Differences in sleep between concussed and nonconcussed college students: a matched case-control study

Concussion and the Sleeping Brain

BACKGROUND

Emerging research has suggested sleep to be a modifier of the trajectory of concussion recovery in adolescent and adult populations. Despite the growing recognition of the relationship between sleep and concussion, the mechanisms and physiological processes governing this association have yet to be established.

MAIN BODY

Following a concussion, a pathophysiologic cascade of events occurs, characterized by numerous factors including microglia activation, ionic imbalance, and release of excitatory neurotransmitters. Importantly, each of these factors plays a role in the regulation of the sleep-wake cycle. Therefore, dysregulation of sleep following injury may be a function of the diffuse disruption of cerebral functioning in the wake of both axonal damage and secondary physiological events. As the onset of sleep-related symptoms is highly variable following a concussion, clinicians should be aware of when and how these symptoms present. Post-injury changes in sleep have been reported in the acute, sub-acute, and chronic phases of recovery and can prolong symptom resolution, affect neurocognitive performance, and influence mood state. Though these changes support sleep as a modifier of recovery, limited guidance exists for clinicians or their patients in the management of sleep after concussion. This may be attributed to the fact that research has correlated sleep with concussion recovery but has failed to explain why the correlation exists. Sleep is a complex, multifactorial process and the changes seen in sleep that are seen following concussion are the result of interactions amongst numerous processes that regulate the sleep-wake cycle.

SHORT CONCLUSION

The assessment and management of sleep by identifying and considering the biological, sociological, and psychological interactions of this multifactorial process will allow for clinicians to address the dynamic nature of changes in sleep following concussion.

Influence of sleep symptoms on recovery from concussion in collegiate athletes: a LIMBIC MATARS consortium investigation

OBJECTIVE

Changes in sleep quality and quantity are commonly endorsed by individuals following a concussion. Limited data exists examining the role of sleep disturbances within 72 hours, and throughout recovery, from concussion. The objective of this study was to determine if the number of days to symptom resolution varied between collegiate athletes with or without sleep-related symptoms following a concussion.

DESIGN

Retrospective chart review.

METHODS

Collegiate athletes (n = 539) who were diagnosed with a concussion between the 2015-2020 sport seasons participated in this retrospective chart review. Participants were divided into groups based on the presence or absence of sleep symptoms within 72 hours of a diagnosed concussion. A Mann-Whitney U test was used to compare days to symptom resolution between groups with α = 0.05.

RESULTS

Of the 539 participants, 250 (46.3%) reported sleep-related symptoms. Participants with sleep-related symptoms took significantly longer (U = 30656, p = 0.002) to report symptom resolution at rest (median [full range] = 8.00[0-423]) as compared to participants who did not report sleep-related symptoms (6.00[0-243] days).

CONCLUSION

Collegiate athletes that report sleep-related symptoms immediately following concussion (<72 hours) were observed to take, on median, two days longer to achieve symptom resolution at rest when compared to athletes who did not endorse the same symptoms.

Collegiate Athletes With Diabetes: Baseline Medical Comorbidities and Preseason Concussion Testing Performance

CONTEXT

People with diabetes mellitus (DM) are at increased risk for adverse health events and complications throughout their lifetime. Whether DM significantly affects collegiate athletes' concussion baseline testing performance remains unclear.

OBJECTIVES

To (1) describe the prevalence of DM and associated comorbidities and (2) compare concussion baseline testing performance between student-athletes with DM and student-athletes without DM (NoDM).

DESIGN

Retrospective, cross-sectional study.

SETTING

University.

PATIENTS OR OTHER PARTICIPANTS

Using the Concussion, Assessment, Research and Education (CARE) Consortium research database, we matched athletes with self-reported DM (N = 229) by institution, sex, age, sport, position, testing year, and concussion history to athletes with NoDM (N = 229; total sample mean age = 19.6 ± 1.4 years, women = 42%).

MAIN OUTCOME MEASURE(S)

Descriptive statistics and χ2 tests of independence with subsequent odds ratios were calculated. Independent-samples t tests compared baseline symptoms, neurocognitive testing, and balance performance between athletes with DM and athletes with NoDM. Effect sizes were determined for significant group differences.

RESULTS

At baseline, athletes with DM had higher rates of self-reported pre-existing balance disorders, sleep disorders, seizure disorders, motion sickness, learning disorders, vision and hearing problems, psychiatric disorders, depression, bipolar disorder, nonmigraine headaches, and meningitis than athletes with NoDM (P values < .05). We found balance differences between groups (P = .032, Cohen d = 0.17) such that, on average, athletes with DM had 1 additional error on the Balance Error Scoring System (DM = 13.4 ± 6.5; NoDM = 12.1 ± 5.9). No other comparisons yielded significant results.

