bluuebunny/crossref_metadata_2025_split huggingface dataset:
Examining Changes in Sleep Between Concussed and Healthy Individuals Across Recovery
Authors: Anderson M , Bretzin A C , Petit K M , Tomczyk C P , Savage J L , Covassin T 
Published: July 2019

Abstract

Purpose
To examine changes and the relationship between Pittsburgh Sleep Quality Index (PSQI) scores and the Sport Concussion Assessment Tool–5th Edition (SCAT5) sleep symptom across recovery between concussed and healthy individuals.

Methods
Sixty-eight (18.12±2.6 years; male:n=47, female:n=21; concussed:n=38, healthy:n=30) individuals completed the PSQI and SCAT5 at three times across recovery (≤72 hours of injury, return-to-play (RTP), >one-month after RTP). Two mixed between-within subjects analysis of variance (ANOVAs) evaluated changes in PSQI scores and SCAT5 sleep symptom across recovery between concussed and healthy individuals. Spearman’s rho correlations were used to examine the relationships between the two sleep measures. Significance was set at p≤.05.

Results
There was no significant groupXtime interaction for PSQI scores (Wilks λ=.96, F(2,65)=1.50, p=.23, η2=.04) or SCAT5 sleep symptom (Wilks λ=.93, F(2,65)=2.42, p=.10, η2=.07). There was a significant main effect for time for PSQI scores (Wilks λ=.65, F(2,65)=17.2, p<.001, η2=.35) and SCAT5 sleep symptom (Wilks λ=.88, F(2,65)=4.25, p=.02, η2=.12) with PSQI scores and SCAT5 sleep symptom improving over time. For the SCAT5 sleep symptom there was a significant main effect for group (F(1,66)=13.41, p<.001, η2=.17), with concussed individuals reporting higher SCAT5 sleep symptom (M=0.59, SE=0.1) than healthy controls (M=0.09, SE=0.1). There was no significant correlation between PSQI scores and SCAT5 sleep symptom ≤72 hours (r=.15, p=.36), but there were significant correlations at RTP (r=.38, p=.02) and >one-month (r=.43, p=.01).

Conclusion
Global sleep quality changes throughout recovery and may influence post-concussion outcomes. Utilizing a specialized sleep measure along with sleep-related symptoms may be beneficial to healthcare professionals, specifically during acute concussion management.
Middle School Children with Attention-Deficit/Hyperactivity Disorder Have a Greater Concussion History
Authors: Iverson G L , Kelshaw P M , Cook N E , Caswell S V 
Published: July 2019

Abstract

Purpose
Examine lifetime history of concussions in middle school student athletes who have attention-deficit/hyperactivity disorder (ADHD).

Methods
A sample of 1,037 students from nine middle schools in Virginia, USA (ages 11 to 14, M=12.6, SD=0.93; 45.8% girls) underwent baseline/pre-season assessments during the 2017-2018 academic year and self-reported their health history, including whether or not they had been diagnosed with ADHD and their concussion history. Athletes were divided into two groups, those with ADHD (n=71; 6.8%) and control subjects (n=966). Chi-Square tests were conducted to compare the number of prior concussions in students with and without ADHD.

Results
In the total sample, boys were more likely to report a prior history of concussion than girls [χ2(1) =10.81, p=.001; OR=1.92; 95% CI=1.30-2.85]. The frequency of prior concussion in children with ADHD (23.9%) was twice the frequency of prior concussion among children without ADHD (11.4%) [χ2(1)=9.70, p=.002; OR=2.45; 95% CI=1.37-4.38]. Approximately one in four boys with ADHD (24.5%) and one in five girls with ADHD (22.2%) reported having sustained one or more prior concussions.

Conclusion
ADHD is associated with a greater prevalence of prior concussion in middle school children. Further research is needed to understand the risk of sustaining concussion for young athletes with ADHD, as well as short- and long-term outcomes of concussion among young athletes with ADHD.
Exploring Athletic Trainers' Self-Confidence for Interpreting Results from Concussion Assessments
Authors: D’Amico N R , Covassin T , Murray N , Schatz P , Elbin R J 
Published: July 2019

Abstract

Purpose
To explore athletic trainers' self-confidence for interpreting results from concussion assessments.

