Abstracts

RATIONALE: After temporal lobe resection for epilepsy some patients have a recurrence of seizures after a seizure free period. Although often an emotionally upsetting event, there may be only 1 or 2 seizures in the year of recurrence. The objective of this study is to determine how often this recurrence of rare seizures represents a return of medically refractory epilepsy.
METHODS: Data from our earlier study of a 5 and 10-year follow-up outcome of 93 patients with medically refractory temporal lobe epilepsy treated with surgical resection vs. a matched group of medically treated patients were examined. (Haglund MM and Ojemann LM: Seizure Outcome in patients undergoing temporal lobe resections for epilepsy. Neurosurgery Clinics of North America, 4:2: 337-344, 1993). In that study, year-by-year seizure counts were obtained. These were examined in the 67 patients in the 5 year surgically treated group and the 26 patients in the 10-year surgical group. Cases with 1 or 2 seizures in the first post-operative year, or those with one or more seizure free years immediately after operation, followed by a recurrence were identified. The subsequent course of those patients was ascertained. Patients with post op seizures were kept on or placed back on antiepileptic drugs (AEDs). We reviewed the history for major events and for AED tapering.
RESULTS: Eleven patients had 1 or 2 seizures in the first year following surgery. Five of these 11, (45%) were seizure free for the ensuing 4 years of maximum follow up. Twenty one patients were seizure free one or more years post-op and had a recurrence of 1 or more seizures. Fifteen of the 21, (72%) had a single seizure in the year of recurrence. Eighteen of 21 these patients had a follow-up of at least 2 years after the year of recurrence: 9 of 18 (50%) with a 2-year follow up were seizure free in those 2 years after recurrence. 13 were followed for 3 years after recurrence, 5 (38%)were seizure free for the 3 years. 3 were followed for 6 years after recurrance, 1 (33%) was seizure free for those 6 years. Thirteen of the 18 had a single seizure during year of recurrence. Of the 13, 8 (62%)were seizure free for the 2 year follow up. 10 of these were followed for 3 years after recurrence, 5 (50%) were seizure free in those 3 years. Three of these had a 6 year follow up after recurrence and 1 (33%) was seizure free for those 6 years.
CONCLUSIONS: The occurrence of 1 or 2 seizures in the first postoperative year does not necessarily mean the return of medically refractory epilepsy; almost 1/2 of these patients will have no seizures in the next 4 years. Recurrence of seizures after 1 or more seizure free years immediately following the operation also does not mean return of medically refractory seizures. Most recurrences will be only a single seizure in that year. Half of these patients with a recurrence will be seizure free for the next two years. Having only a single seizure in the year of recurrence improves this outcome. There was no statistical correlation of major stressful events, or of AED tapering with the reccurrence of these rare seizures.