Sub-symptom threshold aerobic exercise for patients with persisting post-concussion symptoms and exercise intolerance after mild traumatic brain injury - a study protocol with a nested feasibility study for a randomized controlled trial.

BACKGROUND: Persistent post-concussion symptoms (PPCS) affect between 34 and 46% after a mild traumatic brain injury (mTBI). Many also experience exercise intolerance. Sub-symptom threshold aerobic exercise, SSTAE (exercise at an intensity level that does not increase symptoms) is proposed as a treatment to both reduce the symptom burden and increase the exercise tolerance after the injury. It is unclear if this also applies in a more chronic phase after mTBI. MAIN PURPOSE: The main purpose of this study is to evaluate whether SSTAE in addition to ordinary rehabilitation will lead to clinically meaningful improvement of symptom burden, normalize exercise tolerance, increase physical activity, improve health-related quality of life, and reduce patient-specific activity limitations compared to a control group that only receives ordinary rehabilitation. DESIGN: Randomized, controlled, single-blind parallel-group study with three measurement times; T0 at baseline, T1 after the intervention and T2 six months after T1. METHODS: Patients between the ages of 18 and 60 with exercise intolerance and persistent PPCS (> 3 months) will be recruited to the study and randomized to two groups. All patients will receive follow-up at the outpatient TBI clinic. The intervention group will in addition receive SSTAE for 12 weeks with exercise diaries and a retest every 3 weeks for optimal dosage and progression. The Rivermead post-concussion symptoms questionnaire will be the main outcome measure. The secondary outcome measure will be a test of exercise tolerance-the Buffalo Concussion Treadmill Test. Other outcome measures include the patient-specific functional scale that measures patient-specific activity limitations, as well as outcome measures for diagnosis-specific health-related quality of life, anxiety and depression, specific symptoms such as dizziness, headache and fatigue, and physical activity. DISCUSSION: This study will add knowledge about the effect of SSTAE and whether it should be implemented in rehabilitation for the adult population with persistent PPCS after mTBI. The nested feasibility trial showed that the SSTAE intervention was safe and that the study procedures and delivery of the intervention overall were feasible. However, minor amendments to the study protocol were made prior to the commencement of the RCT. TRIAL REGISTRATION: Clinical Trials.gov, NCT05086419. Registered on September 5th, 2021.

Post-concussion symptoms 1-year after traumatic brain injury: using the Rivermead Post-concussion Questionnaire to identify predictors of severity.

BACKGROUND: Patients who suffer traumatic brain injury (TBI) often experience a constellation of physical, cognitive, and emotional/behavioral symptoms called "post-concussion symptoms" and subsequent long-term disability. This study aimed to investigate the incidence of persistent post-concussion symptoms and possible predictors of long-term disability focusing on demographic, injury, and psychological factors. It was hoped to identify groups at high risk. METHODS: A prospective cohort of 1322 individuals admitted with TBI were assessed in a specialist neurorehabilitation clinic at 10 weeks and 1-year post injury between August 2011 and July 2015. The outcome (post-concussion symptoms) was measured using the Rivermead Post-concussion Questionnaire (RPQ) at 1-year post injury. RESULTS: At 1 yr, 1131 individuals were identified (>90% follow-up). Over 20% exhibited moderate or severe symptom levels on RPQ. A linear regression model showed that previous psychiatric history, lower Glasgow Coma Scale (GCS), severe CT abnormalities, injury caused by assault, pre-injury unemployment, and inability to return to work at 6 weeks post-injury were associated with worse symptoms at 1 yr. The adjusted R2 of the model was 25.1%. CONCLUSION: These findings confirm the high incidence of post-concussion symptoms at 1 yr and identify certain associated features that increase risk. This may allow targeting of certain groups, e.g., return to work or victims of assault.

Models for Treating Post-traumatic Headache.

