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Context: There is a well-established increased risk of lower-extremity (LE) musculoskeletal (MSK) injury following a sport-related concussion (SRC). Neuromuscular training programs improve biomechanics associated with LE MSK injury and reduce LE MSK injury incidence, but their relative effectiveness in athletes with history of SRC is unknown. The purpose of this study was to evaluate LE MSK injury incidence in female adolescent athletes with history of SRC following a neuromuscular training intervention. Design: Prospective case-control. Methods: Seventy-seven adolescent female athletes aged 12–18 years who participated in soccer, volleyball, or basketball were recruited from a single institutional sports medicine research and performance center to complete a 6-week neuromuscular training program prior to competitive athletic season. Group (Control, History of SRC) comparisons of athlete exposure and relative LE MSK injury risk and rates during the competitive athletic season were assessed. Results: Ten injuries were recorded by 9 athletes. Female athletes who reported history of SRC had increased injury risk (Risk Ratio 3.9, 95% CI, 1.1–13.8, P =.01) and increased injury rate (rate ratio 4.1, 95% CI, 1.1–15.8, P =.03) compared with female athletes without history of SRC. Conclusions: Female adolescent athletes with history of SRC showed a greater risk of LE MSK injury compared with athletes with no history of SRC. Future work is still needed to understand the underlying mechanisms associated with future LE MSK injury following SRC and interventions that ameliorate elevated injury risk. [ABSTRACT FROM AUTHOR]

Context: Dual-task (simultaneous cognitive–motor activities) assessments have been adapted into reliable and valid clinical concussion measures. However, abundant motor and cognitive variations leave researchers and clinicians uncertain about which combinations elicit the intended dual-task effect. Our objective was to examine differences between commonly employed dual-task motor and cognitive combinations among healthy, college-aged individuals. Design: Cross-sectional laboratory study. Methods: Twenty participants (age: 21.3 [2.4] y; height: 176.0 [9.1] cm; mass: 76.0 [16.4] kg; 20% with concussion history) completed 4 motor tasks (gait, tandem gait, single-leg balance, and tandem balance) under 5 cognitive conditions (single task, subtraction, month reversal, spelling backward, and visual Stroop) in a research laboratory. The motor performance outcomes were spatiotemporal variables for gait and tandem gait and center of pressure path length (in centimeters) for single-leg and tandem balance. Cognitive outcomes were response rate (responses/second) and cognitive accuracy. We used separate repeated-measures analyses of variance for each motor and cognitive outcome with post hoc Tukey t tests. Results: Gait velocity, gait stride length, and tandem gait velocity demonstrated significant cognitive–motor interactions (P's <.001) such that all dual-task conditions resulted in varyingly slower or shorter movement than single task. Conversely, single-leg balance (P =.627) and tandem balance (P =.434) center of pressure path length did not significantly differ among the dual-task cognitive conditions or relative to single task. Statistically significant cognitive–motor interactions were observed only for spelling backward accuracy (P =.004) and response rates for spelling backward, month reversal, and visual Stroop (P's <.001) such that worse accuracy, but faster response rates, occurred during motor tasks. Conclusions: Gait and tandem gait motor tasks accompanied with spelling backward or subtraction cognitive tasks demonstrated consistently strong dual-task effects and, therefore, may be the best suited for clinical and research use following concussion. [ABSTRACT FROM AUTHOR]

Context: Mindfulness interventions (yoga, meditation) in traumatic brain injury populations show promising improvements in injury outcomes. However, most studies include all injury severities and use in-person, general programming lacking accessibility and specificity to the nuance of concussion. Therefore, this study investigated the feasibility and preliminary effectiveness of an online, concussion-focused meditation intervention among young adults with a concussion history. Design: Unblinded, single-arm, pilot intervention. Methods: Fifteen young adults aged 18 to 30 with a concussion history within the past 5 years completed 10 to 20 minutes per day of online, guided meditations for 6 weeks. Feasibility was assessed using the Feasibility of Intervention Measure. Concussion symptoms were measured using the Rivermead Post-Concussion Symptom Questionnaire, perceived stress the Perceived Stress Scale-10, and mindfulness the Five Facet Mindfulness Questionnaire. Descriptive statistics described the study sample and determined intervention adherence and feasibility. Paired sample t tests were used to examine preintervention/postintervention changes in concussion symptoms, perceived stress, and mindfulness, with descriptive statistics further detailing significant t tests. Results: Fifteen participants were enrolled, and 12 completed the intervention. The majority completed 5+ days per week of the meditations, and Feasibility of Intervention Measure (17.4 [1.8]) scores indicated high feasibility. Concussion symptom severity significantly decreased after completing the meditation intervention (11.3 [10.3]) compared with before the intervention (24.5 [17.2]; t[11] = 3.0, P =.01). The number of concussion symptoms reported as worse than before their concussion significantly decreased after completing the meditation intervention (2.7 [3.9]) compared with before the intervention (8.0 [5.7]; t[11] = 3.7, P =.004). Postintervention, 83.33% (n = 10) reported lower concussion symptom severity, and 75.00% (n = 9) reported less concussion symptoms as a mild, moderate, or severe problem (ie, worse than before injury). Conclusions: Findings suggest positive adherence and feasibility of the meditation intervention, with the majority reporting concussion symptom improvement postintervention. Future research is necessary to expand these pilot findings into a large trial investigating concussion-specific meditation programming. [ABSTRACT FROM AUTHOR]

The complex pathology of mild traumatic brain injury (mTBI) is a main contributor to the difficulties in achieving a successful therapeutic regimen. Thyroxine (T4) administration has been shown to prevent the cognitive impairments induced by mTBI in mice but the mechanism is poorly understood. To understand the underlying mechanism, we carried out a single cell transcriptomic study to investigate the spatiotemporal effects of T4 on individual cell types in the hippocampus and frontal cortex at three post-injury stages in a mouse model of mTBI. We found that T4 treatment altered the proportions and transcriptomes of numerous cell types across tissues and timepoints, particularly oligodendrocytes, astrocytes, and microglia, which are crucial for injury repair. T4 also reversed the expression of mTBI-affected genes such as Ttr, mt-Rnr2, Ggn12, Malat1, Gnaq, and Myo3a, as well as numerous pathways such as cell/energy/iron metabolism, immune response, nervous system, and cytoskeleton-related pathways. Cell-type specific network modeling revealed that T4 mitigated select mTBI-perturbed dynamic shifts in subnetworks related to cell cycle, stress response, and RNA processing in oligodendrocytes. Cross cell-type ligand-receptor networks revealed the roles of App, Hmgb1, Fn1, and Tnf in mTBI, with the latter two ligands having been previously identified as TBI network hubs. mTBI and/or T4 signature genes were enriched for human genome-wide association study (GWAS) candidate genes for cognitive, psychiatric and neurodegenerative disorders related to mTBI. Our systems-level single cell analysis elucidated the temporal and spatial dynamic reprogramming of cell-type specific genes, pathways, and networks, as well as cell-cell communications as the mechanisms through which T4 mitigates cognitive dysfunction induced by mTBI.

Context: This study investigated individual sociocognitive factors from the theory of planned behavior and their relationship to exercise for postconcussion recovery. Design and Methods: Four hundred and fifty-nine Australian adults, two-thirds of whom had no concussion history (66%), completed an online survey of their beliefs and attitudes toward exercise for postconcussion recovery. Secondary questions evaluated program design features that could affect engagement (eg, session frequency). Results: Structured equation modeling found that subjective norms were the strongest significant predictor of intention to participate in exercise for postconcussion recovery. Perceived behavioral control was also a significant predictor of intention to participate but to a lesser extent. Attitude did not predict participation intention. The design features identified as key were personalization and being supervised during the program. Conclusions: This study found that people's intention to participate in a program of exercise postconcussion recovery is shaped by individual psychological factors and identified program design features that could be adjusted for increased engagement. Program success could be maximized through strategies such as supporting individuals to have a stronger sense of control over their participation through the choice of session timing or frequency and harnessing the influence of significant others via supportive messaging from key professionals. [ABSTRACT FROM AUTHOR]

Context: Early physical activity (PA) after concussion may promote symptom resolution. Prior studies have investigated exercise frequency/duration, yet precise PA intensity or volume required for optimal recovery requires further investigation. moderate to vigorous physical activity (MVPA) is beneficial for physical health. We investigated whether sedentary time, light activity time, MVPA time, or activity frequency in the weeks following concussion are associated with time to symptom resolution among adolescents. Design: Prospective cohort study. Methods: Adolescents 10–18 years of age were tested ≤14 days of concussion and followed until symptom resolution. At the initial visit, participants rated symptom severity and were provided wrist-worn activity trackers to monitor PA for the following week. PA behavior was categorized each day based on heart rate: sedentary (resting), light PA (50%–69% age-predicted max heart rate), and MVPA (70%–100% age-predicted max heart rate). Symptom resolution was defined as the date when participants reported cessation of concussion-like symptoms. Patients were not given specific PA instructions, though some may have received instructions from their physician. Results: Fifty-four participants were included in the study (54% female; mean age = 15.0 [1.8] y; initially assessed 7.5 [3.2] d after concussion). Female athletes recorded more sedentary time (900 [46] vs 738 [185] min/d; P =.01; Cohen d = 0.72), and less time in light PA (194.7 [64.5] vs 224 [55] min/d; P =.08; Cohen d = 0.48) and MVPA (23 [17] vs 38 [31] min/d; P =.04; Cohen d = 0.58) than male athletes. After adjusting for sedentary time, hours per day with >250 steps, sex, and initial symptom severity, more MVPA time was associated with faster symptom resolution time (hazard ratio = 1.016; 95% confidence interval, 1.001–1.032; P =.04). Conclusion: Our findings offer preliminary insight into how varying PA intensities affect concussion recovery, as MVPA may be a higher intensity than what is typically prescribed in concussion care. [ABSTRACT FROM AUTHOR]

