Can pressurized oxygen ease lingering concussion woes?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Must have been evaluated within 3 weeks of injury and given a diagnosis of concussion by a medical professional * Must be experiencing persistent symptoms 3-12 months after injury as defined as having at least symptoms that are moderate to severe (score 3-4) OR at least a total score of 10 with at least 1 symptom rated moderate to severe (3-4) on the Rivermead Post-Concussion Questionnaire (RPQ). Exclusion Criteria: Clinically significant cardiac, neurological, psychological/psychiatric, or respiratory impairment in the opinion of the investigators, including but not limited to: 1. Pulmonary: * COPD with CO2 retention; previous/current imaging showing hyperinflation/air trapping/bullous disease/blebs * Current pneumothorax or previous spontaneous pneumothorax 2. Cardiac: * Uncontrolled HTN (systolic \>180 or diastolic \>100) * Known Ejection fraction \< 35% * Pacemaker / ICD in place (not approved for chamber use) 3. Hematological/Oncological: * Current chemotherapeutic drug use, and past history of bleomycin use. * Hereditary Spherocytosis * Sickle cell anemia 4. Neurological and Psychological: * Implanted nerve stimulators * Uncontrolled seizure disorder * Drug or alcohol abuse/dependence * Current treatment for alcohol cessation with disulfiram * Claustrophobia 5. Head and Neck: * Inability to equilibrate the pressure of middle ears and sinuses * Current or previous retinal detachment * Retinal or vitreous surgery within the past 3 months 6. Miscellaneous: * Current fever or active infection * Implanted devices not on the approved list for use with HBOT * Women who are pregnant. Women with childbearing potential are required to use effective birth control if not surgically sterile or postmenopausal for \>2 years. * Undergoing vestibular or other therapy during the intervention * Planning a change in medication during the intervention 7. Relative exclusion criteria: Diagnosis of the conditions listed below will require approval of the hyperbaric medicine physician for enrollment into the study. * Asthma * Optic neuritis * Otosclerosis surgery * Thoracic surgery * Chronic sinusitis 8. Medications: Individuals with recent (within the past six months) or concurrent use of these medications must be approved by the hyperbaric medicine physician. * Antabuse - Predisposes to oxygen toxicity * Antiseizure medications - Potential participants must have levels of their seizure medications checked within a week of their initial screening visit because low levels can predispose to oxygen toxicity. Laboratory testing must be completed by their outside treating physicians to provide to the research staff for review; the study will not obtain labs for monitoring medication levels as part of the inclusion/exclusion criteria * Meclizine - Predisposes to oxygen toxicity * Bleomycin - May cause pulmonary fibrosis that can lead to air embolism or pneumothorax in the patient receiving hyperbaric oxygen treatment. * Certain ointments/creams that cannot be removed - These may be allowed if covered with cotton dressings. * Narcotics - Can lead to cessation of the hypoxic respiratory drive. * Nitroprusside - HBOT vasoconstrictive effect interacts with nitroprusside's vasodilator effect, making intensive monitoring mandatory. * Penicillin - Predisposes to oxygen toxicity * Promethazine (Phenergan) - Predisposes to oxygen toxicity. * Corticosteroids - Decreases the threshold for oxygen toxicity. * Sulfamylon - Promotes CO2 buildup causing peripheral vasodilatation. When coupled with vasoconstriction, results are worse than with using either agent alone. Use silver sulfadiazine instead for wound care.