bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential Involvement of Fas and Its Ligand in the Pathogenesis of Hashimoto's Thyroiditis
Authors: Giordano Carla , Stassi Giorgio , De Maria Ruggero , Todaro Matilde , Richiusa Pierina , Papoff Giuliana , Ruberti Giovina , Bagnasco Marcello , Testi Roberto , Galluzzo Aldo
Published: November 2017

The mechanisms responsible for thyrocyte destruction in Hashimoto's thyroiditis (HT) are poorly understood. Thyrocytes from HT glands, but not from nonautoimmune thyroids, expressed Fas. Interleukin-1β (IL-1β), abundantly produced in HT glands, induced Fas expression in normal thyrocytes, and cross-linking of Fas resulted in massive thyrocyte apoptosis. The ligand for Fas (FasL) was shown to be constitutively expressed both in normal and HT thyrocytes and was able to kill Fas-sensitive targets. Exposure to IL-1β induced thyrocyte apoptosis, which was prevented by antibodies that block Fas, suggesting that IL-1β-induced Fas expression serves as a limiting factor for thyrocyte destruction. Thus, Fas-FasL interactions among HT thyrocytes may contribute to clinical hypothyroidism.
Stable Core Gut Microbiota across the Freshwater-to-Saltwater Transition for Farmed Atlantic Salmon
Authors: Rudi Knut , Angell Inga Leena , Pope Phillip B. , Vik Jon Olav , Sandve Simen Rød , Snipen Lars-Gustav
Published: November 2017

Gut microbiota associations through habitat transitions are fundamentally important yet poorly understood. One such habitat transition is the migration from freshwater to saltwater for anadromous fish, such as salmon. The aim of the current work was therefore to determine the freshwater-to-saltwater transition impact on the gut microbiota in farmed Atlantic salmon, with dietary interventions resembling freshwater and saltwater diets with respect to fatty acid composition. Using deep 16S rRNA gene sequencing and quantitative PCR, we found that the freshwater-to-saltwater transition had a major association with the microbiota composition and quantity, while diet did not show significant associations with the microbiota. In saltwater there was a 100-fold increase in bacterial quantity, with a relative increase ofFirmicutesand a relative decrease of bothActinobacteriaandProteobacteria. Irrespective of an overall shift in microbiota composition from freshwater to saltwater, we identified three core clostridia and oneLactobacillus-affiliated phylotype with wide geographic distribution that were highly prevalent and co-occurring. Taken together, our results support the importance of the dominating bacteria in the salmon gut, with the freshwater microbiota being immature. Due to the low number of potentially host-associated bacterial species in the salmon gut, we believe that farmed salmon can represent an important model for future understanding of host-bacterium interactions in aquatic environments.

IMPORTANCELittle is known about factors affecting the interindividual distribution of gut bacteria in aquatic environments. We have shown that there is a core of four highly prevalent and co-occurring bacteria irrespective of feed and freshwater-to-saltwater transition. The potential host interactions of the core bacteria, however, need to be elucidated further.
Microbially Mediated Coupling of Fe and N Cycles by Nitrate-Reducing Fe(II)-Oxidizing Bacteria in Littoral Freshwater Sediments
Authors: Schaedler Franziska , Lockwood Cindy , Lueder Ulf , Glombitza Clemens , Kappler Andreas , Schmidt Caroline
Published: November 2017

Nitrate-reducing iron(II)-oxidizing bacteria have been known for approximately 20 years. There has been much debate as to what extent the reduction of nitrate and the oxidation of ferrous iron are coupled via enzymatic pathways or via abiotic processes induced by nitrite formed by heterotrophic denitrification. The aim of the present study was to assess the coupling of nitrate reduction and iron(II) oxidation by monitoring changes in substrate concentrations, as well as in the activity of nitrate-reducing bacteria in natural littoral freshwater sediment, in response to stimulation with nitrate and iron(II). In substrate-amended microcosms, we found that the biotic oxidation of ferrous iron depended on the simultaneous microbial reduction of nitrate. Additionally, the abiotic oxidation of ferrous iron by nitrite in sterilized sediment was not fast enough to explain the iron oxidation rates observed in microbially active sediment. Furthermore, the expression levels of genes coding for enzymes crucial for nitrate reduction were in some setups stimulated by the presence of ferrous iron. These results indicate that there is a direct influence of ferrous iron on bacterial denitrification and support the hypothesis that microbial nitrate reduction is stimulated by biotic iron(II) oxidation.

IMPORTANCE
The coupling of nitrate reduction and Fe(II) oxidation affects the environment at a local scale, e.g., by changing nutrient or heavy metal mobility in soils due to the formation of Fe(III) minerals, as well as at a global scale, e.g., by the formation of the primary greenhouse gas nitrous oxide. Although the coupling of nitrate reduction and Fe(II) oxidation was reported 20 years ago and has been studied intensively since then, the underlying mechanisms still remain unknown. One of the main knowledge gaps is the extent of enzymatic Fe(II) oxidation coupled to nitrate reduction, which has frequently been questioned in the literature. In the present study, we provide evidence for microbially mediated nitrate-reducing Fe(II) oxidation in freshwater sediments. This evidence is based on the rates of nitrate reduction and Fe(II) oxidation determined in microcosm incubations and on the effect of iron on the expression of genes required for denitrification.
Complete Mitochondrial Genome Sequence of
Aethina tumida
(Coleoptera: Nitidulidae), a Beekeeping Pest
Authors: Duquesne Véronique , Delcont Aurélie , Huleux Anthéa , Beven Véronique , Touzain Fabrice , Ribière-Chabert Magali
Published: November 2017

