Return to play after head injury in adolescent sports: evaluating football versus other sports.

OBJECTIVE: Increased adolescent sports participation has raised concerns about higher rates of concussions, a prevalent injury among young athletes with potential long-term effects. Discrepancies in concussion recovery and management protocols across various sports underscore a critical issue in youth athletics. This study aimed to examine the relationship between sport type and the number of games missed following a concussion to inform targeted management strategies. METHODS: Data from 7445 postinjury ImPACT tests for athletes aged 12-22 years, collected from 2009 to 2019, were analyzed across different sports: baseball, basketball, cheerleading, football, ice hockey, lacrosse, soccer, softball, swimming, track and field, volleyball, and wrestling. The number of days and normalized missed games (NMG), a metric accounting for the different number of games in a season for different sports, were used to evaluate the effect of concussions across different sports. ANOVA, t-tests, and linear regression analyses were performed to model the effect of sport type on games missed in a season while controlling for sex, age, concussion history, diagnosed learning disability (DLD), and attention-deficit/hyperactivity disorder (ADHD). RESULTS: Multivariable linear regression analysis demonstrated that football participation significantly increased NMG (ß 1.681, 95% CI 0.807-2.554; p < 0.001) and days missed (ß 1.637, 95% CI 1.044-2.231; p < 0.001) after head injury. Concussion diagnoses were also found to significantly increase NMG (ß 2.344, 95% CI 1.629-3.059; p < 0.001) and days missed (ß 1.560, 95% CI 1.074-2.045; p < 0.001), as well as history of prior concussion (NMG: ß 7.791, 95% CI 7.368-8.215; p < 0.001; days missed: ß 5.232, 95% CI 4.945-5.520; p < 0.001). In contrast, factors such as age, sex, DLD, ADHD, and concussions causing loss of consciousness did not significantly affect NMG or days missed. ANOVA with Tukey Honest Significant Difference indicated that compared with football, ice hockey (mean difference [MD] 5.4 days, p = 0.011) and track and field (MD 4.1 days, p = 0.006) were associated with significantly more days being missed after head injury. Conversely, basketball (MD -3.0, p < 0.001) and volleyball (MD -2.6, p = 0.005) were associated with fewer missed games. CONCLUSIONS: Adolescents playing football missed fewer days and games after concussion than other contact and noncontact sports, including ice hockey and track and field, raising questions about variations in return-to-play protocols and cultural attitudes within sports. Further research is needed to determine the factors affecting games missed across sport types in adolescent athletics and return-to-play protocols.

Effects of hours of sleep on ImPACT concussion testing: comparing baseline with postinjury scores.

OBJECTIVE: The influence of sleep on baseline and postconcussion neurocognitive performance prior to Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is poorly understood. Since ImPACT is widely used in youth sport to assess neurocognitive performance before and after head injury, it is important to delineate factors that affect testing performance. While some have reported correlations between fewer hours of sleep and lower scores on baseline tests, others have not observed any such associations. Therefore, the authors sought to compare the relationship between sleep and neurocognitive performance on ImPACT at both baseline and postinjury. METHODS: The authors queried a database of 25,815 ImPACT tests taken from 2009 to 2019 by athletes aged 12-22 years. There were 11,564 baseline concussion tests and 7446 postinjury concussion ImPACT tests used in the analysis. Linear regression was used to model the effect of sleep on baseline and postconcussion ImPACT scores adjusting for sex, age, learning disability, attention-deficit/hyperactivity disorder, number of prior concussions, number of games missed, and strenuous exercise before testing. RESULTS: Mean composite scores expectedly were all significantly lower in the post-head injury group compared with the baseline group. In the multivariable analysis, at baseline, hours of sleep significantly affected symptom scores (ß = -1.050, 95% CI -1.187 to -0.9138; p < 0.0001). In the postinjury multivariable analysis, verbal memory (ß = 0.4595, 95% CI 0.2080-0.7110; p = 0.0003), visual memory (ß = 0.3111, 95% CI 0.04463-0.5777; p = 0.0221), impulse control (ß = -0.2321, 95% CI -0.3581 to -0.1062; p = 0.0003), and symptom scores (ß = -0.9168, 95% CI -1.259 to -0.5750; p < 0.0001) were all affected by hours of sleep. CONCLUSIONS: Hours of sleep did not alter neurocognitive metrics at baseline but did have an impact on post-head injury metrics. These findings suggest that individuals may be able to compensate for lack of sleep at baseline but not immediately after concussion. Concussions may reduce cognitive reserve or detract from the brain's resources, making sleep even more important for proper neurocognitive functioning postconcussion. Future work will analyze the effects of sleep on postconcussion test performance.

The effect of age on baseline neurocognitive performance.

