Recovery of memory and learning functions following traumatic brain injury.

Twenty-four traumatically brain-injured males, of whom eight had sustained right-sided, eight left-sided, and eight bilateral or diffuse closed head injuries, took a battery of neuropsychological tests within the first six months, the second six months, the second year and the third year post injury. Performances on WAIS Digits Forward and Backward and Rey's Auditory-Verbal Learning Test were classified as within or below normal range. Comparisons were made (1) between time periods and tests and (2) between subgroups formed by severity, site of lesion, and age. The findings give an overall picture of wide performance variability with consistent improvement in immediate memory span and learning. Recovery varied with the specific nature of the tested function, task complexity, and severity of injury. Neither age, site of injury, not recency were associated with improvement.