Why Use Immersive Virtual Reality to Assess Gait in Functional Motor Disorders?

Area of Science:

• Neuroscience
• Gait Analysis
• Virtual Reality Technology

Background:

• Functional motor disorders (FMD) are disabling conditions influenced by attention.
• Immersive virtual reality (iVR) engages attentional and sensory networks.
• iVR's application in FMD is currently limited.

Purpose of the Study:

• To investigate if iVR differentially affects gait in people with FMD (PwFMD) compared to people with Parkinson's disease (PwPD) and healthy controls (HC).
• To analyze spatiotemporal gait parameters under varying cognitive and sensory loads in real-world and iVR environments.
• To understand the impact of cognitive load on gait through dual-task effects.

Main Methods:

• Spatiotemporal gait parameters were tracked using wearable insoles in PwFMD (n=30), PwPD (n=32), and HCs (n=42).
• Participants walked in three real-world and three iVR conditions with increasing cognitive/sensory load.
• Receiver operating characteristic (ROC) analysis and repeated-measures ANOVA were used to evaluate group and condition effects.

Main Results:

• iVR gait parameters (speed, stride length, swing-time variability) distinguished PwFMD and PwPD from HCs, especially under dual-task load.
• No gait parameter reliably differentiated PwFMD from PwPD using ROC analysis.
• Significant group × condition interactions were found for gait parameters; dual-task cost was higher in PwPD than PwFMD.

Conclusions:

• iVR highlights context-dependent gait abnormalities in PwFMD and PwPD.
• Differential responses to cognitive load were observed between PwFMD and PwPD.
• iVR serves as a valuable paradigm for probing the underlying mechanisms of gait disorders.