Diagnostic accuracy and reliability of sideline concussion evaluation: a prospective, case-controlled study in college athletes comparing newer tools and established tests

Multifaceted concussion assessment battery: sensitivity at the expense of specificity?

OBJECTIVES

A multifaceted assessment battery is recommended for testing suspected concussed athletes; however, the individual tests have limitations and potentially may lead to false positive outcomes. Therefore, the purpose of this study was to psychometrically evaluate concussion assessment tools used for intercollegiate student-athletes, with a focus on the time interval between baseline and subsequent assessments.

METHODS

Ninety-two collegiate student-athletes matched between concussion (N = 46. F32/M14) and non-concussion (N = 46, 32F/14 M) completed the standard assessment of concussion, balance error scoring system, symptom questionnaire, and computerized neurocognitive tests at baseline and acutely (<48 h) following a concussion. Test outcomes were compared between time points with three approaches: 1) vs baseline, 2) reliable change scores (RCI), and 3) vs American College of Rehabilitation Medicine (ACRM). Concussion assessment sensitivity, specificity, likelihood ratios, predictive values, and diagnostic odds ratio were calculated. A receiver operator characteristic compared area under the curve (AUC) for the overall battery as well as between academic years.

RESULTS

The sensitivity of the battery was high (78.3-95.7%), but specificity was low to moderate (6.5-52.2%) with comparison to the RCI typically performing best. The three approaches yielded AUC values between 0.51 and 0.63 which is below the discriminatory threshold (0.70) with comparison to RCI performing best. By academic year, Juniors was the only year in which the ROC exceeded the threshold (0.75). The number of tests failed did not improve any AUC values (0.51-0.69) to exceed the threshold.

CONCLUSIONS

The outcomes of this study support the premise that concussion must be evaluated using a comprehensive clinical examination including a variety of assessments to evaluate each clinical domain. Clinicians need to recognize that the multifaceted assessment battery has high sensitivity, but the overall psychometrics do not exceed the threshold for group discrimination and caution must be used in their interpretation.

Smartphone-Based Pupillometry Using Machine Learning for the Diagnosis of Sports-Related Concussion

Background: Quantitative pupillometry has been proposed as an objective means to diagnose acute sports-related concussion (SRC). Objective: To assess the diagnostic accuracy of a smartphone-based quantitative pupillometer in the acute diagnosis of SRC. Methods: Division I college football players had baseline pupillometry including pupillary light reflex (PLR) parameters of maximum resting diameter, minimum diameter after light stimulus, percent change in pupil diameter, latency of pupil constriction onset, mean constriction velocity, maximum constriction velocity, and mean dilation velocity using a smartphone-based app. When an SRC occurred, athletes had the smartphone pupillometry repeated as part of their concussion testing. All combinations of the seven PLR parameters were tested in machine learning binary classification models to determine the optimal combination for differentiating between non-concussed and concussed athletes. Results: 93 football athletes underwent baseline pupillometry testing. Among these athletes, 11 suffered future SRC and had pupillometry recordings repeated at the time of diagnosis. In the machine learning pupillometry analysis that used the synthetic minority oversampling technique to account for the significant class imbalance in our dataset, the best-performing model was a random forest algorithm with the combination of latency, maximum diameter, minimum diameter, mean constriction velocity, and maximum constriction velocity PLR parameters as feature inputs. This model produced 91% overall accuracy, 98% sensitivity, 84.2% specificity, area under the curve (AUC) of 0.91, and an F1 score of 91.6% in differentiating between baseline and SRC recordings. In the machine learning analysis prior to oversampling of our imbalanced dataset, the best-performing model was k-nearest neighbors using latency, maximum diameter, maximum constriction velocity, and mean dilation velocity to produce 82% accuracy, 40% sensitivity, 87% specificity, AUC of 0.64, and F1 score of 24%. Conclusions: Smartphone pupillometry in combination with machine learning may provide fast and objective SRC diagnosis in football athletes.

Introduction of the 'Blue Card' Concussion Policy to Semi-Elite Australian Football: Medical Staff Experiences and Perceptions

Background

The Western Australian Football League (WAFL) introduced a new umpire driven 'blue-card rule' for concussion, but its benefit to the sports medicine team is unknown.