OBJECTIVE: Evaluate the independent effect of age on baseline neurocognitive performance. STUDY DESIGN: Baseline ImPACT scores from tests taken by 7454 athletes aged 12-22 from 2009 to 2019 were split into three age cohorts: 12-14 years (3244), 15-17 years (3732), and 18-22 years (477). Linear regression analyses were used to evaluate the effect of age on ImPACT composite scores while controlling for demographic differences, medication-use, and symptom burden. Significance values have been set at p < 0.05. RESULTS: Linear regression analyses demonstrated that increased age does not significantly affect symptom score (ß = 0.06, p = 0.54) but does improve impulse control (ß = -0.45, p < 0.0001), verbal memory (ß = 0.23, p = 0.03), visualmotor (ß = 0.77, p < 0.0001), and reaction time (ß = -0.008, p < 0.0001) scores.  However, age did not have an effect on visual memory scores (ß = -0.25, p = 0.07). CONCLUSIONS: Age was shown to be an independent modifier of impulse control, verbal memory, visual motor, and reaction time scores but not visual memory or symptom scores.  This underscores the previous literature showing developmental differences as age increases among the adolescent athlete population.  This data also indicates the need for repeat neurocognitive baseline testing every other year as baseline scoring is likely to change as athletes become older.

Baseline ImPACT Composite Scores in Student-Athletes With Attention-Deficit/Hyperactivity Disorder.

BACKGROUND: Athletes who are diagnosed with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of concussion compared to other athletes. Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a widely used concussion tool, but it relies on pre-injury baseline testing that can be affected by psychiatric conditions. This research aims to determine if there are differences in pre-injury testing composite scores in student-athletes with ADHD compared to those without ADHD diagnosis. METHODS: We obtained 11,563 pre-season ImPACT assessments of 7,454 student-athletes (ages: 12-22) from 2009 to 2019. After exclusions, there were 6,920 control and 276 ADHD subjects. Multivariable linear regression analyses compared the independent effect of ADHD on the six ImPACT composite score metrics with Bonferroni correction for multiple comparisons with a = 0.008. RESULTS: Univariate analyses indicated ADHD is associated with more symptoms as measured by the Post-Concussion Symptom Scale (PCSS) (ß = 2.67, 95% CI: 1.47-3.87, p < .0001) and worse Impulse Control scores (ß = 0.93, 95% CI: 0.33-1.53, p = .002). In multivariate analysis, this association was the same for symptom score (ß = 2.48, 95% CI: 1.22-3.74, p < .0001), but Impulse Control was not significantly different after multiple comparison adjustment (ß = 0.87, 95% CI: 0.22-1.15, p = .009). CONCLUSIONS: The ADHD subjects reported worse symptoms at baseline and had worse Impulse Control in univariate analysis, but not multivariate analysis. These results can further guide clinicians in concussion diagnosis and test interpretations for student-athletes with ADHD, considering the symptom burden at baseline.

Effects of repetitive head trauma on symptomatology of subsequent sport-related concussion.

OBJECTIVE: Adolescent participation in athletics continues to grow, leading to an increasing incidence of sports-related concussion (SRC). The current literature suggests that a greater number of prior concussions positively correlates with a greater number of total symptoms, but the specific concussion-related symptoms are not as well defined. The current study investigated the effects of prior recurrent head injury on the symptom profiles of student-athletes after another suspected concussion. METHODS: A multicenter database consisting of 25,815 Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) results was filtered for student-athletes aged 12-22 years old who competed in 21 different sports. Patients were separated into 2 cohorts: athletes reporting a single prior concussion (SRC1) and athletes reporting 2 or more prior concussions (SRC2+). Comparisons were assessed for differences in 22 symptoms and 4 symptom clusters at baseline, first postinjury test (PI1), and second postinjury test (PI2) by using univariate and multivariate analyses. RESULTS: No differences were seen between SRC1 (n = 2253) and SRC2+ (n = 976) at baseline. At PI1, the SRC2+ group (n = 286) had lower severity of headaches (p = 0.04) but increased nervousness (p = 0.042), irritability (p = 0.028), sadness (p = 0.028), visual problems (p = 0.04), and neuropsychiatric symptoms (p = 0.009) compared with SRC1 (n = 529). Multivariate analysis revealed decreased headache severity with increased prior concussion (ß = -0.27,95% CI -0.45 to -0.09, p = 0.003). Multivariate analysis at PI2 demonstrated the SRC2+ cohort (n = 130) had increased cognitive (ß = 1.22, 95% CI 0.27-2.18, p = 0.012), sleep (ß = 0.63, 95% CI 0.17-1.08, p = 0.007), and neuropsychiatric (ß = 0.67,95% CI 0.14-1.2,0.014) symptoms compared with SRC1 (n = 292). CONCLUSIONS: At longitudinal follow-up, patients with a history of recurrent concussions reported greater symptom burden in cognitive, sleep, and neuropsychiatric symptom clusters but not migraine symptoms. This is an important distinction because migraine symptoms are often more easily distinguishable to patients, parents, and physicians. Careful assessment of specific symptoms should be considered in patients with a history of recurrent head injury prior to return to play.

