Patients presenting to Emergency Departments that are a part of the AHCC (Academic Health Center Consortium) and/or ERNES (Emergency Research Network of the Empire State) networks.

Inclusion Criteria:

• Patients presenting with head trauma to any of the AHCC/ERNES EDs, meeting the following criteria will be eligible to participate:

  • Presence of mild TBI per study definition
  • Arrival at the ED within 4 hours of injury
  • ED workup includes a Head CT

(Controls are eligible if they present to the Outpatient Lab for routine bloodwork during enrollment hours)

Exclusion Criteria:

• Time of injury not able to be determined
• Head CT not done as part of clinical emergency care
• Incarcerated
• Non-English or Spanish speakers
• Absence of parent/guardian for minor subjects
• Subject and/or parent/guardian do not have capacity to consent
• Head injury due to birth trauma, anoxia, inflammatory, toxic, infectious or metabolic encephalopathies that are not complications of head trauma
• Ischemic or hemorrhagic stroke without associated trauma

(Controls are excluded if they have any of the following:History of brain tumor, melanoma and/or Alzheimer's disease; History of concussion, bone fracture or stroke (CVA or TIA) in the past month; History of surgery in the past month; Inability to obtain consent from subject and/or parent due to lack of capacity or absence of parent/guardian of minor; Inability to speak or read English; Incarceration)