PURPOSE OF REVIEW: To discuss the treatment of post-traumatic headache (PTH) and how to choose pharmacotherapy based upon known pathophysiology. RECENT FINDINGS: Preclinical models of traumatic brain injury are finally revealing some of the mechanisms of PTH, including the significant role that inflammatory neuropeptides like calcitonin gene-related peptide (CGRP) play in the initiation and persistence of symptoms. To effectively treat post-traumatic headache (PTH), one needs to understand the pathophysiology behind the initiation and persistence of symptoms. Recent animal models are starting to elucidate these mechanisms, but effective treatment will also likely rely on the identification of patients who are most at risk for persistent PTH. Trials of early, targeted therapy for at-risk patients will be needed to validate these hypotheses. Additionally, high powered clinical trials are lacking in the field of persistent PTH for medications that are known to be effective in primary headache disorders. Effective treatment for persistent PTH also requires understanding how headache interacts with the complex nature of persistent post-concussion symptoms, as this disease often necessitates a multi-disciplinary approach. Regardless, with the knowledge gained by new PTH models cited in this paper, and an increasing availability of novel headache medications, more effective treatment models are on the horizon.

Post-concussion symptoms three months after mild-to-moderate TBI: characteristics of sick-listed patients referred to specialized treatment and consequences of intracranial injury.

Objective: To present pre-injury, injury-related, work-related and post-injury characteristics, and to compare patients with and without traumatic intracranial abnormalities, in a treatment-seeking sample with persistent post-concussion symptoms (PPCS) after mild-to-moderate TBI.Methods: Cross-sectional design in the context of a specialized TBI outpatient clinic. Eligible patients were aged 18-60 years, employed ≥ 50% at time of injury, and sick listed ≥ 50% at inclusion due to PPCS. Data were collected 8-12 weeks after injury through review of medical records, semi-structured interviews, questionnaires, and neuropsychological screening.Results: The study included 116 patients, of whom 60% were women, and predominantly white-collar workers in full-time positions. Ninety-four percent had a mild TBI, and 23% had intracranial abnormalities. The full sample reported high somatic, emotional, and cognitive symptom burden, and decreased health-related quality of life. Patients with normal CT/MRI results reported higher overall symptom burden, while patients with intracranial abnormalities had worse memory function.Conclusion: Injury severity and traumatic intracranial radiological findings should not be the sole ground for planning of rehabilitation service provision in patients with PPCS, as subjective complaints do not necessarily co-vary with these variables.

Certified Athletic Trainers' Use of Cervical Clinical Testing in the Diagnosis and Management of Sports-Related Concussion.

CONTEXT: Despite evidence implicating cervicogenic symptoms in the development of persistent postconcussion symptoms, factors that influence utilization of cervical clinical tests to identify cervicogenic symptoms following concussion are poorly understood. OBJECTIVE: Explore barriers to the utilization of cervical clinical testing in multifaceted concussion evaluation. DESIGN: Cross-sectional. SETTING: Online survey. PATIENTS OR OTHER PARTICIPANTS: A total of 122 athletic trainers (AT) (age = 42.6 [6.4] y; female = 51.6%; 52% >10 y of clinical practice; 68% master's degree or greater; 35% treated a minimum of 15 concussions/y). MAIN OUTCOME MEASURE(S): Perceived importance, clinical experience, number of concussions treated, utilization of cervical clinical tests following nonspecific cervical pathology and following concussion, comfort with cervical treatment modalities following a concussion, and recommendation for cervical-specific therapy to treat persistent postconcussion symptoms. RESULTS: Ordinal logistic regression revealed perceived importance had the strongest positive impact on AT's likelihood of high utilization of cervical clinical testing following concussion (95% CI, .17 to .99; P = .005), while clinical experience (95% CI, -.43 to .29; P = .71) and number of concussions treated/y (95% CI, -.21 to .31; P = .71) had no bearing. Moreover, low comfort with cervical treatments following a concussion (95% CI, -2.86 to -.26; P = .018) and low utilization of cervical clinical testing following nonspecific cervical pathology (95% CI, -7.01 to -3.39; P ≤ .001) had a strong positive impact on high utilization of cervical clinical testing following concussion. Two logistic regression models demonstrated how recommendations for cervical-specific therapy in persistent post-concussion symptom patients could be predicted based on (1) cervical test utilization and (2) perceptions and clinical experience with 79% and 78%, respectively. CONCLUSIONS: Perceived importance played a major role in utilization of cervical clinical test following concussion. ATs who utilized common cervical treatments when dealing with non-concussive injuries were more likely to utilize those same treatments to treat comorbid cervical pathology following a concussion.

