Seizure and neuropsychological outcomes in a large series of selective amygdalohippocampectomies with a minimally invasive subtemporal approach

OBJECTIVE Debate continues over proper surgical treatment for mesial temporal lobe epilepsy (MTLE). Few large comprehensive studies exist that have examined outcomes for the subtemporal selective amygdalohippocampectomy (sSAH) approach. This study describes a minimally invasive technique for sSAH and examines seizure and neuropsychological outcomes in a large series of patients who underwent sSAH for MTLE. METHODS Data for 152 patients (94 women, 61.8%; 58 men, 38.2%) who underwent sSAH performed by a single surgeon were retrospectively reviewed. The sSAH technique involves a small, minimally invasive opening and preserves the anterolateral temporal lobe and the temporal stem. RESULTS All patients in the study had at least 1 year of follow-up (mean [SD] 4.52 [2.57] years), of whom 57.9% (88/152) had Engel class I seizure outcomes. Of the patients with at least 2 years of follow-up (mean [SD] 5.2 [2.36] years), 56.5% (70/124) had Engel class I seizure outcomes. Preoperative and postoperative neuropsychological test results indicated no significant change in intelligence, verbal comprehension, perceptual reasoning, attention and processing, cognitive flexibility, visuospatial memory, or mood. There was a significant change in word retrieval regardless of the side of surgery and a significant change in verbal memory in patients who underwent dominant-side resection (p < 0.05). Complication rates were low, with a 1.3% (2/152) permanent morbidity rate and 0.0% mortality rate. CONCLUSIONS This study reports a large series of patients who have undergone sSAH, with a comprehensive presentation of a minimally invasive technique. The sSAH approach described in this study appears to be a safe, effective, minimally invasive technique for the treatment of MTLE.