Predictors of clinical recovery from concussion: a systematic review

Characteristics of Pediatric Mild Traumatic Brain Injury and Recovery in a Concussion Clinic Population

IMPORTANCE

Pediatric mild traumatic brain injury (TBI) and concussion are a public health challenge with up to 30% of patients experiencing prolonged recovery. Pediatric patients presenting to concussion clinics often have ongoing impairments and may be at increased risk for persistent symptoms. Understanding this population is critical for improved prognostic estimates and optimal treatment.

OBJECTIVE

To describe pediatric patients presenting to concussion clinics and characterize factors associated with their recovery.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study included patients enrolled at multicenter concussion specialty clinics from the Four Corners Youth Consortium from December 2017 to July 2019, with up to 12-month follow-up. Patients were eligible if they were aged 5 to 18.99 years with a diagnosis of mild TBI or concussion presenting to participating clinics within 8 weeks of injury. Patients were excluded if the patient or their parents were unable to read or sign the consent document, or if the patient had a Glasgow Coma Scale score less than 13 or a penetrating injury. Data were analyzed from February 2019 to April 2020.

EXPOSURES

Diagnosis of mild TBI or concussion.

MAIN OUTCOMES AND MEASURES

This study used National Institute of Neurological Disorders and Stroke common data elements, including data on demographic characteristics, injury details, history, neurological and neuropsychological assessments, and treatment.

RESULTS

A total of 600 patients were consecutively enrolled, among whom 324 (54.0%) were female and 435 (72.5%) were adolescents (ie, aged 13-18 years). A higher proportion of girls and women (248 patients [76.5%]) were adolescents compared with boys and men (187 patients [67.8%]) (P = .02), and girls and women reported significantly more preexisting anxiety compared with boys and men (80 patients [26.7%] vs 46 patients [18.7%]; P = .03). Significantly more adolescents reported preexisting migraines compared with preadolescents (82 patients [20.9%] vs 15 patients [10.9%]; P = .01). Girls and women recovered more slowly than boys and men (persistent symptoms after injury: week 4, 217 patients [81.6%] vs 156 patients [71.2%]; week 8, 146 patients [58.9%] vs 89 patients [44.3%]; week 12, 103 patients [42.6%] vs 58 patients [30.2%]; P = .01). Patients with history of migraine or anxiety or depression recovered more slowly than those without, regardless of sex.

CONCLUSIONS AND RELEVANCE

These findings suggest that identification of subgroups of pediatric patients with mild TBI or concussion at risk for prolonged recovery could aid in better prognostic estimates and more targeted treatment interventions.

Preliminary investigation of a multimodal enhanced brain function index among high school and collegiate concussed male and female athletes

Objective: The primary purpose of this study was to examine the longitudinal effects of sports-related concussion (SRC) on a multi-faceted assessment battery which included neuropsychological testing, symptom reporting, and enhanced brain function index (eBFI) among athletes with and without SRC. A secondary purpose was to explore longitudinal sex differences among these measures in athletes with and without SRC. Methods: A case-control, repeated-measures design was used for this study. A total of 186 athletes (concussed group:n= 87 controls:n= 99) participated in the study. A repeated-measures design was used in which each athlete was tested at four time points following an SRC: within 72 h of injury (Day 0; 2.0 ± 0.9 days following injury), 5 days following injury (Day 5; 5.0 ± 0.0), at return to play (RTP; 18.3 ± 13.8 days following injury), and within 45 days following RTP (RTP45; 66.2 ± 19.0 days following injury). All analyses were conducted separately using a 2 (Group: concussed, control) × 2 (Sex: male, female) × 4 (Time:Day 0, Day 5, RTP, RTP45) univariate multi-level model including the random intercept for each participant. A higher eBFI score indicates a better performance. Alpha level was set aprior at .05. This study was registered on clinicaltrials.gov (Objective Brain Function Assessment of mTBI/Concussion in College/high school Athletes NCT02477943, NCT02661633, CAS 13-25 NCT03963804). Results: Concussed athletes exhibited impaired eBFI within 72 h of SRC and at Day 5 compared to controls (p<.001). Analysis of eBFI scores between male and female athletes revealed a main effect of sex (p=.05), with female athletes exhibiting lower eBFI (33.9 ± 30.7) relative to male athletes (40.4 ± 33.0), however, it did not indicate interactions between sex, group, and time (p's ≥ 0.786). Conclusion: The eBFI appears to be a useful tool in determining concussed athletes during the acute stages of an SRC. However, this index may lack the sensitivity to detect sex-related differences between groups at various time points during recovery.

The cost of a single concussion in American high school football: a retrospective cohort study

AIM

The potential financial burden of American football-related concussions (FRC) is unknown. Our objective was to describe the healthcare costs associated with an FRC and determine factors associated with increased costs.

METHODOLOGY/RESULTS

A retrospective cohort study of concussed high school football players presenting between November 2017 and March 2020 was undertaken; 144 male high school football players were included. Total costs were about $115,000, for an average direct healthcare cost of $800.10/concussion. Visiting the emergency department (β = 502.29, 95% CI: 105.79-898.61; p = 0.01), the initial post-concussion symptom scale score (β = 0.39, 95% CI: 0.11-0.66; p = 0.01) and a post-concussion syndrome diagnosis (β = 670.37, 95% CI: 98.96-1241.79; p = 0.02) were each independently associated with total costs.

CONCLUSION

A granular understanding of cost-driving factors associated with FRC is the first step in understanding the cost-effectiveness of prevention and treatment methods.

Behavioral, axonal, and proteomic alterations following repeated mild traumatic brain injury: Novel insights using a clinically relevant rat model

A history of mild traumatic brain injury (mTBI) is linked to a number of chronic neurological conditions, however there is still much unknown about the underlying mechanisms. To provide new insights, this study used a clinically relevant model of repeated mTBI in rats to characterize the acute and chronic neuropathological and neurobehavioral consequences of these injuries. Rats were given four sham-injuries or four mTBIs and allocated to 7-day or 3.5-months post-injury recovery groups. Behavioral analysis assessed sensorimotor function, locomotion, anxiety, and spatial memory. Neuropathological analysis included serum quantification of neurofilament light (NfL), mass spectrometry of the hippocampal proteome, and ex vivo magnetic resonance imaging (MRI). Repeated mTBI rats had evidence of acute cognitive deficits and prolonged sensorimotor impairments. Serum NfL was elevated at 7 days post injury, with levels correlating with sensorimotor deficits; however, no NfL differences were observed at 3.5 months. Several hippocampal proteins were altered by repeated mTBI, including those associated with energy metabolism, neuroinflammation, and impaired neurogenic capacity. Diffusion MRI analysis at 3.5 months found widespread reductions in white matter integrity. Taken together, these findings provide novel insights into the nature and progression of repeated mTBI neuropathology that may underlie lingering or chronic neurobehavioral deficits.

Physician Medical Assessment in a Multidisciplinary Concussion Clinic

Concussive brain injury (CBI) is encountered by clinicians in sports medicine, pediatrics, neurosurgery, neurology, physiatry, and primary care. There is no gold standard diagnostic test for CBI, nor is there consensus on what neuromusculoskeletal physical examination tests should be performed on patients who have sustained CBI. This article presents an approach to the history and physical examination of the patient who has sustained a CBI that is based on a review of the literature evidence and the authors' extensive experience with this patient population. Suggested components include an elemental neurological examination that emphasizes the oculomotor/ophthalmologic and vestibular systems, as well as appropriate musculoskeletal assessment of the craniocervical and upper shoulder girdle complex. The use of supplementary tests for CBI, including assessment of exercise tolerance using the Buffalo Concussion Treadmill Test and tests of neurocognitive function, can aid in the differential diagnosis of CBI. The proposed protocol is envisioned for initial and follow-up assessments in the clinic after CBI, as well as for those with more protracted signs or symptoms. If symptoms persist beyond 2 weeks in adults or 4 weeks in adolescents, then referral to a multidisciplinary center that focuses on CBI is recommended.

What is the risk of recurrent concussion in children and adolescents aged 5-18 years? A systematic review and meta-analysis

OBJECTIVE

We aimed to examine the risk of concussion in children with a previous history of concussion.

DESIGN

Systematic review and meta-analysis. The primary outcome was number of children with and without a previous lifetime history of concussion who sustained a diagnosed concussion within each study period. Risk of bias was assessed using the Newcastle-Ottawa Scale. A random effects model was used to estimate a pooled risk ratio (RR) with corresponding 95% CIs; results were summarised in forest plots.

DATA SOURCES

Four electronic databases (MEDLINE, Embase, CINAHL, SPORTDiscus) and selected reference lists were searched (PROSPERO registration No CRD42019135462).