Dizziness following mild traumatic brain injury (mTBI), or concussion, is common and can encompass multiple sensations reflecting diverse aetiologies. This exploratory study investigated the types of dizzy sensations experienced, their evolution, and relationship with other post-concussion symptoms. Thirty New Zealanders (24 female) aged 49 ± 16 years who experienced dizziness or imbalance following their injury completed the Dizziness Handicap Inventory, Visual Vertigo Analogue Scale, and the Hospital Anxiety and Depression Scale. Additional custom questionnaires probed subjective experiences of dizziness and balance, headaches, and difficulties with auditory processing and vision. Just over half the participants (56.7%) experienced a single mTBI. The median time interval since the injury was 16 months (IQR = 24 months). Participants usually reported multiple dizzy symptoms which developed within a week of the injury, although delays of up to six months were reported. Most participants (70%) felt their symptoms improved over time, while lack of improvement was associated with a history of multiple mTBI (P = 0.020). Moderate to strong correlations between questionnaire scores representing dizziness handicap, visual vertigo severity, and auditory processing difficulties (P < 0.001) suggest that dizziness and sensory impairment following mTBI are multi-modal and likely to benefit from holistic, multidisciplinary treatment. [ABSTRACT FROM AUTHOR]

Non-neurological factors such as the “expectation as etiology” or the “good old days” bias (EE/GOD bias) may partially explain persistent symptoms following mild traumatic brain injury (MTBI). What is less clear from existing research is the degree to which EE/GOD bias is related to other psychological correlates of persistent post-concussive symptoms (PPCS). We examined whether the EE/GOD bias was related to illness perception beliefs, intolerance of uncertainty, suggestibility, and domain identification. Participants with MTBI history and without (controls) reported frequency and severity of current PPCS; the MTBI group additionally reported premorbid PPCS. Participants also completed measures of psychological factors potentially associated with PPCS. Consistent with previous studies of the EE/GOD bias, the MTBI group endorsed less premorbid PPCS than current PPCS and when compared to the current symptom report of the control group. The MTBI group also endorsed more current PPCS than the control group. Higher EE/GOD bias was associated with several aspects of illness identity, including belief that symptoms would be more chronic, greater illness-related psychological distress, and greater cogniphobia. Higher EE/GOD bias was also related to higher intolerance of uncertainty and stronger personal identification with memory abilities. Regression showed that perceived symptom timeline, cogniphobia, and domain identification were unique predictors of EE/GOD bias. Findings confirm that the EE/GOD bias is seen in individuals with self-reported history of MTBI and corresponds to other psychological processes that potentially explain ongoing MTBI symptoms, providing greater insight into the potential mechanisms of PPCS. Future studies should examine the EE/GOD bias and associated psychological correlates in a clinical population and also assess for potential neuropsychological correlates. Findings suggest that psychological factors and premorbid symptom report should be considered in clinical assessment and also suggest potential mechanisms of treatment of individuals with acute MTBI or prolonged MTBI symptoms. [ABSTRACT FROM AUTHOR]

AbstractObjectiveDesignStudy SampleResultsConclusionsThe current study aimed to explore (1) school-aged children’s auditory and cognitive abilities and (2) their perceptions (self-reported and parents) of listening behaviours and symptoms following mild traumatic brain injury (mTBI).Prospective cohort study.Twenty-one children aged 8 to 12 participated in this study. Eleven children with mTBI were diagnosed in the emergency department, and 10 were matched controls. They were assessed twice, in the acute (≤14 days) and chronic (≥3 months) stages post-injury, using six central auditory behavioural tests, a cognitive screening battery, and questionnaires. ANOVA and correlation analysis were performed.Group differences were present in three auditory tests as children with mTBI obtained poorer scores than controls (Pitch Pattern Sequence Tests - PPST: p = 0.037; Gap In Noise test - GIN threshold: p = 0.046; Duration Pattern Test - DPT: p = 0.053), but not for perceived listening behaviours and cognitive abilities. Correlations were found only between perceived listening behaviours and reported mTBI symptoms for parents (p =0.014) and children (p =0.002).Auditory abilities, mostly those related to temporal processing, were affected following mTBI, independently of cognitive abilities. Better identification of auditory processing difficulties following mTBI will improve treatment and resource allocation for children. [ABSTRACT FROM AUTHOR]

Background: Concussion and communication researchers have yet to study how post‐concussion communication changes affect youths' daily lives. The lack of attention paid to how young people respond to communication changes during concussion recovery constitutes a significant gap in current concussion management research and practices. Aims: To explore how youth respond to the effects of post‐concussion communication changes in their daily life, including (1) daily routines, (2) relationships with family members, (3) relationships with peers and (4) participation in school/work and community activities. Methods & Procedures: Five youths (16–25 years) and three family members participated in this arts‐based reflexive collective case study. Ecocultural theory provided the theoretical framework for study design, data collection and analysis. Cases consist of (1) pre‐interview demographic information, (2) three 60–90‐min virtual interviews, (3) optional family member interviews, (4) multi‐media arts‐based participant‐generated materials representing participants' experiences of communication change and concussion, and (5) researcher observations, discussions and reflexive journal entries. Reflexive thematic analysis was used to analyse the data. Outcomes & Results: Analysis yielded four themes that illustrate the ways youth navigated and adapted to post‐concussion communication changes: (1) navigating changes in communication tasks, daily roles, and identity; (2) re‐negotiating relationships and emotional reactions; (3) seeking control and learning to let go during recovery; and (4) helping youth adapt to post‐concussion communication changes. Conclusions & Implications: The study findings deepen our understanding of the impact of post‐concussion communication changes on youths' daily lives and underscore considerations critical to the development of communication‐focused concussion education programs and interventions tailored specifically for youth. What this paper adds: What is already known on the subject: Youth is a critical period of social and emotional development. Communication is integral to identity, relationships, participation in daily activities and well‐being. Concussions can affect speech clarity, fluency, understanding and use of language, and social interactions. Re‐engaging in routine activities and pre‐injury roles can be challenging for youth experiencing communication changes as part of complex concussion recoveries. What this paper adds to the existing knowledge: Findings from this research illuminate how youth navigate and adapt to communication changes post‐concussion and support the development of youth‐focused communication education programs, assessments and interventions. Youth participants actively managed their recoveries by developing innovative strategies to support their communication during daily activities, learning about communication, practicing communication tasks sequentially, and facing fears. Youth also reframed and challenged narrow views of 'normal communication'. What are the potential or actual clinical implications of this work?: Findings highlight the need for more youth‐ and communication‐focused education materials and programs within youth concussion management protocols. Information about the specific ecological and sociocultural factors youth encounter during concussion recovery is needed to develop targeted communication‐focused education and intervention programs for youth and their families to mitigate risks of isolation, loneliness, and mental health concerns and increase youths' participation in family, community and cultural life. By learning from youth about how communication changes affected their participation in daily activities, identity and relationships, clinicians can provide information and interventions to reduce adverse listener reactions and help young people feel supported and understood. [ABSTRACT FROM AUTHOR]

Objective: Determine how a) masculinity, b) optimism bias, and c) perceived pressure from stakeholders predict concussion reporting intentions and behavior. Participants: Collegiate student-athletes (n = 369). Methods: Student-athletes completed surveys of Conformity to Masculine Norms Inventory-46 (nine sections), optimism bias (optimist, neutral, pessimist), perceived pressure from stakeholders (six stakeholder sections), reporting intentions (symptom and concussion), and behavior (symptom and concussion). Four separate stepwise multivariate regression analyses were conducted. Results: A one-point increase in playboy, heterosexual self-preservation, being neutral or optimist compared to a pessimist symptom reporting intention decreased. A one-point increase in sport primacy, perceived pressure from athletic administration, being neutral or optimist compared to pessimist concussion reporting intentions increased 0.05, and decreased 0.23, 0.35, and 0.32, respectively. A one-point increase in violence and playboy increased the odds of being a "non-reporter" by 30% and 40%. Conclusions: Pessimistic views regarding concussion risks may result in greater concussion reporting intentions, however these findings did not influence behavior. [ABSTRACT FROM AUTHOR]

Mild traumatic brain injury (mTBI) is a common occurrence around the world, associated with a variety of blunt force and torsion injuries affecting all age groups. Most never reach medical attention, and the identification of acute injury and later clearance to return to usual activities is relegated to clinical evaluation—particularly in sports injuries. Advanced structural imaging is rarely performed due to the usual absence of associated acute anatomic/hemorrhagic changes. This review targets physiologic imaging techniques available to identify subtle blood–brain barrier dysfunction and white matter tract shear injury and their association with chronic traumatic encephalopathy. These techniques provide needed objective measures to assure recovery from injury in those patients with persistent cognitive/emotional symptoms and in the face of repetitive mTBI. [ABSTRACT FROM AUTHOR]

