SIR–We read with interest the review by Stores and Stores, outlining concerns about sleep problems after paediatric traumatic brain injury (TBI) and the lack of clinical and research attention this topic has received. We strongly agree that the literature from adult TBI research and preliminary studies in paediatric TBI populations indicates the importance of increasing the evidence base in this area.
The paediatric research literature is indeed limited, and Stores and Stores review a number of papers, mostly in mild TBI samples via parent-proxy report of sleep problems. Only two studies in Stores and Stores' review examined sleep after mild TBI using objective measurement tools (actigraphy or polysomnography). Kaufman et al. found poorer sleep efficiency and more night-wake-time on polysomnography and 5-night actigraphy in mild paediatric TBI compared with healthy controls. However, the design of this study meant that the sleep difficulties identified in the index group could not be attributed to brain injury.
Milroy et al. compared mild TBI with orthopaedic injury controls on standardized sleep report (self and proxy) measures and with 5-night actigraphy. Contrary to Stores and Stores' summary of the study, no differences were found on actigraphy parameters for sleep efficiency, total-wake-time for measures of night-to-night variability or in the proportion defined with sleep problems by parent-report. Taken together with group comparison studies of post-concussional symptoms, the current evidence suggests that sleep difficulties do not occur more often following mild paediatric TBI when compared with injury controls; but that mild TBI and injury control groups may both have elevated rates of sleep problems. At present, there is no evidence to support a view that sleep difficulties are specifically associated with mild TBI.
More severe TBI can be associated with greater sleep disruption, but evidence here is extremely limited. Parent-report studies, as reviewed by Stores and Stores, indicate increased parent-report of sleep difficulties after moderate–severe TBI. Recently, Sumpter et al. found that moderate–severe paediatric TBI was associated with significantly more parent and self-report of sleep problems and actigraphy-measured sleep inefficiency in the form of sleep onset and maintenance problems in comparison with siblings (a control for psychosocial, family, and demographic factors). Future research adopting objective measures of sleep quality and quantity after moderate–severe TBI is warranted to better understand relationships between emotional, cognitive, and behavioural symptoms and sleep problems) in a group already at risk of poor psychosocial adjustment.