Hyperbaric Oxygen Therapy for Post-Concussion Syndrome

The purpose of this study is to decrease symptom burden, improve cognitive function, and improve quality of life outcomes in subjects with mild TBI and persisting post-concussion syndrome using Hyperbaric Oxygen Treatment compared to a sham intervention. Specific Aims: 1. Evaluate the efficacy of hyperbaric oxygen treatment to improve outcomes for adults with persisting post-concussion syndrome. Specifically, the investigators hypothesize that a prescribed course of hyperbaric oxygen treatments (HBOT) will improve outcomes and quality of life in adults with persisting symptoms \>3 months after injury. 1. Decrease symptom burden as measured by the Rivermead Post-Concussion Symptoms Questionnaire (RPQ). 2. Improve cognitive function as measured by the National Institutes of Health (NIH) Toolbox Cognition Battery. 3. Improve quality of life as measured by the 36-Item Short Form Survey (SF-36). 2. Assess the safety and tolerability of hyperbaric oxygen treatments and compliance with treatment in adults with persisting post-concussion syndrome.