Characterizing self-reported sleep disturbance after mild traumatic brain injury

Increased Risk for Clinically Significant Sleep Disturbances in Mild Traumatic Brain Injury: An Approach to Leveraging the Federal Interagency Traumatic Brain Injury Research Database

STUDY OBJECTIVES

The Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System contains individual-patient-level traumatic brain injury (TBI) data, which when combined, allows for the examination of rates and outcomes for key subpopulations at risk for developing sleep disturbance.

METHODS

This proof-of-concept study creates a model system for harmonizing data (i.e., combining and standardizing data) across FITBIR studies for participants with and without a history of TBI to estimate rates of sleep disturbance and identify risk factors.

RESULTS

Three studies were eligible for harmonization (N = 1753). Sleep disturbance was common among those with a history of mild TBI (63%). Individuals with mild TBI were two to four times more likely to have sleep disturbance compared to those with no history of TBI.

CONCLUSIONS

This study established methods, harmonization code, and meta-databases that are publicly available on the FITBIR website. We demonstrated how the harmonization of FITBIR studies can answer TBI research questions, showing that associations between TBI and sleep disturbance may be influenced by demographic factors.

Traumatic brain injury and sleep in military and veteran populations: A literature review

BACKGROUND

Traumatic brain injury (TBI) is a hallmark of wartime injury and is related to numerous sleep wake disorders (SWD), which persist long term in veterans. Current knowledge gaps in pathophysiology have hindered advances in diagnosis and treatment.

OBJECTIVE

We reviewed TBI SWD pathophysiology, comorbidities, diagnosis and treatment that have emerged over the past two decades.

METHODS

We conducted a literature review of English language publications evaluating sleep disorders (obstructive sleep apnea, insomnia, hypersomnia, parasomnias, restless legs syndrome and periodic limb movement disorder) and TBI published since 2000. We excluded studies that were not specifically evaluating TBI populations.

RESULTS

Highlighted areas of interest and knowledge gaps were identified in TBI pathophysiology and mechanisms of sleep disruption, a comparison of TBI SWD and post-traumatic stress disorder SWD. The role of TBI and glymphatic biomarkers and management strategies for TBI SWD will also be discussed.

CONCLUSION

Our understanding of the pathophysiologic underpinnings of TBI and sleep health, particularly at the basic science level, is limited. Developing an understanding of biomarkers, neuroimaging, and mixed-methods research in comorbid TBI SWD holds the greatest promise to advance our ability to diagnose and monitor response to therapy in this vulnerable population.

Multifaceted neural and vascular pathologies after pediatric mild traumatic brain injury

Dynamic changes in neurodevelopment and cognitive functioning occur during adolescence, including a switch from reactive to more proactive forms of cognitive control, including response inhibition. Pediatric mild traumatic brain injury (pmTBI) affects these cognitions immediately post-injury, but the role of vascular versus neural injury in cognitive dysfunction remains debated. This study consecutively recruited 214 sub-acute pmTBI (8-18 years) and age/sex-matched healthy controls (HC; N = 186), with high retention rates (>80%) at four months post-injury. Multimodal imaging (functional MRI during response inhibition, cerebral blood flow and cerebrovascular reactivity) assessed for pathologies within the neurovascular unit. Patients exhibited increased errors of commission and hypoactivation of motor circuitry during processing of probes. Evidence of increased/delayed cerebrovascular reactivity within motor circuitry during hypercapnia was present along with normal perfusion. Neither age-at-injury nor post-concussive symptom load were strongly associated with imaging abnormalities. Collectively, mild cognitive impairments and clinical symptoms may continue up to four months post-injury. Prolonged dysfunction within the neurovascular unit was observed during proactive response inhibition, with preliminary evidence that neural and pure vascular trauma are statistically independent. These findings suggest pmTBI is characterized by multifaceted pathologies during the sub-acute injury stage that persist several months post-injury.

The Correlation of Sleep Disturbance and Location of Glioma Tumors: A Narrative Review

Sleep disturbance can occur when sleep centers of the brain, regions that are responsible for coordinating and generating healthy amounts of sleep, are disrupted by glioma growth or surgical resection. Several disorders cause disruptions to the average duration, quality, or patterns of sleep, resulting in sleep disturbance. It is unknown whether specific sleep disorders can be reliably correlated with glioma growth, but there are sufficient numbers of case reports to suggest that a connection is possible. In this manuscript, these case reports and retrospective chart reviews are considered in the context of the current primary literature on sleep disturbance and glioma diagnosis to identify a new and useful connection which warrants further systematic and scientific examination in preclinical animal models. Confirmation of the relationship between disruption of the sleep centers in the brain and glioma location could have significant implications for diagnostics, treatment, monitoring of metastasis/recurrence, and end-of-life considerations.

Functional Outcomes, Injury Variables, and Athlete Characteristics Associated with Post-Concussion Sleep Disturbance

OBJECTIVE

To examine the relationship between sleep disturbance and functional outcomes following a concussion. Also, to explore athlete and injury-related variables that may be related to risk factors for poor sleep following concussion.

METHOD

124 collegiate athletes completed a neuropsychological evaluation within 14 days of sustaining a sport-related concussion (SRC). Athletes were categorized as sleep disturbed (n = 52) or not sleep disturbed (n = 72). Outcome variables included symptom reports, cognitive performance (mean performance and variability), and mood (depression). Injury characteristics and athlete characteristics explored were loss of consciousness (LOC) associated with the injury, whether the athlete was immediately removed from play, and history of prior concussions.

RESULTS

Sleep disturbed athletes reported more symptoms, F(4, 119) = 7.82, p < 0.001, ƞ2 = 0.21, were more likely to be symptomatic at the time of testing, χ2(1, N = 124) = 19.79, p < 0.001, φ = 0.40, and were marginally more likely to experience clinically significant depression, χ2(1, N = 120) = 3.03, p = 0.08, φ = 0.16, than not sleep disturbed athletes. There were no cognitive differences between the groups, p > 0.05. A greater proportion of sleep disturbed athletes experienced LOC (30%) compared to not sleep disturbed athletes (13%), χ2(1, N = 118) = 4.99, p = 0.03, φ = -0.21.

