Repetitive head impacts in a collegiate football season: Exposure and effects

2021 ◽  
pp. 174795412110272
Author(s):  
Laura D Wilson ◽  
Rachel A Hildebrand ◽  
Trang Le ◽  
Brett A McKinney
Keyword(s):  
Reaction Time ◽  
American Football ◽  
Division I ◽  
Football Players ◽  
Short Term ◽  
Head Impacts ◽  
Repetitive Head Impacts ◽  
The Past ◽  
Acute Increase ◽  
Collegiate Football

This study describes exposure to repetitive head impacts (RHI) by player position and activity during a collegiate football season, and investigates the relationship between RHI and acute (i.e., daily and weekly) and short-term (i.e., pre- to post-season) changes in balance, reaction time, symptoms, and cognition. We recorded RHI exposure in twenty Division I collegiate American football players during a single season using the Riddell InSite system. Participants sustained 4,586 impacts (4.20% high impact, i.e., >63 g; 95.79% low impact, i.e., 20–63 g). Greatest exposure to RHI was observed in running backs and defensive ends during games, and tight ends and defensive ends during practices. Running plays and team drills placed players at greatest risk for exposure during practice. Cumulative RHI exposure across the season was associated with short-term declines in reaction time (p = 0.045), but not balance or cognition. Acute decline in balance was associated with the number of impacts sustained in the past week (p < 0.05), but not the past 24 hours (p > 0.05). Acute increase in total symptom score was also associated with the number of impacts sustained in the past week (p < 0.01), but not the past 24 hours (p > 0.05). Reaction time did not decline based on impact exposure in the past 24 hours or week. This study identifies activities and positions that may put players at risk for RHI exposure, and demonstrates that RHI sustained during the course of typical American football play by non-concussed individuals may result in small changes in balance, reaction time, and symptoms, but not cognition.

Association Between Antemortem FLAIR White Matter Hyperintensities and Neuropathology in Brain Donors Exposed to Repetitive Head Impacts

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000013012
Author(s):  
Madeline Uretsky ◽  
Sylvain Bouix ◽  
Ronald J. Killiany ◽  
Yorghos Tripodis ◽  
Brett Martin ◽  
...  
Keyword(s):  
White Matter ◽  
White Matter Hyperintensities ◽  
Microvascular Disease ◽  
Head Impact ◽  
American Football ◽  
Football Players ◽  
Head Impacts ◽  
Repetitive Head Impacts ◽  
Pathological Correlation ◽  
Daily Function

Background and Objectives:Late neuropathologies of repetitive head impacts from contact sports can include chronic traumatic encephalopathy (CTE) and white matter degeneration. White matter hyperintensities (WMH) on fluid attenuated inversion recovery (FLAIR) MRI scans are often viewed as microvascular disease from vascular risk, but might have unique underlying pathologies and risk factors in the setting of repetitive head impacts. We investigated the neuropathological correlates of antemortem WMH in brain donors exposed to repetitive head impacts. The association between WMH, and repetitive head impact exposure and informant-reported cognitive and daily function were tested.Methods:This imaging-pathological correlation study included symptomatic deceased men exposed to repetitive head impacts. Donors had antemortem FLAIR scans from medical records and were without evidence of CNS neoplasm, large vessel infarcts, hemorrhage, and/or encephalomalacia. WMH were quantified using log-transformed values for total lesion volume (TLV), calculated using the lesion prediction algorithm from the Lesion Segmentation Toolbox. Neuropathological assessments included semi-quantitative ratings of white matter rarefaction, cerebrovascular disease, p-tau severity (CTE stage, dorsolateral frontal cortex), and Aβ. Among football players, years of play was a proxy for repetitive head impact exposure. Retrospective informant-reported cognitive and daily function were assessed using the Cognitive Difficulties Scale (CDS) and Functional Activities Questionnaire (FAQ). Regression models controlled for demographics, diabetes, hypertension, and MRI resolution. Statistical significance was defined as p<0.05.Results:The sample included 75 donors: 67 football players and 8 non-football contact sport athletes and/or military veterans. Dementia was the most common MRI indication (64%). Fifty-three (70.7%) had CTE at autopsy. Log-TLV was associated with white matter rarefaction (OR=2.32, 95% CI=1.03,5.24, p=0.04), arteriolosclerosis (OR=2.38, 95% CI=1.02,5.52, p=0.04), CTE stage (OR=2.58, 95% CI=1.17,5.71, p=0.02), and dorsolateral frontal p-tau severity (OR=3.03, 95% CI=1.32,6.97, p=0.01). There was no association with Aβ. More years of football play was associated with log-TLV (b=0.04, 95% CI=0.01,0.06, p=0.01). Greater log-TLV correlated with higher FAQ (unstandardized beta=4.94, 95% CI=0.42,8.57, p=0.03) and CDS scores (unstandardized beta=15.35, 95% CI=-0.27,30.97, p=0.05).Discussion:WMH might capture long-term white matter pathologies from repetitive head impacts, including those from white matter rarefaction and p-tau, in addition to microvascular disease. Prospective imaging-pathological correlation studies are needed.Classification of Evidence:This study provides Class IV evidence of associations between FLAIR white matter hyperintensities, and neuropathological changes (white matter rarefaction, arteriolosclerosis, p-tau accumulation), years of American football play, and reported cognitive symptoms in symptomatic brain donors exposed to repetitive head impacts.

