Abstracts

Traumatic brain injury may result in diffuse, focal and/or multifocal changes with sites of epileptogenesis coinciding with the site of apparent injury and/or remotely. Surgical outcomes in temporal and extratemporal epilepsy cases may therefore reflect certain mechanisms underlying the injury and possibly differ from those achieved in nontraumatic cases. An archival review of operated cases of epilepsy over a 10-year period (1993-2003) was undertaken. Both resections and vagus nerve stimulator implants were included in the review. Patient profile, duration of epilepsy, age at injury, mechanism, site of epileptogenicity and surgical outcome of posttraumatic epilepsy (PTE) cases were assessed and compared with certain features found in the overall review of surgical epilepsy cases. Posttraumatic epilepsy accounted for 16% of the total surgical epilepsy case load. The mean age at injury was 12.5 y and the duration of epilepsy was 19.8 y. There was no lobe-specific predilection towards epileptogenesis for injuries sustained before the age of 10 y. Of the 52 patients (31M, 21F), 31 required prolonged extraoperative electrocorticography. A total of 46 resections were performed with 2 patients undergoing 2 resections each. Pure temporal lobe resections (TLRs) occurred in 26 patients (12R, 14L) with a further 11 requiring an additional extratemporal resection. Vehicular accident cases accounted for 35 % (18 patients) of cases. In the latter category, 12 (67%) had undergone pure TLRs. Overall, 14 patients underwent vagus nerve stimulator implants, 6 of whom had prior resections. Of the pure TLR cases, 58% remain free of disabling seizures after a minimum of 1 year of followup and of the total number of surgically treated posttraumatic cases, 44% are free of seizures. A selective lobar vulnerability towards epileptogenicity exists with medial temporal structures predominating. Age at injury appears not to dictate a preferential site of epileptogenicity. Surgical outcomes with posttraumatic TLE mirror those obtained in nontraumatic cases. Vehicular trauma accounts for a high proportion of posttraumatic temporal lobe epilepsy.