Radiofrequency thermocoagulation in focal epilepsy: A retrospective cohort study.

Abstract

Objective: Stereoelectroencephalography-guided radiofrequency thermocoagulation (SEEG-guided RFTC) has been increasingly used as diagnostic and therapeutic approach for drug-resistant focal epilepsies (DREs). We aimed to describe seizure outcomes of RFTC before and after further neurosurgical intervention.

Methods: Retrospective single-institution case series of patients who underwent SEEG-RFTC. The primary outcome was Engel class I-IV classification ([responders Engel I-III and non-responders Engel IV]) at last follow-up after RFTC and prior to further neurosurgical intervention (open surgical resection, laser ablation, and neuromodulation).

Results: Twenty-five patients (median age 18.9 years) with DRE were included. The median follow-up time after RFTC was 7.2 months, including 20 patients who underwent further intervention (median follow-up time of 7.3 months) and 5 without intervention (median of 3.5 months). From the patients who had further intervention, 17 (85%) underwent surgical procedure (laser ablation 53%, open surgical resection 47%) (median 4.4 months) and 3 (15%) had responsive neurostimulators placed (median 6.9 months). Prior to further intervention (median follow-up 3.5 months after RFTC), 12 (48%) patients were classified as responders (12% Engel class I, 16% class II, and 20% class III) and 13 (52%) as non-responders. Following neurosurgical intervention, 17 (68%) patients were followed for a median time of 2.7 months and 3 were lost to follow-up. Of eight initial RFTC responders, 87.5% and 12.5% had Engel classes I and III, respectively. Of nine who were non-responders, 33% had Engel class I, 22% II and III, and 44% IV outcomes following further intervention. No neurologic complications were reported.

Significance: SEEG-guided RFTC is a well-tolerated procedure and a beneficial diagnostic approach prior to further neurosurgical interventions in patients with DRE.

Plain language summary: SEEG-guided RFTC is a well-tolerated procedure and in the patients who experienced initial seizure reduction (n = 8), subsequent neurosurgical intervention (surgery or neuromodulation) led to favorable seizure outcomes (87.5% seizure freedom and 12.5% worthwhile seizure improvement).