Study I (CHI that occurred at least 3 years ago): Patients undergo standardized and computer based testing of cognition, attention, planning ability, organizational ability, memory, fine motor functioning, reading and math skills, language, and behavioral and emotional functioning on day 1. Patients then undergo brain magnetic resonance imaging (MRI) on the same day. While each patient undergoes testing, the patient's parent/guardian answers interview questions regarding the patient's functional and emotional status since the injury, and the family's functional status, exposure to stressful events, and psychiatric history. Prior to the visit, a questionnaire regarding classroom behaviors, such as ability to focus in school and perform class work, is mailed to each patient's teacher.