Mild Traumatic Brain Injury Characteristics and Symptoms in Preschool Children: How Do They Differ to School Age Children? A Multicenter Prospective Observational Study.

OBJECTIVE: To investigate if preschool children differ to school age children with mild traumatic brain injury (TBI) with respect to injury causes, clinical presentation, and medical management. DESIGN: A secondary analysis of a dataset from a large, prospective and multisite cohort study on TBI in children aged 0-18 years, the Australian Paediatric Head Injury Rules Study. SETTING: Nine pediatric emergency departments (ED) and 1 combined adult and pediatric ED located across Australia and New Zealand. PARTICIPANTS: 7080 preschool aged children (2-5 years) were compared with 5251 school-age children (6-12 years) with mild TBI (N= (N=12,331) MAIN OUTCOME MEASURES: Clinical report form on medical symptoms, injury causes, and management. RESULTS: Preschool children were less likely to be injured with a projectile than school age children (P<.001). Preschool children presented with less: loss of consciousness (P<.001), vomiting (P<.001), drowsiness (P=.002), and headache (P<.001), and more irritability and agitation (P=.003), than school-age children in the acute period after mild TBI. Preschool children were less likely to have neuroimaging of any kind (P<.001) or to be admitted for observation than school age children (P<.001). CONCLUSIONS: Our large prospective study has demonstrated that preschool children with mild TBI experience a different acute symptom profile to older children. There are significant clinical implications with symptoms post-TBI used in medical management to aid decisions on neuroimaging and post-acute intervention.

Convergence insufficiency in patients with post-concussion syndrome is accompanied by a higher symptom load: a cross-sectional study.

OBJECTIVE: To estimate the prevalence of convergence insufficiency (CI) in adult patients with post-concussion syndrome and determine the impact of CI on symptom load. METHODS: Cross-sectional study of 103 patients with neurological symptoms 2-6 months after a concussion. Symptoms were assessed with the Rivermead Post Concussion Symptoms Questionnaire (RPQ), and CI was diagnosed using near point of convergence, vergence facility, and the Convergence Insufficiency Symptom Survey. The RPQ score for patients with and without CI was compared, and sensitivity, specificity, and area under the receiver operating characteristic curve for the two visually related RPQ questions as indicators of CI were calculated. RESULTS: The proportion of patients diagnosed with symptomatic CI was 20.4% (95% confidence interval: 13.1-29.5%). The RPQ score was significantly higher for patients with symptomatic CI both before (p = .01) and after removal of the two visually related questions in the RPQ-questionnaire (p = .03). The two visually related RPQ questions were unable to detect CI. CONCLUSION: In patients with post-concussion syndrome, the load of nonvisual symptoms is higher in the presence of CI. A prospective interventional study on CI is required to study the relationship between CI and other post-concussion symptoms.

Individualized spectral filters alleviate persistent photophobia, headaches and migraines in active duty military and Veterans following brain trauma.

PURPOSE: Consistent with association between photophobia and headache, growing evidence suggests an underlying causal relationship between light sensitivity and central pain. We investigated whether an intervention to regulate light sensitivity by filtering only wavelengths causing difficulties for the specific individual could alleviate headaches/migraines resulting from traumatic brain injury (TBI). METHODS: Secondary data analysis of a clinical database including N = 392 military personnel (97% men, 3% women), ranging in age from 20 to 51 years, diagnosed with TBI, persistent headaches/migraines, and light sensitivity. The average elapsed time from TBI diagnosis to intervention was 3 years. Headache/migraine severity, frequency, medication use, and difficulties related to daily functioning were assessed pre and 4-12 weeks post-intervention with individualized spectral filters. RESULTS: Monthly migraine frequency decreased significantly from an average of 14.8 to 1.9, with 74% reporting no migraines post-intervention. Prescription and over-the-counter medication use decreased by more than 70%. Individuals also reported significant improvement in light sensitivity, headaches/migraine severity, and physical and perceptual symptoms. CONCLUSIONS: Wearing individualized spectral filters was associated with symptom relief, increased subjective quality of reported health and well-being, and decreased objective medication use for TBI-related persistent headaches/migraines. These results support a suggested relationship between dysregulated light sensitivity and central regulation of pain.

