bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heart rate variability: exploring age, sex & concussion symptoms in youth athletes
Authors: Paniccia Melissa , Lee Verweel , Taha Tim , Keightley Michelle , Thomas Scott , Reed Nick 
Published: November 2017

Objective(1) Explore the influence of age, sex on heart rate variability (HRV) in youth athletes; (2) Examine the relationship between baseline/pre-injury concussion symptom domains (physical, cognitive, emotional, fatigue) and HRVDesignCross-sectional.SettingPre-injury/baseline data was obtained from youth athletes across various sports in the Greater Toronto Area.ParticipantsYouth athletes between 13–18 years of age (N=294), in which females and males were equally represented across age groups. Inclusion criteria: between 13–18 years old, English speaking. Exclusion criteria: developmental and neurological diagnoses.InterventionIndependent variables of interest included demographic factors such as age and sex as well as concussion symptoms. Concussion symptoms were measured using the Post Concussion Symptom Inventory and were stratified by physical, cognitive, fatigue and emotional domains.Outcome measuresHeart rate variability, collected over 24 hours was the main outcome of interest and included time (e.g. SDNN, RMSSD) and frequency domain measures (e.g. HF, Total Power). Variables were logarithmically transformed to increase robustness of linear regression models.Main resultsStatistical threshold set at p ≤ 0.05. Significant age effects revealed that older participants displayed higher HRV compared to younger athletes. Significant interaction effect between concussion symptoms and sex on HRV. Cognitive and fatigue symptoms in healthy youth athletes had significant effect on HRV.ConclusionsThis study highlights the potential value of a novel neurophysiological indicator used in conjunction with the self-report of symptoms for clinical management. Prospective longitudinal research is needed to further explore the multi-faceted contextual influences of a youth athlete’s environment.Competing interestsNone.
Evaluation of the HS-1000 acoustic neuromonitoring device in the diagnosis and assessment of sports-induced concussion
Authors: Sills Allen , Lee Timothy , Kwiatkowski Tricia , Swanson Thomas , Weinberg Guy 
Published: November 2017

ObjectiveTo evaluate the correlation between data collected from the HS-1000 multi-modality brain monitoring device and standard neurological, psychomotor, and neuropsychological diagnostics in the assessment of acute sports-induced concussion.DesignProspective, open-label, non-randomised study.SettingCollegiate athletes were recruited at the Vanderbilt Sports Concussion Centre, Nashville, TN.ParticipantsSixty-four subjects across concussed (n1=14) and healthy control (n2=50) arms were consented.Interventions and assessment of risk factorsEligible subjects suffering recent concussion and age/gender-matched healthy controls were enrolled into the study. Participants in both groups were monitored for at least 15min per recording with the HS-1000. Concussed subjects were recorded 4 times relative to time of concussion injury: acute/baseline, 48 hr, 1 wk, 1 mo. Healthy control subjects were recorded at 2 time points: baseline, 2 wk.Outcome measuresStandard clinical diagnostics and demographic information were collected from all study participants. As per current clinical standards and their assigned group, concussed subjects received Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Modified Balance Assessment Scale (mBESS), and total clinical symptom index scores. MathWorks MATLAB™ (Matrix Laboratory) engineering software was used to interpret signals and calculate sensitivity-specificity as a function of predictive accuracy with clinically confirmed concussion status.Main resultsPost-processing of HS-1000 signals identified concussed athletes with a sensitivity-specificity of 86.1% and 91%, respectively.ConclusionsThe HS-1000 demonstrated strong predictive accuracy compared with clinical diagnosis. Improved statistical power through greater sampling sizes and the development of a real-time diagnostic algorithm suggests this technology holds promise in the assessment and diagnosis of sports-induced concussion.Competing interestsNone.
Transcranial doppler ultrasound measures of neurovascular coupling are maintained following acute sport-related concussion
Authors: Smirl Jonathan D , Wright Alexander D , Bouliane Kevin , Bryk Kelsey , Donkelaar Paul van 
Published: November 2017

