Sleep, Sleep Disorders, and Mild Traumatic Brain Injury. What We Know and What We Need to Know: Findings from a National Working Group

Factors Influencing Adherence to Insomnia and Obstructive Sleep Apnea Treatments among Veterans with Mild Traumatic Brain Injury

OBJECTIVE

To understand factors influencing adherence to recommended treatment for insomnia and obstructive sleep apnea (OSA) among Veterans with mild traumatic brain injury (mTBI).

METHOD

Semi-structured interviews (n = 49) with 29 clinical stakeholders and 20 Veterans were conducted. Clinical stakeholders included Veterans Health Administration providers and policymakers involved in the management of mTBI and/or sleep disorders. Veterans included those with a clinician-confirmed mTBI with a recent history of insomnia disorder and/or OSA treatment. Themes were identified using a Descriptive and Interpretive approach.

RESULTS

Barriers to sleep disorder treatment adherence included factors associated with the patient (e.g., negative appraisal of treatment benefit), intervention (e.g., side effects), health conditions (e.g., cognitive challenges), health care system (e.g., limited availability of care), and socioeconomic status (e.g., economic instability). Similarly, facilitators of adherence included patient- (e.g., positive appraisal of treatment benefit), intervention- (e.g., flexible delivery format), condition- (e.g., accommodating cognitive impairments), health care system- (e.g., access to adherence support), and socioeconomic-related factors (e.g., social support).

CONCLUSIONS

Interviews revealed the multi-faceted nature of factors influencing adherence to sleep disorder treatment among Veterans with mTBI. Findings can inform the development of novel interventions and care delivery models that meet the complex needs of this population.

Sleep fragmentation after traumatic brain injury impairs behavior and conveys long-lasting impacts on neuroinflammation

Traumatic brain injury (TBI) causes a prolonged inflammatory response in the central nervous system (CNS) driven by microglia. Microglial reactivity is exacerbated by stress, which often provokes sleep disturbances. We have previously shown that sleep fragmentation (SF) stress after experimental TBI increases microglial reactivity and impairs hippocampal function 30 days post-injury (DPI). The neuroimmune response is highly dynamic the first few weeks after TBI, which is also when injury induced sleep-wake deficits are detected. Therefore, we hypothesized that even a few weeks of TBI SF stress would synergize with injury induced sleep-wake deficits to promote neuroinflammation and impair outcome. Here, we investigated the effects of environmental SF in a lateral fluid percussion model of mouse TBI. Half of the mice were undisturbed, and half were exposed to 5 h of SF around the onset of the light cycle, daily, for 14 days. All mice were then undisturbed 15-30 DPI, providing a period for SF stress recovery (SF-R). Mice exposed to SF stress slept more than those in control housing 7-14 DPI and engaged in more total daily sleep bouts during the dark period. However, SF stress did not exacerbate post-TBI sleep deficits. Testing in the Morris water maze revealed sex dependent differences in spatial reference memory 9-14 DPI with males performing worse than females. Post-TBI SF stress suppressed neurogenesis-related gene expression and increased inflammatory signaling in the cortex at 14 DPI. No differences in sleep behavior were detected between groups during the SF stress recovery period 15-30 DPI. Microscopy revealed cortical and hippocampal IBA1 and CD68 percent-area increased in TBI SF-R mice 30 DPI. Additionally, neuroinflammatory gene expression was increased, and synaptogenesis-related gene expression was suppressed in TBI-SF mice 30 DPI. Finally, IPA canonical pathway analysis showed post-TBI SF impaired and delayed activation of synapse-related pathways between 14 and 30 DPI. These data show that transient SF stress after TBI impairs recovery and conveys long-lasting impacts on neuroimmune function independent of continuous sleep deficits. Together, these finding support that even limited exposure to post-TBI SF stress can have lasting impacts on cognitive recovery and regulation of the immune response to trauma.

Longitudinal Assessment of Glymphatic Changes Following Mild Traumatic Brain Injury: Insights from PVS burden and DTI-ALPS Imaging

Traumatic brain injury (TBI) even in the mild form may result in long-lasting post-concussion symptoms. TBI is also a known risk to late-life neurodegeneration. Recent studies suggest that dysfunction in the glymphatic system, responsible for clearing protein waste from the brain, may play a pivotal role in the development of dementia following TBI. Given the diverse nature of TBI, longitudinal investigations are essential to comprehending the dynamic changes in the glymphatic system and its implications for recovery. In this prospective study, we evaluated two promising glymphatic imaging markers, namely the enlarged perivascular space (ePVS) burden and Diffusion Tensor Imaging-based ALPS index, in 44 patients with mTBI at two early post-injury time points: approximately 14 days (14Day) and 6-12 months (6-12Mon) post-injury, while also examining their associations with post-concussion symptoms. Additionally, 37 controls, comprising both orthopedic patients and healthy individuals, were included for comparative analysis. Our key findings include: 1) White matter ePVS burden (WM-ePVS) and ALPS index exhibit significant correlations with age. 2) Elevated WM-ePVS burden in acute mTBI (14Day) is significantly linked to a higher number of post-concussion symptoms, particularly memory problems. 3) The increase in the ALPS index from acute (14Day) to the chronic (6-12Mon) phases in mTBI patients correlates with improvement in sleep measures. Furthermore, incorporating WM-ePVS burden and the ALPS index from acute phase enhances the prediction of chronic memory problems beyond socio-demographic and basic clinical information, highlighting their distinct roles in assessing glymphatic structure and activity. Early evaluation of glymphatic function could be crucial for understanding TBI recovery and developing targeted interventions to improve patient outcomes.

A randomized clinical trial for a self-guided sleep intervention following moderate-severe traumatic brain injury: Study protocol

BACKGROUND

Individuals with a history of moderate-severe traumatic brain injury (TBI) experience a significantly higher prevalence of insomnia compared to the general population. While individuals living with TBI have been shown to benefit from traditional insomnia interventions (e.g., face-to-face [F2F]), such as Cognitive Behavioral Therapy for Insomnia (CBTI), many barriers exist that limit access to F2F evidence-based treatments. Although computerized CBT-I (CCBT-I) is efficacious in terms of reducing insomnia symptoms, individuals with moderate-severe TBI may require support to engage in such treatment. Here we describe the rationale, design, and methods of a randomized controlled trial (RCT) assessing the efficacy of a guided CCBT-I program for reducing insomnia symptoms for participants with a history of moderate-severe TBI.

METHODS

This is an RCT of a guided CCBT-I intervention for individuals with a history of moderate-severe TBI and insomnia. The primary outcome is self-reported insomnia severity, pre- to post-intervention. Exploratory outcomes include changes in sleep misperception following CCBT-I and describing the nature of guidance needed by the Study Clinician during the intervention.

CONCLUSION

This study represents an innovative approach to facilitating broader engagement with an evidence-based online treatment for insomnia among those with a history of moderate-severe TBI. Findings will provide evidence for the level and nature of support needed to implement guided CCBT-I. Should findings be positive, this study would provide support for a strategy by which to deliver guided CCBT-I to individuals with a history of moderate-severe TBI.

Sleep Disruption Persists and Relates to Memory Disability After Traumatic Brain Injury: A Cross-Sectional Study of Adults in the Chronic Phase of Injury

OBJECTIVE

To examine sleep disruption in chronic traumatic brain injury (TBI) across 3 aims: (1) to examine differences in self-reported sleep disruption between adults with and without a chronic history of TBI; (2) to query reported changes in sleep after TBI; and (3) to explore the relationship between self-reported sleep disruption and memory failures in daily life.

SETTING

Community-dwelling participants completed self-report sleep and memory surveys as part of their participation in a larger patient registry.

PARTICIPANTS

This study included 258 participants, and half (n = 129) of them have a chronic history of moderate-severe TBI (mean time since injury is 5.1 [SD 6.5] years).

DESIGN

We report descriptive statistics from this matched cross-sectional study on sleep in the chronic phase of injury. We also used planned Wilcoxon ranked-sum tests and exploratory correlations to examine the relationships of sleep disruption with TBI diagnosis, injury chronicity, and memory.

MAIN MEASURES

We used the Pittsburgh Sleep Quality Index to measure sleep disruption and the Epworth Sleepiness Scale to measure daytime sleepiness. Participants answered questions about postinjury sleep and responded to the Everyday Memory Questionnaire as a measure of memory failures in daily life.

RESULTS

Individuals with TBI had significantly higher rates of sleep disruption than those without TBI, as measured by the Pittsburgh Sleep Quality Index but not on the Epworth Sleepiness Scale. Sleep disruption in TBI manifested more in sleep quality than quantity. Half of the participants with TBI reported a negative change in sleep postinjury. In an exploratory analysis, sleep disruption was related to memory failure in daily life in the TBI sample.

CONCLUSIONS

Sleep disruption persists long after TBI but may be under-recognized in people with chronic TBI. Given that sleep is critical for memory and rehabilitation outcomes well into the chronic phase of injury, steps to improve the identification and management of sleep disruption are needed. Key words:chronic, memory, sleep, traumatic brain injury.

Investigation of Mild Traumatic Brain Injury Home Cage Behavior: The Home Cage Assay Advantages

This study utilized the Noldus PhenoTyper Home Cage Monitoring system (HCM) to assess the behavioral and cognitive changes of experimental closed-head mild traumatic brain injury (mTBI). Seventy-nine adult male Institute of Cancer Research (ICR) mice were subjected to either a sham procedure or closed-head mTBI using the weight-drop model. Seven days post-injury, separate cohorts of mice underwent either a non-cognitive or a cognitive home cage assessment, a treadmill fatigue test, or the Open Field Test. mTBI significantly influenced habituation behavior and circadian wheel-running activity. Notably, mTBI mice exhibited an increased frequency of visits to the running wheel, but each visit was shorter than those of controls. No significant differences between the groups in discrimination or reversal learning performance were observed. However, during the reversal learning stage, mTBI mice performed similarly to their initial discrimination learning levels, suggesting an abnormally faster rate of reversal learning. Home cage monitoring is a valuable tool for studying the subtle effects of mTBI, complementing traditional assays. The automated evaluation of habituation to novel stimuli (e.g., novel environment) could serve as a potentially sensitive tool for assessing mTBI-associated behavioral deficits.