Treatment of chronic symptoms following mild traumatic brain injury with transcranial LED: a sham run-in pilot study of photobiomodulation therapy.

PRIMARY OBJECTIVE: We evaluated whether photobiomodulation with red/near infrared light applied transcranially via light emitting diodes (LED) was associated with reduced symptoms and improved cognitive functioning in patients with chronic symptoms following mild traumatic brain injury. RESEARCH DESIGN: Participants (3 men, 6 women; 22-61 years-old) underwent a 6-week intervention involving 18 40-minute transcranial LED treatment sessions. METHODS AND PROCEDURES: Reliable change indices were calculated for 10 neuropsychological test scores and 3 self-report questionnaires of subjective cognition, post-concussion symptoms, and depression at baseline and following treatment. Questionnaires were also administered after 2-week sham and at 1-month and 2-month follow-ups. MAIN OUTCOME AND RESULTS: Only 2 participants improved on neuropsychological testing. On questionnaires, 4 reported improved cognition, 5 reported improved post-concussion symptoms, and 3 reported improved depression. Significant improvement in 2 or more domains was reported by 4 participants and mostly maintained at both follow-ups. CONCLUSIONS: Most participants did not improve on neuropsychological testing. A minority self-reported improvement in symptoms, potentially explained by the intervention, psychiatric medication changes, placebo effects, or other factors. Selecting participants with different clinical characteristics, and dosing and delivery system changes, may produce different results. A study design accounting for placebo effects appears warranted in future trials.

Fatigue recovery and connected factors following paediatric concussion.

OBJECTIVE: Using a biopsychosocial framework and the three-factor fatigue model, we aimed to (1) plot recovery of fatigue over the 3 months following paediatric concussion and (2) explore factors associated with persisting fatigue during the first 3 months postconcussion. METHODS: 240 children and adolescents aged 5-18 years (M=11.64, SD=3.16) completed assessments from time of injury to 3 months postinjury. Separate linear mixed effects models were conducted for child and parent ratings on the PedsQL-Multidimensional Fatigue Scale to plot recovery across domains (General, Cognitive, Sleep/Rest) and Total fatigue, from 1 week to 3 months postinjury. Two-block hierarchical regression analyses were then conducted for parent and child ratings of fatigue at each time point, with age, sex and acute symptoms in block 1 and child and parent mental health variables added to block 2. RESULTS: There was a significant reduction in both child and parent ratings across the 3 months postinjury for all fatigue domains (all p<0.001). For both child and parent fatigue ratings, child mental health was the most significant factor associated with fatigue at all time points. Adding child and parent mental health variables in the second block of the regression substantially increased the variance explained for both child and parent ratings of fatigue. CONCLUSION: Our findings confirm that fatigue improves during the first 3 months postconcussion and highlights the importance of considering child and parent mental health screening when assessing patients with persisting postconcussive symptoms.

Evaluation of the SCAT 5 tool in the assessment of concussion in Para athletes: a Delphi study.

OBJECTIVES: To investigate if the sport concussion assessment tool version 5 (SCAT5) could be suitable for application to Para athletes with a visual impairment, a spinal cord injury, or a limb deficiency. METHODS: A 16-member expert panel performed a Delphi technique protocol. The first round encompassed an open-ended questionnaire, with round 2 onwards being composed of a series of closed-ended statements requiring each expert's opinion using a five-point Likert scale. A predetermined threshold of 66% was used to decide whether agreement had been reached by the panel. RESULTS: The Delphi study resulted in a four-round process. After round 1, 92 initial statements were constructed with 91 statements obtaining the targeted level of agreement by round 4. The expert panellist completion rate of the full four-round process was 94%. In the case of athletes with a suspected concussion with either limb deficiencies or spinal cord injuries, the panel agreed that a baseline assessment would be needed on record is ideal before a modified SCAT5 assessment. With respect to visual impairments, it was conceded that some tests were either difficult, infeasible or should be omitted entirely depending on the type of visual impairment. CONCLUSION: It is proposed that the SCAT5 could be conducted on athletes with limb deficiencies or spinal cord injuries with some minor modifications and by establishing a baseline assessment to form a comparison. However, it cannot be recommended for athletes with visual impairment in its current form. Further research is needed to determine how potential concussions could be more effectively evaluated in athletes with different impairments.

