Selection of ideal candidates for extratemporal resective epilepsy surgery in a country with limited resources

Aim. To investigate how to select ideal candidates for extratemporal resective epilepsy surgery, without compromising efficacy and safety, in countries with limited pre-surgical diagnostic facilities. Method. From the prospective database maintained at an epilepsy surgery centre in southern India, we reviewed the attributes of consecutive patients who had completed at least two years of follow-up after resections involving frontal, parietal and occipital lobes for medically refractory focal seizures. Results. Of 386 patients diagnosed with extratemporal refractory epilepsies during the study period, 61 (15.8%) were selected based on the presence of magnetic resonance imaging (MRI)-identified lesions (in all) and concordant scalp recorded electroencephalographic (EEG) data (in nearly two thirds). Seventeen (27.8%) required invasive investigations either to define the ictal onset zone, eloquent area, or both. During a median follow-up period of five years, 63% of our patients were seizure-free, excluding the presence of auras. Permanent disabling neurological sequelae occurred in three (4.9%) patients. According to univariate analysis, pre-operative secondary generalised seizures and interictal epileptiform discharges (IEDs), during a one-year post-operative EEG monitoring period, portended unfavourable seizure outcome. In multivariate analysis, frontal lobe resections and IEDs in post-operative EEGs were independent predictors of unfavourable outcome. Conclusions. Extratemporal resective epilepsy surgery can be undertaken in countries with limited resources with efficacy and safety, comparable to that in developed countries, when patients are selected based on the presence of MRI-identified lesions and scalp EEG concordance. In such patients, invasive EEG examinations, when necessary, can be undertaken by limited coverage of cortical areas at an affordable cost.