Abstracts

Thirty-six patients who had unilateral anterior temporal lobectomy with amygdalohippocampectomy (ATL) or transsylvian selective amygdalohippocampectomy (TSA) were evaluated using a selection of cognitive tests before and one year after surgery, to examine whether the TSA produces less cognitive impairment than a standard [italic]en bloc[/italic] resection. We described 36 patients who had temporal lobe surgery between 1991-2003. The patients had either a left or right ATL or a left or right TSA. In 17 patients ATL and in 19 patients TSA was performed. All patients received comprehensive neuropsychological testing of IQ and verbal/non verbal memory before and one year after operation. There were no differences between groups on the ratio of seizure free(ATL 70.6%, TSA 73.7%).IQ was improved postoperatively in ATL and TSA groups. For ATL, verbal memory was impaired in left-side resections while non-verbal memory was impaired in right-side resections. Although a decline in verbal memory was found for the left-side TSA, significant improvement in verbal memory was found for the right-side TSA and no apparent decline of memory function except verbal memory in left-side TSA were indicated. The results clearly indicate that, particularly, left-side ATL and TSA can lead to a significant decline in verbal memory functions. However, in general, the preservation of memory function in the TSA group was better than in the ATL group. TSA may thus minimize the cognitive consequences of temporal lobe surgery.