Vagal nerve stimulation in Dravet syndrome

Maxine Dibué-Adjei, Maxine Dibué-Adjei, Igor Fischer, Hans-Jakob Steiger, Marcel Alexander Kamp.  Efficacy of Adjunctive Vagus Nerve Stimulation in Patients with Dravet Syndrome: A Meta-Analysis of 68 Patients.  Seizure.  In press.

Highlights

•13 studies comprising 68 patients report efficacy of VNS in Dravet syndrome.

•52.9% of DS patients experienced a ≥50% reduction of seizures.

•Average seizure reduction, assessed in n = 28 patients was 50.8%.

Abstract

Rationale

Dravet Syndrome (DS) is a severe epileptic encephalopathy of childhood involving intractable seizures, recurrent status epilepticus and cognitive decline. Because DS is a rare disease, available data is limited and evidence-based treatment guidelines are lacking. Vagus nerve stimulation (VNS) is an established neurostimulation treatment for intractable epilepsy, however little evidence is published on its efficacy in patients with DS.

Methods

We performed a meta-analysis of all peer-reviewed English language studies reporting seizure outcomes of patients with DS treated with adjunctive vagus nerve stimulation. The primary and secondary outcome measures were ≥50% reduction of seizures or of the most-debilitating seizure type and seizure reduction per patient.

Results

13 studies comprising 68 patients met the inclusion criteria of which 11 were single-center retrospective case series, one was a multi-center retrospective analysis and one was a case report. 52.9% of patients experienced a ≥50% reduction of seizures and the average seizure reduction, which could only be assessed in n = 28 patients was 50.8%. 7 out of 13 studies reported additional benefits of VNS, however this could not be assessed systematically.

Conclusion

Vagus nerve stimulation appears to reduce seizure frequency in patients with DS. Based on this preliminary analysis, controlled trials of VNS in this rare condition using patient-centric outcome measures are indicated.