WAIS-III factor index score patterns after traumatic brain injury.

Profile subtypes, based on the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) factor index scores, were examined in a sample of 166 patients with traumatic brain injury (TBI) by means of a two-stage clustering procedure. Three reliable subtypes were found that were differentiated primarily by level of performance across all factor index scores, although each of them demonstrated a relative weakness on the Processing Speed index. These subtypes were then validated on the basis of demographic variables, injury parameters, and additional psychometric measures that had not been included in the clustering procedures. The results indicated that performance on the WAIS-III after TBI was affected by both injury severity and level of education. It is concluded that there is no unique "signature" profile on the WAIS-III after TBI, except that a relative strength on the Processing Speed index is uncommon with this condition.