CONCLUSION

Sleep disturbances following SRC are associated with a broad range of self-reported symptoms. LOC may be associated with an increased risk of developing sleep disturbances; alternatively, sleep disturbances may increase the risk of LOC following concussion.

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.

Sleep and the Young Athlete

CONTEXT

Sleep plays a vital role in cognitive and physical performance. Teenage athletes (ages 13-19 years) are considered especially at risk for disordered sleep and associated negative cognitive, physical, and psychosomatic effects. However, there is a paucity of evidence-based recommendations to promote sleep quality and quantity in athletes who fall within this age range. We performed a review of the literature to reveal evidence-based findings and recommendations to help sports instructors, athletic trainers, physical therapists, physicians, and other team members caring for young athletes provide guidance on sleep optimization for peak sports performance and injury risk reduction.

METHODS

PubMed, Scopus, and Cochrane CENTRAL were searched on May 11, 2016, and then again on September 1, 2020, for relevant articles published to date.

STUDY DESIGN

Narrative review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Few studies exist on the effects disordered sleep may have on teenage athletes. By optimizing sleep patterns in young athletes during training and competitions, physical and mental performance, and overall well-being, may be optimized. Adequate sleep has been shown to improve the performance of athletes, although further studies are needed.

CONCLUSION

Twenty-five percent of total sleep time should be deep sleep, with a recommended sleep time of 8 to 9 hours for most young athletes. Screen and television use during athletes' bedtime should be minimized to improve sleep quality and quantity. For young athletes who travel, jet lag can be minimized by allowing 1 day per time zone crossed for adjustment, limiting caffeine intake, planning meals and onboard sleeping to coincide with destination schedules, timing arrivals in the morning whenever possible, and using noise-canceling headphones and eyeshades.

STRENGTH-OF-RECOMMENDATION TAXONOMY (SORT)

B.

Behavioral and Cognitive Aspects of Concussion

PURPOSE OF REVIEW

This review provides the reader with an overview of concussion and mild traumatic brain injury (TBI). Key aspects of the pathophysiology, signs, and symptoms, treatment and rehabilitation, and recovery from concussion/mild TBI are reviewed with an emphasis on the variety of factors that may contribute to cognitive concerns following injury.

RECENT FINDINGS

Concussion remains a clinical diagnosis based on symptoms that occur in the immediate aftermath of an applied force and in the hours, days, and weeks thereafter. Although advances have been made in advanced diagnostics, including neuroimaging and fluid biomarkers in hopes of developing objective indicators of injury, such markers currently lack sufficient specificity to be used in clinical diagnostics. The symptoms of concussion are heterogeneous and may be seen to form subtypes, each of which suggests a targeted rehabilitation by the interdisciplinary team. Although the majority of patients with concussion recover within the first 30 to 90 days after injury, some have persistent disabling symptoms. The concept of postconcussion syndrome, implying a chronic syndrome of injury-specific symptoms, is replaced by a broader concept of persistent symptoms after concussion. This concept emphasizes the fact that most persistent symptoms have their basis in complex somatic, cognitive, psychiatric, and psychosocial factors related to risk and resilience. This framework leads to the important conclusion that concussion is a treatable injury from which nearly all patients can be expected to recover.

SUMMARY

Concussion/mild TBI is a significant public health problem in civilian, military, and organized athletic settings. Recent advances have led to a better understanding of underlying pathophysiology and symptom presentation and efficacious treatment and rehabilitation of the resulting symptoms. An interdisciplinary team is well-positioned to provide problem-oriented, integrated care to facilitate recovery and to advance the evidence base supporting effective practice in diagnosis, treatment, and prevention.

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.

Can Adults Recognize Concussion Symptoms? A Critical Review of Empirical Research Using the Rosenbaum Concussion Knowledge and Attitudes Survey

OBJECTIVE

The correct identification of concussion symptoms is vital for mild traumatic brain injury recognition, diagnosis, and injury management. Numerous surveys of symptom recognition have been conducted, including with athletes at-risk for injury. This critical, methodologically focused review aimed to: (1) discover which concussion symptoms are recognized, and (2) provide recommendations for future research.

DATA SOURCES

A quasi-systematic literature search was conducted to identify studies that used the Rosenbaum Concussion Knowledge and Attitudes Survey.

STUDY SELECTION

Eighty-five publications were identified, 8 of which were retained after screening.

DATA EXTRACTION

The identification of individual concussion symptoms was coded as good (a correct response by >90% of the sample), moderate (a correct response by 75%-90% of the sample), or poor (a correct response by <75% of the sample).

DATA SYNTHESIS

The pooled data comprised responses from more than 2000 individuals, most of whom were male, young adult, sport players. Overall, there was good recognition of 3 concussion symptoms (headaches, dizziness, and confusion), poor recognition of sleep disturbances, nausea, and loss of consciousness, and misattribution to concussion of 2 distractor symptoms (weakness of neck range of motion, difficulty speaking). The methodological evaluation revealed significant variability in symptom measurement.

CONCLUSIONS

The identified trends for concussion symptom recognition must be regarded as tentative because of the significant methodological variation in the reviewed studies. This variability affected the number, wording, and classification of items, and it restricted the data synthesis. This problem must be addressed in future research and recommendations are provided.

Cellular Senescence in Traumatic Brain Injury: Evidence and Perspectives

Mild traumatic brain injury (mTBI) can lead to long-term neurological dysfunction and increase one's risk of neurodegenerative disease. Several repercussions of mTBI have been identified and well-studied, including neuroinflammation, gliosis, microgliosis, excitotoxicity, and proteinopathy – however the pathophysiological mechanisms activating these pathways after mTBI remains controversial and unclear. Emerging research suggests DNA damage-induced cellular senescence as a possible driver of mTBI-related sequalae. Cellular senescence is a state of chronic cell-cycle arrest and inflammation associated with physiological aging, mood disorders, dementia, and various neurodegenerative pathologies. This narrative review evaluates the existing studies which identify DNA damage or cellular senescence after TBI (including mild, moderate, and severe TBI) in both experimental animal models and human studies, and outlines how cellular senescence may functionally explain both the molecular and clinical manifestations of TBI. Studies on this subject clearly show accumulation of various forms of DNA damage (including oxidative damage, single-strand breaks, and double-strand breaks) and senescent cells after TBI, and indicate that cellular senescence may be an early event after TBI. Further studies are required to understand the role of sex, cell-type specific mechanisms, and temporal patterns, as senescence may be a pathway of interest to target for therapeutic purposes including prognosis and treatment.

