Relationship of Attention Deficit Hyperactivity Disorder and Postconcussion Recovery in Youth Athletes

Variables associated with days of school missed following concussion: results from the Sport Concussion Outcomes in PEdiatrics (SCOPE) study

OBJECTIVE

To understand factors associated with missed academic time after concussion to improve support for patients. Our goal was to assess patient-specific predictors of total school time lost after pediatric/adolescent concussion.

STUDY DESIGN

We performed a prospective cohort study of children and adolescents (8-18 years of age) seen within 14 days of concussion from seven pediatric medical centers across the United States. We collected outcomes via the Concussion Learning Assessment & School Survey (CLASS) and constructed a multivariable predictive model evaluating patient factors associated with school time loss.

RESULTS

167 patients participated (mean age = 14.5 ± 2.2 years; 46% female). Patients were assessed initially at 5.0 ± 3.0 days post-injury and had a final follow-up assessment 24.5 ± 20.0 days post-concussion. Participants missed a median of 2 days of school (IQR = 0.5-4), and 21% reported their grades dropped after concussion. Higher initial symptom severity rating (β = 0.06, 95% CI = 0.03-0.08, p < 0.001) and perception of grades dropping after concussion (β = 1.37, 95% CI = 0.28-2.45, p = 0.01) were significantly associated with more days of school time missed after concussion. Those who reported their grades dropping reported missing significantly more school (mean = 5.0, SD = 4.7 days missed of school) than those who reported their grades did not drop (mean = 2.2, SD = 2.6 days missed of school; p < 0.001; Cohen's d = 0.87).

CONCLUSIONS

Children and adolescents reported missing a median of 2 days of school following concussion, and more missed school time after a concussion was associated with more severe concussion symptoms and perception of grades dropping. These findings may support recommendations for minimal delays in return-to-learn after concussion.

Association Between First Attempt Buffalo Concussion Treadmill Test and Days to Recovery in 855 Children With Sport-Related Concussion: A Historical Cohort Study and Prognostic Factors Analysis

OBJECTIVE

Little is known about the prognostic value of the Buffalo Concussion Treadmill Test (BCTT) after the acute phase of sport-related concussion (SRC). We examined the added prognostic value of the BCTT performed 10 to 21 days after SRC in children, in addition to participant, injury, and clinical process characteristics on days to recovery.

DESIGN

Historical clinical cohort study.

SETTING

Network of approximately 150 Canadian multidisciplinary primary-care clinics.

PARTICIPANTS

855 children (mean age 14 years, range 6-17 years, 44% female) who presented between January 2016, and April 2019 with SRC.

ASSESSMENT OF RISK FACTORS

Participant, injury, and clinical process characteristics, with focus on BCTT exercise intolerance assessed 10 to 21 days after injury.

OUTCOME

Days to clinical recovery.

RESULTS

Children who were exercise intolerant experienced an increase of 13 days to recovery (95% CI, 9-18 days). Each additional day between SRC and first BCTT was associated with a recovery delay of 1 day (95% CI, 1-2 days), and prior history of concussion was associated with a recovery delay of 3 days (95% CI, 1-5 days). Participant, injury, and clinical process characteristics, and the first attempt BCTT result explained 11% of the variation in recovery time, with 4% accounted for by the BCTT.

CONCLUSION

Exercise-intolerance assessed 10 to 21 days after SRC was associated with delayed recovery. However, this was not a strong prognostic factor for days to recovery.

A Prospective Cohort Study of the Association Between Preinjury Psychosocial Function and Postconcussive Symptoms in Pediatric Mild Traumatic Brain Injury: An A-CAP Study

OBJECTIVE

We evaluated the moderating effect of preinjury psychosocial function on postconcussion symptoms for children with mild traumatic brain injury (mTBI).

DESIGN, SETTING, AND POPULATION

We conducted a prospective cohort study of children ages 8.0 to 16.9 years with mTBI ( n = 633) or orthopedic injury (OI; n = 334), recruited from 5 pediatric emergency departments from September 2016 to December 2018.

MAIN MEASURES

Participants completed baseline assessments within 48 hours of injury, and postconcussion symptoms assessments at 7 to 10 days, weekly to 3 months, and biweekly to 6 months post-injury. Preinjury psychosocial function was measured using parent ratings on the Pediatric Quality of Life Inventory (PedsQL) and the Strengths and Difficulties Questionnaire (SDQ), retrospectively evaluating their child's status prior to the injury. Parent and child ratings on the Health and Behavior Inventory (HBI) (cognitive and somatic subscales) and the Post-Concussion Symptom Interview (PCS-I) were used as measures of postconcussion symptoms. We fitted 6 longitudinal regression models, which included 747 to 764 participants, to evaluate potential interactions between preinjury psychosocial function and injury group as predictors of child- and parent-reported postconcussion symptoms.

RESULTS

Preinjury psychosocial function moderated group differences in postconcussion symptoms across the first 6 months post-injury. Higher emotional and conduct problems were significantly associated with more severe postconcussion symptoms among children with mTBI compared with OI. Wald's χ 2 for interaction terms (injury group × SDQ subscales) ranged from 6.3 to 10.6 ( P values <.001 to .043) across parent- and child-reported models. In contrast, larger group differences (mTBI > OI) in postconcussion symptoms were associated with milder hyperactivity (Wald's χ 2 : 15.3-43.0, all P < .001), milder peer problems (Wald's χ 2 : 11.51, P = .003), and higher social functioning (Wald's χ 2 : 12.435, P = .002).

CONCLUSIONS

Preinjury psychosocial function moderates postconcussion symptoms in pediatric mTBI, highlighting the importance of assessing preinjury psychosocial function in children with mTBI.

Premorbid Risk Factors and Acute Injury Characteristics of Sport-Related Concussion Across the National Collegiate Athletic Association: Findings from the Concussion Assessment, Research, and Education (CARE) Consortium

BACKGROUND

Previous sport-related concussion research highlights post-injury characteristics that influence recovery trajectories; however, there is limited information regarding premorbid factors that affect sport-related concussion risk.

OBJECTIVE

We aimed to (a) compare premorbid demographic factors among a large cohort of collegiate student athletes who did or did not sustain a sport-related concussion and (b) assess differences in acute injury characteristics based on biological sex and contact level.

METHODS

We conducted a cohort study of university student athletes from 22 sports enrolled in the Concussion Assessment, Research, and Education (CARE) Consortium study from 2014 to 2021 (n = 1804 student athletes with sport-related concussions; n = 21,702 student athletes without sport-related concussions).

RESULTS

Statistical analyses indicated student athletes who self-identified as Black (odds ratio [OR] = 1.61; 95% confidence interval [CI] = 1.42, 1.81) or multiracial (OR = 1.32; 95% CI 1.10, 1.59) demonstrated greater odds of experiencing sport-related concussions than White-identifying student athletes. Additional findings suggest male athletes (OR = 1.47; 95% CI 1.20, 1.81) and contact sport student athletes (OR = 1.40; 95% CI 1.16, 1.70) may be at increased odds for sport-related concussions if they were previously diagnosed with attention deficit hyperactive disorder. Notable post-injury characteristics across sexes included differences in the incident loss of consciousness (male: 5.9%, female: 2.6%; p < 0.001), post-traumatic amnesia (male: 13.6%, female: 5.1%; p < 0.001), and retrograde amnesia (male: 6.8%, female: 2.8%; p < 0.001). A greater proportion of contact-sport student athletes experienced an altered mental status (52.7%) than limited contact (36.2%) and non-contact (48.6%) [p < 0.001]. Last, student athletes participating at lower contact levels were more likely to have a longer delay in removal from activity following injury (contact: 73.6 ± 322.2 min; limited contact: 139.1 ± 560.0 min; non-contact: 461.4 ± 1870.8 min; p = 0.005).