Where is the research on sport-related concussion in Olympic athletes? A descriptive report and assessment of the impact of access to multidisciplinary care on recovery.

OBJECTIVES: This cohort study reported descriptive statistics in athletes engaged in Summer and Winter Olympic sports who sustained a sport-related concussion (SRC) and assessed the impact of access to multidisciplinary care and injury modifiers on recovery. METHODS: 133 athletes formed two subgroups treated in a Canadian sport institute medical clinic: earlier (≤7 days) and late (≥8 days) access. Descriptive sample characteristics were reported and unrestricted return to sport (RTS) was evaluated based on access groups as well as injury modifiers. Correlations were assessed between time to RTS, history of concussions, the number of specialist consults and initial symptoms. RESULTS: 160 SRC (median age 19.1 years; female=86 (54%); male=74 (46%)) were observed with a median (IQR) RTS duration of 34.0 (21.0-63.0) days. Median days to care access was different in the early (1; nSRC=77) and late (20; nSRC=83) groups, resulting in median (IQR) RTS duration of 26.0 (17.0-38.5) and 45.0 (27.5-84.5) days, respectively (p<0.001). Initial symptoms displayed a meaningful correlation with prognosis in this study (p<0.05), and female athletes (52 days (95% CI 42 to 101)) had longer recovery trajectories than male athletes (39 days (95% CI 31 to 65)) in the late access group (p<0.05). CONCLUSIONS: Olympic athletes in this cohort experienced an RTS time frame of about a month, partly due to limited access to multidisciplinary care and resources. Earlier access to care shortened the RTS delay. Greater initial symptoms and female sex in the late access group were meaningful modifiers of a longer RTS.

Subsequent musculoskeletal injury after concussion in National Football League players.

OBJECTIVE: To assess whether National Football League (NFL) players diagnosed with a concussion have an increased risk of injury after return to football. METHODS: A retrospective cohort study analysed the hazard of subsequent time-loss lower extremity (LEX) or any musculoskeletal injury among NFL players diagnosed with a concussion in 2015-2021 preseason or regular season games compared with: (1) all non-concussed players participating in the same game and (2) players with time-loss upper extremity injury. Cox proportional hazards models were adjusted for number of injuries and concussions in the prior year, player tenure and roster position. Additional models accounted for time lost from participation after concussion. RESULTS: There was no statistical difference in the hazards of LEX injury or any musculoskeletal injury among concussed players compared with non-concussed players, though concussed players had a slightly elevated hazard of injury (LEX injury: HR=1.12, 95% CI 0.90 to 1.41; any musculoskeletal injury: HR=1.08, 95% CI: 0.89 to 1.31). When comparing to players with upper extremity injuries, the hazard of injury for concussed players was not statistically different, though HRs suggested a lower injury risk among concussed players (LEX injury: HR=0.78, 95% CI: 0.60 to 1.02; any musculoskeletal injury: HR=0.82, 95% CI: 0.65 to 1.04). CONCLUSION: We found no statistical difference in the risk of subsequent injury among NFL players returning from concussion compared with non-concussed players in the same game or players returning from upper extremity injury. These results suggest deconditioning or other factors associated with lost participation time may explain subsequent injury risk in concussed players observed in some settings after return to play.

Efficacy of exercise interventions on prevention of sport-related concussion and related outcomes: a systematic review and meta-analysis.