BACKGROUND: A significant factor for the high prevalence of traumatic brain injury (TBI) among U.S. service members is their exposure to explosive munitions leading to blast-related TBI. Our understanding of the specific clinical effects of mild TBI having a component of blast mechanism remains limited compared to pure blunt mechanisms. OBJECTIVE: The purpose of this review is to provide a synopsis of clinical research findings on the long-term effects of blast-related mild TBI derived to date from the Long-Term Impact of Military-Relevant Brain Injury Consortium - Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC). METHODS: Publications on blast-related mild TBI from LIMBIC-CENC and the LIMBIC-CENC prospective longitudinal study (PLS) cohort were reviewed and their findings summarized. Findings from the broader literature on blast-related mild TBI that evaluate similar outcomes are additionally reviewed for a perspective on the state of the literature. RESULTS: The most consistent and compelling evidence for long-term effects of blast-related TBI is for poorer psychological health, greater healthcare utilization and disability levels, neuroimaging impacts on brain structure and function, and greater headache impact on daily life. To date, evidence for chronic cognitive performance deficits from blast-related mild TBI is limited, but futher research including crucial longitudinal data is needed. CONCLUSION: Commentary is provided on: how LIMBIC-CENC findings assimilate with the broader literature; ongoing research gaps alongside future research needs and priorities; how the scientific community can utilize the LIMBIC-CENC database for independent or collaborative research; and how the evidence from the clinical research should be assimilated into clinical practice. [ABSTRACT FROM AUTHOR]

Primary Objective: This is Part II of a four-part opinion review on traditional neuropsychological assessment methods and findings associated with mild traumatic brain injury (mTBI). This Part II review focuses on historical, psychometric and statistical issues involving traditional neuropsychological methods that have been used in neuropsychological outcome studies of mTBI, but demonstrates the critical limitations of traditional methods. Research Design: This is an opinion review. Methods and Procedures: Traditional neuropsychological tests are dated and lack specificity in evaluating such a heterogenous and complex injury as occurs with mTBI. Main Outcome and Results: In this review, we demonstrate traditional neuropsychological methods were never developed as standalone measures for detecting subtle changes in neurocognitive or neurobehavioral functioning and likewise, never designed to address the multifaceted issues related to underlying mTBI neuropathology symptom burden from having sustained a concussive brain injury. Conclusions: For neuropsychological assessment to continue to contribute to clinical practice and outcome literature involving mTBI, major innovative changes are needed that will likely require technological advances of novel assessment techniques more specifically directed to evaluating the mTBI patient. These will be discussed in Part IV. [ABSTRACT FROM AUTHOR]

Background: The purpose of the study was to identify whether the presence of a pre-injury psychiatric history, subacute post-concussive symptoms (PCS) and personality traits were predictive of less favorable social reintegration for 3 months following a mild traumatic brain injury (mTBI). Method: A total of 76 patients with mTBI were included, and the presence of a pre-injury psychiatric history was identified from the medical chart. One-month post-accident, these patients completed the Millon Multiaxial Clinical Inventory, 3rd Edition assessing personality traits and the Rivermead Post-Concussion Symptoms Questionnaire to measure subacute PCS. Social reintegration was measured using the Mayo-Portland Adaptability Inventory, 4th Edition at 3-month post-accident. Results: The presence of pre-injury psychiatric history, high levels of subacute PCS and Cluster B personality traits such as histrionic and borderline features were significant predictors of social reintegration quality at 3-month post injury. Conclusion: This study provides new insights on cluster B personality traits and its influence on recovery and social reintegration at 3-month post mTBI. [ABSTRACT FROM AUTHOR]

Background: Worldwide, mild traumatic brain injury, synonymous with concussion, affects more than 30–50 million each year. The incidence of concussion in Denmark is estimated to be about 20,000 yearly. Although complete resolution normally occurs within a few weeks, up to a third develop persistent post-concussion symptoms (PPCS) beyond 3 months. Evidence for effective treatment strategies is scarce. The objective of this study is to evaluate the efficacy of the novel intervention GAIN Lite added to enhanced usual care (EUC) for adults with mild-to-moderate PPCS compared to EUC only. Methods: An open-label, parallel-group, two-arm randomised controlled superiority trial (RCT) with 1:1 allocation ratio. Potential participants will be identified through the hospital's Business Intelligence portal of the Central Denmark Region or referred by general practitioners within 2–4 months post-concussion. Participants with mild-to-moderate PPCS will be randomly assigned to either (1) EUC or (2) GAIN Lite added to EUC. GAIN Lite is characterised as a complex intervention and has been developed, feasibility-tested and process evaluated before effect evaluation in the RCT. GAIN Lite contains an initial remote interview, self-administrated e-learning videos and voluntary remote counselling with an allocated occupational- or physiotherapist. Sixty-six participants will be recruited to each group. Primary outcomes are mean changes in PPCS and limitations in daily life from baseline to 24 weeks after baseline. Discussion: GAIN Lite is a low-intensity intervention for adults with mild-to-moderate PPCS. Offering a remote intervention may improve access to rehabilitation and prevent chronification for individuals with mild-to-moderate PPCS. Moreover, GAIN Lite will facilitate access to healthcare, especially for those with transportation barriers. Overall, GAIN Lite may provide an accessible, flexible and convenient way to receive treatment based on sound theories and previous evidence of effective interventions for adults with mild-to-moderate PPCS. Trial registration: ClinicalTrials.gov NCT05233475. Registered on February 10, 2022. [ABSTRACT FROM AUTHOR]

Introduction: Mild traumatic brain injury (mTBI) represents a major public health concern and affects millions of people worldwide every year. Diagnosis mainly relies on clinical criteria and computed tomography (CT) scans. GFAP (glial fibrillary acidic protein) and UCH-L1 (ubiquitin carboxyl-terminal hydrolase-L1) have been recently studied as potential biomarkers of mTBI. This study retrospectively evaluated the possible use of these combined biomarkers as negative predictors for excluding brain injuries in patients with suspected mTBI in the emergency department. Methods: Adult patients (n = 130) enrolled at Tor Vergata University Hospital (Rome, Italy), consecutively registered at the triage of the emergency department between October 2022 and January 2023, with non-penetrating TBI and Glasgow Coma Scale (GCS) score of 13–15, were considered. All eligible patients underwent intracranial CT scans and blood tests, within 12 h after trauma, for GFAP and UCH-L1 serum concentrations. Results: Intracranial CT detected injuries in only seven patients (5%); GFAP and UCH-L1 tested positive in 96 patients and negative in 34 patients (74% vs. 26%). Combined biomarkers had a sensitivity equal to 1.00 (95% CI 0.64-1.00) and a negative predictive value (NPV) of 1.00 (0.99-1.00) in mTBI diagnosis with a negative CT. Conclusions: Combined laboratory tests for GFAP and UCH-L1 biomarkers might play a potential clinical role in avoiding unnecessary head CT scans after mTBI in emergency departments. [ABSTRACT FROM AUTHOR]

ObjectiveMethodResultsConclusionIn this study, we evaluated the psychometric properties of the Depression Anxiety Stress Scales 21 items (DASS-21) in a mild traumatic brain injury (mTBI) sample.Treatment-seeking adults (n = 347) were recruited from outpatient rehabilitation services in New Zealand. Dimensionality, reliability, person separation index, and differential item functioning (DIF) of the DASS-21 were examined using Rasch analysis.Initial analysis of the complete 21-item DASS showed poor overall fit due to problems with individual items. Fit to the Rasch model was excellent when treated as three composite scores. The stress subscale demonstrated adequate model fit, dimensionality and good reliability. For anxiety, fit was not good, reliability was unsatisfactory and DIF was evident on one item. When this item was removed, fit to the model was still inadequate as was reliability. DIF was also evident for depression, but when this item was removed, fit to the model was adequate.The DASS-21 is a psychometrically sound measure of distress and stress for adults seeking treatment following mTBI. Ordinal to interval score conversion tables are provided to increase the precision of measurement. When assessing depression in a mTBI population, a 6-item depression subscale is recommended. Caution is advised in using the DASS-21 anxiety subscale alone. [ABSTRACT FROM AUTHOR]

This review was designed to (1) determine the extent to which the clinical science on sport-related concussion treatment and rehabilitation has considered social determinants of health (SDoH) or health equity and (2) offer recommendations to enhance the incorporation of SDoH and health equity in concussion treatment research and clinical care. The Concussion in Sport Group consensus statement (2023) was informed by two systematic reviews examining prescribed rest or exercise following concussion and targeted interventions to facilitate concussion recovery. We examined 31 studies, including 2,698 participants, from those two reviews. Race (k = 6; 19.4%) and ethnicity (k = 4; 12.9%) of the study samples were usually not reported. Four studies examined ethnicity (i.e., Hispanic), exclusively as a demographic category. Five studies (16.1%) examined race as a demographic category. Three studies (9.7%) examined socioeconomic status (SES; measured as household income) as a demographic category/sample descriptor and one study (3.2%) examined SES in-depth, by testing whether the treatment and control groups differed by SES. Five studies examined an SDoH domain in a descriptive manner and four studies in an inferential/intentional manner. No study mentioned SDoH, health equity, or disparities by name. Many studies (61.3%) excluded participants based on demographic, sociocultural, or health factors, primarily due to language proficiency. The new consensus statement includes recommendations for concussion treatment and rehabilitation that rely on an evidence base that has not included SDoH or studies addressing health equity. Researchers are encouraged to design treatment and rehabilitation studies that focus specifically on underrepresented groups to determine if they have specific and unique treatment and rehabilitation needs, whether certain practical modifications to treatment protocols might be necessary, and whether completion rates and treatment adherence and response are similar. [ABSTRACT FROM AUTHOR]