CONCLUSIONS

The present study provides contemporary pre- and post-sport-related concussion injury characteristics using a considerably sized cohort of collegiate student athletes. These findings support previous work suggesting sport-related concussion results in complex individualized clinical presentations, which may influence management strategies.

When should an athlete retire or discontinue participating in contact or collision sports following sport-related concussion? A systematic review

OBJECTIVE

To systematically review the scientific literature regarding factors to consider when providing advice or guidance to athletes about retirement from contact or collision sport following sport-related concussion (SRC), and to define contraindications to children/adolescent athletes entering or continuing with contact or collision sports after SRC.

DATA SOURCES

Medline, Embase, SPORTSDiscus, APA PsycINFO, CINAHL and Cochrane Central Register of Controlled Trials were searched systematically.

STUDY ELIGIBILITY CRITERIA

Studies were included if they were (1) original research, (2) reported on SRC as the primary source of injury, (3) evaluated the history, clinical assessment and/or investigation of findings that may preclude participation in sport and (4) evaluated mood disturbance and/or neurocognitive deficits, evidence of structural brain injury or risk factors for increased risk of subsequent SRC or prolonged recovery.

RESULTS

Of 4355 articles identified, 93 met the inclusion criteria. None of the included articles directly examined retirement and/or discontinuation from contact or collision sport. Included studies examined factors associated with increased risk of recurrent SRC or prolonged recovery following SRC. In general, these were low-quality cohort studies with heterogeneous results and moderate risk of bias. Higher number and/or severity of symptoms at presentation, sleep disturbance and symptom reproduction with Vestibular Ocular Motor Screen testing were associated with prolonged recovery and history of previous concussion was associated with a risk of further SRC.

CONCLUSION

No evidence was identified to support the inclusion of any patient-specific, injury-specific or other factors (eg, imaging findings) as absolute indications for retirement or discontinued participation in contact or collision sport following SRC.

PROSPERO REGISTRATION NUMBER

CRD42022155121.

Athletes With Attention-Deficit/Hyperactivity Disorder: Position Statement of the American Medical Society for Sports Medicine

ABSTRACT

Athletes of all ages may be affected by medical and mental health issues. Sports medicine physicians should be familiar with common conditions that may affect the well-being of athletes, such as attention-deficit/hyperactivity disorder (ADHD). ADHD behaviors have the potential to affect a person's ability to concentrate. It is likely that social and cognitive therapies combined with pharmacotherapy will be the most effective way to treat ADHD in athletes. Medications used for ADHD, especially stimulant types, are known to improve alertness, reaction time, anaerobic performance, and endurance, which would potentially improve athletic performance. Furthermore, stimulant medications may enable student athletes with ADHD to focus on academic studies for longer periods of time, beyond usual levels of fatigue, important for those who may be exhausted after practices and games. The purported performance enhancement effects and potential adverse effects of stimulant medications have prompted many sports governing bodies to ban prescription stimulants or establish strict rules for their use. Athletes taking physician-prescribed stimulants to treat ADHD need to provide the appropriate documentation for approval before competition or risk punitive measures. Physicians should strive to provide a high quality of care to athletes with ADHD through early diagnosis, appropriate and careful multidisciplinary treatment, and complete and timely documentation to facilitate continued sports participation.

Attention-Deficit Hyperactivity Disorder and Learning Disabilities Modify Recovery and Sport Behavior Following Sport-Related Concussion

Limited evidence exists concerning how a diagnosis of attention-deficit hyperactivity disorder and/or learning disabilities (ADHD/LD) modifies recovery and behavior following sport-related concussion (SRC). To understand how ADHD/LD modifies the post-SRC experience, we conducted a retrospective cohort study of concussed young athletes through phone interviews with patients and guardians. Outcomes included time until symptom resolution (SR) and return-to-learn (RTL), plus subjective changes in post-SRC activity and sports behavior. Multivariate Cox and logistic regression was performed, adjusting for biopsychosocial characteristics. The ADHD/LD diagnosis was independently associated with worse outcomes, including lower likelihood to achieve SR (hazard ratio [HR] = 0.62, 95% confidence interval [CI] = [0.41-0.94]; P = .02) and RTL (HR = 0.55, 95% CI = [0.36-0.83]; P < .01) at any time following injury, and increased odds of changing sport behavior after concussion (odds ratio [OR] = 3.26, 95% CI = [1.26-8.42], P = .02), often to a safer style of play (62.5% vs 39.6%; P = .02) or retiring from the sport (37.5% vs 18.5%; P = .02). These results provide further evidence of the unique needs for athletes with ADHD/LD following SRC.

The Effects of Attention-Deficit/Hyperactivity Disorder Symptoms on the Association between Head Impacts and Post-Season Neurocognitive and Behavioral Outcomes

OBJECTIVE

Having attention-deficit/hyperactivity disorder (ADHD) is a risk factor for concussion that impacts concussion diagnosis and recovery. The relationship between ADHD and repetitive subconcussive head impacts on neurocognitive and behavioral outcomes is less well known. This study evaluated the role of ADHD as a moderator of the association between repetitive head impacts on neurocognitive test performance and behavioral concussion symptoms over the course of an athletic season.

METHOD

Study participants included 284 male athletes aged 13-18 years who participated in high school football. Parents completed the Strengths and Weaknesses of ADHD Symptoms and Normal Behavior (SWAN) ratings about their teen athlete before the season began. Head impacts were measured using an accelerometer worn during all practices and games. Athletes and parents completed behavioral ratings of concussion symptoms and the Attention Network Task (ANT), Digital Trail Making Task (dTMT), and Cued Task Switching Task at pre- and post-season.

RESULTS

Mixed model analyses indicated that neither head impacts nor ADHD symptoms were associated with post-season athlete- or parent-reported concussion symptom ratings or neurocognitive task performance. Moreover, no relationships between head impact exposure and neurocognitive or behavioral outcomes emerged when severity of pre-season ADHD symptoms was included as a moderator.

CONCLUSION

Athletes' pre-season ADHD symptoms do not appear to influence behavioral or neurocognitive outcomes following a single season of competitive football competition. Results are interpreted in light of several study limitations (e.g., single season, assessment of constructs) that may have impacted this study's pattern of largely null results.

Research Trends and Prospects of Sport-Related Concussion: A Bibliometric Study Between 2000 and 2021

BACKGROUND

Research around sport-related concussion (SRC) has made great advances during the twenty-first century. However, few studies have systematically analyzed the published SRC research.

METHODS

A bibliometric analysis was conducted of data from articles from the Web of Science Core Collection database. Descriptive statistics were used to analyze publication trends, most productive countries, institutions, authors, journals, research fields, and references with the highest citation number. VOSviewer software was used to perform network visualization and keywords co-occurrence analysis. CiteSpace software was used to perform reference co-citation analysis.

RESULTS

1) The number of publications and number of citations of research in SRC progressively increased between 2000 and 2021; 2) the United States was the leading country in research in SRC; 3) extensive cooperation among countries, institutions, and investigators was prevalent in SRC research; 4) P. McCrory, M. McCrea, and K.M. Guskiewicz were the 3 most prolific and influential authors; 5) research in SRC involved multidisciplinary perspectives and approaches; 6) research in SRC mainly covered aspects of primary prevention, diagnosis, and management, and the latter two have gained more attention in recent years; and 7) specific questions about "education," "predictors," "youth," "exercise," "reliability," "validity," and "baseline" were the research frontiers of SRC.

CONCLUSIONS

Attention to research in SRC has rapidly increased in recent years. Our work is a holistic overview that summarizes the hotspots, frontiers, and prospects of SRC, thus providing valuable information and guidance concerning research directions for those who are interested in or are dedicated to SRC research.