OBJECTIVE: To review the efficacy of exercise interventions on sport-related concussion (SRC) incidence, as well as on linear and rotational head accelerations, and isometric neck strength and to assess reporting completeness of exercise interventions using the Consensus on Exercise Reporting Template (CERT). DESIGN: Systematic review and meta-analysis, according to the Prisma in Exercise, Rehabilitation, Sport medicine and SporTs science guidelines. DATA SOURCES: Six databases (MEDLINE, Embase, CINAHL, Scopus, Web of Science CC and SPORTDiscus) were searched up to 26 June 2023. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised controlled trials (RCTs), cluster RCTs or quasi-experimental studies, evaluating exercise interventions on SRC incidence, linear and rotational head accelerations, and/or isometric neck strength in male and/or female athletes of any age, and/or in a healthy general population. RESULTS: A total of 26 articles were included. A large effect size was observed for resistance training (RT) on isometric neck strength (standardised mean difference (SMD) 0.85; 95% CI 0.57 to 1.13; high-quality evidence). Non-significant effect sizes were observed for neuromuscular warm-up programmes on SRC incidence (risk ratio 0.69; 95% CI 0.39 to 1.23; low-quality evidence), or for RT on linear head acceleration (SMD -0.43; 95% CI -1.26 to 0.40; very low-quality evidence) or rotational head acceleration (SMD 0.08; 95% CI -0.61 to 0.77; low-quality evidence). No studies assessed the impact of RT on SRC incidence. CERT scores ranged from 4 to 16 (out of 19) with median score of 11.5 (IQR 9-13). CONCLUSION: RT increases isometric neck strength, but the effect on SRC incidence is unknown. More adequately powered and rigorous trials are needed to evaluate the effect of exercise interventions on SRC incidence, and on linear and rotational head accelerations. Future studies should follow CERT guidelines, as the included interventions were generally not reported in sufficient detail for accurate replication. PROSPERO REGISTRATION NUMBER: CRD42023435033.

Exploring the association between cognitive activity and symptom resolution following concussion in adolescents aged 11-17 years.

OBJECTIVE: As opposed to postconcussion physical activity, the potential influence of cognitive activity on concussion recovery is not well characterised. This study evaluated the intensity and duration of daily cognitive activity reported by adolescents following concussion and examined the associations between these daily cognitive activities and postconcussion symptom duration. METHODS: This study prospectively enrolled adolescents aged 11-17 years with a physician-confirmed concussion diagnosis within 72 hours of injury from the emergency department and affiliated concussion clinics. Participants were followed daily until symptom resolution or a maximum of 45 days postinjury to record their daily cognitive activity (intensity and duration) and postconcussion symptom scores. RESULTS: Participants (n=83) sustained their concussion mostly during sports (84%), had a mean age of 14.2 years, and were primarily male (65%) and white (72%). Participants reported an average of 191 (SD=148), 166 (SD=151) and 38 (SD=61) minutes of low-intensity, moderate-intensity and high-intensity daily cognitive activity postconcussion while still being symptomatic. Every 10 standardised minutes per hour increase in moderate-intensity or high-intensity cognitive activities postconcussion was associated with a 22% greater rate of symptom resolution (adjusted hazard ratio (aHR) 1.22, 95% CI 1.01 to 1.47). Additionally, each extra day's delay in returning to school postconcussion was associated with an 8% lower rate of symptom resolution (aHR 0.92, 95% CI 0.85 to 0.99). CONCLUSION: In adolescents with concussion, more moderate-high intensity cognitive activity is associated with faster symptom resolution, and a delayed return to school is associated with slower symptom resolution. However, these relationships may be bidirectional and do not necessarily imply causality. Randomised controlled trials are needed to determine if exposure to early cognitive activity can promote concussion recovery in adolescents.

Heads up on concussion: Aboriginal and Torres Strait Islander peoples' knowledge and understanding of mild traumatic brain injury.

