A treadmill training program in a gamified virtual reality environment combined with transcranial direct current stimulation in Parkinson’s Disease: Preliminary results of a mixed methods randomized controlled trial

Gait impairments in Parkinson’s disease (PD) worsen under cognitive load and often persist despite medication. Combining treadmill training with gamified virtual reality environments (GVRE) and transcranial direct current stimulation (tDCS) may address both motor and cognitive contributors. This study evaluated the effects and experiences of a cognitive-motor gait training program integrating GVRE and tDCS.

In this mixed-methods RCT, 23 participants with mild-to-moderate PD were randomized to: (1) treadmill (n = 8), (2) treadmill+GVRE (n = 8), or (3) treadmill+GVRE+tDCS (n = 7). Participants completed 12 sessions over six weeks. Primary outcomes included spatiotemporal gait parameters and executive function under single- and dual-task conditions. Secondary outcomes included balance, motor severity, fear of falling and quality of life. Interviews explored perceived effects and motivational factors.

The intervention was safe and well tolerated, with high attendance (92%). No statistically or clinically meaningful changes were observed in gait speed. Balance improved across groups (MiniBESTest + 1.48 points; p = 0.0003). A timepoint-specific improvement in cadence during motor dual-task walking was observed in the treadmill+GVRE+tDCS group compared with treadmill. Interviews revealed increased walking confidence and adoption of mobility strategies in complex walking situations.

This preliminary mixed-methods RCT supports the feasibility and acceptability of combining treadmill training with GVRE and tDCS in people with mild-to-moderate PD. While the intervention did not yield clinically meaningful improvements in gait speed, exploratory outcomes offered insight into participant experiences. Reported gains in confidence, self-monitoring, and walking strategies provide useful context. Findings should be interpreted cautiously. Larger, adequately powered, sham-controlled trials are needed to determine efficacy.