Hyperbaric Oxygen Treatment for Veterans With Traumatic Brain Injury

Participants who consent to the study will undergo a comprehensive baseline assessment in two sessions. Baseline A. This visit will involve questions about the participant's brain injury and relevant medical history, and surveys to learn about symptoms related to the participant's mood, sleep, pain, behaviors (e.g. drug and alcohol use), and life satisfaction. Some surveys may be administered via an interview or as an electronic survey. After Baseline A assessments are completed, the investigators will determine if the participant meets the initial criteria to continue participation. Baseline B. During this in-person visit, the investigators will have the participant do some thinking exercises by asking him/her to remember words, make decisions about shapes, draw and remember figures, and other similar tasks. The participant will also be asked questions about stress-related symptoms. The investigators will also draw up to 65-mL of blood from the participant's arm to detect inflammation and a brief physical exam (e.g. vision test, breathing functioning, heart rate). The participant will have a chance to complete optional procedure (described below). After Baseline B, the investigators will determine if the participant is eligible to continue their participation. If the participant is eligible, the next stage is "Randomization" to treatment. If the participant is not eligible, study participation will be over. Randomization: The participant will be randomized to either HBOT (chamber pressurized to 2 ATA with 100% oxygen) or to a placebo condition (chamber that remains unpressurized and has 21% oxygen). The participant will not get to choose the treatment. The participant nor the PI will know which treatment is received. HBOT or Placebo Dives: Both conditions will take place in a chamber, and each treatment session is called a "dive". The participant will then complete 40 HBOT or placebo dives in 12 weeks at USF. Every dive, the investigators will record the participant's blood pressure, respiration (breathing) rate, and pulse. If the participant is diabetic, the investigators will also record their glucose levels. Then the participant will change into a medical gown and lay down in a clear chamber for their dive. The participant will be in the chamber for about 76 minutes (60 min treatment). Every 5 dives, the participant will complete self-report measures about how they are currently feeling and a barotrauma screening. Every 10 dives, participants will undergo another a brief physical exam, similar to Baseline B. While the FDA has approved HBOT for some conditions, it is considered an experimental therapy for TBI. The entire visit should last about 90 minutes from self-report measures to getting dressed. The participant's regular medical treatment will not change if they take part in the research. Mid-treatment Assessments: After the 20th dive is complete, the investigators will ask the participant to complete a mid-treatment assessment visit. The investigators do this to monitor how the participant are feeling and thinking. During this visit the participant will complete many of the same self-report measures and interviews as they did during the baseline visits. The participant will also give up to 65-mL of blood at this mid-treatment visit. Posttreatment Assessments: After the 40 dives are complete, the investigators will ask the participant to complete 1 post-treatment visit at approximately 2 weeks after the last dive. The investigators do this to continue monitoring how the participant is feeling and thinking. During this assessment the participant will complete many of the same self-report measures and interviews as he/she did during the baseline visits and the mid-treatment visit. In addition, the participant will answer a question about global impression of change. They will also be asked to which group they believe they were assigned to: Treatment or Sham. The participant will also give up to 65-mL of blood. After the participant completes the Posttreatments assessments, the investigators will tell him/her which treatment he/she was randomized to receive. If the participant was randomized to the Placebo treatment, he/she will be given the opportunity to receive the actual treatment.