Pediatric and adolescent concussion is a growing area of concern as 3.9% of all children in the US in 2021 have been diagnosed with a concussion sometime during childhood (Black and Zablotsky, 2021). Sleep disturbances with concussion are common, with up to 51% of pediatric and adolescent patients reporting increased sleep disturbance within 1 week following injury (Djukic et al., 2022). Both concussion and sleep disturbance in the absence of injury have been shown to lead to deficits in cognition, reaction time, perception, balance and proprioception, autonomic function, sleep-wake regulation, and mood regulation (Bauer and Jaffee, 2021; Zimmerman et al., 2024; Vandekerckhove and Wang, 2018). These deficits can broadly impact quality of life across several domains: academic, social, physical, emotional, and mental health. Particularly, sleep disturbance immediately following concussion is highly prevalent and predictive of persistent symptom burden (Bramley et al., 2017; Patricios et al., 2023), but has not been directly examined as it relates to clinical recovery in pediatric and adolescent patients.

A recent systematic review described five distinct concussion phenotypes—cognitive, ocular-motor, headache/migraine, vestibular, and anxiety/mood—with a concussion-associated condition of sleep disturbance affecting 33% of concussed individuals not specific to phenotype (Lumba-Brown et al., 2020). Few treatments exist to address this concussion-associated condition, making it crucial to advance understanding of post-injury sleep disturbances to improve clinical care. Thus, identifying the individual factors contributing to sleep disturbances after concussion is critical to informing prevention or mitigation tactics prior to injury, as well as effective treatments following injury.

While it is critical to consider individual demographic or injury factors that contribute to recovery, it is also paramount to include familial, environmental, and other external metrics that influence a patient's recovery pathway and potential. For example, recent pediatric research has identified the Child Opportunity Index (COI) as a useful composite measure of factors external to the child or family themselves that contribute to health and wellbeing. COI is a robust, nationally-normed score developed from census data as a composite measure of community-level infrastructure relating to resource availability and quality, as well as other geographic and neighborhood factors that contribute to healthy childhood development (COI 3.0 Overall Index and Three Domains, 2024). COI may be useful in identifying how these additional factors influence sleep disturbances after concussion.

It is also important to consider the intersection between sleep and mental health and other comorbidities identified as factors for increased risk for prolonged recovery after concussion. Specifically, poor sleep has been identified as a factor for worsening depression, anxiety, migraine/headache, ADHD, and other mental health conditions (Medic et al., 2017; Vgontzas and Pavlović, 2018; Scott et al., 2021; Charest and Grandner, 2020). Similarly, those with depression, anxiety, headache/migraine, etc. have been shown to have impaired sleep or disturbed circadian rhythm (Cox and Olatunji, 2016; Steiger and Pawlowski, 2019; Oh et al., 2019). Student-athletes specifically may be at higher risk for developing a bidirectional negative feedback loop (Sin et al., 2017) because of their high rates of sleep insufficiency, propensity for developing certain sleep disorders, and extrinsic and intrinsic pressures that lend to poor mental health (Charest and Grandner, 2020; Wang and Bíró, 2021; Kroshus et al., 2019). Insufficient sleep and poor mental health can further contribute to increased risk-taking behaviors that may lead to both increased risk for injury and impaired or prolonged recovery (Charest and Grandner, 2020). Within the context of concussion, individuals with pre-existing mental health conditions are at greater risk for prolonged recovery after injury (Master et al., 2024), but the contribution of sleep to this relationship is not well understood. Due to these overlapping symptoms and etiology, it is important to better understand how sleep relates to comorbidities of concussion to inform therapeutic techniques and clinical guidance during recovery.

The goal of this study was to leverage a large pediatric and adolescent concussion registry to describe subjective reports of sleep disturbances after injury, and to examine differences in these reports across demographic and clinical characteristics. A secondary goal of the study was to explore whether self-reported sleep disturbances after concussion predict prolonged recovery past 28 days within the same cohort. For recovery specifically, we hypothesized that those self-reporting sleep disturbances would have significantly higher risk for prolonged recovery past 28 days than peers not endorsing sleep disturbances. Finally, an additional exploratory goal of this study was to understand whether comorbidities moderated the relationship between disturbed sleep and prolonged recovery.

This study provides an epidemiological analysis of patient-reported sleep disturbances among a cohort of concussed patients from a large pediatric and adolescent concussion registry. Interestingly, about 2/3 of our patients self-reported changes in sleep, a higher rate than Djukic and colleagues reported (51%; age 3–17) in a systematic review of sleep outcomes after pediatric and adolescent concussion (Djukic et al., 2022). Within the multivariate model, we also found that the presence of sleep disturbances following concussion was the second strongest predictor of prolonged recovery beyond 28 days, only behind female sex. Last, we found that comorbidities did not moderate the relationship between sleep disturbances and prolonged recovery.

