CLINICAL AND ELECTROGRAPHIC MANIFESTATIONS OF LESIONAL NEOCORTICAL TEMPORAL-LOBE EPILEPSY

To determine whether lesional neocortical temporal lobe epilepsy (NTLE ) can be differentiated from mesial temporal lobe epilepsy (MTLE) duri ng the noninvasive presurgical evaluation, we compared the historical features, seizure symptomatology, and surface EEG of 8 patients seizur e free after neocortical temporal resection with preservation of mesia l structures and 20 patients after anterior temporal lobectomy for MTL E. Seizure symptomatology of 107 seizures (28 NTLE, 79 MTLE) was analy zed. One hundred one ictal EEGs (19 NTLE, 82 MTLE) were reviewed for a ctivity at seizure onset; presence, distribution, and frequency of lat eralized rhythmic activity (LRA); and distribution of postictal slowin g. Seizure symptomatology and EEG data were compared between groups, a nd sensitivity, specificity, and positive and negative predictive valu es were determined for variables that differed significantly. Multiple logistic regression was used to determine whether patients could be c orrectly classified as having MTLE or NTLE. MTLE patients were younger at onset of habitual seizures and more likely to have a prior history of febrile seizures, CNS infection, perinatal complications, or head injury. NTLE seizures lacked features commonly exhibited in MTLE, incl uding automatisms, contralateral dystonia, searching head movements, b ody shifting, hyperventilation, and postictal cough or sigh. NTLE icta l EEG recordings demonstrated lower mean frequency of LRA that frequen tly had a hemispheric distribution, whereas LRA in MTLE seizures was m aximal over the ipsilateral temporal region. We conclude that it may b e possible to differentiate lesional NTLE from MTLE on the basis of hi storical features, seizure symptomatology, and ictal surface EEG recor dings. This may assist in the identification of patients with medicall y refractory nonlesional NTLE who frequently require intracranial moni toring and more extensive or tailored resections.