Effects of transcranial direct current stimulation (tDCS) on gait asymmetry in people with Parkinson's disease

• Grant number: 25/06207-3
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2026
• End date: December 31, 2028
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Fabio Augusto Barbieri
• Grantee: Vinicius Cavassano Zampier
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil
• Associated research grant: 24/01132-2 - Multidisciplinary Center for the Development of Assistive Technology (MCDAT), AP.CCD

Abstract

Gait disorders, such as asymmetries in spatiotemporal parameters, are considered one of the leading causes of disability in individuals with Parkinson's disease (PD). Initially, gait asymmetry can be attributed to unilateral motor degeneration, and its progression is associated with changes in motor cortex activity. Individuals with PD exhibit increased motor cortex activity as a compensatory strategy to cope with motor deficits and maintain gait control. In this context, therapies that directly modulate cortical activity, such as transcranial direct current stimulation (tDCS), may contribute to reducing gait asymmetry. This study aims to investigate, through two randomized clinical trials, the effects of single and multiple tDCS sessions on gait asymmetry in individuals with PD. In the first study, the effects of three tDCS protocols, applied for 20 minutes at an intensity of 2 mA, will be compared: (1) unilaterally over the motor cortex contralateral to the most affected side, (2) unilaterally over the motor cortex ipsilateral to the most affected side, and (3) bilaterally over the motor cortex. The protocol order will be randomized for each participant, with a one-week interval between sessions. In the second study, the effects of multiple tDCS sessions on gait asymmetry will be evaluated, using the most promising protocol identified in Study 1. The intervention will last four weeks, with 20-minute sessions at 2 mA conducted on non-consecutive days (48-hour intervals). The findings from these studies will provide a solid theoretical foundation for understanding the effects of a non-pharmacological therapy on gait asymmetry in individuals with PD, contributing to the development of more effective clinical strategies. (AU)