bluuebunny/crossref_metadata_2025_split huggingface dataset:
Head impact exposure and time to recovery in youth american football players diagnosed with a concussion
Authors: Valentine Verle D , Dorman Jason C , Munce Thayne A 
Published: November 2017

ObjectiveTo compare head impact exposure (HIE) sustained by youth American football players on days of concussion with prior sessions, and to evaluate concussion resolution with objective assessments.DesignProspective,observational study.SettingYouth American football.ParticipantsYouth American football players (11-14 yr, n=57) who had head impact sensors embedded in their helmets; six were diagnosed with a concussion.InterventionsOver four consecutive seasons, baseline and post-injury concussion assessments were performed and HIE was monitored (Head Impact Telemetry system) for all practice/game sessions.Outcome measuresBaseline/Post-concussion assessments – symptoms, balance, reaction time, neurocognitive function (ImPACT), and oculomotor performance (King-Devick). HIE – location, frequency, and magnitude (linear acceleration [LA] and rotational acceleration [RA]).Main resultsFor concussive impacts, the average peak LA was 85.9g(39.7-156.8g) and average peak RA was 6918rad·sec-2(4508-8433rad·sec-2). On average, players sustained 21.3 impacts/session on days of concussion vs. 10.2 in previous sessions. Median LA and RA did not differ on days of concussion when compared to prior sessions (21.9 vs. 20.7g; 1480 vs. 1485 rad·sec-2). Average duration for a concussed player to have his assessment values return to baseline and be cleared for play was 32 days (17-53).ConclusionsConsiderable variation in magnitude existed between impacts that lead to concussion in this population. Players sustained more head impacts in sessions with a concussion compared to prior sessions. Frequency and magnitude of head impacts on the day of concussion did not correlate with time to recovery. Continued observation of a larger cohort is warranted.Competing interestsNone.
Longitudinal changes in health-related quality of life during concussion recovery among youth athletes
Authors: Russell Kelly , Selci Erin , Fineblit Samuel , Ellis Michael 
Published: November 2017

ObjectiveDetermine longitudinal changes in health-related quality of life (HRQoL) in youth during recovery from a sport-related concussion.DesignProspective case-series.Participants68 youth (13–18 years; 62% male) with an acute sport-related concussion were enrolled with 5 lost to follow-up.Intervention (or assessment of risk factors)Subsequently developing Post-Concussion Syndrome (PCS: symptomatic after 30 days), initial symptom severity (Post Concussion Symptom Scale), concussion history, sex, age, and academic accommodations during recovery.Outcome measuresPedsQL Cognitive Functioning Scale and PedsQL 4.0 measured physical, social, and emotional domains of HRQoL. They were administered before each appointment until medical clearance. Multivariable mixed modelling accounted for repeated measures within an athlete and expressed as point increase per week.Main resultsInitial mean HRQoL was highest for social (non-PCS: 92.7 out of 100; PCS: 86.3), followed by emotional (non-PCS: 86.45; PCS: 69.7), physical (non-PCS: 80.95; PCS: 49.2), and cognitive domains (non-PCS: 69.1; PCS: 50.3). There was effect modification by developing PCS. Changes in HRQoL subscores were: cognitive functioning non-PCS (+9.8 points [95% CI: 6.9, 12.7]) and PCS (+4.2 points [95% CI: 2.8, 5.6]); social HRQoL non-PCS (+2.3 points [1.0, 4.0]) and PCS (+0.5 points [0.1, 1.0); emotional HRQoL non-PCS (+5.0 points [95% CI: 2.9, 7.0]) and PCS points (+2.2 [1.6, 2.9]); and physical non-PCS (+6.3 points [95% CI: [3.5, 9.2]) and PCS (+3.3 points (95% CI: 2.5, 4.2).ConclusionsHRQoL significantly improved longitudinally with greater improvement among non-PCS athletes. HRQoL impairment was most apparent in the cognitive and physical domains.Competing interestsNone.
Physical activity and concussion risk in male youth ice hockey players
Authors: A Blake Tracy , H Meeuwisse Willem , K Doyle-Baker Patricia , L Brooks Brian , Palacios-Derflingher Luz , A Emery Carolyn 
Published: November 2017