Sleep, inflammation, and hemodynamics in rodent models of traumatic brain injury

Traumatic brain injury (TBI) can induce dysregulation of sleep. Sleep disturbances include hypersomnia and hyposomnia, sleep fragmentation, difficulty falling asleep, and altered electroencephalograms. TBI results in inflammation and altered hemodynamics, such as changes in blood brain barrier permeability and cerebral blood flow. Both inflammation and altered hemodynamics, which are known sleep regulators, contribute to sleep impairments post-TBI. TBIs are heterogenous in cause and biomechanics, which leads to different molecular and symptomatic outcomes. Animal models of TBI have been developed to model the heterogeneity of TBIs observed in the clinic. This review discusses the intricate relationship between sleep, inflammation, and hemodynamics in pre-clinical rodent models of TBI.

Sleep loss, caffeine, sleep aids and sedation modify brain abnormalities of mild traumatic brain injury

Little evidence exists about how mild traumatic brain injury (mTBI) is affected by commonly encountered exposures of sleep loss, sleep aids, and caffeine that might be potential therapeutic opportunities. In addition, while propofol sedation is administered in severe TBI, its potential utility in mild TBI is unclear. Each of these exposures is known to have pronounced effects on cerebral metabolism and blood flow and neurochemistry. We hypothesized that they each interact with cerebral metabolic dynamics post-injury and change the subclinical characteristics of mTBI. MTBI in rats was produced by head rotational acceleration injury that mimics the biomechanics of human mTBI. Three mTBIs spaced 48 h apart were used to increase the likelihood that vulnerabilities induced by repeated mTBI would be manifested without clinically relevant structural damage. After the third mTBI, rats were immediately sleep deprived or administered caffeine or suvorexant (an orexin antagonist and sleep aid) for the next 24 h or administered propofol for 5 h. Resting state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI) were performed 24 h after the third mTBI and again after 30 days to determine changes to the brain mTBI phenotype. Multi-modal analyses on brain regions of interest included measures of functional connectivity and regional homogeneity from rs-fMRI, and mean diffusivity (MD) and fractional anisotropy (FA) from DTI. Each intervention changed the mTBI profile of subclinical effects that presumably underlie healing, compensation, damage, and plasticity. Sleep loss during the acute post-injury period resulted in dramatic changes to functional connectivity. Caffeine, propofol sedation and suvorexant were especially noteworthy for differential effects on microstructure in gray and white matter regions after mTBI. The present results indicate that commonplace exposures and short-term sedation alter the subclinical manifestations of repeated mTBI and therefore likely play roles in symptomatology and vulnerability to damage by repeated mTBI.

Identifying and Predicting Subgroups of Veterans With Mild Traumatic Brain Injury Based on Distinct Configurations of Postconcussive Symptom Endorsement: A Latent Class Analysis

OBJECTIVE

To identify distinct subgroups of veterans with mild traumatic brain injury (mTBI) based on configurations of postconcussive symptom (PCS) endorsement, and to examine predictors of subgroup membership.

SETTING

Outpatient Veterans Health Administration (VHA).

PARTICIPANTS

Veterans with clinician-confirmed mTBI who completed the Neurobehavioral Symptom Inventory (NSI), determined using the Comprehensive Traumatic Brain Injury Evaluation database. Individuals who tended to overreport symptoms were excluded via an embedded symptom validity scale.

DESIGN

Retrospective cohort study leveraging national VHA clinical data from 2012 to 2020. Latent class analysis (LCA) with a split-sample cross-validation procedure was used to identify subgroups of veterans. Multinomial logistic regression was used to examine predictors of subgroup membership.

MAIN MEASURES

Latent classes identified using NSI items.

RESULTS

The study included 72 252 eligible veterans, who were primarily White (73%) and male (94%). The LCA supported 7 distinct subgroups of veterans with mTBI, characterized by diverging patterns of risk for specific PCS across vestibular (eg, dizziness), somatosensory (eg, headache), cognitive (eg, forgetfulness), and mood domains (eg, anxiety). The most prevalent subgroup was Global (20.7%), followed by Cognitive-Mood (16.3%), Headache-Cognitive-Mood (H-C-M; 16.3%), Headache-Mood (14.2%), Anxiety (13.8%), Headache-Sleep (10.3%), and Minimal (8.5%). The Global class was used as the reference class for multinomial logistic regression because it was distinguished from others based on elevated risk for PCS across all domains. Female (vs male), Black (vs White), and Hispanic veterans (vs non-Hispanic) were less likely to be members of most subgroups characterized by lesser PCS endorsement relative to the Global class (excluding Headache-Mood).

CONCLUSION

The 7 distinct groups identified in this study distill heterogenous patterns of PCS endorsement into clinically actionable phenotypes that can be used to tailor clinical management of veterans with mTBI. Findings reveal empirical support for potential racial, ethnic, and sex-based disparities in PCS among veterans, informing efforts aimed at promoting equitable recovery from mTBI in this population.

Associations of Chronic Pain With Psychosocial Outcomes After Traumatic Brain Injury: A NIDILRR and VA TBI Model Systems Collaborative Project

OBJECTIVE

To examine the differences in participation, life satisfaction, and psychosocial outcomes among individuals with traumatic brain injury (TBI) endorsing current, past, or no chronic pain.

SETTING

Community.

PARTICIPANTS

Three thousand eight hundred four TBI Model Systems participants 1 to 30 years of age postinjury classified into 1 of 3 groups based on their pain experience: current pain, past pain, no pain completed a Pain Survey at their usual follow-up appointment which on average was approximately 8 years postinjury.

DESIGN

Multisite, cross-sectional observational cohort study.

MAIN OUTCOME MEASURES

Sociodemographic and injury characteristics and psychosocial outcomes (ie, satisfaction with life, depression, anxiety, posttraumatic stress disorder [PTSD], sleep quality, community participation).

RESULTS

Persons with current chronic pain demonstrated higher scores on measures of PTSD, anxiety, and depression, and the lower scores on measures of sleep quality, community participation and satisfaction with life. Those with resolved past pain had mean scores for these outcomes that were all between the current and no chronic pain groups, but always closest to the no pain group. After adjusting for sociodemographic and function in multivariate analysis, having current chronic pain was associated with more negative psychosocial outcomes. The largest effect sizes (ES; in absolute value) were observed for the PTSD, depression, anxiety, and sleep quality measures (ES = 0.52-0.81) when comparing current pain to past or no pain, smaller ES were observed for life satisfaction (ES = 0.22-0.37) and out and about participation (ES = 0.16-0.18). When comparing past and no pain groups, adjusted ES were generally small for life satisfaction, PTSD, depression, anxiety, and sleep quality (ES = 0.10-0.23) and minimal for participation outcomes (ES = 0.02-0.06).

CONCLUSIONS

Chronic pain is prevalent among individuals with TBI and is associated with poorer psychosocial outcomes, especially for PTSD, depression, anxiety, and sleep disturbance. The results from this study highlight the presence of modifiable comorbidities among those with chronic pain and TBI. Persons who experience persistent pain following TBI may be at greater risk for worse psychosocial outcomes.

Association Between Insomnia and Mental Health and Neurocognitive Outcomes Following Traumatic Brain Injury

We previously described five trajectories of insomnia (each defined by a distinct pattern of insomnia severity over 12 months following traumatic brain injury [TBI]). Our objective in the present study was to estimate the association between insomnia trajectory status and trajectories of mental health and neurocognitive outcomes during the 12 months after TBI. In this study, participants included N = 2022 adults from the Federal Inter-agency Traumatic Brain Injury Repository database and Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study. The following outcome measures were assessed serially at 2 weeks, and 3, 6, and 12 months post-injury: Insomnia Severity Index, Patient Health Questionnaire, Post-Traumatic Stress Disorder (PTSD) Checklist for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), Patient Reported Outcomes Measurement Information System-Pain, and Quality of Life After Brain Injury-Overall Scale. Neurocognitive performance was assessed at 2 weeks, and 6 and 12 months using the Wechsler Adult Intelligence Scales Processing Speed Index and the Trails Making Test Parts A and B. Results indicated that greater insomnia severity was associated with greater abnormality in mental health, quality of life, and neuropsychological testing outcomes. The pattern of insomnia over time tracked the temporal pattern of all these outcomes for all but a very small number of participants. Notably, severe insomnia at 3 or 6 months post-TBI was a risk factor for poor recovery at 12 months post-injury. In conclusion, in this well-characterized sample of individuals with TBI, insomnia severity generally tracked severity of depression, pain, PTSD, quality of life, and neurocognitive outcomes over 12 months post-injury. More intensive sleep assessment is needed to elucidate the nature of these relationships and to help inform best strategies for intervention.

