Executive Dysfunction following Traumatic Brain Injury and Factors Related to Impairment

Deficits in executive function are commonly reported following Traumatic Brain Injury (TBI) and are important for establishing functional impairments. Understanding the nature of executive dysfunction following TBI is often complicated by secondary factors that can impact measured ability. This study sought to clarify the persistent effects of TBI on executive function, as measured by the Wisconsin Card Sorting Test (WCST), while accounting for effort given during testing, as measured by the Portland Digit Recognition Test. Results suggested a dose-response relationship between TBI severity and subsequent WCST deficits. Mild TBI patients who provided good effort during testing showed no observable differences from locally matched controls on WCST performance. Effort during testing was found to have a larger overall effect on WCST performance than moderate-to-severe TBI or dementia. The present study highlights the need to account for secondary factors, such as effort during testing, to accurately measure cognitive dysfunction following compensable injuries.