CONCLUSIONS

Although athletes with DM had high rates of self-reported balance disorders, sleep disorders, seizures, and meningitis, their baseline neurocognitive testing results were largely identical to those of athletes with NoDM. Our findings suggested that nonclinically meaningful differences were present in concussion baseline balance testing but no significant differences were noted in cognitive testing; however, the effect of DM on concussion recovery remains unknown.

Classification of blood pressure during sleep impacts designation of nocturnal nondipping

The identification of nocturnal nondipping blood pressure (< 10% drop in mean systolic blood pressure from awake to sleep periods), as captured by ambulatory blood pressure monitoring, is a valuable element of risk prediction for cardiovascular disease, independent of daytime or clinic blood pressure measurements. However, capturing measurements, including determination of wake/sleep periods, is challenging. Accordingly, we sought to evaluate the impact of different definitions and algorithms for defining sleep onset on the classification of nocturnal nondipping. Using approaches based upon participant self-reports, applied definition of a common sleep period (12 am -6 am), manual actigraphy, and automated actigraphy we identified changes to the classification of nocturnal nondipping, and conducted a secondary analysis on the potential impact of an ambulatory blood pressure monitor on sleep. Among 61 participants in the Eastern Caribbean Health Outcomes Research Network hypertension study with complete ambulatory blood pressure monitor and sleep data, the concordance for nocturnal nondipping across methods was 0.54 by Fleiss' Kappa (depending on the method, 36 to 51 participants classified as having nocturnal nondipping). Sleep quality for participants with dipping versus nondipping was significantly different for total sleep length when wearing the ambulatory blood pressure monitor (shorter sleep duration) versus not (longer sleep duration), although there were no differences in sleep efficiency or disturbances. These findings indicate that consideration of sleep time measurements is critical for interpreting ambulatory blood pressure. As technology advances to detect blood pressure and sleep patterns, further investigation is needed to determine which method should be used for diagnosis, treatment, and future cardiovascular risk.

Investigating post-mild traumatic brain injury neuromuscular function and musculoskeletal injury risk: A protocol for a prospective, observational, case-controlled study in service members and active individuals

INTRODUCTION

Musculoskeletal injury (MSKI) risk is increased following mild traumatic brain injury (mTBI). Increased MSKI risk is present up to 2 years following post-mTBI return-to-duty/activity relative to both non-mTBI peers and to their pre-mTBI selves across a range of populations, including military service members, and professional, college and high school athletes. Despite the well documented increased post-mTBI MSKI risk, the underlying neuromuscular mechanisms contributing to this increased risk have yet to be definitively determined. A number of potential mechanisms have been suggested (eg, aberrant kinematics, dynamic balance impairments, lower voluntary muscle activation), but none have been confirmed with a comprehensive, prospective study. This study aims to: (1) elucidate the neuromuscular control mechanisms following mTBI that contribute to increased MSKI risk, and (2) prospectively track patient outcomes (up to 12 months; MSKI occurrences and patient-reported outcomes (PRO)).

METHODS AND ANALYSIS

This is a multicentre prospective, case-matched control observational study to identify deficiencies in neuromuscular function following mTBI that may contribute to increased MSKI risk. Participants (aim to recruit 148, complete data collection on 124) will be classified into two cohorts; mTBI and control. All participants will undergo longitudinal (initial, 6 weeks post-initial, 12 weeks post-initial) comprehensive three-dimensional biomechanical (jump-landing; single leg hop; cut; gait), neuromuscular (interpolated twitch technique, muscular ramp contraction) and sensory (joint repositioning; light touch sensation) assessments to elucidate the underlying neuromuscular control mechanisms post-mTBI that may contribute to increased MSKI. Occurrences of MSKI and PROs (National Institutes of Health Patient-Reported Outcome Measurement Information System: Physical Function, Pain Interference, Depression, Anxiety; Brief Resilience Scale; Tampa Scale of Kinesiophobia), will be tracked monthly (up to 1 year) via electronic data capture platforms.

ETHICS AND DISSEMINATION

The study received approval from the Walter Reed National Military Medical Center Institutional Review Board. Results will be made available to the associated funding agency and other researchers via conference proceedings and journal articles.

TRIAL REGISTRATION NUMBER

NCT05122728.

