Recurrent neural network-based acute concussion classifier using raw resting state EEG data.

Concussion is a global health concern. Despite its high prevalence, a sound understanding of the mechanisms underlying this type of diffuse brain injury remains elusive. It is, however, well established that concussions cause significant functional deficits; that children and youths are disproportionately affected and have longer recovery time than adults; and that individuals suffering from a concussion are more prone to experience additional concussions, with each successive injury increasing the risk of long term neurological and mental health complications. Currently, the most significant challenge in concussion management is the lack of objective, clinically- accepted, brain-based approaches for determining whether an athlete has suffered a concussion. Here, we report on our efforts to address this challenge. Specifically, we introduce a deep learning long short-term memory (LSTM)-based recurrent neural network that is able to distinguish between non-concussed and acute post-concussed adolescent athletes using only short (i.e. 90 s long) samples of resting state EEG data as input. The athletes were neither required to perform a specific task nor expected to respond to a stimulus during data collection. The acquired EEG data were neither filtered, cleaned of artefacts, nor subjected to explicit feature extraction. The LSTM network was trained and validated using data from 27 male, adolescent athletes with sports related concussion, benchmarked against 35 non-concussed adolescent athletes. During rigorous testing, the classifier consistently identified concussions with an accuracy of > 90% and achieved an ensemble median Area Under the Receiver Operating Characteristic Curve (ROC/AUC) equal to 0.971. This is the first instance of a high-performing classifier that relies only on easy-to-acquire resting state, raw EEG data. Our concussion classifier represents a promising first step towards the development of an easy-to-use, objective, brain-based, automatic classification of concussion at an individual level.

Classification of Comprehensive Neuro-Ophthalmologic Measures of Postacute Concussion.

Importance: Symptom-based methods of concussion diagnosis in contact sports result in underdiagnosis and repeated head injury exposure, increasing the risk of long-term disability. Measures of neuro-ophthalmologic (NO) function have the potential to serve as objective aids, but their diagnostic utility is unknown. Objective: To identify NO measures that accurately differentiate athletes with and without concussion. Design, Setting, and Participants: This cohort study was conducted among athletes with and without concussion who were aged 17 to 22 years between 2016 and 2017. Eye movements and cognitive function were measured a median of 19 days after injury among patients who had an injury meeting the study definition of concussion while playing a sport (retrospectively selected from a concussion clinic), then compared with a control group of participants without concussion (enrolled from 104 noncontact collegiate athlete volunteers without prior head injury). Data analysis was conducted from November 2019 through May 2020. Exposure: Concussion. Main Outcomes and Measures: Classification accuracy of clinically important discriminator eye-tracking (ET) metrics. Participants' eye movements were evaluated with a 12-minute ET procedure, yielding 42 metrics related to smooth pursuit eye movement (SPEM), saccades, dynamic visual acuity, and reaction time. Clinically important discriminator metrics were defined as those with significantly different group differences and area under the receiver operator characteristic curves (AUROCs) of at least 0.70. Results: A total of 34 participants with concussions (mean [SD] age, 19.7 [2.4] years; 20 [63%] men) and 54 participants without concussions (mean [SD] age, 20.8 [2.2] years; 31 [57%] men) completed the study. Six ET metrics (ie, simple reaction time, discriminate reaction time, discriminate visual reaction speed, choice visual reaction speed, and reaction time on 2 measures of dynamic visual acuity 2) were found to be clinically important; all were measures of reaction time, and none were related to SPEM. Combined, these 6 metrics had an AUROC of 0.90 (95% CI, 0.80-0.99), a sensitivity of 77.8%, and a specificity of 92.6%. The 6 metrics remained significant on sensitivity testing. Conclusions and Relevance: In this study, ET measures of slowed visual reaction time had high classification accuracy for concussion. Accurate, objective measures of NO function have the potential to improve concussion recognition and reduce the disability associated with underdiagnosis.

