Transcranial direct current stimulation over the vagus nerve promotes post-stroke dysphagia recovery: a randomized, double-blind, sham-controlled clinical trial

Objective To confirm whether transcranial direct current stimulation over the vagus nerve (VN-tDCS) can improve swallowing function in patients with post-stroke dysphagia. Design Parallel-group, randomized, double-blind, sham-controlled clinical trial. Methods Sixty-four patients with post-stroke dysphagia were randomly allocated to receive real or sham VN-tDCS combined with routine swallowing rehabilitation therapy. Swallowing function was assessed by Fiberoptic Endoscopic Dysphagia Severity Scale, Modified Mann Assessment of Swallowing Ability Scale, Functional Communication Measure and Rosenbek Penetration-Aspiration Scale before and after treatment. Results After 4 weeks of treatment, swallowing function improved in both the VN-tDCS group and control group. Intragroup changes in the Fiberoptic Endoscopic Dysphagia Severity Scale, Modified Mann Assessment of Swallowing Ability Scale, Functional Communication Measure, and Rosenbek Penetration-Aspiration Scale scores were more significant in the VN-tDCS group than in the control group. Conclusions This preliminary study suggested that the performance of VN-tDCS improved the swallowing function in patients with post-stroke dysphagia and extended the clinical application of transcranial direct current stimulation in post-stroke dysphagia.