ObjectiveTo determinethe extentto which an acute sport-related concussion disrupts elevations in cerebral blood velocity (CBV) in the posterior cerebral artery (PCA) during visual tasks.DesignProspective Cohort.SettingLaboratory.Participants136 male contact-sport athletes (19.1±1.4 years) recruited, subset of 14 participants (19±1.4 years) sustained concussions.InterventionTranscranial Doppler ultrasound was used to index CBV in the PCA during a series of visual tasks. Participants closed their eyes (20 seconds), and when prompted, opened their eyes and completed a visual task (40 seconds). Testing was completed prior to the start of their athletic season (T0), and again (if concussed) at 72-hours (T1), 2-weeks (T2), and 1-month (T3) post-injury. The raw traces from each trial were averaged to enhance the signal-to-noise ratio of the outcome measurements. Independent variable tested was time (4 points).Outcome measuresEyes-closed CBV (cm/s), peak elevation in CBV (cm/s), relative change in CBV (%) and total activation during the first 30 seconds of the task (indexed via area under the curve-AUC)Main resultsRM-ANOVA indicated there were no time effects forany of the outcome metrics: Eyes-closed CBV (p=0.473), peak CBV (p=0.541),% CBV elevation (p=0.603) and AUC (p=0.972).ConclusionsThese negative findings are important, as they indicate the PCA is able to maintain nutrient delivery required for visual challenges. Thus, neurovascular coupling is maintained despite the reported impairments in indices of cerebral autoregulation in the same population.Competing interestsNone.
Utilisation of brain network activation in the concussed athlete a case series
Authors: Danan Ilan J , Williams Vernon B , Mandelbaum Bert R 
Published: November 2017

ObjectiveWhile the approach to concussion and post-concussion syndrome management remains largely clinical, significant advancements have been made in identifying potential biomarkers to aid in the diagnosis and management of head injures. One such potential biomarker is Brain Network Activation (BNA) analysis. BNA is a multi-channel, EEG-ERP based platform that involves algorithmic analysis to provide a network map of cortical activity and quantitative data during specific tasks.DesignCase Series.SettingOutpatient, clinic-based.ParticipantsThree (3) athletes.Outcome measuresAnalysis of the subject’s BNA performance yieldsa BNA score,which reflects the degree of similarity between the performance of the subject and the normative data. BNA scores are further placed into one of three subcategories: Working Memory and Attention (Target Stimuli), Automatic Attention Orienting (Novel Stimuli), and Sensory (Frequent Stimuli). Each subject underwent a BNA analysis while symptomatic, followed by repeat analyses once subjects were identified as clinically asymptomatic.Main resultsIn each of the three studies, there were improvements in BNA scores identified in one, or several, subcategories. More importantly, improvements in BNA scores directly correlated with clinical improvement in the post-concussive setting.ConclusionsApproach to concussion management, in both the short-term and long-term setting, remains largely clinical. Current research seeks a more objective means of assessing not only potential structural abnormalities following a concussion, but also an improved means of assessing a patient’s neurocognitive status. BNA has proven to be an effective, supportive tool in allowing clinicians and patients to objectify one’s progress following a concussive injury.Competing interestsNone.
Clinical characteristics, referral patterns and time to recovery in youth and adults following a sport-related concussion (src)
Authors: MacGregor Katie , Atkins Christine , Blake Tracy , Ziel Micah , Schneider Kathryn 
Published: November 2017

ObjectiveTo describe the clinical characteristics, referral patterns and time to recovery in an acute sport-related concussion (SRC) clinic population.DesignProspective Case SeriesSettingAcute Sport Concussion Clinic (ASCC)ParticipantsPatients aged 13-60 years seen within 4 weeks of SRC at the ASCC from September 2015–April 2016.Outcome measuresFrequency, proportions, medians and interquartile ranges (IQR) were used to describe sex, age group, time from injury to assessment, referral sources, time to recovery (days), referrals to additional services, and attrition.ResultsASCC assessments were requested by 111 patients a median of 9 days (IQR:4-17) post-concussion [33% female; 60 children [median age 15 years (IQR:14-16)], 51 adults [median age 31 years (IQR:21-42)]; attrition rate=10%]. Referral sources included: self-referral [n=94 (85%)], emergency department [n=9 (8%)], primary care physician [n=7 (5%)], and athletic therapist (n=1). Initial assessment occurred a median of 7 days (IQR:2-9) following the evaluation request. Patients underwent a standardised assessment including symptom scores, neurological, cervical spine and vestibulo-ocular screening a median of 17 days (IQR:9-25) post-concussion. There were 94 (85%) patients with clinical findings of cervical spine and/or vestibulo-ocular dysfunction. Treatment was received by 71/94 (76%) of patients with observed dysfunction. Medical clearance to return to play occurred a median of 30 days (IQR:21-107) post-concussion (n=51) .ConclusionsA novel direct-access clinic specific to SRC assists in early triage, leading to expedited assessment, management and treatment in the early post-concussion period. Focused assessment assists in management and recovery with accelerated referral to appropriate services.Competing interestsNone.
Concussion is associated with altered preparatory postural adjustments during gait initiation
Authors: Doherty C , Ryan John , Komaba Yusuke , Inomata Akihiro , Zhao Liang , Caulfield Brian 
Published: November 2017

