BACKGROUND: To improve functional performance of the affected upper limb (UL) after a stroke, strengthening exercises are beneficial. Since neurostimulation techniques, such as transcranial direct current stimulation (tDCS), can help boost therapy gains, the goal of this pilot study was to assess if the combination of tDCS with a strengthening program could further promote motor recovery in chronic stroke survivors.
METHODS: Thirteen volunteers (68±9 years; 75±57 months post-stroke) were randomized in a training/tDCS-real (n=6) or training/tDCS-sham (n=7) group. Participants trained their affected UL for 4 weeks (3X/week) while receiving tDCS (bihemispheric montage; 20 minutes; 1.5mA).  Motor recovery, functional performance and daily use of the affected UL (quantity/quality) were assessed pre/post-training using the Fugl-Meyer Assessment scale (FMA;/66), the Wolf Motor Function test (WFMT;/5) and the Motor Activity Log (MAL;/5), respectively. Non-parametric statistics were used to assess the impact of tDCS on post-exercise gains within and between groups.   
RESULTS: Only the tDCS-real group showed a significant improvement at the FMA (6±5, p=0.03) and WMFT (0.4±0.3, p=0.04). Both groups showed significant gains on the MAL qualitative score (tDCS-real 0.4±0.4, p=0.04; tDCS-sham 0.3±0.2, p=0.04). However, no significant difference was found between groups for any clinical gains.
DISCUSSION AND CONCLUSION: tDCS seems to boost exercise gains of the affected UL, but a greater sample size is needed to determine whether this effect is significantly greater than that of exercise alone. More studies are required to assess the use of tDCS post-stroke and to determine optimal tDCS parameter choices (e.g. montage, intensity).

COULD TRANSCRANIAL DIRECT CURRENT STIMULATION POTENTIATE THE EFFECT OF A STRENGHTHENING PROGRAM IN CHRONIC STROKE SURVIVORS? PRELIMINARY RESULTS