Abstracts

Rationale: To assess outcome of epilepsy surgery for patients with medically refractory epilepsy in a tertiary care hospital in India Methods: Data of patients with medically refractory epilepsy who underwent epilepsy surgery after a standard presurgical diagnostic work-up was evaluated retrospectively. Standard workup included long-term video EEG telemetry, 3T MRI Brain and neuropsychological evaluation. Additional tests like PET Brain, ictal SPECT, functional MRI and intraoperative monitoring were done as appropriate. Postoperative MRI was done in most patients. Post-operative EEG was performed in all patients one week after surgery. Engel outcome was determined at 6 months, 5 years and at last follow up. Results: 75 patients fulfilled the criteria. Age of patients at surgery ranged from 21 months to 55 years. 40( 53%) were males and 35 ( 47%) females. Mean follow-up post surgery was 44 (1-85) months. 73 patients had lesions on MRI. Eleven had multiple MRI lesions but presurgical evaluation identified a single epileptogenic focus. The location of epileptogenic MRI lesion was temporal in 58, frontal in 13, Parietal in 3 and occipital in 1. 2 patients with normal MRI had focal hypometabolic area on PET. 21 patients (28%) underwent additional evaluation viz. ictal SPECT, PET and functional MRI. 18 underwent intraoperative electrocorticography and evoked potentials monitoring. 3 patients had awake surgery for functional brain mapping. Twenty patients were offered invasive monitoring but chose to undergo one stage surgery. The reasons included costs and reluctance for two surgeries. The commonest surgery performed was anterior temporal lobectomy (73.47%) followed by resections in frontal (17.33%), parietal (4%) and occipital lobes (1.3%) . Two patients had a functional hemispherotomy(2.6%) and one had a corpus callosotomy(1.3%), two had multilobar resections . The commonest pathology was hippocampal sclerosis (HS) in 41 (54.66%) and focal cortical dysplasia in 19( 25.33%), developmental lesions in 3( 4%), LEATs* in 7 (9.33%), extratemporal gliosis in 2 (2.6%) and cavernoma in 3 (4%). Dual pathology was identified in 13 and 2 had bilateral MTS. Acute postoperative seizures occurred in 3 patients. Out of 69 available postoperative EEG records, 16 (23.18%) showed epileptiform discharges. 5 patients were lost to follow up from this cohort. At 6 months follow up 60 /64(93.75 %) had Engel class 1 outcome. At last follow-up, 54/70 (77.14%) were seizure free and Engel's Class 1 outcome was noted in 65/70(92.85%). At 5 years post surgery 20/22(90.90%) had Engel's class 1 outcomes. Conclusions: In our cohort, 92.85% patients achieved Engel's class I outcomes. Costs possibly prohibit use of invasive monitoring. However, excellent outcomes after epilepsy surgery can be obtained from a careful patient selection even whilst only using non- invasive presurgical evaluation protocols. Abreviation- * Long term epilepsy associated tumors Funding: No funding was received for the above study.