A multicenter, longitudinal survey of headaches and concussions among youth athletes in the United States from 2009 to 2019.

OBJECTIVE/ BACKGROUND: Chronic headaches and sports-related concussions are among the most common neurological morbidities in adolescents and young adults. Given that the two can overlap in presentation, studying the effects of one on another has proven difficult. In this longitudinal study, we sought to assess the relationship between chronic headaches and concussions, analyzing the role of historic concussions on chronic headaches, as well as that of premorbid headaches on future concussion incidence, severity, and recovery. METHODS: This multi-center, longitudinal cohort study followed 7,453 youth athletes who were administered demographic and clinical surveys as well as a total of 25,815 Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) assessments between 2009 and 2019. ImPACT was administered at baseline. Throughout the season concussions were examined by physicians and athletic trainers, followed by re-administration of ImPACT post-injury (PI), and at follow-up (FU), a median of 7 days post-concussion. Concussion incidence was calculated as the total number of concussions per patient years. Concussion severity and recovery were calculated as standardized deviations from baseline to PI and then FU in Symptom Score and the four neurocognitive composite ImPACT scores: Verbal Memory, Visual Memory, Processing Speed, and Reaction Time. Data were collected prospectively in a well-organized electronic format supervised by a national research-oriented organization with rigorous quality assurance. Analysis was preformed retrospectively. RESULTS: Of the eligible athletes, 1,147 reported chronic headaches (CH) at the start of the season and 6,306 reported no such history (NH). Median age of the cohort was 15.4 ± 1.6 years, and students were followed for an average of 1.3 ± 0.6 years. A history of concussions (OR 2.31, P < 0.0001) was associated with CH. Specifically, a greater number of past concussions (r2 = 0.95) as well as concussions characterized by a loss of consciousness (P < 0.0001) were associated with more severe headache burden. The CH cohort had a greater future incidence of concussion than the NH cohort (55.6 vs. 43.0 per 100 patient-years, P < 0.0001). However, multivariate analysis controlling for demographic, clinical, academic, and sports-related variables yielded no such effect (OR 0.99, P = 0.85). On multivariable analysis the CH cohort did have greater deviations from baseline to PI and FU in Symptom Score (PI OR per point 1.05, P = 0.01, FU OR per point 1.11, P = 0.04) and Processing Speed (OR per point 1.08, P = 0.04), suggesting greater concussion severity and impaired symptomatic recovery as compared to the NH cohort. CONCLUSION: A history of concussions was a significant contributor to headache burden among American adolescents and young adults. However, those with chronic headaches were not more likely to be diagnosed with a concussion, despite presenting with more severe concussions that had protracted recovery. Our findings not only suggest the need for conservative management among youth athletes with chronic headaches, they also indicate a potential health care gap in this population, in that those with chronic headaches may be referred for concussion diagnosis and management at lower rates than those with no such comorbidity.

Evaluation of differences across age groups in the incidence, severity, and recovery of concussion in adolescent student-athletes from 2009 to 2019.

OBJECTIVE: Concussion incidence is known to be highest in children and adolescents; however, there is conflicting evidence about the effect of age on concussion risk and recovery within the adolescent age range. The heterogeneity of results may be partially due to the use of age groupings based on convenience, making comparisons across studies difficult. This study evaluated the independent effect of age on concussion incidence, severity, and recovery in student-athletes aged 12-18 years using cluster analysis to define groupings. METHODS: Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) scores of 11,403 baseline tests and 4922 postinjury tests were used to calculate the incidence rates for adolescent student-athletes grouped into 3 age bands (12-13, 14-15, and 16-18 years of age) on the basis of clustering analysis. The recently created Severity Index was used to compare concussion severity between groups. Follow-up tests for subjects who sustained a concussion were used to evaluate recovery time. The chi-square test and 1-way ANOVA were used to compare differences in demographic characteristics and concussion incidence, severity, and recovery. Multivariable logistic and linear regressions were used to evaluate the independent effects of age on concussion incidence and severity, respectively. Multivariable Cox hazard regression was used to evaluate differences in recovery time. Further analyses were conducted to directly compare findings across studies on the basis of the age groupings used in prior studies. RESULTS: Multivariable regression analyses demonstrated that the 14- to 15-year-old age group had a significantly higher concussion incidence than both the 12- to 13-year-old (14- to 15-year-old group vs 12- to 13-year-old group, OR 1.57, 95% CI 1.16-2.17, p = 0.005) and 16- to 18-year-old (16- to 18-year-old group vs 14- to 15-year-old group, OR 0.79, 95% CI 0.69-0.91, p = 0.0008) age groups. There was no difference in incidence between the 12- to 13-year-old and 16- to 18-year-old groups (16- to 18-year group vs 12- to 13-year group, OR 1.26, 95% CI 0.93-1.72, p = 0.15). There were also no differences in concussion severity or recovery between any groups. CONCLUSIONS: This study found that concussion incidence was higher during mid-adolescence than early and late adolescence, suggesting a U-shaped relationship between age and concussion risk over the course of adolescence. Age had no independent effect on concussion severity or recovery in the 12- to 13-, 14- to 15-, and 16- to 18-year-old groups. Further analysis of the various age groups revealed that results may vary significantly with minor changes to groupings, which may explain the divergent results in the current literature on this topic. Thus, caution should be taken when interpreting the results of this and all similar studies, especially when groupings are based on convenience.