Clinical Outcome Following Sport-Related Concussion Among Children and Adolescents with a History of Prior Concussion: A Systematic Review

Authoritative sources advise clinicians and parents that a history of prior concussion confers increased risk for worse outcome from a future concussion. However, the strength of the evidence supporting such pronouncements and thus the extent to which clinicians should incorporate this information into their care and management of pediatric concussion is unclear. This systematic review critically analyzed and synthesized the literature on the association between a history of prior concussion and prognosis/clinical outcome following a subsequent sport-related concussion among children and adolescents. The online databases PubMed, MEDLINE®, PsycINFO®, CINAHL, Cochrane Library, EMBASE, SPORTDiscus, Scopus, and Web of Science were searched from inception to May 15, 2021. From 5,118 total records screened, 51 studies (46 cohort studies and 5 case-control studies) met inclusion criteria, reporting concussion recovery or outcome for 26,643 youth. A median of 36% had a prior history of concussion. Across all studies and outcomes, the majority (k=37, 72.5%) did not find a statistically significant association between lifetime history of concussion and outcome from a subsequent concussion. Important methodological limitations in the literature were identified. Available studies do not provide consistent or compelling evidence that children and adolescents with a history of concussions are at increased risk for worse clinical outcome following a subsequent sport-related concussion-although methodological limitations temper the strength of this conclusion. Clinicians are cautioned against routinely treating children and adolescents with one or more prior injuries differently, and more conservatively, because doing so, in some cases, might be counterproductive.

Factors Associated With a Prolonged Time to Return to Play After a Concussion

BACKGROUND

Prognosticating recovery times for individual athletes with a concussion remains a challenge for health care providers. Several preinjury and postinjury factors have been proposed to be predictive of prolonged return-to-play (RTP) times, but the data in this area are still sparse.

PURPOSES

This study aimed to identify risk factors associated with prolonged recovery times and determine which are most predictive of prolonged recovery times in a head-to-head comparison.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

All concussions occurring between September 2017 and August 2020 at a single National Collegiate Athletic Association Division I institution were reviewed and included in this study. Preinjury modifiers including age, sex, sport, concussion history, and past medical problems were collected from the electronic medical records. Postinjury modifiers analyzed included initial and follow-up Sport Concussion Assessment Tool 5th Edition scores, vestibular evaluation findings, and eye tracking results.

RESULTS

A total of 159 athletes and 187 concussion cases were included. Preinjury factors that were correlated with prolonged RTP times included a history of concussions (P = .015), a history of migraines (P = .013), and whether an athlete participated in an individual sport (P = .009). Postinjury factors correlated with prolonged RTP times included the total number (P = .020) and severity (P = .023) of symptoms as well as abnormal Vestibular Ocular Motor Screening findings (P = .002). Overall, 6 different symptoms (balance problems, difficulty concentrating, light sensitivity, drowsiness, fatigue/low energy, and difficulty remembering) were significantly correlated with prolonged RTP times. The study also found that the number and severity of symptoms were additive in a dose-dependent fashion. On multivariable analysis of all these factors, a history of concussions was found to be the most predictive of prolonged RTP times, while participation in an individual sport had the largest effect on recovery times.

CONCLUSION

Several preinjury and postinjury risk factors were identified as being correlated with prolonged recovery times. Many of these risk factors were also found to be additive in nature. This information provides clinicians with a valuable tool in prognosticating and estimating recovery times for athletes. The study also revealed that athletes participating in individual sports had longer RTP times compared with athletes in team sports, which is a novel finding that requires further research.

Attention-Deficit/Hyperactivity Disorder-Related Self-Reported Symptoms Are Associated With Elevated Concussion Symptomatology

The aim of the present investigation was to provide insight into how postconcussion symptomatology may be altered in individuals exhibiting attention-deficit/hyperactivity disorder (ADHD)-related behaviors and examine factors that may be responsible for driving such relationships. A total of 99 individuals were assessed during the subacute phase of concussion recovery. Inattentive symptomatology, but not diagnosis of ADHD, was related to greater concussion-symptom severity and overall symptoms endorsed. Cluster and factor analyses highlighted that the relationship between ADHD symptomatology and concussion symptomatology was not a function of overlapping constructs being assessed (i.e., concussion-related symptomatology was not a proxy of ADHD-related symptomatology). These relationships were not mediated by parental observations of impairments in behaviors associated with executive functioning (i.e., executive dysfunction was not driving the greater concussion-related symptomatology associated with ADHD-related symptomatology). These findings highlight the importance of moving beyond categorical frameworks of ADHD to, instead, consider the continuum of underlying behaviors.

Neuropsychological and neuropsychiatric recovery from mild traumatic brain injury

PURPOSE OF REVIEW

Mild traumatic brain injury (mTBI) is a significant public health concern for children. This review summarizes recent literature on early symptoms and neuropsychiatric and neuropsychological outcomes following pediatric mTBI and highlights factors that predict prolonged recovery. Evidence-based recommendations for assessment and treatment are also discussed.

RECENT FINDINGS

Whereas most children recover within 1 month after mTBI, 10-30% of children experience lingering neuropsychiatric or neuropsychological symptoms 3 months or more after injury. For the subset who experience prolonged recovery, new or worsening emotional and behavioral symptoms are the most frequent concerns. Recent research has suggested that specific factors, including preinjury mental health concerns, female sex, and family characteristics, are associated with increased risk of experiencing prolonged recovery. Early management includes reassurance, brief rest (1-3 days), and gradual return to typical activities. When symptoms linger for more than 4 weeks, evaluation in a specialty clinic is recommended and multimodal therapies are considered. Active recovery models, which include gradual return to aerobic exercise and cognitive behavioral approaches, are promising for the management of prolonged symptoms.

SUMMARY

A minority of children with mTBI experience prolonged neuropsychiatric or neuropsychological concerns. While our understanding of pediatric mTBI is growing, and recommendations for assessment and management have been developed, many gaps remain.

Neurodevelopmental Disorders and Risk of Concussion: Findings from the National Collegiate Athletic Association Department of Defense Grand Alliance Concussion Assessment, Research, and Education (NCAA-DOD CARE) Consortium (2014-2017)

Evidence suggests neurodevelopmental disorders (NDs) may be associated with an increased incidence of concussion, but no studies have cross-sectionally and longitudinally assessed the associations of NDs and sex with concussion in collegiate athletes. We sought to assess the odds and relative risk (RR) of concussion in athletes self-reporting a diagnosis of attention deficit/hyperactivity disorder (ADHD), learning disability (LD), and ADHD+LD. Data from the Concussion Assessment, Research and Education (CARE) Consortium (2014-2017) were used to evaluate the likelihood of concussion for male and female athletes with ADHD, LD, and ADHD+LD, relative to controls. Odds ratios (ORs) of concussion history prior to enrollment and relative risk ratios for incurring a concussion following enrollment, with and without concussion history were calculated for all groups. Athletes with self-reported diagnosis of ADHD, LD, and ADHD+LD were more likely to report a single concussion (OR range = 1.528 to 1.828) and multiple concussions (OR range = 1.849 to 2.365) prior to enrollment in the CARE Consortium, irrespective of sex compared with control athletes. While enrolled in CARE, male athletes with ADHD, LD, and ADHD+LD had greater risk of incurring a concussion (RR range = 1.369 to 2.243) than controls, irrespective of concussion history. Male athletes with ADHD+LD with concussion history (RR = 2.221) and without concussion history (RR = 1.835) had greater risk of incurring a concussion than controls. These results suggest NDs may be associated with increased odds of single and multiple concussions, irrespective of sex. However, when we accounted for concussion history, it appears only male athletes with ADHD+LD had greater risk than respective controls. There were no significant differences between females and males with ADHD, LD, or ADHD+LD for either odds of concussion history or risk for incurring concussion.

Learning and Attention Deficit/Hyperactivity Disorders as Risk Factors for Prolonged Concussion Recovery in Children and Adolescents

OBJECTIVE

Examine pre-existing learning disorders (LD) and attention deficit/hyperactivity disorders (ADHD) as risk factors for prolonged recovery and increased symptomology following pediatric mild traumatic brain injury (mTBI).

