Vagal Nerve Stimulation in Epilepsy: Experiences of Participants with Cognitive Deficits.

Introduction: The purpose of this study was to examine patients' experiences of vagal nerve stimulation (VNS) with a special interest in patients with cognitive deficit (CD). Materials and Methods: An open, retrospective study was conducted on 82 patients with pharmacoresistant epilepsy, who were treated with VNS for at least 10 months. Based on the inability to live independently, they were divided into two groups: patients with cognitive deficit (CD group) and patients without cognitive deficit (non-CD group). A specially designed questionnaire was used for semi-structured interviews about patients' experiences of VNS treatment. Results: Approximately one-third described a continuous reduction of seizure frequency of 50% or more and were regarded as responders. Fewer subjects in the CD group were responders than in the non-CD group. Approximately one-third of all subjects had no positive effect of VNS treatment. More CD patients described additional improvements and the most common were milder seizures and improved alertness. The most commonly reported adverse effect was hoarseness. Discussion: VNS treatment in patients without CD had better effect on seizure frequency reduction than in patients with CD, but many patients with CD reported other benefits from the treatment. Conclusion: Non-CD patients had higher seizure frequency reduction than CD patients during VNS treatment, but many CD patients described other benefits.