Cognitive sequelae and recovery course after moderate and severe head injury

The quality of survival after severe and moderate head injury is highly dependent on the adequacy of cognitive recovery. The intellectual sequelae of head injury impede social and occupational reintegration more than physical disabilities do. The present study examines the course of cognitive recovery from the time of admission to 1 year after trauma. Included in the study were 68 patients with severe or moderate head injury who were 15 to 55 years old. The severity of injury was determined by the Glasgow coma scale. For this analysis, the data from tests of general intellect, language, verbal and nonverbal memory, and fine motor coordination were utilized. Standard scores (Z scores) were calculated for each test using the available normative data. Evaluation at discharge or 3 months after injury revealed I.Q. scores about 1.5 standard deviations (SD) below the mean, whereas language functioning was 4 SD, verbal memory was 5 SD, nonverbal memory was 5 SD, and fine motor coordination was 3 to 5 SD below the mean. All cognitive functions showed improvement over a 1-year period. Most of the recovery in linguistic functioning occurred during the first 6 months after trauma. This study suggests that all patients sustain significant mental sequelae after severe or moderate head injury. In spite of significant improvement during the 1st year, patients continue to have marked impairment in cognitive functions.