also between distal motor latency of median nerve and motor deficits has been found. 50. Neurophysiological features of transitory neonatal myasthenia. - - C. Scoppetta, P. David, C. Casali, E. Bartoccioni and M.L. Vaccario (Rome) Some newborns of myasthenic mothers present transient myasthenic signs due to transplacental passage of antiacetylcholine receptor antibodies (anti-AChR). On 7 newborns and their myasthenic mothers, electromyographic (EMG) tests of repetitive supramaximal stimulation were performed, and anti-AChR was titered. One newborn presented a severe myasthenic syndrome with respiratory weakness, three had mild myasthenia. All of them completely recovered within 1-6 weeks. Anti-AChR was present in all 4 myasthenic newborns and also in two of the 3 babies who showed no myasthenic signs. Anti-AChR was found in sera long after clinical and E M G signs of disorders of neuromuscular transmission had disappeared. No correlation was found between the following: (a) severity of maternal myasthenia; (b) severity and duration of neonatal myasthenia; (c) mother's anti-AChR titer; (d) newborn's anti-AChR titer. Neonatal myasthenia in our series appeared more frequently than reported in the literature. In cases of delivery of a myasthenic patient, anticholinesterasic drug treatment, and mechanical ventilation of the newborn should be foreseen. Blood or plasma exchanges should be considered in the more severe cases.

I T A L I A N EEG SOCIETY, A N N U A L S P R I N G M E E T I N G 51. Electrophysiological study in vivo of muscle fiber function in congenital paramyotonia. - - W. Troni, L. Bergamini, C. Doriguzzi, T. Mongini and D. Schiffer (Turin) In 2 patients of a family suffering from congenital paramyotonia (Von Eulemburg) we studied: (1) the conduction velocity in muscle fibers of the biceps brachii (m-CV); (2) the effects induced by repetitive stimulation and by changing the intramuscular temperature (iT) on conduction velocity and on the excitability of single muscle fibers. The results are summarized as follows: (1) m-CV was reduced in both patients; conduction slowing cannot be explained by muscle fiber shrinkage as demonstrated by the quantitative analysis on muscle biopsy. (2) Inexcitability of muscle fibers always occurred at iT values ranging between 22 and 24°C and persisted during rewarming. However, the CV variations of the paramyotonic fibers to iT changes were normal. (3) Repetitive stimulation at 20 Hz always induced a block of fiber activity, not preceded by changes of the latency and voltage of the potentials, which persisted at lower stimulation frequencies. 52. Cinematic and E M G analysis of ballistic arm movements in cerebellar patients. - - N. Accornero, A. Berardelli, M. Argenta, S. Ricci and M. Manfredi (Rome) The trajectory and the E M G activity during two joint fast arm movements have been studied in 6 patients with cerebellar lesions. The patients were seated on a chair with the elbow and shoulder free and were instructed to draw, as fast as possible, geometric figures of different shapes and sizes on a graphic board interfaced with a microcomputer. The E M G was recorded from the biceps, triceps, pectoralis major and posterior deltoid, rectified and integrated by means of surface electrodes. The E M G pattern was characterized by a large number of E M G bursts and by co-contraction activity in all the muscles tested. In addition, the EMG bursts had a prolonged duration in comparison to normal subjects. The patients took longer than normal subjects to draw the geometric figures. Each segment of the figure was irregular and not straight or curvilinear as in the drawings by normal subjects. 53. Masseter silent period by electrical stimulation of the first trigeminal division. - - R. Agostino, G. Cruccu, M. Fornarelli, M. Inghilleri and M. Manfredi (Rome) In 7 normal subjects electrical stimulation (0.1-0.3 msec, 20-45 mA) of the supraorbital nerve, constantly evoked a bilateral silent period (SP) in the voluntary electromyogram of jaw closing muscles (mean latency 35.1_+11.1 msec, mean duration 40.4_+ 11.1 msec), called SP2. In addition, in 5 subjects there was an early E M G SP called SP1, usually less evident than SP2 (mean latency 10.9_+ 1.86 msec, mean duration 16.1_+7.64 msec). N o significant difference in the SPs between ipsilateral and contralateral sides, or between masseter and temporalis muscles, has been observed. The thresholds of the electrical stimuli evoking SPs were identical and this sug-

57P gests that both SPs may be mediated by the same afferent axons. By increasing the stimulus intensity and by using repetitive stimulation, SP2 showed a greater latency gain and was more easily habituated than SP1. These two features suggest a polysynaptic organization of both SPs in the brain-stem, with the SP2 pathway involving more synapses. 54. Correlation between insulin secretion and neuropathic disorders in type II diabetic patients. - - 1. Aiello, M. Maioli, G. Rosati, A. Demurtas, A. Pacifico, T. Pulina and S. Traccis (Sassari) A previous study performed on type 1I diabetic patients showed a significant decrease in conduction velocity and a significant increase in HB AI~ in patients with a low induced serum-insulin peak. We suggested that high insulin secretory reserve protects against neuropathic disorders, and that this effect is mediated by a better metabolic control. To verify this hypothesis we studied two other groups of type II diabetics with a high (95.5 # U / m l = ,X + S.D. of normal values) and low (28.9 p , M / m l = X - S . D . of normal values) insulin secretory reserve, but with Hb Ale values in the 7 9% range to minimize the effects of a different metabolic impairment. There were no significant differences in electroneurographic parameters between the two groups of patients. These data confirm that neuropathic disorders in type II diabetics are related to metabolic impairment and not directly to the insulin secretory reserve. 55. M wave area in axonai and demyelinating neuropathies. - I. Aiello, G. Rosati, A. Demurtas, I. Pirastru, G. Demontis and S. Traccis (Sassari) A study of the M wave area may provide information on nerve fibre conduction block independent of local trauma in peripheral neuropathies. On supramaximal stimulation of impaired peripheral nerves with fibre conduction blocks, it is reasonable to assume that the M wave area obtained on distal stimulation (Ad) is larger than that obtained on proximal stimulation (Ap). This decrease in M wave area can be expressed as the ratio A d / A p per cent. In the present report normal values of A d / A p were calculated for the ulnar, median, peroneal and posterior tibial nerves. The A d / A p for the same nerves was also determined in patients affected by axonal and demyelinating neuropathies. The A d / A p ratio was always within normal range in axonal neuropathies, but not in demyelinating neuropathies. 56. The use of the flexor reflex of the lower limb (femoral biceps) in the study of polyneuropathies. - - F. Bellini, M. Bartelli, O. Ronchi and G. Marconi (Florence) The flexor reflex was studied in patients with a disorder of the peripheral nervous system. The reflex, consisting of components RII and RIII, was evoked by stimulating the sural nerve and recording the E M G response from the femoral biceps in 23 healthy subjects and 49 patients, 43 with chronic distal neu-

58P ropathy (DN), 3 with Guillain-Barr6 radiculopolyneuritis (GB) and 3 with Friedreich's disease (FD). Peroneal nerve MCV and sural nerve SCV were measured in all patients. The only significant finding was a correlation between the two responses and SCV in controls. In DN patients the latencies of the two components were significantly longer than normal, indicating that the fibers of the reflex arch are also affected. However, the percentage of patients with latencies longer than 2 S.D.s above average was low (23% for RII and 40~; for Rill). In GB patients the two components were clearly delayed compared with DP patients. The latencies reduced noticeably after treatment with plasma exchange parallel with clinical improvement, while the MCV showed a slower and less significant normalization. 57. Electrophysiological findings and monosynaptic reflexes in vincristine neuropathy. - - F. Bravaccio and A. Ammendola (Naples) This electrophysiological longitudinal study refers to a group of 6 leukaemic children: 5 treated with vincristine for a long period, and one for a short period. The disappearance of the soleus T reflex occurred before the disappearance of the H reflex: the depression of the M response of the extensor digitorum brevis was clearly more evident than that of the soleus. In the case treated for a short time (a few months) with vmcristine there was complete recovery, while in the other 5 there was partial recovery. The motor conduction velocity of the peroneal nerve was not significantly modified. The results are as follows: (a) the vincristine neuropathy shows an initial involvement of the distal parts of the nerve fibers with subsequent proximal spread, i.e., a distal axonal degeneration with a ~dying-back' process; (b) it is reversible when the therapy is stopped: this shows a clear relation between dose duration of the treatment and neurotoxic effects. 58. The nosography of Roussy-Levy syndrome; a new family presenting a dominantly inherited motor-sensory, hypertrophic neuropathy with early appearance and benign course. - - F. Bravaccio, A. Ammendola, G. Di Iorio and R. Cotrufo (Naples) A 36-year-old woman presented, since she was 3, with club feet and walking difficulties, and a benign course of the disease, which seemed non-progressive until the 33rd year of age. Neurological examination showed absence of dorsiflexion of feet and steppage gait. distal muscle wasting and generalized areflexia. EMG showed typical neurogenic alterations. Motor and sensory conduction velocities were greatly reduced. Long peroneal muscle biopsy showed a picture of neurogenic atrophy. Superficial peroneal nerve biopsy showed a marked loss of larger axons because of axonal atrophy, decreased density of nerve fibres, aspects of demyelination and remyelination, many onion bulb formations, increased connective components in the endoncrve. Several relatives of our patient in all the 3 generations examined presented club feet, generalized areflexia, steppage

SOCIETY P R O C E E D I N G S gait, neurogenic alterations of EMG, decreased motor conduction velocities. The Roussy-L6vy form of hereditary motor and sensory neuropathy with nerve hypertrophy, transmitted as an autosomal dominant character, was diagnosed. 59. Guillain~Barre syndrome: critical evaluation of immunosuppressive therapies. - - D. Cocito, L. Durelli and M.T. Perona (Turin) On the assumption that the Guillain-Barre syndrome (GBS) has an autoimmune pathogenesis, steroids, immunosuppressants and plasmaphoresis have been tried in its treatment. .According to recent controlled studies, however, they do not seem to affect the natural history of the disease. In a prospective-retrospective study of 24 GBS patients we compared 3 groups: one on corticosteroids, one on plasmaphoresis and the third untreated. The 3 groups were compared for: time between onset and admission, disability rating on admission, rate of improvement and disability rating at follow-up. On the evidence of these data neither treatment affected the time course or final outcome of the disease. Since both steroids and plasmaphoresis are frequently attended by side effects, some of which are severe, the treatment of GBS should be accompanied by close monitoring of the vital functions, prevention of infection and physiokinesitherapy. 60. M u ~ l e fibre conduction velocity during ischaemia. - - V. Contegiacomo, M. De Mattei and W. Troni (Turin) Conduction velocity (CV) in single fibres of the brachio-radial muscle has been determined in 10 normal subjects during ischaemia induced by a pneumatic cuff applied to the arm and lasting 30 rain. No CV variations were observed in the fibres examined throughout the period of ischaemia, using low frequency stimulation (0.5 Hz). On the contrary, ischaemia significantly potentiated the decrease of CV induced by prolonged stimulation at l0 Hz. 61. A clinical study of autonomic and peripheral neuropathies in juvenile diabetes. - - M.C. Cristofori, G. Serra, P.L. Pareschi, I. Aiello, M. Manca, R. Eleopra, M. Bottoni and V. Tugnoli (Ferrara and Sassari) The Valsalva ratio, beat-to-beat test, handgrip test for autonomic system functions, and H index from soleus muscle for peripheral neuropathy were investigated in 25 subjects affected by insulin-treated juvenile diabetes mellitus. Seventy-six per cent of patients presented H index abnormalities, which were very marked in 12%. Sixteen per cent presented autonomic system dysfunctions. No correlation with metabolic control or duration of the disease was found, even though patients with a disease duration of over 20 years presented significant abnormalities.

