Sleep parameters and overnight urinary melatonin production in children with persistent post-concussion symptoms

Abstract Background Sleep disturbance is common after a mild traumatic brain injury (mTBI) in children, yet its biology is poorly understood. We aimed to explore sleep-related problems (SRPs), sleep-activity patterns, and endogenous Melatonin production in children with different recovery trajectories following mTBI. We hypothesized that children with delayed recovery would have more SRPs and abnormal sleep activity patterns, which would correlate with lower overnight Melatonin production. Methods In this prospective controlled cohort study, we enrolled 83 children with persistent symptoms at 4-6 weeks, 26 children who had clinically recovered following mTBI and 25 healthy controls. SRPs were evaluated using the sleep subscale of the Post-Concussion Symptom Inventory. Sleep actigraphy was performed for 5-7 days at 37(SD 7) days post-injury. Health-related quality of life and mood disturbance was assessed using the Child Health Questionnaire and the Behavior Assessment System for Children, 2nd Edition, respectively. Endogenous melatonin production was assessed using overnight urine collection. Results The groups were similar in age (13.9 (SD 2.6) years), sex (52% female) and socioeconomic status. Regression analysis demonstrated increased SRP in the symptomatic group (9.0; 95%CIs: 7.6, 11.1) compared to the recovered mTBI group (1.6; 95%CIs: 1.0, 2.4) and healthy controls (2.0; 95%CIs: 1.2, 3.2). Actigraphy parameters and urinary Melatonin levels were not significantly different between groups. Neither SRPs nor actigraphy parameters correlated with anxiety and depression scores. Conclusions Although children with persistent post-concussion symptoms reported more SRPs, this was not related to actigraphy sleep parameters or endogenous Melatonin levels. Further research is warranted to understand the pathophysiology of post-traumatic sleep disturbance.