ISSUE ADDRESSED: Concussion awareness and knowledge among Aboriginal and Torres Strait Islander peoples residing in Perth, Western Australia and factors preventing presentation at a health service for assessment after such an injury. METHODS: Qualitative study with participants aged between 18 and 65 years. Recruitment was by Facebook advertising and snowball sampling. A semi-structured topic yarning guide was used to guide conversations through 1:1, multi-person or group yarns. Yarns were audio-recorded, transcribed and thematically analysed. RESULTS: Twenty-four participants were recruited. A good knowledge of modes of concussion injury was identified in these participants. However, they identified difficulty differentiating this injury from other injuries or medical conditions. Multiple factors contributed to a reluctance to seek assessment and further management of a potential concussion. Multiple strategies to enhance education and presentation for assessment were suggested by participants. CONCLUSIONS: Aboriginal and Torres Strait Islander-owned and led concussion education is the first step in enhancing understanding of this condition. Education must be coupled with improvements in the cultural safety of healthcare services, as without this, patients will continue to fail to present for assessment and management. SO WHAT?: It is recommended that concussion education focuses on the differentiation of concussion as a diagnosis from other injuries. Information regarding where and when to seek medical assessment is recommended, and this must be in a culturally safe environment. Typical recovery and potential sequelae must be explored, in programs led and devised by Aboriginal and Torres Strait Islander peoples engaged with the community for which the education is proposed.

Cognitive performance in older people after mild traumatic brain injury: Trauma effects and other risk factors.

OBJECTIVE: Cognitive symptoms are common in the initial weeks after mTBI, but recovery is generally expected within three months. However, there is limited information about recovery specifically in older age cohorts. Therefore, this study investigated cognitive outcome three months after mTBI in older adults (≥ 65 years) compared to trauma and community age-matched controls and explored risk factors for outcome after traumatic injury. METHODS: Older mTBI patients (n = 40) and older adults with mild traumatic injury but without head injury (n = 66) were compared to a noninjured community control group (n = 47). Cognitive assessment included neuropsychological and computerized tests. Group differences were compared on individual tasks and overall cognitive performances using composite scores. Regression analyses identified predictors of outcome for trauma patients and moderator analyses explored possible interactions of mTBI severity with age and cognition. RESULTS: As well as lower performances in processing speed and memory, both trauma groups had significantly lower performance on composite neuropsychological (d = .557 and .670) and computerized tasks (d = .783 and .824) compared to noninjured controls. Age, education, and history of depression were direct predictors of cognitive performance after mild traumatic injury (with or without head injury). Further moderation analysis demonstrated that mTBI severity (Glasgow Coma Scale < 15) moderated the impact of older age on computerized assessment (ß = -.138). CONCLUSIONS: Three months after mild trauma (regardless of head injury), older people demonstrate lower cognition compared to noninjured peers. However, severity of mTBI (Glasgow Coma Scale < 15) can interact with older age to predict poorer cognitive outcomes.

Management of Psychological Complications Following Mild Traumatic Brain Injury.

PURPOSE OF REVIEW: It has been clear for decades that psychological factors often contribute to mild traumatic brain injury (mTBI) outcome, but an emerging literature has begun to clarify which specific factors are important, when, for whom, and how they impact recovery. This review aims to summarize the contemporary evidence on psychological determinants of recovery from mTBI and its implications for clinical management. RECENT FINDINGS: Comorbid mental health disorders and specific illness beliefs and coping behaviors (e.g., fear avoidance) are associated with worse recovery from mTBI. Proactive assessment and intervention for psychological complications can improve clinical outcomes. Evidence-based treatments for primary mental health disorders are likely also effective for treating mental health disorders after mTBI, and can reduce overall post-concussion symptoms. Broad-spectrum cognitive-behavioral therapy may modestly improve post-concussion symptoms, but tailoring delivery to individual psychological risk factors and/or symptoms may improve its efficacy. Addressing psychological factors in treatments delivered primarily by non-psychologists is a promising and cost-effective approach for enhancing clinical management of mTBI. Recent literature emphasizes a bio-psycho-socio-ecological framework for understanding mTBI recovery and a precision rehabilitation approach to maximize recovery. Integrating psychological principles into rehabilitation and tailoring interventions to specific risk factors may improve clinical management of mTBI.

