Hyperbaric Oxygen for Traumatic and Non-traumatic Brain Injury

Inclusion Criteria: * Adults, age 18-70 years, both men and women * Able to speak and read English as primary language * Able and willing to provide written informed consent for study participation. * Able and willing to complete outcome assessments and provide blood and urine samples as required by the study protocol. * Able to tolerate the chamber environment and hood placement and to equalize middle ear pressure. * Past history of at least one brain injury with persistent symptoms that meets all of the following criteria: * Brain injury of non-stroke etiology that occurred at least 6 months but no more than 10 years prior to enrollment. * At least 3 of the following persistent symptoms from the injury: headaches, dizziness or balance problems, blurred vision, tiredness/fatigue or sleep problems, seizures, remembering things or solving problems, managing stress or emotional upsets, controlling temper/irritability, depression, anxiety, post-traumatic stress, or ringing in the ears. * Normal thyroid stimulating hormone and hematocrit value greater than 35% within the previous 6 months. Exclusion Criteria: * Contraindications to hyperbaric oxygen * Insulin-dependent diabetes mellitus, or diabetes mellitus that is not reasonably controlled. * Uncontrolled seizure disorder (participants must be on therapy and seizure-free for at least 6 months). * Claustrophobia precluding chamber or hood tolerance. * Implanted devices not cleared for hyperbaric pressurization. * Pregnancy or plans to become pregnant during the study participation period. Women of childbearing potential will be asked to use an acceptable form of birth control during study participation. * Lung disease, such as emphysema, chronic bronchitis, asthma that is not well-controlled, or bullous lung disease that raises the risk for pulmonary barotrauma due to air trapping. * Active malignancy, previous malignancy (except basal cell carcinoma) in the last 5 years, or any prior treatment with bleomycin (Blenoxane). Prior treatment with doxorubicin (Adriamycin) is acceptable as long follow-up echocardiography is normal. * Chronic disease such as heart or renal failure would raise the participant's risk of adverse events during hyperbaric oxygen. * Confounds to the outcome assessments * Inability to speak English as their primary language (English fluency required because many of the outcomes are only in available in English) * Instability with walking requiring more than a cane for assistance * Alcohol …