Abstracts

Rationale: Although anterior mesial resection and selective amygdalohippocampectomy are highly effective for mesial temporal lobe epilepsy (MTLE), they are highly invasive surgical procedures that can be associated with complications including neurocognitive deficits. Stereotactic laser amygdalohippocampotomy (SLAH) is a minimally-invasive alternative performed using laser-interstitial thermal therapy (LITT) that may eliminate seizures with lower morbidity and decreased length of stay and recovery. Here we report retrospective results at 6 months from all 41 patients with MTLE who underwent SLAH at 13 epilepsy centers.Methods: SLAH was performed by LITT with a computer-based real-time MRI-thermometry control system following stereotactic insertion of a saline-cooled optical fiber along the long axis of the amygdalohippocampal complex. 68 patients with MTLE age 7 75 (39 15) underwent 70 SLAH procedures. MRI was normal in 7, otherwise showing mesial temporal sclerosis, atrophy, gliosis, or DNET in 1 case. A subset of patients underwent extensive neuropsychological assessments.Results: Forty-one patients have reached their 6 month post-operative follow-up: 22 (54%) are seizure-free (Engel 1), 2 (5%) have rare seizures (Engel II), and 8 (20%) have worthwhile improvement (Engel III). Adverse effects in the entire cohort of 68 patients included visual field cuts (n=9; 13%), only one of which was a homonymous hemianopia, and many of which are improving; hemorrhage (n=4; 6%), two of which were symptomatic with visual field cuts that are improving; one hospitalization for seizures and one suicide attempt unrelated to surgery. Conclusions: SLAH is a minimally-invasive alternative to open resection in patients with MTLE. Six-month outcomes are highly predictive of 12-month results, which will be available at this presentation, as will 6-month outcomes on the whole cohort. Seizure-free rates might be expected to improve with increased experience with this novel technique. Neuropsychological assessments, which show fewer deficits than open surgery in a limited cohort thus far analyzed, will also be presented.