Effect of bihemispheric anodal transcranial direct current stimulation for dysphagia in chronic stroke patients: A randomized clinical trial

To investigate whether bihemispheric anodal transcranial direct current stimulation (tDCS) with conventional dysphagia therapy could improve swallowing function in chronic stroke patients with dysphagia. Randomized controlled trial. Twenty-six patients with dysphagia for at least 6 months post-stroke were randomly assigned into: (i) bihemispheric anodal tDCS group; or (ii) sham group. All patients underwent 10 tDCS sessions with simultaneous conventional swallowing therapy for 2 weeks. Both anodal electrodes were attached bilaterally to the pharyngeal motor cortices, and cathodal electrodes were attached to both supraorbital regions. Swallowing function was evaluated with the Dysphagia Outcome and Severity Scale (DOSS) before and immediately after the last intervention session. The bihemispheric anodal tDCS group showed a mean significant improvement 0.62 points; standard deviation (SD) 0.77, in the DOSS immediately after all sessions (p = 0.02). However, there was no mean significant improvement in the sham group (0.38 points; SD 0.65(p = 0.06)). There was no significant difference between the 2 groups (p = 0.48). The bihemispheric anodal tDCS with conventional dysphagia therapy had additional helpful effects on the improvement in swallowing function in chronic stroke patients.