Identifying the concepts contained within health-related quality of life outcome measures in concussion research using the International Classification of Functioning, Disability, and Health as a reference: a systematic review.

PURPOSE: To identify the concepts contained within health-related quality of life (HRQOL) outcome measures used in concussion-specific research using the International Classification of Functioning, Disability, and Health (ICF) as a reference. METHODS: Eight electronic databases were searched from January 1, 1992 to March 12, 2017. Gray literature was searched, reference lists scanned, and relevant journals hand-searched. Agreement for inclusion was reached by consensus by two reviewers. A standardized data extraction tool was used to document study design, population, and key findings. Questionnaire items were linked as concepts to the corresponding second-level category of the ICF. Quality of studies was not assessed, as review was exploratory. RESULTS: Five outcome measures met the inclusion criteria, including the Perceived Quality of Life Scale, EuroQoL-5 dimensions, Quality of Life after Brain Injury, WHOQOL-100, and WHOQOL-BREF. A total of 373 concepts were extracted. 34 questions were linked to activities and participation (50.7%), 16 questions (23.9%) referred to body functions, and 17 questions (25.4%) were related to the environment. CONCLUSIONS: The wide range of concepts covered by different outcome measures demonstrates the complexity of recovery post-concussion and a lack of universal agreement in terms of what should be measured in this population. A working conceptual model of HRQOL post-concussion is proposed. Registration Prospero #CRD42017068241 (June 15, 2017).

CARE4Kids Study: Endophenotypes of Persistent Post-Concussive Symptoms in Adolescents: Study Rationale and Protocol.

Treatment of youth concussion during the acute phase continues to evolve, and this has led to the emergence of guidelines to direct care. While symptoms after concussion typically resolve in 14-28 days, a portion (∼20%) of adolescents endorse persistent post-concussive symptoms (PPCS) beyond normal resolution. This report outlines a study implemented in response to the National Institute of Neurological Diseases and Stroke call for the development and initial clinical validation of objective biological measures to predict risk of PPCS in adolescents. We describe our plans for recruitment of a Development cohort of 11- to 17-year-old youth with concussion, and collection of autonomic, neurocognitive, biofluid, and imaging biomarkers. The most promising of these measures will then be validated in a separate Validation cohort of youth with concussion, and a final, clinically useful algorithm will be developed and disseminated. Upon completion of this study, we will have generated a battery of measures predictive of high risk for PPCS, which will allow for identification and testing of interventions to prevent PPCS in the most high-risk youth.

Widespread White Matter Abnormalities in Concussed Athletes Detected by 7T Diffusion Magnetic Resonance Imaging.

Sports-related concussions may cause white matter injuries and persistent post-concussive symptoms (PPCS). We hypothesized that athletes with PPCS would have neurocognitive impairments and white matter abnormalities that could be revealed by advanced neuroimaging using ultra-high field strength diffusion tensor (DTI) and diffusion kurtosis (DKI) imaging metrics and cerebrospinal fluid (CSF) biomarkers. A cohort of athletes with PPCS severity limiting the ability to work/study and participate in sport school and/or social activities for ≥6 months completed 7T magnetic resonance imaging (MRI) (morphological T1-weighed volumetry, DTI and DKI), extensive neuropsychological testing, symptom rating, and CSF biomarker sampling. Twenty-two athletes with PPCS and 22 controls were included. Concussed athletes performed below norms and significantly lower than controls on all but one of the psychometric neuropsychology tests. Supratentorial white and gray matter, as well as hippocampal volumes did not differ between concussed athletes and controls. However, of the 72 examined white matter tracts, 16% of DTI and 35% of DKI metrics (in total 28%) were significantly different between concussed athletes and controls. DKI fractional anisotropy and axial kurtosis were increased, and DKI radial diffusivity and radial kurtosis decreased in concussed athletes when compared with controls. CSF neurofilament light (NfL; an axonal injury marker), although not glial fibrillary acidic protein, correlated with several diffusion metrics. In this first 7T DTI and DKI study investigating PPCS, widespread microstructural alterations were observed in the white matter, correlating with CSF markers of axonal injury. More white matter changes were observed using DKI than using DTI. These white matter alterations may indicate persistent pathophysiological processes following concussion in sport.