Purpose

To determine the experiences and perceptions of medical staff within the 2022-2023 Men's and Women's WAFL competitions following the introduction of the 'blue-card rule'.

Study Design

Cross-sectional study.

Method

An online survey was delivered through Qualtrics to all WAFL medical staff (doctors, physiotherapists, head trainers). The survey contained four sections (demographics, concussion knowledge, concussion exposure and blue-card perceptions) with closed and multiple-answer questions. Standard methods for reporting descriptive data were applied, including mean ± standard deviation (SD) and proportions (%). Between-group differences were assessed using chi-square tests, and significance was accepted at p <0.05.

Results

Response rate was 48% (n=7 doctors, n=12 physiotherapists, n=12 head trainers). Most staff (70%) did not agree that the 'blue-card rule' was a helpful concussion policy or should remain within the WAFL. Staff also felt umpires are not qualified to identify suspected concussions on-field (67%). Over two-thirds of medical staff feel the Football Commission needs to provide education about concussion policies before the commencement of each season. Only 33% of medical staff felt completely confident in delivering a sideline assessment, and 17% felt completely confident in their diagnostic capabilities. Relationships between medical and other staff were not substantially impacted by the 'blue-card rule'.

Conclusions

Medical staff within the WAFL reported the 'blue-card rule' as an ineffective concussion identification tool and did not support its continued use for future WAFL seasons. Staff suggested that the Football Commission needs to provide more education on concussion policies before the commencement of each season.

Level of Evidence

3.

Testing the Validity and Reliability of a Standardized Virtual Examination for Concussion

Background and Objectives

We determined inter-modality (in-person vs telemedicine examination) and inter-rater agreement for telemedicine assessments (2 different examiners) using the Telemedicine Buffalo Concussion Physical Examination (Tele-BCPE), a standardized concussion examination designed for remote use.

Methods

Patients referred for an initial evaluation for concussion were invited to participate. Participants had a brief initial assessment by the treating neurologist. After a patient granted informed consent to participate in the study, the treating neurologist obtained a concussion-related history before leaving the examination room. Using the Tele-BCPE, 2 virtual examinations in no specific sequence were then performed from nearby rooms by the treating neurologist and another neurologist. After the 2 telemedicine examinations, the treating physician returned to the examination room to perform the in-person examination. Intraclass correlation coefficients (ICC) determined inter-modality validity (in-person vs remote examination by the same examiner) and inter-rater reliability (between remote examinations done by 2 examiners) of overall scores of the Tele-BCPE within the comparison datasets. Cohen's kappa, κ, measured levels of agreement of dichotomous ratings (abnormality present vs absent) on individual components of the Tele-BCPE to determine inter-modality and inter-rater agreement.

Results

For total scores of the Tele-BCPE, both inter-modality agreement (ICC = 0.95 [95% CI 0.86-0.98, p < 0.001]) and inter-rater agreement (ICC = 0.88 [95% CI 0.71-0.95, p < 0.001]) were reliable (ICC >0.70). There was at least substantial inter-modality agreement (κ ≥ 0.61) for 25 of 29 examination elements. For inter-rater agreement (2 telemedicine examinations), there was at least substantial agreement for 8 of 29 examination elements.

Discussion

Our study demonstrates that the Tele-BCPE yielded consistent clinical results, whether conducted in-person or virtually by the same examiner, or when performed virtually by 2 different examiners. The Tele-BCPE is a valid indicator of neurologic examination findings as determined by an in-person concussion assessment. The Tele-BCPE may also be performed with excellent levels of reliability by neurologists with different training and backgrounds in the virtual setting. These findings suggest that a combination of in-person and telemedicine modalities, or involvement of 2 telemedicine examiners for the same patient, can provide consistent concussion assessments across the continuum of care.

Maximal aerobic exercise and acute visual performance in females: Implications for concussion side-line testing

PURPOSE

Many sports-related concussion (SRC) outcomes can be prevented by removing affected athletes and allowing return after full recovery. Diagnosing concussions on the side-line is challenging, as tools often rely on visual performance assessment. Since acute exercise can affect vision, it is vital to determine if exercise can mask potential brain injury if visual performance assessments are used. The aim of this study was to determine the effect of a single bout of maximal aerobic exercise on acute visual performance.

