To assess the sensitivity of traditional neuropsychological tests and of a behavioral inventory of executive disorders in a large sample of patients with chronic severe traumatic brain injury.
A total of 112 patients were compared with 780 healthy controls from a larger database. The GREFEX battery included 7 widely used tests and the Behavioral Dysexecutive Syndrome Inventory (proxy rating). A previously described statistical methodology was used, controlling for age, education, and gender. Summary scores were computed and performance was dichotomized on the basis of 5th percentile cutoffs from controls' z scores.
The frequency of cognitive impairment was high (55.4%) but lower than that of behavioral changes (81.5%). Double dissociations were observed between cognitive and behavioral assessments. Behavioral changes exhibited larger effect-sizes as compared with cognitive impairments. Logistic regression analysis showed that 3 cognitive tests (verbal fluency, Stroop reading, and Trail Making Test-B) and 3 behavior z scores (hypoactivity, anticipation, and hyperactivity) best discriminated patients from controls.
Behavioral changes were more frequent and severe than cognitive deficits, at least as assessed with traditional testing. The present results also suggest that a shortened battery may provide a rapid screening method with reasonable sensitivity to detect deficits of executive functions in patients with severe traumatic brain injury.