Unmet Need for Outpatient Occupational Therapy Services Among Veterans With Mild Traumatic Brain Injury in the Veterans Health Administration: The Role of Facility Characteristics.

OBJECTIVE: To investigate whether participation restrictions, an indicator of need for occupational therapy (OT), was associated with outpatient OT utilization in the Veterans Health Administration (VHA) among Veterans with mild traumatic brain injury (mTBI), and whether this relation differs by facility characteristics. DESIGN: In a secondary analysis of national VHA data, we used modified Poisson regression to model OT utilization (yes/no) as a function of participation restrictions (Mayo-Portland Adaptability Inventory Participation Index [M2PI]), facility characteristics, and covariates. Facility characteristics included complexity, geographic region, and self-reported access to specialty care. Covariates included prior OT utilization, sociodemographic factors, injury characteristics, and spatial access (eg, drive time). Interactions estimated whether the relation between participation restrictions and OT utilization differed across facility characteristics. SETTING: Outpatient setting in the VHA. PARTICIPANTS: 8684 Veterans with a clinician-confirmed mTBI who received outpatient VHA care between 2012 and 2020 (N=8684). INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): OT utilization was measured within a year of M2PI administration using VHA administrative data. RESULTS: Many Veterans who did not receive OT reported participation limitations, indicating unmet need for OT (eg, 67% with leisure restrictions). Participation restrictions were associated with increased likelihood of receiving OT (risk ratio [RR]=1.01; 95% confidence interval [CI]=1.006-1.019), suggesting a tendency for Veterans' OT-related needs to be satisfied. However, interactions indicated that this was not the case among Veterans receiving care in lower complexity facilities, and those in the South. Veterans with longer drive times were less likely to receive OT (RR=0.82; 95% CI=0.744-0.904). CONCLUSIONS: Participation restrictions were associated with OT utilization, yet many Veterans with mTBI who may have benefited did not receive such care. Specific barriers to accessing OT (eg, OT practitioner supply) should be investigated. Novel care models can ensure access to OT services among Veterans seeking care at less-resourced and/or geographically distant VHA facilities.

Quality of life and psychological health after mild traumatic brain injury in older people: Three- and six-month follow up.

OBJECTIVES: Examine quality of life (QoL) and psychological health after mild traumatic brain injury (mTBI) in older people (65+ years) at 3- and 6-month follow-up and explore which injury factors predicted QoL. METHODS: mTBI patients were compared to trauma comparison (TC) and community comparison (CC) groups. QoL and psychological health were measured at both timepoints. After accounting for 3-month psychological health, injury severity, neuroimaging, and 3-month neuropsychological performance were assessed as predictors of 6-month QoL. RESULTS: Overall 3-month QoL was lower for mTBI (Cohen's d = 0.938) and TC (Cohen's d = 0.485) groups compared to CCs, but by 6 months only mTBI patients continued to report poorer overall QoL (Cohen's d = 0.577) and physical QoL (Cohen's d = 0.656). Despite group differences, QoL for most (~92%) was within normative limits. 3-month psychological health predicted QoL 6-months postinjury (ß = -.377, 95% CI -.614, -.140) but other proposed risk factors (GCS <15, neuroimaging, 3-month neuropsychological performance) did not uniquely predict QoL. CONCLUSIONS: Older adults following mTBI reported lower QoL up to 6-months postinjury compared to non-injured peers, indicating that mTBI patients were particularly susceptible to ongoing differences in QoL 6-months postinjury.

When should an athlete retire or discontinue participating in contact or collision sports following sport-related concussion? A systematic review.

