Abstracts

Rationale: Epidemiological studies indicate that the overall incidence of epilepsy is slightly higher in the male than in females. Partial epilepsies are more common among men, while generalized epilepsies prevail in women. Sexual dimorphism related to phenomenology of seizures has been described in temporal lobe epilepsy related to mesial temporal sclerosis (TLE-MTS). Probably differences between sexes are expressed early in life, when differential rates of cerebral maturation occur. According to Taylor’s hypothesis, there would be biological basis for the higher vulnerability of the male brain and of the left hemisphere. Cerebral maturation would be more rapid in girls, so that boys would be at a greater risk for a longer time. A potential seizure-producing insult would affect the less functionally active side, the left hemisphere. Some findings such as isolated auras, emotional and sexual auras and lateralized ictal pattern would be more frequent in women. On the other hand, men would experience secondary generalization more often. Objective: To study epilepsy characteristics, seizure phenomenology and differences of ictal behavior between sexes. Methods: Data from 150 patients submitted to pre-surgical evaluation due to refractory unilateral TLE-MTS was retrospectively analyzed. All patients had prolonged scalp-sphenoidal video-EEG recording and a 1.5 T MRI. Results: Results: There were 86 women and 64 men. Seventy-four (49.3%) suffered initial precipitant injury (IPI), being 35 female and 34 male. Age at IPI was undermined in 5. While 25 (71.5%) women had IPI in the first 2 years of life, they were equally distributed throughout the first 5 years in men. Auras (pushing the button > 50% of their seizures) were recorded in video-EEG in 33 females (38.3%) and 18 males (28.1%). As to types, 39 (45.3%) women presented ≥2 types of auras in contrast with the figures in 17 men (26.5%). Ictal fear was described by 17 patients (14 females). Sexual aura occurred in only one woman with right MTS. Thirty-four subjects (22.7%) presented >50% of secondary generalization being 21.8% of the men and 23.2% of the women. Our data confirmed Taylor’s hypothesis showing a slight decline in male distribution throughout the initial five years of life while the majority of females had IPI in the first two years. The earlier the IPI, the more the left hemisphere was affected. Regarding ictal behavior, women presented a greater number of auras and types of auras; among them, ictal fear was more prominent. Finally, secondary generalization was equally seen in both sexes. Conclusions: There are differences between genders in epilepsy characteristics and seizure expressiveness in TLE-MTS probably related to anatomical and functional development of the brain.