External Validation of the Post-Concussion Symptoms Rule for Predicting Mild Traumatic Brain Injury Outcome.

Persistent symptoms are common after a mild traumatic brain injury (mTBI). The Post-Concussion Symptoms (PoCS) Rule is a newly developed clinical decision rule for the prediction of persistent post-concussion symptoms (PPCS) 3 months after an mTBI. The PoCS Rule includes assessment of demographic and clinical characteristics and headache presence in the emergency department (ED), and follow-up assessment of symptoms at 7 days post-injury using two thresholds (lower/higher) for symptom scoring. We examined the PoCS Rule in an independent sample. We analyzed a clinical trial that recruited participants with mTBI from EDs in Greater Vancouver, Canada. The primary analysis used data from 236 participants, who were randomized to a usual care control group, and completed the Rivermead Postconcussion Symptoms Questionnaire at 3 months. The primary outcome was PPCS, as defined by the PoCS authors. We assessed the overall performance of the PoCS rule (area under the receiver operating characteristic curve [AUC]), sensitivity, and specificity. More than 40% of participants (median age 38 years, 59% female) reported PPCS at 3 months. Most participants (88%) were categorized as being at medium risk based on the ED assessment, and a majority were considered as being at high risk according to the final PoCS Rule (81% using a lower threshold and 72% using a higher threshold). The PoCS Rule showed a sensitivity of 93% (95% confidence interval [CI], 88-98; lower threshold) and 85% (95% CI, 78-92; higher threshold), and a specificity of 28% (95% CI, 21-36) and 37% (95% CI, 29-46), respectively. The overall performance was modest (AUC 0.61, 95% CI 0.59, 0.65). In conclusion, the PoCS Rule was sensitive for PPCS, but had a low specificity in our sample. Follow-up assessment of symptoms can improve risk stratification after mTBI.

Autonomic nervous system and endocrine system response to upper or lower cervical spine mobilization in males with persistent post-concussion symptoms: a proof-of-concept trial.

INTRODUCTION: The peripheral stress response, consisting of the autonomic nervous system (ANS) and hypothalamic pituitary adrenal-axis (HPA-axis), functions to maintain homeostasis in response to stressors. Cervical spine manual therapy has been shown to differentially modulate the stress response in healthy populations. No study has investigated whether cervical spine mobilizations can differentially modulate the stress response in individuals with persistent post-concussion symptoms (PPCS), a population characterized by a dysfunctional stress response. METHODS: A randomized, controlled, parallel design trial was performed to investigate whether upper or lower cervical spine mobilization can differentially modulate components of the stress response in individuals with PPCS. The outcomes were salivary cortisol (sCOR) concentration (primary) and the HRV metric, rMSSD, measured with a smartphone application (secondary). Nineteen males diagnosed with PPCS, aged 19-35, were included. Participants were randomly assigned into either intervention group, upper (n = 10) or lower (n = 9) cervical spine mobilization. Each outcome was collected at different time points, pre- and post-intervention. Statistical analyses were performed using the Friedman's Two-Way ANOVA, Mann-Whitney U test, and Wilcoxon Signed Rank Test. RESULTS: There was a statistically significant within-group reduction in sCOR concentration 30 minutes following lower cervical spine mobilizations and statistically significant within-group increase in rMSSD 30 minutes following upper cervical spine mobilizations. CONCLUSION: The results of this trial provide preliminary evidence for cervical spine mobilizations to differentially modulate components of the stress response at specific time points. Understanding the mechanisms of the effect of cervical spine mobilizations on the stress response provides a novel rationale for selecting cervical spine mobilizations to rehabilitate individuals with PPCS.

