Abstracts

Rationale: Stereotactic laser amygdalohippocampotomy (SLAH) produces superior cognitive outcomes as compared to selective and standard open resection (OR) procedures in the treatment of mesial temporal lobe (TL) epilepsy, while producing nearly equivalent rates of seizure freedom. We examined changes in functional status, presuming that the preservation of cognitive skills would be best manifest in real-world settings. Methods: We compared functional outcome status in a series of SLAH patients (n=53) and a near-consecutive sample of OR patients (n=20) undergoing surgery at the Emory University Epilepsy Center. We used a hierarchical classification of functional status based on the following criteria: 1) employed and independent with all activities of daily living (ADLs), 2) unemployed and independent with all ADLs, 3) unemployed and independent with lower ADLs only (i.e., independent with self-care, but not with management of finances, medications, etc.), & 4) unemployed and unable to manage any ADLs without assistance. All subjects were rated on these criteria at both baseline and one-year post-surgical time points, and were classified as improving, declining, or remaining stable in functional status. These proportional ratings of change were then compared between surgical procedures using Fisher’s exact test. Results: Both surgical groups had equivalent proportions of patients in each functional rating classification at baseline. However, the SLAH group had significantly more patients improve in functional status (13.2% vs. 0%) and fewer patients decline than did the OR group (3.7% vs. 35%, Fisher’s exact test: p=0.0012). Importantly, functional status correlated strongly with global ratings of neurocognitive change but not with seizure freedom status. SLAH patients were less likely to experience a decline in employment status than were OR patients (i.e., 5/11 [45.4%] of the OR sample employed at the time of surgery lost their jobs following surgery while only 1/24 [4.2%] of the employed SLAH patients declined on this variable), Fisher’s exact test, p=0.0062. Conclusions: Functional outcome was significantly better for patients undergoing SLAH than OR procedures for the surgical treatment of epilepsy, with improvement in functional status strongly associated with improvements in global cognitive performance. This study provides a real-world metric of meaningful change following surgery, which is, critically, independent of seizure freedom outcome. Funding: R01 NS088748K02 NS070960Medtronic, Inc.