METHODS

We conducted a retrospective cohort study of children/adolescents (5-17 years) with mTBI who presented to a Children's Minnesota Concussion Clinic between April 2018 and March 2019. Differences across strata of pre-existing conditions (present vs. absent) in time to recovery measures were estimated via Kaplan-Meier and Cox proportional hazards analyses and differences in symptom trajectories were examined via linear mixed-effects regression models. Regression models were adjusted for age, sex and other confounders.

RESULTS

In our cohort of 680 mTBI patients, those with LD (n = 70) or ADHD (n = 107) experienced significantly longer median durations of symptoms (58 and 68 days, respectively) than those without (43 days). Accordingly, LD was significantly associated with delayed symptom recovery (adjusted hazard ratio (aHR) = 1.63, 95% CI: 1.16-2.29), return to school (1.47, 1.08-2.00), and return to physical activity (1.50, 1.10-2.04). Likewise, ADHD was associated with delayed recovery (1.69, 1.28-2.23), return to school (1.52, 1.17-1.97) and physical activity (1.55, 1.19-2.01). Further, patients with LD or ADHD reported, on average, significantly more concussion symptoms and higher vision symptom scores throughout recovery versus those without. There was no evidence that concussion or vision symptom recovery trajectories varied over time between those with/without LD or ADHD (joint P-interactions > 0.05).

CONCLUSION

Pre-existing LD and ADHD are risk factors for prolonged and more symptomatic mTBI recovery in youth. These results can inform clinical concussion management and recovery expectations.

Repetitive Mild Traumatic Brain Injury in an Awake, Unanesthetized Mouse Model of Perinatal Nicotine Exposure Produces Transient Novelty-Seeking and Depression-Like Behaviors

Attention deficit hyperactivity disorder (ADHD) can be a risk factor for repetitive mild traumatic brain injury (mTBI) or concussions such as those that can occur in contact sports. Individuals with ADHD also appear to have a higher risk of poor neurocognitive outcomes after repetitive mTBI. Findings from clinical studies examining the interactions between ADHD and repetitive mTBI vary, likely because of variabilities in experimental design and outcome measures. We used a mouse model of perinatal nicotine exposure (PNE), which displays behavioral, neuroanatomical, and neurotransmitter features consistent with ADHD and subjected the mice to repetitive mTBI. We used a closed head model of mTBI in awake, unanesthetized mice to mimic concussions in humans. The mTBI was repeated three times daily for seven days. The mice in the PNE-mTBI group took longer to regain consciousness after the mTBI and showed transient novelty-seeking and depression-like behaviors. Before the repetitive mTBI, the mice in the PNE group showed attention deficit, which persisted after the mTBI. The mice in the control (non-PNE) group showed a transient attention deficit after the repetitive mTBI but not any of the other behavioral changes seen in the PNE-mTBI group. These findings from an unanesthetized mouse model with a pre-existing condition show that ADHD and repetitive mTBI together contribute to transient novelty-seeking and depression-like behavior supporting the notion that untreated ADHD may be a risk factor for poor neurocognitive outcomes after concussions.

Influence of Autism and Other Neurodevelopmental Disorders on Cognitive and Symptom Profiles: Considerations for Baseline Sport Concussion Assessment

OBJECTIVE

The presence of neurodevelopmental disorders (ND) such as attention-deficit/hyperactivity disorder (ADHD) and learning disorders (LD) have demonstrated effects on Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) performance. No current research has directly examined whether autism spectrum disorder (ASD) has similar effects. The current study compared ImPACT cognitive and symptom profiles in athletes with self-reported ASD to other NDs and healthy controls using case-control matching.

METHOD

The current study compared ImPACT baselines of high school athletes with ASD to athletes with other NDs (ADHD, LD, and co-occurring ADHD/LD) and healthy controls on cognitive composites and symptom reporting. Participants included 435 athletes (87 controls, 87 with ASD, 87 with ADHD, 87 with LD, and 87 with ADHD/LD) selected from a larger naturalistic sample. Athletes were matched to the ASD group based on age, sex, and sport using randomized case-matched selection from the larger database.

RESULTS

Results revealed that athletes with ASD performed more poorly than healthy controls on the Visual Motor Speed composite. No differences were found for Post-concussion Symptom Scale (PCSS) domain scores. Differences in cognitive and symptom profiles among the athletes with other NDs were also found.

CONCLUSIONS

Results elucidate patterns of baseline performance for athletes with ASD, demonstrating that there may not be significant differences between ASD and healthy controls on four of the five ImPACT composites, and no symptom reporting differences. Cognitive and symptom differences found for other NDs should be considered when interpreting baseline performance and for making return-to-play decisions in the absence of baseline assessment.

Attention-Deficit/Hyperactivity Disorder Status and Sex Moderate Mild Traumatic Brain Injury Symptom Severity in Children and Adolescents: Implications for Clinical Management

OBJECTIVE

To investigate the impact of pediatric mild traumatic brain injury (mTBI), using a broad parent-reported measure, and to determine whether parent-ratings of mTBI symptoms are higher among those with premorbid attention-deficit/hyperactivity disorder (ADHD) and females.

DESIGN

Retrospective case-control.

SETTING

Hospital-based sports medicine clinic.

PARTICIPANTS

The retrospective chart review included 1346 (age: M = 13.11 years, SD = 2.6; 61.7% male) pediatric patients with (n = 209) and without (n = 1137) ADHD.

INDEPENDENT VARIABLES

Group membership (ADHD vs non-ADHD) and sex (male vs female).

MAIN OUTCOME MEASURES

Baseline and current Post-Concussion Symptom Inventory-Parent Report Form (PCSI-P) Physical, Emotional, Cognitive, and Fatigue subscale scores. This study used a retrospective chart review; therefore, the hypotheses reported for the current study were formed after data were collected.

RESULTS

Controlling for patient age and days from mTBI, patients with ADHD had significantly higher retrospective parent-reported pre-mTBI ratings of physical, emotional, and cognitive symptoms (ds = 0.17-0.62) and higher post-mTBI ratings across all 4 symptom domains (ds = 0.18-0.57) than those without ADHD. There was no group × time interaction for any of the PCSI-P subscales. Females overall had higher retrospective parent-reported pre-injury Fatigue and Emotional symptoms (ds = 0.13-0.19) and higher post-mTBI symptoms in all 4 PCSI-P symptom domains (ds = 0.23-0.35), relative to males.

CONCLUSIONS

Attention-deficit/hyperactivity disorder-related postinjury exacerbations in parent-reported symptoms can be explained, in part, by elevated retrospective parent-reported ADHD-related pre-mTBI ratings. These results highlight the importance of assessing a patient's baseline symptoms post-mTBI. These data also indicate that ADHD status and sex should be considered when interpreting mTBI symptom severity during clinical evaluation of concussion.

Multiple Past Concussions in High School Hockey Players: Examining Cognitive Functioning and Symptom Reporting

OBJECTIVE

To investigate (1) if there are meaningful differences in baseline preseason cognitive functioning or symptom reporting between high school ice hockey players with and without prior concussions and (2) determine which health history variables predict symptom reporting.

DESIGN

Cross-sectional study.

SETTING

High schools across the state of Maine.

PARTICIPANTS

Participants were 1616 male high school ice hockey players (mean age = 15.6 years; SD = 1.5 years) who completed baseline testing between 2009 and 2015.

INDEPENDENT VARIABLES

Athletes were grouped according to their self-reported concussion history [0 (n = 1136), 1 (n = 321), 2 (n = 112), or 3+ (n = 47) previous concussions].

MAIN OUTCOME MEASURES

Cognitive functioning was measured by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery, and symptom ratings were obtained from the Post-Concussion Symptom Scale.