We report here the full mitochondrial genome sequence of
Aethina tumida
, a Nitidulidae species beetle, that is a pest of bee hives. The obtained sequence is 16,576 bp in length and contains 13 protein-coding genes, 2 rRNA genes, and 22 tRNAs.
Genome Sequences of 34 Shiga Toxin-Producing Escherichia coli Isolates from Swine and Other Sources
Authors: Baranzoni Gian Marco , Fratamico Pina M. , Kim Gwang-Hee , Reichenberger Erin R. , Funk Julie A. , Manning Shannon D. , Bosilevac Joseph M.
Published: November 2017

Shiga toxin-producing
Escherichia coli
(STEC) bacteria are foodborne pathogens that can be carried by various animals. The swine STEC population is partially composed of host-specific strains that are often not well characterized. In this work, the genome sequences of a number of swine STEC strains are presented.
Draft Genome Sequence of the First Confirmed Isolate of Multidrug-Resistant Mycobacterium tuberculosis in Tasmania
Authors: Gautam Sanjay S. , Mac Aogáin Micheál , O’Toole Ronan F.
Published: November 2017

The spread of multidrug-resistant (MDR) tuberculosis (TB) has become a major global challenge. In 2016, Tasmania recorded its first known incidence of MDR-TB. Here, we report the draft whole-genome sequence of the
Mycobacterium tuberculosis
isolate from this case, TASMDR1, and describe single-nucleotide polymorphisms associated with its drug resistance.
Draft Genome Sequences of Two Lactobacillus casei Strains Isolated from Cheddar Cheese and a Fermented Milk Drink
Authors: Nahar Akhikun , Baker Anthony L. , Bowman John P. , Britz Margaret L.
Published: November 2017

MiSeq Illumina shotgun sequencing technology was used to sequence two
Lactobacillus casei
strains, designated strains GCRL 163 and MJA 12. The estimated genome sizes for GCRL 163 and MJA 12 were 2.9 Mb and 3.1 Mb, with 46.35% and 46.31% GC contents, respectively.
Draft Genome Sequence of a Mexican Community-Associated Methicillin-Resistant Staphylococcus epidermidis Strain
Authors: Magaña-Lizárraga José Antonio , Hernández-Peinado Jessica Victoria , Ahumada-Santos Yesmi Patricia , Parra-Unda Jesús Ricardo , Uribe-Beltrán Magdalena de J. , Gómez-Gil Bruno , Báez-Flores María Elena
Published: November 2017

We report here the first draft genome sequence of a Mexican communitarian methicillin-resistant
Staphylococcus epidermidis
(MRSE) strain whose genome harbors a wide variety of resistance determinants. The availability of this genome will allow the study of antibiotic resistance in Mexican staphylococci from a genomic perspective.
Draft Genome Sequence of Staphylococcus aureus 4185, a Strain That Produces Aureocyclicin 4185
Authors: Francisco Márcia Silva , Farias Felipe Miceli , Santos Ilana Nascimento Sousa , Marques-Bastos Selda Loase Salustiano , Albano Rodolpho Mattos , Bastos Maria do Carmo Freire
Published: November 2017

The draft genome sequence of the aureocyclicin 4185-producing strain
Staphylococcus aureus
4185 is presented. The assembly contains 2,789,721 bp and a G+C content of 32.8%. Genome analysis allowed us to determine the complete sequence of the bacteriocinogenic plasmid pRJ101 and to find another bacteriocin gene cluster encoded on the bacterial chromosome.
Safe return to play after protocol-based concussion management by a team therapist: a prospective study
Authors: Frémont Pierre , Castonguay Édith , Pepe-Esposito Francesco , Beaudoin-Hamel Vincent , Desloges Catherine , Dionne Monika , Gourde Marie-Christine , Hogue Benoit , Lanthier-Plante Jérémie , Provencher Maxime , Quirion Mikael
Published: November 2017

Objective

To analyse the safety of a multidisciplinary concussion management protocol where a team therapist is involved in return-to-play (RTP) decisions.

Design

Prospective, pre- post-intervention cohort study over 4 seasons of competition

Setting

School-based American football program (4 teams; grades 8–12)

Participants:

672 players x year (11–17 year old) for a total of 27741 athlete-exposure.

Intervention

A protocol based on the Concussion In Sport Group recommendations was implemented. A computerised neuropsychological (CNP) test was used at baseline and prior to clearance for unrestricted training. For seasons 1–2, the protocol required the team physician to make all RTP decision while defined criteria allowed the team physiotherapist to make the vast majority of the RTP decisions over seasons 3–4.

Outcome measures

The primary outcome was the early recurrence (ER) of concussion symptoms following RTP (defined as during the same season).

Results

A total of 119 concussions were identified (55 and 64 for the first and last 2 seasons, respectively; incidence rate 4, 3: 1000 athlete-exposures). At the time of the first clearance decision, the CNP test contributed to a negative RTP decision in 67% of cases. During seasons 1–2 no ER was observed. During season 3 one injury unrelated to football resulted in one case of ER prior to clearance and, during season 4, one case of ER occurred during the second game, 11 days after clearance.