ObjectiveTo evaluate the association between self-reported physical activity (PA) and concussion incidence in male youth ice hockey players.Designpooled data from three prospective cohort studies.SettingCommunity ice hockey rinks and sport medicine clinics.ParticipantsPeeWee (ages 11–12), Bantam (ages 13–14), and Midget (ages 15–17) male youth ice hockey players (n=1208).Assesment of risk factorsParticipants reported six-week physical education and extra-curricular sport participation history upon study entry. Concussion incidence rate ratios [IRRs (95% CI)] associated with 1). total six-week PA volume, and 2). meeting the Canadian PA recommendations of one hour of daily PA (≥42 hours/six weeks) were calculated using multivariable Poisson regression (covariates: age, competition level, concussion history). Models were adjusted for hockey exposure, and cluster by team, study year and city (α<0.05).Outcome measureMedically-diagnosed concussions during the study period.Main resultsTotal PA volume did not affect concussion incidence in male youth ice hockey players [IRR: 0.996 (95% CI: 0.990–1.003]. Concussion incidence was higher in male ice hockey players who did not meet the PA recommendations versus those who met the PA recommendations amongst PeeWee [IRR: 2.94 (95% CI: 1.29–6.66)] and Bantam [IRR: 2.18 (95% CI: 1.12–3.94)] participants, but not amongst Midget participants [IRR: 1.37 (95% CI: 0.72–2.59)]. There was no evidence of confounding or modification by competition level or concussion history.ConclusionsWhile total PA volume was not associated with concussion risk, PeeWee and Bantam male youth ice hockey players whose six-week PA history was below the PA recommendations were at greater risk of concussion. This research will inform future studies examining the mechanism of this association.Competing interestsNone.
Presenting symptoms and recovery time among youth athletes with and without a history of concussion
Authors: Russell Kelly , Krisko Cameron , Ellis Michael 
Published: November 2017

ObjectiveDetermine if youth athletes with a history of concussion had more symptoms, higher symptom score, longer recovery, or were more likely to be diagnosed with Post-Concussion Syndrome (PCS) than those with no history of concussion.DesignRetrospective chart review.SettingPaediatric, multi-disciplinary concussion.Participants306 youth (mean 14.0 years, SD 2.3; 65.5% male) with an acute sport-related concussion.Intervention (or assessment of risk factors)Self-reported concussion history.Outcome measuresRecovery days were days between concussion and medical clearance by the neurosurgeon. Medical clearance occurred after tolerating full-time school, completing return-to-play protocol, and absence of vestibulo-ocular dysfunction. Initial symptoms were reported on the Post Concussion Symptom Severity score (PCSS); symptom severity was the total PCSS score. The neurosurgeon diagnosed Post-Concussion Syndrome (PCS) using ICD-10 criteria of symptoms for at least 30 days.Main resultsMedian number of initial symptoms was 5.5 (IQR: 1–10) for youth with no concussion history and 7.0 (IQR: 2–14) with a concussion history (p=0.04). Initial median PCSS score was 9 (IQR: 1–22) for youth with no concussion history and 13 (IQR: 3–34) with a concussion history (p=0.03). Median recovery days was 22 (IQR: 15–43) for those with no concussion history compared to 23 (IQR: 16–39) with a concussion history (p=0.41). There was no significant difference in subsequently being diagnosed with PCS (no concussion history: 40.1%, ?concussion history: 41.7%, p=0.73).ConclusionsDespite a significantly higher initial symptom burden among those with a concussion history, there was no increased risk of protracted recovery or subsequent diagnosis of PCS.Competing interestsNone.
Prospective observational cohort of paediatricpediatric sport-related concussion
Authors: Dilworth Neil , Karam Siobhan , Eardley Ryan , Kraft Sari , Shukla Hemen , Leung Mark , Smith Ira 
Published: November 2017