Developing an Index of Medical Conditions Associated with Outcomes after Moderate-to-Severe Traumatic Brain Injury.

Medical conditions co-occurring with traumatic brain injury (TBI) are associated with outcomes, and comorbidity indices such as Charlson and Elixhauser are used in TBI research, but they are not TBI specific. The purpose of this research was to develop an index or indices of medical conditions, identified in acute care after moderate to severe TBI, that are associated with outcomes at rehabilitation discharge. Using the TBI Model Systems National Database, the International Classification of Diseases, Ninth Revision (ICD-9) and Tenth Revision (ICD-10) codes of 8988 participants were converted to Healthcare Cost and Utilization Project (HCUP) diagnostic categories. Poisson regression models were built predicting Disability Rating Scale and Functional Independence Measure Cognitive and Motor subscale scores from HCUP categories after controlling for demographic and injury characteristics. Unweighted, weighted, and anchored indices based on the outcome models predicted 7.5-14.3% of the variance in the observed outcomes. When the indices were applied to a new validation sample of 1613 cases, however, only 2.6-6.6% of the observed outcomes were predicted. Therefore, no models or indices were recommended for future use, but several study findings are highlighted suggesting the importance and the potential for future research in this area.

Plasma Biomarker Concentrations Associated With Return to Sport Following Sport-Related Concussion in Collegiate Athletes-A Concussion Assessment, Research, and Education (CARE) Consortium Study.

Importance: Identifying plasma biomarkers associated with the amount of time an athlete may need before they return to sport (RTS) following a sport-related concussion (SRC) is important because it may help to improve the health and safety of athletes. Objective: To examine whether plasma biomarkers can differentiate collegiate athletes who RTS in less than 14 days or 14 days or more following SRC. Design, Setting, and Participants: This multicenter prospective diagnostic study, conducted by the National Collegiate Athletics Association-Department of Defense Concussion Assessment, Research, and Education Consortium, included 127 male and female athletes who had sustained an SRC while enrolled at 6 Concussion Assessment, Research, and Education Consortium Advanced Research Core sites as well as 2 partial-Advanced Research Core military service academies. Data were collected between February 2015 and May 2018. Athletes with SRC completed clinical testing and blood collection at preseason (baseline), postinjury (0-21 hours), 24 to 48 hours postinjury, time of symptom resolution, and 7 days after unrestricted RTS. Main Outcomes and Measures: A total of 3 plasma biomarkers (ie, total tau protein, glial fibrillary acidic protein [GFAP], and neurofilament light chain protein [Nf-L]) were measured using an ultrasensitive single molecule array technology and were included in the final analysis. RTS was examined between athletes who took less than 14 days vs those who took 14 days or more to RTS following SRC. Linear mixed models were used to identify significant interactions between period by RTS group. Area under the receiver operating characteristic curve analyses were conducted to examine whether these plasma biomarkers could discriminate between RTS groups. Results: The 127 participants had a mean (SD) age of 18.9 (1.3) years, and 97 (76.4%) were men; 65 (51.2%) took less than 14 days to RTS, and 62 (48.8%) took 14 days or more to RTS. Linear mixed models identified significant associations for both mean (SE) plasma total tau (24-48 hours postinjury, <14 days RTS vs ≥14 days RTS: -0.65 [0.12] pg/mL vs -0.14 [0.14] pg/mL; P = .008) and GFAP (postinjury, 14 days RTS vs ≥14 days RTS: 4.72 [0.12] pg/mL vs 4.39 [0.11] pg/mL; P = .04). Total tau at the time of symptom resolution had acceptable discrimination power (area under the receiver operating characteristic curve, 0.75; 95% CI, 0.63-0.86; P < .001). We also examined a combined plasma biomarker panel that incorporated Nf-L, GFAP, and total tau at each period to discriminate RTS groups. Although the analyses did reach significance at each time period when combined, results indicated that they were poor at distinguishing the groups (area under the receiver operating characteristic curve, <0.7). Conclusions and Relevance: The findings of this study suggest that measures of total tau and GFAP may identify athletes who will require more time to RTS. However, further research is needed to improve our ability to determine recovery following an SRC.