Effects of a history of headache and migraine treatment on baseline neurocognitive function in young athletes.

OBJECTIVE/BACKGROUND: Despite the prevalence of concussions in young athletes, the impact of headaches on neurocognitive function at baseline is poorly understood. We analyze the effects of a history of headache treatment on baseline ImPACT composite scores in young athletes. METHODS: A total of 11,563 baseline ImPACT tests taken by 7,453 student-athletes ages 12-22 between 2009 and 2019 were reviewed. The first baseline test was included. There were 960 subjects who reported a history of treatment for headache and/or migraine (HA) and 5,715 controls (CT). The HA cohort included all subjects who self-reported a history of treatment for migraine or other type of headache on the standardized questionnaire. Chi-squared tests were used to compare demographic differences. Univariate and multivariate regression analyses were used to assess differences in baseline composite scores between cohorts while controlling for demographic differences and symptom burden. RESULTS: Unadjusted analyses demonstrated that HA was associated with increased symptoms (ß=2.30, 95% CI: 2.18-2.41, p<.0001), decreased visual memory (ß=-1.35, 95% CI: -2.62 to -0.43, p=.004), and increased visual motor speed (ß=0.71, 95% CI: 0.23-1.19, p=.004) composite scores. Baseline scores for verbal memory, reaction time, and impulse control were not significantly different between cohorts. Adjusted analyses demonstrated similar results with HA patients having greater symptom burden (ß=1.40, 95% CI: 1.10-1.70, p<.0001), lower visual memory (ß=-1.25, 95% CI: -2.22 to -0.27, p=.01), and enhanced visual motor speed (ß=0.60, 95% CI: 0.11-1.10, p=.02) scores. CONCLUSION: HA affected symptom, visual motor speed, and visual memory ImPACT composite scores. Visual memory scores and symptom burden were significantly worse in the HA group while visual motor speed scores were better, which may have been due to higher stimulant use in the HA group. The effects of HA on visual motor speed and visual memory scores were independent of the effects of the increased symptom burden.

High altitude modulates concussion incidence, severity, and recovery in young athletes.

BACKGROUND: High altitude may affect concussion, but prior studies are limited . We tested whether high altitude affects sport-related concussion (SRC) incidence, severity, and recovery. METHODS: Twenty-five thousand eight hundred fifteen baseline and post-injury Immediate Post-Concussion Assessment and Cognitive Testing results were compiled from Florida and Colorado, low (27 m or 62 m) and high (1,640 m or 1,991 m) altitude locations, respectively. Incidence, severity, and recovery of injury were compared between altitudes. RESULTS: High altitude was associated with increased suspected concussion incidence (adjusted OR, 2.04 [95% CI, 1.86 to 2.24];P < .0001). However, high altitude was associated with lower concussion severity measured by Severity Index (SI) (adjusted OR, 0.42 [95% CI, 0.37 to 0.49];P < .0001). High altitude was associated with decreased recovery from post-concussive symptoms in the migraine (ß, -2.72 [95% CI, -3.31 to -2.13]; P < .0001), cognitive (ß, -1.88 [95% CI, -2.40 to -1.36]; P < .0001), and sleep symptom clusters (ß, -0.30 [95% CI, -0.52 to -0.08]; P = .007). Athletes with initial SI≥8 showed prolonged neurocognitive dysfunction at high altitude (HR, 1.38 [95% CI, 1.06 to 1.81]; P = .02). CONCLUSIONS: High altitude was associated with increased suspected concussions and prolonged recovery but less severe initial injury.

Incidence and Severity of Concussions Among Young Soccer Players Based on Age, Sex, and Player Position.

