TEMPORAL AND SPATIAL CHARACTERISTICS OF INTRACEREBRAL SEIZURE PROPAGATION - PREDICTIVE VALUE IN SURGERY FOR TEMPORAL-LOBE EPILEPSY

We examined the prognostic value of spatial and temporal characteristi cs of intracerebral propagation of seizures during temporal lobe epile psy (TLE) surgery. Seven TLE patients resistant to standard anterotemp oral lobectomy who had no known causes of resistance [e.g., extratempo ral (ET), lesions, multifocal epilepsy] were matched with 7 seizure-fr ee patients and 7 others who were almost seizure-free after operation. Intracerebral ictal propagation pathways were not different in the th ree groups. Propagation was multidirectional, most frequently to the f rontal lobes and sometimes to the contralateral temporal lobe (CTL). E T propagation delays were significantly shorter in resistant patients than in markedly improved patients. The resistant group also had more frequent propagation delays <1.0 s, but propagation times >1.0 s were equally likely in all groups. The extent of ET propagation and frequen cy of focal onsets were not different among the groups. Results sugges t that very short propagation times predict reduced efficacy of operat ion, and that long propagation times are not related to surgical succe ss.