ELIGIBILITY CRITERIA

Original English language peer-reviewed publications that compared concussion risk in children aged 5-18 years with and without a previous concussion history in which risk estimates were reported or able to be calculated.

RESULTS

Of 732 identified studies, 7 studies representing 23 411 children (risk of bias range, 7-9; maximum possible score=9) were included for meta-analysis. Pooled risk of sustaining a concussion was more than three times greater in children with a previous concussion compared with those with no previous concussion (RR=3.64; 95% CI: 2.68 to 4.96; p<0.0001; I ²=90.55%). Unreported sex-stratified data precluded direct comparison of concussion risk in male versus female athletes.

CONCLUSION

Previously concussed children have four times the risk of sustaining a concussion compared with those with no previous concussion history. This should be a consideration for clinicians in return to sport decision-making. Future studies examining subsequent recurrent concussion in youth sports must consider sex differences.

Systematic Review of Preinjury Mental Health Problems as a Vulnerability Factor for Worse Outcome After Sport-Related Concussion

Background:

It is difficult to predict who will experience prolonged health problems after sustaining a sport-related concussion.

Purpose:

To synthesize the literature and conduct a gap analysis on the association between preinjury mental health problems and clinical outcome from sport-related concussion.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Data sources were PubMed, PsycINFO, MEDLINE (and MEDLINE in Process), CINAHL, Cochrane Library, EMBASE, SPORTDiscus, Scopus, and Web of Science. Studies published before February 2019 that addressed preinjury mental health problems as a possible predictor of worse clinical outcome or clinical recovery from concussion were eligible for inclusion.

Results:

Of 4013 studies screened, 358 full texts were reviewed, and 12 studies involving 3761 participants (n = 471 [12.5%] with preexisting mental health problems) were ultimately included. The participants with a preinjury history of mental health problems were at greater risk for having persistent symptoms or worse outcome in 9 of 12 studies. The studies had major methodological differences, and most studies were not focused on mental health as a primary predictor or prognostic factor. Rather, they included it as a secondary or tertiary predictor. The sample sizes with preinjury mental health problems in most studies were small or very small (ie, <25). The age of onset, type, course, severity, and duration of mental health problems were not defined. The extent to which mental health problems were present before the season, during baseline testing, was not reported.

Conclusion:

Preinjury mental health problems appear to confer risk for worse clinical outcome after sport-related concussion. Future research is needed to (1) examine this risk factor in large representative populations of middle school students, high school students, and collegiate athletes; (2) quantify the risk for each mental health condition; (3) understand the mechanisms underlying this increased risk; and (4) develop more refined treatment and rehabilitation approaches for these student-athletes.

Prediction of Global Functional Outcome and Post-Concussive Symptoms after Mild Traumatic Brain Injury: External Validation of Prognostic Models in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) Study

The majority of traumatic brain injuries (TBIs) are categorized as mild, according to a baseline Glasgow Coma Scale (GCS) score of 13-15. Prognostic models that were developed to predict functional outcome and persistent post-concussive symptoms (PPCS) after mild TBI have rarely been externally validated. We aimed to externally validate models predicting 3-12-month Glasgow Outcome Scale Extended (GOSE) or PPCS in adults with mild TBI. We analyzed data from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) project, which included 2862 adults with mild TBI, with 6-month GOSE available for 2374 and Rivermead Post-Concussion Symptoms Questionnaire (RPQ) results available for 1605 participants. Model performance was evaluated based on calibration (graphically and characterized by slope and intercept) and discrimination (C-index). We validated five published models for 6-month GOSE and three for 6-month PPCS scores. The models used different cutoffs for outcome and some included symptoms measured 2 weeks post-injury. Discriminative ability varied substantially (C-index between 0.58 and 0.79). The models developed in the Corticosteroid Randomisation After Significant Head Injury (CRASH) trial for prediction of GOSE <5 discriminated best (C-index 0.78 and 0.79), but were poorly calibrated. The best performing models for PPCS included 2-week symptoms (C-index 0.75 and 0.76). In conclusion, none of the prognostic models for early prediction of GOSE and PPCS has both good calibration and discrimination in persons with mild TBI. In future studies, prognostic models should be tailored to the population with mild TBI, predicting relevant end-points based on readily available predictors.

A Scoping Review of Registered Clinical Studies on Mild Traumatic Brain Injury and Concussion (2000 to 2019)

BACKGROUND

While many patients with mild traumatic brain injury (mTBI) or concussion recover completely, prolonged postconcussion symptoms remain a challenge for patients and an opportunity for clinical research. This has led to numerous research initiatives over the last 2 decades.

OBJECTIVE

To review the characteristics of clinical studies on management of mTBI/concussion; and to examine their definitions of mTBI/concussion.

METHODS

This scoping review included all clinical studies on diagnosis and management of patients with mTBI/concussion registered at www.clinicaltrials.gov from 2000 to June/2019. The terms "mild TBI/concussion" were used for the primary search. Definitions of mTBI/concussion were obtained from the protocols. When a definition was missing in the website, the study's investigators were contacted for clarification.

RESULTS

There were 225 interventional and 95 observational studies. Most of the studies are focused on treatment (54.7%) or diagnosis (37.5%), while 3.4% examined preventive measures, 2.8% evaluated prognostic instruments, and 1.6% developed registries. Most of the studies in this American database were single-center initiatives led by American and Canadian institutions. The definitions of mTBI/concussion differed widely among 109 studies.

CONCLUSION

The results of this review suggest that most of the clinical studies are focused on diagnosis and non-pharmacological therapies for patients with mTBI/concussion. The large number of differing definitions of mTBI/concussion among the studies creates significant limitations when comparing studies. The requirements for registering research protocols on mTBI/concussion should include the necessity to state the definition being used. There is a need for consensus on a uniform definition of concussion.

Loss and recovery after concussion: Adolescent patients give voice to their concussion experience

Background

Most concussion studies have focused on the perspectives and expertise of health‐care providers and caregivers. Very little qualitative research has been done, engaging the adolescents who have suffered concussion and continue to experience the consequences in their everyday life.

Objective

To understand the experiences of recovery from the perspective of adolescent patients of concussion and to present the findings through their voices.

Methods

Two semi‐structured focus groups and two narrative interviews were conducted with a small group of 7 adolescents. Grounded theory was used to analyse the data.

Results

Participants experience continuing difficulty 1‐5 years after treatment with cognitive, emotional, social and mental well‐being. The overriding experience among older adolescents (17‐20) is a sense of irreversibility of the impact of concussion in all these areas.

Conclusion

There is a significant gap between the medical determination of recovery and what patients understand as recovery. Adolescents do not feel ‘recovered’ more than a year after they are clinically assessed as ‘good to go’. Systematic follow‐up and support from a multi‐disciplinary health‐care team would strengthen youths' coping and resilience.

Network Structure of Physical, Cognitive, and Emotional Symptoms at Preseason Baseline in Student Athletes with Attention-Deficit/ Hyperactivity Disorder

OBJECTIVE

Preexisting attention-deficit/hyperactivity disorder (ADHD) may be a risk factor for worse outcome following sport-related concussion. We used a statistical and psychometric approach known as network analysis to examine the architecture of physical, cognitive, and emotional symptoms at preseason baseline among student athletes with ADHD.

METHOD

A cohort of 44,527 adolescent student athletes completed baseline preseason testing with ImPACT® between 2009 and 2015. A subsample of athletes reporting a diagnosis of ADHD and at least one symptom were included in this study (N = 3,074; 14-18 years old, 32.7% girls). All participants completed the 22-item Post-Concussion Symptom Scale at preseason baseline.

RESULTS

Student athletes reported high frequencies of difficulty concentrating (boys/girls = 50.7%/59.4%), emotional symptoms (nervousness: boys/girls = 30.2%/51.0%; irritability: boys/girls = 23.6%/34.8%; sadness: boys/girls = 21.4%/39.7%), sleep/arousal-related symptoms (trouble falling asleep: boys/girls = 39.5%/49.4%; sleeping less than usual: boys/girls = 36.2%/43.4%; and fatigue: boys/girls = 29.8%/36.4%), and headaches (boys/girls = 27.6%/39.0%) during preseason baseline testing. The most central symptoms included dizziness, which was related to multiple somatic symptoms, and increased emotionality, which was related to a cluster of emotional symptoms. Girls reported symptoms at a greater frequency than boys, and there was evidence for variance in the global strength of the symptom network across gender, but not specific intersymptom relationships.

