This study is designed to collect data which will be used to associate changes in EEG, neurocognitive performance, eNPC and clinical symptoms in concussion subtypes. The study will recruit males and females, 13-50 years old, from Concussion Centers/Programs, Sports Venues and Emergency Departments (ED) across the country, over an 18-month period (Phase 2, 12 months for Algorithm Development and Norming, and Phase 3, 6 months for Validation).

Phase 1 of this project (USAMRDC W81XWH-18-C-0157) was focused on building the automated/electronic NPC capability (eNPC). This protocol is for Phase 2, in which the CI multimodal brain function biomarker will be extended (Algorithm Development) with the inclusion of an automated ocular function measurement (AOFM), to expand the capability in the characterization of concussion. The study will also expand the range of applicability of the CI to ages 13-50 years old. Phase 2 will also include norming of eNPC across the age range. Phase 3 of the project will validate the algorithms developed in Phase 2, using the same protocol.

Inclusion Criteria:

• Age ≥13 and <51 years old at time of enrollment;
• No prior history of concussion or TBI in the last 6 months.

For head injured subjects

• Having sustained a traumatic closed head injury within 120 hours (5 days from time of injury at time of BrainScope assessment);
• GCS 13-15 at time of BrainScope assessment.

For non-concussed head-injured controls

• Having sustained a traumatic closed head injury but returned to play or deemed non-concussed following sideline (on-field) evaluation within the same game and enrolled in the study within 120 hours (5 days) from said incident.
• GCS 13-15 at time of BrainScope assessment.

For matched controls and healthy volunteers

• GCS 15 at time of BrainScope assessment.

Exclusion Criteria:

• Enrolled in any previous BrainScope clinical study;
• Current CNS active prescription medications taken daily, except for medication being taken for the treatment of Attention Deficit Disorders (ADD/ADHD); medication for smoking cessation; or medications for anxiety taken PRN (as needed);
• Forehead, scalp or skull abnormalities that prevents headset application for EEG data collection in injured/matched controls;
• History of brain tumor, brain surgery or known neurological disease including, Parkinson's, MS, Alzheimer's, dementia, epilepsy;
• History of TIA or Stroke within the last year;
• Pregnant women;
• 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);
• Acute intoxication ;
• Evidence of illicit drug abuse in the last year;
• Active fever defined as greater than 100ºF or 37.78ºC at time of BrainScope assessment;
• Subjects currently receiving dialysis or have end-stage renal disease;
• Subjects requiring advanced airway management (i.e. mechanical ventilation);
• Prisoners.

For head injured subjects

• Loss of consciousness ≥ 20 minutes related to the concussion injury;
• Evidence of abnormality visible on Computerized Tomography (CT) of the head related to the traumatic event (note: neuroimaging is not required for enrollment);
• For current injury, hospital admission (other than the Observation Unit) ranging more than 24 hours due to either head injury or collateral injuries.

For non-concussed head-injured controls

• Loss of consciousness ≥ 20 minutes related to the head impact;
• Any focal neurological signs including aphasia, apraxia, diplopia, facial droop, dysarthria/slurred speech;
• Any score >3 on a 7-point Likert scale (0=none, 6=severe) for the following symptoms at the time of BrainScope assessment (compared to how the subject normally feels): headache, dizziness, balance problems, neck pain, feeling slowed down;

For matched controls and healthy volunteers

• Any focal neurological signs including aphasia, apraxia, diplopia, facial droop, dysarthria/slurred speech;
• Hospital admission (other than the Observation Unit) ranging more than 24 hours due to either head injury or collateral injuries in the past 6 months;
• Any score >3 on a 7-point Likert scale (0=none, 6=severe) for the following symptoms at the time of BrainScope assessment (compared to how the subject normally feels): headache, dizziness, balance problems, neck pain, feeling slowed down.

For healthy volunteers

• Legally blind in one or both eyes;
• History of eye surgery in the past year;
• Any known eye disorders including age-related macular degeneration (AMD), glaucoma, lazy eye, diplopia, cataracts, etc.

Male and female study subjects aged 13-50 from participating sites will be invited to enroll the study.