Lower Extremity Somatosensory Function Throughout Concussion Recovery: A Prospective Cohort Study

OBJECTIVE

Balance impairments may suggest somatosensory disruption beyond concussion clinical recovery, but somatosensory subsystems have never been directly assessed. Our objective was to examine somatosensory function between individuals with a concussion and healthy matched-controls at acute (<7 days) and asymptomatic (<72 hours of being symptom-free) time points.

SETTING

Laboratory.

PARTICIPANTS

Participants with a concussion and matched controls ( n = 24; 58% male, age: 19.3 ± 1.1 years, mass: 70.3 ± 16.4 kg, height: 177.3 ± 12.7 cm).

DESIGN

Prospective cohort.

MAIN MEASURES

Somatosensory assessments on the dominant limb at both time points included: (1) plantar touch sensation threshold via Semmes-Weinstein monofilaments, (2) plantar pressure pain threshold via algometry, and (3) knee absolute passive joint repositioning (PJR) error via Biodex across 3 arcs (105°-75°, 30°-60°, 90°-45° knee-flexion). We used mixed-model analyses of variance, post hoc Tukey honestly significant difference t tests with mean difference, 95% CI, and Hedges' g effect sizes to examine outcomes.

RESULTS

Touch sensation had a group effect with the concussion cohort needing 0.95 grams of force (gf) more relative to controls (95% CI: 0.03 to 1.87; P = .043). No touch sensation interaction was present, but medium and large effects were observed for greater gf needed among the concussed cohort at the acute (1.11 gf; 95% CI: 0.17 to 2.05; g = 0.96) and asymptomatic time points (0.79 gf; 95% CI: -0.15 to 1.73; g = 0.73). No plantar pressure pain threshold effects were observed ( P ≥ .311), with negligible pressure difference magnitudes at the acute (0.26 pound force [lbf]/cm 2 ; 95% CI: -1.54 to 2.06; g = 0.13) and medium magnitudes at the asymptomatic time points (0.99 lbf/cm 2 ; 95% CI: -0.81 to 2.80; g = 0.42) for the concussed cohort needing more pressure to detect pain. The 30° to 60° PJR had a time effect, with asymptomatic time point having 3.12° better accuracy (95% CI: 1.23° to 5.02; P = .002). The concussed cohort had small-to-medium magnitude differences relative to controls at the acute time point for PJR during 105° to 75° (0.89°; g = 0.30) and 90° to 45° (0.62°; g = 0.17), but not 30° to 60° (-1.75°; g = -0.40).

CONCLUSIONS

Individuals with a concussion exhibited large effects for diminished plantar touch sensation and small to medium effects for inhibited plantar pressure pain sensation compared with controls, which may indicate altered somatosensory function. Negligible PJR differences suggest knee joint position sense is not altered post-concussion. Pre- and postconcussion examination is warranted to understand causal somatosensory mechanisms.

Electroencephalographic Changes in Sleep During Acute and Subacute Phases After Sports-Related Concussion

Purpose

Little is known about sleep after a concussion, a form of mild traumatic brain injury. Given the importance of sleep for both maintaining brain health and recovery from injury, we sought to examine sleep acutely and subacutely after concussion.

Methods

Athletes who experienced a sports-related concussion were invited to participate. Participants underwent overnight sleep studies within 7 days of the concussion (acute phase), and again eight-weeks after the concussion (subacute phase). Changes in sleep from both the acute and subacute phases were compared to population normative values. Additionally, changes in sleep from acute to subacute phase were analysed.

Results

When compared to normative data, the acute and subacute phases of concussion showed longer total sleep time (p < 0.005) and fewer arousals (p < 0.005). The acute phase showed longer rapid eye movement sleep latency (p = 0.014). The subacute phase showed greater total sleep spent in Stage N3% (p = 0.046), increased sleep efficiency (p < 0.001), shorter sleep onset latency (p = 0.013), and reduced wake after sleep onset (p = 0.013). Compared to the acute phase, the subacute phase experienced improved sleep efficiency (p = 0.003), reduced wake after sleep onset (p = 0.02), and reduced latencies for both stage N3 sleep (p = 0.014) and rapid eye movement sleep (p = 0.006).

Conclusion

This study indicated sleep during both the acute and subacute phases of SRC was characterised by longer and less disrupted sleep, along with improvements in sleep from the acute to subacute phases of SRC.

Single-Leg Hop Stabilization Throughout Concussion Recovery: A Preliminary Biomechanical Assessment

CONTEXT

Aberrant movement patterns among individuals with concussion history have been reported during sport-related movement. However, the acute postconcussion kinematic and kinetic biomechanical movement patterns during a rapid acceleration-deceleration task have not been profiled and leaves their progressive trajectory unknown. Our study aimed to examine single-leg hop stabilization kinematics and kinetics between concussed and healthy-matched controls acutely (≤7 d) and when asymptomatic (≤72 h of symptom resolution).