CONCLUSION

In the absence of injury, symptoms that commonly occur after concussion interact and potentially reinforce each other among student athletes with ADHD at preseason. Symptoms common in ADHD (i.e., difficulty concentrating) are not necessarily the most central within the symptom network. These findings may inform more precise interventions for athletes with ADHD and prolonged recovery following concussion.

Preliminary Validation of an Abbreviated Acute Concussion Symptom Checklist Using Item Response Theory

BACKGROUND

Symptom assessment is a critical component of concussion diagnosis and management, with item selection primarily driven by clinical judgment or expert consensus. We recently demonstrated that concussion symptoms assessed by the Sport Concussion Assessment Tool (SCAT) are essentially unidimensional, implying that overall symptom severity may be accurately estimated with relatively few questions. Briefer, evidence-based forms for symptom assessment would provide clinicians flexibility.

PURPOSE

To develop and validate an abbreviated assessment of general concussion symptom severity using item response theory analyses.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Broad clinical assessments (SCAT3, Immediate Post-concussion and Cognitive Testing, Balance Error Scoring System, and Brief Symptom Inventory-18 Global Severity Index) were completed by 265 injured athletes and 235 matched teammate controls at 24 to 48 hours and 8, 15, and 45 days after concussion. Symptom checklist short forms (3-14 items from the original 22) were selected using item response theory item information curves. Internal consistency reliability (Cronbach alpha), correlation with criterion measures assessed concurrently (ie, acute neurocognitive performance, balance, and emotional symptoms), predictive validity (correlations with symptom duration), and differences between concussed and control groups (Cohen d) were examined across forms. Sensitivity and false-positive rates of the forms were estimated and compared using reliable change indices derived from controls.

RESULTS

Across the 3- to 22-item forms, internal consistency was excellent (Cronbach alphas, 0.90-0.94). Clinical correlations were significant (P≤ .017) and to similar degrees for all short forms. Group difference confidence intervals overlapped across forms at 24- to 48-hour (Cohen d, 1.27-1.51) and 8-day follow-up (Cohen d, 0.31-0.44). Sensitivity remained similar across short forms, with a low false-positive rate in controls.

CONCLUSION

Our findings suggest that even an ultrashort (3-item) inventory provides sufficiently reliable and valid estimates of overall concussion symptom severity 24 to 48 hours after injury. Future revisions of the SCAT could eliminate inefficient items, although replication in larger samples and extension to other postinjury time points are warranted.

Systemic inflammation moderates the association of prior concussion with hippocampal volume and episodic memory in high school and collegiate athletes

BACKGROUND

There is a need to determine why prior concussion has been associated with adverse outcomes in some retired and active athletes. We examined whether serum inflammatory markers moderate the associations of prior concussion with hippocampal volumes and neurobehavioral functioning in active high school and collegiate athletes.

METHODS

Athletes (N = 201) completed pre-season clinical testing and serum collection (C-reactive protein [CRP]; Interleukin-6 [IL]-6; IL-1 receptor antagonist [RA]) and in-season neuroimaging. Linear mixed-effects models examined associations of prior concussion with inflammatory markers, self-reported symptoms, neurocognitive function, and hippocampal volumes. Models examined whether inflammatory markers moderated associations of concussion history and hippocampal volume and/or clinical measures.

RESULTS

Concussion history was significantly associated with higher symptom severity, p = 0.012, but not hippocampal volume or inflammatory markers (ps > 0.05). A significant interaction of prior concussion and CRP was observed for hippocampal volume, p = 0.006. Follow-up analyses showed that at high levels of CRP, athletes with two or more prior concussions had smaller hippocampal volume compared to athletes without prior concussion, p = 0.008. There was a significant interaction between prior concussion and levels of IL-1RA on memory scores, p = 0.044, i.e., at low levels of IL-1RA, athletes with two or more concussions had worse memory performance than those without prior concussion (p = 0.014).

CONCLUSION

Findings suggest that certain markers of systemic inflammation moderate the association between prior concussion and hippocampal volume and episodic memory performance. Current findings highlight potential markers for predicting at-risk individuals and identify therapeutic targets for mitigating the long-term adverse consequences of cumulative concussion.

Increased sensitivity to traumatic axonal injury on postconcussion diffusion tensor imaging scans in National Football League players by using premorbid baseline scans

OBJECTIVE

Statistical challenges exist when using diffusion tensor imaging (DTI) to assess traumatic axonal injury (TAI) in individual concussed athletes. The authors examined active professional American football players over a 6-year time period to study potential TAI after concussion and assess optimal methods to analyze DTI at the individual level.

METHODS

Active American professional football players recruited prospectively were assessed with DTI, conventional MRI, and standard clinical workup. Subjects underwent an optional preseason baseline scan and were asked to undergo a scan within 5 days of concussion during gameplay. DTI from 25 age- and sex-matched controls were obtained. Both semiautomated region-of-interest analysis and fully automated tract-based spatial statistics (TBSS) were used to examine DTI at individual and group levels. Statistical differences were assessed comparing individual DTI data to baseline imaging versus a normative database. Group-level comparisons were also performed to determine if longer exposure to professional-level play or prior concussion cause white matter microstructural integrity changes.

RESULTS

Forty-nine active professional football players were recruited into the study. Of the 49 players, 7 were assessed at baseline during the preseason and after acute concussion. An additional 18 players were assessed after acute concussion only. An additional 24 players had only preseason baseline assessments. The results suggest DTI is more sensitive to suspected TAI than conventional MRI, given that 4 players demonstrated decreased fractional anisotropy (FA) in multiple tracts despite normal conventional MRI. Furthermore, the data suggest individual assessment of DTI data using baseline premorbid imaging is more sensitive than typical methods of comparing data to a normative control group. Among all subjects with baseline data, 1 reduced FA tract (± 2.5 standard deviations) was found using the typical normative database reference versus 10 statistically significant (p < 0.05) reduced FA tracts when referencing internal control baseline data. All group-level comparisons were statistically insignificant (p > 0.05).

CONCLUSIONS

Baseline premorbid DTI data for individual DTI analysis provides increased statistical sensitivity. Specificity using baseline imaging also increases because numerous potential etiologies for reduced FA may exist prior to a concussion. These data suggest that there is a high potential for false-positive and false-negative assessment of DTI data using typical methods of comparing an individual to normative groups given the variability of FA values in the normal population.

Mental Health in the Young Athlete

PURPOSE OF REVIEW

The goal of the present paper is to provide a comprehensive overview of mental health concerns in young athletes, with a focus on common disorders, as well as population-specific risk factors.

RECENT FINDINGS

Athletes experience similar mental health concerns as non-athlete peers, such as anxiety, depression and suicidal ideation, ADHD, eating disorders, and substance abuse. However, they also experience unique stressors that put them at risk for the development or exacerbation of mental health disorders. Student athletes have to balance academics with rigorous training regimens while focusing on optimal performance and managing high expectations. Physical injuries, overtraining, concussion, sleep disorders, and social identity are some of the factors that also impact the mental health of student athletes. Existing literature highlights the need to develop proactive mental health and wellness education for young athletes, and to develop services that recognize the unique needs of this population.

Technology-enhanced visual desensitization home exercise program for post-concussive visually induced dizziness: a case series

Purpose: Post-concussive visually induced dizziness (VID), in which symptoms are provoked by exposure to complex visual motion, is associated with protracted recovery. Although vestibular rehabilitation therapy (VRT) is recommended to treat post-concussive dizziness, there is sparse literature reporting on specific VRT interventions treating VID. Methods: A consecutive series of 26 individuals referred for VRT post-concussion were retrospectively assessed for inclusion in this case series. Each participant underwent a combination of conventional VRT and a technology-enhanced visual desensitization home exercise program (HEP). Self-report and objective measures were recorded from initial and discharge therapy evaluations. Twenty-three individuals (mean age 23.1 ± 12.4) with post-concussive dizziness (mean 109 ± 56 days post-injury) and no evidence for peripheral vestibular dysfunction were included. Treatment duration averaged 6.9 ± 2.5 weeks. Results: There were significant improvements in post-intervention on subjective and objective measures of dizziness and gait (p < .05). The response to intervention was independent of pre-injury migraine history but pre-injury depression/anxiety increased self-report of post-treatment anxiety. Concurrent treatment with medications did not influence response to treatment. Conclusions: The combination therapy intervention improved outcome measures consistent with VRT treatment outcomes in both concussion and non-traumatic vestibular conditions. Individuals referred for VRT post-concussion warrant assessment for VID and may benefit from the addition of technology-enhanced visual desensitization.