Sleep disturbances following traumatic brain injury are associated with poor neurobehavioral outcomes in U.S. military service members and veterans

STUDY OBJECTIVES

This study examined whether sleep disturbances were associated with neurobehavioral outcome following a traumatic brain injury (TBI) in a well characterized group of service members and veterans.

METHODS

Six-hundred and six participants were enrolled into the Defense and Veterans Brain Injury Center, 15-Year Longitudinal TBI study. All participants completed a battery of tests measuring self-reported sleep disturbances, neurobehavioral symptoms, and Posttraumatic Stress Disorder PTSD symptoms. Data were analyzed using analysis of variance with post-hoc comparisons. Four groups were analyzed separately: uncomplicated mild TBI (MTBI); complicated mild, moderate, severe, or penetrating - combined TBI (CTBI); injured controls (IC, i.e., orthopedic or soft-tissue injury without TBI); and non-injured controls (NIC).

RESULTS

A higher proportion of the MTBI group reported moderate-severe sleep disturbances (66.5%) compared to the IC (54.9%), CTBI (47.5%), and NIC groups (34.3%). Participants classified as having Poor Sleep had significantly worse scores on the majority of TBI-QOL scales compared to those classified as having Good Sleep, regardless of TBI severity or the presence of TBI. There was a significant interaction between sleep disturbances and PTSD. While sleep disturbances and PTSD by themselves were significant factors associated with worse outcome, both factors combined resulted in worse outcome than either singularly.

CONCLUSIONS

Regardless of group (injured or NIC), sleep disturbances were common and were associated with significantly worse neurobehavioral functioning. When experienced concurrently with PTSD, sleep disturbances pose significant burden to service members and veterans.

Multipotential and systemic effects of traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of disability and mortality of people at all ages. Biochemical, cellular and physiological events that occur during primary injury lead to a delayed and long-term secondary damage that can last from hours to years. Secondary brain injury causes tissue damage in the central nervous system and a subsequent strong and rapid inflammatory response that may lead to persistent inflammation. However, this inflammatory response is not limited to the brain. Inflammatory mediators are transferred from damaged brain tissue to the bloodstream and produce a systemic inflammatory response in peripheral organs, including the cardiovascular, pulmonary, gastrointestinal, renal and endocrine systems. Complications of TBI are associated with its multiple and systemic effects that should be considered in the treatment of TBI patients. Therefore, in this review, an attempt was made to examine the systemic effects of TBI in detail. It is hoped that this review will identify the mechanisms of injury and complications of TBI, and open a window for promising treatment in TBI complications.

Traumatic Brain Injury and Incidence Risk of Sleep Disorders in Nearly 200,000 US Veterans

OBJECTIVE

To test the hypothesis that veterans with traumatic brain injury (TBI) have an increased subsequent risk of sleep disorders, we studied the longitudinal association between TBI and incident sleep disorders in nearly 200,000 veterans.

METHODS

We performed a cohort study of all patients diagnosed with a TBI in the Veterans Health Administration system from October 1, 2001, to September 30, 2015, who were age-matched 1:1 to veterans without TBI. Veterans with prevalent sleep disorders at baseline were excluded. Development of sleep disorders was defined as any inpatient or outpatient diagnosis of sleep apnea, hypersomnia, insomnia, or sleep-related movement disorders based on ICD-9 codes after the first TBI diagnosis or the random selection date for those without TBI. We restricted the analysis to those with at least 1 year of follow-up. We used Cox proportional hazards models to examine the association between TBI and subsequent risk of sleep disorders.

RESULTS

The study included 98,709 veterans with TBI and 98,709 age-matched veterans without TBI (age 49 ± 20 years). After an average follow-up of 5 (1-14) years, 23,127 (19.6%) veterans developed sleep disorders. After adjustment for demographics, education, income, and medical and psychiatric conditions, those who had TBI compared to those without TBI were 41% more likely to develop any sleep disorders (hazard ratio 1.41 [95% confidence interval 1.37-1.44]), including sleep apnea (1.28 [1.24-1.32]), insomnia (1.50 [1.45-1.55]), hypersomnia (1.50 [1.39-1.61]), and sleep-related movement disorders (1.33 [1.16-1.52]). The association was stronger for mild TBIs, did not differ appreciably by presence of posttraumatic stress disorder, and remained after a 2-year time lag.

CONCLUSION

In 197,418 veterans without sleep disorders, those with diagnosed TBI had an increased risk of incident sleep disorders over 14 years. Improved prevention and long-term management strategies for sleep are needed for veterans with TBI.

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.

Persistent alterations in cerebrovascular reactivity in response to hypercapnia following pediatric mild traumatic brain injury

Much attention has been paid to the effects of mild traumatic brain injury (mTBI) on cerebrovascular reactivity in adult populations, yet it remains understudied in pediatric injury. In this study, 30 adolescents (12-18 years old) with pediatric mTBI (pmTBI) and 35 age- and sex-matched healthy controls (HC) underwent clinical and neuroimaging assessments during sub-acute (6.9 ± 2.2 days) and early chronic (120.4 ± 11.7 days) phases of injury. Relative to controls, pmTBI reported greater initial post-concussion symptoms, headache, pain, and anxiety, resolving by four months post-injury. Patients reported increased sleep issues and exhibited deficits in processing speed and attention across both visits. In grey-white matter interface areas throughout the brain, pmTBI displayed increased maximal fit/amplitude of a time-shifted end-tidal CO2 regressor to blood oxygen-level dependent response relative to HC, as well as increased latency to maximal fit. The alterations persisted through the early chronic phase of injury, with maximal fit being associated with complaints of ongoing sleep disturbances during post hoc analyses but not cognitive measures of processing speed or attention. Collectively, these findings suggest that deficits in the speed and degree of cerebrovascular reactivity may persist longer than current conceptualizations about clinical recovery within 30 days.

