Cognitive impairment after head injury.

Cognitive impairment is common after head injury, even when the injury has been minor and does not require inpatient assessment or management. The intellectual deficit is maximal in the first week after injury and tends to resolve spontaneously within three or four weeks. It may, however, still be present six months or longer after the injury. Neuropsychologic testing is required to detect subtle cognitive deficits that may nevertheless have far-reaching effects. Cognitive impairment after head injury has specific implications for family physicians, team physicians, educators and athletic coaches.