Methods
An online survey was administered via the National Athletic Trainers’ Association (NATA) membership listserv to a cross-sectional sample of 10,000 certified athletic trainers (ATCs) employed in high school and collegiate settings. The survey included: 1) ATC demographics (i.e., age, sex, years of experience); 2) ATC concussion management practices (i.e., previous concussion training, continuing education received on concussion, concussion assessments administered); and 3) a 4-point Likert scale (1=no confidence, 4=high confidence) assessing ATC self-confidence for interpreting results from concussion assessments. A total of 725 ATCs completed the survey yielding a response rate of 7.25%; 114 were excluded for missing data and 611 ATCs were included in final analyses. Sample demographics, ATC concussion management practices, and ATC self-confidence scores were examined with demographic statistics (i.e., means, standard deviations, frequencies, percentages) for 16 commonly used concussion assessments.

Results
The sample of ATCs (mean age 38.97±14.89 years) was predominately female (59.2%) and reported an average of 10.08±7.58 years of clinical experience. Clinical examinations (63.2%) and symptom scales (61.4%) were among the most frequent assessments with high ATC self-confidence for interpretation. Vestibular/oculomotor measures (27.2%) and computerized neurocognitive testing (26.2%) were among the most frequent assessments with low ATC self-confidence for interpretation.

Conclusion
Low ATC self-confidence scores for interpreting results from vestibular/oculomotor measures and computerized neurocognitive testing highlight the importance of incorporating a multi-disciplinary team approach and including sport neuropsychologists for the proper management of concussion.
Initial Average Symptom Severity is a Better Predictor of Recovery following Concussion than Total Symptom Burden
Authors: Kowalczyk C L , Holland C L , Collins M W , Kontos A P 
Published: July 2019

Abstract

Purpose
Symptom reports such as the Post-concussion Symptom Scale (PCSS) are common assessments following concussion. Patients with high symptom burden following a concussion take longer to recover. However, two patients could have a symptom burden of 30, which is high, but one patient has endorsed only 6 items for an average severity of 5; whereas, another patient has endorsed 15 items for an average severity of 2. The purpose of this study was to compare the association of different symptom outcomes (i.e., average symptom severity, total symptom severity [i.e., symptom burden] and total number of symptoms) on recovery time.

Methods
Participants included 109 (46-M/64-F) concussed patients aged 13–21 years (15.0±1.7) from a specialty clinic. Participants completed the PCSS and total symptom and average symptom severity scores were then calculated. Recovery time (i.e., date of injury to full medical clearance) was recorded. Pearson product-moment correlations and multiple regression (MR) were used to analyze the data.

Results
The results from the Pearson product-moment correlations indicated that all of the symptom outcomes were correlated. Only the average symptom severity score was correlated (r=.23, p<.05) with recovery time. Results from the MR for recovery time indicated that average symptom severity was associated with a longer recovery time (Beta=.40, t=2.2, p=.03).

Conclusion
Findings indicate that average symptom severity was the best predictors of recovery time, which is in contrast to the literature, and highlights the importance for clinicians to consider average symptom severity in prognosis following concussion.
The Relation Between Cognitive Performance and Symptom Factors Following Concussion
Authors: Whitley E , Gerkin R , Kontos A , Quintana C , Nalepa B , Pardini J 
Published: July 2019

Abstract

Purpose
The purpose of this study was to explore if symptom factors are related to cognitive outcomes. Prior studies have examined the relationship of individual symptoms to cognition. However, the relation between empirically-derived symptom factors and cognitive outcomes has yet to be explored.

Methods
Data were extracted via retrospective chart review of 691 patients (aged 10–24, mean: 14.99±2.63). Participants completed ImPACT and the PCSS within 14 days of injury (mean: 9.27±3.37). Predictors were PCSS factor scores of Cognitive-Fatigue-Migraine (CFM), Affective (AFF), Somatic (SOM), and Sleep (SLP) (Kontos et al., 2012). Outcomes examined were ImPACT composite scores. Univariate analyses were performed and values with p < 0.10 were entered into stepwise linear regression (LR) models. Retained predictors in each LR model had p values <.05.

Results
Verbal memory was predicted by CFM, SOM, age, and gender. Visual memory was predicted by CFM and SOM. Visual motor speed was predicted by age, gender, CFM, SOM, and AFF. Reaction time was best predicted by SOM, CFM, and age. The variance explained was fairly small (0.08 to 0.21). SLP was not a significant predictor in any LR.