An observational study of the association between sleep disturbance, fatigue and cognition in the post-acute period after mild traumatic brain injury in prospectively studied premorbidly healthy adults

The literature examining the relationship between sleep disturbance, fatigue, and cognition in premorbidly healthy civilian adults after mTBI is very limited. The current study aimed to investigate the relationships of sleep disturbance and fatigue with cognition while controlling for psychological distress and age. Using a prospective observational design, we assessed 60 premorbidly healthy individuals approximately 8 weeks after mTBI. Participants were assessed with the Pittsburgh Sleep Quality Index and the Multidimensional Fatigue Inventory as well as measures of speed of information processing, attention, memory, and executive function; depression and anxiety were also assessed. Findings revealed associations between sleep disturbance and cognition (r²= .586, p < .001) as well as between fatigue and cognition (r²= .390, p < .01), independent of the impact of psychological status and age. Associations were evident in the domains of processing speed, attention, and memory, but were most consistently apparent on measures of executive function. Greater sleep disturbance was most consistently associated with poorer cognitive function. Unexpectedly, higher levels of fatigue were associated with better cognitive function, which may be explained by the coping hypothesis. Given sleep interventions have been shown to improve sleep disturbance, these findings suggest that sleep intervention may also result in improved cognition after mTBI.

Long-Term Impact of Mild Traumatic Brain Injuries on Multiple Functional Outcomes and Epigenetics: A Pilot Study with College Students

People who suffer a mild traumatic brain injury (mTBI) have heterogeneous symptoms and disease trajectories, which make it difficult to precisely assess long-term complications. This pilot study assessed and compared deficits in cognitive, psychosocial, visual functions, and balance performance between college students with and without histories of mTBI. Global DNA methylation ratio (5-mC%) in blood was also compared as a peripheral epigenetic marker. Twenty-five volunteers participated, including 14 healthy controls (64.3% females; mean age of 22.0) and 11 mTBI cases (27.3% females; mean age of 28.7 years) who self-reported mTBI history (63.6% multiple; 2.5 ± 1.29 injuries) with 7.1 years on average elapsed following the last injury. Every participant was assessed for cognitive (executive function, memory, and processing speed), psychological (depression, anxiety, and sleep disturbances), and visual function (by King–Devick and binocular accommodative tests); force-plate postural balance performance; and blood 5-mC% levels. Students with mTBI showed poorer episodic memory, severe anxiety, and higher blood 5-mC% ratio, compared to controls (all p’s < 0.05), which were still significant after adjusting for age. No differences were detected in sleep problems (after adjusting for age), visual function, and postural balance. These findings identified changes in multiple functions and peripheral epigenetics long after mTBI.

Sleep Disturbances in the Acute Stage of Concussion are Associated With Poorer Long-Term Recovery: A Systematic Review

OBJECTIVE

To examine the association between sleep during the acute stage of concussion and long-term outcomes.

LITERATURE SURVEY

Literature searches were performed 1 July 2018 to 1 August 2018 in Ovid MEDLINE, CINAHL, and Web of Science, along with hand searching for gray literature and cited references. Of the 610 search results, 359 unique references were reviewed after duplicates were removed.

METHODOLOGY

Two reviewers independently reviewed and came to consensus on which titles/abstracts met inclusion/exclusion criteria (n = 23). The 23 full-text articles were assessed independently by the same two reviewers for eligibility. Consensus was achieved, leaving four articles for quality assessment and data extraction. One person extracted relevant data from each study using a standard data-extraction table. The data extraction table was reviewed by two reviewers and consensus was achieved for completeness and accuracy. Quality appraisal was conducted to assess the risk for potential bias and quality of included articles.

SYNTHESIS

Two of the articles included children younger than 16 years old and two included a wide age range. In general, poorer sleep was associated with poorer outcomes following concussion at reassessments across any age population. In addition, poorer sleep in the acute stage of concussion was associated with poorer long-term outcomes and recovery.

CONCLUSIONS

The variability in sleep assessments used, symptoms assessed, length of time to reassessments, and comparator group included made data synthesis challenging. The use of standard valid and reliable sleep assessments is recommended. Future studies may consider if addressing sleep disturbances early following concussion will improve longer-term outcomes.

Relationships between Post-Concussion Sleep and Symptom Recovery: A Preliminary Study

Post-concussion sleep disturbances can be debilitating and may influence days to symptom recovery; however, evidence is minimal. The purpose of this study was to explore relationships between days to symptom recovery and aspects of sleep, as measured by actigraphy and subjective sleep questionnaires in a concussed sample. Thirty-one college students were physician-diagnosed with a concussion and asked to complete a daily sleep symptom checklist. Participants (n = 14) were excluded based on lack of compliance/early termination (22.6%), recorded <5 nights of data (12.9%), and protracted recoveries (3.2%). Final concussed sample included 17 college-aged students (varsity student-athletes, n = 5; university students, n = 12). A wrist-worn ActiGraph GT9X Link was provided during initial evaluation (within 72 h post-injury) and worn continuously until symptom recovery (follow-up evaluation; 14.3 ± 5.9 days post-injury). The Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) also were completed at follow-up. Pearson's correlations were conducted to determine relationships between days to symptom recovery and actigraphy sleep outcomes (sleep onset latency, wake after sleep onset (WASO_norm), total sleep time, sleep efficiency (SE), and number of awakenings) across recovery stages (2-3 days post-injury, mid-point, and end). Spearman's rho correlations were used to determine relationships between subjective sleep (PSQI global), sleepiness (ESS total), and sleep cluster symptom severity and days to symptom recovery. At recovery mid-point, individuals who were awake longer throughout the night (24.1 ± 9.0%) and/or were less efficient at sleeping (73.7 ± 9.7%) took longer to recover (WASO_norm: r = 0.58, p = 0.015; SE: r = -0.51, p = 0.035). Poorer post-concussion sleep quality (based on PSQI) was correlated with longer recovery (r_s = 0.70, p = 0.001). Post-concussion sleep-wake disturbances at recovery mid-point and overall poorer sleep quality may be associated with longer symptom recovery. Our findings provide preliminary guidance on identifying those who may be at risk for longer recoveries based on poorer sleep post-injury.

