Effects of transcranial direct current stimulation on dysphagia arising from bulbar or pseudobulbar palsy after stroke

Abstract

Objective To explore the clinical effect of applying transcranial direct current stimulation (tDCS) to stroke survivors with dysphagia caused by bulbar or pseudobulbar palsy. Methods Sixty stroke survivors with dysphagia caused by bulbar or pseudobulbar palsy were randomly divided into an experimental group and a control group, each of 30. All were given basic rehabilitation training, including cold stimulation of the pharynx and empty swallowing training twice a day, practicing the pronunciation of the sounds A, YI and WU five times a day, 30 to 60 repetitions of tongue aspirator training daily and three 15-minute massages with an electric toothbrush. Each subject also received 20 minutes of treatment with a Vocastim swallowing therapy apparatus every day, six times a week for two weeks. Those in the experimental group also received 20 minutes of tDCS every day, six times a week during the two weeks. Before and after the treatment, all were evaluated using the Kubota drinking water test, a functional oral intake scale (FOIS) and standardized swallowing assessment (SSA). Results After the treatment, a significant improvement was observed in the average Kubata test scores, with the improvement of the experimental group significantly greater than that of the control group. The average FOIS score of those with pseudobulbar palsy in both groups also improved significantly, with the experimental group′s average significantly better than that of the control group. The average FOIS scores of those with bulbar palsy had also improved significantly, but there was no significant inter-group difference. The average SSA scores of those with pseudobulbar palsy in both groups improved significantly, with significantly greater improvement in the experimental group. The average scores of those with bulbar palsy decreased significantly, but without significant inter-group differences. Conclusions Transcranial direct current stimulation can usefully supplement basic swallowing training, especially for those with pseudobulbar palsy. Key words: Stroke rehabilitation; Transcranial direct current stimulation; Dysphagia; Bulbar palsy; Pseudobulbar palsy