SCAT5 vs. SCAT3 Symptom Reporting Differences and Convergent Validity in Collegiate Athletes

OBJECTIVE

The Sport Concussion Assessment Tool (SCAT), fifth Edition, Symptom Evaluation (S5SE) differs from previous versions by having examinees report trait (i.e. "typical" feelings) as opposed to state (i.e., "how you feel right now") concussion-like symptoms at baseline. This study assessed differences among, and convergent validity of, scores on the S5SE, SCAT3 Symptom Evaluation (S3SE), and the Brief Symptom Inventory (BSI-18).

METHODS

A total of 113 University of Florida varsity athletes completed symptom questionnaires on the same day in a counterbalanced administration. The final sample consisted of 94 participants (mean age ± SD = 18.4 ± 0.8 years, 57% male, 65% white) from 17 sports. We assessed convergent validity using Spearman rank-order correlations. Within-participant differences were analyzed with Wilcoxon Signed-Rank tests. We qualitatively described free-response answers to the S5SE question that asks, "if not feeling 100%, why?".

RESULTS

S5SE total severity score demonstrated adequate convergent validity with both the S3SE (rho = .407, p < .001) and BSI-18 (rho = .432, p < .001). Domain-specific analyses indicated variable convergent validity (rho < 0.4 to rho > 0.6). Severity scores did not differ between the S3SE and S5SE (p = .500), but 24.5% of participants reported S3SE > S5SE and 34.0% S5SE > S3SE. Three themes emerged from qualitative examination of reasons for "not feeling 100%": (1) tiredness/sleep, (2) adjustment difficulties, and (3) academic/athletic stress.

CONCLUSIONS

Adequate convergent validity exists between SCAT5 and SCAT3 symptom severity in collegiate athletes. However, most examinees report different baseline symptom severity when asked to describe their trait (S5SE) versus state symptoms (S3SE). Clinicians should consider using the new SCAT5 Symptom Evaluation as a screening tool for identifying otherwise healthy or "undiagnosed" individuals who would benefit from targeted interventions.

The relationship between fluid biomarkers and clinical outcomes in sports-related concussions: a systematic review

OBJECTIVES

The literature on fluid biomarkers for concussion has primarily focused on comparing athletes with and without a diagnosis of concussion and on examining the relationship between fluid biomarkers and exposure to head trauma. This systematic literature review aims to examine the strength of evidence for fluid biomarkers to be associated with clinically relevant outcomes in sports-related concussion.

METHODS

A systematic literature review was conducted using EmBASE, PubMed, and CINAHL. English-language articles that included athletes participating in organized sports and reported the relationship between at least one fluid biomarker and at least one clinical outcome measure, or provided data that could be used to analyze this relationship, were included.

RESULTS

Studies of the relationship between fluid biomarkers and clinical outcomes of concussion have yielded small or variable effects. There were significant inconsistencies in methodology including duration of time post-injury of biomarker collection, use of control groups, the number of time points post-injury that biomarkers were collected, and what clinical outcomes were utilized.

CONCLUSION

There is currently insufficient evidence to support a relationship between any of the included fluid biomarkers and clinical outcome measures of concussion. Future research including clinical outcome measures and using standardized study design and methodology is necessary.

Beyond Binary: Influence of Sex and Gender on Outcome after Traumatic Brain Injury

Traumatic brain injury (TBI) affects millions of individuals each year and is a leading cause of death and disability worldwide. TBI is heterogeneous and outcome is influenced by a combination of factors that include injury location, severity, genetics, and environmental factors. More recently, sex as a biological variable has been incorporated into TBI research, although there is conflicting literature regarding clinical outcomes in males versus females after TBI. We review the current clinical literature investigating sex differences after TBI. We focus our discussion on differences within contemporary gender categories to suggest that binary categories of male and female are not sufficient to guide clinical decisions for neurotrauma. Some studies have considered physiological variables that influence sex such as hormone cycles and stages in males and females pre- and post-TBI. These data suggest that there are phasic differences within male populations and within female populations that influence an individual's outcome after TBI. Finally, we discuss the impact of gender identity and expression on outcome after TBI and highlight the lack of neurotrauma research that includes non-binary individuals. Social constructs regarding gender impact an individual's vulnerability to violence and consequent TBI, including the successful reintegration to society after TBI. We call for incorporation of gender beyond the binary in TBI education, research, and clinical care. Precision medicine necessarily must progress beyond the binary to treat individuals after TBI.

Attention-Deficit/Hyperactivity Disorder and Outcome After Concussion: A Systematic Review

OBJECTIVE

To synthesize the literature and conduct a gap analysis on the association between attention-deficit/hyperactivity disorder (ADHD) and clinical outcome from sport-related concussion.

METHOD

The electronic search for this systematic review (PROSPERO ID: CRD42019128281) was conducted in February 2019 using terms related to concussion, sports/athletics, and predictors/modifiers of outcome to search the PubMed, PsycINFO, MEDLINE, CINAHL, Cochrane Library, EMBASE, SPORTDiscus, Scopus, and Web of Science databases. Eligible studies evaluated the association between ADHD and outcome from sport-related concussion. Of 4014 studies screened, 359 full-text articles were reviewed, with 14 studies ultimately included, involving 3623 participants (n = 359 [9.9%] with ADHD).

RESULTS

Study samples were primarily from specialty medical clinics (57.1%) and high school or college athletic groups (28.6%). Only 2 studies reported a statistically significant association between ADHD and worse clinical outcome. Of these, 1 included 13 participants with ADHD and the other included only 8 participants with ADHD. Only 1 previous study in this review was designed specifically to examine ADHD and prolonged concussion recovery, and that study did not report a statistically significant association.

CONCLUSION

There is not a clear association between ADHD and worse clinical outcome from concussion. However, eligible studies had limitations in research design, and nearly all studies were underpowered and evaluated the association between ADHD and concussion outcome as a secondary focus rather than the primary research question, precluding definitive conclusions. The association between ADHD and clinical outcomes remains unclear, and future research specifically examining ADHD and concussion recovery is needed.

A preliminary cross-sectional assessment of postural control responses to continuous platform rotations following a sport-related concussion

BACKGROUND

Individuals suffering a sport-related concussion typically recover within 1 month; however, persistent post-concussive symptoms are known to occur beyond this period. Clinical guidelines may not be sufficient to determine if dynamic postural control is still impaired at the point of the return to play decision.

RESEARCH QUESTION

Do individuals with a previous sport-related concussion who have returned to play show differences in postural control compared to individuals without a previous concussion, in response to continuous platform perturbations?

METHODS

Eight previously concussed and eight age- and position-matched participants completed six one-minute trials (three with eyes open/closed) whilst stood on a moving platform that rotated about the pitch axis with a peak-to-peak amplitude of 4° at a frequency of 0.8 Hz. Six trials were also captured during static quiet stance for comparison. Reactive and anticipatory stages of postural control were analysed by determining anteroposterior margins of stability (MoS) as a measure of whole-body postural control and head-to-trunk anchoring index as an indication of the head-trunk segmental coupling strategy.

RESULTS

Posterior MoS during platform rotations reduced for both groups during eyes closed trials, but previously concussed participants exhibited a significantly greater reduction (1.97 cm) in comparison to matched-controls (0.34 cm). Participants, regardless of group, showed a preference towards a head-stabilised-to-trunk strategy during platform rotations. There were no differences during static trials.

SIGNIFICANCE

This preliminary study suggests previously concussed athletes demonstrate a greater reduction in postural control whilst undergoing continuous platform rotations with eyes closed, which could indicate possible lingering deficits to other sensory systems such as the vestibular system, though participants were not likely to lose their balance.

Bifactor Model of the Sport Concussion Assessment Tool Symptom Checklist: Replication and Invariance Across Time in the CARE Consortium Sample

BACKGROUND

Identifying separate dimensions of concussion symptoms may inform a precision medicine approach to treatment. It was previously reported that a bifactor model identified distinct acute postconcussion symptom dimensions.

PURPOSE

To replicate previous findings of a bifactor structure of concussion symptoms in the Concussion Assessment Research and Education (CARE) Consortium sample, examine measurement invariance from pre- to postinjury, and evaluate whether factors are associated with other clinical and biomarker measures.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 2.

METHODS

Collegiate athletes were prospectively evaluated using the Sport Concussion Assessment Tool-3 (SCAT-3) during preseason (N = 31,557); 2789 were followed at <6 hours and 24 to 48 hours after concussion. Item-level SCAT-3 ratings were analyzed using exploratory and confirmatory factor analyses. Bifactor and higher-order models were compared for their fit and interpretability. Measurement invariance tested the stability of the identified factor structure across time. The association between factors and criterion measures (clinical and blood-based markers of concussion severity, symptom duration) was evaluated.