ITALIAN EEG SOCIETY, A N N U A L S P R I N G M E E T I N G 62. Autonomic function and peripheral nerve conduction velocity: correlative study in uraemic patients. - - R. Dattola, G. Vita, P. Girlanda, R. Calabr6, L. Manna, C. Venuto, A. Toscano, V. Savica and G. Belliaghieri (Messina) The pattern of autonomic nervous system disturbances was studied in 18 patients on chronic intermittent haemodialysis by simple non-invasive tests. These included the Valsalva manoeuvre, deep breathing test, measurement of the changes in blood pressure following standing up, 30/15 ratio, handgrip test and beat to beat variation test. We also measured motor and orthodromic sensory conduction velocities (CV) of the posterior tibial nerve. The 30/15 ratio and beat to beat variation were found to be significantly correlated (r = 0.58: P < 0.01) with sensory CV values in the group as a whole. When patients were divided into two groups with normal or abnormal 30/15 ratios, those with abnormal ratios had significantly ( P < 0.05) lower sensory and motor CV measurements. The 30/15 ratio and beat to beat variation test are simple ways of testing autonomic function in haemodialysis patients. 63. Unusual, acute supracapsular nerve lesion: clinical and E M G report of a case. - - P. David, A. Uncini, M. Lupinello and P. Tonali (Rome) We report the case of a 27-year-old male who, during karate training, performed an extreme hyperextension and hyperabduction of the left shoulder, which caused a sudden deep pain in the left shoulder followed by weakness in abduction and external rotation of the arm. About 1 month later a progressive atrophy of the supra- and infraspinatus muscles developed. EMG showed a persistent picture of total denervation confined to the left supra- and infraspinatus muscles. An initial clinical recovery confirmed by E M G findings of reinnervation in the supraspinatus muscle occurred only 13 months after the occurrence of the lesion. In our case the presence of a narrow suprascapular notch detected in a particular X-ray projection may have produced an unusual compression of the suprascapular nerve against the sharp inferior margin of the suprascapular ligament during an extreme hyperextension and hyperabduction of the shoulder, the so-called 'sling effect.' The late and still incomplete recovery suggests that the treatment of choice, as in suprascapular entrapment neuropathy, is the resection of the suprascapular ligament. This results in a quicker and more effective recovery and prevents the recurrence of nerve compression. 64. Electrophysiological findings in peroneal muscular atrophy (PMA). - - F.A. De Falco, V. Rossi, A. Fels, G. Grasso, F. Barbieri and O. Sepe Visconti (Naples) A complete electrophysiological study was carried out on 12 members of a family with dominantly inherited PMA. Sural nerve biopsy was obtained in 2 patients. Motor (MCV) and sensory (SCV) conduction velocities along the median nerve were slowed in all the affected mem-

59P bers (mother and 3 sons) to less than 60% of normal (hypertrophic type of PMA). However, SCV values were slightly below (in 1 case above) the dividing line set at 60% of normal. MCV along the median nerve was borderline at the value of 38 m / s e e proposed by Harding and Thomas (1980) and was in the 25-45 m / s e e range set by Davis et al. (1978) for their 'intermediate' group. MCV along the posterior tibial nerve was more severely reduced in all patients (average slowing to 12.2% of normal) and highly supported the diagnosis of the hypertrophic type of PMA, in agreement with pathological data. SCV along this nerve might be unrecordable because of the poor amplitude of sensory potentials. Nevertheless, the study of MCV and SCV in both median and posterior tibial nerves is indispensable to distinguish different subgroups in PMA and questions the existence of an ' intermediate" group. 65. Preliminary, results on repetitive stimulation of human muscle fibres in situ. - - M. De Mattei, V. Contegiacomo and W. Troni (Turin) The effects induced by repetitive stimulation of single muscle fibres were studied in the brachial biceps muscle in 20 normal subjects (10 males and 10 females) ranging in age between 20 and 65 years. Repetitive trains of short duration (3 5 sec) at increasing frequency (5, 10, 20 Hz) induced a constant increase of velocity in all the tested fibres, which was positively correlated with the stimulation frequency. The mean latency decrease induced by varying the stimulation frequency from 1 to 20 Hz was 1.9 msec (range: 1.5-2.5 msec). Prolonged stimulation (up to 10 rain) at a frequency of 10 Hz induced a constant and progressive decrease of CV, although highly variable in individual fibres. The mean CV r e d u c t i o n / m i n was 0.18 m / s e e (range: 0.05-0.43 m/see). 66. The Melkersson-Rosenthal syndrome: an electrophysiological and immunological study. - - L. Durelli, D. Cocito and M. Delsedimc (Turin) The Melkersson-Rosenthal syndrome, characterized by recurrent peripheral facial palsy, facial oedema and 'lingua plicata,' is a rare disease of obscure aetiology. It has been attributed both to a familial degenerative disease of the sympathetic neurones and to an autoimmune disease of the nervous system. We described a non-familial case where no deficit of sympathetic functions was detected. On the other hand, a strikingly high IgG synthesis rate was found in the cerebral spinal fluid. This value (168.46 m g / d a y ) , which is even higher than that found in definite multiple sclerosis patients, was specific for IgG and was associated with IgG polyclonal bands on cellogel RS electrophoresis of cerebral spinal fluid and serum. EEG, brain-stem auditory evoked potentials and pattern reversal evoked potentials were normal. Serum antibody titre against rubella virus was slightly elevated in the absence of recent infection. These data suggest an immunological disorder.

60P 67. Electromyographic analysis of the stretch reflex induced in the triceps surae by a fall. - - M. Frascarelli (Rome) The stretch reflex induced in the triceps surae by a fall from a platform has been studied in 15 volunteers. The spinal (MSR) and the supraspinal (FSR) responses have been investigated in 2 different experimental conditions (open and closed eyes). The amplitude of the spinal response appears to be correlated with the level of activation of the tibialis anterior muscle. The amplitude of the supraspinal response increases, in the same subject, with the visual deafferentation. It may be hypothesized that a process of very quick compensation, strictly depending on the degree of tibialis anterior activation, is produced, at spinal level, by the fall. If the modulation of the sensory inputs is not correct, a more complicated phenomenon of adaptation, acting at supraspinal level, is probably induced. 68. Electrophysiological study of the snout reflex in normal subjects and in parkinsonian and pseudobuibar patients. - P. Girlanda, M.L. Roberto, R. Dattola, L. Morgante, C. Venuto and C. Messina (Messina) The snout reflex appeared to be electrophysiologically present in the majority of normal subjects. A facilitation of the R 2 responses of the snout reflex was found in parkinsonian patients, while there was an increase in the R 1 in pseudobulbar patients. The behaviour of the snout reflex therefore resembles that of the blink reflex• These findings could be due to the different effects exerted by lesions of the lateral and the ventral motor system upon the oligo- and multi-synaptic reflexes. 69. Neuropathic effects of treatment with nitrofurantoin and amiodarone. - - N. Marcello and S. Terenziani (Reggio Emilia) We report the case of a 71-year-old patient under treatment with cordarone for 2 years. Because of urinary infection he was given furadantin, but the patient gave up taking this therapy because of dysesthesia and hyposthenia, mainly in the distal portions of the limbs. However, the symptoms did not disappear until treatment with amiodarone was also interrupted. Electrophysiological examinations showed considerable delay of distal latencies, and an E M G showed signs of denervation which disappeared after gtopping amiodarone treatment. Both nitrofurantoin and amiodarone seem to be involved in causing the type of neuropathy described above, because symptoms appear after administration of furadantin in a dosage which is not sufficient to cause severe neurotoxic effects; an improvement was observed only after interrupting amiodarone treatment. It should also be emphasized that both drugs are furanic derivates.

SOCIETY P R O C E E D I N G S taken for a spastic Babinski responsive bilateral paraparesis, diaphragmatic disability immediately occurred. Early percutaneous stimulation at the posterior edge of the sternocleidomastoid muscle at the level of the upper edge of the thyroid cartilage did not evoke any motor action potentials. Surface electrodes, placed in the eighth intercostal space on the anterior axillary line, were employed. Six months later the patient improved. Stimulation of phrenic nerves revealed a motor action potential latency and amplitude of 6.5 msec and 450/tV, respectively, on the left side, and 6.3 msec and 440 ~V on the right side. One year later the patient could be weaned. The diaphragmatic disability in the present case is the result of a phrenic neuroapraxia as shown by: (1) the early, bilateral and complete paralysis of phrenic nerves; (2) the complete return to normal function. 71. Experimental chronic compression of the sciatic nerve in rabbits: functional and morphological correlations. - - A. Moglia, M. Sanlungo, R. Scelsi, E. AIfonsi, M. Lombardi, P. Poggi, C. Zandrini and A. Arrigo (Pavia) Twenty New Zealand rabbits were given general anesthesia and the sciatic nerve was constricted by means of a strip of aponeurotic sheath, slightly lifting the nerve from its space. Fibrillation activity, slowing of the maximal motor and sensory conduction velocities, and reduction of the amplitude of the motor and sensory action potentials were observed 4 weeks after the entrapment. An external neurolysis was performed in 10 animals. Two months after decompression fibrillation activity was absent, and there was partial recovery of maximal motor and sensory conduction velocities and sensory action potential amplitude. Histological and morphological patterns observed 4 weeks after the entrapment and 2 months after decompression, were in agreement with the functional findings. 72. A case of postpartum foot drop. - - F. Morello, G. Cagnin, E. Benetello and B. Bertolo (Castelfranco Veneto) The occurrence of obstetric palsies in mothers is estimated to be 1 in every 2600-6400 deliveries, including those involving surgical procedures. We report a case of postpartum foot drop in a previously healthy, 40-year-old woman at her fourth pregnancy. Weakness and sensory impairment were maximal in the areas corresponding to the distribution of the right peroneal nerve, but gluteus and hamstring muscles were also involved. Electrophysiological study excluded a compression of the peroneal nerve as it crosses the fibular head, confirming the suspicion of injury to the right lumbo-sacral cord. It is feasible that the lumbo-sacral cord was compressed against the sacral ala by the fetal head in its rotation and descent during the second stage of labour.