Military-related mild traumatic brain injury: clinical characteristics, advanced neuroimaging, and molecular mechanisms

Mild traumatic brain injury (mTBI) is a significant health burden among military service members. Although mTBI was once considered relatively benign compared to more severe TBIs, a growing body of evidence has demonstrated the devastating neurological consequences of mTBI, including chronic post-concussion symptoms and deficits in cognition, memory, sleep, vision, and hearing. The discovery of reliable biomarkers for mTBI has been challenging due to under-reporting and heterogeneity of military-related mTBI, unpredictability of pathological changes, and delay of post-injury clinical evaluations. Moreover, compared to more severe TBI, mTBI is especially difficult to diagnose due to the lack of overt clinical neuroimaging findings. Yet, advanced neuroimaging techniques using magnetic resonance imaging (MRI) hold promise in detecting microstructural aberrations following mTBI. Using different pulse sequences, MRI enables the evaluation of different tissue characteristics without risks associated with ionizing radiation inherent to other imaging modalities, such as X-ray-based studies or computerized tomography (CT). Accordingly, considering the high morbidity of mTBI in military populations, debilitating post-injury symptoms, and lack of robust neuroimaging biomarkers, this review (1) summarizes the nature and mechanisms of mTBI in military settings, (2) describes clinical characteristics of military-related mTBI and associated comorbidities, such as post-traumatic stress disorder (PTSD), (3) highlights advanced neuroimaging techniques used to study mTBI and the molecular mechanisms that can be inferred, and (4) discusses emerging frontiers in advanced neuroimaging for mTBI. We encourage multi-modal approaches combining neuropsychiatric, blood-based, and genetic data as well as the discovery and employment of new imaging techniques with big data analytics that enable accurate detection of post-injury pathologic aberrations related to tissue microstructure, glymphatic function, and neurodegeneration. Ultimately, this review provides a foundational overview of military-related mTBI and advanced neuroimaging techniques that merit further study for mTBI diagnosis, prognosis, and treatment monitoring.

Machine learning-based classification of chronic traumatic brain injury using hybrid diffusion imaging

Background and purpose

Traumatic brain injury (TBI) can cause progressive neuropathology that leads to chronic impairments, creating a need for biomarkers to detect and monitor this condition to improve outcomes. This study aimed to analyze the ability of data-driven analysis of diffusion tensor imaging (DTI) and neurite orientation dispersion imaging (NODDI) to develop biomarkers to infer symptom severity and determine whether they outperform conventional T1-weighted imaging.

Materials and methods

A machine learning-based model was developed using a dataset of hybrid diffusion imaging of patients with chronic traumatic brain injury. We first extracted the useful features from the hybrid diffusion imaging (HYDI) data and then used supervised learning algorithms to classify the outcome of TBI. We developed three models based on DTI, NODDI, and T1-weighted imaging, and we compared the accuracy results across different models.

Results

Compared with the conventional T1-weighted imaging-based classification with an accuracy of 51.7-56.8%, our machine learning-based models achieved significantly better results with DTI-based models at 58.7-73.0% accuracy and NODDI with an accuracy of 64.0-72.3%.

Conclusion

The machine learning-based feature selection and classification algorithm based on hybrid diffusion features significantly outperform conventional T1-weighted imaging. The results suggest that advanced algorithms can be developed for inferring symptoms of chronic brain injury using feature selection and diffusion-weighted imaging.

The glymphatic system's role in traumatic brain injury-related neurodegeneration

In at least some individuals who suffer a traumatic brain injury (TBI), there exists a risk of future neurodegenerative illness. This review focuses on the association between the brain-based paravascular drainage pathway known as the "glymphatic system" and TBI-related neurodegeneration. The glymphatic system is composed of cerebrospinal fluid (CSF) flowing into the brain parenchyma along paravascular spaces surrounding penetrating arterioles where it mixes with interstitial fluid (ISF) before being cleared along paravenous drainage pathways. Aquaporin-4 (AQP4) water channels on astrocytic end-feet appear essential for the functioning of this system. The current literature linking glymphatic system disruption and TBI-related neurodegeneration is largely based on murine models with existing human research focused on the need for biomarkers of glymphatic system function (e.g., neuroimaging modalities). Key findings from the existing literature include evidence of glymphatic system flow disruption following TBI, mechanisms of this decreased flow (i.e., AQP4 depolarization), and evidence of protein accumulation and deposition (e.g., amyloid β, tau). The same studies suggest that glymphatic dysfunction leads to subsequent neurodegeneration, cognitive decline, and/or behavioral change although replication in humans is needed. Identified emerging topics from the literature are as follows: link between TBI, sleep, and glymphatic system dysfunction; influence of glymphatic system disruption on TBI biomarkers; and development of novel treatments for glymphatic system disruption following TBI. Although a burgeoning field, more research is needed to elucidate the role of glymphatic system disruption in TBI-related neurodegeneration.

Does Sleep Quality Influence Recovery Outcomes After Postconcussive Injury in Children and Adolescents?

OBJECTIVE

To determine whether objective parameters of sleep quality differ throughout recovery between children and adolescents who experienced an early return to school (RTS) and those who had a delayed RTS or did not return at all during the study period.

SETTING

Sleep parameters reflective of sleep quality were evaluated in participants' natural sleeping habitat throughout 9 weeks postinjury.

PARTICIPANTS

Ninety-four children and adolescents (aged 5-18 years) with diagnosed concussion.

DESIGN

Prospective cohort. Participants followed RTS protocols.

MAIN MEASURES

Actigraphy-derived estimates of total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), average arousal length (AAL), and number of arousals (NOAs) per hour were assessed. The length of time from injury until RTS was determined for each participant. Participants were categorized into an early RTS or delayed RTS group based on their time to RTS.

RESULTS

Both TST and SE were significantly greater in the early RTS group. WASO duration, AAL, and NOAs were significantly greater in the delayed RTS group. Differences between RTS groups were most apparent during weeks 1 to 5 postinjury.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Participants who returned to school earlier had significantly better objective sleep quality than participants who experienced a delayed RTS. This study provides evidence in support of a relationship between sleep quality and time to RTS in children and adolescents with concussion. Considering early monitoring of sleep, education regarding sleep hygiene, and access to age-appropriate sleep interventions may be helpful in pediatric concussion recovery.

Hierarchical clustering of prolonged post-concussive symptoms after 12 months: symptom-centric analysis and association with functional impairments

BACKGROUND

Following a concussion, approximately 15% of individuals experience persistent symptoms that can lead to functional deficits. However, underlying symptom-clusters that persist beyond 12 months have not been adequately characterized, and their relevance to functional deficits are unclear. The aim of this study was to characterize the underlying clusters of prolonged post-concussive symptoms lasting more than 12 months, and to investigate their association with functional impairments.

METHODS

Although hierarchical clustering is ideally suited in evaluating subjective symptom severities, it has not been applied to the Rivermead Post-Concussion Questionnaire (RPQ). The RPQ and functional impairments questions were administered via a smartphone application to 445 individuals who self-reported prolonged post-concussive symptoms. Symptom-clusters were obtained using agglomerative hierarchical clustering, and their association with functional deficits were investigated with sensitivity analyses, and corrected for multiple comparisons.

RESULTS

Five symptom-clusters were identified: headache-related, sensitivity to light and sound, cognitive, mood-related, and sleep-fatigue. Individuals with more severe RPQ symptoms were more likely to report functional deficits (p < 0.0001). Whereas the headache and sensitivity clusters were associated with at most one impairment, at-least-mild sleeping difficulties and fatigue were associated with four, and moderate-to-severe cognitive difficulties with five (all p < 0.01).

CONCLUSIONS

Symptom-clusters may be clinically useful for functional outcome stratification for targeted rehabilitation therapies. Further studies are required to replicate these findings in other cohorts and questionnaires, and to ascertain the effects of symptomatic intervention on functional outcomes.

Sex predicts post-concussion symptom reporting, independently of fatigue and subjective sleep disturbance, in premorbidly healthy adults after mild traumatic brain injury

The relationship between sex and post-concussion symptom (PCS) reporting after mild traumatic brain injury (mTBI) is not well understood. Subjective sleep disturbance and fatigue impact PCS reporting after mTBI and show sex differences in the normal population. This study investigated whether sex had a relationship with PCS reporting after mTBI, independently of self-reported sleep disturbance and fatigue. Ninety-two premorbidly healthy adults in the post-acute period after mTBI completed the Rivermead Post-Concussion Symptoms Questionnaire, the Pittsburgh Sleep Quality Index, the Multidimensional Fatigue Inventory and measures of depression, anxiety and post-traumatic stress symptomatology. Females (n = 23) demonstrated higher levels of fatigue (p = .019) and greater psychological distress (p = .001) than males (n = 69), but equivalent levels of sleep disturbance (p = .946). Bootstrapping analyses were undertaken because PCS responses were not normally distributed. Female sex predicted greater PCS reporting (p = .001), independently of subjective sleep disturbance, fatigue, psychological distress and litigation status. The current findings support and extend previous work showing premorbidly healthy females are at higher risk of experiencing elevated PCS after mTBI than males in the post-acute period after mTBI. It may be beneficial for clinicians to be particularly sensitive to increased symptom reporting after mTBI in females, irrespective of sleep quality, fatigue or psychological status.

Post-concussive symptoms mediate the relationship between sleep problems and participation restrictions among veterans with mild traumatic brain injury

Background

Sleep problems are common among Veterans with mild traumatic brain injury (mTBI) and may contribute to participation restrictions. However, explanatory mechanisms underlying this relationship are poorly understood. Sleep problems are associated with post-concussive symptoms (e.g., headaches). In turn, post-concussive symptoms contribute to participation restrictions. We hypothesized that post-concussive symptom severity mediates the purported relationship between sleep problems and participation restrictions among Veterans with mTBI.

