# Stochastic resonance stimulation effect on stability during walking in people with Parkinson disease

## TL;DR

This study explores how stochastic resonance stimulation affects walking stability in people with Parkinson disease during visually perturbed walking.

## Contribution

The study investigates the effect of individualized stochastic resonance stimulation on gait stability in Parkinson disease patients.

## Key findings

- Stochastic resonance increased center of mass excursion, indicating reduced stability on the more affected side.
- Balance control mechanisms showed no significant changes with stochastic resonance stimulation.
- Participants exhibited more sway without altering balance strategies under stochastic resonance.

## Abstract

People with Parkinson disease (PwPD) often face challenges with maintaining balance while walking, which can stem from sensory dysfunction. Studies have identified different biomechanical strategies that aid in preserving upright balance control. Stochastic resonance (SR) stimulation delivers sub-threshold electrical noise to enhance the detection capabilities of dysfunctional sensory systems. Yet, the effectiveness of SR in enhancing gait stability in PwPD is undetermined. The purpose of this study was to investigate the effects of SR on balance control during visually perturbed walking in PwPD (NCT06829342).

Fourteen individuals with PD completed the study. We established individualized sensory thresholds for SR stimulation and identified the optimal SR intensity. Following this, the participants walked within a virtually perturbed environment. Center of mass (CoM) excursion, foot placement, and ankle roll responses were assessed bilaterally.

Peak CoM excursion showed a significant increase, indicating reduced stability, with the SR condition compared to no-SR at the more affected side. Outcome measures related to balance control mechanisms were insignificant.

With SR, PwPD were driven by the induced fall with more sway and without significant alterations in balance strategies, which might be due to adding more noise to sensory processing and misidentifying the more affected side.