Mild Traumatic Brain Injury (mTBI) is a prevalent neurological condition that can lead to persistent cognitive impairments, disrupting memory, attention, and executive function. In this study, we explore the mechanisms of cognitive decline in mTBI through the lens of Markov blankets--a theoretical framework that delineates the statistical boundary between the brain's internal and external states. By simulating the impact of mTBI on sensory, active, internal, and external states, we demonstrate how disruptions to the Markov blanket structure contribute to impairments in predictive coding and cognitive processing. Our simulation introduces noise and connectivity reductions that mimic the neurometabolic and synaptic changes following mTBI, revealing delayed sensory processing, impaired motor function, and cognitive instability. These findings highlight the importance of Markov blankets in maintaining cognitive integrity and offer novel insights into the pathophysiology of post-concussion syndrome. Understanding how mTBI disrupts the brain's functional architecture through Markov blanket disturbances may inform more effective diagnostic and therapeutic approaches. [ABSTRACT FROM AUTHOR]

Assessment of sport-related concussion (SRC) has begun to include patient-reported outcome measures. However, understanding of which health limitations are most meaningful to adolescents after SRC is limited. To explore patient-perceived activity limitations after SRC and throughout recovery to return to play and mapped according to the International Classification of Functioning, Disability, and Health (ICF) model. Longitudinal study. Secondary school athletic training facilities. Fifty patients (41 males, 5 females, 4 sex not reported, age = 14.9 ± 3.5 years, grade = 10.2 ± 0.93 level) with a medically diagnosed SRC. The Patient Specific-Functional Scale (PSFS) was used to assess changes in the patient's condition and the effect the injury posed on their ability to perform activities. The PSFS is a self-reported assessment of health used to identify activity limitations and rate the difficulty of performing those tasks. The PSFS was administered to patients on days 3 (D3) and 10 (D10) after SRC and at return to play. Activities affected by injury were coded into common categories and themes by a 3-person research team for subsequent analysis. The coded themes were also mapped to the ICF domains, chapters, and categories. The dependent variables were the PSFS themes, number of activities endorsed, PSFS scores, ICF domains, chapters, and categories. Descriptive analyses and frequencies were reported for the dependent variables. A total of 157 different activities were identified at D3 and coded into 28 categories that fit into 6 themes: activities of daily living, cognitive and school (COG), sports and physical activity (SPA), screen time, sleep, and social. On D3, all patients (50/50) identified at least 1 activity limitation. Most related to SPA (37.6%) and COG (31.2%). Sixty percent of patients endorsed activity limitations at D10, primarily in COG (38.6%) and SPA (36.6%). All (100%) response categories were mapped to the ICF, with most (75%) fitting the activities and participation domain. Our primary findings suggest that SRC influences many facets of the lives of adolescent athletes. Specifically, adolescent athletes identified activity restrictions primarily related to physical activity and sports participation. [ABSTRACT FROM AUTHOR]

Objective: To identify (1) university educators' perceptions of academic adjustments (AA), and (2) if teaching experience correlated with AA perceptions following concussion. Participants: Two hundred twenty educators. Methods: University educators were invited to complete a survey containing four subsections; this manuscript focuses on AA following concussion. Objective 1 was descriptive; we conducted spearman's rho correlations between years of teaching experience and AA perceptions to address objective 2. Results: Educators were moderately familiar with AA but were not confident in their knowledge about AA following concussion. Participants who provided AA following concussion most often allowed excused absences and extra time for exams/assignments. There were no significant relationships between teaching experience and perceptions of AA. Conclusions: University educators largely feel unprepared to provide or recommend AA following concussion but had favorable AA perceptions following concussion. Standardized policies or referral sites within the university system may be warranted to improve post-concussion AA. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI) and cognitive profiles in patients with mild traumatic brain injury (mTBI) are often discordant. Conventional MRI seldom captures the full extent of pathological changes in the normal‐appearing white matter (NAWM). The divided subtracted inversion recovery (dSIR) technique may enhance T1 differences in NAWM, making them easily visible. We aimed to implement dSIR on a clinical scanner and tested results in mTBI patients. To produce dSIR images, Inversion Recovery‐Turbo Spin Echo sequences were modified using six different inversion times (TI) on a 3‐T scanner in healthy participants and patients with mTBI. The multiple TIs determined normal white (TIshort) and gray matter (TIlong) nulling points in healthy subjects, which were used to create dSIR images. In one patient, the protocol was repeated at 3 months to identify changes after rehabilitation. Diffusion tensor imaging (DTI)‐derived mean diffusivity (MD) and fractional anisotropy (FA) maps were aligned to dSIR images to ensure that signal was not artefactual. Ten healthy participants (five females; age 24 ± 3 [95% CI: 21, 26] years) were included. TIshort and TIlong were set at 450 and 750 ms, respectively. In both patients (one male, age 17 years; one female, age 14 years), dSIR images revealed areas with increased T1 in the NAWM not visible on conventional MRI. dSIR‐based hyperintensities corresponded to elevated MD and reduced FA. Substantial changes were found at follow‐up with improvement in DTI‐based parameters. dSIR images enhance subtle changes in the NAWM of patients with mTBI by amplifying their intrinsic T1 signal. [ABSTRACT FROM AUTHOR]

Athletes in contact and collision sports can sustain frequent subconcussive head impacts. Although most impacts exhibit low kinematics around or below 10 g of head linear acceleration, there is growing concern regarding the cumulative effects of repetitive sports head impacts. Even mild impacts can lead to brain deformations as shown through neuroimaging and finite element modeling, and thus may result in mild and transient effects on the brain, prompting further investigations of the biomechanical dose—brain response relationship. Here we report findings from a novel laboratory study with continuous monitoring of brain activity through electroencephalography (EEG) during controlled soccer head impacts. Eight healthy participants performed simulated soccer headers at 2 mild levels (6 g, 4 rad/s and 10 g, 8 rad/s) and three directions (frontal, oblique left, oblique right). Participants were instrumented with an inertial measurement unit (IMU) bite bar and EEG electrodes for synchronized head kinematics and brain activity measurements throughout the experiment. After an impact, EEG exhibited statistically significant elevation of relative and absolute delta power that recovered within two seconds from the impact moment. These changes were statistically significantly higher for 10 g impacts compared with 6 g impacts in some topographical regions, and oblique impacts resulted in contralateral delta power increases. Post-session resting state measurements did not indicate any cumulative effects. Our findings suggest that even mild soccer head impacts could lead to immediate, transient neurophysiological changes. This study paves the way for further dose-response studies to investigate the cumulative effects of mild sports head impacts, with implications for long-term athlete brain health. [ABSTRACT FROM AUTHOR]

Sporting helmets contain force attenuating materials which reduce traumatic head injury risk and may influence sport-related concussion (SRC) sequelae. The purpose of this study was to examine the association of sport helmet status with SRC-clinical presentation and recovery trajectories in men's collegiate athletes. Sport helmet status was based on the nature of sports being either helmeted/non-helmeted. 1070 SRCs in helmeted (HELM) sports (Men's-Football, Ice Hockey, and Lacrosse), and 399 SRCs in non-helmeted (NOHELM) sports (Men's-Basketball, Cheerleading, Cross Country/Track & Field, Diving, Gymnastics, Soccer, Swimming, Tennis, and Volleyball) were analyzed. Multivariable negative binomial regression models analyzed associations between sport helmet status and post-injury cognition, balance, and symptom severity, adjusting for covariate effects (SRC history, loss of consciousness, anterograde/retrograde amnesia, event type). Kaplan-Meier curves evaluated median days to: initiation of return to play (iRTP) protocol, and unrestricted RTP (URTP) by sport helmet status. Log-rank tests were used to evaluate differential iRTP/URTP between groups. Two independent multivariable Weibull accelerated failure time models were used to examine differential iRTP and URTP between groups, after adjusting for aforementioned covariates and symptom severity score. Overall, the median days to iRTP and URTP was 6.3 and 12.0, respectively, and was comparable across NOHELM- and HELM-SRCs. Post-injury symptom severity was lower (Score Ratio 0.90, 95%CI 0.82, 0.98), and cognitive test performance was higher (Score Ratio 1.03, 95%CI 1.02, 1.05) in NOHELM-compared to HELM-SRCs. Estimated time spent recovering to iRTP/URTP was comparable between sport helmet status groups. Findings suggest that the grouping of sports into helmeted and non-helmeted show slight differences in clinical presentation but not recovery. [ABSTRACT FROM AUTHOR]

Concussion has been described in the United States (US) collegiate student–athlete population, but female-specific findings are often underrepresented and underreported. Our study aimed to describe female collegiate student–athletes' initial injury characteristics and return to activity outcomes following concussion. Female collegiate student–athletes (n = 1393) from 30-US institutions experienced a concussion and completed standardized, multimodal concussion assessments from pre-injury through unrestricted return to play (uRTP) in this prospective, longitudinal cohort study. Initial injury presentation characteristics, assessment, and return to activity outcomes [<48-h (acute), return to learn, initiate return to play (iRTP), uRTP] were collected. We used descriptive statistics to report injury characteristics, return to activity outcomes, and post-injury assessment performance change categorization (worsened, unchanged, improved) based on change score confidence rank criteria across sport contact classifications [contact (n = 661), limited (n = 446), non-contact (n = 286)]. The median (25th to 75th percentile) days to return to learn was 6.0 (3.0–10.0), iRTP was 8.1 (4.8–13.8), and uRTP was 14.8 (9.9–24.0), but varied by contact classification. Across contact levels, the majority experienced worse SCAT total symptom severity (72.8–82.6%), ImPACT reaction time (91.2–92.6%), and BSI-18 total score (45.2–51.8%) acutely relative to baseline, but unchanged BESS total errors (58.0–60.9%), SAC total score (71.5–76.1%), and remaining ImPACT domains (50.6–66.5%). Our findings provide robust estimates of the typical female collegiate student–athlete presentation and recovery trajectory following concussion, with overall similar findings to the limited female collegiate student–athlete literature. Overall varying confidence rank classification was observed acutely. Our findings provide clinically-relevant insights for athletes, clinicians, researchers, and policymakers to inform efforts specific to females experiencing concussion. [ABSTRACT FROM AUTHOR]