Subtypes of Sport-Related Concussion: a Systematic Review and Meta-cluster Analysis.

OBJECTIVE: Current clinical guidelines provide a unitary approach to manage sport-related concussion (SRC), while heterogeneity in the presentation of symptoms suggests that subtypes of SRC may exist. We systematically reviewed the available evidence on SRC subtypes and associated clinical outcomes. DATA SOURCES: Ovid Medline, Embase, PsycINFO, and SPORTDiscus ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Electronic databases were searched for studies: (i) identifying SRC symptom clusters using classification methodology; or (ii) associating symptom clusters to clinical outcome variables. A total of 6,146 unique studies were identified, of which 75 full texts were independently assessed by two authors for eligibility. A total of 22 articles were included for systematic review. DATA EXTRACTION: Two independent authors performed data extraction and risk of bias analysis using the Cochrane Collaboration tool. DATA SYNTHESIS: Six studies found evidence for existence of SRC symptom clusters. Combining the available literature through Multiple Correspondence Analysis (MCA) provided evidence for the existence of a migraine cluster, a cognitive-emotional cluster, a sleep-emotional cluster, a neurological cluster, and an undefined feelings cluster. Nineteen studies found meaningful associations between SRC symptom clusters and clinical outcomes. Clusters mapping to the migraine cluster were most frequently reported in the literature and were most strongly related to aspects of clinical outcome. CONCLUSIONS: The available literature provides evidence for the existence of at least five subtypes in SRC symptomatology, with clear relevance to clinical outcome. Systematically embedding the differentiation of SRC subtypes into prognosis, clinical management, and intervention strategies may optimize the recovery from SRC.

Concussive Events: Using the Evidence to Guide Physical Therapist Practice.

Concussion (also called mild traumatic brain injury) can occur across the lifespan. Excessive force to the head, either through direct impact or force transmission through the body and neck, is a concussive event. After a concussive event, there can be injury not only to the brain, but also to other structures such as the cervical spine and vestibular system. The clinical practice guideline published in the April 2020 issue of JOSPT outlines the role of physical therapy examination and management after a concussive event. J Orthop Sports Phys Ther 2020;50(4):176-177. doi:10.2519/jospt.2020.0502.

Early versus delayed emergency department presentation following mild Traumatic Brain Injury and the presence of symptom at 1, 4 and 12 weeks in children.

OBJECTIVES: We evaluated the association between timing of presentation and postconcussive symptoms (PCS) at 1, 4 and 12 weeks after injury. METHODS: This was a secondary analysis of a prospective cohort study conducted in nine Canadian paediatric EDs in 2013-2015 (5P study). Participants were children who suffered a head injury within the preceding 48 hours and met Zurich consensus concussion diagnostic criteria. The exposure was the time between head injury and ED presentation. The primary outcome was the presence of PCS at 1 week defined by the presence of at least three symptoms on the Post-Concussion Symptom Inventory (PCSI). Secondary outcomes evaluated PCS at 4 and 12 weeks. Multivariable logistic regression analyses were adjusted for ED PCSI and other potential confounders. RESULTS: There were 3041 patients with a concussion in which timing of the injury was known. 2287 (75%) participants sought care in the first 12 hours, 388 (13%) 12-24 hours after trauma and 366 (12%) between 24 and 48 hours. Compared with children who sought care >24 hours after trauma, children who sought care in the first 12 hours had a significantly lower incidence of PCS at 1 week (OR: 0.55 (95% CI 0.41 to 0.75)) and 4 weeks (OR: 0.74 (95% CI 0.56 to 0.99)) but not at 12 weeks (OR: 0.88 (95% CI 0.63 to 1.23)). CONCLUSIONS: Patients who present early after a concussion appear to have a shorter duration of PCS than those presenting more than 12 hours later. Patients/families should be informed of the higher probability of PCS in children with delayed presentation.

