Abstracts

Rationale: Selective amygdalohippocampectomy is an accepted surgical option for patients with refractory mesial temporal lobe epilepsy (MTLE). Limited data exists to suggest widespread use of SAH. We present the seizure outcome from a consecutive series of patients treated with SAH since it was first utilized in the Calgary Comprehensive Epilepsy Program. Methods: A retrospective review of all patients who have undergone SAH for suspected MTLE at Foothills Medical Centre, with minimum one year follow up, was completed. All patients underwent a comprehensive epilepsy surgical work up including VEEG, MR imaging and neuropsychological evaluation. Patient data collected included age of onset of epilepsy, age at surgery, seizure types and frequency, results of preoperative investigations, pathology at surgery and post-operative seizure outcome. All patients had transcortical SAH. Intraoperative MR imaging was used to assess the extent of mesial resection at the time of surgery. Seizure outcomes were assessed using the Engel classification. Results: Eighty-five patients were identified. The mean age at onset of epilepsy was 14.5 yrs and mean duration of epilepsy prior to surgery was 22 yrs. Mesial temporal sclerosis was identified on MRI in 77 % of patients. Seventy two percent of of patients were free of seizure free with a mean follow up of 25 months. Reasons for failure included subtle lesions identified outside of the selective resection,a neocortical temporal and orbitofrontal FCD, bitemporal epilepsy and misdiagnosis of MTLE. Serious permanent complications occurred in three patients. Conclusions: Selective amygdalohippocampectomy is a safe procedure which provides good seizure control in the majority of patients with intractable MTLE. Care must be taken in the selection of these patients to avoid a misdiagnosis of MTLE which may result in unnecessary surgical failure