Abstracts

RATIONALE: Selective amygdalohippocampectomy has been shown to be a safe and effective procedure for patients with intractable partial epilepsy of mesial temporal origin. Utilizing a stereotactic approach may improve patient tolerance of the operation and be associated with a lower post-operative morbidity. At the end of this activity the participants should be able to discuss operative outcome following stereotactic, selective amygdalohippocampectomy.
METHODS: We reviewed the clinical histories, pre-surgical evaluations and follow-up of consecutive patients with intractable partial epilepsy of temporal lobe origin who underwent stereotactic, selective amygdalohippocampectomy at the Washington University School of Medicine between 1997 and 2001. The mesial structures were accessed in all patients via a stereotactic middle temporal gyrus approach with hippocampal resection to the level of the colliculi. Patients with lesional epileptic syndromes and those followed for less than 6 months post-operatively were excluded.
RESULTS: A total of 38 patients were identified (mean age at surgery: 38.6 years; 22 male, 16 female). Thirty-three patients (86.6%) had mesial temporal sclerosis on seizure protocol MRI. Twenty-eight (73.7%) had unilateral concordant, interictal epileptiform activity while 10 patients (26.3%) had bilateral abnormalities. Seventeen patients (44.7%) had a history of febrile convulsions. Twenty-eight patients (73.7%) were seizure free following surgery while 31 (81.6%) experienced an Engel Class I-II outcome. Mean duration of follow-up was 16.3 months. MRI identified mesial temporal sclerosis was significantly associated with seizure freedom (27/33) compared to patients with normal MRI (1/5) (Fisher[ssquote]s exact test, p=0.01). No perioperative complications occurred in these patients.
CONCLUSIONS: Frameless, stereotactic, image-guided, selective amygdalohippocampectomy is an effective surgical approach for patients with intractable partial epilepsy of mesial temporal origin. The rates of seizure freedom approximate those of commonly used and more invasive temporal lobe surgical procedures. Further research is necessary to determine whether there is significantly improved patient tolerance and decreased utilization of health care resources using this approach.