Comparative Outcomes of Anterior Temporal Lobectomy versus Laser Ablation in a Single-Institutional Cohort with Temporal Lobe Epilepsy

Introduction: Anterior temporal lobectomy with amygdalohippocampectomy(ATL+AH) and laser ablation(LITT) are effective surgical approaches for drug-resistant temporal lobe epilepsy(TLE). A clinical priority is maximizing seizure freedom potential while preserving cognitive functioning. Here, we directly compare cognitive and seizure outcomes in a large cohort of TLE patients who underwent surgery by a single neurosurgeon.

Methods: 178 patients(18-70 years) underwent ATL+AH(n=118) or LITT(n=60). ILAE classification was used to score post-operative seizure outcomes. Pre-and post-operative neuropsychological testing were used to assess cognitive outcomes related to language and verbal memory(VM). Surgical and cognitive outcomes were also evaluated in a patient subset who underwent failed LITT and returned for ATL+AH(n=6). In an extended cohort of left language-dominant patients who underwent any type of epilepsy surgery in the temporal lobe(n=217), multivariate voxel-based lesion-symptom mapping(VLSM) was used to localize brain regions associated with language and VM declines.

Results: After one year, 65% of LITT and ATL+AH patients achieved complete seizure freedom. After three years, 50% of LITT and 65% of ATL+AH patients were seizure-free. In the failed LITT with subsequent ATL+AH cohort, 4 patients were seizure-free after ATL+AH. Naming declines were smaller in the language-dominant hemisphere following LITT compared to ATL+AH(p < 0.05). VM declines were greater in the language-dominant hemisphere compared to the non-dominant hemisphere for ATL+AH patients(p < 0.05). VLSM localized naming to the left language-dominant fusiform gyrus and VM to the left language-dominant hippocampus. Significant clusters for naming and VM had minimal overlap(14.7%) and were primarily located within the parahippocampal gyrus.

Conclusion : Our results indicate that seizure outcomes were comparable across interventions at one year. However, long-term outcomes suggest ATL+AH offers longer-lasting seizure control. Furthermore, naming and VM declines were greater for surgeries in the language-dominant hemisphere. Yet, these declines in naming were less pronounced with LITT, likely due to the preservation of naming-related sites in the fusiform gyrus.