Examination of Body Mass Changes Among Division I Collegiate Football Players With Sickle Cell Trait

2021 ◽  
pp. 1-6
Author(s):  
Rebecca M. Hirschhorn ◽  
Jessica L. Phillips Gilbert ◽  
Danielle A. Cadet ◽  
Tenley E. Murphy ◽  
Clinton Haggard ◽  
...  
Keyword(s):  
Body Mass ◽  
Sickle Cell ◽  
Student Athletes ◽  
Sickle Cell Trait ◽  
American Football ◽  
Division I ◽  
Football Players ◽  
Significant Difference ◽  
Body Mass Changes ◽  
Collegiate Football

American football athletes are frequently hypohydrated before and during activity. Hypohydration increases the risk of exertional sickling in student-athletes with sickle cell trait (SCT). The authors examined weight charts from the 2010/2011 to 2018/2019 seasons at one Division I institution to determine if differences in percentage body mass losses (%BML) exist between those with and without SCT. Seventeen student-athletes with SCT and 17 matched-controls were included. A Bonferroni correction was applied to account for multiple comparisons (0.05/8), resulting in p < .006 considered significant. There was a significant difference for %BML between groups (SCT: 0.84 ± 0.65% vs. control: 1.21 ± 0.71%; p = .002) but not for the number of days %BML exceeded 2% (SCT: 0 ± 1 vs. control: 1 ± 1; p = .016). Implementation of proper hydration strategies minimized %BML in athletes with SCT, decreasing the risk of hypohydration and exertional sickling. The same strategies ensured all players remained below threshold to optimize performance and reduce heat illness risk.

scholarly journals Positional Differences in Pre-Season Scrimmage Performance of Division I Collegiate Football Players

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 769
Author(s):  
Kate S. Early ◽  
Nathan P. Lemoine ◽  
Annie Simoneaux ◽  
Shelly Mullenix ◽  
Jack Marucci ◽  
...  
Keyword(s):  
Activity Level ◽  
Burst Duration ◽  
American Football ◽  
Division I ◽  
Football Players ◽  
Activity Levels ◽  
Performance Variables ◽  
Specific Analysis ◽  
Skill Performance ◽  
Collegiate Football

This study aimed to describe the physical demands of American football players using novel performance analysis techniques. Heart rate (HR) and accelerometer-based activity levels were observed across two pre-season scrimmages in 23 Division I collegiate football players (age: 19 ± 1 y, height: 1.90 ± 0.06 m, weight: 116.2 ± 19.4 kg). Data were analyzed using a MATLAB program and inter-rater reproducibility assessed using inter-class correlations (ICC). Players were analyzed by side (offense/defense) and position (skill/non-skill). Performance variables assessed in bursts of activity included burst duration, HRmean and HRmax (bpm), and mean activity (vector magnitude units [vmu]). Exercise intensity was categorized as time spent in % HRmax in 5% increments. The burst duration (8.1±3.9 min, ICC = 0.72), HRmean (157 ± 12 bpm, ICC = 0.96) and mean activity (0.30 ± 0.05 vmu, ICC = 0.86) were reproducible. HRmean (p = 0.05) and HRmax (p = 0.001) were greater on defense. Offense spent more time at 65–70% HRmax (p = 0.01), 70–75% HRmax (p = 0.02) while defense spent more time 90–95% HRmax and ≥95% HRmax (p = 0.03). HRmean (p = 0.70) and HRpeak (p = 0.80) were not different between positions across both sides. Skilled players demonstrated greater mean activity (p = 0.02). The sport-specific analysis described HR and activity level in a reproducible manner. Automated methods of assessing HR may be useful in training and game time performance but ultimately provides support to coaching decision making.

scholarly journals Pilot Evaluation of a Novel Clinical Test of Reaction Time in National Collegiate Athletic Association Division I Football Players