ObjectiveTo quantify the preparatory postural adjustments (PPAs) during gait initiation (GI) in a group with concussion compared with a ‘healthy’ control group.DesignCase-control studySettingUniversity Biomechanics Laboratory.Outcome measuresCentre of pressure (COP) trajectory computed from a force plate and centre of mass (COM) trajectory as computed from an inertial measurement unit placed on the sacrum.ResultsConcussed patients exhibited decreased COP excursion in the posterior direction on their dominant foot, both when it was the stepping limb (9.71mm [95% CI: 8 to 11mm] vs 15mm [95%CI: 12 to 17mm]) and when it was the support limb (10mm [95% CI: 8 to 12mm] vs 18mm [95%CI: 14 to 21mm]). This was reflected in the trajectory of the COM, wherein concussion patients exhibited lower posterior displacement (19mm [95%CI: 19.4mm to 19.7mm]) compared with controls (23mm [95%CI: 23 to 24]).Conclusions: Individuals with concussion display deficits during a GI task comparable to those which have previously been established in populations with supraspinal impairments in motor control.Competing interestsNone.
Driving after concussion: is it safe to drive after symptoms resolve?
Authors: Schmidt Julianne D , Devos Hannes , Hoffman Nicole L , Ranchet Maud , Akinwuntan Abiodun E , Miller L Stephen 
Published: November 2017

ObjectiveTo compare simulated driving performance between concussed and control participants.DesignCross-sectional.SettingLaboratory.SubjectsFourteen concussed participants and 14 non-concussed age and driving experience matched controls with no neurological disorders, medications causing drowsiness, or heavy drugs/alcohol use (Age: 20.3years, 95%CI:19.9,20.7).InterventionParticipants completed a 7.6 minute, 20.5km driving simulation task containing curves, crosswalks, accidents, rural/urban areas, pedestrians, overtaking, and evasion. Concussed participants completed driving simulation within 48 hours of becoming asymptomatic (15.9 days post-concussion, 95%CI: 10.7,21.0) and were deemed clinically recovered by a medical professional using a multifaceted concussion evaluation.Outcome measuresWe compared total number of accidents, tickets, and lane excursions between groups.We also comparedaverage velocity (km/hr), standard deviation of velocity, lateral lane position (m), and lateral lane position standard deviation throughout simulation subsections. One-way ANOVAs were used (α=0.05).ResultsConcussed participants committed more frequent lane excursions compared to controls (concussed: 10.9, 95%CI:8.3,13.5; controls: 7.4, 95%CI:6.0,8.8; p=0.02). Concussed participants exhibited greater lateral lane position standard deviation compared to controls during the first (concussed: 1.1m, 95%CI: 0.8,1.5; controls: 0.7m, 95%CI:0.6, 0.9; p=0.02) and final curve (concussed: 1.2m, 95%CI:1.1,1.3; controls: 1.0m, 95%CI:0.9,1.1; p=0.04).ConclusionsDespite being considered clinically recovered, concussed participants were less able to centre the vehicle in the lane and entered the shoulder more frequently, especially when navigating curves. A concussion may impair visual, motor, and/or cognitive skills necessary to safely drive. Further research is needed to determine when it is safe to return to driving following concussion.Competing interestsNone.
Near point convergence and other measures of vestibulo-ocular dysfunction are associated with protracted neurological recovery after sports concussion
Authors: Russman Andrew , Linder Susan , Grey Bob , Figler Rick , Cruickshank Jason , Lally Maureen , Alberts Jay , Day Tanujit 
Published: November 2017