Comparison of Methods for Classifying Persistent Post-Concussive Symptoms in Children.

Pediatric mild traumatic brain injury (pmTBI) has received increased public scrutiny over the past decade, especially regarding children who experience persistent post-concussive symptoms (PPCS). However, several methods for defining PPCS exist in clinical and scientific literature, and even healthy children frequently exhibit non-specific, concussive-like symptoms. Inter-method agreement (six PPCS methods), observed misclassification rates, and other psychometric properties were examined in large cohorts of consecutively recruited adolescent patients with pmTBI (n = 162) 1 week and 4 months post-injury and in age/sex-matched healthy controls (HC; n = 117) at equivalent time intervals. Six published PPCS methods were stratified into Simple Change (e.g., International Statistical Classification of Diseases and Related Health Problems, 10th revision [ICD-10]) and Standardized Change (e.g., reliable change indices) algorithms. Among HC, test-retest reliability was fair to good across the 4-month assessment window, with evidence of bias (i.e., higher symptom ratings) during retrospective relative to other assessments. Misclassification rates among HC were higher (>30%) for Simple Change algorithms, with poor inter-rater reliability of symptom burden across HC and their parents. A 49% spread existed in terms of the proportion of pmTBI patients "diagnosed" with PPCS at 4 months, with superior inter-method agreement among standardized change algorithms. In conclusion, the self-reporting of symptom burden is only modestly reliable in typically developing adolescents over a 4-month period, with additional evidence for systematic bias in both adolescent and parental ratings. Significant variation existed for identifying pmTBI patients who had "recovered" (i.e., those who did not meet individual criteria for PPCS) from concussion across the six definitions, representing a considerable challenge for estimating the true incidence rate of PPCS in published literature. Although relatively straightforward to obtain, current findings question the utility of the most commonly used Simple Change scores for diagnosis of PPCS in clinical settings.

Practical Management: Brief Physical Examination for Sport-Related Concussion in the Outpatient Setting.

This article presents a brief, focused physical examination [PE, the Buffalo Concussion Physical Examination (BCPE)] for sport-related concussion (SRC) to be considered for use in the outpatient setting by sports medicine physicians, pediatricians, and primary-care physicians. This companion paper describes how to perform the PE, which was derived in a separate study presented in this journal. It is envisioned for use at the initial and follow-up outpatient visits both for acute concussions and in patients with prolonged symptoms. A pertinent PE, combined with other assessments, can help identify specific treatment targets in those with persistent symptoms after SRC. The BCPE includes orthostatic vital signs and examinations of the cranial nerves, oculomotor/ophthalmologic, cervical, and vestibular systems. Supplementary tests, including testing for exercise tolerance and neurocognitive function, may be performed if indicated. It is recommended that a PE be performed at the initial visit and every 1 to 2 weeks after SRC. On return of symptoms, cognition, and the PE to baseline, as well as normalization of any supplementary tests, patients can begin a return to play program.

Concussion Guidelines Step 2: Evidence for Subtype Classification.