RESULTS

There were no statistically significant differences between groups in cognitive functioning as measured by ImPACT. The group with ≥3 prior concussions endorsed higher total symptom scores, but the effect sizes were small and not statistically significant. In a multivariate model, prior treatment for headaches (not necessarily migraines), prior treatment for a psychiatric condition, and prior treatment for substance/alcohol use all significantly predicted total symptom scores, with concussion history being the weakest independent predictor.

CONCLUSIONS

Players with a history of prior concussions performed similarly to players with no prior concussions on cognitive testing. Health history factors were more strongly associated with symptom reporting than concussion history.

Using a Likelihood Heuristic to Summarize Conflicting Literature on Predictors of Clinical Outcome Following Sport-Related Concussion

OBJECTIVE

To introduce a new methodology for summarizing the results from systematic reviews-a likelihood heuristic-to the field of sport-related concussion.

DATA SOURCES

We applied the likelihood heuristic to the results of a systematic review published by Iverson et al (2017), containing 101 studies, on the predictors of worse clinical outcome following sport-related concussion.

STUDY SELECTION

We re-examined 5 individual prognostic factors that are of clinical interest and for which there is conflicting literature (female sex = 44 studies, prior concussion history = 41 studies, loss of consciousness = 31 studies, post-traumatic amnesia = 25 studies, and retrograde amnesia = 10 studies).

DATA EXTRACTION

For each prognostic factor, likelihood ratios were generated using the (1) number of significant and nonsignificant studies, (2) study power, (3) alpha level, and (4) prior probability that the alternative hypothesis was true.

DATA SYNTHESIS

Assuming each study had 80% power and an alpha level of 5%, observing the reported number of conflicting studies for female sex, prior concussion history, and retrograde amnesia is substantially more likely if each prognostic factor is associated with worse clinical outcome following sport-related concussion. For loss of consciousness, the observed number of conflicting studies is more likely if loss of consciousness is not associated with worse clinical outcome following sport-related concussion. A secondary analysis incorporating potentially more realistic study parameters of statistical power (45%) and alpha level (25%) generates weaker likelihood evidence that the observed numbers of studies for each prognostic factor are associated with worse clinical outcome following sport-related concussion than they are not.

CONCLUSIONS

Using a likelihood heuristic with 80% power and 5% alpha level, there is very strong likelihood evidence that female sex, prior concussion history, and retrograde amnesia are associated with worse clinical outcome following sport-related concussion. The strength of likelihood evidence that prognostic factors are associated with worse clinical outcome reduces when statistical power is lower and alpha level is inflated.

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.

Severity of Ongoing Post-Concussive Symptoms as a Predictor of Cognitive Performance Following a Pediatric Mild Traumatic Brain Injury

OBJECTIVE

This study aimed to examine the predictors of cognitive performance in patients with pediatric mild traumatic brain injury (pmTBI) and to determine whether group differences in cognitive performance on a computerized test battery could be observed between pmTBI patients and healthy controls (HC) in the sub-acute (SA) and the early chronic (EC) phases of injury.

METHOD

203 pmTBI patients recruited from emergency settings and 159 age- and sex-matched HC aged 8-18 rated their ongoing post-concussive symptoms (PCS) on the Post-Concussion Symptom Inventory and completed the Cogstate brief battery in the SA (1-11 days) phase of injury. A subset (156 pmTBI patients; 144 HC) completed testing in the EC (~4 months) phase.

RESULTS

Within the SA phase, a group difference was only observed for the visual learning task (One-Card Learning), with pmTBI patients being less accurate relative to HC. Follow-up analyses indicated higher ongoing PCS and higher 5P clinical risk scores were significant predictors of lower One-Card Learning accuracy within SA phase, while premorbid variables (estimates of intellectual functioning, parental education, and presence of learning disabilities or attention-deficit/hyperactivity disorder) were not.

CONCLUSIONS

The absence of group differences at EC phase is supportive of cognitive recovery by 4 months post-injury. While the severity of ongoing PCS and the 5P score were better overall predictors of cognitive performance on the Cogstate at SA relative to premorbid variables, the full regression model explained only 4.1% of the variance, highlighting the need for future work on predictors of cognitive outcomes.

Stimulant Therapy Utilization for Neurocognitive Deficits in Mild Traumatic Brain Injury

CONTEXT

There are 3.8 million mild traumatic brain injuries (mTBIs) that occur each year in the United States. Many are left with prolonged life-altering neurocognitive deficits, including difficulties in attention, concentration, mental fatigue, and distractibility. With extensive data on the safety and efficacy of stimulant medications in treating attention deficit, concentration difficulties and distractibility seen with attention deficit disorder, it is not surprising that interest continues regarding the application of stimulant medications for the persistent neurocognitive deficits in some mTBIs.

EVIDENCE ACQUISITION

Studies were extracted from PubMed based on the topics of neurocognitive impairment, mTBI, stimulant use in mTBI, stimulants, and the association between attention deficit/hyperactivity disorder and mTBI. The search criteria included a date range of 1999 to 2020 in the English language.

STUDY DESIGN

Literature review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Currently, there is very limited literature, and no guidelines for evaluating the use of stimulant medication for the treatment of prolonged neurocognitive impairments due to mTBI. However, a limited number of studies have demonstrated efficacy and safety of stimulants in the treatment of neurocognitive sequelae of mTBI in the adult, pediatric, military, and athletic populations.

CONCLUSION

There is limited evidence to suggest stimulant medication may be beneficial in patients with mTBI with persistent neurocognitive symtpoms. The decision to utilize stimulant medication for mTBI patients remains physician and patient preference dependent. Given the limited encouraging data currently available, physicians may consider stimulant medication in appropriate patients to facilitate the recovery of prolonged neurocognitive deficits, while remaining cognizant of potential adverse effects.

The Association between Baseline Eye Tracking Performance and Concussion Assessments in High School Football Players

SIGNIFICANCE

Concussions are complex injuries that require a multifaceted testing battery. Vision impairments are common after concussion, but it is unknown exactly how eye tracking may be affected after injury and how it is associated with other clinical concussion assessments.

PURPOSE

This study aimed to (1) examine the relationship between eye tracking performance (BOX score) and other common concussion evaluations, (2) identify if eye tracking adds novel information that augments baseline concussion evaluations, and (3) examine the effect of age, concussion history, and attention-deficit/hyperactivity disorder on eye tracking and other ophthalmological measures.

METHODS

A total of 102 male high school football athletes (age, 16.0 years; 95% confidence interval, 15.8 to 16.2 years) completed a series of visual and neurocognitive tests during their pre-season baseline assessment. The main outcome measures were BOX score, near point of convergence (NPC) distance, binocular accommodative amplitude (BAA) distance, Standardized Assessment of Concussion score, and Immediate Post-Concussion Assessment and Cognitive Testing composite scores.

RESULTS

BOX score was not significantly associated with symptoms, Standardized Assessment of Concussion score, NPC distance, BAA distance, or any Immediate Post-Concussion Assessment and Cognitive Testing composite scores. Age, concussion history, attention-deficit/hyperactivity disorder, and number of prior years playing football were not significantly associated with BOX score or NPC distance, but there was a significant association between concussion history and greater BAA distance (β = 1.60; 95% confidence interval = 0.19 to 3.01; P < .03). The BOX score cutoff of 10 resulted in a 12% false-positive rate.

CONCLUSIONS

Eye tracking was not significantly associated with the commonly used clinical concussion assessments. These results suggest that an objective eye tracking variable may be a valuable addition to the current concussion battery.

Preinjury and Postinjury Factors That Predict Sports-Related Concussion and Clinical Recovery Time

OBJECTIVES

To evaluate the relationship between preinjury risk factors (RFs) and subsequent occurrence of concussion and examine whether preinjury RFs or postinjury assessments predict clinical recovery in collegiate athletes.

