Rapidly evolving virtual reality (VR) and augmented reality (AR) technologies are being incorporated by many large-scale industries, and the medical field is no exception. One area that has gained significant attention in recent years is virtual rehabilitation which allows physical therapists to leverage state-of-the-art immersive virtual environments to uniquely address functional deficits in patients who are unresponsive to conventional treatment techniques. Advanced VR and AR technologies are now available in commercially available small-scale, mobile head-mounted displays which can be readily used in outpatient clinic settings and possibly at home.

The aim of this study is to determine whether advanced VR- and AR-based physical therapy improves functional status and reduces self-reported symptoms in individuals experiencing vestibular disorders secondary to mild traumatic brain injury (mTBI). Study participants will be randomized into treatment groups: 1) conventional therapy, 2) therapy performed using a large-scale VR system (the Computer Assisted Rehabilitation Environment or CAREN), 3) therapy performed using a mobile AR. Upon completion of treatment, groups will be compared to determine functional outcome improvements with respect to static and dynamic balance as well as reduction of vestibular symptoms.

This protocol represents Phase 2 of a project that seeks to implement mobile AR-based technologies into vestibular physical therapy. The Phase 1 protocol (EIRB Number - NHRC.2019.0002) is ongoing and will compare outcomes from the AR-based HMD system (e.g., Magic Leap One) to the VR-based CAREN system. With validated instruments from Phase 1, this pilot prospective, three-armed randomized, interventional clinical trial seeks to incorporate advanced VR- and AR-based technologies as modalities in physical therapy for servicemembers (SMs) with mTBI who also experience vestibular dysfunction. The three arms are: 1) conventional vestibular physical therapy only (CPT), 2) CAREN only (CAREN), and 3) AR HMD only (AR).

Primary:

To determine whether advanced VR- and AR-based therapy, improves functional status and reduces self- reported symptoms in SMs with vestibular dysfunction and a history of mTBI.

Hypothesis: The investigators hypothesize that after completion of vestibular physical therapy, participants in the CAREN and AR groups will have better outcomes than those in the CPT group. In the CAREN and AR groups, the investigators anticipate greater improvements in static and dynamic balance, as measured by the Sensory Organization Test (SOT), Community Balance and Mobility Scale (CB&M), and Functional Gait Assessment (FGA), as well as decreased vestibular symptoms, as measured by the Dizziness Handicap Inventory (DHI) and Activity-Specific Balance Confidence Scale (ABC).

Secondary:

To determine whether participants in the advanced technology groups demonstrate similar clinical improvements following treatment.

Hypothesis: The investigators hypothesize that after completion of vestibular physical therapy, participants in the CAREN and AR groups will show similar improvements in static and dynamic balance as well as vestibular symptoms; essentially, the investigators believe the VR- and AR-based therapies will be comparable.

Tertiary:

To investigate the user experience associated with utilizing advanced technology for the treatment of vestibular dysfunction.

Hypothesis: The investigators hypothesize that participants in the AR group will have greater satisfaction than the CAREN group, as measured by higher scores on the User Satisfaction Evaluation Questionnaire (USEQ).

Exploratory:

Efforts from this study seek to gather information to justify further implementation of AR-based therapy (using HMDs) as well as the development and incorporation of additional military-relevant tasks, such as return-to-duty tasks and measures to be developed for future research efforts.

Inclusion Criteria:

• Men and women, active duty SMs between 18 and 65 years of age and enrolled in Defense Enrollment Eligibility Reporting System (DEERS)
• History of mTBI based on the Ohio State University Traumatic Brain Injury Identification (OSU TBI-ID)
• Require vestibular physical therapy as determined by a PT
• Normal or corrected vision based on the Snellen Eye Chart of at least 20/40
• Able to consistently follow verbal and written instructions and observe safety precautions
• Able to tolerate up to 60 minutes of physical therapy exercise, with breaks
• Able to ambulate with contact guard assistance or less, and to walk unassisted over ground or on a treadmill for 10 minutes at a time
• Able to tolerate wearing a full body safety harness
• Able to tolerate wearing a head mounted display weighing up to 3 pounds for up to 60 minutes

Exclusion Criteria:

• History of a moderate or severe TBI (OSU TBI-ID; or DVBIC TBI Screening Tool)
• Under care of a physician for a neurodegenerative diagnosis
• History of seizures or syncope
• Clinical determination of Benign Paroxysmal Positional Vertigo (BPPV)
• Diagnosis of any of the following visual impairments: field cuts, macular degeneration, retinal detachment, diplopia, limited peripheral or central vision, or require prism lenses
• Unable or unwilling to use contacts for corrected vision
• Require a medical device that can be affected by radio waves such as a pacemaker, defibrillator, or hearing devices (implantable or air conduction)
• Medications with significant sedating side effects that could impact safety (i.e., Phenobarbital, Ativan, etc.)
• Women who are more than 4 months pregnant may not participate in this study due to the effects advanced pregnancy can have on balance and vision. Note: Women who choose to participate will be informed up front that there are risks associated with pregnancy including decrements in postural control and falls. Additionally, changes in hormones, metabolism, fluid retention, and blood circulation during pregnancy can affect the eyes and eyesight. Women who become pregnant during the intervention should inform their PT immediately to determine if continued participation is possible.
• Concurrent participation, either clinically and/or as a part of another research study, in vestibular physical therapy and/or PTSD treatment
• Unable to consent for any reason