BACKGROUND: Concussion is a heterogeneous mild traumatic brain injury (mTBI) characterized by a variety of symptoms, clinical presentations, and recovery trajectories. By thematically classifying the most common concussive clinical presentations into concussion subtypes (cognitive, ocular-motor, headache/migraine, vestibular, and anxiety/mood) and associated conditions (cervical strain and sleep disturbance), we derive useful definitions amenable to future targeted treatments. OBJECTIVE: To use evidence-based methodology to characterize the 5 concussion subtypes and 2 associated conditions and report their prevalence in acute concussion patients as compared to baseline or controls within 3 d of injury. METHODS: A multidisciplinary expert workgroup was established to define the most common concussion subtypes and their associated conditions and select clinical questions related to prevalence and recovery. A literature search was conducted from January 1, 1990 to November 1, 2017. Two experts abstracted study characteristics and results independently for each article selected for inclusion. A third expert adjudicated disagreements. Separate meta-analyses were conducted to do the following: 1) examine the prevalence of each subtype/associated condition in concussion patients using a proportion, 2) assess subtype/associated conditions in concussion compared to baseline/uninjured controls using a prevalence ratio, and 3) compare the differences in symptom scores between concussion subtypes and uninjured/baseline controls using a standardized mean difference (SMD). RESULTS: The most prevalent concussion subtypes for pediatric and adult populations were headache/migraine (0.52; 95% CI = 0.37, 0.67) and cognitive (0.40; 95% CI = 0.25, 0.55), respectively. In pediatric patients, the prevalence of the vestibular subtype was also high (0.50; 95% CI = 0.40, 0.60). Adult patients were 4.4, 2.9, and 1.7 times more likely to demonstrate cognitive, vestibular, and anxiety/mood subtypes, respectively, as compared with their controls (P < .05). Children and adults with concussion showed significantly more cognitive symptoms than their respective controls (SMD = 0.66 and 0.24; P < .001). Furthermore, ocular-motor in adult patients (SMD = 0.72; P < .001) and vestibular symptoms in both pediatric and adult patients (SMD = 0.18 and 0.36; P < .05) were significantly worse in concussion patients than in controls. CONCLUSION: Five concussion subtypes with varying prevalence within 3 d following injury are commonly seen clinically and identifiable upon systematic literature review. Sleep disturbance, a concussion-associated condition, is also common. There was insufficient information available for analysis of cervical strain. A comprehensive acute concussion assessment defines and characterizes the injury and, therefore, should incorporate evaluations of all 5 subtypes and associated conditions.

Radiologic common data elements rates in pediatric mild traumatic brain injury.

OBJECTIVE: The nosology for classifying structural MRI findings following pediatric mild traumatic brain injury (pmTBI) remains actively debated. Radiologic common data elements (rCDE) were developed to standardize reporting in research settings. However, some rCDE are more specific to trauma (probable rCDE). Other more recently proposed rCDE have multiple etiologies (possible rCDE), and may therefore be more common in all children. Independent cohorts of patients with pmTBI and controls were therefore recruited from multiple sites (New Mexico and Ohio) to test the dual hypothesis of a higher incidence of probable rCDE (pmTBI > controls) vs similar rates of possible rCDE on structural MRI. METHODS: Patients with subacute pmTBI (n = 287), matched healthy controls (HC; n = 106), and orthopedically injured (OI; n = 71) patients underwent imaging approximately 1 week postinjury and were followed for 3-4 months. RESULTS: Probable rCDE were specific to pmTBI, occurring in 4%-5% of each sample, rates consistent with previous large-scale CT studies. In contrast, prevalence rates for incidental findings and possible rCDE were similar across groups (pmTBI vs OI vs HC). The prevalence of possible rCDE was also the only finding that varied as a function of site. Possible rCDE and incidental findings were not associated with postconcussive symptomatology or quality of life 3-4 months postinjury. CONCLUSION: Collectively, current findings question the trauma-related specificity of certain rCDE, as well how these rCDE are radiologically interpreted. Refinement of rCDE in the context of pmTBI may be warranted, especially as diagnostic schema are evolving to stratify patients with structural MRI abnormalities as having a moderate injury.

Brain Concussion: New Classifications and Current Physiopathological Knowledge of the Disease

The present review paper aims to update the definition and classification of cerebral concussion, highlighting its pathophysiological mechanisms. The high prevalence of cerebral concussion in emergency rooms around the world makes it necessary to know its proper management to avoid its late sequelae, which traditionally compromise cognitive aspects of behavior. New evidence on potential neuroprotective treatments is being investigated.

