Introduction: Temporal lobe epilepsy (TLE) localized to encephalocele is a phenomenon infrequently described in literature and largely discovered intraoperatively. We provide a six patient, single-center series with TLE localized to a middle cranial fossa encephalocele. This abstract delineates individual patient characteristics and rationale for surgical approach.
Methods: Patients with temporal lobe epilepsy and concurrent temporal encephalocele were identified via patient database and retrospectively reviewed. Demographics, seizure semiology, electroencephalography, neuropsychiatric findings, and imaging were compiled from the comprehensive epilepsy evaluation performed at our institution.
Results: Six patients were identified with seizures localized to encephalocele discovered on preoperative MRI. Three had EEG lateralization to left, one to right, and two bitemporal. Five of six patients underwent craniotomy for epilepsy. One patient had vagal nerve stimulator. Two patients had standard right anterior temporal lobectomy. Two patients had left hippocampal and amygdala sparing temporal lobectomy. One patient had left temporal pole encephalocele resection. All patients undergoing craniotomy achieved Engel I seizure freedom at time of last follow up.
Conclusions: Engel I seizure freedom may be achieved through simple resection of encephalocele and surrounding gliotic tissue. Those at high risk of developing neurologic impairment from standard temporal lobectomy as determined by neuropsychiatric testing and/or functional MRI should be considered for this surgical approach.
TLE owing to middle fossa encephalocele may be a more frequent finding than previously reported. High resolution CT or thin-cut sequences on MRI in temporal lobe epilepsy may be useful in preoperative discovery and may alter surgical decision making.
Patient Care: This research reveals that temporal lobe encephalocele may be a more common entity than is reported. If encephalocele resection provides equal seizure freedom as a larger temporal lobectomy with hippocampectomy, this change in surgical approach can reduce morbidity associated with larger temporal lobe resections.
Learning Objectives: By the conclusion of this session, participants should be able to:
1. Understand the importance of perioperative evaluation for surgical management of temporal lobe epilepsy.
2. Discuss the potential difference in neuropsychiatric outcome in patients with simple encephalocele resection versus temporal lobectomy with amygdalohippocampectomy.
3. Identify patients with complex partial seizure who are potential surgical candidates.