70. Diaphragmatic function recovery after postoperative phrenic neuroapraxia. - - G. Masi, T. Fiore and M. Buono (Bari)

73. Hyperproteinorrachia in Eaton-Lambert myasthenic syndrome. - - F. Morello, G. Cagnin and V. Toso (Castelfranco Veneto)

A case of respiratory failure with diaphragmatic paralysis is presented. After upper cervical cord decompression, under-

We report a case of paraneoplastic Eaton-Lambert myasthenic syndrome with the unusual symptoms of cranial

ITALIAN LEG SOCIETY. A N N U A L SPRING MEETING nerve involvement, mild peripheral motor nerve disorder on EMG examination and high protein cerebrospinal fluid level (125 mg%). At first diagnosed by us as polyradiculoneuropathy, the clinical course and EMG findings later demonstrated that it was a myasthenic syndrome. The EMG typically showed small initial motor action potentials which increased by 1200% with high frequency (50 Hz) stimulation of the nerve. The nerve conduction velocities were normal and distal latencies prolonged. The optimal therapy was guanidine hydrochloride at the maximum tolerable dose of 31 m g / k g / d a y in association with prednisone 25 rag/day. Ten months later the patient died. Autopsy of the chest revealed a left parahilar mass of histologically oat-cell carcinoma. 74. Uremic polyneurupathy: clinical and neurophysioiogical results in 115 patients under long-term hemodialytic treatment and in a group of patients after successful renal transplantation. - - C. Pagani, M.C. Gnaita and C. Zoerle (Milan)

We present a clinical and neurophysiological study of .115 patients with chronic renal insufficiency in long-term hemodialysis or in CAPD, staging them in 5 groups of increasing hemodialytic age. Clinical neuropathy was detectable in 37%, but clinical and neurophysiological severity and rate of PNP worsened in the groups of older hemodialytic age. Interestingly, the same group of long-term hemodialyzed patients showed the greatest derangement of both neurophysiological and biochemical parameters (particularly creatinine and PTH). Entrapment neuropathies were detectable only in patients in RDT 82 months (20% CTS). Our data indicate the presence of a prevalently axonal neuropathy, with only mild segmentary demyelination. The role of PTH in the pathogenesis of uremic PNP is still controversial. CAPD seems to delay the onset of PNP. Successful renal transplantation resulted in the total regression of clinical signs and partial regression of electrophysiological PNP, consistent with segmentary remyelination and nerve regeneration. 75. Electrophysiological study of the facial nerve in acoustic tumors. - - G. Pavesi, A. Gandolfi, A. Misk and C. Zini (Parma)

We report preliminary results of a study of the facial nerve in subjects affected by acoustic tumors. Each patient underwent, preoperatively, electroneurography of the facial nerve and evaluation of the blink reflex. The same electrodiagnostic investigations were repeated after surgery at regular intervals. We examined 12 subjects; in 8 cases we found an abnormal blink reflex, while the electroneurogram was altered in 5 patients. The value of the combined use of these techniques is discussed. 76. Diabetic neuropathy: correlation between clinical and dectrophysiological data. - - A. Perretti, R. Nncciotti, B. Lanzillo, D. Francica, R. Veltri, A. Rivellese, A. Palumbo and G. Caruso (Naples)

To evaluate the possible correlation between clinical and electrophysiological data in diabetic neuropathy, 40 patients

61P (22 males and 18 females, age range 21-64 years) with a history of the disease ranging from 10 to 33 years were investigated. The clinical severity of neuropathy was graded and motor and orthodromic sensory conduction velocities were examined along the median, ulnar (motor conduction only) and tibial nerves. Statistical analysis showed that: (a) clinical and electrophysiological sensory impairments constantly started earlier and were more severe than motor impairment; (b) the lower limbs were the most affected; and (c) there was no correlation between the duration of diabetes and the severity of the clinical or electrophysiological disorders. 77. Evaluation of L-carnitine administration on dialysed patients affected by chronic renal failure. - - L. Rocchi, R. Bedini, M. Caivani, S. D'lddio, C. AIfarone and M. FrascareUi (Rome and Pomezia)

The effects of chronic L-carnitine administration were evaluated by EMG analysis on 20 dialysed patients (mean dialytic age 34.7 years) affected by chronic renal failure. No important statistical changes in motor conduction velocity (MCV) or distal latency were found after the treatment, while a reduction of the polyphasic evoked motor potentials was observed. In all patients, an increase of the total muscle power was observed; in 8 cases who, before the treatment, showed an excess of pathological frequencies, the power spectral distribution was within the physiological range after 7 months of L-carnitine administration, These results suggest a myotrophic action of L-carnitine since only favourable changes of the EMG parameters, which demonstrate better muscle fibre functioning, were found. Thus, L-carnitine seems to have a positive influence on the post-dialytic syndrome. 78. Electrophysiological investigation in the stiff-man syndrome. - - B. Rossi, A. Rossi, S. Creta and F. Sartucci (Pisa and Siena)

The following electrophysiological data were observed in a case of stiff-man syndrome. The H / M ratio from triceps surae muscle was 0.73 during cramps of the muscle itself and 0.28 in the relaxed muscle. The silent period of the same muscle H reflex was normal (201.8 msec), as also was the H reflex recovery cycle. Vibration applied to the Achilles tendon (80 Hz, 2 mm amplitude) failed to decrease the amplitude of the H reflex. Vibration of posterior regions of the neck in the standing patient caused the usual postural changes: foreward displacement and compensatory contraction of the triceps surae muscles. The absence of inhibition of the H reflex by vibration of the Achilles tendon could indicate an abnormal presynaptic inhibition of the IA afferents. The increase of muscle stiffness and spasms after sensory stimuli and the increase of cutaneous muscular reflexes previously described in this disorder may indicate a more general involvement of inhibitory interneuronal systems, in spite of the normality of the silent period. It is still uncertain whether the primary dysfunction has a spinal or supraspinal origin.

62P 79. Analysis of later responses (R3) of the trigemino-facial reflex. - - B. Rossi, F. Sartueei, C. Giannini and G. Siciliano (Pisa)

There is some controversy regarding the origin of the third component of the trigemino-facial reflex. In an attempt to throw some light on this problem we evaluated the conduction velocity of the R:-R~ afferent pathways. The delays were 23.9_+4.9 and 11.6_+4.3 msec. The evaluation of threshold showed lower values for R: with respect to R 3. Habituation was maximum for R > intermediate for the second part of R(50-75 msec), absent or minor for the first part (25-50 msec). These data provide some evidence that different reflex pathways are involved in the later components of the trigemino-facial reflex and that only the second part of R~ and especially R~ may be the real nociceptive component. 80. Pneumatic compression during limb surgery, and senso R potentials from musculocutaneous nerve. - - L. Santoro, D. Francica, G. Caruso, U. Passaretti and E.M. Corrado (Naples)

We investigated whether the pneumatic tourniquets generally used to produce a bloodless field during limb surgery cause changes in large myelinated fibres immediately situated beneath the upper and lower edges of the cuff. We measured the conduction velocity along the sensory fibres of the musculocutaneous nerves of both arms in 30 neurologically normal subjects (mean age 31 years) 24 h after they had undergone hand surgery. To exclude that changes could be due to plexus anaesthesia, in 10 normal volunteers the arm was compressed for 60 min by the same pneumatic c u l l rapidly inflated to a pressure of 300 mm Hg, and sensory potentials from musculocutaneous nerve were bilaterally recorded 24 h later. No significant differences were observed in controls or in patients grouped according to age, sex, and the duration and degree of arm compression. The results suggest that clinical changes after blood flow occlusion for limb surgery may depend either on an incorrect compression procedure, or on a particular pressure liability of the patient.

81. Influences of neck receptors on the soleus H reflex. - - S. Traccis, G. Rosati, G. Serra, M. Bissakou, S. Patraskakis and I. Aiello (Sassari)

In this study H reflex testing was used to identify the possible influence of neck afferents on soleus alpha motoneuron excitability. Seven normal adult volunteers were evaluated by' rotating the body while the head was stationary. In each subject, 15 consecutive H reflexes were recorded from the right soleus muscle for each of the following body rotations: 0 ° - 4 ° : 0 ° - 8 ° : 0°-12°: 0°-16 ° in both directions. Our results showed a light facilitation when the body was rotated to the left and a slight inhibition when the body was rotated to the right.

SOCIETY PROCEEDINGS 82. Electrophysiological follow-up on epileptic patients on single drug treatment with carbamazepine. - - S. Traccis, G. Rosati, A. Ticca, G.P. Sechi, A. Demurtas and I. Aiello (Sassari)

In a previous study we reported a mild reduction of both motor and sensory conduction velocities with respect to the controls in 30 epileptic patients on chronic monotherapy with carbamazepine (CBZ) (1-3 years). In the present study conduction velocities were examined in 10 consecutive epileptic patients before and after 1 year treatment with CBZ and in 30 epileptic patients studied 4 years ago. The 30 patients were divided into 3 groups of 10 according to the duration of treatment: (1) 5 year treatment; (2) 6 year treatment and (3) 7 year treatment. By utilizing this more sensitive method we found that all parameters measured remained unchanged during treatment. It is therefore concluded that CBZ given in therapeutic doses does not influence the peripheral nervous system as reflected in measurements of conduction velocities. 83. Effects of intramuscular temperature changes on conduction veloci~ ~of single human muscle fibers. - - W. Troni, M. De Mattei and V. Contegiacomo (Turin)

The effects induced by changing the intramuscular temperature on conduction velocity of single muscle fibers were studied in 15 normal subjects (mean age: 32 _+ 9 years). Conduction velocity in muscle fibers was determined in the short head of the brachial biceps muscle. Cooling was obtained by direct application of ice over a rectangular skin region (12 cm × 6 cm) including the stimulating-recording area. The intramuscular temperature was monitored by means of a needle thermocouple (copper-constantan). In individual subjects the lowest temperature obtained ranged between 18 and 14°C. In all the 24 muscle fibers tested a linear relationship was found between conduction velocity and temperature. The slopes of the regression lines in individual fibers, ranging between 0.08 and 0.19 msec/°C, were positively correlated with the basal (36°C) conduction velocity, ranging between 2.2 and 1.5 msec. The results demonstrate that when the temperature-induced conduction changes are expressed as a percentage of the basal conduction velocity, the mean value of the temperature/conduction velocity coefficient is similar for all the muscle fibers: 3.4% of the basal conduction velocity/°C. 84. Neurophysiological observation in a case of poliomyelitis. - - G. Valli, G. Colturani and G. Scarlato (Milan)