Proactive inhibition deficits with normal perfusion after pediatric mild traumatic brain injury

Although much attention has been generated in popular media regarding the deleterious effects of pediatric mild traumatic brain injury (pmTBI), a paucity of empirical evidence exists regarding the natural course of biological recovery. Fifty pmTBI patients (12-18 years old) were consecutively recruited from Emergency Departments and seen approximately 1 week and 4 months post-injury in this prospective cohort study. Data from 53 sex- and age-matched healthy controls (HC) were also collected. Functional magnetic resonance imaging was obtained during proactive response inhibition and at rest, in conjunction with independent measures of resting cerebral blood flow. High temporal resolution imaging enabled separate modeling of neural responses for preparation and execution of proactive response inhibition. A priori predictions of failed inhibitory responses (i.e., hyperactivation) were observed in motor circuitry (pmTBI>HC) and sensory areas sub-acutely and at 4 months post-injury. Paradoxically, pmTBI demonstrated hypoactivation (HC>pmTBI) during target processing, along with decreased activation within prefrontal cognitive control areas. Functional connectivity within motor circuitry at rest suggested that deficits were limited to engagement during the inhibitory task, whereas normal resting cerebral perfusion ruled out deficits in basal perfusion. In conclusion, current results suggest blood oxygen-level dependent deficits during inhibitory control may exceed commonly held beliefs about physiological recovery following pmTBI, potentially lasting up to 4 months post-injury.

Concussion - Part I: The need for a multifaceted assessment

INTRODUCTION

Concussion is among the most commonly occurring sport and recreation injuries in today's society. An understanding of the heterogenous nature of concussion will assist in directing a multifaceted and comprehensive interdisciplinary assessment following injury.

PURPOSE

The purpose of this masterclass article is to summarize the current state of the evidence in the area of concussion, describe typical symptom presentations and assessment techniques that may assist in directing appropriate management following concussion.

IMPLICATIONS

A comprehensive assessment including a thoughtful differential diagnosis will assist the clinician to direct care appropriately and efficiently in individuals who have suffered a concussion.

Impact of traumatic brain injury on sleep: an overview

Traumatic brain injury (TBI) is a global health problem that affects millions of civilians, athletes, and military personnel yearly. Sleeping disorders are one of the underrecognized sequalae even though they affect 46% of individuals with TBI. After a mild TBI, 29% of patients have insomnia, 25% have sleep apnea, 28% have hypersomnia, and 4% have narcolepsy. The type of sleep disturbance may also vary according to the number of TBIs sustained. Diffuse axonal injury within the sleep regulation system, disruption of hormones involved in sleep, and insults to the hypothalamus, brain stem, and reticular activating system are some of the proposed theories for the pathophysiology of sleep disorders after TBI. Genetic and anatomical factors also come to play in the development and severity of these sleeping disorders. Untreated sleep disturbances following TBI can lead to serious consequences with respect to an individual's cognitive functioning. Initial management focuses on conservative measures with progression to more aggressive options if necessary. Future research should attempt to establish the effectiveness of the treatments currently used, as well as identify manageable co-existing factors that could be exacerbating sleep disorders.

Potential for the development of light therapies in mild traumatic brain injury

Light affects almost all aspects of human physiological functioning, including circadian rhythms, sleep-wake regulation, alertness, cognition and mood. We review the existing relevant literature on the effects of various wavelengths of light on these major domains, particularly as they pertain to recovery from mild traumatic brain injuries. Evidence suggests that light, particularly in the blue wavelengths, has powerful alerting, cognitive and circadian phase shifting properties that could be useful for treatment. Other wavelengths, such as red and green may also have important effects that, if targeted appropriately, might also be useful for facilitating recovery. Despite the known effects of light, more research is needed. We recommend a personalized medicine approach to the use of light therapy as an adjunctive treatment for patients recovering from mild traumatic brain injury.

Sleep, Sleep Disorders, and Circadian Health following Mild Traumatic Brain Injury in Adults: Review and Research Agenda

A rapidly expanding scientific literature supports the frequent co-occurrence of sleep and circadian disturbances following mild traumatic brain injury (mTBI). Although many questions remain unanswered, the preponderance of evidence suggests that sleep and circadian disorders can result from mTBI. Among those with mTBI, sleep disturbances and clinical sleep and circadian disorders contribute to the morbidity and long-term sequelae across domains of functional outcomes and quality of life. Specifically, along with deterioration of neurocognitive performance, insufficient and disturbed sleep can precede, exacerbate, or perpetuate many of the other common sequelae of mTBI, including depression, post-traumatic stress disorder, and chronic pain. Further, sleep and mTBI share neurophysiologic and neuroanatomic mechanisms that likely bear directly on success of rehabilitation following mTBI. For these reasons, focus on disturbed sleep as a modifiable treatment target has high likelihood of improving outcomes in mTBI. Here, we review relevant literature and present a research agenda to 1) advance understanding of the reciprocal relationships between sleep and circadian factors and mTBI sequelae and 2) advance rapidly the development of sleep-related treatments in this population.

Heading and unintentional head impacts have opposing associations with Patient Reported Outcomes in amateur soccer players

The effects of soccer-related head impacts, beyond overt concussions, on Patient Reported Outcomes (PROs) have not been explored to date. Generalized estimating equations were employed to determine the association between soccer-related head impacts (headers in the prior 2 weeks, unintentional head impacts in the prior 2 weeks, headers in the prior 12 months and lifetime concussions) on PROs including depression, anxiety, sleep disturbance and sleep impairment. Compared to players with no unintentional head impacts in the prior 2 weeks, players with one unintentional exposure reported more symptoms of anxiety (p = 0.002) and players with 2+ exposures reported more symptoms of depression (p = 0.006) and anxiety (p < 0.001). In contrast, players in the 3rd Quartile of 12 mo. headers reported less anxiety (p = 0.001), sleep disturbance (p = 0.002) and sleep impairment (p < 0.001) compared to those in the 1st quartile. Unintentional head impacts are associated with worse PROs while more headers are paradoxically associated with better PROs.