2010 ◽  
Vol 45 (4) ◽  
pp. 327-332 ◽  
Author(s):  
James T. Eckner ◽  
Jeffrey S. Kutcher ◽  
James K. Richardson
Keyword(s):  
Reaction Time ◽  
National Collegiate Athletic Association ◽  
Neuropsychological Test ◽  
Cross Sectional Study ◽  
Division I ◽  
Football Players ◽  
Clinical Test ◽  
Clinical Tool ◽  
Cross Sectional ◽  
Collegiate Football

Abstract Context: Evidence suggests that concussion prolongs reaction time (RT). We have developed a simple, reliable clinical tool for measuring reaction time that may be of value in the assessment of concussion in athletes. Objective: To compare baseline values of clinical RT (RTclin) obtained using the new clinical reaction time apparatus with computerized RT (RTcomp) obtained using a validated computerized neuropsychological test battery. Design: Cross-sectional study. Setting: Data were collected during a National Collegiate Athletic Association Division I collegiate football team's preparticipation physical examination session. Patients or Other Participants: Ninety-four Division I collegiate football players. Main Outcome Measure(s): The RTclin was measured using a 1.3-m measuring stick embedded in a weighted rubber disk that was released and caught as quickly as possible. The RTcomp was measured using the simple RT component of CogState Sport. Results: For the 68 athletes whose CogState Sport tests passed the program's integrity check, RTclin and RTcomp were correlated (r  =  0.445, P &lt; .001). Overall, mean RTclin was shorter and less variable than mean RTcomp (203 ± 20 milliseconds versus 268 ± 44 milliseconds; P &lt; .001). When RTclin and RTcomp were compared between those athletes with (n  =  68) and those without (n  =  26) valid CogState Sport test sessions, mean RTclin was similar (202 ± 19 milliseconds versus 207 ± 23 milliseconds; P  =  .390), but mean RTcomp was different (258 ± 35 milliseconds versus 290 ± 55 milliseconds; P  =  .009). Conclusions: The RTclin was positively correlated with RTcomp and yielded more consistent reaction time values during baseline testing. Given that RTclin is easy to measure using simple, inexpensive equipment, further prospective study is warranted to determine its clinical utility in the assessment of concussion in athletes.

scholarly journals Effects of Protective American Football Headgear on Peripheral Vision Reaction Time and Visual Target Detection in Division I NCAA Football Players

Sports ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 213
Author(s):  
Rachel A. Miller ◽  
Rebecca R. Rogers ◽  
Tyler D. Williams ◽  
Mallory R. Marshall ◽  
Justin R. Moody ◽  
...  
Keyword(s):  
Reaction Time ◽  
Target Detection ◽  
Peripheral Vision ◽  
Visual Target ◽  
Reaction Times ◽  
American Football ◽  
Division I ◽  
Football Players ◽  
Time Test ◽  
Reaction Time Test

The purpose of this study was to examine the effects of protective football headgear on peripheral vision reaction time and visual target detection. Twenty-five Division I NCAA football players (age = 20.5 yrs ± 0.9, height = 185.9 cm ± 6.8, body mass = 99.2 kg ± 19.2, BMI = 29.6 ± 4.5) participated. In a crossover counterbalanced study design, subjects participated in one visit with three conditions: Baseline (BL) without headgear, helmet only (HO), helmet with an eye shield (HE). Subjects completed a 1-min peripheral vision reaction time test for each condition separated by 3-min recovery periods. Tests were administered using a 64 light Dynavision D2 Visuomotor board. Target detection (total hit score) was higher during BL than HO (p < 0.001) and HE (p < 0.001). Average (p < 0.001), peak (p < 0.001), minimum (p < 0.001), and median (p < 0.001) peripheral reaction times were faster during BL than HO and HE. No significant differences were observed for any measures between HO and HE conditions (p > 0.05). Findings indicate that protective football headgear impaired reaction time to peripheral visual stimuli. The addition of an eye shield to the helmet had a small non-significant effect on reaction time and target detection. These results may hold important implications in helmet design and player safety.

Chronic Traumatic Encephalopathy: Advocacy and Communicating with the Public

2020 ◽  
Vol 40 (04) ◽  
pp. 461-468
Author(s):  
Madeline Uretsky ◽  
Christopher J. Nowinski
Keyword(s):  
Chronic Traumatic Encephalopathy ◽  
American Football ◽  
Football Players ◽  
Advocacy Groups ◽  
Contact Sport ◽  
Head Impacts ◽  
The Public ◽  
The Past ◽  
Raising Awareness ◽  
Sports Concussions

