Rationale:
Radiofrequency ablation (RF) through stereo-electroencephalography (sEEG) electrodes has emerged as a diagnostic and therapeutic option for patients with drug-resistant epilepsy, offering timely and targeted disruption of the putative epileptogenic zone as determined though invasive intracranial monitoring, potentially with lower morbidity compared to traditional surgical resection. This study aims to evaluate the clinical outcomes of SEEG-guided RF ablation in a consecutive patient cohort at our institution.
Methods:
We retrospectively reviewed all patients who underwent SEEG-guided RFA at the University of South Florida/Tampa General Hospital between 26 July 2018 and 27 November 2024. The decision to offer RFA was made by consensus at a multidisciplinary epilepsy surgery conference, for those electrodes determined to be within the EZ based on neurophysiological criteria, and consent was obtained in all cases. Demographics, epilepsy characteristics, operative details, Engel class at last follow-up, and peri-operative complications were abstracted from the electronic health record. The primary endpoint was Engel class I outcome (seizure freedom or rare disabling seizures).Results:
Thirteen patients (median follow-up 18 months [IQR 7–43]) underwent RFTC. At baseline, 10 patients (77%) had focal seizures, and 3 (23%) bilateral focal/multifocal onsets. MRI identified structural lesions in 6 patients (46%), including schizencephaly in 2, periventricular nodular heterotopias in 1, focal cortical dysplasia (FCD) in 2, and post-infectious gliosis in 1 patient who underwent craniotomy for evacuation of an abscess. Three patients had undergone prior resection, including 2 with structural lesions (schizencephaly, oligodendroglioma). Overall, 7 patients (54%) achieved Engel I, 3 (23%) Engel III, and 3 (23%) Engel IV.
In patients with focal epilepsy, 7 of 10 patients (70%) achieved seizure freedom, with 4 of 5 (80%) of patients with MRI-negative focal epilepsy achieving Engel I outcomes. In multifocal or bilateral disease, Engel I was achieved in 0 of 3 patients (0%). Four patients underwent prior resection or vagus nerve stimulation, and none of these achieved Engel I outcomes following RFA. One patient underwent subsequent selective laser amygdalohippocampectomy due to persistent seizures and attained Engel I outcomes, and 1 patient with an Engel IV outcome underwent subsequent VNS placement with no additional improvement in seizures. No permanent neurological deficits occurred. Transient adverse events (38%) included small tract hemorrhage, language disturbance, cognitive slowing, dysarthria with ataxia, and headache, all resolving without intervention.
Conclusions:
SEEG-guided RFTC achieved seizure freedom in over half of treated patients, with particularly favorable results in MRI-negative focal epilepsy and limited benefit in multifocal or bilateral disease. The absence of permanent morbidity supports its use in eloquent or high-risk regions and as a bridge to definitive therapy. These findings reinforce RFTC as a safe, effective, and versatile tool in the modern surgical management of DRE.
Funding: No funding was received for this study.