Materials and Methods

This study was a retrospective analysis of clinical data among 8,733 Veterans with mTBI receiving Veterans Health Administration outpatient care. Sleep problems (yes/no) were identified using the sleep-related item from the Neurobehavioral Symptom Inventory (NSI). Post-concussive symptoms were measured using remaining NSI items. Participation restrictions were measured using the Mayo-Portland Adaptability Inventory Participation Index. We specified a latent variable path model to estimate relationships between: (1) sleep problems and three latent indicators of post-concussive symptoms [vestibular-sensory (e.g., headache)]; mood-behavioral [e.g., anxiety]; cognitive [e.g., forgetfulness]); and, (2) the three latent indicators of post-concussive symptoms and two latent indicators of participation restrictions (social and community participation [e.g., leisure activities]; productivity [e.g., financial management]). We examined the indirect effects of sleep problems upon participation restrictions, as mediated by post-concussive symptoms. Estimates were adjusted for sociodemographic factors (e.g., age), injury characteristics (e.g., blast), and co-morbid conditions (e.g., depression).

Results

87% of Veterans reported sleep problems. Sleep problems were associated with greater social and community participation restrictions, as mediated by mood-behavioral (β = 0.41, p < 0.001) and cognitive symptoms (β = 0.13, p < 0.001). There was no evidence that vestibular-sensory symptoms mediated this relationship (β = -0.01, p = 0.48). Sleep problems were associated with greater productivity restrictions, as mediated by vestibular-sensory (β = 0.16, p < 0.001) and cognitive symptoms (β = 0.14, p < 0.001). There was no evidence that mood-behavioral symptoms mediated this relationship (β = 0.02, p = 0.37).

Discussion

Findings suggest that evidence-based sleep treatment should occupy a prominent role in the rehabilitation of Veterans with mTBI. Indirect effects of sleep problems differed when considering impact on social and community participation vs. productivity, informing individualized rehabilitative care for Veterans with mTBI.

Assessing Cognitive Behavioral Therapy for Insomnia to Improve Sleep Outcomes in Individuals With a Concussion: Protocol for a Delayed Randomized Controlled Trial

BACKGROUND

Sleep disturbances post concussion have been associated with more frequent and severe concussion symptoms and may contribute to poorer recovery. Cognitive behavioral therapy for insomnia (CBT-I) is an effective treatment for insomnia; however, it remains unclear if this treatment method is effective in improving sleep outcomes and reducing concomitant postconcussion symptoms.

OBJECTIVE

The hypotheses for this study are that (1) CBT-I will improve sleep outcomes and (2) CBT-I will improve concomitant postconcussion symptoms.

METHODS

In total, 40 individuals who are within ≥4 weeks of postconcussion injury and have insomnia symptoms will be enrolled in this randomized controlled trial. Participants will be randomized into either a group that starts a 6-week CBT-I program immediately after baseline or a waitlist control group that starts CBT-I following a 6-week waiting period. All participants will be reassessed 6, 12, and 18 weeks after baseline. Standardized assessments measuring sleep outcomes, postconcussion symptoms, and mood will be used. Linear regression and t tests will be used for statistical analyses.

RESULTS

Enrollment of 40 participants was completed July 2022, data collection will be completed in November 2022, and publication of main findings is anticipated in May 2023. It is anticipated that participants experience reduced insomnia symptoms and postconcussion symptoms following CBT-I and these improvements will be retained for at least 12 weeks. Additionally, we expect to observe a positive correlation between sleep and postconcussion symptom improvement.

CONCLUSIONS

Successful completion of this pilot study will allow for a better understanding of the treatment of insomnia and postconcussion symptoms in individuals following a concussion.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04885205; https://clinicaltrials.gov/ct2/show/NCT04885205.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/38608.

The Effect of Traumatic Brain Injury on Sleep Architecture and Circadian Rhythms in Mice—A Comparison of High-Frequency Head Impact and Controlled Cortical Injury

Simple Summary

Traumatic brain injury (TBI) is a significant risk factor for the development of sleep and circadian rhythm impairments. In order to understand if TBI models with different injury mechanism, severity and pathology have different sleep and circadian rhythm disruptions, we performed a detailed sleep and circadian analysis of the high-frequency head impact TBI model (a mouse model that mimics sports-related head impacts) and the controlled cortical impact TBI model (a mouse model that mimics severe brain trauma). We found that both TBI models disrupt the ability of brain cells to maintain circadian rhythms; however, both injury groups could still maintain circadian behavior patterns. Both the mild head impact model and the severe brain injury model had normal amount of sleep at 7 d after injury; however, the severe brain injury mice had disrupted brain wave patterns during sleep. We conclude that different types of TBI have different patterns of sleep disruptions.

Abstract

Traumatic brain injury (TBI) is a significant risk factor for the development of sleep and circadian rhythm impairments. In this study we compare the circadian rhythms and sleep patterns in the high-frequency head impact (HFHI) and controlled cortical impact (CCI) mouse models of TBI. These mouse models have different injury mechanisms key differences of pathology in brain regions controlling circadian rhythms and EEG wave generation. We found that both HFHI and CCI caused dysregulation in the diurnal expression of core circadian genes (Bmal1, Clock, Per1,2, Cry1,2) at 24 h post-TBI. CCI mice had reduced locomotor activity on running wheels in the first 7 d post-TBI; however, both CCI and HFHI mice were able to maintain circadian behavior cycles even in the absence of light cues. We used implantable EEG to measure sleep cycles and brain activity and found that there were no differences in the time spent awake, in NREM or REM sleep in either TBI model. However, in the sleep states, CCI mice have reduced delta power in NREM sleep and reduced theta power in REM sleep at 7 d post-TBI. Our data reveal that different types of brain trauma can result in distinct patterns of circadian and sleep disruptions and can be used to better understand the etiology of sleep disorders after TBI.

Sleep Disorders in Traumatic Brain Injury

SUMMARY

Sleep disorders are common after traumatic brain injury (TBI). This study will review the spectrum and proposed mechanisms of TBI-associated sleep disorders and discuss the clinical approach to diagnosis and management of them. Disordered and fragmented sleep with insomnia and daytime sleepiness is very common after TBI. Sleep disruption contributes to morbidity and neurocognitive and neurobehavioral deficits and prolongs the recovery phase after injury. Early recognition and correction of these problems may limit the secondary effects of TBI and improve patient outcomes. Evaluating sleep disorders in TBI should be an important component of TBI assessment and management. Finally, newer research techniques for early diagnosis, prognosis, and improved outcomes after TBI will also be addressed.

Association of Traumatic Brain Injury With the Risk of Developing Chronic Cardiovascular, Endocrine, Neurological, and Psychiatric Disorders

IMPORTANCE

Increased risk of neurological and psychiatric conditions after traumatic brain injury (TBI) is well-defined. However, cardiovascular and endocrine comorbidity risk after TBI in individuals without these comorbidities and associations with post-TBI mortality have received little attention.

OBJECTIVE

To assess the incidence of cardiovascular, endocrine, neurological, and psychiatric comorbidities in patients with mild TBI (mTBI) or moderate to severe TBI (msTBI) and analyze associations between post-TBI comorbidities and mortality.

DESIGN, SETTING, AND PARTICIPANTS

This prospective longitudinal cohort study used hospital-based patient registry data from a tertiary academic medical center to select patients without any prior clinical comorbidities who experienced TBI from 2000 to 2015. Using the same data registry, individuals without head injuries, the unexposed group, and without target comorbidities were selected and age-, sex-, and race-frequency-matched to TBI subgroups. Patients were followed-up for up to 10 years. Data were analyzed in 2021.

EXPOSURES

Mild or moderate to severe head trauma.

MAIN OUTCOMES AND MEASURES

Cardiovascular, endocrine, neurologic, and psychiatric conditions were defined based on International Classification of Diseases, Ninth Revision (ICD-9) or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10). Associations between TBI and comorbidities, as well as associations between the comorbidities and mortality, were analyzed.

RESULTS

A total of 4351 patients with mTBI (median [IQR] age, 45 [29-57] years), 4351 patients with msTBI (median [IQR] age, 47 [30-58] years), and 4351 unexposed individuals (median [IQR] age, 46 [30-58] years) were included in analyses. In each group, 45% of participants were women. mTBI and msTBI were significantly associated with higher risks of cardiovascular, endocrine, neurologic, and psychiatric disorders compared with unexposed individuals. In particular, hypertension risk was increased in both mTBI (HR, 2.5; 95% CI, 2.1-2.9) and msTBI (HR, 2.4; 95% CI, 2.0-2.9) groups. Diabetes risk was increased in both mTBI (HR, 1.9; 95% CI, 1.4-2.7) and msTBI (HR, 1.9; 95% CI, 1.4-2.6) groups, and risk of ischemic stroke or transient ischemic attack was also increased in mTBI (HR, 2.2; 95% CI, 1.4-3.3) and msTBI (HR, 3.6; 95% CI, 2.4-5.3) groups. All comorbidities in the TBI subgroups emerged within a median (IQR) of 3.49 (1.76-5.96) years after injury. Risks for post-TBI comorbidities were also higher in patients aged 18 to 40 years compared with age-matched unexposed individuals: hypertension risk was increased in the mTBI (HR, 5.9; 95% CI, 3.9-9.1) and msTBI (HR, 3.9; 95% CI, 2.5-6.1) groups, while hyperlipidemia (HR, 2.3; 95% CI, 1.5-3.4) and diabetes (HR, 4.6; 95% CI, 2.1-9.9) were increased in the mTBI group. Individuals with msTBI, compared with unexposed patients, had higher risk of mortality (432 deaths [9.9%] vs 250 deaths [5.7%]; P < .001); postinjury hypertension (HR, 1.3; 95% CI, 1.1-1.7), coronary artery disease (HR, 2.2; 95% CI, 1.6-3.0), and adrenal insufficiency (HR, 6.2; 95% CI, 2.8-13.0) were also associated with higher mortality.