RESULTS

The optimal structure for each time point was a 7-factor bifactor model: a General factor, on which all items loaded, and 6 specific factors-Vestibulo-ocular, Headache, Sensory, Fatigue, Cognitive, and Emotional. The model manifested strict invariance across the 2 postinjury time points but only configural invariance from baseline to postinjury. From <6 to 24-48 hours, some dimensions increased in severity (Sensory, Fatigue, Emotional), while others decreased (General, Headache, Vestibulo-ocular). The factors correlated with differing clinical and biomarker criterion measures and showed differing patterns of association with symptom duration at different time points.

CONCLUSION

Bifactor modeling supported the predominant unidimensionality of concussion symptoms while revealing multidimensional properties, including a large dominant General factor and 6 independent factors: Headache, Vestibulo-ocular, Sensory, Cognitive, Fatigue, and Emotional. Unlike the widely used SCAT-3 symptom severity score, which declines gradually after injury, the bifactor model revealed separable symptom dimensions that have distinct trajectories in the acute postinjury period and different patterns of association with other markers of injury severity and outcome.

CLINICAL RELEVANCE

The SCAT-3 total score remains a valuable, robust index of overall concussion symptom severity, and the specific factors identified may inform management strategies. Because some symptom dimensions continue to worsen in the first 24 to 48 hours after injury (ie, Sensory, Fatigue, Emotional), routine follow-up in this time frame may be valuable to ensure that symptoms are managed effectively.

Reliability of Objective Eye-Tracking Measures Among Healthy Adolescent Athletes

OBJECTIVE

To determine the test-retest correlation of an objective eye-tracking device among uninjured youth athletes.

DESIGN

Repeated-measures study.

SETTING

Sports-medicine clinic.

PARTICIPANTS

Healthy youth athletes (mean age = 14.6 ± 2.2 years; 39% women) completed a brief, automated, and objective eye-tracking assessment.

INDEPENDENT VARIABLES

Participants completed the eye-tracking assessment at 2 different testing sessions.

MAIN OUTCOME MEASURES

During the assessment, participants watched a 220-second video clip while it moved around a computer monitor in a clockwise direction as an eye tracker recorded eye movements. We obtained 13 eye movement outcome variables and assessed correlations between the assessments made at the 2 time points using Spearman's Rho (rs).

RESULTS

Thirty-one participants completed the eye-tracking evaluation at 2 time points [median = 7 (interquartile range = 6-9) days between tests]. No significant differences in outcomes were found between the 2 testing times. Several eye movement variables demonstrated moderate to moderately high test-retest reliability. Combined eye conjugacy metric (BOX score, rs = 0.529, P = 0.008), the variance of the ratio for both eye movements in the horizontal (rs = 0.497, P = 0.013) and vertical (rs = 0.446; P = 0.029) movement planes along the top/bottom of the computer screen, and the variance of the left and right eye movement along the bottom segment of the computer screen (rs = 0.565; P = 0.004) each demonstrated moderate between-test correlations.

CONCLUSIONS

Automated and quantitative eye movement and conjugacy metrics provide relatively stable measurements among a group of healthy youth athletes. Thus, their inclusion as a visual tracking metric may be complementary to other visual examination techniques when monitoring concussion recovery across time.

Neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome

BACKGROUND

Persistent Sport-Related Post-Concussion Syndrome is often diagnosed with any type of prolonged PCS symptoms. However, there are not specific diagnostic criteria for PPCS such that misdiagnosis often occurs. Further, the signs and symptoms of PCS overlap with other common illnesses such as depression, anxiety, migraines, ADHD and others. Misdiagnosis may lead to less than efficacious treatment, resulting in prolonged symptoms.

OBJECTIVE

This article will review relevant evidence-based literature on PCS, pointing out the lack of a systemic diagnostic framework. It will also provide evidence that highlights the multiple conflicting findings in the literature. This article will posit the BioPsychoSocial framework as the best diagnostic framework for understanding the impact of concussions on the person and to generate individualized and personal interventions.

METHODS

A narrative review of sport concussion-related articles was conducted, after extensive searches of relevant and non-relevant literature by each author, as well as articles recommended by colleagues. Articles varied from American Academy of Neurology Class I to IV for evaluation and critique. Class IV articles were reviewed, as there is much public misconception regarding sport and other concussion treatment that needed identification and discussion.

RESULTS

Articles reviewed varied by quality of research design and methodology. Multiple symptoms, recovery patterns and rehabilitation treatment approaches are purported in the sport-related concussion literature. Current consensus data as well as the mixed and contradictory findings were explored.

CONCLUSIONS

Persistent Sport-Related Post-Concussion Syndrome is a topic of great interest to both professionals and the general public. There is much misunderstanding about the etiology, causation, diagnostic formulations, symptom presentation, prolonging factors and treatment involved in this syndrome. This article posits an individualized multi-system diagnostic formulation, examining all relevant factors, as generating the best interventions for neurorehabilitation of Persistent Sport-Related Post-Concussion Syndrome.

Development and description of SAAM intervention: A brief, multidimensional and psycho-educational intervention for adults with mild traumatic brain injury

BACKGROUND

Mild traumatic brain injury (mTBI) is associated with persistent post-concussive symptoms (PCSs) in approximately 15% of cases. These symptoms can be somatic (e.g., headache), cognitive (e.g., forgetfulness, poor attention and concentration capacities), emotional (e.g., anxiety, depression, irritability) and/or sleep-arousal complaints (e.g., fatigue, sleep problems). Although practice guidelines recommend early intervention to prevent and treat PCS, we still lack an effective, standardized, integrative, post-acute intervention based on a sound and validated theoretical model.

OBJECTIVES

The purpose of this article is to present the development and theoretical background underpinning a novel intervention for patients with PCSs in the post-acute phase after mTBI (1-3 months post-injury).

PROCEDURE

With a biopsychosocial approach (Hou et al., 2012) and best practice recommendations, we developed a novel multidimensional intervention targeting factors that perpetuate PCSs and that can be changed with the intervention. This individual-session intervention provides practical tools for managing PCSs and is designed to provide psycho-education and reassurance, reinforce individual objectives and promote a return to activities. Each session targets one category of PCSs: Sleep/fatigue, Attention, Anxiety/depressed mood, Memory/Organization (SAAM intervention). The rationale underlying the choices of format and content for the intervention is discussed, as are the associated strengths, limitations, opportunities and challenges.

CONCLUSION

This article could support researchers and clinicians to develop, replicate and/or implement interventions addressing current best practices in mTBI management.

Management and Treatment of Concussions via Tele-Concussion in a Pediatric Setting: Methodological Approach and Descriptive Analysis

BACKGROUND

Approximately 2 million children in the United States sustain a concussion annually, resulting in an economic impact as high as US $20 billion. Patients who receive treatment at concussion specialty clinics, versus primary care, experience faster recovery, thereby reducing patient burden and subsequent medical-related costs. Accessibility to specialty clinics is typically limited by the availability of in-office visits. This is particularly relevant in light of the severe acute respiratory syndrome coronavirus 2 pandemic and subsequent guidance to eliminate all non-medically necessary in-clinic visits. Telehealth has been used to effectively deliver in-clinic care across several disciplines including psychiatry, psychology, and neuropsychology. However, a model of telehealth delivered concussion assessment, treatment, and management has not been established.

OBJECTIVE

The purposes of this paper are to describe a pediatric concussion specialty clinic's experiences in delivering telehealth concussion services and to provide preliminary descriptive data on a sample of pediatric telehealth patients with concussions.

METHODS

The specialty pediatric concussion clinic described here began providing telehealth services in 2019 and is part of the largest and fastest-growing telehealth hospital network in the United States. The clinical care process will be described, including accessing the telehealth platform, assessment during the initial appointment, injury management including communication with relevant patient stakeholders (eg, parent or guardians, athletic trainers), dissemination of rehabilitation exercises, and nature of follow-up visits. Descriptive data will include patient demographics, the radius of care, the time between the date of injury and initial visit, the average number of follow-up visits, and days until medically cleared for return-to-learn and return-to-play.

RESULTS

The analytic sample included 18 patients with concussions who were seen for all of their visits via telehealth between August 2019 and April 2020. The mean age of the sample was 14.5 (SD 2.5) years. The radius of care was a median of 17 (IQR 11.0-31.0) miles from the clinic with a median time between injury and the first visit of 21 (IQR 6.0-41.5) days. The mean number of visits was 2.2 (SD 0.8) with a median days between visits of 5.4 (IQR 3.0-9.3) to manage and treat the concussion. Of the 18 patients, 55.6% (n=10) were medically cleared for return-to-learn or -play in a median of 15.5 (IQR 11.0-29.0) days.