AbstractOver the past 40 years, advocacy groups have been instrumental in raising awareness for neurodegenerative diseases such as Alzheimer's disease. More recently, advocates have emerged to educate about sports concussions and chronic traumatic encephalopathy (CTE), including the Concussion Legacy Foundation (CLF). CTE is a neurodegenerative disease caused in part by repetitive head impacts (RHI). While the majority of CTE research has focused on studying former American football players, CTE has also been found in military personnel, victims of domestic violence, and contact sport athletes from high school to professional levels of play. Advocates' many goals include creating a culture of brain donation and modifying youth contact sports to decrease RHI. Here, we provide the first review of CTE advocacy, summarize the accomplishments of the CLF, and consider the connections between CTE advocacy, research, and legislation over the last decade.

scholarly journals Age at First Exposure to Repetitive Head Impacts Is Associated with Smaller Thalamic Volumes in Former Professional American Football Players

2018 ◽  
Vol 35 (2) ◽  
pp. 278-285 ◽  
Author(s):  
Vivian Schultz ◽  
Robert A. Stern ◽  
Yorghos Tripodis ◽  
Julie Stamm ◽  
Pawel Wrobel ◽  
...  
Keyword(s):  
American Football ◽  
Football Players ◽  
Head Impacts ◽  
Repetitive Head Impacts

History of Chronic Traumatic Encephalopathy

2020 ◽  
Vol 40 (04) ◽  
pp. 353-358
Author(s):  
Robert C. Cantu ◽  
Charles Bernick
Keyword(s):  
Chronic Traumatic Encephalopathy ◽  
Neurological Impairment ◽  
American Football ◽  
Football Players ◽  
Long Term Effects ◽  
Public Attention ◽  
Head Impacts ◽  
Repetitive Head Impacts ◽  
History Of ◽  
Initial Description

AbstractThe long-term effects of repetitive head impacts have been recognized for close to a century. What is now referred to as chronic traumatic encephalopathy (CTE) was first described by Martland in 1928 in a series of boxers. Over the years, several important articles were published, including Critchley's 1957 report where he introduced the term “chronic traumatic encephalopathy,” Robert's study in 1969 which provided evidence of the prevalence of neurological impairment in retired fighters, and Corsellis' initial description of the pathology of CTE. However, what brought public attention to the issue of CTE in sports were the postmortem findings of CTE pathology in professional American football players, initially reported by Omalu and subsequently in a large series by McKee. There is now standardization of pathological criteria for CTE and recognition that it can be seen across all activities that involve repetitive head impacts.

scholarly journals Protective Football Headgear and Peripheral Visuomotor Ability in NCAA Football Athletes: The Role of Facemasks and Visors

2021 ◽  
Vol 6 (2) ◽  
pp. 34
Author(s):  
Christopher G. Ballmann ◽  
Anna C. Covington ◽  
Rachel A. Miller ◽  
Rebecca R. Rogers
Keyword(s):  
Reaction Time ◽  
Division I ◽  
Football Players ◽  
Visual Areas ◽  
Peripheral Areas ◽  
Player Performance ◽  
Collegiate Football ◽  
Visuomotor Performance

The purpose of this investigation was to determine the effects of varying facemask reinforcement and visor tint on peripheral visuomotor abilities in collegiate football players. Division I NCAA football players (n = 14) completed two peripheral visuomotor experiments: (1) Varying facemask reinforcement, (2) Varying visor tinting. In experiment 1, participants were tested under the following conditions: baseline (no helmet; BL), helmet + light (HL), helmet + medium (HM), helmet + heavy (HH), and helmet + extra heavy (HXH) reinforced facemasks. In experiment 2, participants were tested under the following conditions: baseline (no helmet; BL), helmet only (HO), helmet + clear (HCV), helmet + smoke-tinted (HSV), and helmet + mirror-tinted (HMV) visors. For each condition, a 60 s peripheral visuomotor test was completed on a Dynavision D2 visuomotor board. For experiment 1, the BL peripheral reaction time (PRT) was faster than all facemask conditions (p < 0.05). Furthermore, PRT was impaired with the HXH compared to HL (p < 0.001), HM (p < 0.001), and HH (p = 0.001). Both HH and HXH resulted in the potentiation of PRT impairments in the outermost and inferior peripheral visual areas (p < 0.05). In experiment 2, BL PRT was faster than all helmeted conditions (p < 0.05). Additionally, PRT was slower in HSV (p = 0.013) and HMV (p < 0.001) conditions compared to HO. HMV resulted in slower PRT in all peripheral areas (p < 0.05) while PRT was impaired only in outer areas for HSV (p < 0.05). Wearing protective football headgear impairs peripheral visuomotor ability. Lighter reinforced facemasks and clear visors do not appear to exacerbate impairment. However, heavier reinforced facemasks and tinted visors further decrease visuomotor performance in outer and inferior visual areas, indicating a potential need for considerations of on-field player performance and safety.

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