The Influence of Cognitive Reserve on Recovery from Traumatic Brain Injury.

Objective: we sought to determine the degree to which cognitive reserve, as assessed by the Test of Premorbid Functioning in combination with demographic variables, could act as a buffer against the effect of traumatic brain injury (TBI) on cognitive test performance.

Method: retrospective analysis of a cohort of 121 persons with TBI who completed the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) within 1-12 months after injury.

Results: regression analyses indicated that cognitive reserve was a statistically significant predictor of all postinjury WAIS-IV factor index scores, after controlling for various premorbid and comorbid confounding variables. Only for Processing Speed did injury severity make an additional statistically significant contribution to the prediction model.

Conclusions: cognitive reserve has a protective effect with regard to the impact of TBI on cognitive test performance but this effect is imperfect and does not completely negate the effect of injury severity.