Abstracts

Tuberous Sclerosis (TS) commonly presents with medically refractory epilepsy. Epilepsy surgery may offer the best chance of cure from seizures, however there is paucity of published literature from large epilepsy centers evaluating its efficacy.
[underline]Objective:[/underline] 1)To review the epilepsy characteristics of patients with TS who underwent epilepsy surgery at our institution 2)To review the long-term outcome in this patient population.
The epilepsy database was searched for patients who underwent surgery between1981-2002. Patients with at least 6 months of follow up after surgery were included. They were classified as having concordant findings when: a) they had single seizure type by clinical description b) all EEG seizures and more than 50% of the interictal sharp waves localized to the same epileptogenic focus and, c)the intracranial lesion (if single) or the largest intracranial lesion (when multiple) on MRI corresponded to the epileptogenic focus . Patients who did not fulfill the above criteria were classified as non-concordant. Data regarding demographics, seizure types, interictal and ictal EEG, MRI, type of surgical resection and seizure outcome was obtained from retrospective review of clinical charts. Post-surgical outcome (seizure freedom vs recurrent seizures) was compared between the two groups (concordant and non-concordant).
19 patients with TS underwent surgery for epilepsy at the CCF from 1981-2002. 5 patients were excluded (4 had less than 6 months of follow up and one was lost to follow up). 14 patients were followed for 6mo to15 years (mean 3 years) after surgery. Age of seizure onset was 2 days to11 years (mean 3 years). Age at surgery was 2 months to 31 years (mean 13 years). More than 50% of the interictal sharp waves were localized to one region in all patients; the remaining sharp waves were multiregional or generalized. EEG seizures were of temporal lobe origin in 7 patients, extratemporal in 6 patients, and non-localizable in one. MRI was performed in 13 patients; 3 had a single lesion, while 10 had multiple bilateral lesions. 8 patients had concordant findings while 6 had non-concordant findings. 9 patients underwent temporal lobectomy and 5 underwent an extratemporal resection. Pathology was available in 12 patients and it was consistent with TS in all.Overall, 9/14 (64%) patients were rendered seizure free. In the concordant group, 6/8 (75%) of the patients became seizure free, while 3/6 (50%) with non-concordant findings became seizure free. In all the patients with recurrent seizures, the seizure burden was significantly reduced in the postoperative period.
Epilepsy surgery may offer the best chance of cure or significant improvement from refractory epilepsy in patients with TS. The concordance of clinical, electrographic and MRI findings increases the likelihood of seizure freedom after surgery.