ObjectiveTo characterise specific measures of neurologic dysfunction and recovery associated with concussion in student-athletes using the clinical examination and Cleveland Clinic Concussion application (C3 app).DesignRetrospective observational studySettingTertiary sports concussion clinicParticipants181 student-athletes aged 14-20 diagnosed with concussion by a Cleveland Clinic physician were included.InterventionsC3 data were collected pre-season, and at least once post-injury, along with a physician clinical examination. Individuals were stratified into two groups based on recovery time: typical <21 days (n=97) or protracted 21+ days (n=84).Outcome measuresNear point convergence (NPC) and the following modules of the C3 app were administered: 1) Graded symptom checklist (GSC); 2) Standardised Assessment of Concussion (SAC); 3) Trail Making Test (TMT); 4) Simple and Choice Reaction Time; 5) Processing Speed Test (PST); 6) Biomechanical quantification of balance during the BESS.Main resultsAt baseline, both groups performed similarly on all C3 modules. Significant differences in NPC were seen among the typical versus protracted group (mean 7.62 cm versus 13.57 cm, p=0.0002). Also, significantly worse performance among the protracted group was seen in GSC (p=0.0001), and measures affected by vestibulo-ocular dysfunction including biomechanical quantification of BESS (p<0.05), simple and choice reaction time (p<0.001), and TMT-B (p=0.01). No difference between groups was noted in BESS errors, SAC, or PST.ConclusionsAbnormal NPC or convergence insufficiency is associated with protracted recovery and should be included in the assessment of student-athletes at baseline and post-injury. Identification of vestibulo-ocular dysfunction helps guide post-concussion assessment, treatment, and return-to-play decision-making.Competing interestsBob Gray, Rick Figler, Jason Cruickshank, Maureen Lally, Tanujit Day: None. Susan Linder and Jay Alberts have authored intellectual property associated with the mobile application presented in this study.
Postural control deficits in collegiate athletes following mild concussions within the first 48 hours
Authors: Soria Selena Mae , Rauh Mitchell J , Goble Daniel J , Baweja Harsimran S 
Published: November 2017

ObjectiveThe purpose of this study was to determine the extent of postural control deficits accompanying concussions in Division I collegiate athletes within 48 hours of injury.DesignCross-sectional study.SettingUniversity Athletic Training Department & Biomechanics Laboratory.ParticipantsPreseason baseline balance testing of 519 healthy Division I college athletes was performed with the BTrackS Balance Test (San Diego, CA). Of the baselined athletes, 26 (18–23 years; 14 females) experienced a concussion during the ensuing sport season. Post-injury balance testing was performed on these concussed athletes within 48 hours of injury. Additionally, 20 healthy young adults (19–25 years; 10 females) were baselined on 2 sessions 7 days apart.Outcome measuresAll testing consisted of three 20s trials of quiet unperturbed standing with eyes closed; feet shoulder width apart and hands on the hips. We calculated total centre of pressure (COP), COP antero-posterior (AP), and COP medio-lateral (ML) sway displacements. A principle component analysis was used to calculate the 99% confidence intervals (CI) of the COP area.Main resultsThere were no preseason baseline differences in any of the balance measures between athletes and controls. However, postural displacement in all directions (AP, ML, and Total) increased significantly in athletes post-injury. Furthermore, ~80% of the increase in COP excursions was accounted for by a ~7 fold increase in the COP area post-injury.ConclusionsOur findings are indicative of a decrease in postural control and multisensory integration post-concussion. Future studies should investigate the long-term effects and recovery from concussions in athletes.Competing interestsOne author (Goble) holds an equity stake in the parent company for the BTrackS Balance Plate. This conflict of interest was strictly managed by San Diego State University through a mitigation plan that limits his involvement in all primary aspects of data collection and analysis. All other authors have no conflict of interest to declare.
Mild traumatic brain injury is associated with increased levels of axonal injury biomarkers in blood
Authors: Shahim Pashtun , Blennow Kaj , Zetterberg Henrik , Tegner Yelverton 
Published: November 2017