A 29-year-old man affected by acute paralysis of trunk and limb muscles showed serological and cerebrospinal fluid tests positive for poliomyelitis. Four weeks after the onset of the paralysis a motor and sensory conduction impairment was observed, which improved in the following 2 weeks. The case described appears to be demonstrative of the difficulties encountered in an early diagnosis of sporadic poliomyelitis. 85. Paleo- and neocerebellar influence on the spindle activity, of sleep. - - F. Cicirata, A. Scrofani, R. Biondi and M. Cioni (Catania)

Spindle activity (SP) was investigated in 5 subjects with unilateral lesions of the cerebellum. The lesions were older than

ITALIAN EEG SOCIETY, A N N U A L S P R I N G M E E T I N G

63P

6 months in 4 patients and involved both the paleocerebellum and neocerebellum, 2 subjects, respectively. In another subject SA was investigated during functional recovery from an acute paleocerebellar lesion. The results are summarized as follows: lesions of the neocerebellum decreased the SA in both cerebral hemispheres; paleocerebellar lesions decreased SA in the ipsilateral hemisphere, whereas they did not modify SA in the contratateral hemisphere; 7 days after the acute paleocerebellar lesion, there was a strong reduction of SA in the ipsilateral hemisphere, and an increased SA in the contralateral hemisphere; after 30 days SA was again modified on both sides but to a lesser degree: after 80 days the SA returned to presurgical values. 86. Sleep in children with Down's syndrome. - - R.M. Colognola, J.C. Grubar, G.L. Gigli, R. Ferri, S.A. Musumeci and P. Bergonzi (Troina, Rome, and Lille, France) We have studied sleep organization in 8 young institutionalized males with Down's syndrome (DS) (age 8.11 + 2 years); 3 of them were severely retarded and 5 moderately retarded; 17 age-matched normal subjects were used as a control group. The ratio between high frequency and low frequency eye movements (R = l < l s / I s > 2s) was calculated as a possible index of 'organization.' The most important findings were: (1) a reduction in the percentage of REM sleep in DS subjects: (2) a lengthening of the latency of the first R E M period in DS subjects; (3) an increase in the percentage of undifferentiated sleep in DS. Lastly 3 out of 8 DS subjects presented concomitance of sleep spindles and R E M s during Sz and during REM sleep. 87. Sleep patterns and dreams in patients with focal cerebral lesions. - - L. Murri, R. Mas~tani, L. Giovanditti, G. Siciliano, R. Arena and A. Muratorio (Pisa) In a previous study we observed that patients with focal cerebral lesions in posterior areas frequently reported loss of dream recall. These results were obtained using a questionnaire compiled every morning on awakening. In order to evaluate whether dream recall is related to differences in the sleep pattern between the two groups, 7 patients with posterior and 5 with anterior lesions were studied. No significant variations in either the sleep pattern or the length of the REM sleep period were observed. During R E M sleep awakenings, it was observed that all patients with anterior lesions reported dreams, while 5 of the 7 with posterior lesions said that they had not dreamed. In conclusion, the presence or absence of dream recall in patients with posterior lesions in an acute stage does not seem to depend on variations in the sleep pattern. 88. Breathing disturbances during sleep in the elderly. I Silvestri and R. Di Perri (Messina)

L.

Sleep may be considered as one of the principal biological markers of aging. Respiration is one of the most important

factors in this biological process. In fact, elderly people are generally subject to a great amount of sleep fragmentation, which is closely related to central episodes of apnea. This physiological phenomenon can become so relevant that it should be considered a real central apnea syndrome. However, the most dangerous pathology occurring in this age group is obstructive apnea, which often leads to important oxygen desaturation and relevant hemodynamic changes. Also, females with the loss of their progesterone protection are subject to this kind of disorder. It is interesting to investigate the role of benzodiazepines which are often administered to cure a decrease in TST, especially to evaluate the risk to elderly COPD patients. In our study we evaluated nocturnal polygraphic records and ventilatory responses before and after flurazepam administration in a group of patients with moderate to severe COPD. We found that 2 patients presenting important O 2 desaturation during R E M sleep, both spontaneously and after a single dose of flurazepam, showed a rather relevant diminution of their waking hypoxic drive to ventilation after 1 week on flurazepam 15 mg daily. 89. Cyclic alternating pattern (CAP) sequences in normal nonREM sleep. - - M.G. Terzano, D. Mancia, G. CostanL M.R. SalatL L. Parrino, A. Decembrino and M. Marchini (Parma) The cyclic alternating pattern (CAP) is a kind of periodic activity consisting of two alternating stereotyped EEG patterns which are quite distinct from each other. Its clinical significance has so far been greatest in the diagnosis of stage 2 coma and Creutzfeldt-Jakob disease. This EEG pattern also appears during physiological sleep, in which CAP represents a specific entity of non-REM sleep. A total of 2381 CAPs were recorded in 20 sleep traces of normal subjects. The average duration of the cycle was about 40 sec and it was present in about 23% of n o n - R E M sleep. The CAPs were grouped in 328 sequences. which lasted from 30 sec to 29 min. The appearance of CAP sequences was closely associated in time with the occurrence of some dynamic events during sleep, i.e., with 90% of the fallingasleep phases, with 77% of the phases during which non-REM sleep gives way to REM sleep, with 74% of the changing phases within non-REM sleep, and with 73% of the microarousal phases. Only 1% of the REM sleep phases turning into nonR E M sleep were associated with the appearance of a CAP sequence. 90. Clinical and polygraphic aspects of a case of parasomnia. - M.G. Arena, R. Silvestri, R. Ciliberto, C. Ruello and R. Di Perri (Messina) Data are reported on a 12-year-old girl who presented, during nocturnal physiological sleep, frequent episodes, lasting 30 sec-2 rain 30 sec, characterized by violent movements of the right arm rhythmically striking her head. These episodes occurred several times a night since birth. The movements always occurred during stage 2 non-REM sleep, without causing any

64P arousal or any change in the sleep stage. Different kinds of automatisms, namely chewing and scratching, often interspersed the patient's sleep, in stages 1, 2 and 3. Waking and sleep EEGs and the neurological examination were normal. This case is compared with cases described as nocturnal paroxysmal dystonia. 91. The Marinesco-Sjogren syndrome: polygraphic study of nocturnal sleep. - - P. Bramanti, R.M. Ricci, M. Benedetto, S. Cuzzocrea, S. Bagala and R. Di Perri (Messina)

Three members of a family (father and 2 sons) affected by Marinesco-Sjogren disease have been the object of a clinical and electrophysiological study. We report here the results obtained on a polygraphic study of their nocturnal physiological sleep. The diagnosis of Marinesco-Sjogren disease was based on cataract, cerebellar ataxia, mental deficiency, myoclonus and skeletal malformations, which were present in all the patients. The following results were obtained: (1) normal wakefulness and sleep EEG activity; (2) normal distribution of sleep stages except for 1 patient who showed total absence of stage 3 and 4 sleep; (3) normal distribution of sleep cycles; (4) persistence of myoclonus in all stages, REM included; (5) no respiratory dysfunctions; (6) no alteration of cardiac frequency; (7) pre-eminence of generalized muscular hypotonia in all sleep stages. 92. Epileptic seizures in cerebro-vascular disorders: clinical and EEG correlations. - - P. Bramanti, M.A. Coraci, M.L. Roberto, M. Gugliotta and R. Di Perri (Messina)

The occurrence of epileptic fits in patients affected by stroke and hospitalized in the Neurological Institute of the University of Messina during the years 1979-1983 was investigated. Out of a total of 4225 patients, 888 (21%) were affected by acute cerebro-vascular disorders and among these only 34 (3.82%) suffered from epileptic fits, the great majority in strict correlation with the ictal event. Seizures were generalized in 8 subjects (23.5%), and partial in 26 (76.5%): elementary in 16 patients, complex in 4 and secondarily generalized in 6. The EEG showed: normal findings in 10 cases, focal slow abnormalities in 14 subjects, focal slow and sharp waves in 2 patients, bilateral slow waves in 4, bilateral spikes in 1 and focal spikes and waves in 3. Neuroradiological investigations showed signs of cerebral hemorrhage in 7% of the cases. 93. Interference by imipramine in nocturnal enuresis. - - M. Meduri, M. Deodato, G. Arena, C. Alafaci, C. Ruello and D. D'Amico (Messina)

Six enuretic subjects were treated with imipramine in a single dose of 1.5 m g / k g per os before going to sleep. A urodynamic evaluation was carried out before the treatment and after 15 days, employing the following tests: (a) number of daily voidings; (b) average urine volume; (c) volume of voluntarily deferred voiding; (d) volume of spontaneous voiding during sleep (enuretic event); (e) cystometry in wakefulness and sleep.

SOCIETY PROCEEDINGS After treatment, 5 patients out of 6 were free from any enuretic event over a span of 2-3 days. The treatment did not induce significant changes in urodynamic parameters in any subject. These results seem to exclude that imipramine exerts its therapeutic effect on nocturnal enuresis by retention of urine. In addition, the rapidity of obtaining the therapeutic effects seems to exclude the hypothesis of a psychotropic mechanism. On the other hand, imipramine couKt influence the awaking threshold to afferents from the bladder. 94. Urodynamic evaluation in nocturnal enuretic subjects. - M. Meduri, M. Deodato, G. Arena, C. Alafaci, R. Silvestri, C. Ruello and D. D'Amico (Messina)

Thirteen subjects affected by nocturnal enuresis aged from 9 to 18 years and 5 controls underwent the following urodynamic evaluation: (a) number of daily voidings; (b) average urine volume; (c) volume of a voluntarily deferred voiding; (d) volume of spontaneous voiding during night sleep (enuretic event); (e) cystometry during wakefulness and sleep. In all the examined subjects the volume of the voluntarily deferred voidings and the cystometry volumes in wakefulness corresponded to the values of controls. During sleep the bladder filling, either spontaneous or artificially induced, able to induce the enuretic event was similar to the bladder filling values producing wakefulness in controls. In 5 subjects the following features were observed: (a) more frequent daily voidings; (b) reduced urine volume of each voiding; (c) onset of inhibited contractions during cystometry even at a small filling. The results show that 30% of our enuretic subjects suffered from a bladder condition definable as 'destrusor facilitation' which effects neither the voluntarily deferred bladder capacity nor the enuretic event. 95. Sleep pattern in Eaton-Lambert syndrome. - - G. Mennuni, M. Morante, C. Casali, C. Scoppetta and P. Bergonzi (Rome)