Direct Oral Anticoagulant Treatment and Mild Traumatic Brain Injury: Risk of Early and Delayed Bleeding and the Severity of Injuries Compared with Vitamin K Antagonists.

BACKGROUND: The risk of intracranial hemorrhage (ICH) in patients taking direct oral anticoagulants (DOACs) after mild traumatic brain injury (MTBI) is unclear. OBJECTIVES: To assess the differences in the risk of developing early, delayed, and comprehensive bleeding after MTBI among patients treated with DOACs as compared with those treated with vitamin K antagonists (VKAs). METHODS: All MTBI patients taking oral anticoagulants in our emergency department between June 2017 and August 2018 were included. All patients on oral anticoagulants underwent immediate cerebral computed tomography (CT) and a second CT scan after 24 h of clinical observation. RESULTS: There were 451 patients enrolled: 268 were on VKAs and 183 on DOACs. Of the DOAC-treated patients, 7.7% (14/183) presented overall intracranial bleeding, compared with 14.9% (40/268) of VKA-treated patients (p = 0.026). Early bleeding was present in 5.5% (10/183) of DOAC-treated patients and in 11.6% (31/268) of VKA-treated patients (p = 0.030). Multivariable analysis showed that VKA therapy (odds ratio [OR] 2.327), high-energy impact (OR 11.229), amnesia (OR 2.814), loss of consciousness (OR 5.286), Glasgow Coma Scale score < 15 (OR 4.719), and the presence of lesion above the clavicles (OR 2.742) were associated with significantly higher risk of global ICH. A nomogram was constructed to predict ICH using these six variables. Discrimination of the nomogram revealed good predictive abilities (area under the receiver operating characteristic curve: 0.817). CONCLUSIONS: DOAC-treated patients seem to have lower risk of posttraumatic intracranial bleeding compared with VKA-treated patients.

Definition, Classification, and Epidemiology of Concussion.

The term "concussion" is often ambiguous for patients and caregivers, and likewise for many practitioners the definition remains imprecise. Our understanding of concussion over the last several years has grown and evolved due to the extensive data that is now being collected, and similarly, our definition of the term should too. While there is now more data and literature becoming available regarding pediatric concussion, it seems that there remains a lack of clarity and agreement about the definition and classification of concussion. This article aims to provide a brief review of the available literature on pediatric concussion definition and classifications, and hopefully present the most recent precise and accepted definition and classification system. Surely the definition of concussion will continue to evolve as new knowledge develops.

Derivation and Initial Validation of Clinical Phenotypes of Children Presenting with Concussion Acutely in the Emergency Department: Latent Class Analysis of a Multi-Center, Prospective Cohort, Observational Study.

The identification of clinical phenotypes may help parse the substantial heterogeneity that characterizes children with concussion. This study used latent class analysis (LCA) to identify discernible phenotypes among children with acute concussion and examine the association between phenotypes and persistent post-concussive symptoms (PPCS) at 4 and 12 weeks post-injury. We conducted LCA of variables representing pre-injury history, clinical presentation, and parent symptom ratings, derived from a prospective cohort, observational study that recruited participants from August 2013 until June 2015 at nine pediatric emergency departments within the Pediatric Emergency Research Canada network. This substudy included 2323 children from the original cohort ages 8.00-17.99 years who had data for at least 80% of all variables included in each LCA. Concussion was defined according to Zurich consensus statement diagnostic criteria. The primary outcome was PPCS at 4 and 12 weeks after enrollment. Participants were 39.5% female and had a mean age of 12.8 years (standard deviation = 2.6). Follow-up was completed by 1980 (85%) at 4 weeks and 1744 (75%) at 12 weeks. LCA identified four groups with discrete pre-injury histories, four groups with discrete clinical presentations, and seven groups with discrete profiles of acute symptoms. Clinical phenotypes based on the profile of group membership across the three LCAs varied significantly in their predicted probability of PPCS at 4 and 12 weeks. The results indicate that children with concussion can be grouped into distinct clinical phenotypes, based on pre-injury history, clinical presentation, and acute symptoms, with markedly different risks of PPCS. With further validation, clinical phenotypes may provide a useful heuristic for clinical assessment and management.

