P-TS005. Potential of transcranial direct current stimulation in modulating spinal reflex excitability in persons with chronic stroke

Abstract

Introduction. Stroke is the main cause of disability in adults living in developing countries. Spasticity is a primary impairment of stroke with an effect on the activities of daily life. Neural changes of the paretic limb often occur following spasticity. The aim of this study was to investigate the effect of Transcranial Direct Current Stimulation on neural properties of the spastic muscle in patients with chronic stroke. Methods. In this study double-blinded trial 22 participants with >6 months after stroke were randomized into two groups: active anodal or sham tDCS. The subjects in the experimental group participated in active tDCS and balance training program of 5 sessions. Evaluation performed at baseline and at the end of the intervention. Hmax/Mmax ratio and H-reflex latency were assumed. Clinical assessment was conducted using the Modified Ashworth Scale (MAS), Timed Up and Go (TUG), as well as the Timed 10-Meter Walk Test (10MWT). Repeated measure analysis of variance was used in the analysis. Friedman test in SPSS version 22.0 was used to analysis the response of ordinal variable in different stages of evaluation. Results. The active tDCS group showed significant differences in the Hmax/Mmax (P<0.005), 10MWT (P<0.01) Scale from sham subjects. Also, the latency of the H response from the stimulation was increased for the experimental patients compared to sham. Time by group interaction in the 10MWT, Hmax/Mmax ratio and H-reflex latency was significant. Nevertheless, there were no significant differences in the TUG (P=0.30) scores. The results indicated that the H-reflex latency, Hmax/Mmax ratio were altered after a-tDCS intervention which is correlated with improvement in walking outcome. Conclusion. The findings of the study illustrate that tDCS treatment with balance training can improve reflexes, and walking capacity in chronic stroke and can be considered as a promising therapeutic tool in rehabilitation setting.