Abstracts

Vagal Nerve Stimulation for Drug-Resistant Absence Epilepsy

Abstract number : 2.154
Submission category : 4. Clinical Epilepsy / 4C. Clinical Treatments
Year : 2023
Submission ID : 548
Source : www.aesnet.org
Presentation date : 12/3/2023 12:00:00 AM
Published date :

Authors :
Presenting Author: Caitlin Wessel, BS – University of Louisville

Feride Un Candan, BS – Division of Child Neurology – Norton Children's Hospital; Paya Yazdanpah, BS – University of Louisville; Samir Karia, MD – Division of Child Neurology – Norton Children's Hospital; Ian Mutchnick, MS, MD – Department of Neurosurgery – University of Louisville; Jeetendra Sah, MD – Division of Child Neurology – Norton Children's Hospital; Cemal Karakas, MD – Division of Child Neurology – Norton Children's Hospital

Rationale: Absence epilepsy syndromes have a high likelihood of resolving adulthood. However, 11% of patients develop drug-resistant absence epilepsy (DRAE) while another 15% of them progress to having either generalized tonic-clonic or myoclonic seizures. Children with DRAE are at increased risk for developing executive and speech dysfunction as well as ADHD and there are currently no therapeutic recommendations for DRAE. The purpose of this retrospective study was to assess the efficacy of vagus nerve stimulation (VNS), along with the appropriate medical management, in treating DRAE at our institution.

Methods: Patients were retrospectively identified in the Norton Children’s Hospital VNS surgery database between 2010 and 2022. All subjects were less than 18 years of age at seizure onset, were electroclinically diagnosed with an absence epilepsy syndrome (childhood, juvenile, or Jeavons syndrome) with absence seizures as their primary seizure type, and had a normal brain MRI. The primary outcome measure was post-VNS seizure frequency.

Results: Twenty-six patients (M/F: 14/12) were identified with an average age of seizure onset of 6.9 years (SD: +3.6; range 13mo-13yrs). Fourteen patients met criteria for Childhood Absence Epilepsy, six for Juvenile Absence Epilepsy, and six with Jeavons Syndrome. Patients had an average of 6.5 seizure days (+1.5) per week, and there was no significant difference in seizure frequency between males and females (p=0.52). The average age at VNS implantation was 13.3yr (+3.9; range 2.7yr-18.6yrs), with patients experiencing seizures for an average of 6.4yrs (+3.5) of seizures prior to VNS. The average time from failing a second ASM to VNS implant was 4.7 years (+2.1) and patients failed an average of 5 (+2) anti-seizure medications (ASM) prior to VNS implant. However there was no significant correlation between the time to VNS from medical refractoriness and the degree of seizure reduction (p=0.067). The average follow up duration was 5.0 years (+3.8) after VNS implant, with patients reporting an average of 2.2 seizure days (+2.6) per week. After any necessary revisions, the median final VNS current output was 1.75mA (range: 0.25-2.5) with a median stimulation frequency of 22.5Hz (range: 20-30). A total of 80% of patients reported a greater than or equal to 50% reduction in seizure frequency (p< 0.001), regardless of implant age (p=0.29) or time from seizure onset to VNS implant (p=0.80).
Clinical Epilepsy