Efficacy of melatonin with behavioural sleep-wake scheduling for delayed sleep-wake phase disorder: A double-blind, randomised clinical trial

BACKGROUND

Delayed Sleep-Wake Phase Disorder (DSWPD) is characterised by sleep initiation insomnia when attempting sleep at conventional times and difficulty waking at the required time for daytime commitments. Although there are published therapeutic guidelines for the administration of melatonin for DSWPD, to our knowledge, randomised controlled trials are lacking. This trial tested the efficacy of 0.5 mg melatonin, combined with behavioural sleep-wake scheduling, for improving sleep initiation in clinically diagnosed DSWPD patients with a delayed endogenous melatonin rhythm relative to patient-desired (or -required) bedtime (DBT).

METHODS

This randomised, placebo-controlled, double-blind clinical trial was conducted in an Australian outpatient DSWPD population. Following 1-wk baseline, clinically diagnosed DSWPD patients with delayed melatonin rhythm relative to DBT (salivary dim light melatonin onset [DLMO] after or within 30 min before DBT) were randomised to 4-wk treatment with 0.5 mg fast-release melatonin or placebo 1 h before DBT for at least 5 consecutive nights per week. All patients received behavioural sleep-wake scheduling, consisting of bedtime scheduled at DBT. The primary outcome was actigraphic sleep onset time. Secondary outcomes were sleep efficiency in the first third of time in bed (SE T1) on treatment nights, subjective sleep-related daytime impairment (Patient Reported Outcomes Measurement Information System [PROMIS]), PROMIS sleep disturbance, measures of daytime sleepiness, clinician-rated change in illness severity, and DLMO time.

FINDINGS

Between September 13, 2012 and September 1, 2014, 307 participants were registered; 116 were randomised to treatment (intention-to-treat n = 116; n = 62 males; mean age, 29.0 y). Relative to baseline and compared to placebo, sleep onset occurred 34 min earlier (95% confidence interval [CI] -60 to -8) in the melatonin group. SE T1 increased; PROMIS sleep-related impairment, PROMIS sleep disturbance, insomnia severity, and functional disability decreased; and a greater proportion of patients showed more than minimal clinician-rated improvement following melatonin treatment (52.8%) compared to placebo (24.0%) (P < 0.05). The groups did not differ in the number of nights treatment was taken per protocol. Post-treatment DLMO assessed in a subset of patients (n = 43) was not significantly different between groups. Adverse events included light-headedness, daytime sleepiness, and decreased libido, although rates were similar between treatment groups. The clinical benefits or safety of melatonin with long-term treatment were not assessed, and it remains unknown whether the same treatment regime would benefit patients experiencing DSWPD sleep symptomology without a delay in the endogenous melatonin rhythm.

CONCLUSIONS

In this study, melatonin treatment 1 h prior to DBT combined with behavioural sleep-wake scheduling was efficacious for improving objective and subjective measures of sleep disturbances and sleep-related impairments in DSWPD patients with delayed circadian phase relative to DBT. Improvements were achieved largely through the sleep-promoting effects of melatonin, combined with behavioural sleep-wake scheduling.

TRIAL REGISTRATION

This trial was registered with the Australian New Zealand Clinical Trials Registry, ACTRN12612000425897.

Actigraphically Measured Sleep-Wake Behavior After Mild Traumatic Brain Injury: A Case-Control Study

OBJECTIVE

To characterize and compare the sleep-wake behavior of individuals following a mild traumatic brain injury (mTBI) with that of noninjured healthy controls.

SETTING

Community.

PARTICIPANTS

Fourteen participants with a recent mTBI (Mage = 28.07; SD = 10.45; n = 10 females) and 34 noninjured controls (Mage = 23.70; SD = 7.30; n = 31 females).

DESIGN

Cross-sectional.

MAIN MEASURES

Battery of subjective sleep measures and 14 days of sleep-wake monitoring via actigraphy (objective measurement) and concurrent daily sleep diary.

RESULTS

Participants who had sustained an mTBI self-reported significantly higher sleep-related impairment, poorer nightly sleep quality, and more frequently met criteria for clinical insomnia, compared with controls (d = 0.76-1.11, large effects). The only significant between-group difference on objective sleep metrics occurred on sleep timing. On average, people with a recent history of mTBI fell asleep and woke approximately 1 hour earlier than did the controls (d = 0.62-0.92, medium to large effects).

CONCLUSION

Participants with a history of mTBI had several subjective sleep complaints but relatively few objective sleep changes with the exception of earlier sleep timing. Future research is needed to understand the clinical significance of these findings and how these symptoms can be alleviated. Interventions addressing subjective sleep complaints (eg, cognitive behavior therapy for insomnia) should be tested in this population.

Blue-Light Therapy following Mild Traumatic Brain Injury: Effects on White Matter Water Diffusion in the Brain

Mild traumatic brain injury (mTBI) is a common and often inconspicuous wound that is frequently associated with chronic low-grade symptoms and cognitive dysfunction. Previous evidence suggests that daily blue wavelength light therapy may be effective at reducing fatigue and improving sleep in patients recovering from mTBI. However, the effects of light therapy on recovering brain structure remain unexplored. In this study, we analyzed white matter diffusion properties, including generalized fractional anisotropy, and the quantity of water diffusion in isotropic (i.e., isotropic diffusion) and anisotropic fashion (i.e., quantitative anisotropy, QA) for fibers crossing 11 brain areas known to be significantly affected following mTBI. Specifically, we investigated how 6 weeks of daily morning blue light exposure therapy (compared to an amber-light placebo condition) impacted changes in white matter diffusion in individuals with mTBI. We observed a significant impact of the blue light treatment (relative to the placebo) on the amount of water diffusion (QA) for multiple brain areas, including the corpus callosum, anterior corona radiata, and thalamus. Moreover, many of these changes were associated with improvements in sleep latency and delayed memory. These findings suggest that blue wavelength light exposure may serve as one of the potential non-pharmacological treatments for facilitating structural and functional recovery following mTBI; they also support the use of QA as a reliable neuro-biomarker for mTBI therapies.

A COMPREHENSIVE INSTRUMENT FOR EVALUATING MILD TRAUMATIC BRAIN INJURY (MTBI)/CONCUSSION IN INDEPENDENT ADULTS: A PILOT STUDY

BACKGROUND

One common component of concussion rehabilitation is a computerized cognitive test free of concomitant physical demands. Healthcare professionals may be able to provide more patient-centered care after a diagnosed concussion if specific areas of impairment are identified and treated, such as the physical aspect of neurocognitive function. Hypothesis/Purpose: To evaluate the test-retest reliability of a unique combination of neurocognitive assessment tools currently utilized in concussion assessments into one single, inclusive instrument that measures both neurocognitive function and physical capability.

