Abstracts

Cyclic changes in neuroactive steroid concentrations may induce variation of seizure frequency. Herzog et al. (Epilepsia 1997;38:1082-8) have provided statistical evidence for the occurrence of 3 patterns of catamenial seizure exacerbation (CSE): 1) perimenstrual (C1: Day -3 to 3), and 2) periovulatory (C2: Day 10 to -13) in ovulatory cycles, and 3) luteal (C3: Day 10 to 3) in anovulatory cycles. They also determined mathematically based levels of seizure exacerbation for designation of CSE for each of these patterns. Sensitivity and specificity of these 3 patterns as predictors of ovulation, however, remain to be established. 87 women, 13-45 years of age, with refractory localization-related epilepsy recorded seizures and menses during 3 cycles. A midluteal progesterone level [lt] 5 ng/ml was used to designate anovulatory cycles. The menstrual cycle was divided into 4 phases: menstrual (M) = -3 to +3, follicular (F) = 4 to 9, ovulatory (O) = 10 to -13 and luteal (L) = -12 to -4. Average daily seizure frequency (ADSF) for each phase was compared among phases. Comparisons were carried out separately for ovulatory and anovulatory cycles. CSE designation was made if seizure exacerbation exceeded predetermined levels: C1 - ADSF during the M phase relative to the F and L phases in ovulatory cycles [ge] 1.69; C2: ADSF during the O phase relative to the F and L phases in ovulatory cycles [ge] 1.83; and C3: ADSF during the O, L and M phases relative to the F phase in anovulatory cycles [ge] 1.62. The frequency of each pattern in relation to ovulatory and anovulatory cycles was tabulated and proportions were compared using [Chi]² analysis. The distribution of catamenial patterns in relation to ovulatory and anovulatory cycles is presented in Table 1.[table1] Sensitivity and specificity values for catamenial patterns 1 and/or 2 in predicting ovulation and pattern 3 in predicting anovulation are presented in Table 2.[table2] Ovulatory cycles that showed the C3 pattern had higher midluteal estradiol/progesterone ratios than those that showed C1 and/or 2 patterns: 12.5[plusmn]5.6 vs 8.0[plusmn]3.7 (p=.01). Catamenial patterns of seizure exacerbation differ significantly between ovulatory and anovulatory cycles. C1 and 2 patterns are both highly sensitive and specific for ovulatory cycles. C3 is quite sensitive, but lacks specificity, for anovulatory cycles because it relates to high E/P ratios regardless of ovulation. (Supported by NIH RO1 NS39466)