Background/Objectives: "Return-to-play" and "return-to-learn" after a concussion are familiar concepts due to guidelines proposed by the Concussion in Sport Group and Heads-Up Initiative. The purpose of this commentary is to expand upon the current consensus guidelines for treatment of concussed children and adolescents, as well as provide guidelines for returning to physical education (RT-PE) classes. Proposal: The authors propose one general and four subtype-specific guidelines post-concussion injury. This framework highlights the role of physical therapists in the management of children with prolonged recovery. The final RT-PE determination should occur with documented medical clearance from a licensed healthcare provider trained in the evaluation and management of a concussion. Conclusions: Despite significant gains regarding the management of concussed children and adolescents, confusion remains regarding RT-PE post-concussion. To eliminate ambiguity and promote adherence to a gradual return to activity protocols, the authors developed guidelines based on current evidence and recommendations. [ABSTRACT FROM AUTHOR]

ObjectivesMethodsResultsConclusionEvaluate professional rugby players’ self-reported perceived understanding of the head injury assessment (HIA) and return to play (RTP) processes and determine factors related to understanding and trust pertaining to these processes.An electronic survey measured concepts of interest. A thematic analysis of player understanding was performed, and player statements were coded.207 U.S. Major League Rugby (MLR) players participated (26.7 ± 3.4 years). HIA and RTP protocol understanding was not correlated with concussion history (p = 0.41). International rugby experience and trust regarding MLR support of the following protocols and opposing team medical staff practices varied in their relationship to HIA understanding. Trust that all MLR teams follow the same protocols was positively correlated with all HIA questions (ps < 0.03). No HIA questions were correlated with trust in their own team’s medical staff. All trust questions were significantly correlated with RTP process understanding. Qualitative analysis identified four HIA- and RTP-related themes: education needs, staffing needs, HIA criticisms, and importance of player safety.International playing experience and greater trust in the MLR and league stakeholders were associated with greater player understanding of the HIA and RTP protocols. These results provide insight into the importance of educating players on league-specific concussion protocols. [ABSTRACT FROM AUTHOR]

Objective: The purpose was to examine clinical profiles in concussed children aged 5–9 and 10–12 years and compare them with those of adolescents >12 years. Methods: This study included patients aged 5–18 years presenting to a specialty care concussion program with a sports- and recreation-related (SRR) concussion ≤28 days postinjury. Demographics, injury mechanisms, symptoms, and clinical features were assessed. Chi-squared tests, one-way ANOVA, and Kruskal-Wallis were used for comparisons across age groups. Results: A total of 3280 patients with SRR concussion were included: 5.0% were 5–9 years, 18.4% were 10–12 years, and 76.6% were 13–18 years. Younger age groups had more males than females (5–9 years: 70.7% vs. 29.3%) and more commonly sustained their injury during limited- (28.7%), and non-contact (7.9%) activities compared to other age groups (p < 0.01). Younger children presented less symptoms frequently (p ≤ 0.042), but higher symptom severity in somatic and emotional domains (p ≤ 0.016). Fewer 5–9-year-olds reported changes in school (25.6%), sleep (46.3%), and daily habits (40.9%) than adolescents (p < 0.001). Conclusions: Among SRR-concussed children and adolescents, we found significant age-related variations in demographics, injury mechanism, symptoms, and clinical features. Recognizing these unique features in younger children may facilitate targeted management and treatment. [ABSTRACT FROM AUTHOR]

Background: Mild traumatic brain injury (mTBI), i.e. a TBI with an admission Glasgow Coma Scale (GCS) of 13–15, is a common cause of emergency department visits. Only a small fraction of these patients will develop a traumatic intracranial hemorrhage (tICH) with an even smaller subgroup suffering from severe outcomes. Limitations in existing management guidelines lead to overuse of computed tomography (CT) for emergency department (ED) diagnosis of tICH which may result in patient harm and higher healthcare costs. Objective: To perform a systematic review and meta-analysis to characterize known and potential novel risk factors that impact the risk of tICH in patients with mTBI to provide a foundation for improving existing ED guidelines. Methods: The literature was searched using MEDLINE, EMBASE and Web of Science databases. Reference lists of major literature was cross-checked. The outcome variable was tICH on CT. Odds ratios (OR) were pooled for independent risk factors. Results: After completion of screening, 17 papers were selected for inclusion, with a pooled patient population of 26,040 where 2,054 cases of tICH were verified through CT (7.9%). Signs of a skull base fracture (OR 11.71, 95% CI 5.51–24.86), GCS < 15 (OR 4.69, 95% CI 2.76–7.98), loss of consciousness (OR 2.57, 95% CI 1.83–3.61), post-traumatic amnesia (OR 2.13, 95% CI 1.27–3.57), post-traumatic vomiting (OR 2.04, 95% CI 1.11–3.76), antiplatelet therapy (OR 1.54, 95% CI 1.10–2.15) and male sex (OR 1.28, 95% CI 1.11–1.49) were determined in the data synthesis to be statistically significant predictors of tICH. Conclusion: Our meta-analysis provides additional context to predictors associated with high and low risk for tICH in mTBI. In contrast to signs of a skull base fracture and reduction in GCS, some elements used in ED guidelines such as anticoagulant use, headache and intoxication were not predictive of tICH. Even though there were multiple sources of heterogeneity across studies, these findings suggest that there is potential for improvement over existing guidelines as well as a the need for better prospective trials with consideration for common data elements in this area. PROSPERO registration number CRD42023392495. [ABSTRACT FROM AUTHOR]

BackgroundObjective(s)MethodsResultsConclusionsIndividuals with persistent symptoms following a mild traumatic brain injury (mTBI) demonstrate improved satisfaction with their performance of self-identified rehabilitation goals after completing a combined occupational therapy and physiotherapy group intervention. However, the relationship between factors associated with developing persistent symptoms following an mTBI and satisfaction with their performance of self-identified goals after completing an intervention are unknown.To evaluate whether factors associated with developing persistent symptoms influence satisfaction with the performance of self-identified goals after completing a combined occupational therapy and physiotherapy group intervention.During intake assessments, individuals with persistent mTBI symptoms completed the satisfaction section of the Canadian Occupational Performance Measure (COPM-S), the Rivermead Post-Concussion Symptom Questionnaire (RPQ), and the Generalized Anxiety Disorder Seven-Item Scale (GAD-7). Participants re-rated their satisfaction with performance of self-identified goals using the COPM-S during their discharge assessment. The influence of age, sex, days since injury, education, mechanism of injury, baseline COPM-S, GAD-7, and RPQ scores on goal satisfaction ratings were analyzed using a binomial logistic regression.One hundred and ninety-eight individuals (44.7 ± 13.6 years old) were included in this study, and 92% experienced a clinically important improvement in their goal satisfaction ratings after completing the intervention. Neither age, sex, days since injury, education, mechanism of injury, baseline COPM-S, GAD-7, or RPQ scores significantly influenced satisfaction with performance of self-identified goals.Factors associated with developing persistent symptoms following an mTBI did not influence goal satisfaction after completing a combined physiotherapy and occupational therapy group intervention. [ABSTRACT FROM AUTHOR]

Purpose: This study explores the association of the American Society of Anesthesiologists (ASA) score with 90-day mortality in complicated mild traumatic brain injury (mTBI) patients, and in trauma patients without a TBI. Methods: This retrospective study was conducted using a cohort of trauma patients treated at a level III trauma center in Stockholm, Sweden from January to December 2019. The primary endpoint was 90-day mortality. The population was identified using the Swedish Trauma registry. The Trauma and Injury Severity Score (TRISS) was used to estimate the likelihood of survival. Trauma patients without TBI (NTBI) were used for comparison. Data analysis was conducted using R software, and statistical analysis included univariate and multivariate logistic regression. Results: A total of 244 TBI patients and 579 NTBI patients were included, with a 90-day mortality of 8.2% (n = 20) and 5.4% (n = 21), respectively. Deceased patients in both cohorts were generally older, with greater comorbidities and higher injury severity. Complicated mTBI constituted 97.5% of the TBI group. Age and an ASA score of 3 or higher were independently associated with increased mortality risk in the TBI group, with odds ratios of 1.04 (95% 1.00–1.09) and 3.44 (95% CI 1.10–13.41), respectively. Among NTBI patients, only age remained a significant mortality predictor. TRISS demonstrated limited predictive utility across both cohorts, yet a significant discrepancy was observed between the outcome groups within the NTBI cohort. Conclusion: This retrospective cohort study highlights a significant association between ASA score and 90-day mortality in elderly patients with complicated mTBI, something that could not be observed in comparative NTBI cohort. These findings suggest the benefit of incorporating ASA score into prognostic models to enhance the accuracy of outcome prediction models in these populations, though further research is warranted. [ABSTRACT FROM AUTHOR]