METHODS

Eighty previously sedentary females were randomly assigned to an experimental group (N = 40) or control group (N = 40) and completed an identical visual task test battery. Two weeks later, participants returned to participate in the test battery, with the experimental group doing so immediately following a maximal treadmill exercise protocol.

RESULTS

Significant (P < 0.05) improvements were found in accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, and hand-eye coordination (P < 0.001 for all), but not in visual memory (P = 0.556). All visual tasks, barring visual memory, loaded onto a single factor and approximated the root mean square error of approximation (RMSEA) threshold value (RMSEA = 0.112 [90 %CI: 0.047-0.182]), and a significant large main effect was found on all factors as a universal visual task performance (P < 0.001; d = 1.01).

CONCLUSION

This study shows that exercise can affect performance across multiple, but not all, visual tasks and should be utilised with caution in comprehensive side-line SRC assessments. Visual memory may be more stable to the effects of acute exercise and be considered for inclusion in side-line SRC assessments.

Psychometric Properties of Vestibular and Ocular Measures Used for Concussion Assessments: A Scoping Review

BACKGROUND

Concussions most commonly affect the vestibular and ocular systems. Clinical measures used in the assessment of vestibular and ocular deficits should contain strong psychometric properties so that clinicians can accurately detect abnormality to guide treatment interventions.

OBJECTIVES

The aim of this scoping review was: (1) to identify the measures used to evaluate the vestibular and ocular domains postconcussion and (2) to document the psychometric properties of the measures.

METHODS

Two databases (Medline (Ovid) and Embase) were searched from inception to May 2023. An updated search was completed in January 2024 using the same databases and search terms. Studies were screened and data were extracted independently by 2 reviewers. Measures were categorized into vestibular, ocular, or both (vestibular and ocular) domains, and relevant psychometric properties were documented.

RESULTS

Fifty-two studies were included in this review. 28 studies explored the use of vestibular measures, 12 explored ocular measures, and 12 explored both vestibular and ocular measures or explored the use of vestibulo-ocular reflex measures. Most studies explored the properties associated with balance measures, particularly the balance error scoring system. Diagnostic accuracy (sensitivity and specificity metrics) of the associated measures was the most frequently documented characteristic in the literature.

CONCLUSION

Identification of clinical measures used to evaluate vestibular and ocular deficits postconcussion is needed to understand the evidence supporting their use in practice. Documenting the psychometric properties will allow clinicians and researchers to understand the status of the current literature and support for the use of certain measures in practice in terms of their ability to appropriately detect deficits in people with concussion when deficits are truly present.

Clinical Utility of Ocular Assessments in Sport-Related Concussion: A Scoping Review

Background/objectives: Ocular tools and technologies may be used in the diagnosis of sport-related concussions (SRCs), but their clinical utility can vary. The following study aimed to review the literature pertaining to the reliability and diagnostic accuracy of such assessments. Methods: The preferred reporting items for systematic reviews and meta-analysis (PRISMA) extension for scoping reviews was adhered to. Reference standard reliability (RSR ≥ 0.75) and diagnostic accuracy (RSDA ≥ 0.80) were implemented to aid interpretation. Results: In total, 5223 articles were screened using the PCC acronym (Population, Concept, Context) with 74 included in the final analysis. Assessments included the King-Devick (KD) (n = 34), vestibular-ocular motor screening (VOMs) and/or near point of convergence (NPC) (n = 25), and various alternative tools and technologies (n = 20). The KD met RSR, but RSDA beyond amateur sport was limited. NPC met RSR but did not have RSDA to identify SRCs. The VOMs had conflicting RSR for total score and did not meet RSR in its individual tests. The VOMs total score did perform well in RSDA for SRCs. No alternative tool or technology met both RSR and RSDA. Conclusion: Ocular tools are useful, rapid screening tools but should remain within a multi-modal assessment for SRCs at this time.