Evidence for Altered White Matter Organization After Mild Traumatic Brain Injury: A Scoping Review on the Use of Diffusion Magnetic Resonance Imaging and Blood-Based Biomarkers to Investigate Acute Pathology and Relationship to Persistent Post-Concussion Symptoms.

Mild traumatic brain injury (mTBI) is the most common form of traumatic brain injury. Post-concussive symptoms typically resolve after a few weeks although up to 20% of people experience these symptoms for >3 months, termed persistent post-concussive symptoms (PPCS). Subtle white matter (WM) microstructural damage is thought to underlie neurological and cognitive deficits experienced post-mTBI. Evidence suggests that diffusion magnetic resonance imaging (dMRI) and blood-based biomarkers could be used as surrogate markers of WM organization. We conducted a scoping review according to PRISMA-ScR guidelines, aiming to collate evidence for the use of dMRI and/or blood-based biomarkers of WM organization, in mTBI and PPCS, and document relationships between WM biomarkers and symptoms. We focused specifically on biomarkers of axonal or myelin integrity post-mTBI. Biomarkers excluded from this review therefore included the following: astroglial, perivascular, endothelial, and inflammatory markers. A literature search performed across four databases, EMBASE, Scopus, Google Scholar, and ProQuest, identified 100 records: 68 analyzed dMRI, 28 assessed blood-based biomarkers, and 4 used both. Blood biomarker studies commonly assessed axonal cytoskeleton proteins (i.e., tau); dMRI studies assessed measures of WM organization (i.e., fractional anisotropy). Significant biomarker alterations were frequently associated with heightened symptom burden and prolonged recovery time post-injury. These data suggest that dMRI and blood-based biomarkers may be useful proxies of WM organization, although few studies assessed these complementary measures in parallel, and the relationship between modalities remains unclear. Further studies are warranted to assess the benefit of a combined biomarker approach in evaluating alterations to WM organization after mTBI.

[Formula: see text]Persistent post-concussion symptoms in children: pre-injury social difficulties and acute stress reaction as risk factors.

Following mild traumatic brain injury (mTBI) children usually experience one or more somatic, cognitive, and/or emotional-behavioral post-concussion symptoms (PCS). PCS may be transient, however for some children, persistent post-concussion symptoms (PPCS) might linger for months or years. Identifying risk factors for PPCS may allow earlier interventions for patients at greater risk. We examined pre-injury social difficulties and acute stress reaction as risk factors to PPCS in children. Participants were 83 children (aged 8-16) with mTBI. In a prospective follow-up, pre-injury social difficulties, 24-hours post-concussion symptoms, and acute stress reactions were tested as predictors of one-week and four-months PCS reports. Parents' reports, self-reports, and neurocognitive tests were employed. One-week PCS level was associated with acute stress, and not with 24-hours post-concussion symptoms or pre-injury social difficulties. Four-months PCS level was predicted by pre-injury social difficulties and 24-hours post-concussion symptoms, with no contribution of acute stress. Interestingly, less symptoms at 24-hour from injury were associated with a higher level of PCS at four months. Cognitive functioning at four months was predicted by acute stress, with no contribution of 24-hours post-concussion symptoms or pre-injury social difficulties. Cognitive functioning did not differ between children with and without PPCS. In conclusion, non-injury, socio-emotional factors (pre-injury social difficulties, acute stress) should be considered, alongside injury-related factors, in predicting recovery from mTBI. Pre-injury social difficulties and stress reaction to the traumatic event might pose an emotional burden and limit one's social support during recovery, thus require clinical attention in children following mTBI.

From acute stress to persistent post-concussion symptoms: The role of parental accommodation and child's coping strategies.