CONCLUSIONS

Limited access to health care is a well-understood barrier for receiving quality care. Subsequently, there are increasing demands for flexibility in delivering concussion services remotely and in-clinic. This is the first paper to provide a clinically relevant framework for the assessment, management, and treatment of acute concussion via telehealth in a pediatric population.

Comparison of the PHQ9 and ImPACT symptom cluster scores in measuring depression among college athletes

Accurate identification of athletes in need of mental health services is essential. The clinical utility of the Patient Health Questionnaire - 9 (PHQ-9), a stand-alone measure of depression, was explored among Division II college athletes (n = 1,209) completing pre-participation concussion baseline assessments (mean age = 19.28), which also included Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). ImPACT's symptom inventory can be divided into four clusters: affective, cognitive, physical/somatic, and sleep. Most athletes (81.9%) did not endorse any items on the affective symptom cluster; however, 90 athletes (7.4%) fell above the cutoff of 5 for depression on the PHQ-9, and approximately half of all athletes endorsed one or more PHQ-9 items. Simple linear regressions revealed ImPACT's sleep symptom cluster as the best predictor of PHQ-9 total score; however, affective, cognitive, and physical symptom clusters significantly predicted PHQ-9 total score as well. Due to relative under-endorsement of items on ImPACT's affective symptom cluster compared to the PHQ-9, the clinical utility of incorporating a stand-alone measure of depression such as the PHQ-9 during baseline testing is supported.

The Prospective Study of Epigenetic Regulatory Profiles in Sport and Exercise Monitored Through Chromosome Conformation Signatures

The integration of genetic and environmental factors that regulate the gene expression patterns associated with exercise adaptation is mediated by epigenetic mechanisms. The organisation of the human genome within three-dimensional space, known as chromosome conformation, has recently been shown as a dynamic epigenetic regulator of gene expression, facilitating the interaction of distal genomic regions due to tight and regulated packaging of chromosomes in the cell nucleus. Technological advances in the study of chromosome conformation mean a new class of biomarker-the chromosome conformation signature (CCS)-can identify chromosomal interactions across several genomic loci as a collective marker of an epigenomic state. Investigative use of CCSs in biological and medical research shows promise in identifying the likelihood that a disease state is present or absent, as well as an ability to prospectively stratify individuals according to their likely response to medical intervention. The association of CCSs with gene expression patterns suggests that there are likely to be CCSs that respond, or regulate the response, to exercise and related stimuli. The present review provides a contextual background to CCS research and a theoretical framework discussing the potential uses of this novel epigenomic biomarker within sport and exercise science and medicine.

Quality of life of ice hockey players after retirement due to concussions

Background:

Sports-related concussion (SRC) is increasingly recognized as a potential health problem in ice hockey. Quality of life (QoL) in players retiring due to SRC has not been thoroughly addressed.

Materials & methods:

QoL using the Sports Concussion Assessment Tool 5th Edition, Impact of Event Scale-Revised and Short Form Health Survey was measured in Swedish ice hockey players who retired due to persistence of postconcussion symptoms or fear of attaining additional SRC.

Results:

A total of 76 players were assessed, on average of 5 years after their most recent SRC. Overall, retired players had a high burden of postconcussion symptoms and reduced QoL.

Conclusion:

Retired concussed ice hockey players have a reduced QoL, particularly those retiring due to postconcussion symptoms. Symptom burden should be continuously evaluated and guide the decision to retire.

Concussions sustained while playing ice hockey are increasingly recognized as a potential health problem. Long-term consequences for players retiring due to concussions have not been fully investigated. Therefore, we evaluated symptoms, quality of life and post-traumatic stress in former Swedish ice hockey players who retired due to postconcussion symptoms or to a fear of attaining additional concussions. We found that retired ice hockey players with a history of concussions had a low quality of life and high post-traumatic stress, particularly in players with a high symptom burden. We recommend that symptom burden should be continuously evaluated and guide the decision to retire.

The relationship between depressive symptoms, somatic complaints, and concussion history with poor sleep in collegiate athletes

OBJECTIVE

Ongoing exploration of factors related to poor sleep in collegiate athletes is important as understanding of the risks and consequences of poor sleep in this specific population increases.

DESIGN

Retrospective cohort study.

SETTING

University in the Pacific Northwest.

PARTICIPANTS

One-hundred thirty-seven male and female collegiate athletes across 5 collision, contact, and limited contact team sports.

MEASUREMENTS

Depressive symptoms (Patient Health Questionnaire 9; PHQ-9), anxiety symptoms (General Anxiety Disorder 7; GAD-7), and somatic complaints (Patient Health Questionnaire 15; PHQ-15). Sleep quality (Pittsburgh Sleep Quality Index; PSQI) used both a cutoff score ≥6 and a cutoff score of ≥8, indicating "poor sleep quality" to reduce threats to divergent validity.

RESULTS

Poor sleep quality as defined by PSQI ≥ 6 was present in 53% of athletes, and as defined by PSQI ≥ 8 was identified in 33.5% of the cohort. There were no differences in the incidence of poor sleepers between sport, race/ethnicity, or sex. Multiple regression analysis revealed that depressive symptoms, somatic complaints, Caucasian race, male sex, and number of concussions were significant predictors of poor sleep (P < .05). The model accounted for 43% of the variance in PSQI and primarily by depressive symptoms explaining 9% of reported sleep quality variability. Anxiety symptoms, sport category, and history of migraines were not significant predictors of poor sleep quality.

CONCLUSIONS

A high incidence of poor sleep among collegiate athletes was observed regardless of sport, and may be related to depressive symptoms, somatic complaints, Caucasian race, male sex, and historical number of concussions.

Characteristics of Concussion in Elementary School-Aged Children: Implications for Clinical Management

OBJECTIVE

To comprehensively characterize the clinical presentation and course of care for concussion among 5- to 11-year-old children, identifying preinjury and injury factors potentially influencing clinical outcomes.

STUDY DESIGN

A single-institution retrospective cohort study using electronic health record data from children ages 5- to 11 years with a concussion from July 1, 2014, through June 30, 2015. Electronic health record data were abstracted for a 20% random sample of 292 patients.

RESULTS

Three-fourths of patients (74.3%) presenting for concussion care had a standardized visiovestibular assessment performed. Almost all of those who eventually sought specialty care (92.9%) also had such an assessment, and only 42.9% patients initially seen in the emergency department or urgent care were examined in this manner. Of those assessed, 62.7% (n = 136) demonstrated deficits, with children ages 9-11 years more frequently exhibiting deficits than their younger counterparts (67.9% vs 53.2%; P = .03). Almost all patients (95.9%) reported at least 1 somatic symptom (eg, headache, dizziness), and one-half to two-thirds reported problems with sleep (54.1%) and visiovestibular symptoms (66.1%). Only 11.6% of children were referred for rehabilitation therapies and less than one-half of concussed patients (43.8%) were provided with a letter recommending school accommodations.

CONCLUSIONS

Somatic symptoms, sleep problems, and visiovestibular deficits are common in elementary school-aged children with concussion, but specific visiovestibular clinical assessments are often not performed, particularly in the emergency department setting. Recommendations for school accommodations are often not provided at the time of concussion diagnosis. Incorporating a standardized visiovestibular assessment into practice could facilitate early targeted school accommodations and thereby improve return to learning for elementary school-aged children with concussion.

Factors Associated With Delayed Concussion Reporting by United States Service Academy Cadets

CONTEXT

Approximately half of individuals who sustain a concussion do not immediately report their injuries. Motivators for not reporting include thinking the suspected concussion was not a serious injury and wanting to continue participating in activity. Additionally, military personnel have concerns about how concussions may affect their careers. However, delayed reporting can prolong neurobehavioral recovery. Understanding the frequency of delayed reporting and contributing factors will aid in identifying individuals who may be more likely to delay reporting.

OBJECTIVE

To describe the frequency of delayed concussion reporting by service academy cadets and determine if sex, injury setting, sport level, or medical history is capable of predicting delayed reporting.

DESIGN

Cohort study.

SETTING

Service academies.

PATIENTS OR OTHER PARTICIPANTS

A total of 316 patients with concussions were observed from January 2014 to August 2016.

MAIN OUTCOME MEASURE(S)

All cadets completed an annual concussion baseline collection of demographic, medical history, and sports participation information. Delayed concussion reporting served as the outcome variable. Predictor variables were sex, injury setting, and sport level, as well as concussion, headache, and learning disorder history. Frequencies were calculated to describe the proportion of participants who delayed reporting. Univariable and multivariable logistic regression models were used to assess if the predictor variables were associated with delayed concussion reporting. Odds ratios (ORs) and 95% confidence intervals were calculated for all variables included in the final model.