The sleep pattern in the Eaton-Lambert syndrome (ELS) has been studied. Two patients, a 58-year-old female and a 56-year-old male, affected by chronic ELS without malignancy slept in the laboratory for 3 consecutive nights (1 adaptation plus 2 recording nights). In comparison with normal control subjects matched for sex and age both patients showed sleep abnormalities. In particular, total sleep time, sleep efficiency index and stage II sleep were reduced, while sleep latency, number of stage shifts, interspersed wakefulness and stage I sleep were increased. 96. Sleep spindles in unilateral extrapyramidal disorders. - F.M. Puca, M.G. Minervini, M. Savarese, C. De Marzo and C. Lanave (Bari)

Previous studies indicated an involvement of sleep spindling in extrapyramidal diseases with an increase of spindle activity in patients affected by parkinsonism, Fahr's disease and Wil-

I T A L I A N EEG SOCIETY, A N N U A L S P R I N G M E E T I N G son's disease, and a reduction in patients with chronic chorea and athetoid dystonias; after therapy, the patients who showed a marked clinical improvement developed also a normal spindle activity. In unilateral extrapyramidal disorders data concerning a possible interhemisphefic asymmetry in sleep spindles are scarce and inconclusive. Therefore we examined spindle activity in patients with hemiparkinsonism, hemichorea and hemiballismus in basal conditions and after the therapy-induced clinical improvement. The characteristics of sleep spindles were studied by an automated analysis system. Our data showed a significant asymmetry in spindle activity between the two hemispheres in basal conditions. This asymmetry disappeared after the clinical improvement. Particularly in hemiparkinsonism the spindle activity appeared much lower in the affected hemisphere and this difference disappeared after the administration of L-DOPA or bromocriptine. These observations indicate that dopaminergic pathways m a y be involved in the production of cortical spindling and cast further light on the role of basal ganglia so far as sleep spindling is concerned. 97. Epilepsy with occipital spike-wave complexes. - - L.G. Bongiovanni, A. Polo, G. Coccia, L. Rozza, O. Arancio, A. Pomes, C. Cattaino, A. Fiaschi and D. De Grandis (Verona and Pordenone) We studied clinical and EEG features in 10 patients with occipital spike-wave complexes, suppressed by eye opening and evoked by the abolition of central vision. The hallmark of these selected subjects was the lack of neuropsychological, neuroradiological and ophthalmological abnormalities. The spike-wave complexes were usually rhythmic, unilateral in 6 cases and bilateral in the others (asynchronous or synchronous with asymmetrical amplitude). Focal visual symptoms, referred by 6 patients, were associated with migrainous p h e n o m e n a in three of them. In all these 6 cases the response to therapy was poor. The VEPs obtained with structured and unstructured stimuli were symmetrical. Of the other 4 children with bilateral occipital paroxysms and generalized seizures, three had only sporadic seizures with good response to treatment. They showed, moreover, asymmetrical VEPs and, sometimes, rolandic spikes. The different patterns of the clinical and electrophysiological features may be related to different pathogenic mechanisms. 98. Secondary bilateral synchrony (SBC): anatomical, clinical and EEG correlations. - - H. Gastaut, A. Magandda and E. Mariani (Marseilles, France, Messina and Milan) Thirty-three cases of organic partial epilepsy with secondary bilateral synchrony were examined. Thirteen out of the 33 had familial antecedents of epilepsy or febrile convulsions. Most of the cerebral lesions were the result of traumatic or vascular accidents, some were caused by an inflammatory pathology of the medial or anterior part of the damaged hemisphere. EEG abnormalities consisted of generalized slow wave discharges, associated in 91% with focal spikes and waves in the damaged hemisphere. Ictal events are represented by

65P elementary or complex partial seizures often secondarily generalized, or generalized or hemigeneralized seizures from the onset. The results of treatment were good in 78%, bad in 15%, slight in 6%. In 13 cases (40%) no neurological or psychological abnormalities were present. In 20 (60%) mental retardation, associated in 9 cases with hemiplegia, and in 1 with tetraplegia, was observed. The high incidence of familial antecedents of epilepsy or febrile convulsions supports the hypothesis that familial epileptogenic predisposition can be determinant in the genesis of SBS. This kind of partial epilepsy differs from the LennoxGastaut type of secondary generalized epilepsy in ictal and interictal semeiology and in the better prognosis. 99. Computerized EEG in the elderly. - - S. Giaquinto and G. Nolle (Naples) The aim of this investigation was to quantify EEG findings from different areas of the scalp and t o identify regional differences in the power spectrum. The research was carried out on 47 healthy volunteers (mean age 71 _+5 years), 32 men and 15 women. The signal was analysed by means of spectral density function. Relative activity, mean frequency and coefficient of asymmetry were calculated for each of the 5 bands: delta, theta, alpha, beta 1, beta 2. T h e m e a n alpha frequency was: 9 . 0 7 - 9 . 1 6 - 9 . 2 6 ; 9.07-9.15-9.29 Hz, respectively. Mean delta and theta frequencies were also higher in the posterior leads. The opposite was true for the beta bands. The relative activity also showed regional differences: beta activity was prevalent in frontal leads, whereas alpha activity was prevalent in occipital leads. Sex related differences were found. The relative delta activity was higher in males with a lower relative beta activity and a lower mean alpha frequency. It is concluded that normal aging does not seriously impair EEG organization. 100. Focal tonic facial hemispasm related to partial continuous epilepsy. - - M. Meduri, P. Girlanda, R. Musolino, C. Alafaci and P. De Domenico (Messina) A woman who episodically presented motor seizures affecting the left limbs complained of persistent tonic contraction of some left mimic muscles. EEG examinations in an interictal period showed sporadic low-voltage spikes in the right parietotemporal region. The tonic contraction of the mimic muscles disappeared only during sleep and did not change when the EEG pattern varied. An EEG recording during a seizure, tonic then clonic jerking of the left limbs with sparing of the face muscles, showed spikes together with slow waves in all leads. With regard to the blink reflex a depression of the left side R 2 responses independent of the side of stimulation was found. Electrophysiological findings showed that the focal tonic spasm of mimic muscles was due to a supranuclear and probably cortical pathology. A diagnosis of Bancaud's first type partial continuous epilepsy was made and the peculiar feature of a tonic instead of clonic muscular contraction is stressed.

66P 101. Sleep deprivation: usefulness and limits. - - C. Pagni, G. Orsini and D. Giuccioli (Milan)

The effects of sleep deprivation (SD) were investigated in 318 patients (mean age 23.7 years; range 19 months-66 years): 119 with epileptic seizures (often the first fit) and 199 with other neurological non-epileptic disorders. All patients had normal or non-specific waking EEGs. After SD 32% and 16.1%. respectively, of the patients with and without epileptic seizures had epileptiform abnormalities ( P < 0.001) and there were 21% of false positives among the patients with cranial trauma and headache: SD is not strictly specific for epilepsy. Moreover. there were 68% of false negatives. SD is more effective in young than in old patients with epileptic seizures (41% vs. 14.6% of epileptiform abnormalities: P < 0.01). False positives do not decrease with age in non-epileptic patients (15.4% and 14.5%, respectively in young and old patients). Photoparoxysmal responses were slightly greater after SD. The percentage of physiological photic driving (PD) significantly decreased ( P < 0.005) after SD in both groups of patients, partly because PD probably spontaneously diminishes in the subsequent EEGs, after any 'activating' acute neurological event; partly because SD, by decreasing vigilance levels. probably inhibits PD. 102. 3-D biomagnetic localization of epileptic interictal activity in cases of focal epilepsy. - - G.B. Ricci, I. Modena, R. Leoni, G.L. Romani, F. Campitelli and S. Buonomo (Rome)

We have previously shown that when there is a good correlation with the corresponding electrical signal, MEG provides a 3-D localization of the spikes and of other interictal activity in cases of focal epilepsy. To check the validity of the method we have examined patients suffering from focal epilepsies with localization determined by the symptomatology, in most instances confirmed by radiological examinations (CT etc.) and in a few cases by operative findings. This investigation has confirmed the validity of the method and its clinical usefulness. At present the method is hampered by the use of only one sensor, by the background noise of the instrument, and by the fact that the spherical model does not always correspond with the head because of an unfavourable orientation of the source. However, technical and methodological advances are being made (use of polysensors, increased sensitivity, improved anatomical models), and the unfavourable orientation of the biomagnetic signal can be overcome by the simultaneous measurement of the bioelectric signal. 103. Tumoral epilepsy or cerebral tumor in epileptic patients. - - J. Roger, A. Magudda and M. Bureau (Marseilles, France, and Messina)

Four cases of different kinds of cerebral tumor diagnosed in epileptic patients long after the onset of epileptic seizures are reported. The age at the first ictal event, the clinical features of seizures, their good responsiveness to treatment and the EEG abnormalities indicate that in these subjects, epilepsy could be independent of the tumors.

SOCIETY PROCEEDINGS A comparison of two contemporary epidemiologic studies in Rochester regarding epilepsy and brain tumors suggests that a fortuitous association of epilepsy and tumors may be more frequent than appears. Moreover~ the rarity of this occurrence could be related to the lower incidence of various kinds of tumors in chronically treated epileptics than in normal subjects. 104. Antiepileptic drug withdrawal: EEG findings in 83 patients. - - P. Tinuper, A. Baruzzi, G. Procaccianti, A. Serracchioli and E. Lugaresi (Bologna)

Eighty-three patients (28 primary generalized epilepsies, 31 partial epilepsies, 12 rolandic spike epilepsies and 12 miscellanea), aged 8-67 years, seizure-free for almost 2 years, started withdrawal of antiepileptic drugs. Drug doses were reduced by a quarter every 3 months. Each patient had a clinical and EEG evaluation at every step during reduction and 3 and 12 months after complete withdrawal of the drugs. EEG tracings of each patient were blindly and sequentially evaluated by the same neurologist, in the same session at the end of the follow-up. Each record was considered as pathological if it presented truly epileptic features (sharp waves, spikes, polyspikes or spikeand-wave complexes). Twenty-eight patients relapsed (28 PGE, 31 PE and 4 with other epilepsies). The following considerations are presented: (1) initial tracing, either normal or pathological, is not predictive of relapses (35 and 31% respectively); (2) patients whose EEG improved or remained unchanged had the least rate of relapses (19%), whereas those whose EEG worsened had the poorest prognosis (63%). 105. Effects of antiepUeptic drug withdrawal on the occurrence of seizures. - - M.G. Marciani, J. Gotman, F. Andermann, A. Olivier, P. GIoor, L. Quesney and A. Sherwin (Rome, and Montreal, Canada)

Thirty-nine epileptic patients, candidates for surgical treatment, were studied with scalp and sphenoidal or with chronic intracerebral electrodes to determine the localization of their focus. Patients, after routine EEGs on full medication, had EEGs recorded by 16-channel cable telemetry at the time of antiepileptic drug withdrawal and for 1-2 weeks following withdrawal. We investigated the pattern of occurrence of secondarily generalized and partial seizures. Twenty-six of 39 patients had an increase in generalized seizures. In 77% of these patients the increase occurred in clusters which were not usually followed by further seizures; most of the clusters occurred between 1 and 4 half-lives of the drug withdrawn. Of all drugs, the withdrawal of carbamazepine was that which was followed by the largest number of clusters of seizures. Diphenylhydantoin withdrawal was usually followed by a single seizure. Twenty-seven of 39 patients showed an increase in partial seizures which was usually long lasting. These results show fhat the sudden increase of generalized seizures is a transient event of short duration related to the abrupt change of medication. The long lasting increase in partial seizures appears influenced by both the withdrawal and the reduced low level of medication.