Background: Acute stress following mild Traumatic Brain Injury (mTBI) is highly prevalent and associated with Persistent Post-Concussion symptoms (PPCS). However, the mechanism mediating this relationship is understudied. Objective: To examine whether parental accommodation (i.e. parents' attempts to adjust the environment to the child's difficulties) and child's coping strategies mediate the association between acute stress and PPCS in children following mTBI. Method: Participants were 58 children aged 8-16 who sustained a mTBI and their parents. Children's acute stress (one-week post-injury) and coping strategies (three weeks post-injury), and parental accommodation (three weeks and four months post-injury) were assessed. Outcome measures included PPCS (four months post-injury) and neuropsychological tests of cognitive functioning (attention and memory). A baseline for PPCS was obtained by a retrospective report of pre-injury symptoms immediately after the injury. Results: Children's acute stress and negative coping strategies (escape-oriented coping strategies) and four-months parental accommodation were significantly related to PPCS. Acute stress predicted PPCS and attention and memory performance. Parental accommodation significantly mediated the association between acute stress and PPCS. Conclusions: Stress plays an important role in children's recovery from mTBI and PPCS. Parental accommodation mediates this relationship, and thus, clinical attention to parental reactions during recovery is needed.

Lack of association between four biomarkers and persistent post-concussion symptoms after a mild traumatic brain injury.

Approximately 15 % of individuals who sustained a mild Traumatic Brain Injury (TBI) develop persistent post-concussion symptoms (PPCS). We hypothesized that blood biomarkers drawn in the Emergency Department (ED) could help predict PPCS. The main objective of this project was to measure the association between four biomarkers and PPCS at 90 days post mild TBI. We conducted a prospective cohort study in seven Canadian EDs. Patients aged ≥ 14 years presenting to the ED within 24 h of a mild TBI who were discharged were eligible. Clinical data and blood samples were collected in the ED, and a standardized questionnaire was administered 90 days later to assess the presence of symptoms. The following biomarkers were analyzed: S100B protein, Neuron Specific Enolase (NSE), cleaved-Tau (c-Tau) and Glial Fibrillary Acidic Protein (GFAP). The primary outcome measure was the presence of PPCS at 90 days after trauma. Relative risks and Areas Under the Curve (AUC) were computed. A total of 595 patients were included, and 13.8 % suffered from PPCS at 90 days. The relative risk of PPCS was 0.9 (95 % CI: 0.5-1.8) for S100B ≥ 20 pg/mL, 1.0 (95 % CI: 0.6-1.5) for NSE ≥ 200 pg/mL, 3.4 (95 % CI: 0.5-23.4) for GFAP ≥ 100 pg/mL, and 1.0 (95 % CI: 0.6-1.8) for C-Tau ≥ 1500 pg/mL. AUC were 0.50, 0.50, 0.51 and 0.54, respectively. Among mild TBI patients, S100B protein, NSE, c-Tau or GFAP do not seem to predict PPCS. Future research testing of other biomarkers is needed to determine their usefulness in predicting PPCS.

Clinical Outcome following Sport-Related Concussion among Children and Adolescents with a History of Prior Concussion: A Systematic Review.

Authoritative sources advise clinicians and parents that a history of prior concussion confers increased risk for worse outcome from a future concussion. However, the strength of the evidence supporting such pronouncements and thus the extent to which clinicians should incorporate this information into their care and management of pediatric concussion is unclear. This systematic review critically analyzed and synthesized the literature on the association between a history of prior concussion and prognosis/clinical outcome following a subsequent sport-related concussion among children and adolescents. The online databases PubMed, MEDLINE®, PsycINFO®, CINAHL, Cochrane Library, EMBASE, SPORTDiscus, Scopus, and Web of Science were searched from inception to May 15, 2021. From 5118 total records screened, 51 studies (46 cohort studies and five case-control studies) met inclusion criteria, reporting concussion recovery or outcome for 26,643 youth. A median of 36% had a prior history of concussion. Across all studies and outcomes, the majority (k = 37, 72.5%) did not find a statistically significant association between lifetime history of concussion and outcome from a subsequent concussion. Important methodological limitations in the literature were identified. Available studies do not provide consistent or compelling evidence that children and adolescents with a history of concussion are at increased risk for worse clinical outcome following a subsequent sport-related concussion-although methodological limitations temper the strength of this conclusion. Clinicians are cautioned against routinely treating children and adolescents with one or more prior injuries differently and more conservatively, because doing so, in some cases, might be counterproductive.

