Virtual Reality - Gamma Sensory Stimulation for Improving Fatigue in People With Multiple Sclerosis

Gamma Sensory Stimulation (GSS) is a non-invasive audiovisual neuromodulation method that delivers synchronized 40 Hz stimulation to engage gamma-band neural oscillations. Gamma-frequency activity is implicated in cognitive processing and large-scale network coordination, which may be disrupted in people with Multiple Sclerosis (MS), particularly in those experiencing fatigue. Prior research suggests that gamma-frequency entrainment may modulate neural network activity and support functional outcomes. This single-center, double-blind, randomized, sham-controlled pilot study investigates whether 4 weeks of GSS delivered through an immersive Virtual Reality (VR) system can reduce fatigue in individuals with MS. Participants with moderate to severe fatigue will be randomized in a 1:1 ratio to receive either active GSS or sham stimulation embedded in matched VR content. The intervention consists of 16 in-lab stimulation sessions delivered over 4 weeks (4 sessions per week). Each session includes 30 minutes of active stimulation within a standardized VR experience. The primary endpoint is the change in Modified Fatigue Impact Scale (MFIS) total score from baseline to End of Treatment (Week 4). Secondary endpoints include changes from baseline to End of Treatment (Week 4) and follow-up (Week 8) in additional validated fatigue measures (Fatigue Severity Scale, Visual Analogue Scale for Mental Fatigue, PROMIS Fatigue), cognitive performance assessed by the Symbol Digit Modalities Test (SDMT), quality-of-life measures (Neuro-QoL Fatigue), and the rate of change in Daily Fatigue Severity (DFS) across the treatment period. Exploratory outcomes include MFIS subscale scores, variability in daily fatigue ratings, embedded cognitive task performance during stimulation, and treatment acceptability. Safety and tolerability will be assessed through monitoring of adverse events, session attendance, and retention. Electroencephalography (EEG) will be collected at baseline and at End of Treatment (Week 4) for exploratory characterization of neural responses to gamma-frequency stimulation. This pilot investigation aims to generate preliminary safety, feasibility, and efficacy data to inform future multisite studies evaluating VR-based GSS as a potential at-home therapeutic approach for MS-related fatigue.