A Data-Driven Approach to Unlikely, Possible, Probable, and Definite Acute Concussion Assessment.

Kutcher and Giza suggested incorporating levels of certainty in concussion diagnosis decisions. These guidelines were based on clinical experience rather than objective data. Therefore, we combined data-driven optimization with predictive modeling to identify which athletes are unlikely to have concussion and to classify remaining athletes as having possible, probable, or definite concussion with diagnostic certainty. We developed and validated our framework using data from the Concussion Assessment, Research, and Education (CARE) Consortium. Acute concussions had assessments at <6 h (n = 1085) and 24-48 h post-injury (n = 1413). Normal performances consisted of assessments at baseline (n = 1635) and the time of unrestricted return to play (n = 1345). We evaluated the distribution of acute concussions and normal performances across risk categories and identified inter-class and intra-class differences in demographics, time-of-injury characteristics, the Standard Assessment of Concussion (SAC), Sport Concussion Assessment Tool (SCAT) symptom assessments, and Balance Error Scoring System (BESS). Our algorithm accurately classified concussions as probable or definite (sensitivity = 91.07-97.40%). Definite and probable concussions had higher SCAT symptom scores than unlikely and possible concussions (p < 0.05). Definite concussions had lower SAC and higher BESS scores (p < 0.05). Baseline to post-injury change scores for the SAC, SCAT symptoms, and BESS were significantly different between acute possible and probable concussions and normal performances (p < 0.05). There were no consistent patterns in demographics across risk categories, although a greater proportion of concussions classified as unlikely were reported immediately compared with definite concussions (p < 0.05). Although clinical interpretation is still needed, our data-driven approach to concussion risk stratification provides a promising step toward evidence-based concussion assessment.

Neurocognitive testing in the emergency department: A potential assessment tool for mild traumatic brain injury.

OBJECTIVE: Despite mild traumatic brain injury (mTBI) accounting for 80% of head injury diagnoses, recognition of individuals at risk of cognitive dysfunction remains a challenge in the acute setting. The objective of this study was to evaluate the feasibility and potential role for computerised cognitive testing as part of a complete ED head injury assessment. METHODS: mTBI patients (n = 36) who incurred a head injury within 24 h of presentation to the ED were compared to trauma controls (n = 20) and healthy controls (n = 20) on tests assessing reaction time, speed and attention, episodic memory, working memory and executive functioning. Testing occurred during their visit to the ED at a mean of 12 h post-injury for mTBI and 9.4 h for trauma controls. These tasks were part of the Cambridge Neuropsychological Test Automated Battery iPad application. Healthy controls were tested in both a quiet environment and the ED to investigate the potential effects of noise and distraction on neurocognitive function. RESULTS: Reaction time was significantly slower in the mTBI group compared to trauma patients (P = 0.015) and healthy controls (P = 0.011), and deficits were also seen in working memory compared to healthy controls (P ≤ 0.001) and in executive functioning (P = 0.021 and P < 0.001) compared to trauma and healthy controls. Performances in the control group did not differ between testing environments. CONCLUSION: Computerised neurocognitive testing in the ED is feasible and can be utilised to detect deficits in cognitive performance in the mTBI population as part of a routine head injury assessment.

Mild traumatic brain injury and concussion: terminology and classification.

Traumatic brain injury (TBI) is a major cause of morbidity and mortality throughout the world. Mild TBI, which is typically defined by Glasgow Coma Scale score ≥13, accounts for the vast majority of all TBIs, particularly in the setting of sports-related injuries. The terms concussion and TBI are often used interchangeably, both in the medical literature and in clinical care of this patient population. However, the lack of clearly defined definitions of these terms often leads to confusion, and this confusion may lead to delayed diagnosis and inconsistent management of affected patients. Here, we review the current terminology and classification of mild TBI and concussion. We will also discuss recent efforts to stratify these injuries into clinically relevant subtypes or profiles that are both diagnostic- and treatment-targeted.