Conclusions

Safe management of concussions was achieved whether the team physician or the team therapist was responsible for the application of the terms of the protocol.

Competing interests

Pierre Frémont chair of the Canadian Concussion Collaborative.

Édith Castonguay is the physiotherapist for the football program described in this study.

Francesco Pepe-Esposito is Head coach of the football program described in this study.

None.
Investigating a 7-day baseline while establishing healthy scat3 symptom frequency and severity
Authors: Robinson Michael , Mc Elhiney Danielle
Published: November 2017

Objective

The reliability of a concussion symptom checklist can become compromised by external conditions (weather, medical conditions, stress, medications, etc.). This study assessed the day-to-day reliability of the SCAT3 Symptom Evaluation to determine if participants provide consistent responses in addition to determining the frequency and severity of the 22 symptoms in a non-concussed, adult, athletic population.

Design

Repeated measure observational design.

Setting

This study was conducted at a University in Ohio, U.S.A.

Participants

52 volunteers (18 to 30 years), self-identified as an athlete and had not suffered a concussion in the past 6 months.

Intervention

Participants completed the SCAT3 Symptom Evaluation at prescribed times through the day over a 7 day period. Participants were randomly assigned to two equal groups, alternating between completing the SCAT3 Symptom Evaluation twice (at wake up and before bed) or once (in the afternoon) each day.

Outcome measures

Severity and frequency of each of the 22 symptoms over a 7 day period.

Main results

The single measure intraclass correlation coefficient was 0.496 (95% CI=0.382 to 0.620, SEM=0.134) for the frequency of symptoms and 0.438 (95% CI=0.325 to 0.568, SEM=0.221) for the sum of the symptom severity over 7 days.

Conclusions

The results demonstrated poor day-to-day reliability for the reporting of the frequency and severity of symptoms. All of the 22 symptoms on the SCAT3 Symptom Checklist were reported by at least one participant with the most commonly reported symptoms being fatigue or low energy, drowsiness, and headaches.

Competing interests

None.
Eye tracking a biomarker for concussion in the paediatricpediatric population
Authors: Samadani Uzma , Zahid Abdullah Bin , Lockyer Julia , Dammavalam Vikalpa , Grady Matthew , Nance Michael , Scheiman Mitchell , Master Christina L
Published: November 2017

Objective

The study aims to validate eye movement tracking performed without a baseline study as a biomarker for concussion in a paediatric population.

Design

This is a cross-sectional case control study of patients diagnosed with concussion in a referral centre compared to non-concussed controls.

Methods

Eye movements were recorded with an SR Research Eyelink 1000 eye tracker while a 220-second video was played. Eye tracking metrics were compared to Acute Concussion Evaluation (ACE) scores and clinical assessments of convergence and accommodation.

Results

56 children with concussions (mean age of 13 years), as defined by symptom presence following an impulsive injury to the brain were evaluated at a mean of 22 weeks post-injury. Twelve eye tracking metrics were significantly different between concussed children and 83 uninjured controls. A model built on a balanced sub-sample to classify concussion based on eye tracking achieved an AUC of 0.854 (sensitivity 71.9%; specificity 84.4%). Two metrics were significant predictors of abnormal near point convergence (NPC) and accommodation. The model built to classify concussion based on NPC status achieved a specificity of 95.8% and a sensitivity of 57.1%. Reduced binocular amplitude of accommodation had a spearman correlation of 0.752 (p-value<0.001) with NPC. Seven eye tracking metrics were found to have a strong correlation (R=0.781) with binocular amplitude of accommodation.

Conclusions

Eye tracking reliably detected concussion and convergence and accommodative abnormalities in the paediatric population. We propose that eye tracking without baseline assessment may serve as an objective measure of concussion in paediatric patients.

Competing interests

Uzma Samadani has submitted intellectual property describing the technology utilised in this paper.

These patents are owned by NYU, the VA and HCMC and licensed to Oculogica Inc., a company in which all of the above parties have an equity interest
Change in concussion measures in division i men’s lacrosse players who did not report a concussion
Authors: Miyashita Theresa , Diakogeorgiou Eleni
Published: November 2017

Objective

The purpose of our study was to investigate if a significant change in concussion baseline measurements occur in athletes who did not reportedly sustain a concussion.

Design

Cohort Study

Setting

Division I University

Participants

22 Division I Men’s Lacrosse players’ data were used for the BESS test (age=19.95, ± 0.99) and 26 Division I Men’s Lacrosse players’ data were used for the CNS Vital Signs test (age=20.15, ± 1.05)

Interventions

calendar year; 2015 competitive lacrosse season

Outcome measures

Repeated-measures ANOVAs and paired samples t-tests determined the change in concussion baseline measurement scores from pre-season 2015, post-season 2015, and pre-season 2016. BESS scores and the ten tests associated with CNS Vital Signs were analysed for changes.

Main results

There were increases in the number of errors committed during the foam double leg stance (p=0.017) and foam tandem stance (p=0.007) from pre-season 2015 to pre-season 2016. 60% of of the tests within the CNS Vital Signs testing battery resulted in significant improvements from pre-season 2015 to pre-season 2016: psychomotor speed (p=0.031), executive function (p=0.003), cognitive flexibility (p=0.004), reaction time (p=0.004), simple reaction time (p=0.002), and shifting attention correct reaction time (p=0.016).

Conclusions

Concussion baseline measurements should be repeated on an annual basis to improve accuracy when implementing a return-to-play protocol following a concussion.

