Menstrual disorders and infertility are common among women with epilepsy of temporal lobe origin (TLE). Reproductive endocrine disorders may be the cause. Polycystic ovarian syndrome (PCO) and hypothalamic amenorrhea (hypogonadotropic hypogonadism, HH), in particular, are significantly overrepresented and attributable to hypothalamic dysfunction. We therefore compared the hypothalamic function of 14 women with clinically and electrographically documented TLE with that of eight age-matched normal controls by determining the interictal pulse frequency and amplitude of luteinizing hormone (LH) secretion. Serum for LH measurement was drawn every 15 minutes from 8 AM to 4 PM in both groups. LH pulse frequency values were significantly more variable (p < 0.05) and lower (p < 0.05) among women with TLE than among controls. Women with left temporal EEG foci showed a trend toward higher pulse frequencies compared to women with right foci (p = 0.05 to 0.10). Among five women with reproductive endocrine disorders, the three with PCO had left-sided foci and average LH pulse frequency two times higher than that of the two women with HH, who had right-sided foci. Eight reproductively normal, medically treated women with TLE had significantly lower LH pulse frequencies than did the one reproductively normal, untreated woman with TLE (p < 0.05) and the eight normal controls (p < 0.001). These findings suggest that LH pulse frequencies in women with TLE may be influenced by the laterality of the epileptic focus, the reproductive endocrine status, and the use of antiseizure medications.

We compared the pulsatile secretion of luteinizing hormone (LH) between 13 men with clinically and electrographically documented temporal lobe seizures and 8 age-matched controls. Serum for LH measurement was drawn every 15 minutes during 8 hours of EEG telemetry in both groups. The 2 groups did not differ significantly in average mean baseline LH secretion, total LH secretion, or average pulse amplitude. The group with seizures, however, showed a significantly greater (p less than 0.05) variability of baseline LH secretion and pulse frequency. Among the men with unilateral paroxysmal EEG findings, pulse frequency was significantly greater (p = 0.05) with right epileptiform discharges or left slowing (6.4 +/- 0.4) than with left epileptiform discharges or right slowing (3.0 +/- 1.3). The relationship of pulse frequency to the nature and laterality of paroxysmal discharges makes it unlikely that endocrine abnormalities can be attributed to medication alone and strengthens the notion that temporal lobe epileptiform discharges may disrupt hypothalamic regulation of pituitary secretion.

In a study of 16 men and 55 women with temporal lobe epilepsy (TLE), we found that the serum dehydroepiandrosterone sulfate (DHEA-S) level was significantly lower (P less than 0.05) in patients who were treated with phenytoin (mean +/- SD DHEA-S in men, 685 +/- 429 ng/ml; in women, 580 +/- 289), carbamazepine (women, 779 +/- 529), or a combination of the two drugs (men, 491 +/- 246; women, 474 +/- 284) than in age- and sex-matched untreated patients (men, 2634 +/- 418; women, 2011 +/- 1435) or in normal subjects (men, 2870 +/- 1052; women, 1764 +/- 617). DHEA-S values in the treated groups did not differ from one another. The DHEA-S levels in untreated patients with TLE did not differ significantly from those in normal subjects. TLE alone, therefore, is unlikely to account for the decrease in DHEA-S, and thus, the results suggest that the antiseizure medications are capable of reducing DHEA-S levels. These findings are important because DHEA-S levels are often measured as part of a battery of tests to assess endocrine function in conditions such as polycystic ovarian syndrome, which may be over-represented among women with TLE.

Reproductive and sexual dysfunction in men with epilepsy has been attributed to androgen deficiency. Low serum free testosterone (FT) levels occur in both hypogonadotropic and hypergonadotropic hypogonadism. Antiepileptic drugs (AEDs) have been implicated. Proposed mechanisms include induction of increased sex hormone binding globulin (SHBG) resulting in decreased FT, as well as dysfunction or premature aging of the hypothalamopituitary-gonadal axis. In an investigation comparing serum reproductive steroid levels among 20 men receiving phenytoin (PHT) monotherapy for complex partial seizures, 21 untreated men with complex partial seizures, and 20 age-matched normal controls, total estradiol levels were significantly higher in the PHT group (56.3 +/- 29.4 pg/ml, mean +/- SD) than in the untreated (32.4 +/- 27.4 pg/ml, p less than 0.01) and normal control (34.3 +/- 12.7 pg/ml, p less than 0.05) groups. The physiologically active non-SHBG-bound serum estradiol levels were also significantly higher in the medicated group (45.1 +/- 21.7 pg/ml) than in the untreated (29.9 +/- 17.2 pg/ml, p less than 0.01) and normal control (31.1 +/- 11.4 pg/ml, p = 0.05) groups. These findings suggest that PHT may lower FT by induction of aromatase, enhancing FT conversion to estradiol, as well as SHBG synthetase. Estradiol exerts a potent inhibitory influence on luteinizing hormone secretion and has been suggested to play a major role in negative feedback in men as well as women. Suppression of LH secretion results in hypogonadotropic hypogonadism. Chronically low FT leads to testicular failure and hypergonadotropic hypogonadism. Finally, estradiol has been shown to produce premature aging of the hypothalamic arcuate nucleus, which secretes gonadotropin-releasing hormone.

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