Neuropsychological assessment in epilepsy surgery - preliminary experience in a rural tertiary care hospital in north East malaysia

We present our preliminary experience in neuropsychological testing in epilepsy surgery patients to demonstrate how these tests contributed to decide the laterality of epileptic focus, and to assess the effect of surgery on patient's cognitive function and quality of life. Preoperative neuropsychological tests consisting of Wechsler Adult Intelligence Scale-III (WAIS) for IQ, Wechsler Memory Scale-III (WMS) for memory and patients' quality of life (QOLIE 31) were administered to refractory epilepsy patients under evaluation for surgical treatment. These tests were repeated one year after surgery and we studied any changes in trends. A total of seven patients were recruited in this study between July 2004 and July 2006. The aetiologies of refractory epilepsy were pure mesial temporal sclerosis (MTS) in five patients, dysembryogenic neuroepithelial tumour (DNET) in one and dual lesion of cavernous angioma with ipsilateral MTS in one. The preoperative neuropsychological tests were all in concordance to MRI finding, and showed good contralateral function; five lateralises to the right and two to the left. The post-operative Engel seizure count (median 8.00, IQR 7.00-8.75), general IQ (88 vs. 79), performance IQ (94 vs. 79), verbal memory (89 vs. 71), non-verbal memory (88 vs. 75) and QOLIE (53.14 vs. 44.71) were better compared to preoperative values. The verbal IQ (84 vs. 84) was unchanged. Neuropsychological tests are useful as ancillary investigations to determine the laterality of seizure focus and integrity of function in the contralateral temporal lobe. Following successful surgical treatment, there is a trend towards improvement in memory, IQ and quality of life scores in this small group of patients.