ObjectiveTo investigate whether sports-related concussion is associated with elevated blood biomarkers reflecting axonal injury (total-tau [T-tau], [tau-A] and [tau-C]) and astroglial injury (S100B), as well as neurons-specific enolase (NSE).Design and settingA multicenter prospective cohort study involving all 12 teams of the top professional ice hockey league in Sweden.ParticipantsA total of 288 players consented to participate in the study. Thirty-five players sustained concussions, of whom 28 underwent repeated blood samplings at 1, 12, 36, and 144 hours after the trauma, or when the player returned to play (7->90 days).Outcome measuresConcentrations of T-tau was, tau-A, tau-C, S100B and NSE in blood.ResultsPlayers with sports-related concussion had increased levels of the axonal injury biomarker T-tau compared to preseason values. The highest biomarker concentrations of T-tau were measured immediately after a concussion and decreased during rehabilitation. There was no significant increase in the levels of tau-A in post-concussion samples compared with preseason values. However, serum levels of tau-C were significantly higher in post-concussion samples compared with preseason. The levels of the astroglial injury biomarker S100B were also increased in players with sports-related concussion compared to preseason values. No significant changes were measured in the levels of NSE.ConclusionsSports-related concussion in professional ice hockey players is associated with acute axonal and injury. Plasma T-tau may be used both in the diagnosis and clinical decision-making when an athlete is declared fit to return to play.Competing interestsNone.
Concussion education: a randomised trial with undergraduate students
Authors: Kobitowich Tara , Mrazik Martin 
Published: November 2017

ObjectiveTo evaluate optimal methods for educating individuals about concussions.DesignProspective randomised controlled trial.SettingUniversity setting.Participants162 undergraduate students.InterventionStudents from a university participant pool were randomly assigned to one of three conditions: 1) control group (CN); 2) internet group (IG); 3) presentation group (PG). All subjects completed the knowledge concussion questionnaire (18 questions) in the concussion knowledge section of the questionnaire published by Rosenbaum & Arnett (2014). Subjects completed a pretest and a posttest. The IG was provided with 3 websites and given 30 minutes to review this material. The PG group was involved in a 45 minute interactive lecture from a neuropsychologist.Main outcome measureConcussion knowledge.Main resultsA repeated measures ANOVA suggested a significant interaction between group and time F (2, 159)=30.2, p<0.001. The PG demonstrated significantly higher scores at posttest compared with both the IG and CN groups [(F (2, 159)=12.6, p<0.001 although all groups presented with improved scores at the posttest interval compared with the pretest. Post-hoc pairwise comparison at posttest interval between CN and IG groups did not reach statistical significance (p=0.50). Specific items suggested inaccurate information about concussions may be common in the undergraduate population.ConclusionsThere are many methods used to educate athletes about concussions. As expected, an interactive presentation about concussions was more effective at improving concussion knowledge than reviewing information from the internet. Results also suggested the importance of clarifying existing myths about concussionsConflictsThere were no conflicts to declare.Competing interestsNone.
Knowledge, attitudes and intended behaviours in relation to concussion in professional rugby union players
Authors: Stokes Keith , Kemp Simon , Michell Miss Rachel , Standage Martyn , McKay Carly 
Published: November 2017

ObjectiveTo investigate knowledge, attitudes and intended behaviours in relation to concussion in professional Rugby Union players.DesignCross-sectional study.SettingEnglish Premiership and Championship (the highest levels of domestic competition in England).Participants1236 professional male players enrolled on a compulsory online concussion education module were invited to respond to an online survey in October 2014. 383 players completed the survey (age 17–40 years; 0.5–19 years of professional rugby).Outcome measuresNumber of career self-reported concussions; pre-module concussion identification and management knowledge score (5 multiple-choice questions); attitudes towards concussion (14 7-point Likert-scale questions; higher scores represent more favourable attitudes); intended behaviours regarding concussion reporting (3 7-point Likert-scale questions; lower scores represent more favourable intended behaviours).Main results271 players (71%) recalled at least one concussion during their playing career; 249 (65%) recalled 1–5, 17 (4%) recalled 6-10 and 3 (1%) recalled >10 concussions. Knowledge scores (n=292) ranged from 0 to 5 correct answers out of 5; mean(SD) 3.4 (1.8). Attitudes scores (n=383) ranged from 42 to 98 out of a possible 98; mean(SD), 75.7 (11.9). Intended behaviour scores (n=383) ranged from 6 to 21 out of a possible 21; mean(SD), 10.2 (3.3). Spearmans Rank indicated that knowledge scores and concussion history were not associated with attitudes or intended behaviours; however, more favourable attitude scores were associated with more favourable intended behaviour scores (rs=−0.34, p<0.001).ConclusionsConcussion education interventions should focus on positively influencing player attitudes towards concussion as this has the greatest potential to improve player behaviour.Competing interestsDr. Keith Stokes – Receives research funding from the Rugby Football UnionDr. Simon Kemp – Employed by the Rugby Football UnionMiss Rachel Michell – Employed by Rugby Players AssociationisDr. Martyn Standage, Dr. Carly McKay - None.