Introduction: Education is strongly advocated as a key component of treatment for mild traumatic brain injury (mTBI) in clinical guidelines. However, there is mixed evidence on the benefit of education. This study aimed to evaluate a new education resource for mTBI. CLARITY is a freely available animated video based on a biopsychosocial conceptualization of mTBI, explaining the complex psychological, environmental and biological mechanisms behind symptoms and recovery.1 Methods: 24 adults with a history of mTBI participated in this mixed method study to examine prior experience of mTBI education and to evaluate CLARITY. Following viewing of the education video participants’ were invited to engage in a semi-structured interview and to share their perceptions of it via an online anonymous questionnaire. Results: Thematic analysis of semi-structured interviews revealed one overarching theme: education is the foundation of recovery. Participants emphasised the critical role of coherent education in facilitating understanding, engagement in rehabilitation, and positive expectations during recovery. However, the first subtheme was that existing foundations are weak. Participants’ previous education was often limited in scope, inconsistent, and delivered in inaccessible ways. The second subtheme was that new foundations are stronger. Participants responded positively to CLARITY, highlighting its explanatory biopsychosocial approach, focus on mental health factors and accessible delivery methods as key strengths. Questionnaire responses revealed favourable endorsement of CLARITY’s utility, comprehensibility and accessibility. Discussion: Recommendations for minor refinements to CLARITY were provided and made, as well as for its use in health care services. [ABSTRACT FROM AUTHOR]

Background: Arachnoid cysts (AC) are associated with a risk of rupture or haemorrhage following head impact and pose a potential predisposing factor for significant complications of sport-related concussion. Despite a recognised association between ACs and intracranial haemorrhage/cyst rupture, the risk profile of participating in contact sports with AC is not well defined. We report a retrospective case series of players presenting to the Birmingham Sports Concussion Clinic between 2017 and 2023 and underwent MRI head, with a comprehensive review of the prior literature. Results: 432 athletes underwent MRI of which 11 were identified to have AC (middle fossa n = 8; posterior fossa n = 2, intraventricular n = 1). Average maximal diameter was 4.1 ± 1.2 cm. 64% had a protracted recovery (≥ 3 months). 9% experienced an AC specific complication (cyst rupture, complete neurological recovery, maximal diameter 6.5 cm, Galassi II, 4 previous concussions). 91% of patients (mean maximal diameter 3.9 ± 1.0 cm) experienced no complications despite multiple previous accumulated sports-related concussions (mean 3.3, range 1–9). Case studies from the literature are summarised (n = 63), with 98% reporting complications, none of which resulted in adverse or unfavourable neurological outcomes. Across prospective and retrospective cohort studies, 1.5% had a structural injury, and (where outcome was reported) all had a favourable outcome. Conclusions: AC is an incidental finding in athletes, with the majority in our cohort having sustained serial concussions without AC complication. The single complication within this cohort occurred in the largest AC, and AC size is proposed as a tentative factor associated with increased risk of contact sports participation. Complications of AC appear to be a rare occurrence. This case series and review has not identified evidence to suggest that participation in sports with AC is of significant risk, though individualised assessment and discussion of the potential risks of contact sports participation should be offered. Key Points: Incidental arachnoid cysts were found to occur in 2.5% of athletes presenting after sports-related concussion. Of 11 athletes with AC and a history of concussion, one (9%) had experienced a prior complication of AC (cyst rupture) and made a full recovery. A comprehensive review of the prior literature suggests an overall risk of complications of 1.5%, with all reported outcomes from cases describing a full neurological recovery. Overall, complications of AC in athletes after sport-related concussion appear to be rare, with no recorded cases of significant neurological consequences. [ABSTRACT FROM AUTHOR]

A potential source of novel biomarkers for mTBI is the kynurenine pathway (KP), a metabolic pathway of tryptophan (Trp), that is up‐regulated by neuroinflammation and stress. Considering that metabolites of the KP (kynurenines) are implicated in various neuropsychiatric diseases, exploration of this pathway could potentially bridge the gap between physiological and psychological factors in the recovery process after mTBI. This study, therefore, set out to characterize the KP after mTBI and to examine associations with long‐term outcome. Patients were prospectively recruited at the emergency department (ED), and blood samples were obtained in the acute phase (<24 h; N = 256) and at 1‐month follow‐up (N = 146). A comparison group of healthy controls (HC; N = 32) was studied at both timepoints. Trp, kynurenines, and interleukin (IL)‐6 and IL‐10 were quantified in plasma. Clinical outcome was measured at six months post‐injury. Trp, xanthurenic acid (XA), and picolinic acid (PA) were significantly reduced in patients with mTBI relative to HC, corrected for age and sex. For Trp (d = −0.57 vs. d = −0.29) and XA (d = −0.98 vs. d = −0.32), larger effects sizes were observed during the acute phase compared to one‐month follow‐up, while for PA (d = −0.49 vs. d = −0.52) effect sizes remained consistent. Findings for other kynurenines (e.g., kynurenine, kynurenic acid, and quinolinic acid) were non‐significant after correction for multiple testing. Within the mTBI group, lower acute Trp levels were significantly related to incomplete functional recovery and higher depression scores at 6 months post‐injury. No significant relationships were found for Trp, XA, and PA with IL‐6 or IL‐10 concentrations. In conclusion, our findings indicate that perturbations of the plasma KP in the hyperacute phase of mTBI and 1 month later are limited to the precursor Trp, and glutamate system modulating kynurenines XA and PA. Correlations between acute reductions of Trp and unfavorable outcomes may suggest a potential substrate for pharmacological intervention. [ABSTRACT FROM AUTHOR]

Concussions are increasingly recognized as a public health concern. This paper evaluates Canadian concussion care guidelines, advocating for the inclusion of a broader range of healthcare professionals (HCPs) in concussion assessment, diagnosis, and management. It emphasizes the role of chiropractors, in addition to medical doctors (MDs) and nurse practitioners (NPs), highlighting their extensive training in musculoskeletal and neurological disorders. Chiropractors are adept at managing symptoms like headache, neck pain, and dizziness, and employing evidence-based, comprehensive interventions including patient education, exercise therapy, manual therapy, cervicovestibular rehabilitation, and return-to-sport (RTS) protocols. The paper also addresses regional variations in chiropractors' roles, focusing on Ontario's "Rowan's Law," and argues that limiting aspects of concussion care (assessment, diagnosis, RTS clearance) to MDs and NPs may result in healthcare inefficiencies and inequities. The findings are significant for policymakers and healthcare leaders, indicating a need for updated concussion care guidelines that integrate and utilize diverse HCPs. This could lead to improved patient outcomes, healthcare efficiency, and equity in concussion management across Canada. [ABSTRACT FROM AUTHOR]

Background: Persistent symptoms have been reported in up to 50% of the 27 million people with mild traumatic brain injuries (mTBI) every year. MRI findings are currently limited by low diagnostic and prognostic sensitivities, constraining the value of imaging in the stratification of patients following mTBI. Limbic system structures are promising brain regions in offering prognostic factors for symptom persistence following mTBI. The objective of this study was to associate volume and symmetry of limbic system structures with the presence and persistence of common symptoms in patients with mTBI. Methods: This study focused on 524 adults (aged 18–82), 58% female, with 82% injured in motor vehicle accidents and 28% reporting loss of consciousness (LOC). Magnetic resonance imaging (MRI) data included a sagittal 3D T1-weighted sequence with 1.2 mm slice thickness, with voxel sizes of 0.93 mm × 0.93 mm × 1.2 mm, obtained a median of 156 days after injury. Symptom diagnosis and persistence were collected retrospectively from patient medical records. Intracranial volume-adjusted regional volumes per side utilizing automated volumetric analysis (NeuroQuant®) were used to calculate total volume, laterality index, and side-independent asymmetry. Covariates included age, sex, LOC, and days from injury. Limbic volumetrics did not relate to symptom presentation, except the (-) association between headache presence and thalamus volume (adjusted odds ratio = 0.51, 95% confidence interval = 0.32, 0.85). Headache, balance problems, anxiety, and depression persistence was (-) associated with thalamus volume (hazard ratio (HR) 1.25 to 1.94). Longer persistence of balance problems was associated with (-) lateral orbitofrontal cortex volume (HR = 1.33) and (+) asymmetry of the hippocampus (HR = 0.27). Persistence of cognitive deficits was associated with (+) asymmetry in the caudal anterior cingulate (HR = 0.67). Depression persistence was associated with (+) asymmetry in the isthmus of the cingulate gyrus (HR = 5.39). Persistence of anxiety was associated with (-) volume of the parahippocampal gyrus (HR = 1.67), orbitofrontal cortex (HR > 1.97), and right-biased laterality of the entorhinal cortex (HR = 0.52). Conclusions: Relative volume and asymmetry of the limbic system structures in patients with mTBI are associated with the persistence of symptoms, particularly anxiety. The conclusions of this study are limited by the absence of a reference group with no mTBI. [ABSTRACT FROM AUTHOR]