STUDY DESIGN

Original research - diagnostic tests.

METHODS

Fourteen individuals (nine males, age: 29 + 17.9, five females, age: 46.0 ± 21.5 years) either with normal cognitive function (NBI) without history of a health event (e.g. cerebral vascular accident/stroke, mTBI) that resulted in brain injury within one year of the study, or who had suffered a health event that has resulted in a medically documented brain injury (BI) participated in the study. Participants completed the full hybrid assessment instrument for a baseline test, then completed a follow-up test using the same instrument within 72-96 hours of baseline. Test-retest reliability was measured using Pearson product-moment correlations of the first and second testing sessions, and a two-way ANOVA (group between factor: NBI and BI and time within factor: session 1 and session 2) was performed on the summative scores to determine differences between each group.

RESULTS

Test-retest reliability was strong and statistical significant for both the NBI (r = .858, p = .014) and the BI (r = .967, p = .033) groups. There was a significant difference between summative scores for the NBI and BI groups (F_1,20 = 42.325, p < .0001).

CONCLUSION

The newly created Comprehensive Instrument for Evaluating Mild Traumatic Brain Injury (CIEMTBI) demonstrates good test-retest reliability and was able to discriminate the results between individuals in the NBI and BI groups. Further research, specifically with different samples, is needed to better determine the reliability and diagnostic accuracy of the instrument.

LEVEL OF EVIDENCE

2c.

Poor sleep quality and nightmares are associated with non-suicidal self-injury in adolescents

Non-suicidal self-injury (NSSI) is prevalent and is associated with increased risk of suicidal behavior in adolescents. This study examined which sleep variables are associated with NSSI, independently from demographics and mental health problems in Chinese adolescents. Participants consisted of 2090 students sampled from three high schools in Shandong, China and had a mean age of 15.49 years. Participants completed a sleep and health questionnaire to report their demographic and family information, sleep duration and sleep problems, impulsiveness, hopelessness, internalizing and externalizing problems, and NSSI. A series of regression analyses were conducted to examine the associations between sleep variables and NSSI. Of the sample, 12.6 % reported having ever engaged in NSSI and 8.8 % engaged during the last year. Univariate logistic analyses demonstrated that multiple sleep variables including short sleep duration, insomnia symptoms, poor sleep quality, sleep insufficiency, unrefreshed sleep, sleep dissatisfaction, daytime sleepiness, fatigue, snoring, and nightmares were associated with increased risk of NSSI. After adjusting for demographic and mental health variables, NSSI was significantly associated with sleeping <6 h per night, poor sleep quality, sleep dissatisfaction, daytime sleepiness, and frequent nightmares. Stepwise logistic regression model demonstrated that poor sleep quality (OR = 2.18, 95 % CI = 1.37-3.47) and frequent nightmares (OR = 2.88, 95 % CI = 1.45-5.70) were significantly independently associated with NSSI. In conclusion, while multiple sleep variables are associated with NSSI, poor sleep quality and frequent nightmares are independent risk factors of NSSI. These findings may have important implications for further research of sleep self-harm mechanisms and early detection and prevention of NSSI in adolescents.

Sleep Disturbances in Traumatic Brain Injury: A Meta-Analysis

STUDY OBJECTIVES

Sleep disturbances are frequently reported following traumatic brain injury (TBI); however, the exact disturbances remain unclear. This meta-analysis aimed to characterize sleep disturbance in community dwelling patients with TBI as compared to controls.

METHODS

Two investigators independently conducted a systematic search of multiple electronic databases from inception to May 27, 2015. Studies were selected if they compared sleep in community dwelling individuals with TBI relative to a control population without head injury. Data were pooled in meta-analysis with outcomes expressed as the standard mean difference (SMD) and 95% confidence interval (CI). The primary outcomes were derived from polysomnography and secondary outcomes were derived from subjective sleep measures.

RESULTS

Sixteen studies were included, combining 637 TBI patients and 567 controls, all of whom were community dwelling. Pooled polysomnography data revealed that TBI patients had poorer sleep efficiency (SMD = -0.47, CI: -0.89, -0.06), shorter total sleep duration (SMD = -0.37, CI: -0.59, -0.16), and greater wake after sleep onset time (SMD = 0.60, CI: 0.33, 0.87). Although sleep architecture was similar between the groups, a trend suggested that TBI patients may spend less time in REM sleep (SMD = -0.22, CI: -0.45, 0.01). Consistent with polysomnographic derangement, TBI patients reported greater subjective sleepiness and poorer perceived sleep quality.

CONCLUSIONS

The evidence suggests that TBI is associated with widespread objective and subjective sleep deficits. The present results highlight the need for physicians to monitor and address sleep deficits following TBI.

Post-concussion symptoms and chronic pain after mild traumatic brain injury are modulated by multiple locus effect in the BDNF gene through the expression of antisense: A pilot prospective control study

Background: Mild traumatic brain injury (mTBI) often results in post-concussion symptoms, chronic pain, and sleepiness. Genetic factors are thought to play an important role in poor prognosis.

Aims: The aims of this study are to (1) document the prevalence of pain and post-concussion symptoms in mTBI patients in acute and chronic phases (2) determine whether candidate genes predispose to post-concussive symptoms and pain.

Methods: Posttraumatic symptoms, evaluated using the Rivermead Post-Concussion Symptoms Questionnaire, and pain were assessed in 94 mTBI patients in the acute phase as well as in 22 healthy controls. Assessment was repeated in 36 patients after one year who agreed to participate in the follow-up visit. Gene polymorphisms and expression were assessed in mTBI patients and healthy controls.

Results: In the acute phase, mTBI patients with pain (69%) presented more psychological symptoms and sleepiness and were less able to return to work than those without pain. At one year, 19% of mTBI patients had persistent pain and psychological distress. Two haplotypes (H2 and H3) in the brain-derived neurotrophic factor (BDNF) gene were shown to be respectively deleterious and protective against post-concussion symptoms and pain in both acute and chronic phases. Protective haplotype H3 was associated with a decreased expression of the anti-sense of BDNF (BDNF-AS). Deleterious haplotype H2 predicted the development of chronic pain at one year, whereas H3 was protective.