BACKGROUND: Previously studied risk factors for sports-related concussion in soccer players include sex, age, and player position. However, prior studies were limited in number, they reported conflicting results, and most did not assess initial concussion severity. PURPOSE/HYPOTHESIS: The purpose of this study was to conduct an in-depth analysis of soccer players across key demographic groups (sex, age, position) for both concussion incidence and severity. It was hypothesized that concussion incidence and severity would be higher among male players, players aged ≥17 years, and goalkeepers. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The authors analyzed baseline and postinjury ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) scores for athletes aged 12 to 22 years between July 2009 and June 2019. Players were assigned to an age group based on when they had their most recent baseline test. Concussion incidence and concussion severity index were compared using t tests and multivariate logistic regression. RESULTS: For 1189 individuals who reported soccer as their primary sport, 1032 contributed 1754 baseline ImPACT tests (some individuals had multiple baseline tests), whereas 445 individuals were suspected of sustaining a concussion and then referred for a postinjury 1 test. Of these players, 254 (24.6%) had both a baseline and a postinjury test and were analyzed for concussion severity. Linear regression showed that forwards had a lower incidence of ImPACT-proxied concussions than goalkeepers had (P = .008). Female players had a significantly higher incidence of ImPACT concussions compared with male players (mean, 0.07 [female] vs 0.04 [male] concussions per person-year; P = .05). Players in the ≥17-year age group had a higher incidence of ImPACT concussions than players in the 15- to 16-year age group (P = .04), although the 15- to 16-year age group had more severe concussions than the ≥17-year age group (mean severity index, 2.91 [age 15-16 years] vs 1.73 [age ≥17 years]; P = .001). CONCLUSION: Female soccer players experienced a higher incidence of concussion than did male players, and goalkeepers experienced a greater incidence of ImPACT concussions than did forwards. Players of both sexes and all positions in the 15- to 16-year age group showed increased initial concussion severity compared with the ≥17-year age group, despite a lower comparative incidence of ImPACT concussions. Further study is needed to understand whether sex and player position affect concussion severity.

Sport Contact Level Affects Post-Concussion Neurocognitive Performance in Young Athletes.

OBJECTIVE: Contact level affects the incidence of sports-related concussion. However, the effects of contact level on injury severity and recovery are less clear and are the focus of this study. METHOD: Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) for athletes aged 12-22 was performed at baseline (n = 10,907 for 7,058 athletes), after suspected concussion determined by physicians or athletic trainers (n = 5,062 for 4,419 athletes), and during follow-up visits (n = 3,264 for 2,098 athletes). Athletes played contact/collision (CC), limited contact (LC), and noncontact (NC) sports. Injury incidence, severity, and recovery were measured using raw and change from baseline neurocognitive test scores. Comparisons between groups used univariate analysis and multivariable regression controlling for demographic variables. RESULTS: Compared to CC athletes, LC and NC athletes showed decreased suspected concussion incidence. At initial post-injury testing, all neurocognitive test scores were similar between groups except changes from baseline for processing speed were improved for LC compared to CC athletes. Upon follow-up testing, raw neurocognitive scores were better for NC compared to the contact collision athletes in verbal memory, processing speed, total symptom score, migraine cluster, cognitive cluster, and neuropsychiatric cluster scores. For change from baseline scores, LC athletes exhibited better performance on verbal memory, processing speed, and reaction time but also showed higher neuropsychiatric scores than CC athletes. CONCLUSION: Neurocognitive scores between contact levels were similar at the first post-injury test. However, follow up showed many improved scores and symptoms for limited and NC sports compared to CC sports, which may indicate faster recovery.

Impact of Psychiatric Illnesses and Selective Serotonin Reuptake Inhibitor Medications on Baseline Neurocognitive Testing.

INTRODUCTION: Neurocognitive tests are an integral component of sport-related concussion (SRC) workup. A history of psychiatric illness (HPI) is common among young athletes. Investigations of factors that influence athletes' baseline neurocognitive function are crucial for an accurate assessment of SRC. OBJECTIVE: In this study, we aim to elucidate the effect of HPI and selective-serotonin reuptake inhibitor (SSRI) medication use on baseline neurocognitive performance in young athletes. METHODS: We conducted a retrospective cross-sectional study of Immediate Post-Concussion Assessment and Cognitive Testing assessments. A total of 268 athletes with HPI and a control group of 6,364 athletes were included. The outcomes were total symptom score based on post-concussion symptom scale, verbal memory, visual memory, visual motor, reaction time, and impulse control scores with self-reported HPI status and SSRI use. RESULTS: Athletes with HPI had an elevated symptom score in both univariate analysis (p < .0001) and multivariate analysis (p < .0001). HPI influence on visual memory score was not robust to multivariate analysis (p = .24). Athletes with HPI who reported SSRI medication use had the same baseline neurocognitive performance as other athletes with HPI. HPI influences athletes' baseline neurocognitive performance by elevating symptom scores. HPI does not alter any of the objective neurocognitive composite scores in contrast to previous work. CONCLUSIONS: Clinicians should consider the impact of HPI on baseline neurocognitive performance during the assessment of a suspected SRC. Additional research is required to bolster our findings on SSRI use and ascertain the effects of other drug classes on baseline neurocognitive performance.