Quantitative Pupillometry: Clinical Applications for the Internist

From the time of Galen, examination of the pupillary light reflex has been a standard of care across the continuum of health care. The growing body of evidence overwhelmingly supports the use of quantitative pupillometry over subjective examination with flashlight or penlight. At current time, pupillometers have become standard of care in many hospitals across 6 continents. This review paper provides an overview and rationale for pupillometer use and highlights literature supporting pupillometer-derived measures of the pupillary light reflex in both neurological and non-neurological patients across the health care continuum.

Improving Concussion Education: Do Athletic Trainers' Opinions Match Expert Consensus?

CONTEXT

The National Collegiate Athletic Association and Department of Defense (NCAA-DoD) Mind Matters Challenge created "useful and feasible" consensus recommendations to improve concussion care-seeking behavior in collegiate athletes and military cadets. Given athletic trainers' (ATs') role as providers of concussion education and medical care, it is important to understand if they agree with the expert panel that the recommendations are useful and feasible.

OBJECTIVE

To describe and compare the perceptions of ATs in the secondary school (SS) and collegiate settings of the utility and feasibility of the NCAA-DoD Mind Matters Challenge recommendations on improving concussion education.

DESIGN

Cross-sectional study.

SETTING

Electronic survey.

PATIENTS OR OTHER PARTICIPANTS

Five hundred fifteen (515) ATs (age = 40.7 ± 12.4 years, 53.1% female gender) practicing in the SS (60.6%) or collegiate (38.4%) setting.

MAIN OUTCOME MEASURE(S)

An online survey asked participants about their awareness of the statement followed by 17 pairs of Likert-item questions regarding each recommendation's utility and feasibility with responses ranging from no (1) to yes (9). Mimicking the consensus process, we defined consensus as a mean rating of ≥7.00. We compared utility and feasibility rating responses between SS and collegiate setting participants using Mann-Whitney U tests with α = .05.

RESULTS

Two-thirds (66.6%) of participants were unaware of the consensus statement. Participants felt all recommendations were useful (all means ≥ 7.0); however, 4 recommendations related to collaborating with stakeholders did not meet the feasibility cutoff (mean range = 6.66-6.84). Secondary school ATs rated lower feasibility related to educational content (P value range = .001-.014), providing patient education throughout recovery (P = .002), and promoting peer intervention (P = .019) but higher utility (P = .007) and feasibility (P = .002) for providing parent education than collegiate ATs.

CONCLUSIONS

The NCAA-DoD Mind Matters Challenge recommendations require further dissemination. Athletic trainers rated collaboration with stakeholders as a feasibility barrier. Secondary school ATs require more resources for educational content, messaging, and promoting peer intervention but find educating athletes' parents more useful and feasible than collegiate ATs.

Biofluid, Imaging, Physiological, and Functional Biomarkers of Mild Traumatic Brain Injury and Subconcussive Head Impacts

Post-concussive symptoms are frequently reported by individuals who sustain mild traumatic brain injuries (mTBIs) and subconcussive head impacts, even when evidence of intracranial pathology is lacking. Current strategies used to evaluate head injuries, which primarily rely on self-report, have a limited ability to predict the incidence, severity, and duration of post-concussive symptoms that will develop in an individual patient. In addition, these self-report measures have little association with the underlying mechanisms of pathology that may contribute to persisting symptoms, impeding advancement in precision treatment for TBI. Emerging evidence suggests that biofluid, imaging, physiological, and functional biomarkers associated with mTBI and subconcussive head impacts may address these shortcomings by providing more objective measures of injury severity and underlying pathology. Interest in the use of biomarker data has rapidly accelerated, which is reflected by the recent efforts of organizations such as the National Institute of Neurological Disorders and Stroke and the National Academies of Sciences, Engineering, and Medicine to prioritize the collection of biomarker data during TBI characterization in acute-care settings. Thus, this review aims to describe recent progress in the identification and development of biomarkers of mTBI and subconcussive head impacts and to discuss important considerations for the implementation of these biomarkers in clinical practice.