ITALIAN BEG SOCIETY, A N N U A L S P R I N G M E E T I N G 106. Asymmetrical pupillary dilatation during focal seizures: role of prefrontal cortex. - - V. Agnetti, A. Ganga, P. Loffredo, M. Tondi and S. Traccis (Sassari) Symmetrical dilatation of the pupils may occur in any type of epileptic seizure. Clinical observations of unilateral mydriasis during or immediately after seizures have been reported in a few cases. The case we present is the first one in which asymmetrical pupillary dilatation is documented during ictal EEG recording and in which it is related to the CT lesion site. P.O.. a 13-year-old boy, developed clusters of simple partial seizures 1.5 months before hospital admission. These seizures started with an asymmetrical (wider on the right) dilatation of the pupils, followed 5 - 1 0 sec later by tonic deviation of the eyes to the right. Four EEG recorded seizures showed a left fronto-temporal spike activity strictly correlated with the appearance of the mydriasis. An area of increased attenuation including cortex and underlying white matter in the left prefrontal region was recognized on the CT scan. These and previous findings suggest that unilateral or asymmetrical pupillary dilatation is indicative of an epileptogenic focus involving the second and possibly third frontal convolution, contralateral to the mydriasis. Experimental stimulation in the frontal eye field elicited similar results in animals and humans. 107. The 'flick to flick' response to slow frequency intermittent photic stimulation. - - U. Aguglia, G. Farnarier, J. SalasPuig, P. Tinuper, R. Ferrara. P. Santanelli and A. Quattrone (Catanzaro, Bologna, and Marseilles, France) Intermittent photic stimulation at low frequency may induce: (1) an occipital positive deflection (OPD) followed by 'photic driving' (OPD + PD); (2) an O P D not followed by PD (so-called 'flick-to-flick response:' FTFR). Clinical and EEGraphic data have been examined in 108 subjects with O P D + P D and in 87 subjects with FTFR. Significant differences in age distribution and in electro-clinical data have been found between the two groups. It is suggested that the F T F R may indicate a diffuse encephalopathy, particularly in childhood and in old age. 108. Effectiveness of clobazam in startle-induced epileptic seizures. - - U. Aguglia, P. Tinuper and H. Gastaut (Catanzaro, Bologna, and Marseilles, France) The present study was undertaken to clarify the possible therapeutic activity of benzodiazepines in the so-called 'startleinduced epileptic seizures.' A benzodiazepine was associated with the previous antiepileptic treatment in 16 ineffectively treated patients suffering from startle epilepsy. Clonazepam was administered to 3 patients: 1 of them was completely unresponsive and 2 became seizure free for a mean of 16.5 months, but they complained of drowsiness or ataxia. Clobazam was administered to 13 patients: 15.4% of them were completely unresponsive, 23.1% experienced a drug resistance and 61.5% obtained a good control (91.5% reduction of the

67P reflex seizures) for a mean of 22.75 months. In spite of a possible loss of therapeutic activity, the appearance of very few unfavourable side effects and the presence of favourable side effects ('psychomotor arousal') makes clobazam therapy important in the treatment of patients suffering from startle epilepsy. 109. lsoelectric EEG during massive haemorrhage: clinical and neuroreanimatury aspects of a case. - - P. Bassi, C. Tnnini, S. Sbrascini and A. De Gasperi (Milan) We report the case of a 56-year-old man who, during recanalization of the innominate artery, had a heavy haemorrhage owing to laceration of the arterial wall. A dramatic pressure fall ensued and concomitantly there was a progressive slowing of rhythm and a subsequent loss of bioelectrical activity in the EEG. We immediately administered a barbiturate bolus intravenously and there was a gradual rise of arterial pressure with a resumption of electrical activity, which returned to normal conditions after 239 sec. On waking, the patient showed no loss whatsoever of his mental and molor functions. Therefore, a completely isoelectric EEG, lasting several minutes, is not always a sign of irreversible damage of brain tissue. Moreover, suitable and timely reanimatory steps, particularly pharmacological ones, play a fundamental role in reducing neurological complications and therefore in assuring a favourable prognosis in the cases of surgical risk. 110. Effects of gammaglobulin treatment on epileptogenic encephalopathies. - - R. Bedini, M.R. De Fen, A. Orano, L. Rocchi and B. Scarpati (Rome) The effects of gammaglobulin therapy have been studied from a clinical, immunological and electrographic viewpoint, in 10 children affected by epileptogenic encephalopathies. After the injection of high doses of IgG, an appreciable reduction of the seizure frequency and an improvement of the behavioral and psychological performances have been observed in 7 children. These clinical modifications were not correlated with a decrease of the EEG epileptic elements, but in most cases they were associated with an increase of the alpha activity a n d / o r an increase of power of the predominant EEG frequency. No remarkable modifications of either the immunological data or the plasma levels of antiepileptic drugs were found to accompany the clinical and EEG changes. !11. The efficacy of monotherapy in new untreated patients with epilepsy. A prospective study. - - M.D. Benedetli, L.G. Bongiovanni, G. Coccia, A. Fiaschi and L. Rossa (Verona) In a prospective study, 22 new patients with epilepsy, previously untreated, were treated with monotherapy. Fifteen patients with phenobarbital (PB) (8 grand real and 7 simple partial seizures), 4 with carbamazepine (CBZ) (2 complex partial. 1 simple partial and 1 grand mal seizures), and 3 patients

68P (grand mal) with diphenylhydantoin (DPH). The patients were followed up for a mean of 18.7 months. Seizures were completely controlled in 18 patients; the monotherapy failed in 2 patients. Two other patients had a reduction in seizures. The control was better in grand mal than in partial seizures. The success of treatment with a single anticonvulsant drug was probably related to application of therapy early in the history of epilepsy. 112. The effects of acute administration of viloxazine on 1LS: preliminary report. - - M.C. Narbone, P. Bramanti, F. Pisani, R.M. Ricci, S. Serra, M. Benedetto, C. Alafaci and R. Di Perri (Messina)

The effect of viloxazine on the photoconvulsive response was tested in 5 subjects (4 epileptics and 1 healthy volunteer) showing a constant EEG response to photic stimulation (ILS). After viloxazine administration (single oral doses of 2.6 mg/kg), the latency to ILS was modified in the epileptics (reduced in 2 patients and increased in the remaining 2), while it was unchanged in the normal subject. The other parameter examined, namely the self-sustained activity, did not show any appreciable modification. Although these findings are preliminary and even conflicting, they suggest that viloxazine may exert some effect on ILS. 113. Confusional state with periodic EEG activity (PLEDs) in a patient with cerebral metastases. - - G. Caso, R.M. Cuomo, V. Rosanova, A. Gargiulo, G. Salomone and M. Lambiase (Castellammare di Stabia)

A case of epilepsy characterized by a confusional state and by lateralized, periodic epileptic discharges is described. A 65-year-old male was hospitalized because of a state of confusion and automatic gestures that had started 24 h previously. The neurological examination on admittance excluded focal deficits. The EEG showed periodic activity localized to the right hemisphere, which was characterized by 150-200 mV biphasic or triphasic sharp waves, with a repetitive stereotyped morphology, interrupted by 1 sec pauses. The clinical symptoms and EEG did not respond to the intravenous administration of 10 mg of diazepam, and treatment with 150 m g / d a y phenobarbital was initiated. Clinical symptoms and abnormal EEG findings disappeared after 5 days. Computerized tomography revealed 2 cerebral metastases, one on the convexity of the left rolandic area, and one in the fight temporal region. A bronchogenic pulmonary cancer was diagnosed. 114. ClinicaI-EEG evolution of a case of subacute sclerosing panencephalitis (SSPE) treated with plasma exchange, araC and cyclophosphamide. - - D. Cocito, L. Durelli and M. Delsedime (Turin)

It has been suggested that combined therapy be used to treat SSPE. Therapy should aim at removing circulating immunocomplexes that inhibit cellular immunity, and at prevent-

SOCIETY PROCEEDINGS ing viral replication and antibody resynthesis. We therefore treated a case of SSPE with the association of plasma exchange, ara-C and cyclophosphamide. Seven exchanges of a plasma volume corresponding to 5% of body weight, 100 rag/day of intravenous ara-C, and 500 m g / d a y of intravenous cyclophosphamide were given over a 15 day period. No significant clinical-EEG improvement was obtained and the treatment had to be stopped because of the occurrence of severe side effects: hemorrhagic cystitis and pancytopenia. 115. Lisencephaly syndrome (agyria, pachigyria): electroclinical and neuroradiological study o[ 11 cases. - - V. Colamaria, E. Trevisan, C. Chiamenti, N. Rizzuto, A. Simonati, G. Capizzi, A. Peloso, P. Drigo, A.M. Laverda, P. Casara, M. Recla and B. Dalla Bernardina (Verona, Turin and Padua)

Lisencephaly is a rare congenital brain anomaly (caused by arrested neuronal migration) characterized by a lack of cerebral sulcus formation. It ranges from complete agyria to pachigyria, microencephaly with large ventricles (colpocephaly) and subcortical heterotopias. A clinical-EEG-radiological report is given on 11 cases of lisencephaly. The most important features in our cases were: persistent hypotonia (decerebrate posture never observed); monomorphous fits (focal or tonic seizures) in all patients; high voltage of electrical activity associated with pathological fast interictal beta activity with unusual topography (temporo-parieto-occipital localization). This condition can now be diagnosed during life: computed tomographic findings are widened subarachnoid space, smooth surface of the brain, enlarged ventricles, lack of insular opercularization, and decreased density of the periventricular white matter. The sex distribution in our cases was 7 girls and 4 boys. In 1 boy, lisencephaly is part of a complex cerebro-oculo-muscular syndrome. The etiology is unknown in 5 cases, and genetic in 2. In 4 subjects this brain malformation was the result of a fetal viral infection (rubella: 2 cases, and cytomegalovirus infection: 2 cases). 116. A case of asterixis in the course of antiepUeptic treatment and phenobarbital intoxication. - - G. Costani, A. Decembrino, M.R. Salati, I. Parrino and D. Visintini (Parma and Vincenza)

In a 52-year-old patient complaining of complex partial seizures, a therapy with phenobarbital, carbamazepine and diphenylhydantoin, suddenly produced asterixis, dysarthria and ataxia. On admission, polygraphy displayed asterixis. The dosage of carbamazepine was reduced and, 3 days later, the neurological examination was normal. Serum anticonvulsant levels, however, showed carbamazepine and diphenylhydantoin within normal range, while phenobarbital was increased. Nevertheless, the decreased carbamazepine dose resulted in clinical improvement and, at the same time, the phenobarbital serum level was decreased.

