NOCTURNAL TEMPORAL-LOBE EPILEPSY

Objective: To analyze clinical, electrophysiologic, and neuroradiologi c characteristics and prognostic factors in a group of patients with t emporal lobe epilepsy (TLE) and complex partial seizures (CPS) occurri ng exclusively or predominantly after they fall asleep or before they awaken. Background: CPS arising during sleep are classically identifie d with frontal lobe epilepsy. TLE associated with seizures occurring o nly or predominantly during sleep (nocturnal TLE) is less common. Meth ods: From a series of patients with refractory TLE studied between 198 0 and 1996, the authors identified 26 patients (15 men) with nonlesion al nocturnal TLE (mean age, 40 years). Clinical and laboratory charact eristics of these individuals were studied and compared with a group o f 72 age-matched, randomly selected patients with nonlesional TLE and predominantly diurnal seizures (diurnal TLE). Results: Mean age at sei zure onset was similar for both groups (16.3 versus 18.7 years). In th e nocturnal TLE group, 2 of 26 patients had a positive family history of epilepsy, 18 reported an aura, 4 presented with CPS in clusters, 11 had unilateral and 15 bilateral temporal EEG abnormalities, and 14 of 21 studied had unilateral mesial temporal atrophy. None of these fact ors differed significantly in the two groups except for higher frequen cy of the following in the diurnal TLE group compared with the nocturn al TLE group: positive family history for epilepsy (33% versus 8%, p = 0.01), estimated frequency of seizures (median, 14 versus 2 per month ; p < 0.01), and presence of antecedent febrile convulsions (33% versu s 11%, p = 0.04). In the nocturnal TLE group, eight patients underwent surgical therapy and became seizure free (follow-up, >12 months). Onl y two were seizure free on medication. Conclusions: Infrequent and non clustered seizures, rare family history of epilepsy, and low prevalenc e of childhood febrile convulsions characterize nocturnal TLE. Within the TLEs, the nocturnal TLE form seems to have a better surgical progn osis.