Objectives: To quantify norms and changes in eye-tracking proficiency, and determine vestibular symptom correlations in varsity college athletes following acute mild traumatic brain injury (mTBI). We hypothesized that mTBI impacts central coordination between the vestibular and oculomotor systems with resultant changes in eye-tracking proficiency that are correlated with vestibular symptom provocation. Design: Retrospective cohort study. Setting: Sports medicine care at a single institution. Patients: One hundred and nineteen college athletes diagnosed with mTBI by a physician between 2013 and 2019. Interventions: N/A. Main Outcome Measures: Standard deviation of tangential error, standard deviation of radian error, mean phase error, and horizontal gain from virtual reality-based, circular eye-tracking goggles used at baseline and within 72 hours post-mTBI. Headache, dizziness, nausea, and fogginess provocation after the Vestibular Ocular Motor Screening (VOMS) smooth pursuits subtest compared with pretest baseline, assessed within 72 hours post-mTBI. Results: One hundred and nineteen college athletes (N 5 56 women and 63 men) aged 18 to 24 years sustained a total of 177 mTBI. Forty-four percent of athletes displayed abnormal eye-tracking on at least 1 eye-tracking measure following acute mTBI compared with their baseline. From the VOMS, horizontal gain showed medium-sized to large-sized positive correlations with headache (r50.34) and dizziness (r50.54), respectively. Mean phase error showed a medium-sized negative correlation with nausea (r 5 20.32) on the VOMS. Conclusions: Eye-tracking proficiency was impaired and correlated with vestibular symptom provocation following acute mTBI in college athletes. Future research should examine eye-tracking proficiency testing in other acute care settings to support mTBI diagnosis. [ABSTRACT FROM AUTHOR]

To evaluate some confounding factors that influence the concentrations of S100 calcium binding protein B (S100B), glial fibrillary acidic protein (GFAP), and ubiquitin carboxyl-terminal hydrolase L-1 (UCH-L1) in older individuals. Indeed, recent guidelines have proposed the combined use of S100B and the "GFAP-UCH-L1" mTBI test to rule out mild traumatic brain injuries (mTBI). As older adults are the most at risk of mTBI, it is particularly important to understand the confounding factors of those mTBI rule-out biomarkers in aging population. The protein S100B and the "GFAP and UCH-L1" mTBI test were measured using Liaison XL (Diasorin) and Alinity I (Abbott), respectively, in 330 and 341 individuals with non-suspected mTBI from the SarcoPhAge cohort. S100B, GFAP and UCH-L1 were all significantly correlated with renal function whereas alcohol consumption, Geriatric Depression Score (GDS), smoking habits and anticoagulant intake were not associated with any of these three biomarkers. Body mass index (BMI) and age were associated with GFAP and UCH-L1 expression while sex and mini-mental state examination (MMSE) were only associated with GFAP. According to the manufacturer's cut-offs for mTBI rule-out, only 5.5 % of participants were positive for S100B whereas 66.9 % were positive for the "GFAP-UCH-L1" mTBI test. All positive "GFAP-UCH-L1" mTBI tests were GFAP+/UCH-L1-. Among individuals with cystatin C>1.55 mg/L, 25 % were positive for S100B while 90 % were positive for the mTBI test. Our data show that confounding factors have different impacts on the positivity rate of the "GFAP-UCH-L1" mTBI test compared to S100B. [ABSTRACT FROM AUTHOR]

This narrative review scrutinizes research exploring sex-based differences in experiences of sport-related concussion. The article argues that the limitations of epidemiological studies identifying the greater incidence and severity of concussion among females require that these findings are read with caution. It secondly argues that the dominant explanations for these data are based on and extend historical tendencies to "other" female participation in sport and construct male experiences as the "norm". Finally, the article critiques policy recommendations related to these research findings, arguing that they are likely to embed rather than challenge sex inequality in sport, and that they are both impractical and unethical. While this commentary builds on a broader body of work advocating greater sex/gender equality in sports science research, the prominence of social concerns about concussions in sport makes the broader implications of the focus on sex and sport-related concussion particularly problematic and thus in need of redress. [ABSTRACT FROM AUTHOR]

Individuals with mild traumatic brain injury (mTBI) often complain of executive functioning (EF) difficulties. There is a discrepancy between self-reported EF impairment and EF deficits on neuropsychological tests, with some arguing that self-report EF is more related to real-world functioning than EF tests. However, research suggests that self-reported EF may be related more to emotional distress and is vulnerable to invalid reporting. We examined the vulnerability of the short form Barkley Deficits in Executive Functioning Scale (BDEFS) to invalid reporting, using a simulated mTBI paradigm. We included four groups: individuals simulating mTBI with (N = 24) and without (N = 21) histories of mTBI/other psychological conditions and controls with (N = 21) and without (N = 25) histories of mTBI/other psychological conditions. As hypothesized, simulators performed worse on the BDEFS Total Score and EF Symptom Count relative to controls; however, this effect was larger within those who had no self-reported history of mTBI/other psychological conditions. We identified a preliminary cutoff on the EF Symptom Count that detected 42.8% of simulators, with 95% specificity relative to the controls with histories of mTBI/other psychological conditions. The present study emphasizes the need for validity scales on self-report EF measures such as the BDEFS. [ABSTRACT FROM AUTHOR]

Considering that diagnostic decisions about mTBI are often predicated on clinical symptom criteria, it is imperative to determine which initial presentation features of mTBI have prognostic significance for identifying those at high risk for long-term functional impairment. Zoom interview Participants: Male, former NCAA Division I, and professional-level National Football League (NFL) athletes (n = 177) between the ages of 27 and 85 (M = 54.1, SD = 14.7). Cross-sectional case-control. Main Measures: History of mild TBI, history of loss of consciousness (LOC), depression symptoms, insomnia, neurobehavioral symptoms. Number of mTBI exposures did not predict neurobehavioral symptoms (B = 0.21, SE = 0.18, p = 0.23), but number of mTBI + LOC events did (B = 2.27, SE = 0.64, p = <.001). Further analysis revealed that the number of mTBI + LOC events predicted neurobehavioral symptoms indirectly through both depression (B = 0.85, 95% CI = [0.27, 1.52) and insomnia (B = 0.81, 95% CI = [0.3, 1.4]). Further, the direct effect of mTBI + LOC events on neurobehavioral symptoms became non-significant when depression and insomnia were added to the model (B = 0.78, SE = 0.45, p = 0.08). Findings support LOC at time of injury as an important predictor of long-term outcomes. Additionally, results suggest depression and insomnia as potential mediators in the association between mTBI + LOC and neurobehavioral symptoms. These findings provide justification for early depression and insomnia symptom monitoring following mTBI + LOC. [ABSTRACT FROM AUTHOR]

To examine challenges in return to work (RTW) for persons with persistent postconcussion symptoms (PPCS) experienced by the affected employees and their managers. A survey of employees (S-E) and two surveys of managers (S-M1, S-M2) executed 4 months apart to capture the time perspective. Inclusion: Adults aged 18–66 with PPCS > 4 weeks, employed at the time of mTBI who returned to work within the previous year. Managers involved in their RTW process. Work status, working hours, work functioning (Work Role Functioning Questionnaire, WRFQ), work productivity. Ninety-two employees and 66 managers were recruited. Three-fourths of the employees had returned to work but only one-third worked under similar conditions. Weekly working hours decreased from 36,3 hours (SD = 10,5) before mTBI to 17,6 hours (SD = 9,7). Employees had difficulties with tasks 43% of time (WRFQ). They needed more breaks, struggled with multitasking and work speed. About 65.9% experienced affected work productivity. Managers reported lack of knowledge and difficulties assessing the number of working hours and suitable tasks. Most employees returned to work but only a minority worked under similar conditions as before mTBI. Employees and managers struggled to estimate workload. The affected employees and their workplaces need a long-term RTW support. [ABSTRACT FROM AUTHOR]

Persistent symptoms post-mild traumatic brain injury (mTBI) includes autonomic dysregulation (AD). The composite autonomic symptoms score, (COMPASS-31), was developed to quantify AD symptom severity in the last year, which limits clinical utility. The primary aim was to determine validity of a modified-COMPASS-31 measuring symptoms in the last month compared to the original, secondarily to compare both original and modified versions to the Neurobehavioral Symptom Inventory (NSI), and tertiarily to detect change post-treatment of the modified-COMPASS-31 compared to NSI and headache intensity (HI). Thirty-three military personnel with persistent headache post-mTBI. Total and domain scores for COMPASS-31 (original vs. modified) NSI and HI at baseline. Change in modified-COMPASS-31. NSI, and HI. Baseline COMPASS-31 versions were comparable and highly correlated (r = 0.72, p < 0.001), they were moderately correlated at best to the NSI (r < 0.6), which may suggest differences in measurement metrics. The mean change in modified-COMPASS-31 scores (15.4/100, effect size 0.8) was mild to moderately correlated to the change in HI (r = 0.39) score, but not to NSI (r = 0.28). The modified-COMPASS-31 appears to be valid, can measure change of AD symptom severity, and is recommended as an outcome measure. [ABSTRACT FROM AUTHOR]

