Vagus nerve stimulation for refractory epilepsy: a transatlantic experience

Area of Science:

• Neurology
• Neurosurgery
• Epileptology

Background:

• Epilepsy is a chronic neurological disorder characterized by recurrent seizures.
• Medically or surgically refractory epilepsy presents significant treatment challenges.
• Vagus nerve stimulation (VNS) is an established neuromodulatory therapy for difficult-to-treat epilepsy.

Purpose of the Study:

• To evaluate the long-term efficacy and safety of VNS in a large, multi-center patient series.
• To assess seizure frequency reduction and identify responder rates in patients with refractory epilepsy.
• To document and analyze stimulation-related side effects associated with VNS therapy.

Main Methods:

• Prospective assessment of seizure frequency, type, antiepileptic drug use, and side effects in 131 patients treated with VNS.
• Inclusion criteria required a minimum 6-month follow-up duration post-implantation.
• Data collected from Ghent University Hospital and Dartmouth-Hitchcock Medical Center between March 1995 and February 2003.

Main Results:

• A total of 118 patients met the inclusion criteria with a mean follow-up of 33 months.
• The mean reduction in monthly seizure frequency was 55% across all patients.
• Seven percent of patients achieved complete seizure freedom (impaired consciousness), 50% had >50% reduction, and 21% were non-responders. Fifteen patients reported mild side effects.

Conclusions:

• Vagus nerve stimulation (VNS) demonstrates long-term efficacy in reducing seizure frequency for patients with refractory epilepsy.
• VNS is a safe treatment option, with a low incidence of manageable stimulation-related side effects.
• Findings from two distinct continents confirm the generalizability and reliability of VNS therapy in epilepsy management.