Memory and head injury severity.

One hundred and two consecutive head injured patients were studied at 1 and 12 months after injury. Their performances were compared with a group of uninjured friends. The results indicate that impairment in memory depends on the type of task used, time from injury to testing, and on the severity of head injury (that is, degree of impaired consciousness). Head injury severity indices are more closely related to behavioural outcome early as compared with later after injury. At 1 year, only those with deep or prolonged impaired consciousness (as represented by greater than 1 day of coma, Glasgow Coma Scale of 8 or less, and post traumatic amnesia of 2 weeks or greater) are performing significantly worse than comparison subjects.