Diagnosis of Sports-Related Concussion Using Symptom Report or Standardized Assessment of Concussion

Importance

The Sports Concussion Assessment Tool-5 (SCAT5) has been recommended for concussion evaluation and utilizes both a subjective reported symptom grading scale and objective measures of concussion including a cognitive evaluation: the Standardized Assessment of Concussion (SAC). The SAC includes testing for orientation, immediate memory, concentration, and delayed recall; a 10-word list is used to assess immediate memory and delayed recall.

Objective

To determine the diagnostic accuracy of components of the SCAT5 and to provide a framework for clinical interpretation.

Design, Setting, and Participants

This prospective case-control study of National Collegiate Athletic Association Division I athletes from any sport was conducted from July 2020 to December 2022 at 4 universities. Athletes completed baseline SCAT5 testing using the 10-word list. When an athlete presented acutely with suspected concussion (sideline or within 2 days), the tests were repeated. If a concussion was diagnosed, a control athlete underwent the same tests. Controls were identified and matched on comorbid conditions, sex and gender, sport, season, and baseline scores. Data analysis was conducted from August to October 2023.

Main Outcomes and Measures

The primary outcomes were area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive and negative predictive value, and test-retest reliability of the symptom score; symptom severity score; the total SAC score; and the orientation, immediate memory, concentration, and delayed memory subcomponent scores on the SCAT5 compared with clinical diagnosis of concussion.

Results

Baseline and postinjury data were collected on 92 athletes with concussion and 92 matched control athletes (96 men [52%] and 88 women [48%]; 110 who played a sport other than football [59%]). Diagnostic utility was considered excellent for symptom score (AUC, 0.93; 95% CI, 0.89-0.96) and symptom severity score (AUC, 0.94; 95% CI, 0.90-0.97). An increase of 2 points on the symptom score was associated with a sensitivity of 86% (95% CI, 78%-92%), specificity of 80% (95% CI, 70%-87I%), and positive predictive value of 81% (95% CI, 72%-88%). The total SAC score had poor to fair diagnostic utility (AUC, 0.70; 95% CI, 0.63-0.77); however, 41 athletes with concussion (45%) had a total SAC score at or above their baseline score (ie, within normal limits). The diagnostic utility was poor to fair for immediate memory (AUC, 0.68, 95%CI, 0.61-0.75) and delayed recall (AUC, 0.69; 95% CI, 0.62-0.77) and not useful for orientation (AUC, 0.49; 95% CI, 0.43-0.56) and concentration (AUC, 0.52 95% CI, 0.44-0.61). Test-retest reliability was fair for total SAC and poor for immediate memory and delayed recall, orientation, and concentration.

Conclusions and Relevance

In this case-control study of the diagnostic accuracy of reported symptoms and the SAC, reported symptoms were the most accurate indicator of concussion while the 10-word SAC had limited sensitivity. These findings suggest that understanding the properties of the SAC is important when making the diagnosis of concussion.

Use of the concussion check protocol for concussion assessment in a female soccer team over two consecutive seasons in New Zealand

AIM

Address deficiencies in access to sports sideline medical care by using a Concussion Check Protocol (CCP) for non-medically-trained people.

METHOD

A prospective observational cohort study was undertaken on a single amateur female club-based soccer team over two consecutive years in New Zealand utilising a non-medically trained support person termed a Safety officer. CCP is an extension of the King-Devick test with features such as warning signs and symptoms of concussion built into the application. All players suspected of having a potential concussive injury were tested on the match sideline.

RESULTS

The study overall incidence of match-related concussions was 20.8 (95% CI: 11.8 to 36.6) per 1000 match-hrs, with mean missed-match duration of 31 (95% CI: 27.9 to 34.1) days. Twelve players over the study had a significantly slower post-injury KD (49.9 [44.3 to 64.1]s; χ2(1) = 11.0; p = 0.0009; z = -2.9; p = 0.0033; d = 0.30) and/or reported symptoms, compared with their own baseline (47.2 [44.3 to 64.1]s). CCP had an overall sensitivity of 100% (95% CI: 73.5% to 100.0%), specificity of 100% (95% CI: 69.2% to 100.0%) and positive predictive value (PPV) of 100% (84.6% to 100.0%).

