Hyperbaric oxygen for mild traumatic brain injury: Design and baseline summary

The Brain Injury and Mechanisms of Action of Hyperbaric Oxygen for Persistent Post-Concussive Symptoms after Mild Traumatic Brain Injury (mTBI) (BIMA) study, sponsored by the Department of Defense, is a randomized double-blind, sham-controlled clinical trial that has a longer duration of follow-up and more comprehensive assessment battery compared to recent HBO2 studies. BIMA randomized 71 participants from September 2012 to May 2014. Primary results are expected in 2017. Randomized military personnel received hyperbaric oxygen (HBO2) at 1.5 atmospheres absolute (ATA) or sham chamber sessions at 1.2 ATA, air, for 60 minutes daily for 40 sessions. Outcomes include neuropsychological, neuroimaging, neurological, vestibular, autonomic function, electroencephalography, and visual systems evaluated at baseline, immediately following intervention at 13 weeks and six months with self-report symptom and quality of life questionnaires at 12 months, 24 months and 36 months. Characteristics include: median age 33 years (range 21-53), 99% male, 82% Caucasian, 49% diagnosed post-traumatic stress disorder, 28% with most recent injury three months to one year prior to enrollment, 32% blast injuries, and 73% multiple injuries. This manuscript describes the study design, outcome assessment battery, and baseline characteristics. Independent of a therapeutic role of HBO2, results of BIMA will aid understanding of mTBI.