I T A L I A N EEG SOCIETY, A N N U A L S P R I N G M E E T I N G 117. A non-evolving encephalopathy with myoclonus and epilepsy: back-averaging of the EEG activity preceding myoclonic jerks. - - S. Cusumano and P.G. Bardin (Treviso) The case of a 21-year-old woman with a clinical picture of spastic tetraparetic encephalopathy: generalized, bilaterally synchronous, arrhythmic, repetitive myoclonic jerks and grand mal epileptic attacks, is described. These symptoms first appeared when she was 7 years old, after an acute disease interpreted as meningoencephalitis; they then stabilized without any further enhancement. The drugs which control her epileptic seizures do not affect the myoclonic contractions. On the other hand, the contractions are not correlated with any EEG sign. Back-averaging of EEG signals showed 3 peaks preceding myoclonic activity. Mean latencies were 75, 51 and 22 msec and mean amplitudes 17, 11 and 2 ~V from the proximal muscles of the upper limb. All latencies were increased by about 12 msec compared with those of the lower limb. Amplitudes increased slightly in the central regions of the scalp but morphology and latencies did not vary anywhere. Phase inversion of the 3 peaks occurred when recording from the cervical level. 118. Repeated absence status in girls: a particular form of primary generalized epilepsy. - - B. Dalla Bernardina, G. Medico, E. Trevisan, C. Chiamenti, G. Capovilla, V. Colamaria, G. Andrighetto and N. Diroma (Verona) This study concerns 14 neurologically normal girls who suffered from a particular epilepsy characterized solely by repeated absence status appearing at a mean age of 4 years 8 months. In 9 cases familial antecedents of epilepsy or febrile convulsions were present; 10 subjects presented one or more febrile convulsions before the status. The status is characterized by loss of contact, lack of speech, absence of motor manifestations, lasting from 20 min to 2 h. The girls stay still but can often walk if accompanied; in some cases there is repeated vomiting. Invariably, the attack is followed by sleep and amnesia for the episode. On the interictal EEG brief discharges of subclinical generalized spikes and waves (s-w) are present when awake or asleep. Some discharges of 3 / s e c generalized s-w appeared in 8 cases, being clinically evident only in 3 cases. The status, recorded in 2 cases, is characterized by a continuous discharge of ample and slow s-w involving synchronously both hemispheres in the fronto-centro-temporal regions, promptly stopped by benzodiazepine i.v. This status recurs in subjects untreated or treated with CBZ or DPH, but never in cases treated with PB or DPA. 119. Continuous EEG monitoring in 2 cases of post-traumatic coma with borderline EEG pattern. - - G. De Luca, P. Conti and R. Conti (Florence) We describe 2 cases of serious post-traumatic coma, with clinical signs of brain-stem pain, which underwent continuous E E G monitoring with spectral analysis. In one case the pain

69P was caused by an interpeduncular haematoma, and in the other by a transtentorial hernia due to a brain contusion in the left temporo-frontal area, associated with a limited subdural haematoma. In both cases borderline EEG revealed a main 8 Hz component. The EEG in the case of interpeduncular h a e m a t o m a was symmetrical on the two hemispheres and slow and fast components of variable amplitude and frequency were recorded. The case of transtentorial herniation showed interhemispheric asymmetry due to a marked reduction in amplitude of the left hemisphere tracings and higher fast components in the right hemisphere. Symmetric theta-delta components with a fairly good amplitude, and epileptic seizures, particularly evident in the left hemisphere, were also observed. The patient with a left temporo-frontal haemorrhagic contusion died, while the other patient was discharged from hospital 2 months after the trauma with slight neurological deficits. 120. Cat-scratch disease with encephalopathy: report of a case. - - A.E. Di Rosa, G. Gallitto, L. Morgante, M.A. Coraci, M.C. Fazio, M. Gugliotta and R. Di Perri (Messina) A 13-year-old boy was scratched on the right arm by a cat. A few days later he showed lymphoglandular swellings in the right epitrochlear region, pustules in the thenar eminence of the right hand, and fever. In spite of prompt ampicillin therapy a prolonged state of coma followed a generalized tonic-clonic fit. Neurological examination was characterized by light coma with neck rigidity, mydriasis, increased tendon reflexes, bilateral Babinski. Routine laboratory data were within normal range except for the Katz index, and a slight increase in CSF proteins. The EEG pattern was characterized by diffuse and symmetric slow waves. Cerebral CT scan was negative. Tests for typhoid and paratyphoid A, B and C, toxoplasmosis, brucellosis, mononucleosis, tuberculosis and syphilis were negative. He was treated with betamethasone and 3 days later the patient became alert and responsive. A neurological examination was negative, while EEG tracings showed a slow progressive improvement. A normal EEG pattern was observed only 5 weeks later. 121. A 24 h monitoring system for the diagnosis and therapeutic follow-up of epilepsy. - - M. Francinetty Bressy and G. Garino (Turin) EEG signals were recorded using HDX-82 preamplifiers connected to bipolar collodion electrodes according to the international system. Recording: T D K cassette AD120 with an Oxford 4-Channel Medilog recorder. Visual monitoring: Page Mode Display, Oxford Medical System. Twenty patients were investigated: 10 with epilepsy with serum levels in the therapeutic range; 10 not undergoing anticonvulsant drug treatment, with one or more previous blackout episodes and negative traditional EEG. First group: In some cases a number of subjective signs were not found on EEG, while in others we found a marked contrast between subjective condition (satisfactory, due to the absence of seizures) and EEG recording of frequent discharges.

70P Second alized). The clinical change

SOCIETY P R O C E E D I N G S group: 4 EEG alterations were found (3 focal, 1 generSix tracings were normal. findings have been useful in the diagnosis of some problems, while in others they have prompted us to treatment or to investigate the patient further.

122. Antiepileptic drug plasma levels and side effects. - - S. Gentile, L. Pinessi, D. Leotta, L. Tarenzi and V. Tassi (Turin) Neuropsychiatric, haematological, cutaneous, digestive, endocrinological and metabolic toxic side effects have been described during antiepileptic treatment. We have investigated for a correlation between plasma levels of antiepileptic drugs and the onset of side effects. Seventy-seven epileptic patients were selected from patients who showed one or more iatrogenic toxic effects during antiepileptic pharmacological treatment. Plasma levels of antiepileptic drugs were measured. Two groups clearly emerged: the first (]4 patients) with pharmacological side effects clinically manifest, and the second (43 patients) without pathological signs or symptoms, but characterized by subjective disorders only. In the first group there were 10 patients with g u m hypertrophy, 1 with baldness, 10 with cerebellar symptoms and 6 with dysplopia. In the second group, 17 patients showed sleepiness, 5 vertigo, 4 depressed sexual drive, 3 headache. In 14 patients more than one of these symptoms coexisted, A positive correlation was found between increased plasma levels of antiepileptic drugs and objective clinical symptoms: in the first group 73.5% of patients showed toxic plasma concentrations. In the second group, no correlations were found. Our data confirm the usefulness of antiepi[eptic drug monitoring in the prevention of toxic side effects. 123. EEG spectral analysis in a case of post-traumatic alpha coma. - - C. Lacomba, T. Fiore, F. Simone, R. Santostasi and E. Sfoorza (Bari) A patient with a post-traumatic alpha coma was monitored for 76 h by compressed spectral array (CSA), starting from the 40th h of hospitalization until death. Two conventional EEG control recordings were carried out. Initial neurological examination revealed a Glasgow Coma Scale score of 4. CT scan showed a slight brain-stem blood infiltration spreading in a rostro-caudal direction. An unreactive high voltage, unalternating alpha pattern (8-9 Hz), uniformly widespread, was recorded during the first 3 days of monitoring, whereas later theta and then delta activity superseded. EEG-CSA proved to be useful in assessing: (1) this alpha coma pattern, its evolution in time and its poor prognostic value; (2) the relationship with CT scan to contribute to solving the problems correlated with the site of the lesion, electrocortical activity and consciousness. 124. Epilepsy in old age: clinical, EEG and CT study of 83 cases. - - R. Manni and A. Tartara (Pavia) A retrospective clinical, EEG and CT study was performed on 83 epileptic patients over 60 years of age. Fifty-three

epileptic subjects experienced their first onset of seizures between 64 and 83 years of age, and 30 epileptic subjects between 25 and 65 years of age. Some clinical differences were found between these two groups of patients. In fact, in the subjects with epilepsy onset after 65 years of age a higher percentage of apparently generalized seizures was noted as well as, among partial seizures, a prevalence of elementary motor seizures. Furthermore, a clinical picture similar to Gastaut's 'late onset secondary generalized epilepsy' was confirmed in patients with epilepsy onset after 64 years of age. As to the etiology of seizures, our findings confirm that in subjects with later onset epilepsy, vascular etiology prevails over tumoral etiology. 125. Epileptic seizures in hepatic encephalopathy. A possible role of inhibitor' neurotransmitte~. - - M. Mazza, M.G. Terzano, G. Pavesi, E. Bortone and D. Mancia (Parma) We examined 135cases of hepatic encephalopathy (HE) observed during the last 3 years at the Department of Infectious Diseases of Parma. The occurrence of epileptic seizures has been evaluated. Two patients had seizures (tonic-clonic type) in the hour before death. The extremely low incidence observed (1.5%) is discussed in relation to the peculiar biochemical alterations of HE. A possible role of GABA, a well known inhibitory neurotransmitter, is discussed. 126. Spectral EEG analysis in patients with chronic cerebrovascular diseases treated with cyticholin. - - A. Moglia, A. Arrigo, G. Bono, E. Sinforiani, C. Zandrini, G. Calabr6, G. Cinanni and G. Nappi (Pavia) Forty selected subjects with chronic cerebrovascular diseases received at random for periods of 4 weeks, i.v. infusion of cyticholin 1000 m g / d a y or placebo, respectively (double-blind study). After cyticholin treatment spectral EEG analysis revealed a significant decrease of the slow delta frequencies paralleled by a significant increase of the alpha activity. The results of neurophysiological investigation also demonstrated positive changes under cyticholin. 127. EEG asymmetry during acoustic cognitive tasks. - - L. Murri, A. Stefanini, E. Bonanni, L. Domenici, C. Navona and F. Denoth (Pisa) In this study the symmetry of EEG total power (1.2-30.0 Hz) and the powers associated with single frequency bands was evaluated in relation to cognitive acoustic tasks. Fourteen normal right-handed subjects (medical students and graduates), ranging from 25 to 32 years of age, were studied. Recordings were made from F4-C4, F3-C 3, P4-O2, P~-O1, Ta-Cz, T3-Cz while subjects were listening to white noise, to speech and to classical music. The log R / L ratio was calculated for all frequency bands. R / L ratio values were higher in parieto-occipital and temporal leads, but not in fronto-central derivations, during the