Conclusion
CFM and SOM factors were most predictive of lower cognitive performance, similar to prior studies linking dizziness to longer recovery and post-traumatic migraine to worse cognitive performance. These findings underscore the clinical importance of diverse symptom assessment and injury education. Higher CFM and SOM scores may also serve as proxy for injury severity, which we would expect to be associated with worse cognitive performance.
Reliability and Consistency of the Vestibular/Ocular Motor Screening (VOMS) Assessment Near Point of Convergence (NPC) Trials
Authors: Ernst N , Sufrinko A , Collins M , Kontos A 
Published: July 2019

Abstract

Purpose
To examine the reliability of near point of convergence (NPC) across three trials and determine if one trial of NPC is adequate to identify receded NPC post-concussion.

Methods
Participants included 263 concussed patients (64.3% male; age=16.92±3.49 years) evaluated within 21 days of injury. NPC was measured in centimeters from the tip of the nose using a fixation stick and a Gulick anthropometric tape measure. A two-way, mixed effect, absolute agreement intraclass correlation coefficient (ICC 3,1) was conducted to evaluate reliability across the three trials. A chi-square analysis examined consistency of NPC classification (normal/abnormal) on the initial trial compared to average across three trials.

Results
Reliability of the three trials was high (.91 [95%CI, .89–.93]). Agreement between Trial 1 classification and classification based on average of all three trials was high (96.2%). Of the 10 participants who were classified differently for Trial 1 compared to average trials, 8 had borderline (e.g., 4–6 cm) measurements on the first trial.

Conclusion
NPC measurement across trials is reliable for the overall sample, but those who fell well below (i.e. 0–1cm) or well above (>8cm) clinical cutoffs on the first trial were almost always below or above respective cutoffs on the average convergence (>99%). Results suggest it is important to measure NPC across multiple trials for patients with initial borderline measurement.
Preliminary Examinations of Concussion in Older Adults
Authors: Combs J , Puskar A , Blaney N , Collins M , Kontos A 
Published: July 2019

Abstract

Purpose
This study sought to investigate whether concussion in older adults improves through evaluating their performance on the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and Vestibular/Ocular-Motor Screen (VOMS) across visits and to describe and better characterize concussion in this at-risk population.

Methods
We conducted a retrospective review of medical records for 69 older adult patients (40 females, 29 males) that presented to a concussion specialty clinic. Participants averaged 64.71 (SD=4.1) years in age and presented within 6-998 days of injury (SD=170.9). Demographics and clinical data were recorded at intake through last appointment. Descriptive analysis, including frequencies, means, and standard deviations were performed as well as paired T-test to compare mean scores for first and last visit. Statistical significance was determined by two-sided p-values <.05.

Results
Twenty out of 69 participants (29%) reported a previous concussion. Concussion symptom severity scores at participants’ first clinic visit averaged 56.19 (SD=26.56) compare with 39.51 (SD=25.53) at their final clinic visit. When comparing ImPACT data, all scores improved comparatively from Visit 1 to Last Visit (P values =0.000-0.014); all VOMS total scores improved as well (P =0.00-0.047). The most frequent primary profile among participants was Vestibular (31.9%).

Conclusion
Older adults diagnosed with concussion showed improvement on ImPACT scores and their symptom severity scores decreased. The most frequent primary concussion profile at initial visit was Vestibular. Further research with this at-risk population is needed.
Variability in ImPACT Baseline Scores in Adolescent Athletes
Authors: Bennett R , Datoc A , Stebbins L , Lashley L , Posey A 
Published: July 2019

Abstract

Purpose
The purpose of this study was to observe the test-retest-reliability of adolescent athlete Baseline ImPACT scores over a one and two-year interval.

Methods
Participants were selected from an archival de-identified sports medicine ImPACT database in Florida. The sample (N=4,044) consisted of primarily male (62.2%), adolescent athletes aged (Mage= 15.45, SD=1.291). Athletes were included in the study if they completed an initial and follow-up baseline ImPACT between 2016 and 2019, and if they had no history of concussion. One-Way ANOVA was conducted to determine the relationship between overall mean composite and total symptom scores between baseline tests.

Results
One-Way ANOVA revealed Verbal Memory (F[2,4041])=16.231, p<.001), Visual Memory (F[2,4041])=23.528, p<.001), and Visual Motor (F[2,4041)=46.111, p<.001) composite scores significantly differed over time. While these results yielded statistical significance over time, further descriptive statistics showed that the mean differences for these composite scores did not fall outside of the ImPACT Reliable Change Index (RCI) criteria.

