This study (Part 3) is designed to build a database including EEG, neurocognitive performance, clinical symptoms, history and other relevant data, which will be used to derive a multimodal EEG based algorithm for the identification of concussion and tracking of recovery.

Injured/concussed subjects will be studied at time of injury, and at 3 follow-up time points following injury. Subjects will come from the sports and other populations of concussed individuals. They will be matched with controls i.e. not head injured subjects who will also undergo the same set of tests and the same time intervals as the injured subjects. An additional pool of uninjured (not head injured) subjects will be collected who will be assessed at a single time point. This data will be used to populate a database for the purpose of deriving a multimodal concussion index.

Inclusion Criteria:

For Injured subjects:

1. Having sustained a traumatic closed head injury within 72 hours (3 days) from time of injury at time of BrainScope assessment;
2. GCS 13-15 at time of BrainScope assessment;
3. No hospital admission due to either head injury or collateral injuries for >24 hours.

For Matched Controls:

1. GCS 15 at time of BrainScope assessment;
2. No prior history of concussion or TBI in the last year.

Exclusion Criteria:

1. Previously enrolled in the BrainScope CAS Studies;
2. Current CNS active prescription medications taken daily, with the exception of medications being taken for the treatment of Attention Deficit Disorder (ADD) or Attention Deficit Hyperactivity Disorder (ADHD);
3. Forehead, scalp or skull abnormalities that prevents headset application or EEG data collection;
4. History of brain surgery or neurological disease;
5. Pregnant women;
6. Subjects who do not speak English (non-English speaking parents are allowed to consent so long as translation of the consent form in their native language is available);
7. Acute intoxication;
8. Evidence of illicit drug usage;

For Injured subjects:

1. Loss of consciousness ≥ 20 minutes related to the concussion injury;
2. Active fever defined as greater than 100ºF or 37.78ºC at time of BrainScope assessment;
3. Evidence of abnormality visible on Computerized Tomography (CT) of the head related to the traumatic event (Note: neuroimaging is not required for enrollment).

For Matched Controls:

1. Any focal neurological signs including aphasia, apraxia, diplopia, facial droop, dysarthria/slurred speech;
2. History of Motor Vehicle Accident (MVA) requiring an Emergency Department visit within the past 1 year.

Approximately 490 Injured, Matched Control and Healthy Volunteer subjects will be recruited from high schools, college universities, concussion clinics and emergency rooms.