METHODS

Risk factors (sex, sport, and self-report history of concussion, migraine, attention-deficit disorder, learning disability, depression, and anxiety) and Sport Concussion Assessment Tool (SCAT), depression/anxiety screenings, and neuropsychological testing were obtained before the season. For athletes who sustained concussion, RFs, postinjury SCAT, neuropsychological assessment, and clinical recovery were assessed.

RESULTS

We assessed 1152 athletes (69% male) at baseline and 145 (75% male) after subsequent concussion diagnosis. Only sport type (Wald = 40.29, P = 0.007) and concussion history (Wald = 9.91, P = 0.007) accounted for unique variance in subsequent concussion. Of athletes followed until full recovery, mean days until symptom-free (DUSF) was 9.84 ± 11.11 days (n = 138, median = 5 days, range = 1-86) and mean days until full return to play (DUFRTP) was 20.21 ± 19.17 (n = 98, median = 20.21, range = 4-150). None of the RFs or baseline testing measures were associated with DUSF or DUFRTP (P's > 0.05). After injury, athletes who reported more total symptoms (rs = 0.31, P < 0.001) and higher symptom severity (rs = 0.33, P < 0.001) exhibited longer DUSF. Days until symptom-free correlated with DUFRTP (rs = 0.75, P < 0.001). Among athletes assessed within 2 days after injury, DUSF was associated with Immediate Postconcussion Assessment and Cognitive Test visual motor (rs = -0.31, P = 0.004), reaction time (rs = 0.40, P < 0.001), and symptom score (rs = 0.54, P < 0.001).

CONCLUSIONS

Only sport type and concussion history predicted subsequent occurrence of concussion, and none of the RFs or baseline measures predicted clinical recovery. Immediate postinjury assessments, including symptom number and severity, and select clinical measures predicted longer clinical recovery.

Association between premorbid neuropsychological conditions and pediatric mild traumatic brain injury/concussion recovery time and symptom severity: a systematic review

OBJECTIVE

The objective of this review was to identify associations between premorbid neuropsychological conditions and pediatric mild traumatic brain injury/concussion recovery time and symptom severity.

INTRODUCTION

There is a lack of evidence-based clinical guidelines for the care of children with a premorbid neuropsychological condition who have sustained a mild traumatic brain injury, also known as concussion. This necessitates inquiry for any associations that may exist, which may contribute to an enhanced understanding of injury recovery patterns.

INCLUSION CRITERIA

Participants included children ages six through 18 years with any diagnosed or self-reported premorbid neuropsychological condition(s) and mild traumatic brain injury/concussion. Participants with concomitant intracranial or extra-axial head injury found on diagnostic imaging were excluded. Outcomes for this review included recovery time or symptom(s) severity post-concussion. Studies considered for review were analytical observational studies, including retrospective, prospective, cross-sectional or longitudinal cohort studies or case-control studies, as well as descriptive observational study designs, including case series, individual case reports and descriptive cross-sectional studies.

METHODS

A comprehensive search was undertaken in January 2018 for both published and unpublished studies utilizing an a priori protocol. Major databases searched included CINAHL, Embase, PubMed, Psychology and Behavioral Sciences Collection and PsycINFO. Other sources searched for unpublished and gray literature included the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Google Scholar, ProQuest Dissertations and Theses Global: Sciences and Engineering Collection and MedNar. Additional searches of government websites and reports targeting healthcare or sports-related concussions included Australian Sports Commission, Canadian Institutes for Health Research, the National Health Service of the United Kingdom, the U.S. Department of Health and Human Services: Agency for Healthcare Research and Quality, and the U.S. Department of Health and Human Services: Centers for Disease Control and Prevention. Critical appraisal and data extraction were completed by two independent reviewers. Validation of methodologic quality was performed utilizing standardized tools from the Joanna Briggs Institute, and any disputes were resolved through discussion. Due to significant heterogeneity among studies, a meta-analysis could not be conducted. Therefore, extracted data are reported in a narrative synthesis.

RESULTS

A total of 12 studies (one analytical cross-sectional, two case-control and nine cohort) with 2,973 participants met inclusion criteria. Results of the findings among premorbid conditions varied. However, statistically significant associations with prolonged recovery or increased symptom severity were identified in children with pre-concussion histories of learning disabilities or poor academic achievement; anxiety, depression, mood disorders or other psychiatric illnesses; prior head injuries; somatization (in females); sleep disorders (in males); and the presence of multiple neuropsychological conditions.

CONCLUSIONS

Due to heterogeneity among studies and limitations of the review, findings suggest that clinicians providing post-concussive care may consider the presence of premorbid neuropsychological conditions, specifically learning disabilities or poor academic achievement; anxiety, depression, mood disorders or other psychiatric illnesses; prior head injuries; somatization; sleep disorders; or the presence of multiple neuropsychological conditions as potential contributors to prolonged recovery times or increased symptom severity in children and adolescents with mild traumatic brain injuries.

Attention-Deficit/Hyperactivity Disorder and Outcome After Concussion: A Systematic Review

OBJECTIVE

To synthesize the literature and conduct a gap analysis on the association between attention-deficit/hyperactivity disorder (ADHD) and clinical outcome from sport-related concussion.

METHOD

The electronic search for this systematic review (PROSPERO ID: CRD42019128281) was conducted in February 2019 using terms related to concussion, sports/athletics, and predictors/modifiers of outcome to search the PubMed, PsycINFO, MEDLINE, CINAHL, Cochrane Library, EMBASE, SPORTDiscus, Scopus, and Web of Science databases. Eligible studies evaluated the association between ADHD and outcome from sport-related concussion. Of 4014 studies screened, 359 full-text articles were reviewed, with 14 studies ultimately included, involving 3623 participants (n = 359 [9.9%] with ADHD).

RESULTS

Study samples were primarily from specialty medical clinics (57.1%) and high school or college athletic groups (28.6%). Only 2 studies reported a statistically significant association between ADHD and worse clinical outcome. Of these, 1 included 13 participants with ADHD and the other included only 8 participants with ADHD. Only 1 previous study in this review was designed specifically to examine ADHD and prolonged concussion recovery, and that study did not report a statistically significant association.

CONCLUSION

There is not a clear association between ADHD and worse clinical outcome from concussion. However, eligible studies had limitations in research design, and nearly all studies were underpowered and evaluated the association between ADHD and concussion outcome as a secondary focus rather than the primary research question, precluding definitive conclusions. The association between ADHD and clinical outcomes remains unclear, and future research specifically examining ADHD and concussion recovery is needed.

Reliability of Objective Eye-Tracking Measures Among Healthy Adolescent Athletes

OBJECTIVE

To determine the test-retest correlation of an objective eye-tracking device among uninjured youth athletes.

DESIGN

Repeated-measures study.

SETTING

Sports-medicine clinic.

PARTICIPANTS

Healthy youth athletes (mean age = 14.6 ± 2.2 years; 39% women) completed a brief, automated, and objective eye-tracking assessment.

INDEPENDENT VARIABLES

Participants completed the eye-tracking assessment at 2 different testing sessions.

MAIN OUTCOME MEASURES

During the assessment, participants watched a 220-second video clip while it moved around a computer monitor in a clockwise direction as an eye tracker recorded eye movements. We obtained 13 eye movement outcome variables and assessed correlations between the assessments made at the 2 time points using Spearman's Rho (rs).

RESULTS

Thirty-one participants completed the eye-tracking evaluation at 2 time points [median = 7 (interquartile range = 6-9) days between tests]. No significant differences in outcomes were found between the 2 testing times. Several eye movement variables demonstrated moderate to moderately high test-retest reliability. Combined eye conjugacy metric (BOX score, rs = 0.529, P = 0.008), the variance of the ratio for both eye movements in the horizontal (rs = 0.497, P = 0.013) and vertical (rs = 0.446; P = 0.029) movement planes along the top/bottom of the computer screen, and the variance of the left and right eye movement along the bottom segment of the computer screen (rs = 0.565; P = 0.004) each demonstrated moderate between-test correlations.