DESIGN

Prospective, cohort laboratory study.

METHODS

Ten concussed (60% male; 19.2 [0.9] y; 178.7 [14.0] cm; 71.3 [18.0] kg) and 10 matched controls (60% male; 19.5 [1.2] y; 176.1 [12.6] cm; 71.0 [17.0] kg) completed the single-leg hop stabilization task under single and dual task (subtracting by 6's or 7's) at both time points. Participants stood on a 30-cm tall box set 50% of their height behind force plates while in an athletic stance. A synchronized light was illuminated randomly, queuing participants to initiate the movement as rapidly as possible. Participants then jumped forward, landed on their nondominant leg, and were instructed to reach and maintain stabilization as fast as possible upon ground contact. We used 2 (group) × 2 (time) mixed-model analyses of variance to compare single-leg hop stabilization outcomes separately during single and dual task.

RESULTS

We observed a significant main group effect for single-task ankle plantarflexion moment, with greater normalized torque (mean difference = 0.03 N·m/body weight; P = .048, g = 1.18) for concussed individuals across time points. A significant interaction effect for single-task reaction time indicated that concussed individuals had slower performance acutely relative to asymptomatic (mean difference = 0.09 s; P = .015, g = 0.64), while control group performance was stable. No other main or interaction effects for single-leg hop stabilization task metrics were present during single and dual task (P ≥ .051).

CONCLUSIONS

Greater ankle plantarflexion torque coupled with slower reaction time may indicate stiff, conservative single-leg hop stabilization performance acutely following concussion. Our findings shed preliminary light on the recovery trajectories of biomechanical alterations following concussion and provide specific kinematic and kinetic focal points for future research.

Lower-Extremity Neuromuscular Function Following Concussion: A Preliminary Examination

CONTEXT

Neuromuscular function is altered acutely following concussion and theoretically linked to the subsequent postconcussion musculoskeletal injury risk. Existing research has only examined voluntary muscle activation, limiting mechanistic understanding. Therefore, our study aimed to examine voluntary and involuntary muscle activation between college-aged, concussed individuals when symptom-free and healthy matched controls.

DESIGN

Prospective, cross-sectional cohort laboratory study.

METHODS

Concussed and healthy participants (n = 24; 58% male, age: 19.3 [1.1] y, mass: 70.3 [16.4] kg, height: 177.3 [12.7] cm) completed the superimposed burst (SB) neuromuscular assessment on their dominant limb within 72 hours after self-reporting asymptomatic (22.4 [20.2] d postinjury). Unnormalized and bodyweight-normalized quadriceps maximal voluntary isometric contraction torque (in newton meters), unnormalized and bodyweight-normalized electrically stimulated SB torque, pain (numeric 1-10) during SB, and the central activation ratio (in percentage) were assessed via the SB. Parametric and nonparametric analyses, 95% confidence intervals (95% CIs), and Hedges g (parametric) and Spearman ρ (nonparametric) effect sizes were used to examine group differences (α = .05).

RESULTS

The maximal voluntary isometric contraction torque (concussed: 635.60 N·m [300.93] vs control: 556.27 N·m [182.46]; 95% CI, -131.36 to 290.02; P = .443; d = 0.33), SB torque (concussed: 203.22 N·m [97.17], control: 262.85 N·m [159.07]; 95% CI, -171.22 to 51.97; P = .280; d = -0.47), and central activation ratio (concussed: 72.16% [17.16], control: 70.09% [12.63]; 95% CI, -10.68 to 14.83; P = .740; d = 0.14) did not differ between the concussed and control groups regardless of bodyweight normalization (P ≥ .344). Pain during the SB was significantly higher with a medium effect for participants with a concussion versus healthy controls (concussed: median = 7, control: median = 5; P = .046; ρ = -0.42).

DISCUSSION

These findings suggest concussed participants do not have statistically altered voluntary or involuntary quadricep neuromuscular function once asymptomatic compared with controls. Therefore, the elevated postconcussion musculoskeletal injury risk may not be attributed to lower-extremity muscle activation. Concussed participants displayed greater pain perception during the SB, which suggests somatosensory or perception changes requiring further examination.

Effects of docosahexaenoic acid and eicosapentaoic acid supplementation on white matter integrity after repetitive sub-concussive head impacts during American football: Exploratory neuroimaging findings from a pilot RCT

Context

Repetitive sub-concussive head impacts (RSHIs) are common in American football and result in changes to the microstructural integrity of white matter. Both docosahexaenoic acid (DHA) and eicosapentaoic acid (EPA) supplementation exerted neuroprotective effects against RSHIs in animal models and in a prior study in football players supplemented with DHA alone.