Objective: After a concussion, 1 in 3 patients report persistent symptoms and experience long-term consequences interfering with daily functioning, known as persistent concussion symptoms (PCS). Evidence suggests PCS is (partly) maintained by anxious thoughts about brain functioning, recovery, and experienced symptoms, leading to avoidance behaviors, which may prevent patients from meeting life demands. We aimed to investigate the efficacy of a newly developed intensive exposure intervention for individuals with PCS after concussion aimed to tackle avoidance behavior. Setting: Participants took part in the intervention at the Maastricht University faculty. Participants: Four participants who experienced PCS after concussion partook in the exploratory study. Participants’ age ranged between 20 and 32 (mean = 26.5, SD = 5.9) years, with an average length of time after the concussion of 9.8 months. Design: A concurrent multiple-baseline single-case design was conducted. The baseline period (A phase) length was randomly determined across participants (3, 4, 5, or 6 weeks). The exposure intervention (B phase) was conducted by psychologists over a 4-week period and consisted of 3 stages: exploration (2 sessions), active exposure (12 sessions conducted over 1 week), and 2 booster sessions. Main Measures: Participants answered daily questions on a visual analog scale related to symptom experience, satisfaction with daily functioning, and degree of avoidance of feared activities. Additional outcomes included symptom severity, catastrophizing, fear of mental activity, anxiety, depression, and societal participation. Results: Tau-U yielded significant effects (P < .05) for all participants on all measures when comparing baseline and intervention phases. The pooled standardized mean difference was high for all measures (symptom experience = 0.93, satisfaction of daily functioning = 1.86, and activity avoidance = −2.05). Conclusions: The results show efficacy of the newly developed intensive exposure treatment for PCS after concussion, which is based on the fear avoidance model. Replication in a larger heterogeneous sample is warranted and needed. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to identify the cerebral physiologic response to aerobic exercise in individuals with a symptomatic concussion, highlighting available knowledge and knowledge gaps in the literature. Design: A systematic scoping review was conducted and reported in keeping with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. A search of EMBASE, MEDLINE, SCOPUS, BIOSIS, and Cochrane libraries was conducted on June 15, 2023 (from database inception). An online systematic/scoping review management system was used to remove duplicates, and the remaining articles were screened for inclusion by 2 researchers. Inclusion criteria required articles to be original research published in peer- reviewed journals. Additionally, studies were required to have an aerobic exercise component, include a measure of cerebral physiology during a bout of aerobic exercise, exclude moderate and/or severe traumatic brain injury (TBI) populations, and be in the English language. Both human and animal studies were included, with participants of any age who were diagnosed with a mild TBI/concussion only (ie, Glasgow Coma Scale score ≥ 13). Studies could be of any design as long as a measure of cerebral physiologic response to a bout of aerobic exercise was included. Results: The search resulted in 1773 articles to be screened and data from 3 eligible studies were extracted. Conclusions: There are currently too few studies investigating the cerebral physiologic response to aerobic exercise following concussion or mild TBI to draw definitive conclusions. Further research on this topic is necessary since understanding the cerebral physiologic response to aerobic exercise in the concussion and mild TBI populations could assist in optimizing exercise-based treatment prescription and identifying other targeted therapies. [ABSTRACT FROM AUTHOR]

Objectives: People may experience a myriad of symptoms after mild traumatic brain injury (mTBI), but the relationship between symptoms and objective assessments is poorly characterized. This study sought to investigate the association between symptoms, resting heart rate (HR), and exercise tolerance in individuals following mTBI, with a secondary aim to examine the relationship between symptom-based clinical profiles and recovery. Methods: Prospective observational study of adults aged 18 to 65 years who had sustained mTBI within the previous 7 days. Symptoms were assessed using the Post-Concussion Symptom Scale, HR was measured at rest, and exercise tolerance was assessed using the Buffalo Concussion Bike Test. Symptom burden and symptom-based clinical profiles were examined with respect to exercise tolerance and resting HR. Results: Data from 32 participants were assessed (mean age 36.5 ± 12.6 years, 41% female, 5.7 ± 1.1 days since injury). Symptom burden (number of symptoms and symptom severity) was significantly associated with exercise intolerance (P = .002 and P = .025, respectively). Physiological and vestibular-ocular clinical profile composite groups were associated with exercise tolerance (P = .001 and P = .014, respectively), with individuals who were exercise intolerant having a higher mean number of symptoms in each profile than those who were exercise tolerant. Mood-related and autonomic clinical profiles were associated with a higher resting HR (>80 bpm) (P = .048 and P = .028, respectively), suggesting altered autonomic response for participants with symptoms relating to this profile. After adjusting for age and mechanism of injury (sports- or non–sports-related), having a higher mood-related clinical profile was associated with persisting symptoms at 3 months postinjury (adjusted odds ratio = 2.08; 95% CI, 1.11-3.90; P = .013). Conclusion: Symptom-based clinical profiles, in conjunction with objective measures such as resting HR and exercise tolerance, are important components of clinical care for those having sustained mTBI. These results provide preliminary support for the concept that specific symptoms are indicative of autonomic dysfunction following mTBI. [ABSTRACT FROM AUTHOR]

Objective: To investigate which factors within an at-risk group make patients less likely to benefit from preventive treatment following mild traumatic brain injury (mTBI). Setting: Inclusion in 3 level I trauma centers in the Netherlands. Data collection through surveys as outpatients. Participants: mTBI patients (18-66 years), reporting 3 or more complaints 2 weeks postinjury (at-risk status). Eighty-four patients included and randomized (39 patients cognitive behavioral therapy, 45 patients telephonic counseling). Eighty patients filled out the questionnaires 12 months postinjury. Post hoc analysis investigating 80 patients as 1 at-risk group receiving psychological treatment. Design: Post hoc study of a randomized controlled trial (RCT). Binomial logistic regression performed determining which variables 2 weeks postinjury contributed strongly to unsuccessful return to work/study (RTW) and unfavorable outcome at 12 months. Main measures: RTW and functional outcome as measured with the Glasgow Outcome Scale-Extended (GOSE) at 12 months postinjury. Results: Out of 80 patients, 43 (53.8%) showed a favorable functional outcome at 12 months, and 56 (70%) patients had a full RTW. Patients with unfavorable outcome had a higher age and higher reports of anxiety, depression at 2 weeks and 12 months postinjury. Patients with an unsuccessful RTW had a higher age and higher reports of depression, and posttraumatic stress disorder at 2 weeks and 12 months postinjury. A logistic regression model for functional outcome (GOSE) was statistically significant (χ²7 = 40.30, P < .0001). Of 6 predictor variables, 3 were significant: anxiety, depression, and treatment condition. For RTW, logistic regression was also statistically significant (χ²7 = 19.15, P = .008), with only 1 out of 6 predictor variables (ie, age) being significant. Conclusion: Main findings comprise differences in demographic and psychological measures between patients with favorable and unfavorable outcomes and patients with RTW versus no RTW. Prediction models of outcome and RTW showed several psychological measures at 2 weeks greatly determining patients’ likelihood benefitting from the preventive treatment. Results suggest that from the beginning there are some patients for whom a short preventive treatment is not sufficient. Selection and treatment of at-risk patients might be better based on psychological symptoms instead of posttraumatic complaints. [ABSTRACT FROM AUTHOR]

To investigate dizziness, vestibular/oculomotor symptoms, and cervical spine proprioception among adults with/without a concussion history. Adults ages 18–40 years with/without a concussion history completed: dizziness handicap inventory (DHI), visio-vestibular exam (VVE), and head repositioning accuracy (HRA, assesses cervical spine proprioception). Linear regression models were used to assess relationships between (1) concussion/no concussion history group and VVE, HRA, and DHI, and (2) DHI with HRA and VVE for the concussion history group. We enrolled 42 participants with concussion history (age = 26.5 ± 4.5 years, 79% female, mean = 1.4 ± 0.8 years post-concussion) and 46 without (age = 27.0 ± 3.8 years, 74% female). Concussion history was associated with worse HRA (β = 1.23, 95% confidence interval [CI]: 0.77, 1.68; p < 0.001), more positive VVE subtests (β = 3.01, 95%CI: 2.32, 3.70; p < 0.001), and higher DHI scores (β = 9.79, 95%CI: 6.27, 13.32; p < 0.001) after covariate adjustment. For the concussion history group, number of positive VVE subtests was significantly associated with DHI score (β = 3.78, 95%CI: 2.30, 5.26; p < 0.001) after covariate adjustment, while HRA error was not (β = 1.10, 95%CI: −2.32, 4.51; p = 0.52). Vestibular/oculomotor symptom provocation and cervical spine proprioception impairments may persist chronically (i.e., 3 years) after concussion. Assessing dizziness, vestibular/oculomotor and cervical spine function after concussion may inform patient-specific treatments to address ongoing dysfunction. • Cervical spine evaluations after concussion may help identify sources of dysfunction. • Vestibular/oculomotor symptom provocation was more severe in those with concussion history. • Dizziness and functional impairments may persist chronically after concussion. [ABSTRACT FROM AUTHOR]

ntroduction. Best-practice guidelines recommend that patients are followed-up to check if they have recovered following a mild traumatic brain injury (mTBI) and to refer to concussion services, if needed. However, in New Zealand, rates of follow-up are low and access to concussion services can be delayed. Aim. We aimed to improve rates of follow-up and access to concussion services for mTBI patients aged ≥8 years by the implementation of a supported health pathway and test its success. Methods. The pathway included a decision support tool, funded follow-up appointments, clinician training and a patient education resource. Sociodemographics, injury details and proportions of patients receiving a follow-up by type and time were extracted from the Accident Compensation Corporation (ACC) database between 18 May 22 and 30 June 23 and compared to national ACC data prior to implementation. Results. Data were extracted for 220 patients, with a mean age of 31.5 years, 51.4% female and 21.4% Māori and Pacific. There was an increase in the proportion of patients receiving a follow-up from 36% pre-implementation to 56.8% post-implementation. Sixty-three patients (28.6%) accessed a concussion service postimplementation compared to 10% pre-implementation. Time to concussion service reduced from an average of 55 (s.d. = 65.4) to 37 days (29.5). Discussion. Risk factor criteria within the decision support tool need to be weighted to improve specificity of referrals. Timing from injury to medical review in primary care needs to be considered. This quality improvement project provides preliminary evidence for implementation of a supported health care pathway for mTBI. [ABSTRACT FROM AUTHOR]