ITALIAN EEG SOCIETY, A N N U A L S P R I N G M E E T I N G verbal task. This pattern was particularly evident in the total power and in the alpha band. The data confirm a task-correlated EEG asymmetry but this asymmetry was not observed for all frequency bands and seems to be related to the leads used. 128. Free carbamazepine concentration in epileptic patients. Interpretation and clinical correlates. - - P.G. Nardi, M. Celadin, P. Pinelli and C. Ravenna (Mestre) Total and free fraction carbamazepine (CBZ) plasma levels were measured in 73 blood samples taken from a group of 40 epileptic patients chronically treated with CBZ. There was no evidence that CBZ free levels changed either in monotherapy or in polytherapy with PB, P B + D P H or P B + B D Z , and they were not related to associated PB plasma levels. Both total and free CBZ levels decreased in polytreatment. The results indicate that the determination of free fraction CBZ is not reliable. 129. Influence of endocrine levels on hemispheric distribution of lateralized EEG abnormalities. - - C. Paolozzi, M.R. Tara, A. Guizzaro and E. Volpe (Naples) The influence of sexual hormonal factors on biological asymmetries and the corresponding asymmetry of vulnerability between the two hemispheres were investigated. 4032 EEG records were examined. The prevalence of EEG vulnerability of the left hemisphere: (a) is present from the first year of life; (b) is always more marked in females; (c) increases significantly in puberty (earlier in females); (d) increases again, in females, during menopause. In view of evidence of a relationship between hormones and cerebral lateralization, the role of hormonal factors as a cause of interhemispheric asymmetries is stressed.

71P tion. A CT scan showed a severe bilateral cortical and subcor0cal atrophy. Criteria for differential diagnosis are proposed. Taken with observations in the literature, this case underlines the existence of primarily generalized epilepsy occurring late in life, probably predominant in females, with the features of confusional states with myoclonus. 131. Influence of sex steroid hormones on limbic kainate-induced epilepsy. - - F. Patti, P. Marano, R. Raffaele, G. Giammona, C. Maccagnano, A.M. Finocchiaro and Fr. Nicoletti (Catania) Oral contraceptives have been found to increase seizures in some epileptic patients. Estrogens are epileptogenic after application to brain cortex and after systemic injections, and they are clearly associated with certain cases of petit mat epilepsy. Progesterone or its derivatives affords protection against seizures. We have used kainate-induced epilepsy to investigate the role of gonadal steroids in seizure disorders. This epileptiform activity starts in the hippocampal formation and subsequently propagates to other brain regions. Interestingly, specific binding sites for steroid hormones are concentrated in the hippocampus, and the cyclicity in the hippocampal electrical activity parallels the cyclicity of gonadal hormones. Estrogen determined a potentiation of epileptiform activity with a significant increase in the number of tonic-chmic convulsions both in male and female rats. Repeated medroxyacetate progesterone (MAP) treatment produced a slight increase in the phenomena that occur in the first and second phases of kainate-induced epilepsy and a marked decrease in the generalized episodes. These data are interesting in view of a possible therapeutic use of MAP in seizure disorders.

130. Acute confusional state in an elderly female associated with myoclonus and paroxysmal generalized EEG abnormalities. - - L. Parrino, M. Marchini, G. Costani, A. Decembrino, M.C. Spaggiari and M.G. Terzano (Parma)

132. Antiepileptic plasma drug levels, liver function and haematological profile, i L. Pinessi, S. Gentile, P. Benna, D. Leotta, L. Tarenzi and B. Bergamasco (Turin)

An 80-year-old woman, with no family history of seizures, presented with a sudden episode of cloudy state of consciousness and impairment of speech and motor activity. The confusional state was associated with diffuse recurrent jerks. In recent years the patient had manifested similar episodes, which lasted as h m g as an entire day, beginning and ending spontaneously. A polygraphic recording showed paroxysmal discharges characterized by generalized polyspikes and waves accompanied by synchronous jerking movements of the eyelids, trunk and upper limbs. Routine biochemical tests were normal. The episode stopped spontaneously 48 h after its onset. The patient became lucid and presented a negative neurological picture, although signs of intellectual deterioration were noted. The interictal EEG record was within normal limits. However, polyspike and wave sequences closely related to myoclonus were induced by mean frequencies of intermittent light stimula-

The risk of adverse side effects is an unavoidable consequence of very intense drug use, particularly in such chronic treatment as antiepileptic therapy. We have evaluated whether there is a correlation between plasma levels of antiepileptic drugs and changes in some biological parameters (GT, transaminases, alkaline phosphatase, leucopenia etc.). Plasma drug levels were measured in 90 epileptics who showed changes in one or more of these parameters. Age, sex, antiepileptic drug type, serum levels of liver enzymes and results of blood tests were recorded for each patient. In 53 patients liver enzyme levels were at least 2-fold increased. 27 patients showed leucopenia, 10 patients were characterized by resolution of either liver function or haematological profile. Only in 11 patients (12.2%) were plasma levels of antiepileptic drugs higher than normal. In conclusion, we found no correlation between changes in biological parameters, and age, plasma drug levels or treatment protocol.

72P 133. Memory functions in relation to electroencephalographic changes in temporal lobe epileptic patients. - - L. Pinessi, D. Leotta, S. Gentile, I. Ralnero, L. Tarenzi and B. Bergamasco (Turin) Neurosurgical and clinical studies have demonstrated a hemispheric specialization concerning memory function. The left temporal lobe is related to verbal memory, the right one to non-verbal memory. In view of these findings, we tested verbal and non-verbal memory of two groups of fight and left temporal lobe outpatients and a group of controls. Left temporal patients showed a lower score of verbal memory compared with the other two groups. Moreover, all epileptic patients showed a lower global memory score than did controls. 134. Psychosexual evaluation of a group of epileptic patients. - - L. Pinessi, L. Tarenzi, S. Gentile, D. Leotta, L. Scarzella and G. Angelini (Turin) Behaviour impairments are not infrequent in epileptic patients. Sexual impairment may be a s y m p t o m of the disease, or it m a y be due to pharmacological treatment. Sexual behaviour disorders are more frequent in temporal lobe epilepsy than in primary generalized epilepsy. We have evaluated the psychosexual behaviour, during antiepileptic treatment, of 110 epilet~tic patients (60 temporal lobe epilepsy, 50 primary generalized epilepsy). The patients were similar for sex, age, sociocultural conditions, onset of the disease, crisis frequency and pharmacological treatment. All patients were submitted to a behavioural psychosexological test (Psycho-somatic Sexological Assessment in Medicine). Depressed sexual activity was demonstrated in 70% of epileptic patients (50 temporal lobe epileptic patients, 27 primary generalized epileptic patients).

135. Epilepsy in school and pre-school age: an epidemiological study in the province of Reggio Calabria. - - F. Pisani, C. Trunfio, G. Oteri, G. Primerano, A. Amendola D'Agostino, F. Strati and R. Di Perri (Messina) An epidemiological study on epilepsy in school and preschool age (3-14 years) was carried out in the province of Reggio Calabria (Southern Italy). Cases of febrile convulsions were not included. The prevalence of the disease was 4.3%0 a m o n g the 4000 children examined (prevalence day: October 24, 1981). The following aspects arose from the investigation: (i) teachers were quite willing to talk about epilepsy, but most of them showed only a superficial and approximate knowledge of the disease; (ii) the epileptic children were also willing to talk about epilepsy, but only in the absence of their teachers and classmates; (iii) their parents were usually suspicious and distrustful, tending to minimize the problem; (iv) 14 out of 17 epileptics were already diagnosed in specialized epilepsy clinics in Northern Italy.

SOCIETY P R O C E E D I N G S

136. Hyperinsulinism and epileptic seizures. Electro-clinical study of a case. - - M.R. Salati, M. Morchini, Boroni, Del Signore and D. Monicia (Parma) We examined a 14-year-old boy suffering from complex partial seizures, which occurred many times a day. The seizures began when the patient was 8 years old. He underwent various anticonvulsant therapies without success. When the patient was admitted to our ward his EEG showed spikes and spikes and waves in the right temporal region. Measurements of plasma insulin concentrations carried out during the seizures showed a very high level of this hormone. Further investigations did not reveal any insulinoma. The patient was administered diphenylhydantoin because of its anticonvulsant effects and its capability to inhibit insulin secretion. By means of this therapy we obtained a sharp decrease in the number of seizures and a reduction of the plasma insulin concentration. 137. Free phenytoin determined by EMIT in plasma ultrafiltrate: a correlation with tear levels. - - G.P. Sechi, G. Rosati, V. Porcella, A. Demurtas and F. Monaco (Turin) Phenytoin (PHT) free drug levels were determined in plasma ultrafiltrate with the EMIT Free-Level System I ®, and values were correlated with tear levels in the same epileptic subjects. A close correlation ( P < 0.001) was shown between plasma free levels and tear levels. The ratios between ultrafiltrate levels and plasma levels are similar to those with gas-liquid chromatography. For PHT the two methods seem equivalent as to reliability. 138. Electro-clinical findings during classical migraine attacks. - - P. Tinuper, P. Cortelli, T. Sacquegna and E. Lugaresi (Bologna) We report electro-clinical observations in two attacks of classic migraine, one on the left and one on the right side, in a 17-year-old girl. The patient was confused and amnesic when the headache was localized to the left side. The ictal EEG at the time showed important slow abnormalities on the left hemisphere, which gradually diminished during the 4 days after the attack. The migraine attack on the right side was not associated with significant EEG abnormalities. EEG recordings during classic migraine attacks have been rarely reported and were almost always normal. Impairment of consciousness during migraine attacks is usually attributed to brain-stem involvement. However there is some evidence that it could also be clue to dysfunction of the left hemisphere. The EEG abnormalities found in our case support the latter hypothesis. Moreover, it has recently been observed that in migraine attacks with 'confusion,' impairment of memory is the main disturbance, due to left temporal lobe involvement. The presence or absence of EEG abnormalities seems to be correlated also with the intensity of the attack.