ObjectiveTo determine the symptom duration, and time to return to school and sport after sport-related concussion in paediatric population aged 12–18 years. Symptom duration was hypothesised to be >7–10 days.DesignProspective observational cohort study.SettingLarge urban community primary care sports medicine clinic.Paticipants30 participants age 12–18 years (Male: n=27;Female: n=3) presenting to clinic ≤14 days with sport-related concussion. 100% completed study. Exclusion criteria: age <12 and >18 years, presentation ≥15 days, non-sport related concussion.Independent variable(s)/modifiersSport, SCAT3 score, past medical and concussion history, objective assessment variables (oculomotor, near-point convergence, vestibular, cognitive, cervical dysfunction).Outcome measuresSymptom duration, return to sport, return to school (days)Main resultsMost concussions occurred playing ice-hockey (53%), followed by Canadian football and basketball. Mean intake SCAT3 symptom number was 10 and symptom score was 22. Patient characteristics included prior concussion (50%), prior neurological conditions (40%), and pre-existing psychological diagnosis (20%). The mean initial exam findings included near point convergence=6.5 cm and Balance Error Scoring System=26.1/30. Vestibular dysfunction (46.7%), cervical pain (53.3%), and abnormal coordination in (43.3%) were present. Mean duration of symptoms was 30.6 days; return to school was 23.9 days. 73.3% of patients would return to sport within 3 months (mean=34.6 days).ConclusionsSport-related concussion symptoms resolved ≥30 days after injury confirming prolonged symptoms in an adolescent population, affecting return to school and sport. Future larger similar prospective studies may identify associations between past medical history or clinical exam findings and symptom duration, return to school and sport.Competing interestsNone.
Symptom progression and relation to physical and cognitive activities based on ecologic momentary assessment of patients following concussion
Authors: Wiebe Douglas J , Grady Matthew F , Nance Michael , Houseknecht Eileen , Master Christina L 
Published: November 2017

ObjectiveTo use ecologic momentary assessment to measure and compare daily reports of physical/cognitive activity and symptoms among youth for 2 weeks after sustaining a concussion.DesignProspective cohort study, with patients reporting to random prompts on a handheld 3 times daily and wearing an accelerometer.SettingSpecialty concussion program within a large regional paediatric healthcare network.Participants34 patients, ages 11–17 years with the diagnosis of concussion seen in the concussion program.Independent variablesMeasurements of daily physical activity (step count) and cognitive activity (composite score of texts sent, screen time minutes, reading minutes, school attendance).Outcome measuresDaily symptoms on the Post Concussion Symptom Scale (PCSS).Main resultsStudy subjects were enrolled a median of 6 days post-injury (range 5–13 days). Numerous profiles were observed, including being initially highly (PSCC≥20) or less symptomatic (PSCC ≤ 10), initially highly (steps>6000) or less physically active (steps<3000), and initially highly or less cognitively active. Levels of activity also varied greatly over follow-up. Symptoms declined in most subjects regardless of activity levels during follow-up. Regardless of activity levels, most patients were not symptomatic (PCSS ≤ 8) at the end of the follow-up period.ConclusionsWe found evidence that initial levels of physical and cognitive rest vary greatly in the days immediately following a first visit, and over subsequent weeks, but most patients were asymptomatic after 4 weeks from injury. This protocol can be used in larger studies designed to fully test whether and how physical and cognitive rest and their timing following injury affect recovery.Competing interestsNone.
55 the recognition of paediatric sports related concussion (5–16 year olds), initial management and advice among london based emergency medicine trainees
Authors: Hornby Catherine , England Mike , Medici Akbar de , Kipps Courtney 
Published: November 2017

