Hyperbaric oxygen for post-concussive symptoms in United States military service members: a randomized clinical trial
Authors:   Division of Hyperbaric Medicine Intermountain Medical Center, Murray, Utah, and Intermountain LDS Hospital, Salt Lake City, Utah, Weaver Lindell K. ,   University of Utah School of Medicine, Salt Lake City, Utah, Wilson Steffanie H. ,   The Emmes Corporation, Rockville, Maryland, Lindblad Anne S. ,   The Emmes Corporation, Rockville, Maryland, Churchill Susan ,   Division of Hyperbaric Medicine Intermountain Medical Center, Murray, Utah, and Intermountain LDS Hospital, Salt Lake City, Utah, Deru Kayla ,   Division of Hyperbaric Medicine Intermountain Medical Center, Murray, Utah, and Intermountain LDS Hospital, Salt Lake City, Utah, Price Robert C. ,   Evans Army Community Hospital, Fort Carson, Colorado, Williams Chris S. ,   Lovelace Biomedical Research, Albuquerque, New Mexico, Orrison William W. ,   Lovelace Biomedical Research, Albuquerque, New Mexico, Walker James M. ,   Lovelace Biomedical Research, Albuquerque, New Mexico, Meehan Anna ,   Lovelace Biomedical Research, Albuquerque, New Mexico, Mirow Susan ,   University of Utah School of Medicine, Salt Lake City, Utah,   Lovelace Biomedical Research, Albuquerque, New Mexico, Team BIMA study 
Published: May 2018

Background: In prior military randomized trials, participants with persistent symptoms after mild traumatic brain injury (TBI) reported improvement regardless of receiving hyperbaric oxygen (HBO2) or sham intervention. This study’s objectives were to identify outcomes for future efficacy trials and describe changes by intervention. Methods: This Phase II, randomized, double-blind, sham- controlled trial enrolled military personnel with mild TBI and persistent post-concussive symptoms. Participants were ran- domized to receive 40 HBO2 (1.5 atmospheres absolute (ATA), >99% oxygen, 60 minutes) or sham chamber sessions (1.2 ATA, room air, 60 minutes) over 12 weeks. Participants and evalua- tors were blinded to allocation. Outcomes assessed at baseline, 13 weeks and six months included symptoms, quality of life, neuropsychological, neurological, electroencephalography, sleep, auditory, vestibular, autonomic, visual, neuroimaging, and laboratory testing. Participants completed 12-month questionnaires. Intention-to-treat results are reported. Results: From 9/11/2012 to 5/19/2014, 71 randomized parti- cipants received HBO2 (n=36) or sham (n=35). At baseline, 35 participants (49%) met post-traumatic stress disorder (PTSD) criteria. By the Neurobehavioral Symptom Inventory, the HBO2 group had improved 13-week scores (mean change -3.6 points, P=0.03) compared to sham (+3.9 points). In participants with PTSD, change with HBO2 was more pronounced (-8.6 vs. +4.8 points with sham, P=0.02). PTSD symptoms also improved in the HBO2 group, and more so in the subgroup with PTSD. Improvements regressed at six and 12 months. Hyperbaric oxygen improved some cognitive processing speed and sleep measures. Participants with PTSD receiving HBO2 had improved functional balance and reduced vestibular complaints at 13 weeks. Conclusions: By 13 weeks, HBO2 improved post-concussive and PTSD symptoms, cognitive processing speed, sleep quality, and balance function, most dramatically in those with PTSD. Changes did not persist beyond six months. Several outcomes appeared sensitive to change; additional studies are warranted.