A Virtual Reality System for Delivery of Military-specific Vestibular Rehabilitation After Mild Traumatic Brain Injury: The Praxis Study Protocol

Abdulmohsen M. Alroumi^1*Carrie W. Hoppes^1,2*Susan L Whitney¹Zhihao Li³Lisa Holt³Sridhar Ramakrishnan³Shannon L Barnicott⁴Meghan T Logeais⁴Holly Richard³Shane R. Salter³Jeffrey M Tiede⁴Michael D. Wirt⁵Pedram Hovareshti³

• ¹University of Pittsburgh, Pittsburgh, Pennsylvania, United States
• ²Advanced Exposures, Diagnostics, Interventions, and Biosecurity (AEGIS) Program, Joint Base San Antonio-Lackland Air Force Base, TX, United States
• ³BlueHalo, Rockville, MD, United States
• ⁴Department of Rehabilitation Medicine, Brooke Army Medical Center, San Antonio, Texas, United States
• ⁵Department of Radiology, Brooke Army Medical Center, San Antonio, Texas, United States

Mild traumatic brain injury (mTBI) is a prevalent issue among military service members, often resulting in persistent vestibular dysfunction that can impair operational performance. Vestibular, sensory, and cognitive deficits following mTBI hinder critical warrior tasks such as moving under fire and maintaining situational awareness. Despite advances in rehabilitation, there remains a need for interventions that replicate the complex demands of military environments. This study introduces Praxis, a novel virtual reality (VR) system designed to deliver multisensory vestibular rehabilitation to service members with persistent post-mTBI symptoms. Praxis integrates low-cost wearable sensors and VR environments to enhance gaze stability, balance, and cognitive-motor integration through military-relevant tasks. The primary goals of this pilot study are twofold: 1) to evaluate the feasibility of using the Praxis system to deliver VR, military-specific multisensory rehabilitation to a representative sample of 15 service members with vestibular-related complaints post-mTBI over a four-week period, and 2) to evaluate objective measures, including advanced neuroimaging, to support return-to-duty (RTD) decisions by correlating functional performance improvements with neurophysiological changes. Patients will complete multisensory exercises using Praxis in conjunction with standard rehabilitation provided by the Special Operations Performance and Recovery (SPaR) Program at the Center for the Intrepid. A control group without vestibular-related complaints post-mTBI will receive the standard SPaR Program treatments. Outcome measures include Praxis scores, selfreported questionnaires, functional performance on military-specific tasks, self-reported symptom severity, and neurophysiological changes assessed through resting-state functional magnetic resonance imaging (rs-fMRI). Usability will be evaluated using the System Usability Scale (SUS), with success defined by a SUS score of 68 or higher. Secondary objectives explore the correlation between performance improvements, neurophysiological changes, and rehabilitation compliance. By capturing objective data through wearable sensors and advanced neuroimaging, this study aims to bridge the gap between clinical assessments and real-world functional performance. The findings will inform future large-scale trials and provide critical insights into the role of VR and multisensory rehabilitation in post-mTBI recovery, supporting improved RTD decisions and enhancing warfighter readiness. This protocol contributes to the advancement of neurorehabilitation by integrating technology-driven solutions tailored for military populations.