CONCLUSION

Sideline use of CCP was undertaken successfully by non-medically trained people and provided a reliable platform for concussion identification.

Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review

OBJECTIVES

To systematically review the scientific literature regarding the acute assessment of sport-related concussion (SRC) and provide recommendations for improving the Sport Concussion Assessment Tool (SCAT6).

DATA SOURCES

Systematic searches of seven databases from 2001 to 2022 using key words and controlled vocabulary relevant to concussion, sports, SCAT, and acute evaluation.

ELIGIBILITY CRITERIA

(1) Original research articles, cohort studies, case-control studies, and case series with a sample of >10; (2) ≥80% SRC; and (3) studies using a screening tool/technology to assess SRC acutely (<7 days), and/or studies containing psychometric/normative data for common tools used to assess SRC.

DATA EXTRACTION

Separate reviews were conducted involving six subdomains: Cognition, Balance/Postural Stability, Oculomotor/Cervical/Vestibular, Emerging Technologies, and Neurological Examination/Autonomic Dysfunction. Paediatric/Child studies were included in each subdomain. Risk of Bias and study quality were rated by coauthors using a modified SIGN (Scottish Intercollegiate Guidelines Network) tool.

RESULTS

Out of 12 192 articles screened, 612 were included (189 normative data and 423 SRC assessment studies). Of these, 183 focused on cognition, 126 balance/postural stability, 76 oculomotor/cervical/vestibular, 142 emerging technologies, 13 neurological examination/autonomic dysfunction, and 23 paediatric/child SCAT. The SCAT discriminates between concussed and non-concussed athletes within 72 hours of injury with diminishing utility up to 7 days post injury. Ceiling effects were apparent on the 5-word list learning and concentration subtests. More challenging tests, including the 10-word list, were recommended. Test-retest data revealed limitations in temporal stability. Studies primarily originated in North America with scant data on children.

CONCLUSION

Support exists for using the SCAT within the acute phase of injury. Maximal utility occurs within the first 72 hours and then diminishes up to 7 days after injury. The SCAT has limited utility as a return to play tool beyond 7 days. Empirical data are limited in pre-adolescents, women, sport type, geographical and culturally diverse populations and para athletes.

PROSPERO REGISTRATION NUMBER

CRD42020154787.

Evolving the SCAT5 for Ruling Out Higher-Severity Traumatic Brain Injuries-Can Decision Rules Developed for Emergency Settings Help?

BACKGROUND: Decision rules (eg, Canadian computed tomography head rule [CCHR] for adults and Pediatric Emergency Care Applied Research Network [PECARN] rule for children/adolescents) are used in emergency settings (emergency room [ER] rules) to assess traumatic brain injuries (TBIs). The rules have a high-sensitivity and near-perfect negative predictive value that help to rule out more severe TBI. CLINICAL QUESTION: Which criteria should be added to the Sport Concussion Assessment Tool 5 (SCAT5) to reach the sensitivity of the ER rules and improve the utility of the SCAT5 for screening for higher-severity head and brain injuries? KEY RESULTS: We performed a comparative analysis of the SCAT5 with the CCHR and PECARN rules. We compared the presence (yes or no) and comparative "face value" sensitivity (lower, identical, or higher) of the SCAT5 criteria to the ER rules criteria. Loss of consciousness, vomiting, severe/increasing headache, and seizure are SCAT "red flags" with similar or higher sensitivity compared to ER rules criteria. Five criteria had lower sensitivity or were absent from the SCAT. Emergency room rules include any abnormality on the Glasgow Coma Scale (GCS<15), but only a "deterioration of the state of consciousness" is considered a "red flag" in the SCAT5. Persistent retrograde amnesia for more than 30 minutes, age>65, severity of the mechanism of injury, and signs of skull fractures are not mentioned in the SCAT5. CLINICAL APPLICATION: We identified 5 criteria that could inform the evolution the SCAT5 to improve its ability to rule out more severe TBI in a sideline assessment context. J Orthop Sports Phys Ther 2023;53(3):113-119. Epub: 9 December 2022. doi:10.2519/jospt.2022.11301.