Protocol for the mixed-methods development of a concussion-specific health-related quality of life outcome measure based on the international classification of functioning, disability and health.

INTRODUCTION: Recovery from concussion has traditionally been evaluated by patient-reported symptoms, objective measures such as loss of consciousness, specific dimensions such as depression or fatigue, cognitive status, employment status, level of physical activity and the more complex construct of disability. Increasingly, patient-reported outcome measures of health-related quality of life (HRQOL) are being emphasised as an important end point in patient care, clinical trial and health policy decisions. Currently, no standardised concussion-specific HRQOL outcome measure exists. The process for developing a concussion-specific HRQOL outcome measure based on the international classification of functioning, disability and health is outlined. METHODS AND ANALYSIS: A multistage, patient-centred approach to developing the outcome measure will integrate evidence from systematic reviews, qualitative research and cognitive interviewing into a self-report questionnaire to guide clinical decision-making. The psychometric properties of the questionnaire will be evaluated to assess the inter-rater reliability and construct validity of the measure in individuals with persistent post-concussion symptoms. To date, the systematic review and the clinical expert interviews within the preparatory phase have been completed and work is progressing on the subsequent phases. It is anticipated that the outcome measure will be ready for psychometric testing in September 2018. ETHICS AND DISSEMINATION: Ethical approval was granted by the Ottawa Health Science Network Research Ethics Board (Protocol #20170720-01H) on 31 October 2017 to conduct the patient and clinical expert interviews. Ethical approval for psychometric testing of the outcome measure will be sought by the Ottawa Health Science Network Research Ethics Board in Phase II, after the development of the final HRQOL questionnaire. Results will be disseminated through peer-reviewed journals and professional conferences. PROSPERO REGISTRATION: Phase I systematic review registration number CRD42017075588 (15 June 2017). Phase II systematic review registration number CRD42017075588 (27 September 2017).

The Canadian Pediatric Mild Traumatic Brain Injury Common Data Elements Project: Harmonizing Outcomes to Increase Understanding of Pediatric Concussion.

A critical component for accelerating the clinical uptake of research data in the area of pediatric concussion or mild traumatic brain injury (MTBI) pertains to the establishment and utilization of common databases. The objective of the first phase of our CanPedCDE initiative was to agree upon pediatric common data elements (CDEs) that could best characterize children with MTBI over their recovery period. The selection of CDEs for our framework aimed to balance factors such as the comprehensiveness of outcomes collected, their applicability to diverse settings, as well as the costs associated with their use. Selection began by identifying relevant domains of functioning (e.g., post-concussion symptoms, attention, and balance). Two sources were used to make this process more efficient: 1) the World Health Organization International Classification of Functioning (ICF) Traumatic Brain Injury Core Set, and the U.S. National Institute of Neurological Disorders and Stroke Traumatic Brain Injury Common Data Elements, both of which had already suggested relevant domains to include in TBI research. The process was completed in two phases: 1) using an online survey of experts and 2) through an in-person consensus meeting. Measurement tools were also proposed that were best felt to capture these domains. Forty experts in MTBI in children from multiple health-related perspectives (e.g., emergency medicine, pediatrics, neurosurgery, nursing, physiotherapy, and neuroscience), as well as knowledge users, participated in the selection process. The final list of CDEs included 77 distinct areas of functioning, covering all categories of the ICF model. Outcome measures were attached to each element, when applicable. The CanPedCDE initiative addresses a significant limitation in MTBI research to date and may help both researchers and clinicians to organize and standardize their assessment of children and youth post-MTBI in order to move the field in promising directions.