RESULTS

Of the patients with concussion, 51% were classified as delayed reporting. In univariable models, females (OR = 1.70) and National Collegiate Athletic Association cadet-athletes (OR = 1.98) were more likely to delay reporting than males and intramural cadet-athletes, respectively. The multivariable model yielded similar findings.

CONCLUSIONS

Roughly half of the cadets who sustained a concussion failed to immediately report their injury. Specifically, our data suggested that female cadets, cadets injured outside of competition, and highly competitive cadet-athletes were almost twice as likely to delay reporting as others.

Assessing the predictive value of primary evaluation with the Immediate Post-Concussion Assessment and Cognitive Test following head injury

OBJECTIVE

Concussions are a major public health concern, especially for high school and college student athletes. However, there are few prognostic metrics that can accurately quantify concussion severity in order to anticipate recovery time and symptom regression. The Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) is a widely used neurocognitive assessment that can diagnose and track recovery from concussions. This study assesses whether initial ImPACT scores, collected within 48 hours of the injury, can predict persistence of concussion at follow-up.

METHODS

Results from 6912 ImPACT tests were compiled in 2161 unique student athletes, ages 12-22 years. The authors defined a novel metric, the Severity Index (SI), which is a summation of the number of standard deviations from baseline at the 80% CI for each of the 5 composite scores reported by ImPACT. Patients were binned into groups based on SI (0-3.99, 4-7.99, 8-11.99, 12+) and the relationships between SI groups, composite scores, symptom profiles, and recovery time were characterized using 1-way and 2-way ANOVAs and Kaplan-Meier plots. A logistic regression assessed the value of SI for predicting concussion at follow-up.

RESULTS

Patients with a higher SI at diagnosis were more likely to still be concussed at their first follow-up (F3,2300 = 93.06; p < 0.0001). Groups with a higher SI also displayed consistently slower recovery over a 42-day period and were more likely to report symptoms in all 4 symptom clusters (Migraine, Cognition, Sleep, and Neuropsychiatric). When controlling for sex, age, number of previous concussions, days between assessments, and location, SI significantly increased the odds of being concussed at follow-up (OR 1.122, 95% CI 1.088-1.142; p < 0.001). This model showed good discrimination with an area under the curve of 0.74.

CONCLUSIONS

SI is a useful prognostic tool for assessing head injury severity. Concussions with higher initial SI tend to last longer and have broader symptomatic profiles. These findings can help patients and providers estimate recovery based on similar ImPACT score profiles.

Association Between Concussion History and Factors Relating to Cognitive, Behavioral, and Emotional Health Among American High School Athletes: A Cross-sectional Analysis

BACKGROUND

The cognitive, behavioral, and emotional deficits that may be associated with sports-related concussions among adolescents are unclear.

PURPOSE

To examine the association between reported concussion history and factors relating to cognitive, behavioral, and emotional health among a population-based sample of US high school-aged adolescents.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Participants included a representative sample of US high school student-athletes who reported a concussion history (in the past 12 months) and relevant behaviors/outcomes within 3 domains: cognitive (academics, difficulty concentrating), behavioral (drinking and driving, carrying a weapon, physically fighting, tobacco use, marijuana use, binge drinking), and emotional (symptoms of depression, suicidal thoughts/actions). The adjusted relative odds of experiencing 0 and at least 1, 2, 3, or ≥4 concussions were modeled while mutually adjusting for the behaviors of interest in addition to age, race/ethnicity, and sleep problems. Data were reported in sex stratum.

RESULTS

A total of 13,268 participants were included in the unweighted data set. Overall, 14.5% (95% CI, 12.9%-16.2%) of female and 18.1% (95% CI, 16.4%-19.8%) of male student-athletes had at least 1 concussion in the past 12 months. As compared with those who reported not engaging in any of the behaviors deleterious to health or having had any of the negative health outcomes (composite score of 0), female athletes with composite scores of 1 to 4, 5 to 7, and 8 to 11 were 1.94 (95% CI, 1.55-2.43), 3.13 (95% CI, 2.30-4.33), and 6.05 (95% CI, 3.75-9.75) times more likely to have a recent history of concussions after accounting for relevant factors. As compared with those having a composite score of 0, male athletes with composite scores of 1 to 4, 5 to 7, and 8 to 11 were 2.03 (95% CI, 1.58-2.59), 3.80 (95% CI, 2.71-5.34), and 8.23 (95% CI, 4.91-13.77) times more likely to have a recent history of concussions after accounting for relevant factors.

CONCLUSION

Self-reported concussions among US high school athletes is related to several deleterious health behaviors and outcomes. These associations should be confirmed in longitudinal analyses.

Assessment of Long-Term Effects of Sports-Related Concussions: Biological Mechanisms and Exosomal Biomarkers

Concussion or mild traumatic brain injury (mTBI) in athletes can cause persistent symptoms, known as post-concussion syndrome (PCS), and repeated injuries may increase the long-term risk for an athlete to develop neurodegenerative diseases such as chronic traumatic encephalopathy (CTE), and Alzheimer's disease (AD). The Center for Disease Control estimates that up to 3.8 million sport-related mTBI are reported each year in the United States. Despite the magnitude of the phenomenon, there is a current lack of comprehensive prognostic indicators and research has shown that available monitoring tools are moderately sensitive to short-term concussion effects but less sensitive to long-term consequences. The overall aim of this review is to discuss novel, quantitative, and objective measurements that can predict long-term outcomes following repeated sports-related mTBIs. The specific objectives were (1) to provide an overview of the current clinical and biomechanical tools available to health practitioners to ensure recovery after mTBIs, (2) to synthesize potential biological mechanisms in animal models underlying the long-term adverse consequences of mTBIs, (3) to discuss the possible link between repeated mTBI and neurodegenerative diseases, and (4) to discuss the current knowledge about fluid biomarkers for mTBIs with a focus on novel exosomal biomarkers. The conclusions from this review are that current post-concussion clinical tests are not sufficiently sensitive to injury and do not accurately quantify post-concussion alterations associated with repeated mTBIs. In the current review, it is proposed that current practices should be amended to include a repeated symptom inventory, a cognitive assessment of executive function and impulse control, an instrumented assessment of balance, vestibulo-ocular assessments, and an improved panel of blood or exosome biomarkers.

Clinical predictors of post-injury anxiety in adolescent patients following concussion

The purpose of the current study was to examine predictors (e.g., pre-injury anxiety and sub-types, concussion symptom severity, neurocognitive performance, and vestibular/ocular-motor impairment) of post-injury anxiety scores following concussion among youth aged 10-18 years. This observational cohort study enrolled patients (n = 129) within 30 days of a diagnosed concussion. Patients completed Screening for Child Anxiety Related Disorders-Child Reports (SCARED-C), Generalized Anxiety Disorder-7 (GAD-7), Post-concussion Symptom Scale, neurocognitive testing, and Vestibular-Ocular Motor Screening. Logistic regression analyses were conducted to evaluate the role of risk factors and clinical outcomes as predictors of mild (GAD-7 > 5) and moderate levels (GAD-7 > 10) of post-injury anxiety. Twenty-two percent (n = 28) of patients reported clinical levels of pre-injury anxiety, and 13% (n = 17) reported clinical levels of post-injury anxiety. The logistic regression model predicting mild or greater anxiety was significant (R² = 31.7%; p < 0.001) and supported pre-injury panic symptoms (OR = 1.38) and total symptom severity (OR = 1.04) as the most robust predictors. The logistic regression model predicting clinical anxiety was significant (R² = 47.2%; p < 0.001) and supported non-SRC injury type (OR = 9.48), vestibular dysfunction (OR = 1.74) and pre-injury panic symptoms (OR = 1.57) as the most robust predictors. Results suggest that clinicians should employ measures of pre-injury and post-injury emotional functioning when evaluating and treating concussion among adolescents. Moreover, these results highlight the importance of assessing different types of pre-injury and post-injury anxiety in the context of concussion management.