Competing interests

None
Classifying invalid baseline scores
Authors: Mrazik Martin , Naidu Dhiren
Published: November 2017

Objective

Analysis of a proposed method for classifying invalid baseline tests in professional football players.

Design

Retrospective cross-sectional study.

Setting

Professional Canadian Football.

Participants

Four hundred and seventy-eight male football players from the Canadian Football League.

Intervention

A proposed system to classify invalid baselines used the lowest 5% of domain scores from baseline Immediate Post-concussion Assessment and Cognitive Testing (ImPACT), King Devick, and SCAT3 (balance and SAC totals) coupled with the highest 5% of total symptom report from SCAT3. Impairment on 2 or more scores was classified as invalid (INV).

Main Outcome measures

Descriptive statistics, correlation and stepwise regression analysis.

Main Results

Correlations revealed significant relationships (p<0.05) between INV and all 5 domains of ImPACT and SCAT3 symptom score, but not for King Devick and SCAT3 balance and SAC totals. The forward stepwise regression yielded a significant model (R2=0.23, F(4, 473)=35.7, p<0.001). Significant predictors included visual memory, reaction time, impulse control, and verbal memory from ImPACT. This system classified 3.7% of participant with invalid baseline tests.

Conclusions

There are few published methodologies used to classify invalid baseline tests in spite of their widespread use. Valid baseline tests are essential for proper identification and management of concussion. Our proposed method identified 4 ImPACT domains scores that predict invalid baseline scores. This system may be helpful in classifying invalid baseline tests with commonly used baseline test measures although more research is required to validate this method.

Competing interests

None.
Genotypes are related to neurocognitive performance but not concussion history in collegiate student-athletes
Authors: E Hall Eric , D. Cochrane Graham , Sundman Mark , C Kostek Matthew , Patel Kirtida , P Barnes Kenneth , J Ketcham Caroline
Published: November 2017

Background

Single-nucleotide polymorphisms (SNPs) of neurologically relevant genes play a role in concussions from increasing susceptibility or hampering cognitive performance.

Objective

The purpose of this study was to investigate the effects of polymorphisms of APOE, APOE promoter, COMT and DRD2 on baseline neurocognitive function and concussion history in collegiate student-athletes.

Design

Cross-sectional.

Setting

Collegiate campus in North Carolina.

Participants

262 (194 males, 68 females) collegiate student-athletes.

Assessment of risk factors

Buccal mucosa swabs were collected from participants. SNP genotyping was run on all samples to determine APOE, APOE promoter, COMT, and DRD2 genotypes. Participants were split into three groups based on their genotypes for each gene.

Outcome measures

Participants completed the Immediate Post-Concussion Assessment and Cognitive Testing neurocognitive assessment which generated composite scores on Verbal Memory, Visual Memory, Visuomotor Speed, and Reaction Time as well as Impulse Control

Results

None of the genotype variables influenced number of concussions (p>0.05). MANOVA analysis determined no differences for APOE promoter and DRD2 genotypes (p>0.05). There were statistical differences for APOE for Visuomotor composite (APOE-e3 (m=41.2, %95 CI [40.8, 42.1]) vs e4 (m=39.1, %95 CI [37.8, 40.5], p=0.017) and Reaction Time (APOE-e4 (m=0.62, %95 CI [0.60, 0.64]) was different than both e2 (m=0.57, %95 CI [0.54, 0.60] and e3(m=0.58, %95 CI [0.56, 0.59], p<0.005). There were also differences for COMT for Impulse Control (Val/Val (m=6.2 %95 CI [5.4, 7.1]) was different Val/Met (m=4.7, %95 CI [4.1, 5.2] and Met/Met (m=4.7, %95 CI [3.8, 5.6], p<0.02).

Conclusions

APOE and COMT single nucleotide polymorphisms lead to significant differences in neurocognitive performance at baseline but not concussion history.

Competing interests

None.
Examining the cumulative effect of repetitive head-impacts on the ability to inhibit a motor response
Authors: Bryk Kelsey , Alexander D Wright , Jakovac Michael , Smirl Jonathan D , Paul van Donkelaar
Published: November 2017

Objective

To examine how a season of sub-concussive head-impact exposures influence a measure of response-inhibition in contact-sport athletes.

Design

Prospective cohort

Setting

Laboratory

Participants

Twenty-five contact-sport athletes (20.3±1.3 years) performed a response-inhibition task prior to and following the competitive season. Each player wore an adhesive accelerometer (X2Biosystems) during games. Players were excluded if they sustained a concussion during the season.

Interventions

To probe response-inhibition, an object hit-and-avoid sensorimotor task (KINARM) was performed. This 2.5 minute task entailed the successful hitting of two target shapes while avoiding six other distractor shapes. Players were divided into tertiles (high, medium, low; n=8) based on cumulative number of 20g+ head impacts, cumulative peak linear acceleration (cPLA), and cumulative peak rotational acceleration (cPRA). Comparisons of response-inhibition performance were made between high and low tertiles.

Outcome measures

Pre-post changes in number of targets hit, distractors hit, total cancelled movements towards pursued distractors (CPDs), and total task accuracy (percent) were recorded for the KINARM task.

Results

Independent t-tests indicated no significant differences between the high and low tertiles on the KINARM task despite the high tertile group experiencing 4-times greater head impacts throughout the season. There was a trend for greater KINARM task improvement from pre-to-post-season in the bottom tertile, as reflected by the increase in CPDs in their post-season measures (cumulative number: p=0.06, CI=[−16.2148519, 0.7148519]).