CONCLUSIONS AND RELEVANCE

These findings suggest that TBI of any severity was associated with a higher risk of chronic cardiovascular, endocrine, and neurological comorbidities in patients without baseline diagnoses. Medical comorbidities were observed in relatively young patients with TBI. Comorbidities occurring after TBI were associated with higher mortality. These findings suggest the need for a targeted screening program for multisystem diseases after TBI, particularly chronic cardiometabolic diseases.

The Bidirectional Link Between Sleep Disturbances and Traumatic Brain Injury Symptoms: A Role for Glymphatic Dysfunction?

Mild traumatic brain injury (mTBI), often referred to as concussion, is a major cause of morbidity and mortality worldwide. Sleep disturbances are common after mTBI. Moreover, subjects who develop subjective sleep complaints after mTBI also report more severe somatic, mental health, and cognitive impairment and take longer to recover from mTBI sequelae. Despite many previous studies addressing the role of sleep in post-mTBI morbidity, the mechanisms linking sleep to recovery after mTBI remain poorly understood. The glymphatic system is a brainwide network that supports fluid movement through the cerebral parenchyma and the clearance of interstitial solutes and wastes from the brain. Notably, the glymphatic system is active primarily during sleep. Clearance of cellular byproducts related to somatic, mental health, and neurodegenerative processes (e.g., amyloid-β and tau, among others) depends in part on intact glymphatic function, which becomes impaired after mTBI. In this viewpoint, we review the current knowledge regarding the association between sleep disturbances and post-mTBI symptoms. We also discuss the role of glymphatic dysfunction as a potential link between mTBI, sleep disruption, and posttraumatic morbidity. We outline a model where glymphatic dysfunction and sleep disruption caused by mTBI may have an additive effect on waste clearance, leading to cerebral dysfunction and impaired recovery. Finally, we review the novel techniques being developed to examine glymphatic function in humans and explore potential interventions to alter glymphatic exchange that may offer a novel therapeutic approach to those experiencing poor sleep and prolonged symptoms after mTBI.

Examining the trajectory and predictors of post-concussion sleep quality in children and adolescents

OBJECTIVES

This study aimed to 1) determine if post-concussion sleep quality of children and adolescents differed from healthy sleep estimates; 2) describe the trajectory of parameters of sleep quality; 3) determine factors that predict sleep quality outcomes; and 4) compare sleep parameter outcomes between asymptomatic and symptomatic participants at 4 weeks post-concussion.

METHODS

Nightly actigraphy estimates of sleep in 79 children and adolescents were measured throughout 4 weeks post-concussion. Total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), number of arousals (NOA), and average arousal length (AAL) were measured.

RESULTS

Child and adolescent participants experienced significantly poorer SE and longer WASO duration throughout 4 weeks of recovery and adolescents experienced significantly longer TST. SE significantly improved with time post-injury (p = .047). Older age was associated with longer TST (p = .003) and female sex was associated with longer WASO (p = .025) and AAL duration (p = .044). Week 4 sleep parameter outcomes were not significantly different between asymptomatic and symptomatic participants.

CONCLUSIONS

The sleep quality of youth is adversely affected by concussion, particularly in females. Sleep quality appears to improve with time but may require more than 4 weeks to return to normal.

Trajectories of Insomnia in Adults After Traumatic Brain Injury

IMPORTANCE

Insomnia is common after traumatic brain injury (TBI) and contributes to morbidity and long-term sequelae.

OBJECTIVE

To identify unique trajectories of insomnia in the 12 months after TBI.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective cohort study, latent class mixed models (LCMMs) were used to model insomnia trajectories over time and to classify participants into distinct profile groups. Data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, a longitudinal, multisite, observational study, were uploaded to the Federal Interagency Traumatic Brain Injury Repository (FITBIR) database. Participants were enrolled at 1 of 18 participating level I trauma centers and enrolled within 24 hours of TBI injury. Additional data were obtained directly from the TRACK-TBI investigators that will be uploaded to FITBIR in the future. Data were collected from February 26, 2014, to August 8, 2018, and analyzed from July 1, 2020, to November 15, 2021.

EXPOSURES

Traumatic brain injury.

MAIN OUTCOMES AND MEASURES

Insomnia Severity Index assessed serially at 2 weeks and 3, 6, and 12 months thereafter.

RESULTS

The final sample included 2022 participants (1377 [68.1%] men; mean [SD] age, 40.1 [17.2] years) from the FITBIR database and the TRACK-TBI study. The data were best fit by a 5-class LCMM. Of these participants, 1245 (61.6%) reported persistent mild insomnia symptoms (class 1); 627 (31.0%) initially reported mild insomnia symptoms that resolved over time (class 2); 91 (4.5%) reported persistent severe insomnia symptoms (class 3); 44 (2.2%) initially reported severe insomnia symptoms that resolved by 12 months (class 4); and 15 (0.7%) initially reported no insomnia symptoms but had severe symptoms by 12 months (class 5). In a multinomial logistic regression model, several factors significantly associated with insomnia trajectory class membership were identified, including female sex (odds ratio [OR], 1.65 [95% CI, 1.02-2.66]), Black race (OR, 2.36 [95% CI, 1.39-4.01]), history of psychiatric illness (OR, 2.21 [95% CI, 1.35-3.60]), and findings consistent with intracranial injury on computed tomography (OR, 0.36 [95% CI, 0.20-0.65]) when comparing class 3 with class 1.

CONCLUSIONS AND RELEVANCE

These results suggest important heterogeneity in the course of insomnia after TBI in adults. More work is needed to identify outcomes associated with these insomnia trajectory class subgroups and to identify optimal subgroup-specific treatment approaches.

Neurological Symptoms and Their Associations With Inflammatory Biomarkers in the Chronic Phase Following Traumatic Brain Injuries

BACKGROUND

The underlying biological mechanisms for neurological symptoms following a traumatic brain injury (TBI) remain poorly understood. This study investigated the associations between serum inflammatory biomarkers and neurological symptoms in the chronic phase following moderate to severe TBI.

METHODS

The serum interleukin [IL]-1β, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, and the tumor necrosis factor [TNF]-α in 72 TBI patients 6 months to 2 years post injury were measured. Neurological symptoms including depression, chronic headache, sleep disturbance, irritability, anxiety, and global neurological disability was assessed. The associations between the biomarkers and the neurological symptoms were assessed using correlation and regression analysis.

RESULTS

It was found that the most common post-injury symptom was sleep disturbance (84.7%), followed by chronic headaches (59.7%), irritability (55.6%), and depression (54.2%). TNF-α was a protective factor for chronic headache (OR = 0.473, 95% CI = 0.235-0.952). IL-6 was positively associated with sleep disturbance (r = 0.274, p = 0.021), while IL-5 and IL-12p70 were negatively associated with the degree of global neurological disability (r = -0.325, p = 0.006; r = -0.319, p = 0.007).

CONCLUSION

This study provides preliminary evidence for the association between chronic inflammation with neurological symptoms following a TBI, which suggests that anti-inflammatory could be a potential target for post-TBI neurological rehabilitation. Further research with larger sample sizes and more related biomarkers are still needed, however, to elucidate the inflammatory mechanisms for this association.

Prevalence of insomnia and insomnia symptoms following mild-traumatic brain injury: A systematic review and meta-analysis

Sleep is commonly disrupted following mild traumatic brain injury (mTBI), however there is a lack of consensus in the existing literature regarding the prevalence of insomnia/insomnia symptoms after injury. The aim of this review was to conduct a systematic review and meta-analysis of insomnia and insomnia symptoms' prevalence following mTBI. Full-text articles published in English in peer-reviewed journals, including adults with a clinical or self-reported mild traumatic brain injury diagnosis, were eligible for inclusion. Studies that assessed insomnia/insomnia symptoms after injury were included. Of the 2091 records identified, 20 studies were included in the review. 19 of these were meta-analysed (n = 95,195), indicating high heterogeneity among studies. Subgroup analyses indicated pooled prevalence estimates of post-mTBI insomnia disorder of 27.0% (95% CI 6.49-54.68) and insomnia symptoms of 71.7% (95% CI 60.31-81.85). The prevalence of insomnia is significantly higher in individuals who have sustained mild traumatic brain injury compared to prevalence estimates reported in the general population but high heterogeneity and methodological differences among studies make it difficult to provide reliable prevalence estimates. Future research should continue to advance our understanding of the onset, progression and impact of post-mild traumatic brain injury insomnia to promote the recovery and wellbeing of affected individuals. PROSPERO registration CRD42020168563.

Influence of Sleep Dysfunction on Concussion Assessment Outcomes Among Adolescent Athletes After Concussion and Healthy Controls

BACKGROUND

Sleep dysfunction (SD) is associated with a high symptom burden and lower neurocognitive performance after concussion and on baseline testing without injury. However, few studies have compared concussed athletes and controls with and without SD on clinical outcomes.

OBJECTIVE

To evaluate differences in clinical outcomes among both concussed athletes and matched controls with and without SD.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

Participants aged 12 to 20 years were recruited from a concussion clinic (n = 50 patients) and research registry/flyers (n = 50 healthy age-/sex-matched controls). Participants were categorized by self-reported SD into one of 4 groups: sport-related concussion (SRC) + SD, SRC only, SD only, and controls.

MAIN OUTCOME MEASURES

Post-Concussion Symptom Scale (PCSS), Vestibular/Oculomotor Screening (VOMS), and neurocognitive testing (Immediate Postconcussion Assessment Cognitive Test).

RESULTS

Compared with the SRC only group, the SRC + SD group performed worse on all neurocognitive domains, had a higher total symptom score, and endorsed more symptoms on most VOMS items. In addition, the SRC + SD group was at an increased likelihood of having at least 1 abnormal VOMS item compared with SRC only group. The SRC only group had neurocognitive test scores and symptom reports statistically similar to the SD only group.

