Epilepsy patients with and without perceived benefit from vagus nerve stimulation: A long-term observational single center study

Eylert Brodtkorb; Christian Samsonsen; Jan V Jørgensen; Grethe Helde

doi:10.1016/j.seizure.2019.09.004

Epilepsy patients with and without perceived benefit from vagus nerve stimulation: A long-term observational single center study

Seizure. 2019 Nov:72:28-32. doi: 10.1016/j.seizure.2019.09.004. Epub 2019 Sep 19.

Authors

Eylert Brodtkorb¹, Christian Samsonsen², Jan V Jørgensen³, Grethe Helde⁴

Affiliations

¹ Department of Neurology and Clinical Neurophysiology, St. Olav University Hospital, Trondheim, Norway; Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: eylert.brodtkorb@ntnu.no.
² Department of Neurology and Clinical Neurophysiology, St. Olav University Hospital, Trondheim, Norway; Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: christian.samsonsen@stolav.no.
³ Department of Neurosurgery, St. Olav University Hospital, Trondheim, Norway. Electronic address: jan.jorgensen@stolav.no.
⁴ Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: grethe.helde@hotmail.com.

PMID: 31563121
DOI: 10.1016/j.seizure.2019.09.004

Abstract

Purpose: Vagus nerve stimulaton (VNS) has been used for adjunctive treatment of drug-resistant epilepsy for more than 25 years. The true efficacy has been debated, as blinded randomized controlled trials are unavailable. The aim of this study was to evaluate the patient-reported perceived benefit of VNS and to compare clinical characteristics of patients with and without benefit.

Methods: Observational study of all 43 adult patients receiving VNS for >2 years at one single center. Mean duration of treatment was 9 years. At inclusion, a semi-structured interview on VNS effectiveness was performed. In patients without benefit, the VNS was turned off. The outcome was evaluated after an observation period of one year.

Results: 21 patients (49%) reported no clear benefit and stopped VNS. Only one of them resumed treatment within one year. Patients without benefit had received more new antiepileptic drugs (AEDs) during VNS treatment than those reporting benefit (p = 0.05). Other differences between the two groups were not found. Ten patients (23%) had been seizure free >1 year at inclusion (5 in the benefit and 5 in the non-benefit group). Seizure control was attributed to the response of another new treatment in the majority of these patients.

Conclusion: Half of the patients had not perceived clear benefit from VNS, and all but one terminated VNS without worsening of seizures within one year. The true outcome of long-term VNS is difficult to assess in real-world practice. The effect may be overestimated due to confounding factors, particularly the common introduction of novel AEDs and the natural course of the disorder. Patients without perceived benefit from long-term VNS should not routinely remain on treatment and be subject to undue generator re-implantations.

Keywords: Antiepileptic drugs; Discontinuation; Epilepsy; Perceived benefit; Seizures; Vagus nerve stimulation.

Publication types

Observational Study

MeSH terms

Adult
Epilepsies, Partial / diagnosis*
Epilepsies, Partial / therapy*
Epilepsy, Generalized / diagnosis*
Epilepsy, Generalized / therapy*
Female
Follow-Up Studies
Humans
Male
Middle Aged
Time Factors
Vagus Nerve Stimulation / methods*
Vagus Nerve Stimulation / trends