A Prospective Study of the Utility of Neurophysiologic Intraoperative Monitoring by Stereotactic Depth Electrodes During MRI-guided Laser-interstitial Thermal Therapy for Refractory Mesial Temporal Lobe Epilepsy

Mesial temporal lobe epilepsy (MTLE) is the most common cause of medication-resistant epilepsy in adults, and MRI-guided laser interstitial thermal therapy is a new approach to its surgical management; however, while LITT demonstrates fewer complications than traditional surgical techniques, it generates lower rates of seizure freedom. During traditional temporal lobectomy for MTLE, neurophysiologic intraoperative monitoring (NIOM) can be used to better identify epileptogenic tissue and guide resection. Our study proposes to investigate the utility of NIOM during LITT for MTLE. Subjects will be drawn from refractory mesial temporal lobe epilepsy patients determined to be candidates for LITT. During their LITT surgery, in addition to the placement of the stereotactic LITT probe, subjects will receive a second smaller stereotactic electrode for intraoperative monitoring of epileptic discharges before and after surgery. After surgery, at regularly scheduled follow-ups, patients will receive the Quality of Life in Epilepsy questionnaire (QOLIE-31-P), in addition to standard post-operative care. Endpoints will be surgical complications, fractional decrement in epileptiform discharges from pre- to post-ablation recordings, and surgical outcome at 6 months and one year. Analysis of severe complications will be expressed as a simple complication rate, for overall complications, severe complications, and hemorrhagic complications in specific. The relationship between fractional discharge decrement and outcome will be assessed by regression analysis. Risks of the study will stem from the placement of the stereotactic electrode for intraoperative monitoring, which represents a small incremental risk beyond typical LITT for MTLE.