CONCLUSION

Sleep dysfunction after concussion is related to worse neurocognitive performance and higher concussion symptom reporting. This study extended findings to suggest vestibular symptomology is worse among athletes with SD after injury compared to injured athletes without SD. Similar performances on concussion assessments for the SRC only and SD only groups suggest SD may appear similar to clinical presentation of concussion, even at baseline in the absence of SRC.

Gaze stability in young adults with previous concussion history

BACKGROUND

Disruption of visual-vestibular interaction after concussion can cause gaze instability with head movements. The long-term impact of concussion on gaze stability is unknown.

OBJECTIVE

This cross-sectional comparative pilot study examined gaze stability in the chronic stage after concussion (greater than one year). A secondary objective was to examine the relationship between gaze stability and sleep.

METHODS

Outcome measures included: 1. Gaze stability in logMAR (mean loss of dynamic visual acuity (DVA) in the yaw and pitch planes); 2. Pittsburgh Sleep Quality Index (PSQI); 3. Epworth Sleepiness Scale (ESS). Post-Concussion Symptom Scale (PCSS), time since injury, and number of concussions were collected for the people with concussion.

RESULTS

The study sample included thirty-four adults (mean age 23.35±1.3 years). Seventeen had a history of 1-9 concussions, with a mean duration of 4.4±1.9 years since last concussion; and 17 were age and sex-matched controls. Mean pitch plane DVA loss was greater in the concussion group compared to the control group (p = 0.04). Participants with previous concussion had lower sleep quality based on the PSQI (p = 0.01) and increased daytime sleepiness based on the ESS (p = 0.01) compared to healthy controls. Mean DVA loss in the pitch plane was significantly correlated with the PSQI (r = 0.43, p = 0.01) and the ESS (r = 0.41, p = 0.02).

CONCLUSION

Significant differences in dynamic visual acuity may be found in young adults long after a concussion, compared with those who have no concussion history. Furthermore, loss of dynamic visual acuity was associated with poorer sleep quality and higher daytime sleepiness.

Sport-Specific Increased Risk of Anterior Cruciate Ligament Injury Following a Concussion in Collegiate Female Lacrosse

ABSTRACT

Poor neurocognitive performance has been associated with a greater risk of musculoskeletal injury, and anterior cruciate ligament (ACL) injury prevention protocols include exercises to improve neuromuscular control. Research shows that a concussion elevates the risk for subsequent lower-extremity injury, because concussions lead to lower neurocognitive performance. Studies have been conducted using data within individual male sports, such as football and rugby, or across collegiate sports in aggregate; no study has focused on women's sports. Using 7 years of data collected by athletic training staff at Davidson College, this paper evaluates preconcussive versus postconcussive lower-extremity injury risk across five collegiate women's sports: field hockey, soccer, basketball, volleyball, and lacrosse. Using incidence rate ratios, lacrosse athletes had a five-fold increase in ACL injury risk within 365 d following a concussion. Recognizing that postconcussive ACL tear risk varies across different women's sports is important in informing sport-specific concussion return to play protocols.

Link between Mild Traumatic Brain Injury, Poor Sleep, and Magnetic Resonance Imaging: Visible Perivascular Spaces in Veterans

Impaired clearance of perivascular waste in the brain may play a critical role in morbidity after mild traumatic brain injury (mTBI). We aimed to determine the effect of mTBI on the burden of magnetic resonance imaging (MRI)-visible perivascular spaces (PVSs) in a cohort of U.S. military veterans and whether sleep modulates this effect. We also investigated the correlation between PVS burden and severity of persistent post-concussive symptoms. Fifty-six Iraq/Afghanistan veterans received 3 Tesla MRI as part of a prospective cohort study on military blast mTBI. White matter PVS burden (i.e., number and volume) was calculated using an established automated segmentation algorithm. Multi-variate regression was used to establish the association between mTBIs sustained in the military and PVS burden. Covariates included age, blood pressure, number of impact mTBIs outside the military, and blast exposures. Correlation coefficients were calculated between PVS burden and severity of persistent post-concussive symptoms. There was a significant positive relationship between the number of mTBIs sustained in the military and both PVS number and volume (p = 0.04). A significant interaction was found between mTBI and poor sleep on PVS volume (p = 0.04). A correlation was found between PVS number and volume, as well as severity of postconcussive symptoms (p = 0.03). Further analysis revealed a moderate correlation between PVS number and volume, as well as balance problems (p < 0.001). In Iraq/Afghanistan veterans, mTBI is associated with an increase in PVS burden. Further, an interaction exists between mTBI and poor sleep on PVS burden. Increased PVS burden, which may indicate waste clearance dysfunction, is associated with persistent post-concussive symptom severity.

Sleep Measure Validation in a Pediatric Neurocritical Care Acquired Brain Injury Population

BACKGROUND/OBJECTIVE

Lingering morbidities including physical, cognitive, emotional, and psychosocial sequelae, termed the Post-Intensive Care Syndrome, persist years after pediatric neurocritical care (PNCC) hospitalization. Sleep disturbances impact other Post-Intensive Care Syndrome domains and are under-evaluated to date due to a lack of appropriate measurement tools. The present study evaluated the validity of the Sleep Disturbance Scale for Children (SDSC) to address the growing need for assessing sleep problems after PNCC.

METHODS

We conducted a prospective observational study of youth aged 3-17 years with acquired brain injury (N = 69) receiving care through longitudinal PNCC programs at two tertiary academic medical centers. Parents completed the SDSC and provided proxy reports of internalizing symptoms, health-related quality of life (HRQOL), fatigue, pain behavior, and cognitive function within 3 months of hospital discharge. Evidence for the validity of the SDSC was established by utilizing the full sample for psychosocial measure comparisons and by comparing SDSC outcomes by severity (Low Risk, Mild-Moderate Risk, and High Risk defined by reported standardized T-scores).

RESULTS

Internal consistency of the SDSC was good (α = .81). Within the full sample, increased sleep disturbances on the SDSC were significantly correlated with Post-Intensive Care Syndrome measures, including worse physical (r = .65), psychological (r = .62), and cognitive (r = - .74) sequelae. Youth in the High Risk group evidenced greater dysfunction in mental acuity, pain behavior, internalizing symptoms, and social engagement. Findings revealed both statistically and clinically significant impacts of sleep disturbances as measured by the SDSC on HRQOL.

CONCLUSIONS

The SDSC is a valid and reliable measure for assessing sleep disturbances in children after PNCC. Results support the use of the SDSC to measure sleep disturbances after PNCC. Targeted interventions for sleep disturbances may be key to overall patient recovery.

Oculomotor Deficits and Symptom Severity Are Associated With Poorer Dynamic Mobility in Chronic Mild Traumatic Brain Injury

Oculomotor deficits, vestibular impairments, and persistent symptoms are common after a mild traumatic brain injury (mTBI); however, the relationship between visual-vestibular deficits, symptom severity, and dynamic mobility tasks is unclear. Twenty-three individuals (mean age 55.7 ± 9.3 years) with persistent symptoms after mTBI, who were between 3 months to 2 years post-injury were compared with 23 age and sex-matched controls. Oculomotor deficits [depth perception, near-point convergence, baseline visual acuity (BLVA), perception time], vestibular deficits (dynamic visual acuity in the pitch and yaw planes), dynamic mobility measured by the Functional Gait Assessment (FGA), and symptoms measured by the Post-Concussion Symptom Scale (PCSS) and Dizziness Handicap Inventory (DHI) were compared between groups. Participants with mTBI had poorer performance on the FGA (p < 0.001), higher symptom severity on the PCSS (p < 0.001), and higher DHI scores (p < 0.001) compared to controls. Significant differences were seen on specific items of the FGA between individuals with mTBI and controls during walking with horizontal head turns (p = 0.002), walking with vertical head tilts (p < 0.001), walking with eyes closed (p = 0.003), and stair climbing (p = 0.001). FGA performance was correlated with weeks since concussion (r = −0.67, p < 0.001), depth perception (r = −0.5348, p < 0.001), near point convergence (r = −0.4717, p = 0.001), baseline visual acuity (r = −0.4435, p = 0.002); as well as with symptoms on the PCSS (r = −0.668, p < 0.001), and DHI (r = −0.811, p < 0.001). Dynamic balance deficits persist in chronic mTBI and may be addressed using multifaceted rehabilitation strategies to address oculomotor dysfunction, post-concussion symptoms, and perception of handicap due to dizziness.

Sex-based differences in outcomes for adult patients presenting to the emergency department with a concussion

OBJECTIVE

Patients with concussion frequently present to the emergency department (ED). Studies of athletes and children indicate that concussion symptoms are often more severe and prolonged in females compared with males. Given infrequent study of concussion symptoms in the general adult population, the authors conducted a sex-based comparison of patients with concussion.

METHODS

Adults (≥ 17 years of age) presenting with concussion to one of three urban Canadian EDs were recruited. Discharged patients were contacted by telephone 30 and 90 days later to capture the extent of persistent postconcussion symptoms using the Rivermead Post Concussion Symptoms Questionnaire (RPQ). A multivariate logistic regression model for persistent symptoms that included biological sex was developed.

RESULTS

Overall, 250 patients were included; 131 (52%) were women, and the median age of women was significantly higher than that of men (40 vs 32 years). Women had higher RPQ scores at baseline (p < 0.001) and the 30-day follow-up (p = 0.001); this difference resolved by 90 days. The multivariate logistic regression identified that women, patients having a history of sleep disorder, and those presenting to the ED with concussions after a motor vehicle collision were more likely to experience persistent symptoms.