A Multivariable Analysis to Evaluate the Presence or Absence of Gender Differences in Baseline ImPACT Composite Scores and Symptom Severity Ratings in Student-Athletes Ages 12-18 Years.

INTRODUCTION: Gender differences in neurocognitive function have been reported over the past few decades. However, multiple studies that report gender differences in Immediate Post-Concussion Assessment and Cognitive Tests composite scores ignore potential confounders which may lead to inaccurate results. METHODS: A total of 4829 male and 2477 female baseline Immediate Post-Concussion Assessment and Cognitive Tests from 2009 to 2019 of subjects ages 12-18 years were used to evaluate gender differences in baseline neurocognitive scores and symptom severity ratings. Regression analyses were used to assess the effects of gender on neurocognitive performance at baseline while controlling for a number of potential confounders including symptom burden at the time of testing. RESULTS: Differences in 3 of 5 composite scores as well as severity rating scores were maintained in multivariate analysis. Females had increased Post-Concussion Symptom Scale (ß = 3.54, 95% confidence interval, 2.91 to 4.16, P < .0001) along with higher verbal memory (ß = 1.82, 95% confidence interval, 1.15 to 2.50, P < .0001) and visual motor (ß = 1.29, 95% confidence interval, 0.85-1.72, P < .0001) scores. CONCLUSIONS: Statistically significant gender differences were found in baseline neurocognitive function. This study clarifies for the first time that gender differences in these neurocognitive domains are not simply an artifact of differences in symptom burden. However, the small effect sizes call into question the clinical relevance of these differences.

Concussion Incidence and Recovery Among Youth Athletes With ADHD Taking Stimulant-Based Therapy.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) may affect concussion risk and recovery in youth athletes. PURPOSE: To evaluate the association between incidence of concussion and postinjury recovery of symptoms and neurocognitive dysfunction among youth athletes with ADHD and differential stimulant use. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: From 2009 to 2019, the authors administered the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) to youth athletes at the beginning of each season. Throughout the season, athletes with concussions were examined and readministered the ImPACT both postinjury and again 7 days after the postinjury administration. These athletes (N = 7453) were divided into those with ADHD on stimulant-based therapy (ADHD+meds; n = 167), those with ADHD not on stimulant-based therapy (ADHD-only; n = 354), and those with no ADHD (non-ADHD; n = 6932). Recovery of neurocognitive dysfunction at postinjury and follow-up was calculated using the ImPACT symptom score, verbal memory, visual memory, visual motor skills, and reaction time (calculated as standardized deviations from baseline). Univariate results were confirmed with multivariate analysis. RESULTS: The ADHD+meds cohort had a lower incidence of concussion (37.3 concussions per 100 patient-years) compared with the ADHD-only group (57.0 concussions per 100 patient-years) (odds ratio [OR], 0.51 [95% CI, 0.37-0.71]; P < .0001) and non-ADHD group (52.8 concussions per 100 patient-years) (OR, 0.50 [95% CI, 0.37-0.67]; P < .0001). At postinjury, ImPACT scores were elevated from baseline to a similar extent in the ADHD+meds cohort compared with the other 2 groups. By follow-up, however, deviations from baseline were lower among the ADHD+meds group compared with the non-ADHD group in verbal memory (OR, 0.46 [95% CI, 0.28-0.76]; P = .002), visual memory (OR, 0.27 [95% CI, 0.10-0.66]; P = .005), and visual motor skills (OR, 0.58 [95% CI, 0.33-0.99]; P = .048). The deviation at follow-up was also lower among the ADHD+meds group compared with the ADHD-only group in visual memory (OR, 0.56 [95% CI, 0.33-0.96]; P = .04) and visual motor skills (OR, 0.42 [95% CI, 0.22-0.81]; P = .01). CONCLUSION: Stimulant use among youth athletes with ADHD was independently associated with reduced incidence for concussion and lower deviation from baseline in verbal memory, visual memory, and visual motor skills at 7 days postconcussion, suggesting lower neurocognitive impairment at follow-up in this group versus their peers.

Nonsteroidal anti-inflammatory drug use and concussions in adolescent athletes: incidence, severity, and recovery.