CONCLUSIONS

Automated and quantitative eye movement and conjugacy metrics provide relatively stable measurements among a group of healthy youth athletes. Thus, their inclusion as a visual tracking metric may be complementary to other visual examination techniques when monitoring concussion recovery across time.

Adolescents With ADHD Do Not Take Longer to Recover From Concussion

The objective of this study was to determine whether adolescents with attention-deficit/hyperactivity disorder (ADHD) have prolonged return to school and sports following concussion compared to those without ADHD and whether medication status or concussion history is associated with recovery time. We hypothesized that having ADHD would not be associated with longer recovery time. This prospective observational cohort study, conducted between 2014 and 2019, examined concussion recovery among school sponsored athletics throughout Maine, USA. The sample included 623 adolescents, aged 14-19 years (mean = 16.3, standard deviation = 1.3 years), 43.8% girls, and 90 (14.4%) reported having ADHD. Concussions were identified by certified athletic trainers. We computed days to return to school (full time without accommodations) and days to return to sports (completed return to play protocol) following concussion. Adolescents with ADHD [median days = 7, interquartile range (IQR) = 3-13, range = 0-45] did not take longer than those without ADHD (median days = 7, IQR = 3-13, range = 0-231) to return to school (U = 22,642.0, p = 0.81, r = 0.01; log rank: χ 1 2 = 0.059, p = 0.81). Adolescents with ADHD (median days = 14, IQR = 10-20, range = 2-80) did not take longer than those without ADHD (median days = 15, IQR = 10-21, range = 1-210) to return to sports (U = 20,295.0, p = 0.38, r = 0.04; log rank: χ 1 2 = 0.511, p = 0.48). Medication status and concussion history were not associated with longer recovery times. Adolescents with ADHD did not take longer to functionally recover following concussion. Recovery times did not differ based on whether adolescents with ADHD reported taking medication to treat their ADHD or whether they reported a prior history of concussion.

Effects of attention deficit hyperactivity disorder and learning disability on vestibular and ocular baseline concussion assessment in pediatric athletes

Vestibular and ocular motor assessment has gained popularity as a tool for sport-related concussion among healthcare professionals. With awareness of premorbid risk factors, such as attentional problems, it is imperative to understand their effects at baseline. The purpose of this study was to examine the effects of attention deficit/hyperactivity disorder (ADHD) and diagnosed learning disability (LD) on vestibular and oculomotor baseline concussion assessment in pediatrics. Pediatric athletes between the ages of 8 and 14 years with ADHD/LD (n = 30) and match controls without ADHD/LD (n = 30) completed baseline concussion testing, consisting of symptom provocation on the Vestibular/Ocular Motor Screening (VOMS) and oculomotor performance on near point of convergence (NPC) and King-Devick (K-D) tools. Those diagnosed with ADHD/LD performed worse on baseline saccades (p range = .02-.10), convergence (p = .04), vestibular ocular reflex (VOR) (p = .03) and visual motion sensitivity (VMS) (p = .04) of the VOMS. Base rate analyses revealed that 26% of athletes in the ADHD/LD group had ≥1 and 13.3% had ≥2 VOMS domains over clinical cutoff levels, compared to 3.3% (≥1 domain) and 0 (≥2 domains) of controls. Individuals with ADHD/LD also performed worse on K-D assessment (p = .005). However, no differences were reported on NPC distance (p = .19). These findings suggest worse baseline concussion assessment scores on vestibular/ocular motor assessment domains in pediatric athletes diagnosed with ADHD/LD. Additional research is needed on assessment outcomes to determine if special consideration to those diagnosed with ADHD/LD is warranted.

Risk of Repeat Concussion Among Patients Diagnosed at a Pediatric Care Network

OBJECTIVE

To quantify the risk of repeat concussions for children and identify demographic and clinical aspects of the index concussion associated with repeat injury.

STUDY DESIGN

For this retrospective cohort study, we queried the Children's Hospital of Philadelphia healthcare network's unified electronic health record to identify all 5- to 15-year-old patients who had their first clinical visit for an index concussion at a Children's Hospital of Philadelphia location from July 2012 through June 2013. A 25% random sample (n = 536) were selected. Clinical data were abstracted for their index concussion and all concussion-related visits for 2 years following the index concussion.

RESULTS

Overall, 16.2% (n = 87) of patients experienced at least 1 repeat concussion within 2 years of their index concussion. The risk of repeat concussion increased with patient age (9.5% for ages 5-8 years; 10.7% for ages 9-11 years; and 19.8% for ages 12-15 years). After we adjusted for other factors, risk was particularly heightened among patients whose index concussion had a longer clinical course (>30 vs 0-7 days, adjusted risk ratio 1.65 [1.01-2.69]) and greater symptom burden (>11 vs 0-2 symptoms, adjusted risk ratio 2.12 [1.12-3.72]).

CONCLUSIONS

We estimate that 1 in 6 youth diagnosed with a concussion are diagnosed with a subsequent concussion within 2 years and that several clinical characteristics of the index concussion increase this risk. Identifying factors associated with a repeat injury is essential to inform the clinical management of concussion and direct injury prevention efforts.

Sport-Related Concussion: Evaluation, Treatment, and Future Directions

Sport-related concussion (SRC) is a highly prevalent injury predominantly affecting millions of youth through high school athletes every year. In recent years, SRC has received a significant amount of attention due to potential for long-term neurologic sequelae. However, the acute symptoms and possibility of prolonged recovery account for the vast majority of morbidity from SRC. Modifying factors have been identified and may allow for improved prediction of a protracted course. Potential novel modifying factors may include genetic determinants of recovery, as well as radiographic biomarkers, which represent burgeoning subfields in SRC research. Helmet design and understanding the biomechanical stressors on the brain that lead to concussion also represent active areas of research. This narrative review provides a general synopsis of SRC, including relevant definitions, current treatment paradigms, and modifying factors for recovery, in addition to novel areas of research and future directions for SRC research.

Prognostic Factors in Pediatric Sport-Related Concussion

PURPOSE OF REVIEW

Sport-related concussion (SRC) and mild traumatic brain injury (mTBI) have been thrust into the national spotlight, with youth athletes bearing the burden of this public health problem. The current review aims to provide a practical summary of pediatric SRC, including key terminology, return to play/school, and risk factors for post-concussion syndrome (PCS).

RECENT FINDINGS

While the majority of youth athletes recover within 2 to 4 weeks, approximately 10% of athletes experience a protracted recovery with symptoms lasting months, impacting social, scholastic, and sporting activities. In the pediatric population, the strongest predictors of PCS are initial symptom burden and prior concussion, with mixed results behind the factors of gender, headaches, and learning disability. The role of psychiatric, family history, sports, and socioeconomic factors remain in their infancy.

A systematic review of criteria used to define recovery from sport-related concussion in youth athletes

OBJECTIVE

The Concussion in Sport Group guidelines recommend a multifaceted approach to help clinicians make return to sport decisions. The purpose of this study was to identify the most common multifaceted measures used to define clinical recovery from sport-related concussion in young athletes (high school and/or college level) and to summarise existing knowledge of criteria used to make return to sport decisions.

DESIGN

Systematic review.

DATA SOURCES

The PubMed (MEDLINE), SPORTDiscus and Embase electronic databases were searched from 1 January 2000 to 1 March 2017 by three independent reviewers.

ELIGIBILITY CRITERIA

Inclusion criteria: elementary, high school and college age groups, and a specific definition of clinical recovery that required two or more measures.

EXCLUSION CRITERIA

review articles, articles using the same sample population, case studies, non-English language and those that used one measure only or did not specify the recovery measures used.

STUDY QUALITY

Study quality was assessed using the Downs and Black Criteria.