Bigger Necks Are Not Enough: An Examination of Neck Circumference in Incoming College Athletes

Neck circumference is quick and simple to measure and thus an attractive proxy of neck strength, a putative mechanism underlying risk of sport-related concussion (SRC). Research, however, is limited on the relationship of neck circumference to SRC. Our study examined differences in neck circumference based on sex, concussion history, concussions experienced subsequent to college entry, and participation in sports with high versus low risk for contact. Neck circumference was measured in incoming NCAA Division I athletes (N = 324) from a large northeastern university during athlete pre-participation physicals. Sex, sport team, and self-reported concussion history were obtained from retrospective pre-participation questionnaires and medical chart review. Concussion diagnoses during college were collected subsequent to neck measurements from medical chart review. Proportional neck circumference (normalized by body mass index) was computed. Each sport was categorized as involving high or low risk of contact (as a proxy of risk for injury). Sex differences in neck circumference and proportional neck circumference were assessed. Differences in neck circumference and proportional neck circumference were also characterized by contact risk and SRC history (with biological sex included as a covariate). Differences in neck circumference and proportional neck circumference were explored among those who did versus did not experience subsequent SRC diagnosis. Males had significantly larger neck circumference and proportional neck circumference than females. Neck circumference and proportional neck circumference were not related to SRC history or subsequent SRC. Neck circumference is a quick and simple measure; however, even when considered in proportion to body mass, it was unrelated to SRC. Future studies are needed to assess whether this is due to a lack of relationship between the neck and injury or limitations in circumference as a proxy measure of cervical spine characteristics and biomechanics.

Concussion-Recovery Trajectories Among Tactical Athletes: Results From the CARE Consortium

CONTEXT

Assessments of the duration of concussion recovery have primarily been limited to sport-related concussions and male contact sports. Furthermore, whereas durations of symptoms and return-to-activity (RTA) protocols encompass total recovery, the trajectory of each duration has not been examined separately.

OBJECTIVE

To identify individual (eg, demographics, medical history), initial concussion injury (eg, symptoms), and external (eg, site) factors associated with symptom duration and RTA-protocol duration after concussion.

DESIGN

Cohort study.

SETTING

Three US military service academies.

PATIENTS OR OTHER PARTICIPANTS

A total of 10 604 cadets at participating US military service academies enrolled in the study and completed a baseline evaluation and up to 5 postinjury evaluations. A total of 726 cadets (451 men, 275 women) sustained concussions during the study period.

MAIN OUTCOME MEASURE(S)

Number of days from injury (1) until the participant became asymptomatic and (2) to complete the RTA protocol.

RESULTS

Varsity athlete cadets took less time than nonvarsity cadets to become asymptomatic (hazard ratio [HR] = 1.75, 95% confidence interval = 1.38, 2.23). Cadets who reported less symptom severity on the Sport Concussion Assessment Tool, third edition (SCAT3), within 48 hours of concussion had 1.45 to 3.77 times shorter symptom-recovery durations than those with more symptom severity. Similar to symptom duration, varsity status was associated with a shorter RTA-protocol duration (HR = 1.74, 95% confidence interval = 1.34, 2.25), and less symptom severity on the SCAT3 was associated with a shorter RTA-protocol duration (HR range = 1.31 to 1.47). The academy that the cadet attended was associated with the RTA-protocol duration (P < .05).

CONCLUSIONS

The initial total number of symptoms reported and varsity athlete status were strongly associated with symptom and RTA-protocol durations. These findings suggested that external (varsity status and academy) and injury (symptom burden) factors influenced the time until RTA.

Utilizing the Biopsychosocial Model in Concussion Treatment: Post-Traumatic Headache and beyond

PURPOSE OF REVIEW

To discuss recent literature concerning the application of the biopsychosocial model in the management of concussion and post-concussion headache.

RECENT FINDINGS

Current research suggests that the biopsychosocial model is applicable to the concussion management process, particularly management of post-concussion headache. Such application is best illustrated by current active treatment strategies such as exercise, multifaceted rehabilitation, and psychosocial interventions targeting improved patient outcomes. Overall, the biopsychosocial model has significant applications to the management of concussion, particularly post-concussion headache. Presentation and recovery following concussion and post-traumatic headache is multifaceted and includes the continuum of biological, psychological, and social considerations. In order to fully understand the widespread clinical utility and application of such models, there is a continued need for researcher, practitioner, and patient integration and collaboration to determine the most effective assessment and treatment strategies.

Eye Movements, Dizziness, and Mild Traumatic Brain Injury (mTBI): A Topical Review of Emerging Evidence and Screening Measures

BACKGROUND AND PURPOSE

Eye movements may be adversely affected after mild traumatic brain injury (mTBI) and should be examined. The purpose of this topical review is to provide the clinician with the most up-to-date knowledge related to eye movement abnormalities, screening measures, and evidence related to exercise interventions that are designed to enhance outcomes in persons after mTBI.

SUMMARY OF KEY POINTS

Presence of eye misalignment such as tropias or phoria or symptoms with head/eye movements such as vestibulo-ocular reflex (VOR) × 1, saccades, or smooth pursuits may slow the person's recovery. Tools such as the Convergence Insufficiency Symptom Survey, the Vestibular/Ocular Motor Screening, the Pediatric Vestibular Symptom Questionnaire, and the Pediatric Visually Induced Dizziness questionnaire may aid in identifying visual concerns to target in the physical therapy intervention program. There is emerging evidence that vestibular rehabilitation enhances recovery in persons after mTBI.

RECOMMENDATIONS FOR CLINICAL PRACTICE

A thorough eye examination is highly recommended after mTBI to identify targeted areas for intervention.

Recommendations for initial examination, differential diagnosis, and management of concussion and other head injuries in high-level football

Head injuries can result in substantially different outcomes, ranging from no detectable effect to transient functional impairments to life‐threatening structural lesions. In high‐level international football (soccer) tournaments, on average, one head injury occurs in every third match. Making the diagnosis and determining the severity of a head injury immediately on‐pitch or off‐field is a major challenge for team physicians, especially because clinical signs of a brain injury can develop over several minutes, hours, or even days after the injury. A standardized approach is useful to support team physicians in their decision whether the player should be allowed to continue to play or should be removed from play after head injury. A systematic, football‐specific procedure for examination and management during the first 72 hours after head injuries and a graduated Return‐to‐Football program for high‐level players have been developed by an international group of experts based on current national and international guidelines for the management of acute head injuries. The procedure includes seven stages from the initial on‐pitch examination to the graduated Return‐to‐Football program. Details of the assessments and the consequences of different outcomes are described for each stage. Criteria for emergency management (red flags), removal from play (orange flags), and referral to specialists for further diagnosis and treatment (persistent orange flags) are provided. The guidelines for return to sport after concussion‐type head injury are specified for football. Thus, the present paper presents a comprehensive procedure for team physicians after a head injury in high‐level football.

Prognosis for Persistent Post Concussion Symptoms using a Multifaceted Objective Gait and Balance Assessment Approach

BACKGROUND

Concussion prognosis is a challenging clinical task. Identification of measures useful for persistent symptom risk can help optimize treatment pathways and allow clinicians to offer appropriate anticipatory guidance.

RESEARCH QUESTION

Can a multifaceted single/dual-task postural control assessment within one week of a diagnosed concussion identify the odds of developing persistent post-concussion symptoms (PPCS; symptoms that persist for more than 28 days post-concussion)?

METHODS

We conducted a prospective cohort study of youth and young adult athletes who were evaluated within 7 days of injury, and followed until they no longer reported concussion symptoms. Participants were grouped into those who developed PPCS and those who did not. During the initial evaluation, participants completed a postural control evaluation in single/dual-task conditions. We calculated six gait performance variables (in single/dual-task conditions), nine quiet stance performance variables, and three cognitive task performance (standing and walking) variables. We conducted between-group comparisons to identify candidate PPCS prognostic variables, and multivariable models to adjust for covariates (age, post-injury evaluation time, history of concussion, and BMI).

RESULTS

Sixty-six participants completed the study: 24% reported PPCS (mean age = 16.9 ± 3.5 years; 50% female; evaluated 4.2 ± 1.9 days post-injury) and 74% (mean age = 18.3 ± 3.0 years; 52% female; evaluated 3.5 ± 1.6 days post-injury) did not. Between-group comparisons indicated greater dual-task transverse plane center-of-mass (COM) range of motion (ROM) (13.1 ± 4.3 vs. 9.9 ± 2.5 degrees; p = 0.013) and lateral step variability (5.1 ± 1.4 vs. 4.0 ± 1.2 cm; p = 0.003) for the PPCS group relative to the no PPCS group. After multivariable modeling, dual-task transverse plane COM ROM (adjusted odds ratio = 1.34, 95% CI = 1.07, 1.68) and lateral step variability (adjusted odds ratio = 1.85, 95% CI = 1.13, 3.05) were significantly associated with PPCS.

SIGNIFICANCE

Dual-task transverse plane movement and lateral step variability demonstrate viable prognostic ability for PPCS among youth and young adult athletes and, along with other established factors, may add incremental value to PPCS prognosis models.