tPBM in Older Adults With Traumatic Brain Injury

Inclusion criteria

• Able to give written informed consent and follow study procedures.
• Age ≥ 55 years and ≤ 85 years.
• History of non-penetrating TBI of at least moderate severity,

• defined by Emergency Department Glasgow Coma Scale (GCS) < 13,
• or post-traumatic amnesia > 24 hours,
• or loss of consciousness > 30 minutes,
• or evidence of trauma-related abnormality on acute neuroimaging.
• Between 1 and 2 years post injury.

Exclusion criteria

• Delayed loss of consciousness due to expanding lesions
• Diagnosis of dementia, history of brain tumor, or other serious neurological disorder
• Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 diagnosis of alcohol or drug use disorder or history of other major psychiatric illness diagnosed with Mini-International Neuropsychiatric Interview (MINI)
• History of significant cardiovascular or cerebrovascular pathology before sustaining TBI
• Unstable medical conditions or medications impacting cognition (e.g., topiramate)
• Significant skin conditions on the subject's scalp in the area of illumination
• Large bilateral prefrontal cortex (PFC) lesions (i.e., more than 50% of our middle frontal gyrus region of interest (ROI) in both hemispheres)
• Claustrophobia or metallic foreign bodies that would preclude MRI
• Unwilling/unable to comply with study as judged by the Principal Investigator
• Body mass index > 40 kg/m2 to fit comfortably in MRI
• Past intolerance or hypersensitivity to tPBM
• Any use of light-activated drugs (photodynamic therapy) within 14 days prior to study enrollment