Intensive Rehabilitation With Adjunctive Bilateral Anodal tDCS in Post‐Stroke Dysphagia: A Multicenter Randomized Controlled Trial

Background: Oropharyngeal dysphagia is a common and disabling consequence of stroke. Transcranial direct current stimulation (tDCS) has shown potential in promoting swallowing recovery, although evidence remains limited. Objective: To determine whether bilateral anodal tDCS combined with intensive speech-language therapy (SLT) improves swallowing outcomes compared with sham stimulation in patients with post-stroke dysphagia. Exploratory analyses examined the influence of treatment phase, sex, lesion site, and baseline severity. Methods: This multicenter, randomized, double-blind, sham-controlled trial enrolled patients with supratentorial or infratentorial ischemic stroke and oropharyngeal dysphagia. Participants received either bilateral anodal tDCS or sham stimulation (1.5 mA, 20 min/day, 5 days/week for 2 weeks) combined with intensive SLT over 6 weeks. Swallowing outcomes were assessed at baseline, 2 weeks, and 6 weeks using the Dysphagia Outcome and Severity Scale (DOSS, primary outcome), Penetration–Aspiration Scale (PAS), Mann Assessment of Swallowing Ability (MASA), and Swallowing Quality of Life questionnaire (SWAL-QoL). Results: Forty-six patients (24 active, 22 sham) completed the protocol. Both groups showed significant improvement across all outcomes (p < 0.001), with no significant difference between active and sham stimulation. The DOSS was the most sensitive measure, showing sustained improvement over time. Exploratory analyses indicated greater MASA gains with active tDCS in infratentorial strokes (p = 0.04). Correlation analyses showed that greater baseline dysphagia severity was associated with larger functional gains. Conclusions: Intensive SLT was associated with meaningful recovery in post-stroke dysphagia, regardless of stimulation condition. Exploratory findings suggest that bilateral tDCS may confer additional benefit in selected lesion subgroups.