Vagus Nerve Stimulation Paired With Mobility Training in Chronic Ischemic Stroke: A Case Report

Objective. The purpose of this case report is to describe pairing vagus nerve stimulation (VNS) with mobility training in an individual after stroke. Methods. A 53-year-old man with left hemiparesis 14.2 months after an ischemic stroke participated in a pilot study investigating the safety and feasibility of VNS paired with upper limb rehabilitation. In addition to upper limb impairment, the participant had impaired gait and wanted to improve his mobility. A single-subject design investigation of VNS paired with self-directed mobility training was conducted. Following the conclusion of the pilot study, the participant was instructed to complete daily sessions of self-activated VNS paired with walking or stationary biking. The 10-Meter Walk Test and timed distance (6-Minute Walk Test) were assessed at 4 baseline points and at 3 to 41 months after mobility training. Results. The participant had stable baseline values and was classified as a household ambulator with a quad cane. After VNS-paired mobility training, statistically significant improvements were observed in all measures, with the greatest improvements at 9 months exceeding the minimal detectable change: self-selected gait speed from 0.34 (standard deviation [SD] = 0.01) to 0.60 meters/second, fast gait speed from 0.37 (SD = 0.03) to 0.79 meters/second, and 6-Minute Walk Test distance from 106.91 (SD = 6.38) to 179.83 meters. The participant reported increased confidence and balance when walking. No falls or adverse events were reported. Conclusion. The participant demonstrated improved gait speed and timed distance after VNS-paired mobility training. Randomized, blinded trials are needed to determine treatment efficacy. Impact. This is the first documented case of VNS-paired mobility training in an individual with chronic poststroke gait impairments. VNS paired with mobility training may improve poststroke gait impairments.