Objective

Here, we present exploratory neuroimaging outcomes from a randomized controlled trial of DHA + EPA supplementation in American football players. We hypothesized that supplementation would result in less white matter integrity loss on diffusion weighted imaging over the season.

Design setting participants

We conducted a double-blind placebo-controlled trial in 38 American football players between June 2019 and January 2020.

Intervention

Participants were randomized to the treatment (2.442 g/day DHA and 1.020 g/day EPA) or placebo group for five times-per-week supplementation for 7 months. Of these, 27 participants were included in the neuroimaging data analysis (n = 16 placebo; n = 11 DHA + EPA).

Exploratory outcome measures

Changes in white matter integrity were quantified using both voxelwise diffusion kurtosis scalars and deterministic tractography at baseline and end of season. Additional neuroimaging outcomes included changes in regional gray matter volume as well as intra-regional, edge-wise, and network level functional connectivity. Serum neurofilament light (NfL) provided a peripheral biomarker of axonal damage.

Results

No voxel-wise between-group differences were identified on diffusion tensor metrics. Deterministic tractography using quantitative anisotropy (QA) revealed increased structural connectivity in ascending corticostriatal fibers and decreased connectivity in long association and commissural fibers in the DHA+EPA group compared to the placebo group. Serum NfL increases were correlated with increased mean (ρ = 0.47), axial (ρ = 0.44), and radial (ρ = 0.51) diffusivity and decreased QA (ρ = -0.52) in the corpus callosum and bilateral corona radiata irrespective of treatment group. DHA + EPA supplementation did preserve default mode/frontoparietal control network connectivity (g = 0.96, p = 0.024).

Conclusions

These exploratory findings did not provide strong evidence that DHA + EPA prevented or protected against axonal damage as quantified via neuroimaging. Neuroprotective effects on functional connectivity were observed despite white matter damage. Further studies with larger samples are needed to fully establish the relationship between omega-3 supplementation, RSHIs, and neuroimaging biomarkers.

Trial registration

ClinicalTrials.gov-NCT04796207.

The Association Between Sleep Breathing Impairment Index and Cardiovascular Risk in Male Patients with Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea (OSA) is related to multiple complications including insulin resistance (IR), endothelial dysfunction, and increased risk of cardiovascular disease (CVD). The apnea-hypopnea index (AHI) was widely used to measure OSA severity but poorly correlated with complications above. This study aimed to evaluate whether a new metric, the sleep breathing impairment index (SBII), was associated with cardiovascular risk in patients with OSA.

METHODS

This study enrolled 140 consecutive male OSA patients without overt atherosclerotic CVD events, including coronary heart disease, stroke, peripheral vascular disease, or heart failure. Data on baseline medical history, anthropometric and polysomnographic parameters, fasting biochemical measurements and endothelial function tests, and common questionnaires were collected. The SBII was calculated by the product of the duration of each obstructive event and the associated desaturation area. The primary outcome was the moderate-to-high Framingham 10-year CVD risk.

RESULTS

The median age of enrolled patients was 40 (35-48) years. Eighty subjects had a moderate-to-high Framingham CVD risk. Patients with SBII in the third and fourth quartile had an increased proportion of moderate-to-high Framingham CVD risk with an adjusted OR 6.28 (95% CI 1.10-36.04) and 11.78 (95% CI 1.25-111.38). Significant association was not demonstrated in AHI and the Framingham CVD risk.

CONCLUSION

Higher SBII was associated with an increased 10-year CVD risk after adjusting for multiple potential confounding factors. Additional valuable information derived from polysomnography besides AHI deserves to be paid more attention.

Longitudinal associations between adolescents' sleep and adjustment: Respiratory sinus arrhythmia as a moderator

Sleep and autonomic nervous system functioning are important bioregulatory systems. Poor sleep and low baseline respiratory sinus arrhythmia (RSA), a measure of parasympathetic nervous system activity, are associated with externalizing behaviors and depressive symptoms in youth. Rarely, however, have measures of these systems been examined conjointly. The present study examined baseline RSA (RSA-B) as a moderator of longitudinal relations between adolescent sleep and adjustment. Participants were 256 adolescents (52% girls, 66% White/European American, 34% Black/African American) from small towns and surrounding rural communities in the southeastern United States. Sleep (minutes, efficiency, variability in minutes and efficiency) was assessed at age 15 via actigraphs across seven nights. RSA-B was derived from electrocardiogram data collected at rest. Adolescents self-reported externalizing problems and depressive symptoms at ages 15 and 17. Controlling for age 15 adjustment, findings generally demonstrated that sleep predicted age 17 adjustment particularly at higher (rather than lower) levels of RSA-B, such that adolescents with good sleep (more minutes and lower variability) and high RSA-B were at lowest risk for maladjustment. The results highlight the value of examining multiple bioregulatory processes conjointly and suggest that promoting good sleep habits and regulation of physiological arousal should support adolescent adjustment.