OBJECTIVE: To systematically review the scientific literature regarding factors to consider when providing advice or guidance to athletes about retirement from contact or collision sport following sport-related concussion (SRC), and to define contraindications to children/adolescent athletes entering or continuing with contact or collision sports after SRC. DATA SOURCES: Medline, Embase, SPORTSDiscus, APA PsycINFO, CINAHL and Cochrane Central Register of Controlled Trials were searched systematically. STUDY ELIGIBILITY CRITERIA: Studies were included if they were (1) original research, (2) reported on SRC as the primary source of injury, (3) evaluated the history, clinical assessment and/or investigation of findings that may preclude participation in sport and (4) evaluated mood disturbance and/or neurocognitive deficits, evidence of structural brain injury or risk factors for increased risk of subsequent SRC or prolonged recovery. RESULTS: Of 4355 articles identified, 93 met the inclusion criteria. None of the included articles directly examined retirement and/or discontinuation from contact or collision sport. Included studies examined factors associated with increased risk of recurrent SRC or prolonged recovery following SRC. In general, these were low-quality cohort studies with heterogeneous results and moderate risk of bias. Higher number and/or severity of symptoms at presentation, sleep disturbance and symptom reproduction with Vestibular Ocular Motor Screen testing were associated with prolonged recovery and history of previous concussion was associated with a risk of further SRC. CONCLUSION: No evidence was identified to support the inclusion of any patient-specific, injury-specific or other factors (eg, imaging findings) as absolute indications for retirement or discontinued participation in contact or collision sport following SRC. PROSPERO REGISTRATION NUMBER: CRD42022155121.

What tests and measures accurately diagnose persisting post-concussive symptoms in children, adolescents and adults following sport-related concussion? A systematic review.

OBJECTIVE: To determine what tests and measures accurately diagnose persisting post-concussive symptoms (PPCS) in children, adolescents and adults following sport-related concussion (SRC). DESIGN: A systematic literature review. DATA SOURCES: MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, CINAHL and SPORTDiscus through March 2022. ELIGIBILITY CRITERIA: Original, empirical, peer-reviewed findings (cohort studies, case-control studies, cross-sectional studies and case series) published in English and focused on SRC. Studies needed to compare individuals with PPCS to a comparison group or their own baseline prior to concussion, on tests or measures potentially affected by concussion or associated with PPCS. RESULTS: Of 3298 records screened, 26 articles were included in the qualitative synthesis, including 1016 participants with concussion and 531 in comparison groups; 7 studies involved adults, 8 involved children and adolescents and 11 spanned both age groups. No studies focused on diagnostic accuracy. Studies were heterogeneous in participant characteristics, definitions of concussion and PPCS, timing of assessment and the tests and measures examined. Some studies found differences between individuals with PPCS and comparison groups or their own pre-injury assessments, but definitive conclusions were not possible because most studies had small convenience samples, cross-sectional designs and were rated high risk of bias. CONCLUSION: The diagnosis of PPCS continues to rely on symptom report, preferably using standardised symptom rating scales. The existing research does not indicate that any other specific tool or measure has satisfactory accuracy for clinical diagnosis. Future research drawing on prospective, longitudinal cohort studies could help inform clinical practice.

Protective equipment in youth ice hockey: are mouthguards and helmet age relevant to concussion risk?

OBJECTIVES: To compare the incidence rates and odds of concussion between youth ice hockey players based on mouthguard use and helmet age. MATERIALS AND METHODS: Within a 5-year longitudinal cohort (2013/2014 to 2017/2018) of male and female ice hockey players (ages 11-18; n=3330 players) in Alberta (Canada), we analysed the relationship of equipment and concussion in both a prospective cohort and nested case (concussion) control (acute musculoskeletal injury) approach. The prospective cohort included baseline assessments documenting reported mouthguard use (yes/sometimes, no use), helmet age (newer/<2 years old, older/≥2 years old) and important covariables (weight, level of play, position of play, concussion history, body checking policy), with weekly player participation throughout the season. The nested case-control component used injury reports to document equipment (mouthguard use, helmet age) and other information (eg, mechanism and type of injury) for the injury event. Multivariable mixed effects negative binomial regression (prospective cohort, incidence rate ratios (IRRs)) and multivariable mixed effects logistic regression (nested case-control, odds ratios (OR)) examined the association between equipment and concussion. RESULTS: Players who reported wearing a mouthguard had a 28% lower concussion rate (IRR=0.72, 95% CI 0.56 to 0.93) and 57% lower odds of concussion (OR=0.43, 95% CI 0.27 to 0.70) compared with non-wearers. There were no associations in the concussion rate (IRR=0.94, 95% CI 0.75 to 1.15) and odds (OR=1.16, 95% CI 0.73 to 1.86) between newer and older helmets. CONCLUSIONS: Wearing a mouthguard was associated with a lower concussion rate and odds. Policy mandating use should be considered in youth ice hockey. More research is needed to identify other helmet characteristics (eg, quality, fit) that could lower concussion risk.

Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport-Amsterdam, October 2022.

For over two decades, the Concussion in Sport Group has held meetings and developed five international statements on concussion in sport. This 6th statement summarises the processes and outcomes of the 6th International Conference on Concussion in Sport held in Amsterdam on 27-30 October 2022 and should be read in conjunction with the (1) methodology paper that outlines the consensus process in detail and (2) 10 systematic reviews that informed the conference outcomes. Over 3½ years, author groups conducted systematic reviews of predetermined priority topics relevant to concussion in sport. The format of the conference, expert panel meetings and workshops to revise or develop new clinical assessment tools, as described in the methodology paper, evolved from previous consensus meetings with several new components. Apart from this consensus statement, the conference process yielded revised tools including the Concussion Recognition Tool-6 (CRT6) and Sport Concussion Assessment Tool-6 (SCAT6, Child SCAT6), as well as a new tool, the Sport Concussion Office Assessment Tool-6 (SCOAT6, Child SCOAT6). This consensus process also integrated new features including a focus on the para athlete, the athlete's perspective, concussion-specific medical ethics and matters related to both athlete retirement and the potential long-term effects of SRC, including neurodegenerative disease. This statement summarises evidence-informed principles of concussion prevention, assessment and management, and emphasises those areas requiring more research.

Clinical recovery from concussion-return to school and sport: a systematic review and meta-analysis.

OBJECTIVE: To define the time frames, measures used and modifying factors influencing recovery, return to school/learn (RTL) and return to sport (RTS) after sport-related concussion (SRC). DESIGN: Systematic review and meta-analysis. DATA SOURCES: 8 databases searched through 22 March 2022. ELIGIBILITY CRITERIA: Studies with diagnosed/suspected SRC and interventions facilitating RTL/RTS or investigating the time and modifying factors for clinical recovery. Outcomes included days until symptom free, days until RTL and days until RTS. We documented study design, population, methodology and results. Risk of bias was evaluated using a modified Scottish Intercollegiate Guidelines Network tool. RESULTS: 278 studies were included (80.6% cohort studies and 92.8% from North America). 7.9% were considered high-quality studies, while 23.0% were considered high risk of bias and inadmissible. The mean days until symptom free was 14.0 days (95% CI: 12.7, 15.4; I2=98.0%). The mean days until RTL was 8.3 (95% CI: 5.6, 11.1; I2=99.3%), with 93% of athletes having a full RTL by 10 days without new academic support. The mean days until RTS was 19.8 days (95% CI: 18.8, 20.7; I2=99.3%), with high heterogeneity between studies. Several measures define and track recovery, with initial symptom burden remaining the strongest predictor of longer days until RTS. Continuing to play and delayed access to healthcare providers were associated with longer recovery. Premorbid and postmorbid factors (eg, depression/anxiety, migraine history) may modify recovery time frames. Though point estimates suggest that female sex or younger age cohorts take longer to recover, the heterogeneity of study designs, outcomes and overlap in CIs with male sex or older age cohorts suggests that all have similar recovery patterns. CONCLUSION: Most athletes have full RTL by 10 days but take twice as long for an RTS. PROSPERO REGISTRATION NUMBER: CRD42020159928.