Conclusion
Assuming no significant physical or cognitive changes between baseline administrations, ImPACT composite and total symptom scores are expected to be consistent over time. Results indicate that ImPACT composite and total symptom scores are reliable in an adolescent sample across one and two-year time periods. Previous literature regarding test-retest reliability of composite and total symptom scores on ImPACT in youth and adolescent athletes has been inconsistent, which has caused researchers and clinicians to question the clinical utility of this assessment. Future research is needed to highlight the utilization of clinical judgement and clarify the psychometric properties of this measure.
Relationships between Head Impacts, Competitive Aggression, and Risk-taking Behavior in Collegiate Ice Hockey Players
Authors: DiFabio M S , Buckley T A 
Published: July 2019

Abstract

Purpose
To examine relationships between head impact kinematics sustained over a season and competitive aggression and self-reported risk-taking behavior in collegiate club ice-hockey athletes.

Methods
Twenty male ice-hockey players (19.9±1.2 y.o, 1.8±0.06 m, 78.5±5.7 kg) completed the Competitive Anger and Aggression Scale (CAAS, Range:0-84) and the Brief Sensation Seeking Scale (BSSS, Range:8-40) during the preseason as measures of competitive aggression and risk-taking behavior with higher/lower reflecting higher/lower aggression and risk taking. Penalty minutes (PM) and games played (GP) were taken from official game records. Head impact kinematics (number of impacts, linear mean, peak, cumulative acceleration) were recorded by tri-axial accelerometers worn during games/practices. Spearman correlation was performed to examine relationships between variables.

Results
The mean number of impacts was 76.6±54.9 (range: 6–171); mean and cumulative acceleration were 36.3±4.2g (range:27.8–42.2g) and 2829.4±2024.9g (range:198.4–6527.2g), respectively. Neither CAAS (mean: 48.7±10.9, range: 24–64) nor BSSS scores (mean: 25.3±4.4, range:15–32) were significantly related to impact kinematics. GP was significantly correlated with number of impacts (r=.63, p=.003) and cumulative linear acceleration (r=.61, p=.004). PM was significantly correlated with number of impacts (r=.52, p=.20) and cumulative linear acceleration (r=.55, p=.13).

Conclusion
There were no relationships between the head impact kinematics and self-reported aggressiveness or risk taking behavior, but more PM was strongly related to higher head impact loads. Considering PM may be useful in aiding to identify athletes who may sustain higher head impact loads, however, self-reports of behavior may not be.
Testing the Hybrid Battery Approach to Evaluating Sports-Related Concussion in the National Hockey League: A Factor Analytic Study
Authors: Echemendia R J , Bruce J M , Thelen J , Hutchison M , Comper P , Meeuwisse W 
Published: July 2019

Abstract

Purpose
Traditional “paper and pencil” neuropsychological tests and computerized test batteries have been employed in the assessment of sports-related concussion (SRC). Each type of test has inherent strengths and weaknesses. The NHL has constructed a “hybrid” battery of tests that uses both traditional and computerized measures in the evaluation of its players suspected of SRC. The purpose of this paper is to use factor analytic techniques to examine the relationships among the measures that comprise this battery.

Methods
Post-injury neuropsychological test data using the hybrid battery were obtained from 343 NHL players following their first concussion while playing in the league. ImPACT was used as the computer test battery. The traditional battery included: Hopkins Verbal Learning Test, Brief Visuospatial Memory Test, Color Trails, PSU Cancellation, Symbol Digits Modalities Test (including incidental memory), and Verbal Fluency.

Results
Five factors were extracted explaining 64.55% of the variance. The factor labels and the measures principally loading on each factor were as follows: Factor 1, Verbal Learning and Memory (HVLT Total and Delayed Recall); Factor 2, Processing Speed (Color Trails A/B, PSU Cancellation, and SDMT-Total); Factor 3, Visual Memory (BVMT- Total and Delayed); Factor 4, Cued Memory (ImPACT-Visual and Verbal Memory Composites); and Factor 5, Reaction Time (ImPACT Reaction Time and Visual Motor Speed composites).

Conclusion
These data underscore the unique contributions of traditional and ImPACT neuropsychological measures to the evaluation SRC in a sample of professional hockey players. It appears that both approaches measure different aspects of cognitive functioning. The next logical step is to use these data in evaluating the diagnostic utility of these measures as part of a combined battery.
The Influence of Hormonal Contraceptives on Baseline ImPACT Performance
Authors: Carrington H W , Broshek D K , Erdman N K , Thompson X D , Walton S R , Resch J E 
Published: July 2019

Abstract

Purpose
Our study examined the influence of hormonal contraceptives (HC) on pre-injury (baseline) ImPACT performance in female collegiate athletes.

