Eligibility Criteria- INCLUSION CRITERIA:
1. Age 18 to 40
2. Able to give consent
3. Normal clinical examination for healthy subjects
4. Must be able to follow instructions and perform required tasks, and TBI patients must have the Mini-mental state examination (MMSE) score of 25 or above.
5. Clearly right dominant handedness as assessed by Handedness scales
Traumatically induced physiological disruption of brain function, as manifested by at least on the following:
1. Any loss of consciousness
2. Any loss of memory for events immediately before or after the accident (except for short-lasting benzodiazepines for sleep.
3. Focal neurological deficit(s) that may or may not be transient
4. Any alteration in metal state at the time of the accident (e.g. feeling dazed, disoriented or confused) and focal neurological deficit (s) that may or may not be transient, but where the severity of the injury does not exceed the following:
- Loss of consciousness (LOC) of approximately 30 min
- After 30 min, an initial Glasgow Coma Scale (GCS) sore of 13 - 15 (or clinically diagnosed concussion) and
- Post-traumatic amnesia (PTA) not greater than 24 hour
Those meeting the same criteria as mild TBI plus any one of the following:
1. GCS of 9-12 (if available) or results of a clinical evaluation as moderate TBI
2. Mental status change or LOC 30 min to 24 hour
3. PTA 1-7 days
1. Being diagnosed as an alcoholic or with drug addiction.
2. Chronic use of medications acting primarily on the central nervous system such as those for seizures (e.g., carbamazepine, phenytoin) except for short-lasting benzodiazepines for sleep and antidepressants (e.g., SSRIs and SNRIs).
4. Medical or technical contraindications to MRI procedures or devices producing artifacts that impair MRI signal (e.g., dental braces, pacemakers, implanted medication pumps, cochlear devices, neural stimulators, certain metals in the cranium, surgical clips, and other metal/magnetic implants, claustrophobia)
5. History of epilepsy (to avoid brain abnormalities other than mild to moderate TBI)
6. Less than three months post-TBI and with severe post traumatic stress disorder (PTSD) or PTSD Check List (PCL) score > 60
7. Penetrating head wound
8. For healthy volunteer, history of brain injury and/or structural MRI abnormality.
9. Staff from our section