Symptoms Associated With Exercise Intolerance and Resting Heart Rate Following Mild Traumatic Brain Injury.

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

A retrospective analysis of concussion and post-concussional syndrome diagnoses in Western Australian emergency departments.

OBJECTIVE(S): To determine the rate of concussion diagnoses per capita recorded in hospital emergency departments in Western Australia (WA) from 2002-2018 for ICD-10-AM concussion diagnoses S06.00-S06.05, and post-concussional syndrome (PCS) (F07.2). DESIGN, SETTING AND ANALYSIS: Retrospective analysis of hospital Emergency Department (ED) presentations and hospital admissions from all WA hospitals for all patients with an ICD-10-AM diagnosis code for concussion and post-concussional syndrome (PCS) over the period 2002-2018. Data pertaining to concussion and PCS presentations were extracted from the WA Department of Health Emergency Department Data Collection (EDDC). Total case numbers were aggregated by year (2002-2018) and regions of WA. MAIN OUTCOME MEASURES: The rates of diagnoses were calculated based on the population in the specific region and expressed as incidence rate per 100,000 person-years. The overall trends of diagnoses across the regions were analysed using negative binomial regression models and expressed as incidence rate ratio (IRR) with the corresponding 95 % CI, whilst adjusting for region. Tests for linearity were also performed. RESULTS: The rate of concussion diagnosis had significantly increased linearly over the years (p for trend: p < 0.001) whilst the rate of PCS diagnosis had significantly declined linearly over the same period (p for trend: p < 0.001). CONCLUSION: There was significant increase in all-cause ICD-10-AM concussion diagnoses in WA emergency departments. To further clarify the incidence and prevalence of all-cause concussion in Australia, investigation must focus on truly reflective S06.0 codes and include data linkage to primary care data. Conversely PCS ED presentations reduced; whether this relates to a change in where presentations occur for management of such a diagnosis, improved early intervention or an alternative explanation warrants further investigation.

Neuroimaging to enhance understanding of cardiovascular autonomic changes associated with mild traumatic brain injury: a scoping review.

BACKGROUND: Cardiovascular changes, such as altered heart rate and blood pressure, have been identified in some individuals following mild traumatic brain injury (mTBI) and may be related to disturbances of the autonomic nervous system and cerebral blood flow. METHODS: We conducted a scoping review according to PRISMA-ScR guidelines across six databases (Medline, CINAHL, Web of Science, PsychInfo, SportDiscus and Google Scholar) to explore literature examining both cardiovascular parameters and neuroimaging modalities following mTBI, with the aim of better understanding the pathophysiological basis of cardiovascular autonomic changes associated with mTBI. RESULTS: Twenty-nine studies were included and two main research approaches emerged from data synthesis. Firstly, more than half the studies used transcranial Doppler ultrasound and found evidence of cerebral blood flow impairments that persisted beyond symptom resolution. Secondly, studies utilizing advanced MRI identified microstructural injury within brain regions responsible for cardiac autonomic function, providing preliminary evidence that cardiovascular autonomic changes are a consequence of injury to these areas. CONCLUSION: Neuroimaging modalities hold considerable potential to aid understanding of the complex relationship between cardiovascular changes and brain pathophysiology associated with mTBI. However, it is difficult to draw definitive conclusions from the available data due to variability in study methodology and terminology.

Predicting outcome following mild traumatic brain injury: protocol for the longitudinal, prospective, observational Concussion Recovery (CREST) cohort study.

INTRODUCTION: Mild traumatic brain injury (mTBI) is a complex injury with heterogeneous physical, cognitive, emotional and functional outcomes. Many who sustain mTBI recover within 2 weeks of injury; however, approximately 10%-20% of individuals experience mTBI symptoms beyond this 'typical' recovery timeframe, known as persistent post-concussion symptoms (PPCS). Despite increasing interest in PPCS, uncertainty remains regarding its prevalence in community-based populations and the extent to which poor recovery may be identified using early predictive markers. OBJECTIVE: (1) Establish a research dataset of people who have experienced mTBI and document their recovery trajectories; (2) Evaluate a broad range of novel and established prognostic factors for inclusion in a predictive model for PPCS. METHODS AND ANALYSIS: The Concussion Recovery Study (CREST) is a prospective, longitudinal observational cohort study conducted in Perth, Western Australia. CREST is recruiting adults aged 18-65 from medical and community-based settings with acute diagnosis of mTBI. CREST will create a state-wide research dataset of mTBI cases, with data being collected in two phases. Phase I collates data on demographics, medical background, lifestyle habits, nature of injury and acute mTBI symptomatology. In Phase II, participants undergo neuropsychological evaluation, exercise tolerance and vestibular/ocular motor screening, MRI, quantitative electroencephalography and blood-based biomarker assessment. Follow-up is conducted via telephone interview at 1, 3, 6 and 12 months after injury. Primary outcome measures are presence of PPCS and quality of life, as measured by the Post-Concussion Symptom Scale and the Quality of Life after Brain Injury questionnaires, respectively. Multivariate modelling will examine the prognostic value of promising factors. ETHICS AND DISSEMINATION: Human Research Ethics Committees of Royal Perth Hospital (#RGS0000003024), Curtin University (HRE2019-0209), Ramsay Health Care (#2009) and St John of God Health Care (#1628) have approved this study protocol. Findings will be published in peer-reviewed journals and presented at scientific conferences. TRIAL REGISTRATION NUMBER: ACTRN12619001226190.

A cross-sectional study reporting concussion exposure, assessment and management in Western Australian general practice.

BACKGROUND: General Practitioners (GPs) may be called upon to assess patients who have sustained a concussion despite limited information being available at this assessment. Information relating to how concussion is actually being assessed and managed in General Practice is scarce. This study aimed to identify characteristics of current Western Australian (WA) GP exposure to patients with concussion, factors associated with GPs' knowledge of concussion, confidence of GPs in diagnosing and managing patients with concussion, typical referral practices and familiarity of GPs with guidelines. METHODS: In this cross-sectional study, GPs in WA were recruited via the RACGP WA newsletter and shareGP and the consented GPs completed an electronic survey. Associations were performed using Chi-squared tests or Fisher's Exact test. RESULTS: Sixty-six GPs in WA responded to the survey (response rate = 1.7%). Demographics, usual practice, knowledge, confidence, identification of prolonged recovery as well as guideline and resource awareness of GPs who practised in regional and metropolitan areas were comparable (p > 0.05). Characteristics of GPs were similar between those who identified all symptoms of concussion and distractors correctly and those who did not (p > 0.05). However, 84% of the respondents who had never heard of concussion guidelines were less likely to answer all symptoms and distractors correctly (p = 0.039). Whilst 78% of the GPs who were confident in their diagnoses had heard of guidelines (p = 0.029), confidence in managing concussion was not significantly associated with GPs exposure to guidelines. It should be noted that none of the respondents correctly identified signs of concussion and excluded the distractors. CONCLUSIONS: Knowledge surrounding concussion guidelines, diagnosis and management varied across GPs in WA. Promotion of available concussion guidelines may assist GPs who lack confidence in making a diagnosis. The lack of association between GPs exposure to guidelines and confidence managing concussion highlights that concussion management may be an area where GPs could benefit from additional education and support.