Post-Concussion Symptoms Rule: Derivation and Validation of a Clinical Decision Rule for Early Prediction of Persistent Symptoms after a Mild Traumatic Brain Injury.

Mild traumatic brain injury (mTBI) is a common problem. Depending on diagnostic criteria, 13 to 62% of those patients develop persistent post-concussion symptoms (PPCS). The main objective of this prospective multi-center study is to derive and validate a clinical decision rule (CDR) for the early prediction of PPCS. Patients aged ≥14 years were included if they presented to one of our seven participating emergency departments (EDs) within 24 h of an mTBI. Clinical data were collected in the ED, and symptom evolution was assessed at 7, 30 and 90 days post-injury using the Rivermead Post-Concussion Questionnaire (RPQ). The primary outcome was PPCS at 90 days after mTBI. A predictive model called the Post-Concussion Symptoms Rule (PoCS Rule) was developed using the methodological standards for CDR. Of the 1083 analyzed patients (471 and 612 for the derivation and validation cohorts, respectively), 15.6% had PPCS. The final model included the following factors assessed in the ED: age, sex, history of prior TBI or mental health disorder, headache in ED, cervical sprain and hemorrhage on computed tomography. The 7-day follow-up identified additional risk factors: headaches, sleep disturbance, fatigue, sensitivity to light, and RPQ ≥21. The PoCS Rule had a sensitivity of 91.4% and 89.6%, a specificity of 53.8% and 44.7% and a negative predictive value of 97.2% and 95.8% in the derivation and validation cohorts, respectively. The PoCS Rule will help emergency physicians quickly stratify the risk of PPCS in mTBI patients and better plan post-discharge resources.

Towards the Development of an Integrative, Evidence-Based Suite of Indicators for the Prediction of Outcome Following Mild Traumatic Brain Injury: Results from a Pilot Study.

BACKGROUND: Persisting post-concussion symptoms (PPCS) is a complex, multifaceted condition in which individuals continue to experience the symptoms of mild traumatic brain injury (mTBI; concussion) beyond the timeframe that it typically takes to recover. Currently, there is no way of knowing which individuals may develop this condition. METHOD: Patients presenting to a hospital emergency department (ED) within 48 h of sustaining a mTBI underwent neuropsychological assessment and demographic, injury-related information and blood samples were collected. Concentrations of blood-based biomarkers neuron specific enolase, neurofilament protein-light, and glial fibrillary acidic protein were assessed, and a subset of patients also underwent diffusion tensor-magnetic resonance imaging; both relative to healthy controls. Individuals were classified as having PPCS if they reported a score of 25 or higher on the Rivermead Postconcussion Symptoms Questionnaire at ~28 days post-injury. Univariate exact logistic regression was performed to identify measures that may be predictive of PPCS. Neuroimaging data were examined for differences in fractional anisotropy (FA) and mean diffusivity in regions of interest. RESULTS: Of n = 36 individuals, three (8.33%) were classified as having PPCS. Increased performance on the Repeatable Battery for the Assessment of Neuropsychological Status Update Total Score (OR = 0.81, 95% CI: 0.61-0.95, p = 0.004), Immediate Memory (OR = 0.79, 95% CI: 0.56-0.94, p = 0.001), and Attention (OR = 0.86, 95% CI: 0.71-0.97, p = 0.007) indices, as well as faster completion of the Trails Making Test B (OR = 1.06, 95% CI: 1.00-1.12, p = 0.032) at ED presentation were associated with a statistically significant decreased odds of an individual being classified as having PPCS. There was no significant association between blood-based biomarkers and PPCS in this small sample, although glial fibrillary acidic protein (GFAP) was significantly increased in individuals with mTBI relative to healthy controls. Furthermore, relative to healthy age and sex-matched controls (n = 8), individuals with mTBI (n = 14) had higher levels of FA within the left inferior frontal occipital fasciculus (t (18.06) = -3.01, p = 0.008). CONCLUSION: Performance on neuropsychological measures may be useful for predicting PPCS, but further investigation is required to elucidate the utility of this and other potential predictors.

