HYPOGONADOTROPIC HYPOGONADISM AND TEMPORAL LOBE EPILEPSY MICHAEL M. ZIEGELBAUM, M.D. From the Division of Male Infertility, State University of New York at Stony Brook, New York
ABSTRACT--The concomitant finding o] hypogonadotropic hypogonadism and temporal lobe epilepsy raises the issue of whether or not these entities are related. The case presented herein is one such example. The possible pathophysiologic basis o] in]ertility and temporal lobe epilepsy is reviewed.
Isolated hypogonadotropic hypogonadism is a ~ell, documented cause of male infertility. 1 The idiSorder is often associated with neurologic abnormalities, including cranial nerve disorders, ~ental retardation, and cerebellar dysfunction. iThis report describes the finding of hypogona~dotropic hypogonadism and an associated temp0ral lobe disorder characterized by olfactory ~ u c i n a t i o n s and seizure activity. ii ¸
Case Report :-year-old Hispanic male comrtility for seven years. He has one child by his current wife, but y took six years to achieve. His a complete gynecologic workup ann was not found to have any ovulatory or ~enstrual dysfunction. The patient notes norreal libido, erection, and ejaculation. He uses a0 rnedieations, alcohol, or illicit drugs. Physii¢~ examination was remarkable for testicles of i :soft consistency bilaterally. The testes ~ a s u r e d 3.5 x 2 x 2 em on the right and 3.5 ~:2.5 x 2.5 em on the left. ii S e m e n analyses were obtained on three separate occasions (Table I). Pooled serum prolaetin Was 8 ng/dL (normal 0-16). Luteinizing hori :~~one (LH) was 6.5 mIU/cc (normal 5-20), and ! olliele-stimulating hormone (FSH) was 8.3 rnIU/cc (normal 5-20). Testosterone level was !95 ng/dL (normal 300-1200). LH and FSH are inappropriately low for the observed testosRoLocy /
terone level. Liver function tests, cortisol, prolactin, and thyroid function tests were normal. A computerized tomography (CT) scan of the sella turcica was normal. A post-ejaculatory urine did not demonstrate any spermatozoa. A gonadotropin releasing hormone (GnRH) stimulation test was administered. The response of LH, FSH, and testosterone to a test dose of 100 #g of intravenously administered GnRH was evaluated (Table II). The observed elevation of FSH and LH in response to GnRH is compatible with hypogonadotropic hypogonadism that is hypothalamic in origin. The patient began a course of 2,000 U of intramuscular HCG three times per week. A follow-up testosterone evaluation after six weeks on treatment was 660 mg/dL. Semen quality improved. Motility was 10 percent though the numbers of sperm were not altered. Shortly after beginning therapy, the patient complained of unusual odors, mood changes, fainting, and dizziness. He dated the symptoms to prior to treatment but had not been bothered by them and neglectd to include the symptoms in his history. After extensive requestioning, he did admit to head trauma during a brawl nine years prior to this episode which was never medically evaluated. Repeat neurologic examination and magnetic resonance imaging (MRI) of the head were unremarkable. An electroencephalogram was consistent with a bitemporal seizure disorder and olfactory hallucinations. The HCG was
VOLUME XXXVIII, NUMBER 3
TABLEI. Analysis 1 2 3
Ph 7.2 7.2 7.4
GnRh stimulation test (I00 mg L H - R H I V at T = O)
Vol. (co) 0.6 1.0 2
Cone. (cc) 2 x 10B 2 x 10~ 10~
Motility* 0 0 0
F S H (mlU/ce) L H (mIU/cc) Testosterone
*All spermatozoa dead.
discontinued at that time, and the patient started taking antiseizure medications. Seizure control was obtained with phenytoin and primadone. Three months after stopping the HCG and beginning the antiseizure medications, a repeat endocrine evaluation was done. LH rose to 12 mIU/cc percent, FSH to 6.9 mIU/ cc. These are appropriate levels for his current level of testosterone (508 ng/dL). A semen analysis demonstrated increase in numbers (12 × 10~/cc, 3.5 cc) and motility (15% motile). Comment An association between the extrahypothalamic brain and gonadotropin secretion is well established. ~ Hypogonadotropic hypogonadism secondary to temporal lobe lesions has been demonstrated in animal models. ~ Sexual dysfunction in humans associated with temporal lobe epilepsy may have a neuroendocrine basis. 2-5 Blumer 5 described diminished libido in patients with temporal lobe epilepsy. More recently, reports have demonstrated that hyposexuality accompanies temporal lobe epilepsy in over 50 percent of affected men and women. ~-4 Furthermore, the hyposexual individuals were less responsive to hormone replacement than would be expected in cases of isolated h y p o g o n a d o t r o p i c h y p o g o n a d i s m . Once the seizure disorder is controlled though, the endocrinopathy reverses often without the need for additional replacement hormone; this appears to have occurred in our patient. Differences in pathogenesis of the hyposexuality and/or infertility may exist among the patient population. The p a t i e n t described herein claimed no sexual dysfunction and had normal prolactin level. His gonadotropins were inappropriately low for the level of testosterone. Others report a mix of findings including hypogonadotropic hypogonadism (with or without elevation in prolactin), hypergonadatropic hypogonadism and loss of libido, or infertility with normal libido. 2-4 The pathophysiology of the hyposexuality is likely based on the altered input from the lira-
bic structures on the hypothalamus. Androgeni: receptors have been identified in the amyg, i dala. 2 Pathways exist between that structure!! and the ventromedial nucleus as well a, beroinfundibular neurons of the arcu cleus. ~ These nuclei are sites of control dotropin and prolactin secretion. The stimulatory and inhibitory influences limbic system on the hypothalamus r count for the variety of clinical symptoms. ~i While the former is a plausable explanation;~ one must also consider the converse. Endocrih6~ logically based sexual dysfunction may ehclt ....... ab~'-~'~i normal temporal lobe activity.,Testosterone h~i)~~' been shown to raise the seizure threshold in a~;~:!i mals. 3 Finally, the association b. disorders may be based on the of these lesions. The possibfl linkage exists. 3 This case report provides furtt the association of temporal lo1: hypogonadism. The impact ant neurologic function on sexuality enormous. The variety of findin I use of any particular laborat, clinical entity to identify those temporal lobe epilepsy. The a have implications for patients and psychiatric disorders, espe fecting the limbic system.
1300 Union New Hyde Park, New Y¢ References 1. Swerdloff RS: Physiology of male lamie-pituitary function, in Campbell's [ Walsh PC, Gittes RF, Perlmutter A, and delphia, W.B. Saunders e-~ l o ~ ~ l~a 2. Spark RF, Wills C prolactinemia, and tern Lancet 1:413 (1984). 3. Herzog AG, et al: with partial seizures of tl 341 (1986). 4. Herzog AG, e t a women with partial s~ Neurol 43:347 (1986). 5. Blumer D: Chan$ lobe disorders in man, J . . . . . . . . . . . ~. . . . z.