Resident Physician University of Pittsburgh School of Medicine, Department of Neurological Surgery, Pittsburgh, PA, USA
Introduction: Conventional surgical treatment of drug-resistant temporal lobe epilepsy (TLE) has consisted of either the “standard” temporal lobectomy (resection of all temporal structures to a fixed distance from the temporal pole) or various selective approaches to mesial structures, including laser ablation. However, these selective approaches suffer from a seizure freedom-cognitive outcome tradeoff, with more selective approaches resulting in lower rates of seizure freedom. Here, we challenge this by utilizing an SEEG-guided approach that divides temporal explorations into four categories – mesial/lateral temporal, temporal/basal/occipital, anterior perisylvian, and perisylvian. Utilizing this framework, based on anatomo-electrical clinical correlations, we performed tailored, patient-specific temporal resections resulting in both a high rate of seizure freedom and improved cognitive outcomes.
Methods: In a cohort of 60 patients with drug-resistant TLE who underwent SEEG, we collected clinical/epilepsy history, neuroimaging, semiology, and analysis of the multidisciplinary patient management conference. Patients were divided into these 4 groups based on these data. Resection patterns of specific temporal structures was analyzed. Seizure outcomes and neuropsychological evaluation, including verbal (RAVLT) and visuospatial memory (ROCF) and picture naming (BNT), at 1 year were collected.
Results: 49 patients (82%) underwent tailored resection, while 7 (12%) underwent neuromodulation, without differences by classification (p=0.9). The amygdala was resected in 65% of cases, the hippocampal head in 59%, tail in 24%, entorhinal cortex in 63%, and temporal pole in 65%. Only 3 patients had conventional standard temporal lobectomies. Median resection volume was 30cc [22,40] (p=0.4 by classification). Engel I seizure freedom at 1 year was 73% (p=0.4 by classification), with verbal memory decline in 26% overall (36% left), 19% picture naming decline (29% left), and 8% visuospatial memory decline.
Conclusion : SEEG-guided appropriately selective temporal resections can spare temporal structures while maintaining high rates of seizure freedom, resulting in improved neurocognitive outcomes. The seizure freedom-cognition tradeoff may be resolved using this approach.
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