Conclusions

These findings reveal that one season of repetitive sport-related head impacts does not appear to have a significant effect on an athlete’s ability to inhibit a motor response.

Competing interests

All authors have no competing interests to declare.
Gp and emergency medicine trainee’s knowledge of appropriate diagnostic and treatment options for concussion in the west of ireland
Authors: Gilmartin Stephen , Waters Aine , Harris Karen
Published: November 2017

Objective

To Investigate GP and Emergency medicine trainee’s knowledge and application of concussion treatment and diagnostic options in the west of Ireland

Design

Cross Sectional

Setting

Sligo and Galway University Hospitals, Ireland

Participants

37 GP and 8 emergency medicine trainees. The doctors were all working in an Emergency department or community GP Practice

Interventions

All trainees were instructed to complete a questionnaire in person without any aids or educational advice.

Outcome measures

We aimed to establish baseline trainee knowledge of concussion and also their appropriate use of current diagnostic and treatment guidelines.

Main Results

13% of those asked had received formal concussion training. Only 35% used any formal concussion assessment tool, SCAT3 was the most common. 35.6% and 15.6% of trainees prescribe physical and cognitive rest respectively to all of their concussion patients. All of his has led to only 20% of those questioned providing a return to play plan to their patients following concussion diagnosis. One sample t-tests found all of these findings were statistically significant (P<0.05).

Conclusions

Our results show that despite concussion’s increasing media profile worldwide, GP and emergency medicine trainee’s in the west of Ireland remain ill informed of the appropriate diagnostic and treatment protocols. It is felt that this is likely representative of trainee knowledge levels nationwide, although a larger demographic is needed to prove this. In conjunction with acquired brain injury Ireland we have created a new concussion pathway for Sligo University Hospital which includes diagnostic aids and outpatient treatment options for our locality.

Competing interests

None
Integration of computerised dynamic posturography (equitest) in the rehabilitation process after concussion
Authors: Karin Mani , Nina Feddermann , Cornelia Meier , Alfred Müller , Dominik Straumann , Cornelia Meier , Mario Bizzini
Published: November 2017

Objective

Vertigo, dizziness and visual problems are among the main symptoms of a prolong course after concussion. Adequate diagnostic tools are rare. The computerized sensory organization test (SOT) differentiates the sensory integration between somatosensory, vision, vestibular and visual preference. This analysis may help to create an individual rehabilitation program and observe the progress.

Design

Case series.

Setting

Rehabilitation center.

Participants

Among 31 post-injury tested athletes with a diagnosed concussion 5 male professional players completed a follow-up test by the end of April 2016. Interventions: 5 players performed a post-injury baseline on the computerized dynamic posturograph (Equitest) and repeated the test as follow-up after personalized vestibulo-oculomotor therapy and improvement of symptoms during the rehabilitation process.

Outcome measures

Outcome measures were total score (calculated by 6 SOT conditions) and identification of the integrational deficits (calculated by results of sensory analysis). Both values serve to guide and monitor the individual rehabilitation.

Main results

At post-injury baseline a deficient total score and vestibular impairment was verified in all 5 athletes. After specific individualized vestibulo-oculomotor therapy and a significant reduction of symptoms the follow-up test demonstrated improvement in total score (22% ± 10% SD) to a point where entering intensive training (return to play protocol stage 3) was recommended. Regarding the vestibular system patients improved their score 57% ± 20% SD.

Conclusions

The computerized SOT can be a useful tool to identify specific sensory deficits and to help specify post-injury therapy and observe the individual rehabilitation process regarding the return to play protocol. Further research is required.

Competing interests

None.
Single-task and dual-task tandem gait test performance after concussion
Authors: Howell David R , Osternig Louis R , Chou Li-Shan
Published: November 2017

Objective

To examine tandem gait test (TGT) performance during single-task and dual-task conditions.

Design

Prospective, longitudinal observational study

Setting

Motion analysis laboratory

Participants

Ten post-concussion (30% F, 19.0 [95% CI=15.6–22.4] years) and 7 control (57% F, 20.0 [16.7 -23.3] years) participants completed the TGT in single-task and dual-task conditions within 72 hours of sustaining a concussion and again at 1 week, 2 weeks, 1 month, and 2 months post-injury. Exclusion criteria included a current lower extremity injury, diagnosed learning disability, or documented prior concussion within the past year.

Independent variables

TGT trials were performed without (single-task) and while concurrently performing a cognitive test (dual-task).

Outcome measures

Participants completed 3 trials in each condition while whole body motion capture was performed. Outcome variables included the average completion time for the 3 trials, mean center-of-mass gait velocity, and cadence.

Main results

Concussion participants took significantly longer to complete the dual-task TGT than controls (16.4 [13.4 -19.4] vs. 10.1 [6.4 -13.7] seconds) at the 72 hour, 1 week, and 2 week time points (p=.03); single-task TGT times were significantly lower 72 hours post-injury only (p=.04). Cadence was significantly lower for concussion participants across the two month testing period during dual-task TGT (89.5 [68.6 -110.4] vs. 127.0 [97.4 -156.6] steps/minute; p=.04). Mean gait velocity was lower for concussion participants at 72 hours post-injury in both conditions.