ObjectiveThis study aimed to investigate knowledge of paediatric concussion amongst emergency medicine trainees, testing the hypothesis that emergency medicine trainees lack sufficient knowledge to competently assess, diagnose and manage sports-related paediatric concussion.Designcross-sectional questionnaire survey.SettingSecondary care emergency medicine departments.ParticipantsAll emergency medicine trainees in one geographical training region in the UK were invited to participate.Outcome measuresoccupational grade, years of experience, history of specific concussion training, awareness of head injury guidelines, perceived knowledge and confidence in concussion diagnosis and management.Main resultsSixty questionnaires were returned. Across all training grades, the mean correct response score on questions of diagnosis, assessment and management of concussion was 73.4%. Nearly 70% of trainees were not aware of any concussion guidelines, and only 10% had attended a course or received training regarding concussion. There was a negative correlation between awareness of guidelines and perceived confidence (r=−0.50 p<0.001), and knowledge in diagnosis and management of concussion (r=−0.51, p<0.001). The majority (91.7%) of the participants would like further education on concussion management, with an online learning module being the preferred format (71.7%).ConclusionsThe study revealed insufficient level of knowledge and confidence in the assessment, diagnosis and management of paediatric concussion among emergency medicine trainees. None of the variables studied statistically predicted knowledge score. Additional concussion-specific education would be beneficial to optimise trainees’ knowledge of paediatric concussion.Competing interestsNone.
A history of multiple concussions does not alter the transcranial doppler-based assessment of the neurovascular coupling response
Authors: Smirl Jonathan D , Wright Alexander D , Bouilane Kevin , Bryk Kelsey , Donkelaar Paul van 
Published: November 2017

ObjectiveTo determine how a history of 3+ concussions alters elevations in cerebral blood velocity (CBV) in the posterior cerebral artery (PCA) during visual tasks.DesignRetrospective Cohort.SettingLaboratory.Participants136 male contact-sport athletes (19.1±1.4 years, 66 football, 70 hockey) were recruited; 39 presented with 0 previous concussions, 16 with 3+ previous concussions; exclusion criteria included history of concussion within 6 months.InterventionTranscranial Doppler ultrasound indexed PCA-CBV during a series of visual tasks. Participants closed their eyes (20-seconds) and, when prompted, opened their eyes to complete a visual task (40-seconds). Testing occurred prior to the start of their athletic season. The visual trial raw traces were averaged together to enhance the signal-to-noise ratio of outcome measurements. The independent variable tested was concussion history.OutcomesEyes-closed CBV (cm/s), peak elevation in CBV after eyes-open (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 resultsIndependent samples T-Tests indicated there were no effects of concussion history on any outcome: Eyes-closed CBV (p=0.950), peak CBV (p=0.903), % CBV elevation (p=0.593), and AUC (p=0.718).ConclusionsA history of multiple concussions does not alter the cerebrovasculature’s ability to maintain nutrient delivery required for visual challenges in cortical areas supplied by the PCA. This is an important finding; despite the long-term neurocognitive deficits associated with a history of concussions, the transcranial Doppler assessment of neurovascular coupling appears intact for this population of younger adult contact-sport athletes.Competing interestsNone.
Long-term impact of concussional head injury on cognitive functioning in retired australian rules footballers: a preliminary report of a 25-year follow-up
Authors: Maddocks David , Blaine Hannah , Inge Philipa , McCrory Paul , Saling Michael 
Published: November 2017

Objectivethe research involved a 25-year neuropsychological follow-up of an Australian Rules football (ARF) cohort studied originally by Maddocks and Saling (1996). The primary aim was to assess whether there is a long-term impact of concussional head injury on cognitive function.MethodIn addition to those tests originally administered (Digit Symbol Substitution Test; Paced Auditory Serial Addition Test; Four Choice Reaction Time), the California Verbal Learning Test, Trail Making Test, Controlled Oral Word Association Test, Victoria Stroop Test, and selected self-report functional health and well-being, and quality of life measures were used. Thirty former Australian Football League players, aged from 44-56 years (Mage=48.8 years), completed both the neuropsychological testing and psychosocial questionnaires.Main resultsConcussional history did not have an influence on cognitive or psychosocial functioning in this sample of retired ARF players. There was no evidence of deterioration in cognitive function across time. Irrespective of concussional history, age appeared to be an important contributor to subjective memory complaints, with older participants reporting greater memory concerns.ConclusionsIn this sample of retired ARF players no evidence of objective cognitive change was found over the time period in which CTE is said to evolve. This research shows, for the first time that long-term cognitive and psychosocial outcome in ARF players may be unrelated to career-long concussional history.Competing interestsDavid Maddocks and Paul McCrory are members of the AFL Concussion Working Party.None.
Wooden heads and glass jaws: the long-term effects of recurrent concussion and american football exposure on resting state networks
Authors: Clark Michael , Mihalik Jason , Guskiewicz Kevin 
Published: November 2017

