Acute Intermittent Hypoxia to Improve Airway Protection in Chronic Traumatic Brain Injury

Inclusion Criteria: * Adults aged 21-80 years * A mild to moderate traumatic brain injury (TBI) confirmed by medical records * A Glasgow Coma Scale score between 9-15 * Able to consent independently * Women of child-bearing age must be comfortable confirming a negative pregnancy prior to participating in the study Exclusion Criteria: * Other neurological diagnoses or a diagnosis of a severe psychiatric disorder * Severe aphasia preventing a participant from understanding the protocol and consent form * Pre-existing hypoxic pulmonary disease * History of obstructive lung diseases such as chronic obstructive pulmonary disease (COPD) or significant asthma) * Severe hypertension (\>160/100) * History of head and neck cancer * Allergy to barium sulfate * Ischemic cardiac disease