OUTCOME FOLLOWING SURGERY IN PATIENTS WITH BITEMPORAL INTERICTAL EPILEPTIFORM PATTERNS

We reviewed outcome at least 1 year after temporal lobectomy in 44 pat ients with bitemporal, independent, interictal epileptiform patterns o n EEG. All 44 underwent preoperative intracranial monitoring. Twenty-t wo (50%) were seizure-free, 14 (32%) had at a least 75% reduction in s eizures, and eight (18%) had less than a 75% reduction in seizures. We analyzed age of seizure onset, duration of epilepsy, gender, side of operation, history and clinical findings, findings on MRI, results of intracranial EEG-video monitoring, presence or absence of lateralizing neuropsychological deficits, and pathology of resected tissue to iden tify factors associated with outcome. Three factors emerged as indepen dently associated with a good outcome: concordance of MRI abnormality and side of operation (p = 0.01), history of febrile seizures (p = 0.0 4), and 100% lateralization of intracranially recorded ictal onsets to the side of operation (p = 0.05). A seizure-free outcome was much mor e likely to occur if more than one of these factors was present: with at least two factors co-existing, 83% (15/18) of patients were seizure -free, while only 35% (7/20) were seizure-free with a single factor pr esent (p = 0.0009), Of the six patients without any of the three facto rs, none were seizure-free. We conclude that it is possible to predict reasonably which patients with bitemporal epileptiform abnormalities will have a good outcome after surgery.