Compounding Effects of Traumatic Brain Injury, Military Status, and Other Factors on Pittsburgh Sleep Quality Index: A Meta-analysis

INTRODUCTION

Traumatic brain injury (TBI) or concussion is a known risk factor for multiple adverse health outcomes, including disturbed sleep. Although prior studies show adverse effects of TBI on sleep quality, its compounding effect with other factors on sleep is unknown. This meta-analysis aimed to quantify the effects of TBI on subjective sleep quality in the context of military status and other demographic factors.

MATERIALS AND METHODS

A programmatic search of PubMed database from inception to June 2020 was conducted to identify studies that compared subjective sleep quality measured using Pittsburgh Sleep Quality Index (PSQI) in individuals with TBI relative to a control group. The meta-analysis included group-wise standard mean difference (SMD) and 95% CI. Pooled means and SDs were obtained for TBI and non-TBI groups with and without military service, and meta-regression was conducted to test for group effects. Exploratory analysis was performed to test for the effect of TBI, non-head injury, military status, sex, and age on sleep quality across studies.

RESULTS

Twenty-six articles were included, resulting in a combined total of 5,366 individuals (2,387 TBI and 2,979 controls). Overall, individuals with TBI self-reported poorer sleep quality compared to controls (SMD = 0.63, 95% CI: 0.45 to 0.80). Subgroup analysis revealed differences in the overall effect of TBI on PSQI, with a large effect observed in the civilian subgroup (SMD: 0.80, 95% CI: 0.57 to 1.03) and a medium effect in the civilian subgroup with orthopedic injuries (SMD: 0.40, 95% CI: 0.13 to 0.65) and military/veteran subgroup (SMD: 0.43, 95% CI: 0.14 to 0.71). Exploratory analysis revealed that age and history of military service significantly impacted global PSQI scores.

CONCLUSIONS

Poor sleep quality in TBI cohorts may be due to the influence of multiple factors. Military/veteran samples had poorer sleep quality compared to civilians even in the absence of TBI, possibly reflecting unique stressors associated with prior military experiences and the sequelae of these stressors or other physical and/or psychological traumas that combine to heightened vulnerability. These findings suggest that military service members and veterans with TBI are particularly at a higher risk of poor sleep and its associated adverse health outcomes. Additional research is needed to identify potential exposures that may further heighten vulnerability toward poorer sleep quality in those with TBI across both civilian and military/veteran populations.

Daily Morning Blue Light Therapy Improves Daytime Sleepiness, Sleep Quality, and Quality of Life Following a Mild Traumatic Brain Injury

OBJECTIVE

Identify the treatment effects of 6 weeks of daily 30-minute sessions of morning blue light therapy compared with placebo amber light therapy in the treatment of sleep disruption following mild traumatic brain injury.

DESIGN

Placebo-controlled randomized trial.

PARTICIPANTS

Adults aged 18 to 45 years with a mild traumatic brain injury within the past 18 months (n = 35).

MAIN OUTCOME MEASURES

Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, Beck Depression Inventory II, Rivermead Post-concussion Symptom Questionnaire, Functional Outcomes of Sleep Questionnaire, and actigraphy-derived sleep measures.

RESULTS

Following treatment, moderate to large improvements were observed with individuals in the blue light therapy group reporting lower Epworth Sleepiness Scale (Hedges' g = 0.882), Beck Depression Inventory II (g = 0.684), Rivermead Post-concussion Symptom Questionnaire chronic (g = 0.611), and somatic (g = 0.597) symptoms, and experiencing lower normalized wake after sleep onset (g = 0.667) than those in the amber light therapy group. In addition, individuals in the blue light therapy group experienced greater total sleep time (g = 0.529) and reported improved Functional Outcomes of Sleep Questionnaire scores (g = 0.929) than those in the amber light therapy group.

CONCLUSION

Daytime sleepiness, fatigue, and sleep disruption are common following a mild traumatic brain injury. These findings further substantiate blue light therapy as a promising nonpharmacological approach to improve these sleep-related complaints with the added benefit of improved postconcussion symptoms and depression severity.

