The Effects of Fatigue and the Post-Concussion Syndrome on Executive Functioning in Traumatic Brain Injury and Healthy Comparisons

ABSTRACT

In this study; behavioural manifestations of compromised executive control; including perseveration and reduced inductive reasoning; on the Wisconsin Card Sorting Test (WCST) were investigated. Performance was affected by fatigue in both a head-injured and matched population; which has implications for health care professionals involved in rehabilitation and assessment. A fatigue condition was manipulated for 15 moderate to severe traumatic brain injury (TBI) individuals through the course of a three-hour neuropsychological testing session. A comparison sample of 15 participants in a group of 'no history of TBI' was fatigued through the same approach. All fatigued participants (with and without TBI) displayed trends towards increased levels of perseveration and reduced inductive reasoning on the WCST. Thus; the effects of fatigue on high-level functioning are pervasive even when not head-injured. This finding supports the sub-optimal performance in cognitive skills; specifically in executive control; that is often found in fatigued people. These findings are relevant for the manner in which rehabilitation interventions and medico-legal assessments are structured. Importantly; the order of tests; their interpretation and rest sessions should be clearly indicated and interpreted in assessment reports and rehabilitation sessions