Three-Day Bi-Hemispheric tDCS With Motor Training Shows No Improvement in Pianist's With Musician's Dystonia: A Pilot Study.

Focal hand dystonia in musicians is a task-specific movement disorder that can impair professional performance, and effective rehabilitative treatments remain limited. Prior work suggested that bi-hemispheric transcranial direct current stimulation (tDCS) paired with bimanual mirror-movement training may transiently improve fine motor control in affected pianists. This case-control pilot study tested whether extending this approach to three consecutive days would produce detectable and sustained benefit. Ten professional pianists with unilateral musician's dystonia and 10 matched healthy pianists received 30 min of bi-hemispheric tDCS over sensorimotor cortices while performing bimanual mirrored finger exercises on three consecutive days, with follow-up assessment 10 days later. After exclusions, analyses included eight patients and eight controls for Musical Instrument Digital Interface-based motor outcomes and six patients and eight controls for video ratings. As anticipated, dystonia patients showed poorer temporal motor control and lower subjective performance ratings than controls. However, the protocol did not produce significant group-level improvement in objective motor performance, expert-rated movement impairment or regularity, or subjective performance, nor was benefit retained at 10 days. Video ratings of movement impairment showed acceptable reliability, whereas regularity ratings did not. These findings do not support detectable efficacy of this consecutive-day protocol under the present conditions and highlight the need for larger randomized, sham-controlled studies.