A retrospective analysis of the effects of magnet-activated stimulation in conjunction with vagus nerve stimulation therapy

Epilepsy Behav. 2003 Dec;4(6):740-5. doi: 10.1016/j.yebeh.2003.08.025.


Vagus nerve stimulation (VNS) therapy offers two methods to help control seizures, automatic stimulation delivered at programmed intervals and on-demand stimulation initiated with a magnet. This study retrospectively analyzes magnet use during the E03 and E04 clinical trials of VNS therapy. Magnet activation that aborted, decreased, terminated, or diminished a seizure was classified as an improvement; for purposes of evaluation, the patient was considered to have received a benefit. When patients in the E03 trial used magnets to activate stimulation, patients with active magnets were more likely to report seizure improvement than patients with inactive magnets (P=0.0479, Fisher's test). In the E04 trial, 22% of patients using the magnet reported seizure termination and 31% reported seizure diminution. Unrelated to seizure reduction with programmed VNS therapy, approximately half of the patients who used the magnet in this study received some benefit. Additional studies can provide a better understanding of this unique mode of delivering antiseizure therapy.

Publication types

  • Comparative Study

MeSH terms

  • Anticonvulsants / therapeutic use
  • Dose-Response Relationship, Radiation
  • Double-Blind Method
  • Electric Stimulation / methods*
  • Electric Stimulation Therapy / methods*
  • Humans
  • Longitudinal Studies
  • Magnetics*
  • Randomized Controlled Trials as Topic
  • Retrospective Studies
  • Seizures / therapy*
  • Severity of Illness Index
  • Statistics, Nonparametric
  • Time Factors
  • Treatment Outcome
  • Vagus Nerve / physiopathology
  • Vagus Nerve / radiation effects*


  • Anticonvulsants