Introduction

Parkinson’s Disease is a progressive neurological disorder resulting from the death of dopamine-producing cells in the substantia nigra. People with Parkinson’s disease require effective rehabilitation therapies to control the motor symptoms that are commonly associated with this disease. Transcranial current direct stimulation is a promising tool to enhance sensorimotor functioning in people with Parkinson’s disease, and the combination of transcranial current direct stimulation with Virtual Reality tasks is being explored in motor functioning, however, there is still a lack of evidence.

Objective

compare the motor performance between an active or sham single session of transcranial direct current stimulation combined with a Virtual Reality task in individuals with Parkinson Disease.

Methods

a triple-blinded randomized controlled trial protocol was performed. Fifty-four individuals with a Modified Hoehn & Yahr Scale rating from 1 to 4 were recruited. Individuals were randomly assigned to the following groups: active Transcranial Direct Current Stimulation (Transcranial Direct Current Stimulation + Virtual Reality task) or (sham Transcranial Direct Current Stimulation + Virtual Reality task). The protocol was performed in 18 minutes consisting of the following blocks: (5 minutes of initial rest stimuli, 4 minutes of the Transcranial Direct Current Stimulation + Virtual Reality task for Upper Limbs, 4 minutes of the Transcranial Direct Current Stimulation + Virtual Reality task for Lower Limbs, and 5 minutes of final rest stimuli). The active Transcranial Direct Current Stimulation protocol included low-frequency Transcranial Direct Current Stimulation with an intensity of 2 milliamperes (mA) over the primary cortex (M1) area of the dominant side of the brain.

Results

a significant effect for Groups and Blocks was found considering the measures of absolute and variable errors. Both active and sham Transcranial Direct Current Stimulation groups showed improvement in Upper Limb performance compared to Lower Limb performance.

Conclusion

active Transcranial Direct Current Stimulation could be an effective tool for enhancing motor performance during a Virtual Reality task. This may involve improved accuracy and precision of movement in both the Upper and Lower Limbs of individuals with Parkinson Disease. Positive effects in the active Transcranial Direct Current Stimulation were noticeable, even with a single session of Transcranial Direct Current Stimulation. In future research, investigation of the effect of a longer-term protocol is recommended, including follow-up measures.