Transsylvian Selective Amygdalohippocampectomy for Mesiotemporal Epilepsy: Experience with 162 Procedures

Mesial temporal lobe epilepsy (MTLE) is one of the most common forms of epilepsy refractory to medical therapy. Among different surgical approaches, selective amygdalohippocampectomy has gained increasing interest for its rationale of isolated removal of the epileptogenic mesiotemporal area.

To summarize our experience with surgical treatment of MTLE in 162 patients using the transsylvian approach and to analyze possible effects of length of hippocampal resection and postoperative gliosis on seizure and cognitive outcome.

Clinical, radiological, histopathological and neuropsychological findings of 162 patients with MTLE who were operated by the senior author between 1993 and 2012 were retrospectively evaluated. Postoperative follow-up mounted up to 240 months (59 ± 56 months). Seizure outcome was available in 156 patients with minimum follow-up of 3 months. Extent of hippocampal resection was evaluated in 70 and postoperative gliosis in 62 of the 92 patients. Results were then correlated with seizure and cognitive outcome.

Of 134 patients with a follow-up of at least 1 year, 85 (63.4%) remained completely seizure free (Engel Ia) and 118 (88.0%) had a worthwhile improvement after surgery (Engel I+II). There was no perioperative death. Permanent morbidity was encountered in 4 patients (2.5%). Neither the extent of hippocampal resection nor postoperative gliosis correlated with seizure outcome or postoperative memory performance.

Transsylvian selective amygdalohippocampectomy can be recommended as an adequate procedure for the surgical treatment of mesiotemporal epilepsy with favorable epileptological results and acceptable morbidity.