CONCLUSIONS

In a community concussion sample, inconsequential demographic differences existed between adult women and men on ED presentation. Based on self-reported and objective outcomes, work and daily activities may be more affected by concussion and persistent postconcussion symptoms for women than men. Further analysis of these differences is required to identify different treatment options and ensure adequate care and management of injury.

Distant histories of mild traumatic brain injury exacerbate age-related differences in white matter properties

We examined associations of distant histories of mild traumatic brain injury (mTBI) with non-linear and linear trajectories of white matter (WM) properties across a wide age range (23-77). Diffusion tensor imaging (DTI) data obtained from 171 Veterans with histories of clinically diagnosed mTBIs and 115 controls were subjected to tractography, isolating 20 major WM tracts. Non-linear and linear effects of age on each tract's diffusion properties were examined in terms of their interactions with group (mTBI and control). The non-linear model revealed 7 tracts in which the mTBI group's DTI metrics rapidly deviated from control trajectories in middle and late adulthoods, despite the injuries having occurred in the late 20s, on average. In contrast, no interactions between prior injuries and age were detected when examining linear trajectories. Distant mTBIs may thus accelerate normal age-related trajectories of WM degeneration much later in life. As such, life-long histories of head trauma should be assessed in all patients in their mid-to-late adulthoods, whether neurologically healthy or presenting with seemingly unrelated neuropathology.

The impact of exercise, sleep, and diet on neurocognitive recovery from mild traumatic brain injury in older adults: A narrative review

Mild traumatic brain injury (mTBI) accounts for a large majority of traumatic brain injuries sustained globally each year. Older adults, who are already susceptible to age-related declines to neurocognitive health, appear to be at an increased risk of both sustaining an mTBI and experiencing slower or impaired recovery. There is also growing evidence that mTBI is a potential risk factor for accelerated cognitive decline and neurodegeneration. Lifestyle-based interventions are gaining prominence as a cost-effective means of maintaining cognition and brain health with age. Consequently, inter-individual variations in exercise, sleep, and dietary patterns could influence the trajectory of post-mTBI neurocognitive recovery, particularly in older adults. This review synthesises the current animal and human literature centred on the mechanisms through which lifestyle-related habits and behaviours could influence acute and longer-term neurocognitive functioning following mTBI. Numerous neuroprotective processes which are impacted by lifestyle factors have been established in animal models of TBI. However, the literature is characterised by a lack of translation to human samples and limited appraisal of the interaction between ageing and brain injury. Further research is needed to better establish the therapeutic utility of applying lifestyle-based modifications to improve post-mTBI neurocognitive outcomes in older adults.

Sleep quality in the chronic stage of concussion is associated with poorer recovery: A systematic review

Background

Recovery from a concussion varies based on a multitude of factors. One such factor is sleep disturbances. In our prior review, it was observed that in the acute phase, sleep disturbances are predictive of poor outcomes following a concussion. The literature gap remains on how sleep in the chronic phase of recovery affects outcomes.

Objective

To examine the association between sleep quality during the chronic stage of concussion and post-concussion outcomes. Literature Survey: Literature searches were performed during 1 July to 1 August 2019 in selected databases along with searching grey literature. Out of the 733 results, 702 references were reviewed after duplicate removal.

Methods

Three reviewers independently reviewed and consented on abstracts meeting eligibility criteria ( n = 35). The full-text articles were assessed independently by two reviewers. Consensus was achieved, leaving four articles. Relevant data from each study was extracted using a standard data-extraction table. Quality appraisal was conducted to assess potential bias and the quality of articles.

Results

One study included children (18–60 months) and three studies included adolescents and/or adults (ranging 12–35 years). The association between sleep and cognition (two studies), physical activity (one study), and emotion symptoms (one study) was examined. Sleep quality was associated with decreased cognition and emotional symptoms, but not with meeting physical activity guidelines six months post-concussion injury.

Conclusions

The heterogeneity in age of participants and outcomes across studies and limited number of included studies made interpretations difficult. Future studies may consider if addressing sleep quality following concussion will improve outcomes.

Sleep in Neurologic Disorders

Sleep is a complex brain state with fundamental relevance for cognitive functions, synaptic plasticity, brain resilience, and autonomic balance. Sleep pathologies may interfere with cerebral circuit organization, leading to negative consequences and favoring the development of neurologic disorders. Conversely, the latter can interfere with sleep functions. Accordingly, assessment of sleep quality is always recommended in the diagnosis of patients with neurologic disorders and during neurorehabilitation programs. This review investigates the complex interplay between sleep and brain pathologies, focusing on diseases in which the association with sleep disturbances is commonly overlooked and whereby major benefits may derive from their proper management.

Blue-Light Therapy Strengthens Resting-State Effective Connectivity within Default-Mode Network after Mild TBI

Background:

Emerging evidence suggests that post concussive symptoms, including mood changes, may be improved through morning blue-wavelength light therapy (BLT). However, the neurobiological mechanisms underlying these effects remain unknown. We hypothesize that BLT may influence the effective brain connectivity (EC) patterns within the default-mode network (DMN), particularly involving the medial prefrontal cortex (MPFC), which may contribute to improvements in mood.

Methods:

Resting-state functional MRI data were collected from 41 healthy-controls (HCs) and 28 individuals with mild traumatic brain injury (mTBI). Individuals with mTBI also underwent a diffusion-weighted imaging scan and were randomly assigned to complete either 6 weeks of daily morning BLT (N = 14) or amber light therapy (ALT; N = 14). Advanced spectral dynamic causal modeling (sDCM) and diffusion MRI connectometry were used to estimate EC patterns and structural connectivity strength within the DMN, respectively.

Results:

The sDCM analysis showed dominant connectivity pattern following mTBI (pre-treatment) within the hemisphere contralateral to the one observed for HCs. BLT, but not ALT, resulted in improved directional information flow (ie, EC) from the left lateral parietal cortex (LLPC) to MPFC within the DMN. The improvement in EC from LLPC to MPFC was accompanied by stronger structural connectivity between the 2 areas. For the BLT group, the observed improvements in function and structure were correlated (at a trend level) with changes in self-reported happiness.

Conclusions:

The current preliminary findings provide empirical evidence that morning short-wavelength light therapy could be used as a novel alternative rehabilitation technique for mTBI.

Trial registry:

The research protocols were registered in the ClinicalTrials.gov database (CT Identifiers NCT01747811 and NCT01721356).

Patient Attribution of Posttraumatic Symptoms to Brain Injury Versus PTSD in Military-Related Mild TBI

OBJECTIVE

Persistent cognitive, somatic, and neuropsychiatric symptoms following mild traumatic brain injury (TBI) are influenced by posttraumatic stress disorder (PTSD), particularly in military patients. The authors evaluated the degree to which military service members with a history of mild TBI attributed posttraumatic symptoms to TBI versus PTSD.

METHODS

Service members (N=372) with mild TBI were surveyed about the severity of posttraumatic symptoms across four symptom clusters (cognitive, affective, somatosensory, and vestibular) with the Neurobehavioral Symptom Inventory (NSI). Participants rated the degree to which they believed TBI, PTSD, or other conditions contributed to their symptoms. Differences in cognitive, affective, somatosensory, and vestibular symptom severity were evaluated across participants with TBI, PTSD, or combined TBI-PTSD attribution. Logistic regression was used to evaluate the association between symptom profiles and attribution.

RESULTS

Participants attributed symptoms mostly to TBI, followed by insufficient sleep, PTSD, chronic pain, depression, and deployment-readjustment stress. PTSD and combined TBI-PTSD attribution were associated with higher total NSI scores (39.5 and 51.6, respectively), compared with TBI attribution only (31.4) (F=29.08, df=3, 358, p<0.01), as well as higher scores in every symptom category. More severe affective symptoms were associated with decreased odds of TBI attribution (odds ratio=0.90, 95% CI=0.83-0.97) and increased odds of PTSD attribution (odds ratio=1.14, 95% CI=1.03-1.26). A PTSD diagnosis was highly associated with PTSD attribution (odds ratio=2.44, 95% CI=1.07-5.58).

CONCLUSIONS

The nature and severity of posttraumatic symptoms appear to play a role in patient beliefs about the causes of symptoms, whether from TBI or PTSD.

The relationship between accelerometer-measured sleep and next day ecological momentary assessment symptom report during sport-related concussion recovery

OBJECTIVES

Research examining sleep and concussion symptoms following sport-related concussion (SRC) is limited by retrospective self-report rather than objective data from wearable technology and real-time symptom report. The purpose of this study is to use actigraphy and ecological momentary assessment (EMA) to examine the relationship between sleep parameters and next day symptoms.

METHODS

Seventeen athletes (47.1%F) aged 12-19 (15.35+/-2.09) years (<72 hours post-SRC) wore Actigraph GT3x+ to measure nighttime sleep and completed post-concussion symptom scales (PCSS) three times via mobile EMA, resulting in a range of 91-177 observations for each outcome. Generalized linear mixed models, utilizing independent variables of sleep efficiency (SE%: ratio of awake time to sleep time) and total sleep time (TST) examined the associations between nightly sleep and symptoms next-day and throughout recovery.

RESULTS

SE% (IRR .97, 95%CI: .95, .99, P= .009) and TST (IRR .91, 95%CI: .84, .999, P = .047) were negatively associated with next day night symptoms. The negative relationship between SE% and the cognitive-migraine-fatigue (CMF) factor was significant for next day/night symptoms (P = .01), while TST was associated with symptom severity for the affective symptom factor (P = .015). Sleep was negatively associated with total symptoms and afternoon symptoms in Week 1 and total, morning, afternoon, and night symptoms in Week 2 (ps=.001-.021) of recovery.

CONCLUSION

Sleep was negatively associated with symptoms the next day, especially late in the day and among CMF and emotional symptoms. The relationship between sleep and symptom burden was strongest in the subacute stage of concussion recovery, highlighting the potential importance of sleep intervention post-injury.