Conclusions

Dual-task TGT deficits lasted longer for concussion participants than single-task TGT deficits. Including a secondary task during dynamic assessments of gait after concussion may increase the sensitivity to movement deficits that are undetectable using single-tasks.

Competing interests

The authors have no conflicts of interest to report.
Assessing knowledge and attitudes towards concussion in irish footballers
Authors: Gallagher Connor , Falvey Eanna
Published: November 2017

Objective

To assess current levels of knowledge and attitude towards concussion in Irish soccer players and compare findings with other athletic groups.

Design

Participants completed a paper bases Rosenbaum Concussion Knowledge and Attitude Survey (RoCKAS). Results were collated and analysed using descriptive statistics to look for correlation between player subgroups.

Setting

UCD AFC training facility, Dublin, Ireland.

Participants

Seventy male semi-professional and amateur League of Ireland players. Participants had to be registered players of UCD AFC

Outcome measures

All 70 participants completed the questionnaire and passed the RoCKAS internal validity scale.

Main results

Irish players showed good concussion knowledge, broadly safe attitudes and good symptom recognition awareness. There is a positive association between safer concussion attitudes and player age (Pearson correlation coefficient 0.258, p-value 0.031), although no such relationship existed between attitude and years of playing experience (p>0.05). There were no differences found in either knowledge or attitude in the subgroup of players who have a previous history of concussion. There was no association found between higher levels of player concussion knowledge and higher attitude scores (Correlation co-efficient 0.222, p-value 0.064).

Current study knowledge scores were higher than those of English professional players (p ≤ 0.01) but lower than NCAA hockey players (p ≤ 0.01) but attitude scores across the three groups were similar. (Tables 5&6)1,2Concussed Irish soccer players are less inclined to continue playing in an important game than their amateur rugby union counterparts (4.3% versus 76.0%).3

Conclusion

Safer attitudes surrounding concussion are related to increasing player age, not necessarily playing experience. Higher player knowledge does not necessarily confer safer attitudes towards concussion. Future prevention strategies that serve to only educate players may not be effective unless they tackle the reasons players are likely to engage in unsafe behaviour.

Competing interests

None.

Abstract 160 Table 5

Pearson correletion co-efficient values comparing concussion knowledge (CKI) and attitude (CAI) among study sub groups.

Abstract 160 Table 6

Comparison of current study to previous other studies using the RoCKAS concussion knowledge and attitude questionaire.
Non-linear correlation between cumulative sub-concussive head impact trauma and severity of localised brain white matter changes in college athletes
Authors: John Ralston , Jason Thibado , Woodard Jonathan , Cieslak Matthew , Alex Asturias , Scott Grafton
Published: November 2017

Objective

Test for a dose dependent relationship between cumulative sub-concussive head trauma loading and localised changes of brain white matter in college athletes.

Design

Prospective cohort study

Setting

NCAA Division I Women’s Soccer

Participants

10 players were monitored for head impacts throughout a soccer season using wearable sensors. Linear and rotational accelerations recorded during impacts were processed to calculate the cumulative impact power. Diffusion spectrum imaging (DSI) data were acquired at season start and at 3 additional intervals. 11 age and gender matched control data sets were acquired.

Intervention

One athlete suffered a concussion, was removed from play for neurocognitive testing, and entered a supervised return-to-play protocol.

Outcome measures

Cumulative impact power was used as a measure of the head trauma load accumulated prior to each MRI. Multi-dimensional anisotropy (MDA) values assessed localised severity of white matter changes. Session specific differences between each player’s MDA values and those of the control population were used to relate cumulative impact power and the severity of white matter changes.

Main results

Highly significant clusters of abnormal voxels were observed in athletes with no diagnosed concussion symptoms. Injury severity correlated with cumulative head impact power and demonstrated a pronounced threshold behaviour. MDA diffusion changes were located mainly within the frontal and occipital cortex at the gray-white boundary, and to a lesser degree in deep subcortical areas where there is a higher proportion of crossing fibres.

Conclusions

This cohort demonstrates dose dependent changes in white matter integrity as a function of cumulative sub-concussive head trauma.

Competing interests

SG is supported, in part, by a research grant from X2 Biosystems and a General Electric-National Football League Head Health Challenge award.
Concussion knowledge, attitudes, and perceived level of involvement by american youth sport coaches in concussion management
Authors: Kay Melissa C , Williams Richelle M , Valovich McLeod Tamara C , Register-Mihalik Johna K
Published: November 2017

Objective

To describe concussion knowledge and attitudes of youth sport coaches and relationships among knowledge, attitudes, and perceptions of coach involvement in concussion management.

Design

Cross-sectional survey.

Setting

Youth sport coaches in North Carolina and Arizona.

Subjects

81 youth sport coaches (males: n=69; females: n=11; age=42, IQR=33,45).

Intervention

A validated survey identifying demographics, concussion knowledge, attitudes, and beliefs.

Outcome measures

The primary outcome was perceived level of coach involvement in concussion management. Descriptive and univariable statistics were used to examine knowledge and attitude differences by demographic factors and perceived involvement. Multivariable logistic regression examined associations between knowledge and attitude and perceived level of coach involvement (lower agreement vs. higher agreement).