OBJECTIVE: Given concerns about the potential long-term effects of concussion in young athletes, concussion prevention has become a major focus for amateur sports leagues. Athletes have been known to frequently use anti-inflammatory medications to manage injuries, expedite return to play, and treat concussion symptoms. However, the effects of baseline nonsteroidal anti-inflammatory drug (NSAID) use on the susceptibility to head injury and concussion remain unclear. This study aims to assess the effects of preinjury NSAID use on concussion incidence, severity, and recovery in young athletes. METHODS: Data from 25,815 ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) tests were obtained through a research agreement with ImPACT Applications Inc. Subjects ranged in age from 12 to 22 years old. Those who reported NSAID use at baseline were assigned to one (anti-inflammatory [AI]) cohort, whereas all others were assigned to the control (CT) cohort. Differences in head trauma and concussion incidence, severity, and recovery were assessed using chi-square tests, unpaired t-tests, and Kaplan-Meier plots. RESULTS: The CT cohort comprised a higher percentage (p < 0.0001) of males (66.30%) than the AI cohort (44.16%) and had a significantly greater portion of athletes who played football (p = 0.004). However, no statistically significant differences were found between the two cohorts in terms of the incidence of head trauma (CT = 0.489, AI = 0.500, p = 0.9219), concussion incidence (CT = 0.175, AI = 0.169, p = 0.7201), injury severity, or median concussion recovery time (CT = 8, AI = 8, p = 0.6416). In a multivariable analysis controlling for baseline differences between the cohorts, no association was found between NSAID use and concussion incidence or severity. CONCLUSIONS: In this analysis, the authors found no evidence that preinjury use of NSAIDs affects concussion risk in adolescent athletes. They also found no indication that preinjury NSAID use affects the severity of initial injury presentation or concussion recovery.

Sex-Related Differences in the Incidence, Severity, and Recovery of Concussion in Adolescent Student-Athletes Between 2009 and 2019.

BACKGROUND: The sex of an athlete is thought to modulate concussion incidence; however, the effects of sex on concussion severity and recovery are less clear. PURPOSE: To evaluate sex differences in concussion severity and recovery using a large, heterogeneous sample of young student-athletes with the goal of understanding how sex affects concussion outcomes in young athletes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The Immediate Post-Concussion Assessment and Cognitive Testing results of 11,563 baseline and 5216 postinjury tests were used to calculate the incidence of concussion of adolescent male and female student-athletes ages 12 to 22 years (median, 15 years). The postinjury tests of 3465 male and 1751 female student-athletes evaluated for concussion or head trauma were used to assess differences in the Severity Index (SI) and recovery. Chi-square tests and t tests were used to compare differences in demographic characteristics, incidence, and SI between the 2 cohorts. Multivariable linear, logistic, and Cox proportional hazards regressions were used to control for differences between cohorts in analyses of incidence, SI, and recovery. RESULTS: When we controlled for demographic differences, female participants had higher odds of concussion (odds ratio, 1.62; 95% CI, 1.40-1.86; P < .0001) and higher SI after concussion (ß = 0.67; 95% CI, 0.02-1.32; P = .04). This discrepancy in SI was a result of differences in Symptom (2.40 vs 2.94; P < .0001) and Processing Speed (0.91 vs 1.06; P = .01) composite scores between male and female participants, respectively. We found no effect of sex on time to recovery when controlling for initial concussion SI (hazard ratio, 0.94; 95% CI, 0.78-1.12; P = .48). CONCLUSION: Using large, multisport cohorts, this study provides evidence that female athletes are at higher risk for more concussions and these concussions are more severe, but male and female athletes have similar recovery times when the analysis controls for initial concussion SI.

Incidence of concussion and recovery of neurocognitive dysfunction on ImPACT assessment among youth athletes with premorbid depression or anxiety taking antidepressants.

OBJECTIVE: Concussions in youth sports comprise an estimated 1.6-3.8 million annual injuries in the US. Sex, age, and attention-deficit hyperactivity disorder (ADHD) have been identified as salient risk factors for concussion. This study seeks to evaluate the role of premorbid depression or anxiety (DA), with or without antidepressant use, on the incidence of concussion and the recovery of symptoms and neurocognitive dysfunction after concussion. METHODS: Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) was administered to 7453 youth athletes at baseline. Throughout the season, concussions were examined by physicians and athletic trainers, followed by readministration of ImPACT postinjury (PI) and again at follow-up, a median of 7 days PI. Individuals were divided into three categories: 1) unmedicated athletes with DA (DA-only, n = 315), athletes taking antidepressants (DA-meds, n = 81), and those without DA or antidepressant use (non-DA, n = 7039). Concussion incidence was calculated as the total number of concussions per total number of patient-years. The recovery of neurocognitive measures PI was calculated as standardized deviations from baseline to PI and then follow-up in the 5 composite ImPACT scores: symptom score, verbal memory, visual memory, visual motor skills, and reaction time. Univariate results were confirmed with multivariate analysis. RESULTS: There was no difference in concussion incidence between the DA-only cohort and the non-DA group. However, the DA-meds group had a significantly greater incidence of concussion than both the DA-only group (OR 2.67, 95% CI 1.88-7.18, p = 0.0001) and the non-DA group (OR 2.19, 95% CI 1.16-4.12, p = 0.02). Deviation from baseline in PI symptom scores was greater among the DA-meds group as compared to the non-DA group (OR 1.14, 95% CI 1.01-1.28, p = 0.03). At follow-up, the deviation from baseline in symptom scores remained elevated among the DA-meds group as compared to the non-DA group (OR 1.62, 95% CI 1.20-2.20, p = 0.002) and the DA-only group (OR 1.87, 95% CI 1.12-3.10, p = 0.02). Deviation from baseline in follow-up verbal memory was also greater among the DA-meds group as compared to both the non-DA group (OR 1.57, 95% CI 1.08-2.27, p = 0.02) and the DA-only group (OR 1.66, 95% CI 1.03-2.69, p = 0.04). CONCLUSIONS: Premorbid DA itself does not seem to affect the incidence of concussion or the recovery of symptoms and neurocognitive dysfunction PI. However, antidepressant use for DA is associated with 1) increased concussion incidence and 2) elevated symptom scores and verbal memory scores up to 7 days after concussion, suggesting impaired symptomatic and neurocognitive recovery on ImPACT.