Conclusions: This pilot study suggests a protective mechanism of a multilocus effect in BDNF, through BDNF-AS, against post-concussion symptoms and pain in the acute phase and possibly chronic pain at one year post-mTBI. The role of antisense RNA should be validated in larger cohorts.

Circadian Melatonin Rhythm Following Traumatic Brain Injury

BACKGROUND

Sleep-wake disturbances are highly prevalent following traumatic brain injury (TBI), impeding rehabilitaion and quality of life. However, the mechanisms underlying these sleep disturnbances are unclear, and efficacious treatments are lacking. To investigate possible mechanisms underlying sleep disturbance in TBI, we examined characteristics of the circadian rhythm of melatonin, a hormone involved in sleep-wake regulation. We compared TBI patients reporting sleep disturbance with age- and gender-matched healthy volunteers.

METHODS

We conducted an overnight observational study with salivary melatonin samples collected hourly in 9 patients with severe TBI and 9 controls. Salivary dim light melatonin onset (DLMO) as well as melatonin synthesis onset (SynOn) and offset (SynOff) were used to determine circadian timing. Total overnight salivary melatonin production was calculated as the area under the curve from melatonin synthesis onset to offset.

RESULTS

Compared with healthy individuals, TBI patients showed 42% less melatonin production overnight (d = 0.87; P = .034). The timing of DLMO was delayed by approximately 1.5 hours in patients with TBI compared with controls (d = 1.23; P = .003).

CONCLUSIONS

In patients with TBI, melatonin production was attenuated overnight, and the timing of melatonin secretion was delayed. We suggest that disruption to the circadian regulation of melatonin synthesis is a feature of severe TBI, possibly contributing to the sleep difficulties that are commonly reported in this population.

Greater neurobehavioral deficits occur in adult mice after repeated, as compared to single, mild traumatic brain injury (mTBI)

Mild traumatic brain injury (mTBI) accounts for the majority of all brain injuries and affected individuals typically experience some extent of cognitive and/or neuropsychiatric deficits. Given that repeated mTBIs often result in worsened prognosis, the cumulative effect of repeated mTBIs is an area of clinical concern and on-going pre-clinical research. Animal models are critical in elucidating the underlying mechanisms of single and repeated mTBI-associated deficits, but the neurobehavioral sequelae produced by these models have not been well characterized. Thus, we sought to evaluate the behavioral changes incurred after single and repeated mTBIs in mice utilizing a modified impact-acceleration model. Mice in the mTBI group received 1 impact while the repeated mTBI group received 3 impacts with an inter-injury interval of 24h. Classic behavior evaluations included the Morris water maze (MWM) to assess learning and memory, elevated plus maze (EPM) for anxiety, and forced swim test (FST) for depression/helplessness. Additionally, species-typical behaviors were evaluated with the marble-burying and nestlet shredding tests to determine motivation and apathy. Non-invasive vibration platforms were used to examine sleep patterns post-mTBI. We found that the repeated mTBI mice demonstrated deficits in MWM testing and poorer performance on species-typical behaviors. While neither single nor repeated mTBI affected behavior in the EPM or FST, sleep disturbances were observed after both single and repeated mTBI. Here, we conclude that behavioral alterations shown after repeated mTBI resemble several of the deficits or disturbances reported by patients, thus demonstrating the relevance of this murine model to study repeated mTBIs.

Neuroendocrine dysfunction and insomniain in mild traumatic brain injury patients

Mild traumatic brain injury (mTBI) has been a growing public health concern in the worldwide. To investigate the subjective and objective characteristics of insomnia following mTBI and the association between insomnia and hypothalamic-pituitary-adrenal (HPA) function of mTBI patients, 59 patients with mTBI (mTBI group) were compared with 50 healthy participants (control group) in the present study. The subjective and objective measures of insomnia were respectively obtained from Pittsburgh Sleep Quality (PSQI) and polysomnography (PSG). HPA function was measured with low-dose short synacthen test (LDSST). According to the comparative and correlation analysis of the two groups, for PSQI, the scores of sleep syndrome, sleep latency, sleep efficiency, overall sleep quality and daytime dysfunction of mTBI patients were all higher, however only sleep efficiency and daytime dysfunction of mTBI patients were related with peak cortisol on lDSST; while for PSG, sleep efficiency (SE) was lower and wake after sleep onset (WASO) was longer in mTBI patients, moreover SE and WASO of mTBI patients were correlated with peak cortisol on LDSTT; for HPA function indexes, only peak cortisol on LDSST was lower in mTBI patients. These findings suggested that mTBI patients experienced more serious subjective insomnia symptoms than objective measurement, which were associated with HPA dysfunction. This study may contribute to identifying better treatment for mTBI patients with insomnia.

Sleep difficulties one year following mild traumatic brain injury in a population-based study

BACKGROUND

Sleep quality affects all aspects of daily functioning, and it is vital for facilitating recovery from illness and injury. Sleep commonly becomes disrupted following moderate to severe brain injury, yet little is known about the prevalence of sleep disruption over time and how it impacts on recovery following mild injury.

METHODS

This was a longitudinal study of 346 adults who experienced a mild brain injury (aged ≥16 years) identified within a population-based incidence sample in New Zealand. The prevalence of sleep difficulties was assessed at baseline (within two weeks), one, six and 12 months, alongside other key outcomes.

RESULTS

One year post injury, 41.4% of people were identified as having clinically significant sleep difficulties, with 21.0% at a level indicative of insomnia. Poor sleep quality at baseline was significantly predictive of poorer post-concussion symptoms, mood, community integration, and cognitive ability one year post injury. The prevalence of insomnia following mild traumatic brain injury (TBI) was more than three times the rate found in the general population. Of those completing a sleep assessment at six and 12 months, 44.9% of the sample showed improvements in sleep quality, 16.2% remained stable, and 38.9% worsened.

CONCLUSIONS

Screening for sleep difficulties should occur routinely following a mild brain injury to identify adults potentially at risk of poor recovery. Interventions to improve sleep are needed to facilitate recovery from injury, and to prevent persistent sleep difficulties emerging.