Executive Functions and Their Relation to Sleep Following Mild Traumatic Brain Injury in Preschoolers.

Objectives: Traumatic brain injury (TBI) sustained during childhood is known to impact children's executive functioning. However, few studies have focused specifically on executive functioning after preschool TBI. TBI has also been associated with sleep disturbances, which are known to impair executive functions in healthy children. The aim of this study was to investigate executive functions in preschoolers with mild TBI, and to determine the role of sleep in the links between TBI and executive functioning.

Methods: The sample was drawn from a longitudinal study and included 167 children, aged 18 to 60 months, divided into 2 groups: children with accidental mild TBI (n=84) and typically developing children (n=83). Children were assessed 6 months post-injury on executive function measures (inhibition and cognitive flexibility) and sleep measures (actigraphy data and parental rating of sleep problems).

Results: The two groups did not differ in their executive abilities. However, relative to controls, children with mild TBI and shorter nighttime sleep duration or increased sleep problems exhibited poorer executive functions.

Conclusions: These results support a "double hazard" effect, whereby the combination of sleep disturbances and mild TBI results in poorer executive functions. The findings highlight the importance of assessing and monitoring the quality of sleep even after mild head injuries. Poor sleep may place children at risk for increased cognitive difficulties. (JINS, 2018, 24, 769-780).