There were notable differences in the subjective reporting of sleep disturbances following injury among multiple demographic characteristics and several clinical factors. First, we found sex differences where a higher percentage of females reported sleep disturbance following injury. This is supported by previous research in those 10–35 years of age who were seen within 3 days of injury, which found that after a single concussion, females have significantly increased sleep disturbance (across 4 weeks after injury) while males experience minimal change in sleep (Oyegbile et al., 2017). These findings are reflective of the higher prevalence of girls and women with sleep disorders in the general population, specifically restless leg syndrome (RLS), Rapid Eye Movement (REM) sleep disordered breathing, and insomnia (Mallampalli and Carter, 2014), and likely mirrors concussion reporting behavior where girls and women are more likely to report symptoms (McGroarty et al., 2020). Sex differences in outcomes after concussion may be driven, in part, due to sex differences in sleep, which warrant further investigation. In combination, these results suggest a need for more aggressive surveillance and treatment in young females where the effects of concussion may be more severe and prolonged (Oyegbile et al., 2017). Our research contributes to the growing body of evidence supporting the need for personalized concussion assessments, with careful consideration of factors such as sex, to ensure accurate screening, diagnosis, and treatment.

Second, we found that those who reported sleep disturbances following injury tended to be slightly older. While this finding may give credence to the thinking that younger children may be more resilient to symptom persistence following injury (Ledoux et al., 2019), this may also reflect the fact that older children and adolescents may be more in tune with their body, daily schedule, and sleep need and are better able to describe the presence of sleep disturbances after concussion. Younger children and adolescents may also have more free time to rest or nap compared to their inherently busier older peers.

Interestingly, those who reported sleep disturbance were more likely to present ~1 day later to specialty care compared to their peers without sleep disturbances. This is contrary to what might be expected, where our results show individuals with sleep disturbance have higher overall symptom burden and overlapping symptoms, which one might hypothesize may result in earlier presentation for care. This finding, however, parallels findings among sex differences in concussion and may actually be related to extrinsic factors such as access to care and scheduling availability favoring males (Desai et al., 2019).

Not surprisingly, our analysis demonstrated differences between categories of COI, specifically within the social and environmental domain and overall scores. Specifically, those that reported sleep disturbance following injury had lower social and environmental and overall scores, but not educational, which may represent a difference in housing environment, socioeconomic status, neighborhood noise, and greenspace, among others. These results are clinically important because they highlight the fact that access to care and recovery profiles following a concussion may be confounded by differences in opportunity that are magnified through systemic disparities (Wallace and Mannix, 2021). Thus, we urge clinicians to try to better understand the different environments in which their patients reside and the unique needs of those communities, and to approach clinical management and recommendations with these contexts in mind.

Regarding previous history of concussion, a greater proportion of pediatric and adolescent patients who had no previous concussion reported sleep disturbance compared to those who had a previous injury. There is conflicting data in the literature, however, where others have found that individuals with a history of repeated concussion showed a longer concussion duration and higher reported sleep disturbance following subsequent injury (Oyegbile et al., 2020). This finding may, in part, be a result of the fact that families of individuals sustaining a second concussion may be more familiar with treatment recommendation and may be more apt to begin them earlier, specifically those related to sleep hygiene that were given during care for their previous injury.

PCSI was significantly greater at initial visit for both pediatric and adolescent patients that reported sleep disturbances which may reflect that poor sleep may amplify concussion symptoms. We expected some symptom overlap since those that report sleep disturbance also tend to have co-ocurring symptoms of fatigue, poor concentration, and drowsiness, among others (DuPrey et al., 2022).

Another important finding is the prevalence of a medical history of co-occurring conditions in those reporting subjective sleep disturbance. Previous research from our group has described worsening of pre-existing mood symptoms following concussion (Master et al., 2024), but we did not find a statistical interaction between co-occurring conditions, sleep, and prolonged recovery in the multivariate model. The interaction of these variables in vivo is likely complex and individualized.

Finally, we found a difference in prevalence of sleep disturbances between groups according to the length of their clinical course (calculated as number of days from injury to final visit), with individuals that self-reported sleep disturbance after injury taking on average 16 days longer to complete their clinical course of care, which is consistent with previous literature (Bramley et al., 2017). This hypothesis was also supported by our multivariate regression analysis showing a 1.37 OR for recovery past 28 days for those who self-reported sleep disturbance after controlling for other significant variables associated with prolonged recovery. Interestingly, sleep disturbance was the strongest predictor of prolonged recovery, even moreso than other previously described and known clinical contributors to prolonged recovery such as delayed presentation for care, higher symptom burden, and presence of a learning disability. These results support the most recent concussion consensus statement review that describes patients who report sleep disturbance within the first 10 days following sport-related concussion have a higher risk for persistent symptom burden (Patricios et al., 2023), and our study extend this to increased risk for prolonged clinical recovery past 28 days. Our results report on concussions of various mechanisms, not only sport-related, and illuminate an area for improvement in clinical practice for sleep recommendations and early referral. Specifically, our findings highlight a potential interplay between sleep disturbances and sex following concussion in pediatric and adolescent patients.

Our study found that the presence of a simple self-reported sleep disturbance at initial visit post-injury was the second strongest predictor of prolonged recovery past 28 days, only behind female sex. Other predictive factors identified in our analyses—later presentation, greater symptoms, concussion history, and learning disability, confirm findings that have also been more frequently highlighted in the literature, while the effect of sex differences and sleep disturbance on concussion recovery appear to be the strongest relationships. These results have important implications for individualizing recovery strategies by adding sleep disturbance as an independent predictor. Specifically, clinicians should be aware of the high rate of sleep disturbance following injury, and the importance of sleep to overall recovery and health-related quality of life while encouraging holistic treatment of the entire individual, including their lifestyle and behaviors, as opposed to simply treating a singular condition.