ACUTE EFFECT OF HD-TDCS NEUROMODULATION ON THE SUPPLEMENTARY MOTOR AREA IN THE PREFRONTAL CORTEX DURING STEP INITIATION IN IN PATIENTS WITH PARKINSON'S DISEASE AND FREEZING OF GAIT

• Grant number: 25/08351-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Daniel Boari Coelho
• Grantee: Giovanna Del Soldato Santos
• Host Institution: Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas (CECS). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil

Abstract

During step initiation, the nervous system organizes a series of anticipatory postural adjustments (APAs) to counterbalance the forces generated by voluntary movement, ensuring stability. Recent studies point to the neural circuitry involving the supplementary motor area (SMA) as a fundamental region for the modulation of APAs. It is hypothesized that reduced activity in the AMS contributes to the pathogenesis of initial hesitation in individuals with Parkinson's disease (PD) and freezing of gait. Associated with this, studies have shown an increase in the participation of prefrontal regions as compensation for the decrease in the circuitry involved with the modulation of automatic movements. Some preliminary studies suggest that transcranial direct current simulation (tDCS) may positively affect motor and cognitive symptomatology in PD. This work aims to evaluate the acute effect of tDCS on the AMS in the modulation of the cognitive areas of the prefrontal cortex and the performance of step initiation in a cognitive-motor conflict task in individuals with PD and freezing of gait. Therefore, a triple-blind crossover study will be carried out with 24 volunteers with PD with gait freezing, who will be submitted to two sessions of tDCS, one anodic (2 mA, 20 min) and the other placebo on AMS. Kinetic and kinematic analyses will be performed, synchronized with recording the hemodynamic response by functional near-infrared spectroscopy (fNIRS), pre- and post-neuromodulation, during the step initiation activity with cognitive conflict.