The purpose of the study is to determine if a specific blood protein, S-100B, can help predict who will have a traumatic abnormality on head CT scan after a concussion. We will compare the levels of this protein in the subject's blood to the initial head CT scan and to how the subject is feeling one month after injury. We hope that the information we collect in this trial will help us determine who needs a head CT scan after a concussion and who may be more likely to have trouble recovering from a concussion.

The primary objective of this study is to determine the ability of a serum S-100B to predict traumatic abnormalities on brain CT scan after mild traumatic brain injury (mild TBI). The secondary objective is to determine the relationship between initial S-100B levels and cognitive outcome at one month.

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)

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.