Acute effects of transcranial direct current stimulation combined with physical therapy on the balance and gait in individuals with Parkinson's disease: A randomized controlled trial.

Application methods of transcranial direct current stimulation (tDCS) in Parkinson's disease (PD) are quite divergent making it difficult to define the clinical effectiveness of the tDCS on PD. Thus, the aim of this study was to verify the acute effects of tDCS when applied to different targets (Cz or C3-Cz-C4) combined to physical therapy to improve balance and gait in individuals with PD. A randomized controlled trial was conducted, with 50 individuals who were separated into four groups: 1) Real tDCS (Cz) + physical therapy, 2) Real tDCS (C3-Cz-C4) + physical therapy, 3) Sham tDCS + physical therapy and 4) Educational lecture + physical therapy. The current intensity was 2 mA, applied for 20 min. For the instrumental assessment of balance and gait, the 3D motion analysis system was used. For the biomechanical analysis of gait, three different conditions were performed: normal gait, dual task gait and obstacle gait. For balance analysis, the following positions were utilized: Romberg with eyes opened, Romberg with eyes closed, Tandem with eyes opened and Tandem with eyes closed. All evaluations were performed pre-intervention, post-intervention (immediately at the end of the intervention) and were followed-up on (24 h after the end of the intervention). No statistically significant differences were found for all gait and balance outcomes when considering the interaction between time (pre, post and follow-up assessments) versus group (Education, Sham, Cz and C3-Cz-C4). In conclusion, it was found that one session of tDCS, stimulating Cz or C3-Cz-C4 combined with physical therapy, was not effective in improving the balance and gait in people with PD as compared to sham tDCS or educational lecture plus physiotherapy.