Results

Knowledge was low-moderate (Median=13/23, IQR=11,14.5), with 75% indicating a loss of consciousness always occurs with concussion. Attitudes were positive (Median=42/42, IQR=40,42). Forty-seven (58%) strongly agreed or agreed that coaches should be involved in clinical decision-making. There were no differences in knowledge or attitudes across gender, age, previous concussion education, or previous concussion history. Knowledge and attitude were not correlated (r=0.114; p=0.343). There were no knowledge (Median=13, IQR=12,15 vs. Median = 12, IQR=11,14) or attitude (Median=42, IQR=41,42 vs. Median = 42, IQR=39,42) differences between lower and higher perceived involvement, respectively. No associations were observed in the multivariable model with perceived coach involvement (p>0.05).

Conclusions

Coaches had limited knowledge, but expressed positive attitudes towards concussion. Educational efforts should target both knowledge and attitudes, as these constructs are not related, but are both key to improving the culture concerning concussion.

Competing interests

The project was funded in part by a grant from the National Operating Committee on Standards for Athletic Equipment.
Effect of protective helmets on vision and sensory performance
Authors: Kramer Michelle R , Wasserman Erin B , Teel Elizabeth F , Mihalik Jason P
Published: November 2017

Objective

The purpose of this study was to determine the effect of protective helmets (i.e., football, lacrosse, and ice hockey helmets) on vision and sensory performance.

Design

Experimental cross-over study.

Setting

Clinical research centre.

Subjects

A convenience sample of 24 healthy college-aged males who played American football (n=14), lacrosse (n=5), or ice hockey (n=5) at a minimum of a high school level.

Intervention

Participants completed vision and sensory performance assessments under two counterbalanced conditions: helmeted and unhelmeted.

Outcome measures

The Senaptec Sensory Station assesses visual clarity (LogMAR), contrast sensitivity (logarithm of contrast sensitivity), depth perception (arcsec), near-far quickness (# cycles complete), target capture (threshold response time), perception span (# correct responses), multiple object tracking (tracking capacity), eye-hand coordination (average response time), go/no go (correct minus incorrect hits), and hand reaction time (average reaction time). The overall helmet effect and helmet-by-sport interactions were assessed.

Results

Participants performed 40.7ms slower on eye-hand coordination (95% Confidence Interval [CI]: −66.64, −14.83; p<0.01) and 3.4 points lower on go/no go (95% CI: 1.56, 5.32; p<0.01) when wearing a helmet. Hockey helmets significantly affected visual clarity (95% CI: −0.3701, −0.0883; p=0.01) and hand reaction time (95% CI: −38.67, −9.73; p<0.01), but football and lacrosse helmets did not.

Conclusions

Vision and sensory performance was negatively impacted by wearing a helmet. This inability to see and respond to visual stimuli could have implications for athlete safety and performance, and should be explored further in other at-risk populations such as youth and female athletes.

Competing interests

Kramer: None.

Wasserman: None.

Teel: None.

Mihalik: Dr. Mihalik has an equity interest in Senaptec LLC

Keywords: Concussion, Injury prevention, Vision, Helmet, Facemask
Normative performance on cleveland clinic concussion application for youth, high school and college athletes
Authors: Figler Rick , Linder Susan , Russman Andrew , Cruickshank Jason , Grey Bob , Ozinga Sarah , Lally Maureen , Day Tanujit , Alberts Jay
Published: November 2017

Objective

The utilisation of a multi-factorial approach to evaluating relevant neuro-cognitive and motor function is a critical element in effective and comprehensive concussion management. In this project, normative data were gathered utilising the Cleveland Clinic Concussion (C3) iPad Application in youth, high school and college athletes.

Design

Prospective normative study.

Setting

Field-based.

Participants

Pre-season C3 data were collected in more the 6,500 youth (N=607), high school (N=5415) and college (N=744) athletes; approximately 32% females. Data were collected between Fall 2014 and Spring 2015.

Interventions

NA.

Outcome measures

Neurocognitive assessment modules of C3 include information processing (simple and choice reaction time), attention and working memory (Trail Making Test) and postural stability. Balance is quantified through biomechanical processing of accelerometer and gyroscope data gathered from the iPad during performance of the BESS.

Main results

No gender effects were present for performance on the neurocognitive modules; however, postural stability was significantly worse for youth males compared to female peers (P<0.01). Youth were significantly slower in performance of neurocognitive modules (simple and choice reaction time and Trails; (P<0.0001)). Neurocognitive and postural stability measures were similar across high school and college athletes.

Conclusions

Slower neurocognitive performance in youth relative to older athletes underscores the need to utilise age appropriate normative data in the management of concussion, particularly if no baseline is acquired. The control of postural stability develops at different rates as a function of age and gender, therefore balance assessment across the injury spectrum must utilise specific age-gender normative values.

Competing interests

JLA, SML and SBO have authored intellectual property associated with the mobile application presented in this study.
Level of knowledge and attitude towards sport-related concussion among the general?public
Authors: Gardner Andrew J , Kay-Lambkin Frances , Shultz Sandy R , Iverson Grant L
Published: November 2017

Objective

To investigate attitudes and knowledge of concussion.

Design

Online survey.

Setting

Online questionnaire for the general public.

Participants

Athletes, coaches, parents, sports administrators, and fans, aged 18–80 years.

Assessment

A 75 question survey about the respondents’ concussion knowledge, sources of that knowledge, and attitudes toward injury.

Outcome measures

Frequency of responses.