Should We Lose Sleep Over Sleep Disturbances After Sports-Related Concussion? A Scoping Review of the Literature

OBJECTIVE

A single, severe traumatic brain injury can result in chronic sleep disturbances that can persist several years after the incident. In contrast, it is unclear whether there are sleep disturbances after a sports-related concussion (SRC). Considering growing evidence of links between sleep disturbance and neurodegeneration, this review examined the potential links between diagnosed SRCs and sleep disturbances to provide guidance for future studies.

METHODS

The scoping review undertook a systematic search of key online databases (Scopus, MEDLINE, SportDiscus, and Web of Science) using predetermined search terms for any articles that examined sleep after concussion. A screening criterion using agreed inclusion and exclusion criteria was utilized to ensure inclusion of relevant articles.

DESIGN

This scoping review is guided by the PRSIMA Scoping Review report.

RESULTS

Ten studies met the inclusion criteria, reporting on 896 adults who had experienced an SRC. Comparison with 1327 non-SRC adults occurred in 8 studies. Nine studies subjectively examined sleep, of which all but one study reported sleep disturbances after an SRC. Three studies objectively measured sleep, with 2 studies indicating large coefficients of variation of sleep duration, suggesting a range of sleep responses after an SRC. The only study to examine overnight polysomnography showed no differences in sleep metrics between those with and without an SRC. No studies examined interventions to improve sleep outcomes in people with concussion.

CONCLUSIONS

This scoping review indicates preliminary evidence of sleep disturbances following an SRC. The heterogeneity of methodology used in the included studies makes consensus on the results difficult. Given the mediating role of sleep in neurodegenerative disorders, further research is needed to identify physiological correlates and pathological mechanisms of sleep disturbances in SRC-related neurodegeneration and whether interventions for sleep problems improve recovery from concussion and reduce the risk of SRC-related neurodegeneration.

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.

Mood, Psychological, and Behavioral Factors of Health-Related Quality of Life Throughout Recovery From Sport Concussion

OBJECTIVE

To measure alterations in mood, psychological, and behavioral factors in collegiate athletes throughout recovery from sport concussion (SC) compared with matched controls.

SETTING

University research laboratory.

PARTICIPANTS

Twenty (55% female) division I collegiate athletes with SC (19.3 ± 1.08 years old, 1.77 ± 0.11 m, 79.6 ± 23.37 kg) and 20 (55% female) uninjured matched controls (20.8 ± 2.17 years old, 1.77 ± 0.10 m, 81.9 ± 23.45 kg).

DESIGN

Longitudinal case control.

MAIN MEASURES

Self-reported concussion-related symptoms, anxiety, resilience, stigma, sleep disturbance, fatigue, and appetite were assessed at 3 time points in the SC group: T1 (≤72 hours of SC), T2 (7 days after T1), and TF (after symptom resolution). Control participants were evaluated at similar intervals. Group and group-by-sex differences were assessed using repeated-measures analyses of variance. Post hoc analyses were performed with Tukey's honestly significant difference (HSD) and paired-sample t tests.

RESULTS

The SC group had greater sleep disturbance than controls at T1 (P = .001; d = 1.21) and endorsed greater stigma at all time points (P ≤ .03; d ≥ 0.80). Stigma (F(2) = 3.68; P = 0.03; η2p = 0.12), sleep disturbance (F(2) = 5.27; P = .008; η2p = 0.15), and fatigue (F(2) = 3.46; P = .04; η2p = 0.11) improved throughout recovery in those with SC only. No differences were observed between males and females (P > .05).

CONCLUSION

Sleep disturbance and stigma were negatively affected by SC, highlighting potential areas for clinical interventions to maximize recovery in males and females.

Daily Morning Blue Light Therapy for Post-mTBI Sleep Disruption: Effects on Brain Structure and Function

