The overall hypothesis is that the long-term cognitive and behavioral sequelae of traumatic brain injury (TBI) are due to selective disruption of the long association white matter tracts of the cerebral hemispheres, with resulting functional impairment of the network of cortical regions that are interconnected by these long-range association pathways. We propose that traumatic white matter injury can be measured with diffusion tensor imaging (DTI) and that the impaired cortical activation can be detected with magnetoencephalography (MEG), and that the results of these imaging examinations will correlate with neurocognitive status and functional recovery after TBI.

Inclusion Criteria:

• 18-50 years of age
• single episode of blunt traumatic brain injury
• symptoms of persistent post-concussive syndrome present an average of 4 months to 4 years since date of injury
• fluency in English (cognitive battery not available in other languages)
• capable of self-consent

Exclusion Criteria:

• < 18 years or > 50 years of age
• pregnancy
• history of previous TBI with loss of consciousness
• alcoholism as evidenced by Audit questionnaire
• regular use of illicit drugs
• non-English fluency
• significant psychiatric history excluding mild depression or anxiety disorder any contraindication to MRI, including claustrophobia, pregnancy, any trauma or surgery which may have left ferromagnetic material in the body, ferromagnetic implants or pacemakers; and inability to lie still for 1 hour or more

Participants will be recruited through the neurosurgery clinic at San Francisco General Hospital or referred to us by colleagues.