Methods
Participants in our cross-sectional study consisted of 304 NCAA Division I female athletes who self-reported taking (HC+ [n=154]) or not taking (HC- [n=154]) HC. HC+ participants were matched to HC- participants for height, weight, sport, and position. HC+ participants had an average age of 19.0±1.33 years, height of 170.5–8.70 cm, and mass of 64.2–10.58 kg. HC- participants had an average age of 19.0±1.24 years, height of 170.3–9.19 cm, and mass of 64.2–9.75 kg. Participants completed ImPACT as part of their preseason baseline assessment. Only participants with valid ImPACT assessments were included in our analyses. Chi-squared (χ2) tests were performed to compare groups in terms of medical history variables. Independent t-tests were used to compare groups in terms of demographic variables, self-reported hours of sleep, and ImPACT (Verbal and Visual Memory, Visual Motor Speed [VMS], Reaction Time [RT], and Total Symptom Severity [TSS]) outcome scores. Analyses were performed with α=0.05.

Results
No differences were observed between groups for demographic variables, hours of sleep, or medical history variables (p<0.05). For VMS, the HC- group (42.9+5.63) scored significantly worse (t[304]=2.17, p=0.03; d=0.25; 95% CI [0.1, 2.7]) than the HC+ group (44.3+5.67). For RT, the HC- group (0.55+0.06) performed significantly slower (t[304]=-2.02, p=0.05; d=0.23; 95% CI [-0.03, -0.0003]) than the HC+ group (0.54+0.05).

Conclusion
Our results suggest HCs may influence ImPACT performance in female collegiate athletes. Clinicians must consider the role of HCs when interpreting ImPACT outcome scores.
PyMethylProcess—convenient high-throughput preprocessing workflow for DNA methylation data
Authors: Levy Joshua J , Titus Alexander J , Salas Lucas A , Christensen Brock C 
Published: July 2019

Abstract

Summary
Performing highly parallelized preprocessing of methylation array data using Python can accelerate data preparation for downstream methylation analyses, including large scale production-ready machine learning pipelines. We present a highly reproducible, scalable pipeline (PyMethylProcess) that can be quickly set-up and deployed through Docker and PIP.

Availability and implementation
Project Home Page: https://github.com/Christensen-Lab-Dartmouth/PyMethylProcess. Available on PyPI (pymethylprocess), Docker (joshualevy44/pymethylprocess).

Supplementary information
Supplementary data are available at Bioinformatics online.
Gaussian mixture copulas for high-dimensional clustering and dependency-based subtyping
Authors: Kasa Siva Rajesh , Bhattacharya Sakyajit , Rajan Vaibhav 
Published: July 2019

Abstract

Motivation
The identification of sub-populations of patients with similar characteristics, called patient subtyping, is important for realizing the goals of precision medicine. Accurate subtyping is crucial for tailoring therapeutic strategies that can potentially lead to reduced mortality and morbidity. Model-based clustering, such as Gaussian mixture models, provides a principled and interpretable methodology that is widely used to identify subtypes. However, they impose identical marginal distributions on each variable; such assumptions restrict their modeling flexibility and deteriorates clustering performance.

Results
In this paper, we use the statistical framework of copulas to decouple the modeling of marginals from the dependencies between them. Current copula-based methods cannot scale to high dimensions due to challenges in parameter inference. We develop HD-GMCM, that addresses these challenges and, to our knowledge, is the first copula-based clustering method that can fit high-dimensional data. Our experiments on real high-dimensional gene-expression and clinical datasets show that HD-GMCM outperforms state-of-the-art model-based clustering methods, by virtue of modeling non-Gaussian data and being robust to outliers through the use of Gaussian mixture copulas. We present a case study on lung cancer data from TCGA. Clusters obtained from HD-GMCM can be interpreted based on the dependencies they model, that offers a new way of characterizing subtypes. Empirically, such modeling not only uncovers latent structure that leads to better clustering but also meaningful clinical subtypes in terms of survival rates of patients.

Availability and implementation
An implementation of HD-GMCM in R is available at: https://bitbucket.org/cdal/hdgmcm/.

Supplementary information
Supplementary data are available at Bioinformatics online.