Main results

Of the 210 respondents who initiated the survey, there were 146 complete datasets. Respondents identified themselves as fans (46%), athletes (43%), coaches (20%), parents (18%), and administrators (13%). Most (85%) claimed to have little to average level of knowledge regarding concussion, the main source of knowledge for 26% of respondents was the media, and 59% had no knowledge of concussion guidelines (only 21% of respondents had heard of the Consensus Statement on Concussion in Sport), although 74% claimed to have knowledge of return-to-play guidelines. When considering reporting a concussion during a game, 77% considered it to be important, 77% beneficial, 74% valuable, 49% brave, and 21% easy. Most respondents indicated that it was extremely serious to experience headaches or dizziness after a blow to the head (54%), extremely important not to participate in physical activity when experiencing signs of concussion (67%), and extremely important to report concussion signs (77%). Respondents’ indicated that it was extremely important for players to be informed about: how concussions occur (67%), concussion prevention (67%), and what to do following concussion (82%). Some respondents (34%) strongly agreed that athletes are undereducated about concussion.

Conclusions

Public knowledge about concussion is modest.

Competing interests

Andrew Gardner has a clinical practice in neuropsychology involving individuals who have sustained sport-related concussion (including current and former athletes). He serves, in a voluntary capacity, as a member of the Australia Rugby Union (ARU) concussion advisory group. He has received travel funding from the Australian Football League (AFL) to present at the Concussion in Football Conference in 2013. Previous grant funding includes the NSW Sporting Injuries Committee, the Brain Foundation and the Hunter Medical Research Institute (HMRI), supported by Jennie Thomas. He is currently funded through the HMRI, supported by Anne Greaves.

Frances Kay-Lambkin: None.

Sandy Shultz: None.

Grant Iverson has been reimbursed by the government, professional scientific bodies, and commercial organisations for discussing or presenting research relating to mild TBI and sport-related concussion at meetings, scientific conferences, and symposiums. He has a clinical and consulting practice in forensic neuropsychology involving individuals who have sustained mild TBIs (including professional athletes).
Racial disparities in concussion knowledge and awareness in american adolescent athletes
Authors: Wallace Jessica , Covassin Tracey , Nogle Sally , Gould Daniel , Kovan Jeffrey
Published: November 2017

Objective

To examine if concussion knowledge and awareness disparities exists between underserved African American (AA) adolescent athletes and Caucasian athletes; and, if disparities exist between AAs with and without access to a full-time athletic trainer (AT).

Design

Cross-sectional.

Setting

Participants from 14 US high schools (9 within underserved, AA communities and 5 within predominantly Caucasian communities) completed a one-time paper and pencil knowledge of concussion questionnaire.

Participants

577 athletes (372 AA, 205 Caucasian). All participants completed concussion education mandated by the government; participants without documentation of completion were excluded.

Intervention

Race and AT access were the independent variables.

Outcome measures

Knowledge of concussion was examined using a validated instrument that included 35 questions. Participants were instructed to identify signs and symptoms of concussion, complications of multiple concussions, and answer questions pertaining to general concussion awareness among distractors. Total knowledge was calculated by summing the number of correct answers out of 35. Scores could range from 0 to 35. Scores closer to 35 represented greater knowledge. Data were analysed with frequency statistics and independent t-tests. Knowledge score was the dependent variable; p=0.05.

Main results

Caucasian adolescents have greater concussion knowledge than AA adolescents (t (2, 575)=5.47, p<0.001). AA adolescents with access to an AT have more knowledge than AAs lacking access to an AT (t (2, 370)=2.58, p=0.01).

Conclusions

Participation of AA adolescents in concussion-risk sports, such as football, is very high; therefore, education efforts in underserved communities must address the knowledge gap and disparity of care.

Competing interests

None.
Tackle technique and body position of the tackler and ball carrier significantly influences head injury risk in rugby union
Authors: Tucker Ross , Hester Ben , Cross Matthew , Kemp Simon , Raftery Martin
Published: November 2017

Objective

Interventions to reduce head injury range from law changes to technique training and education. The effective targeting of such interventions requires that the mechanism of injury be well understood. This study describes the events contributing to head injuries in Rugby Union.

Design

An observational study with a cohort comprised of six professional Rugby Union competitions. Every Head Injury Assessment (HIA) reported during a three-year period was documented and described according to 15 descriptive criteria.

Outcome measures

Descriptive criteria, and combinations thereof, including preceding and inciting event, tackle type, speed, direction and technique-related variables. The incidence of head injury was calculated per 1,000 events for each variable

Main results

611 HIAs were performed in 1,516 matches. 464 HIAs occurred after tackles (1.94 HIAs/1000 tackles). Active shoulder tackles, front-on tackles and high speed tackles have the greatest incidence of head injuries. For any tackle type and tackler position, the lowest incidence of HIAs occurs when the ball carrier is bent at the waist (1.2 HIAs/1000 tackles vs 2.4 and 9.8 HIAs/1000 tackles for upright and falling positions, respectively). For any ball carrier position, the greatest risk of head injury exists when the tackler is upright (2.7 HIAs/1000 tackles vs 1.9 and 1.2 HIAs/1000 tackles for bent at waist and diving, respectively).

Conclusions

Technique components of the tackle, related primarily to the body position adopted by the tackler and ball carrier, significantly influence head injury risk. Interventions may be targeted at improving these variables to reduce head injury incidence in the sport.

Competing interests

The primary author is employed in a scientific and research role by World Rugby (Pty) Ltd, who also funded the research study.