Psychogenic Gait Disorder Complicating Recovery After Concussion: A Case Series.

BACKGROUND: Gait impairment is common after concussion. "Dizziness" is associated with prolonged recovery after concussion. Most often each of these symptoms is considered to be of vestibular origin. However, whether or not there are psychological etiologies of gait instability that complicate concussion recovery has been less fully explored. METHODS: A chart review was performed of all patients seen between 2017 and 2019 in a weekly pediatric traumatic brain injury clinic. RESULTS: Of eighty-four patients with traumatic brain injury, five were found to have developed a classic psychogenic gait. All were adolescents at the time of diagnosis. Recognition of this complication led to modification/initiation of physical therapy and/or mental health intervention and eventual resolution for all patients. CONCLUSION: Although uncommon, psychogenic gait disorders may complicate concussion recovery in adolescents likely at a higher rate than their occurrence in the general population. This association has not been previously reported. Accurate diagnosis of psychogenic gait likely improves outcomes in this subset of patients with concussion.

Cervicovestibular rehabilitation in adult with mild traumatic brain injury: a randomised controlled trial protocol.

BACKGROUND: Mild traumatic brain injury (mTBI) is an acknowledged public health problem. Up to 25% of adult with mTBI present persistent symptoms. Headache, dizziness, nausea and neck pain are the most commonly reported symptoms and are frequently associated with cervical spine and vestibular impairments. The most recent international consensus statement (2017 Berlin consensus) recommends the addition of an individualized rehabilitation approach for mTBI with persistent symptoms. The addition of an individualized rehabilitation approach including the evaluation and treatment of cervical and vestibular impairments leading to symptoms such as neck pain, headache and dizziness is, however, recommended based only on limited scientific evidence. The benefit of such intervention should therefore be further investigated. OBJECTIVE: To compare the addition of a 6-week individualized cervicovestibular rehabilitation program to a conventional approach of gradual sub-threshold physical activation (SPA) alone in adults with persistent headache, neck pain and/or dizziness-related following a mTBI on the severity of symptoms and on other indicators of clinical recovery. We hypothesize that such a program will improve all outcomes faster than a conventional approach (between-group differences at 6-week and 12-week). METHODS: In this single-blind, parallel-group randomized controlled trial, 46 adults with subacute (3 to12 weeks post-injury) persistent mTBI symptoms will be randomly assigned to: 1) a 6-week SPA program or 2) SPA combined with a cervicovestibular rehabilitation program. The cervicovestibular rehabilitation program will include education, cervical spine manual therapy and exercises, vestibular rehabilitation and home exercises. All participants will take part in 4 evaluation sessions (baseline, week 6, 12 and 26) performed by a blinded evaluator. The primary outcome will be the Post-Concussion Symptoms Scale. The secondary outcomes will be time to clearance to return to function, number of recurrent episodes, Global Rating of Change, Numerical Pain Rating Scale, Neck Disability Index, Headache Disability Inventory and Dizziness Handicap Inventory. A 2-way ANOVA and an intention-to-treat analysis will be used. DISCUSSION: Controlled trials are needed to determine the best rehabilitation approach for mTBI with persistent symptoms such as neck pain, headache and dizziness. This RCT will be crucial to guide future clinical management recommendations. TRIAL REGISTRATION: ClinicalTrials.gov Identifier - NCT03677661, Registered on September, 15th 2018.