Sleep after Traumatic Brain Injury

Sleep disturbances are common after traumatic brain injury of all levels of severity, interfere with acute and long-term recovery, and can persist for years after injury. There is increasing evidence of the importance of sleep in improving brain function and recovery. Noticing and addressing sleep disturbances are important aspects of nursing care, especially for the prevention or early recognition of delirium. Nonpharmacologic interventions can improve sleep. Teaching about the importance of sleep after traumatic brain injury, promoting sleep hygiene, and multidisciplinary approaches to addressing sleep problems and improving sleep are important for recovery from traumatic brain injury.

Relationship between Sport-Related Concussion and Sleep Based on Self-Report and Commercial Actigraph Measurement

Sleep-wake disturbance (SWD) results from sport-related concussion (SRC) and may increase risk of protracted post-injury symptoms. However, methodological limitations in the extant literature limit our understanding of the role of SWD in SRC. This study examined the association between acute/subacute SRC and two sleep behaviors—sleep duration and efficiency—as measured by self-report and commercially available actigraphy (CA) in a sample of football players enrolled in a larger prospective longitudinal study of concussion. Fifty-seven high school and Division 3 male football players with SRC (mean [M] age = 18.00 years, standard deviation [SD] = 1.44) and 26 male teammate controls (M age = 18.54 years, SD = 2.21) were enrolled in this prospective pilot study. Sleep duration and sleep efficiency were recorded nightly for 2 weeks (starting 24–48 h post-injury in the SRC group) via CA and survey delivered via mobile application. There was no significant relationship between SRC and objectively recorded sleep measures, a null finding. However, the SRC group reported a brief (3-day) reduction in sleep efficiency after injury (M SRC = 82.18, SD = 12.24; M control = 89.2, SD = 4.25; p = 0.013; Cohen's d = 0.77), with no change in sleep duration. Self-reported and actigraph-assessed hours of sleep were weakly and insignificantly correlated in the SRC group (r = −0.21, p = 0.145), whereas they were robustly correlated in the non-injured control group (r = 0.65, p = 0.004). SWD post-SRC was not observed in objectively measured sleep duration or sleep efficiency and was modest and time-limited based on self-reported sleep efficiency. The weak correlation between self-reported and objective sleep behavior measures implies that subjective experience of SWD post-SRC may be due to factors other than actual changes in these observable sleep behaviors. Clinically, SWD in the early-subacute stages of recovery from SRC may not be adequately measurable via current CA. Subjective SWD may require alternative methods of evaluation (e.g., clinical actigraph or sleep study).

Preliminary Validation of the Sleep and Concussion Questionnaire as an Outcome Measure for Sleep Following Brain Injury

BACKGROUND

Sleep and wakefulness disturbances are common with traumatic brain injury (TBI); however, there are no condition-specific measures to evaluate sleep following TBI.

OBJECTIVE

To assess the convergent validity of the Sleep and Concussion Questionnaire (SCQ), a condition-specific (TBI) measure is compared to polysomnography and existing self-report sleep questionnaires.

PARTICIPANTS INCLUDED

Thirty-two adults diagnosed with mild TBI, 3-24 months post-injury, average age, 38.9 years, predominantly female (63%) and with symptoms of chronic insomnia.

METHODS

Participants underwent polysomnographic evaluation of sleep and completed the SCQ, Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), and the Fatigue Severity Scale (FSS). Correlations were assessed using Pearson's correlations. The sample was sufficiently powered (0.85) to detect a moderate to strong correlation of 0.5 or greater.

RESULTS

SCQ sub-questions were meaningfully correlated with corresponding objective sleep parameters (time awake, number of awakenings, sleep efficiency, sleep onset latency, wake after sleep onset) as measured with polysomnography. Additional significant correlations were seen between total scores on the SCQ and ISI and between SCQ sub questions and total ESS scores.

CONCLUSIONS

This work provides initial evidence of the convergent validity of the SCQ with objective sleep parameters and existing self-report measures in patients after mild TBI.

Concussion and Risk of Chronic Medical and Behavioral Health Comorbidities

While chronic neurological effects from concussion have been studied widely, little is known about possible links between concussion and long-term medical and behavioral comorbidities. We performed a retrospective cohort study of 9205 adult patients with concussion, matched to non-concussion controls from a hospital-based electronic medical registry. Patients with comorbidities before the index visit were excluded. Behavioral and medical comorbidities were defined by International Classification of Diseases, Ninth and Tenth Revision codes. Groups were followed for up to 10 years to identify comorbidity incidence after a concussion. Cox proportional hazards models were used to calculate associations between concussion and comorbidities after multi-variable adjustment. Patients with concussion were 57% male (median age: 31; interquartile range [IQR] = 23-48 years) at enrollment with a median follow-up time of 6.1 years (IQR = 4.2-9.1) and well-matched to healthy controls. Most (83%) concussions were evaluated in outpatient settings (5% inpatient). During follow-up, we found significantly higher risks of cardiovascular risks developing including hypertension (hazard ratio [HR] = 1.7, 95% confidence interval [CI]: 1.5-1.9), obesity (HR = 1.7, 95% CI: 1.3-2.0), and diabetes mellitus (HR = 1.8, 95% CI: 1.4-2.3) in the concussion group compared with controls. Similarly, psychiatric and neurological disorders such as depression (HR = 3.0, 95% CI: 2.6-3.5), psychosis (HR = 6.0, 95% CI: 4.2-8.6), stroke (HR = 2.1 95% CI: 1.5-2.9), and epilepsy (HR = 4.4, 95% CI: 3.2-5.9) were higher in the concussion group. Most comorbidities developed less than five years post-concussion. The risks for post-concussion comorbidities were also higher in patients under 40 years old compared with controls. Patients with concussion demonstrated an increased risk of development of medical and behavioral health comorbidities. Prospective studies are warranted to better describe the burden of long-term comorbidities in patients with concussion.

The Prevalence and Stability of Sleep-Wake Disturbance and Fatigue throughout the First Year after Mild Traumatic Brain Injury

In this prospective, longitudinal study, we aimed to determine the prevalence and stability of sleep-wake disturbance (SWD) and fatigue in a large representative sample of patients (Trondheim mild traumatic brain injury [mTBI] follow-up study). We included 378 patients with mTBI (age 16-60), 82 matched trauma controls with orthopedic injuries, and 83 matched community controls. Increased sleep need, poor sleep quality, excessive daytime sleepiness, and fatigue were assessed at 2 weeks, 3 months, and 12 months after injury. Mixed logistic regression models were used to evaluate clinically relevant group differences longitudinally. Prevalence of increased sleep need, poor sleep quality, and fatigue was significantly higher in patients with mTBI than in both trauma controls and community controls at all time points. More patients with mTBI reported problems with excessive daytime sleepiness compared to trauma controls, but not community controls, at all time points. Patients with complicated mTBI (intracranial findings on computed tomography or magnetic resonance imaging) had more fatigue problems compared to those with uncomplicated mTBI, at all three time points. In patients with mTBI who experienced SWDs and fatigue 2 weeks after injury, around half still had problems at 3 months and approximately one third at 12 months. Interestingly, we observed limited overlap between the different symptom measures; a large number of patients reported one specific problem with SWD or fatigue rather than several problems. In conclusion, our results provide strong evidence that mTBI contributes significantly to the development and maintenance of SWDs and fatigue.

Healthcare Utilization Following Traumatic Brain Injury in a Large National Sample

OBJECTIVE

To evaluate the impact of traumatic brain injury (TBI) on healthcare utilization (HCU) over a 1-year period in a large national sample of individuals diagnosed with TBI across multiple care settings.

SETTING

Commercial insurance enrollees.

PARTICIPANTS

Individuals with and without TBI, 2008-2014.

DESIGN

Retrospective cohort.

MAIN MEASURES

We compared the change in the 12-month sum of inpatient, outpatient, emergency department (ED), and prescription HCU from pre-TBI to post-TBI to the same change among a non-TBI control group. Most rehabilitation visits were not included. We stratified models by age ≥65 and included the month of TBI in subanalysis.

RESULTS

There were 207 354 individuals in the TBI cohort and 414 708 individuals in the non-TBI cohort. Excluding the month of TBI diagnosis, TBI resulted in a slight increase in outpatient visits (rate ratio [RtR] = 1.05; 95% confidence interval [CI], 1.04-1.06) but decrease in inpatient HCU (RtR = 0.86; 95% CI, 0.84-0.88). Including the month of TBI in the models resulted in increased inpatient (RtR = 1.55; 95% CI, 1.52-1.58) and ED HCU (RtR = 1.37; 95% CI, 1.34-1.40).

CONCLUSION

In this population of individuals who maintained insurance coverage following TBI, results suggest that TBI may have a limited impact on nonrehabilitation HCU at the population level.

Bypassing TBI: Metabolic Surgery and the Link between Obesity and Traumatic Brain Injury-a Review

Obesity is a common outcome of traumatic brain injury (TBI) that exacerbates principal TBI symptom domains identified as common areas of post-TBI long-term dysfunction. Obesity is also associated with increased risk of later-life dementia and Alzheimer's disease. Patients with obesity and chronic TBI may be more vulnerable to long-term mental abnormalities. This review explores the question of whether weight loss induced by bariatric surgery could delay or perhaps even reverse the progression of mental deterioration. Bariatric surgery, with its induction of weight loss, remission of type 2 diabetes, and other expressions of the metabolic syndrome, improves metabolic efficiency, leads to reversal of brain lesions seen on imaging studies, and improves function. These observations suggest that metabolic/bariatric surgery may be a most effective therapy for TBI.