ObjectiveTo elucidate the association between recurrent concussion and subconcussive head impacts andb the efficiency of resting state neural networks in retired American football athletes.DesignCross-sectional.Subjects32 former college football athletes and 32 former professional football athletes matched on age, position, and self-reported concussion history (age: 58.5±3.6 y). Of those, 61 subjects had quality imaging data (31 College, 30 Professional). Subjects were stratified by concussion history (High, 3+, N=31; Low, 0–1, N=30).Outcome measuresIVs: Concussion history (Low/High) and football exposure (College/Professional). DVs: Mean local efficiency (LE) and clustering coefficients (CC) for seven anatomically defined neural subnetworks: frontal, temporal, occipital, medial temporal, subcortical, parietal, and cerebellar. Outcomes were analysed across several correlational thresholds (r=0–0.9).ResultsThe high concussion group had lower frontal LE and CC than the low concussion group (Effect size range: 0.260 – 0.437, P<0.05). A crossover history-by-exposure interaction was observed in the cerebellar network (P=0.0063), such that former college athletes with high concussion history demonstrated lower LE and CC than college athletes with low concussion history. Interestingly, professional athletes with high concussion history demonstrated greater LE and CC than those with low concussion history. No other associations were observed across the five remaining neural networks.ConclusionsThese data challenge the notion that subconcussive head impact exposure is linked to long-term neurological dysfunction. Our data point to a potential heightened cerebellar network resiliency among retired professional athletes with a high number of concussions. Subconcussive head impact exposure alone does not appear to affect widespread cortical and cerebellar network function among retired American football athletes.Competing interestsNone.Member of the Mackey-White committee of the NFL Players Association and member of the Head, Neck, and Spine Committee of the NFL.
Comparing performance on baseline computerized neurocognitive and balance
Authors: Weber Michelle L , Schmidt Julianne D , Hoffman Nicole L 
Published: November 2017

ObjectiveTo compare head impact severity between high and low performers on baseline neurocognitive and balance assessments in collegiate American football athletes.DesignProspective cohort.SettingOn-field/Concussion Research Laboratory.ParticipantsThirty collegiate American football players (height: 187.0 cm, 95% CI: 184.6, 189.4; mass: 105.4 kg, 95% CI: 99.3, 111.6; age: 21.0 years, 95% CI: 20.5, 21.5).InterventionsParticipants completed a baseline neurocognitive assessment (Immediate Post-Concussion Assessment and Cognitive Test) and balance exam (Sensory Organization Test). Participants wore accelerometers (Head Impact Telemetry System) to capture measures of severity for 13,537 head impacts.Outcome measuresGroups were divided into higher and lower performance groups using a median split for independent variables including composite neurocognitive (verbal memory, visual memory, processing speed, reaction time and impulse control) and balance performance. Random intercepts general linear models were used to compare linear acceleration (g), rotational acceleration (rad/s2), and Head Impact Technology severity profile (HITsp-unitless) between higher and lower performing groups (α=0.05). Position group was included in all models.Main resultsAthletes with slower reaction time had a trend towards higher linear acceleration (higher 26.4, 95% CI: 24.6, 28.3; lower 24.6, 95% CI: 23.7, 25.7;p=0.080) and significantly higher rotational acceleration (higher 1020.2, 95% CI: 990.1, 1051.2; lower 946.6, 95% CI: 910.0, 984.8;p=0.003).ConclusionsAthletes with slower reaction time may be slower to prepare for collisions, resulting in higher magnitude head impacts. Clinicians should recognize athletes with slower reaction time on baseline neurocognitive assessments and understand the on-field implications. Research is needed to further identify a reaction time threshold between high and low performers, and risk of sustaining higher magnitude head impacts.Competing interestsNone.