Effects of Acute Transcranial Direct Current Stimulation on Gait Kinematics of Individuals With Parkinson Disease

Abstract

Background: One of the most disabling problems in Parkinson disease (PD) is gait impairment. Noninvasive brain stimulation techniques, such as transcranial direct current stimulation (tDCS), have been introduced as a therapeutic alternative for coping with PD motor problems. However, the effects of tDCS on gait performance in PD have not yet been fully established. Therefore, the main objective of this study was to evaluate whether a single session of tDCS modifies gait kinematics in individuals with PD. Methods: Twenty-one individuals with PD were included in this randomized, double-blinded, sham-controlled design study. They were randomly allocated in one real (N = 8) or sham (N = 9) tDCS group. Real tDCS comprises a 2-mA anodic current applied over 15 minutes in the supplementary motor area and medial areas of the primary motor cortices through a bipolar electrode montage. Gait kinematics and the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) were assessed before and immediately after a single stimulation session. Pre- minus poststimulation (Δ) values were computed and compared through a Mann-Whitney test. Data are shown as the median (lower, upper quartile). Results: There was a significant group difference with a large effect size for Δ values of gait cadence (P = .014, d = 0.87), indicating its reduction after anodic stimulation in the real (−0.28 [−1.16, 0.01] steps/s) compared with sham tDCS group (0.17 [0.00, 0.40] steps/s). No other significant effect was found. Conclusion: The findings of this study suggest that anodic tDCS administered in a single session improves gait cadence in PD individuals.