Background: Mild traumatic brain injuries (mTBIs) are associated with novel or worsened sleep disruption. Several studies indicate that daily morning blue light therapy (BLT) is effective for reducing post-mTBI daytime sleepiness and fatigue. Studies demonstrating changes in brain structure and function following BLT are limited. The present study's purpose is to identify the effect of daily morning BLT on brain structure and functional connectivity and the association between these changes and self-reported change in post-mTBI daytime sleepiness. Methods: A total of 62 individuals recovering from a mTBI were recruited from two US cities to participate in a double-blind placebo-controlled trial. Eligible individuals were randomly assigned to undergo 6 weeks of 30 min daily morning blue or placebo amber light therapy (ALT). Prior to and following treatment all individuals completed a comprehensive battery that included the Epworth Sleepiness Scale as a measure of self-reported daytime sleepiness. All individuals underwent a multimodal neuroimaging battery that included anatomical and resting-state functional magnetic resonance imaging. Atlas-based regional change in gray matter volume (GMV) and region-to-region functional connectivity from baseline to post-treatment were the primary endpoints for this study. Results: After adjusting for pre-treatment GMV, individuals receiving BLT had greater GMV than those receiving amber light in 15 regions of interest, including the right thalamus and bilateral prefrontal and orbitofrontal cortices. Improved daytime sleepiness was associated with greater GMV in 74 ROIs, covering many of the same general regions. Likewise, BLT was associated with increased functional connectivity between the thalamus and both prefrontal and orbitofrontal cortices. Improved daytime sleepiness was associated with increased functional connectivity between attention and cognitive control networks as well as decreased connectivity between visual, motor, and attention networks (all FDR corrected p < 0.05). Conclusions: Following daily morning BLT, moderate to large increases in both gray matter volume and functional connectivity were observed in areas and networks previously associated with both sleep regulation and daytime cognitive function, alertness, and attention. Additionally, these findings were associated with improvements in self-reported daytime sleepiness. Further work is needed to identify the personal characteristics that may selectively identify individuals recovering from a mTBI for whom BLT may be optimally beneficial.

Effects of sleep disturbance on functional and physiological outcomes in collegiate athletes: A scoping review

OBJECTIVE

To investigate sleep disturbances and circadian timing changes on functional and physiological correlates specifically in collegiate athletes.

DESIGN

Scoping Review.

DATA SOURCES

PubMed MEDLINE, SPORT-Discus, CINAHL, ERIC ProQuest, Web of Science.

ELIGIBILITY CRITERIA

Articles in English, studying college athletes 18-24 years old, employing a sleep measurement, and a comparison measure of cognitive, academic performance, athletic performance, injury rate, biomarkers and physiological measures, or imaging.

RESULTS

Thirty articles met inclusion criteria. There was wide range of study design, sport studied, modality used to measure sleep, frequency of sleep measurements, and functional and physiological outcomes across studies. Sleep measurements varied greatly in frequency of data collection and type of measurement tool, with the majority using a sleep questionnaire. While all variables of interest were represented within the review, most had a focus on cognitive performance, athletic performance, or injury rate as a function of sleep. Studies using biomarkers and physiological measures or imaging were largely underrepresented. Few studies used biomarkers and physiological measures, and one study used imaging measures. Most studies in this review reported negative cognitive and academic outcomes with worse sleep quality and quantity.

CONCLUSIONS

Sleep is critical to maintaining optimal health and collegiate athletes represent a unique population given their unique time constraints, stresses, and sleep behaviors. Findings on athletic performance and injury rate as a function of sleep were mixed. Employing standardized objective methodologies in future work will allow for better understanding of the influence of sleep on the overall well-being and performance of college athletes.

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.

Insomnia and daytime sleepiness: risk factors for sports-related concussion

OBJECTIVE/BACKGROUND

Poor quality and inadequate sleep are associated with impaired cognitive, motor, and behavioral components of sport performance and increased injury risk. While prior work identifies sports-related concussions as predisposing factors for poor sleep, the role of sleep as a sports-related concussion risk factor is unknown. The purpose of this study was to quantify the effect of poor sleep quality and insomnia symptoms on future sports-related concussion risk.

PATIENTS/METHODS

In this study, 190 NCAA Division-1 athletes completed a survey battery, including the Insomnia Severity Index (ISI) and National Health and Nutrition Examination Survey (NHANES) Sleep module. Univariate risk ratios for future sports-related concussions were computed with ISI and NHANES sleepiness scores as independent predictors. An additional multiple logistic regression model including sport, sports-related concussion history, and significant univariate predictors jointly assessed the odds of sustaining a concussion.

RESULTS

Clinically moderate-to-severe insomnia severity (RR = 3.13, 95% CI: 1.320-7.424, p = 0.015) and excessive daytime sleepiness two or more times per month (RR = 2.856, 95% CI: 0.681-11.977, p = 0.037) increased concussion risk. These variables remained significant and comparable in magnitude in a multivariate model adjusted for sport participation.

CONCLUSION

Insomnia and daytime sleepiness are independently associated with increased sports-related concussion risk. More completely identifying bidirectional relationships between concussions and sleep requires further research. Clinicians and athletes should be cognizant of this relationship and take proactive measures - including assessing and treating sleep-disordered breathing, limiting insomnia risk factors, improving sleep hygiene, and developing daytime sleepiness management strategies - to reduce sports-related concussion risk and support overall athletic performance.