Anodal transcranial direct current stimulation in early rehabilitation of patients with post-stroke non-fluent aphasia: A randomized, double-blind, sham-controlled pilot study

Purpose: Recent research in patients with chronic aphasia shows an association between excitatory anodal transcranial direct current stimulation (A-tDCS) of the stroke-affected left hemisphere coupled with speech and language therapy (SLT) and better language performance. The present study aimed to investigate this association during the early post-stroke rehabilitation period, when adaptive changes are most possible on neurophysiological and behavioral levels. Methods: We randomized 24 patients with non-fluent aphasia to receive 15 consecutive sessions (5 days/week for 3 weeks) of A-tDCS (1 mA, 10 min; n = 14) or sham tDCS (S-tDCS: 1 mA, 25 sec; n = 10) over Broca's area followed by 45-min SLT. Naming ability was assessed before the rehabilitation, after its completion, and three months later. Results: Both groups significantly improved after the therapy. There were no statistically significant between-group differences in the short-term or long-term tDCS effects on naming accuracy and naming time. The A-tDCS group obtained higher effect sizes in naming time, both post-treatment and at the 3-month follow-up, suggesting potential benefits of the stimulation. Conclusions: The findings provide only weak evidence for A-tDCS-related language gains during early neurorehabilitation of post-stroke aphasia. Further research is needed to explore the effectiveness of this kind of neuromodulation.