ABSTRACT
PURPOSE: To investigate the relationship of the resection extent of hippocampus and temporal neocortex with the postsurgical outcome in patients with mesial temporal lobe epilepsy (TLE). METHODS: Sixty-eight patients with TLE underwent brain MRI pre- and post-operatively. They were divided into two groups by seizure outcomes:seizure free group (SF, N=54) and non-seizure free group (NSF, N=14). Patients were classified further according to the post-surgical memory changes:MD group (with postsurgical memory decline, N=15) and NMD group (without postsurgical memory decline, N=16). The hippocampal resection was estimated by subtracting the length of post-surgical hippocampus from the pre-surgical length. The resection of temporal neocortex was measured by comparing the resection lengths on superior, middle, inferior and basal temporal gyri shown on three dimensional brain MRI. RESULTS: The mean extent of hippocampal resection was significantly larger in SF than in NSF (33.2+/-7.5 mm vs. 24.8+/-7.4 mm p=0.001) while that between MD and NMD was not significantly different. The resection extent of temporal neocortex was not significantly different between SF and NSF as well as between MD and NMD, but the resection extent of basal temporal gyrus of left TLE was significantly larger in MD than in NMD. CONCLUSIONS: The hippocampal resection was significantly greater in SF. The overall resection extent of the temporal neocortex did not correlate to the surgical outcomes of seizures or memory although that of the basal temporal gyrus of the left TLE was larger in MD.