A Randomized Trial of Hyperbaric Oxygen in U.S. Service Members with Post-Concussive Symptoms
In prior Department of Defense studies participants with persistent post-concussive symptoms after mild traumatic brain injury exposed to hyperbaric oxygen (HBO2) or sham chamber sessions reported improvement regardless of allocation.
In this exploratory, double-blind, sham-controlled trial of HBO2 for military personnel with persistent post-concussive symptoms, 71 randomized participants received 40 60-minute HBO2 (1.5 atmospheres absolute, N=36) or sham chamber sessions (air, 1.2 atmospheres absolute, N=35). At baseline, 35 participants (49%) met post-traumatic stress disorder (PTSD) criteria. Outcomes included post-concussive symptoms, quality of life, neuropsychological, neurological, electroencephalography, sleep, audiology/vestibular, autonomic, visual, neuroimaging, and laboratory testing, at baseline, 13 weeks (shortly post-intervention), and six months, plus 12-month symptom questionnaires.
By the Neurobehavioral Symptom Inventory, the HBO2 group had improved 13-week scores compared to sham (HBO2 mean change -3.6 points, sham mean change +3.9 points, P=0.03). In participants with PTSD, change with HBO2 was more pronounced (-8.6 points vs. +4.8 points with sham, P=0.02). Rivermead Post-Concussion Symptom Questionnaire RPQ-3 improved with HBO2 compared to sham (mean change difference -1.5, P=0.01). The PTSD Checklist-Civilian version scores also improved in the HBO2 group, and more so in the subgroup with PTSD. Improvements regressed at six and 12 months. HBO2 improved some cognitive processing speed and sleep measures. Participants with PTSD receiving HBO2 had improved sensory organization test scores and reduced vestibular complaints at 13 weeks. Participants without PTSD had improved anger control with HBO2. Most measures independent of patient reports did not change over time or did not change in a way that consistently favored one intervention over another.
By 13 weeks, HBO2 improved post-concussive and PTSD symptoms, cognitive processing speed, sleep quality, and vestibular symptoms, most dramatically in those with PTSD. However, most changes did not persist to six to 12 months. For military personnel, additional HBO2 studies are warranted.