An observational study of the association between sleep disturbance, fatigue and cognition in the post-acute period after mild traumatic brain injury in prospectively studied premorbidly healthy adults.

Abstract

The literature examining the relationship between sleep disturbance, fatigue, and cognition in premorbidly healthy civilian adults after mTBI is very limited. The current study aimed to investigate the relationships of sleep disturbance and fatigue with cognition while controlling for psychological distress and age. Using a prospective observational design, we assessed 60 premorbidly healthy individuals approximately 8 weeks after mTBI. Participants were assessed with the Pittsburgh Sleep Quality Index and the Multidimensional Fatigue Inventory as well as measures of speed of information processing, attention, memory, and executive function; depression and anxiety were also assessed. Findings revealed associations between sleep disturbance and cognition (r2 = .586, p < .001) as well as between fatigue and cognition (r2 = .390, p < .01), independent of the impact of psychological status and age. Associations were evident in the domains of processing speed, attention, and memory, but were most consistently apparent on measures of executive function. Greater sleep disturbance was most consistently associated with poorer cognitive function. Unexpectedly, higher levels of fatigue were associated with better cognitive function, which may be explained by the coping hypothesis. Given sleep interventions have been shown to improve sleep disturbance, these findings suggest that sleep intervention may also result in improved cognition after mTBI.