Traumatic brain injury: progress and challenges in prevention, clinical care, and research

Traumatic brain injury (TBI) has the highest incidence of all common neurological disorders, and poses a substantial public health burden. TBI is increasingly documented not only as an acute condition but also as a chronic disease with long-term consequences, including an increased risk of late-onset neurodegeneration. The first Lancet Neurology Commission on TBI, published in 2017, called for a concerted effort to tackle the global health problem posed by TBI. Since then, funding agencies have supported research both in high-income countries (HICs) and in low-income and middle-income countries (LMICs). In November 2020, the World Health Assembly, the decision-making body of WHO, passed resolution WHA73.10 for global actions on epilepsy and other neurological disorders, and WHO launched the Decade for Action on Road Safety plan in 2021. New knowledge has been generated by large observational studies, including those conducted under the umbrella of the International Traumatic Brain Injury Research (InTBIR) initiative, established as a collaboration of funding agencies in 2011. InTBIR has also provided a huge stimulus to collaborative research in TBI and has facilitated participation of global partners. The return on investment has been high, but many needs of patients with TBI remain unaddressed. This update to the 2017 Commission presents advances and discusses persisting and new challenges in prevention, clinical care, and research.

In LMICs, the occurrence of TBI is driven by road traffic incidents, often involving vulnerable road users such as motorcyclists and pedestrians. In HICs, most TBI is caused by falls, particularly in older people (aged ≥65 years), who often have comorbidities. Risk factors such as frailty and alcohol misuse provide opportunities for targeted prevention actions. Little evidence exists to inform treatment of older patients, who have been commonly excluded from past clinical trials—consequently, appropriate evidence is urgently required. Although increasing age is associated with worse outcomes from TBI, age should not dictate limitations in therapy. However, patients injured by low-energy falls (who are mostly older people) are about 50% less likely to receive critical care or emergency interventions, compared with those injured by high-energy mechanisms, such as road traffic incidents.

Mild TBI, defined as a Glasgow Coma sum score of 13–15, comprises most of the TBI cases (over 90%) presenting to hospital. Around 50% of adult patients with mild TBI presenting to hospital do not recover to pre-TBI levels of health by 6 months after their injury. Fewer than 10% of patients discharged after presenting to an emergency department for TBI in Europe currently receive follow-up. Structured follow-up after mild TBI should be considered good practice, and urgent research is needed to identify which patients with mild TBI are at risk for incomplete recovery.

The selection of patients for CT is an important triage decision in mild TBI since it allows early identification of lesions that can trigger hospital admission or life-saving surgery. Current decision making for deciding on CT is inefficient, with 90–95% of scanned patients showing no intracranial injury but being subjected to radiation risks. InTBIR studies have shown that measurement of blood-based biomarkers adds value to previously proposed clinical decision rules, holding the potential to improve efficiency while reducing radiation exposure. Increased concentrations of biomarkers in the blood of patients with a normal presentation CT scan suggest structural brain damage, which is seen on MR scanning in up to 30% of patients with mild TBI. Advanced MRI, including diffusion tensor imaging and volumetric analyses, can identify additional injuries not detectable by visual inspection of standard clinical MR images. Thus, the absence of CT abnormalities does not exclude structural damage—an observation relevant to litigation procedures, to management of mild TBI, and when CT scans are insufficient to explain the severity of the clinical condition.

Although blood-based protein biomarkers have been shown to have important roles in the evaluation of TBI, most available assays are for research use only. To date, there is only one vendor of such assays with regulatory clearance in Europe and the USA with an indication to rule out the need for CT imaging for patients with suspected TBI. Regulatory clearance is provided for a combination of biomarkers, although evidence is accumulating that a single biomarker can perform as well as a combination. Additional biomarkers and more clinical-use platforms are on the horizon, but cross-platform harmonisation of results is needed. Health-care efficiency would benefit from diversity in providers.

In the intensive care setting, automated analysis of blood pressure and intracranial pressure with calculation of derived parameters can help individualise management of TBI. Interest in the identification of subgroups of patients who might benefit more from some specific therapeutic approaches than others represents a welcome shift towards precision medicine. Comparative-effectiveness research to identify best practice has delivered on expectations for providing evidence in support of best practices, both in adult and paediatric patients with TBI.