Effects of Recurrent Mild Traumatic Brain Injuries on Incidence, Severity, and Recovery of Concussion in Young Student-Athletes.

OBJECTIVE: To examine the effects of recurrent concussions on the incidence, severity, and recovery of significant neurocognitive dysfunction (SND) in young athletes. SETTING: Various US youth sports organizations that utilize Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) for baseline and postinjury concussion testing. PARTICIPANTS: Data from 11 563 ImPACT baseline evaluations of US student-athletes aged 12 to 22 years were separated into 2 cohorts: subjects reporting 2 or more previous concussions (PC; n = 976 baseline evaluations) at baseline and a control group reporting zero previous concussions (CT; n = 7743 baseline evaluations). Subjects reporting 1 prior concussion were excluded. DESIGN: Retrospective cohort. MAIN MEASURES: Differences in SND incidence, severity, and recovery between the 2 cohorts were assessed using chi-squared tests, t tests, survival analyses, and multivariate regressions. RESULTS: The PC cohort had a higher incidence of head injury leading to ImPACT (436.7 per 1000 person-years vs 194.4 per 1000 person-years, P < .0001) and a higher incidence of SND (140.4 vs 71.8, P < .0001) than controls. However, the Severity Index (SI) demonstrated that SND severity was lower in the PC group (7.55 vs 8.59, P = .04). Adjusted analyses similarly demonstrated that the PC cohort had increased SND incidence (odds ratio = 1.93; 95% CI, 1.61 to 2.31; P < .0001), decreased SI (ß = -1.37; 95% CI, -2.40 to -0.34; P = .009), and equivalent recovery (hazard ratio = 0.98; 95% CI, 0.76 to 1.72; P = .90). CONCLUSION: Participants with a history of concussion have a higher incidence of SND but present with lower severity SND, which may be a result of increased concussion education or symptom awareness. Recurrent concussion has no significant impact on acute neurocognitive recovery. Together, these results provide evidence against the supposition that a history of concussion increases the severity of future SND.

Policy Interventions, Social Distancing, and SARS-CoV-2 Transmission in the United States: A Retrospective State-level Analysis.

BACKGROUND: Various non-pharmaceutical interventions (NPIs) such as stay-at-home orders and school closures have been employed to limit the spread of Coronavirus disease (COVID-19). This study measures the impact of social distancing policies on COVID-19 transmission in US states during the early outbreak phase to assess which policies were most effective. METHODS: To measure transmissibility, we analyze the average effective reproductive number (Rt) in each state the week following its 500th case and doubling time from 500 to 1000 cases. Linear and logistic regressions were performed to assess the impact of various NPIs while controlling for population density, GDP, and certain health metrics. This analysis was repeated for deaths with doubling time to 100 deaths with several healthcare infrastructure control variables. RESULTS: States with stay-at-home orders in place at the time of their 500th case were associated with lower average Rt the following week compared to states without them (p<0.001) and significantly less likely to have an Rt>1 (OR 0.07, 95% CI 0.01-0.37, p = 0.004). These states also experienced longer doubling time from 500 to 1000 cases (HR 0.35, 95% CI 0.17-0.72, p = 0.004). States in the highest quartile of average time spent at home were also slower to reach 1000 cases than those in the lowest quartile (HR 0.18, 95% CI 0.06-0.53, p = 0.002). CONCLUSIONS: Stay-at-home orders had the largest effect of any policy analyzed. Multivariate analyses with cellphone tracking data suggest social distancing adherence drives these effects. States that plan to scale back such measures should carefully monitor transmission metrics.