AUTHOR=Taud Benedikt , Lindenberg Robert , Darkow Robert , Wevers Jasmin , Höfflin Dorothee , Grittner Ulrike , Meinzer Marcus , Flöel Agnes 

TITLE=Limited Add-On Effects of Unilateral and Bilateral Transcranial Direct Current Stimulation on Visuo-Motor Grip Force Tracking Task Training Outcome in Chronic Stroke. A Randomized Controlled Trial

JOURNAL=Frontiers in Neurology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.736075

DOI=10.3389/fneur.2021.736075

ISSN=1664-2295

ABSTRACT=<p><bold>Background:</bold> This randomized controlled trial investigated if uni- and bihemispheric transcranial direct current stimulation (tDCS) of the motor cortex can enhance the effects of visuo-motor grip force tracking task training and transfer to clinical assessments of upper extremity motor function.</p><p><bold>Methods:</bold> In a randomized, double-blind, sham-controlled trial, 40 chronic stroke patients underwent 5 days of visuo-motor grip force tracking task training of the paretic hand with either unilateral or bilateral (<italic>N</italic> = 15/group) or placebo tDCS (<italic>N</italic> = 10). Immediate and long-term (3 months) effects on training outcome and motor recovery (Upper Extremity Fugl-Meyer, UE-FM, Wolf Motor Function Test, and WMFT) were investigated.</p><p><bold>Results:</bold> Trained task performance significantly improved independently of tDCS in a curvilinear fashion. In the anodal stimulation group UE-FM scores were higher than in the sham group at day 5 (adjusted mean difference: 2.6, 95%CI: 0.6–4.5, <italic>p</italic> = 0.010) and at 3 months follow up (adjusted mean difference: 2.8, 95%CI: 0.8–4.7, <italic>p</italic> = 0.006). Neither training alone, nor the combination of training and tDCS improved WMFT performance.</p><p><bold>Conclusions:</bold> Visuo-motor grip force tracking task training can facilitate recovery of upper extremity function. Only minimal add-on effects of anodal but not dual tDCS were observed.</p><p><bold>Clinical Trial Registration:</bold><ext-link ext-link-type="uri" xlink:href="https://clinicaltrials.gov/ct2/results?recrs=&amp;cond=&amp;term=NCT01969097&amp;cntry=&amp;state=&amp;city=&amp;dist=" xmlns:xlink="http://www.w3.org/1999/xlink">https://clinicaltrials.gov/ct2/results?recrs=&amp;cond=&amp;term=NCT01969097&amp;cntry=&amp;state=&amp;city=&amp;dist=</ext-link>, identifier: NCT01969097, retrospectively registered on 25/10/2013.</p>