Progress has also been made in improving outcome assessment after TBI. Key instruments have been translated into up to 20 languages and linguistically validated, and are now internationally available for clinical and research use. TBI affects multiple domains of functioning, and outcomes are affected by personal characteristics and life-course events, consistent with a multifactorial bio-psycho-socio-ecological model of TBI, as presented in the US National Academies of Sciences, Engineering, and Medicine (NASEM) 2022 report. Multidimensional assessment is desirable and might be best based on measurement of global functional impairment. More work is required to develop and implement recommendations for multidimensional assessment. Prediction of outcome is relevant to patients and their families, and can facilitate the benchmarking of quality of care. InTBIR studies have identified new building blocks (eg, blood biomarkers and quantitative CT analysis) to refine existing prognostic models. Further improvement in prognostication could come from MRI, genetics, and the integration of dynamic changes in patient status after presentation.

Neurotrauma researchers traditionally seek translation of their research findings through publications, clinical guidelines, and industry collaborations. However, to effectively impact clinical care and outcome, interactions are also needed with research funders, regulators, and policy makers, and partnership with patient organisations. Such interactions are increasingly taking place, with exemplars including interactions with the All Party Parliamentary Group on Acquired Brain Injury in the UK, the production of the NASEM report in the USA, and interactions with the US Food and Drug Administration. More interactions should be encouraged, and future discussions with regulators should include debates around consent from patients with acute mental incapacity and data sharing. Data sharing is strongly advocated by funding agencies. From January 2023, the US National Institutes of Health will require upload of research data into public repositories, but the EU requires data controllers to safeguard data security and privacy regulation. The tension between open data-sharing and adherence to privacy regulation could be resolved by cross-dataset analyses on federated platforms, with the data remaining at their original safe location. Tools already exist for conventional statistical analyses on federated platforms, however federated machine learning requires further development. Support for further development of federated platforms, and neuroinformatics more generally, should be a priority.

This update to the 2017 Commission presents new insights and challenges across a range of topics around TBI: epidemiology and prevention (section 1 ); system of care (section 2 ); clinical management (section 3 ); characterisation of TBI (section 4 ); outcome assessment (section 5 ); prognosis (Section 6 ); and new directions for acquiring and implementing evidence (section 7 ). Table 1 summarises key messages from this Commission and proposes recommendations for the way forward to advance research and clinical management of TBI.

An investigation into the measurement properties of the King-Devick Eye Tracking system

Objectives

Eye tracking has been gaining increasing attention as a possible assessment and monitoring tool for concussion. The King-Devick test (K-DT) was expanded to include an infrared video-oculography-based eye tracker (K-D ET). Therefore, the aim was to provide evidence on the reliability of the K-D ET system under an exercise condition.

Methods

Participants (N = 61; 26 male, 35 female; age range 19-25) were allocated to an exercise or sedentary group. Both groups completed a baseline K-D ET measurement and then either two 10-min exercise or sedentary interventions with repeated K-D ET measurements between interventions.

Results

The test-retest reliability of the K-D ET ranged from good to excellent for the different variables measured. The mean ± SD of the differences for the total number of saccades was 1.04 ± 4.01 and there was an observable difference (p = 0.005) in the trial number. There were no observable differences for the intervention (p = 0.768), gender (p = 0.121) and trial (p = 0.777) for average saccade’s velocity. The mean ± SD of the difference of the total fixations before and after intervention across both trials was 1.04 ± 3.63 and there was an observable difference in the trial number (p = 0.025). The mean ± SD of the differences for the Inter-Saccadic Interval and the fixation polyarea before and after intervention across both trials were 1.86 ± 22.99 msec and 0.51 ± 59.11 mm2 and no observable differences for the intervention, gender and trial.

Conclusion

The results provide evidence on the reliability of the K-D ET, and the eye-tracking components and demonstrate the relationship between completion time and other variables of the K-D ET system. This is vital as the use of the K-DT may be increasing and the combination of the K-DT and eye tracking as one single package highlights the need to specifically measure the reliability of this combined unit.