Galvanic Vestibular Stimulation Improves Subnetwork Interactions in Parkinson's Disease

Area of Science:

• Neuroscience
• Motor Control
• Neuroimaging

Background:

• Galvanic vestibular stimulation (GVS) shows complex motor effects in Parkinson's disease (PD).
• The underlying mechanisms of GVS efficacy in PD remain unclear.
• Evaluating network-level connectivity changes offers insight into GVS mechanisms.

Purpose of the Study:

• To investigate the effects of different GVS stimuli on brain subnetwork interactions.
• To compare these effects in healthy controls (HC) and individuals with PD.
• To determine how disease and stimulus type influence GVS-induced changes.

Main Methods:

• fMRI data collected at rest and during noisy, sinusoidal, and multisine GVS (below sensory threshold).
• Subnetwork interactions analyzed using nonnegative canonical correlation analysis in 15 HC and 27 PD subjects.
• Influence of disease, stimulus type, and demographics on GVS effects examined.

Main Results:

• PD subjects exhibited decreased baseline visual-cerebellar network interactions compared to HC.
• Sinusoidal and multisine GVS were more effective than noisy GVS in improving subnetwork interactions.
• Disease severity, apathy, depression, cognitive function, and age modulated GVS benefits.

Conclusions:

• Vestibular stimulation influences system-level brain activity.
• GVS can improve PD subnetwork interactions in a stimulus-dependent manner.
• Demographics and disease status significantly associate with GVS efficacy.