Abstracts

Rationale: Minimally invasive surgical procedures are growing in neurosurgery and stereotactic surgery has been developing fast since the birth of its concept in the 1940s (1). Radiofrequency thermocoagulation (RFTC) was reported in the literature for the treatment of behavioral disorders and epilepsy by stereotactically implanting a probe and connecting it to a radiofrequency generator that will create a lesion in the desired target (2). RFTC has been combined with the established stereotactic encephalography (SEEG) technique by Guenot et al (2004) to allow for radiofrequency ablation through implanted SEEG leads to create focal lesions in the epileptogenic zone as a palliative procedure in epilepsy patients for whom surgical intervention deemed not feasible (3). Further studies reported the diagnostic importance of SEEG-guided RFTC as a predictive therapeutic test before surgical resection (4,5). The aim of our study is to assess the efficacy and safety of SEEG-guided RFTC in fourteen patients with epilepsy at Children’s Hospital Colorado. To our knowledge, this is the first US-based report of SEEG-guided RFTC experience in pediatric patients with epilepsy.


Methods: After appropriate IRB approval, a single-center retrospective review was performed for patients with refractory epilepsy presenting to Children’s Hospital Colorado, US, from January 2020 to September 2022, for SEEG placement who underwent subsequent RF ablation prior to SEEG removal. For each patient, age, gender, semiology of seizures, number and location of SEEG electrodes, inpatient SEEG recordings, pre- and post- RF ablation EEG recordings, post-MRI findings, complications, Engel class, and length of hospitalization were collected.


Results: Fourteen patients with an average age of 12.3 + 5.3 years (10 female) underwent placement of an average of 11.75 + 2.6 leads for a median of 6 days before RF ablation. There was one complication of SEEG lead placement; one patient with undiagnosed Factor XIII deficiency had multifocal hemorrhage along each lead and postoperative aphasia (has not returned to baseline but improving 3 months postoperatively). One complication was noted after RFTA: return to emergency department for headache. Six of the 14 patients underwent secondary surgical treatment of epileptogenic focus. Follow up Engel classification yielded 5 patients in Engel class I, two in class II, two in class III, three in class IV, and two unclassified. Of note, one patient achieved Engel class I seizure freedom without further surgical intervention.


Conclusions: Our patient population tolerated RFTA treatment of epileptogenic foci without significant complications and one achieved Engel class I seizure freedom without further surgical intervention. RFTA along SEEG leads is safe in the pediatric population and may be an effective bridge to definitive surgical treatment of epileptogenic focus.


Funding: No funding was obtained for this study.