RESULTS

Of 2023 publications, 43 met inclusion criteria. Included articles reported the following measures of recovery: somatic symptom resolution or return to baseline (100%), cognitive recovery or return to baseline (86%), no exacerbation of symptoms on physical exertion (49%), normalisation of balance (30%), normal special physical examination (12%), successful return to school (5%), no exacerbation of symptoms with cognitive exertion (2%) and normalisation of cerebral blood flow (2%). Follow-up to validate the return to sport decision was reported in eight (19%) articles. Most studies were case-control or cohort (level of evidence 4) and had significant risk of bias.

CONCLUSION

All studies of sport-related concussion use symptom reports to define recovery. A minority of studies used multiple measures of outcome or had clearly defined recovery criteria, the most common being a combination of a self-reported symptom checklist and a computerised neurocognitive test. Future studies ideally should define recovery a priori using objective physiological measures in addition to symptom reports.

Neurocognitive Deficits Associated With ADHD in Athletes: A Systematic Review

Context:

Attention deficit hyperactivity disorder (ADHD) is a common childhood disorder and is frequently diagnosed in young adults. Emerging studies suggest a relationship between ADHD and concussion.

Objective:

To determine whether athletes with ADHD are at increased risk for neurocognitive deficits related to concussion risk, symptom reporting, and recovery.

Data Sources:

A comprehensive search of PubMed, CINAHL, PsychInfo, and Cochrane Library databases was performed. Studies conducted between 2006 and 2017 were reviewed, although only those between 2013 and 2017 met inclusion criteria.

Study Selection:

Studies that examined neurocognitive deficits in adolescent and young adult athletes aged 15 to 19 years who had ADHD and reported using notable neuropsychological evaluation tools were included.

Study Design:

Systematic review.

Level of Evidence:

Level 2.

Results:

A total of 17 studies met the inclusion criteria. The prevalence of ADHD in athletes varied between 4.2% and 8.1%. Overall, athletes with ADHD demonstrated lower scores on neurocognitive testing such as the ImPACT (Immediate Post-Concussion Assessment and Cognitive Test), increased risk for concussion, and increased symptom reporting. There was no evidence that treatment with stimulant medication changed these risks.

Conclusion:

ADHD is associated with increased neurocognitive deficits in athletes, although pathophysiology remains unclear. Evidence for stimulant treatment in athletes with ADHD continues to be sparse.

Attention Deficit Hyperactivity Disorder: Unique Considerations in Athletes

Context:

Attention deficit hyperactivity disorder (ADHD) is a common psychiatric condition in the general population, with evidence suggesting that it may be more common among athletes.

Evidence Acquisition:

Literature searches were performed on PubMed, MEDLINE, and Cochrane databases for the years 2000 to 2016 utilizing the following key search terms: ADHD, ADD, guidelines, diagnosis, athlete, sports, treatment, pharmacotherapy, stimulants, risk, cardiovascular effects, concussion, and traumatic brain injury (TBI).

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

ADHD exists among athletes at all levels of play, and symptomatology overlaps significantly with that of concussion. Treatment with stimulants has cardiovascular effects and may not be permitted by the athlete’s governing body. An athlete’s level of competition and individual cardiovascular risk factors may therefore affect medication choices.

Conclusion:

ADHD diagnosis and treatment are paramount to optimal quality of life and functioning in affected individuals. Pharmacologic treatment options should not specifically be avoided in athletes; however, stimulant use is an independent risk factor for heat illness. Concussion, a common athletic injury, may have an altered course in those affected by ADHD, specifically with regard to neurocognitive testing and recovery.

Predictors of clinical recovery from concussion: a systematic review

OBJECTIVE

A systematic review of factors that might be associated with, or influence, clinical recovery from sport-related concussion. Clinical recovery was defined functionally as a return to normal activities, including school and sports, following injury.

DESIGN

Systematic review.

DATA SOURCES

PubMed, PsycINFO, MEDLINE, CINAHL, Cochrane Library, EMBASE, SPORTDiscus, Scopus and Web of Science.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies published by June of 2016 that addressed clinical recovery from concussion.

RESULTS

A total of 7617 articles were identified using the search strategy, and 101 articles were included. There are major methodological differences across the studies. Many different clinical outcomes were measured, such as symptoms, cognition, balance, return to school and return to sports, although symptom outcomes were the most frequently measured. The most consistent predictor of slower recovery from concussion is the severity of a person's acute and subacute symptoms. The development of subacute problems with headaches or depression is likely a risk factor for persistent symptoms lasting greater than a month. Those with a preinjury history of mental health problems appear to be at greater risk for having persistent symptoms. Those with attention deficit hyperactivity disorder (ADHD) or learning disabilities do not appear to be at substantially greater risk. There is some evidence that the teenage years, particularly high school, might be the most vulnerable time period for having persistent symptoms-with greater risk for girls than boys.

CONCLUSION

The literature on clinical recovery from sport-related concussion has grown dramatically, is mostly mixed, but some factors have emerged as being related to outcome.

Potential factors influencing recovery from concussion in collegiate student-athletes

Background

Factors including sex, previous diagnosis of migraines, previous diagnosis of Attention Deficit Disorder/Attention Deficit Hyperactivity Disorder, and a history of concussion may influence the length of recovery from concussion in collegiate student-athletes.

Purpose

To better understand factors that may influence recovery from concussion in collegiate-student athletes.

Methods

A total of 91 student-athletes from a Division I NCAA University who sustained concussions from the fall of 2011 to the spring of 2015 were evaluated. They were considered recovered from their concussion when neurocognitive and symptom scores returned to baseline and they were cleared by their physician. Analyses of variance were conducted to determine if potential factors influenced concussion recovery ( p < .0125).

Results

No significant differences were found for sex (males = 7.4 ± 5.9; females = 8.3 ± 4.8 days; p = 0.417), previous diagnosis of migraines (diagnosis = 8.0 ± 5.7; no diagnosis = 7.8 ± 5.4 days; p = 0.926), or history of concussion (history = 8.3 ± 5.7; no history = 5.6 ± 3.4 days; p = 0.088). However, a significant difference in the length of recovery was found between those with a previous diagnosis of Attention Deficit Disorder/Attention Deficit Hyperactivity Disorder and those without (diagnosis = 13.3 ± 7.3; no diagnosis = 7.3 ± 4.9 days; p = 0.002).

Conclusion

Student-athletes with Attention Deficit Disorder/Attention Deficit Hyperactivity Disorder show significantly longer recovery from concussions than those without. Further investigation of this and other factors that influence recovery from concussion may help in concussion recovery and return-to-play guidelines that improve student-athlete well-being.

What is the difference in concussion management in children as compared with adults? A systematic review

AIM

To evaluate the evidence regarding the management of sport-related concussion (SRC) in children and adolescents. The eight subquestions included the effects of age on symptoms and outcome, normal and prolonged duration, the role of computerised neuropsychological tests (CNTs), the role of rest, and strategies for return to school and return to sport (RTSp).

DESIGN

Systematic review.

DATA SOURCES

MEDLINE (OVID), Embase (OVID) and PsycInfo (OVID).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included if they were original research on SRC in children aged 5 years to 18 years, and excluded if they were review articles, or did not focus on childhood SRC.

RESULTS

A total of 5853 articles were identified, and 134 articles met the inclusion criteria. Some articles were common to multiple subquestions. Very few studies examined SRC in young children, aged 5-12 years.

SUMMARY/CONCLUSIONS

This systematic review recommends that in children: child and adolescent age-specific paradigms should be applied; child-validated symptom rating scales should be used; the widespread routine use of baseline CNT is not recommended; the expected duration of symptoms associated with SRC is less than 4 weeks; prolonged recovery be defined as symptomatic for greater than 4 weeks; a brief period of cognitive and physical rest should be followed with gradual symptom-limited physical and cognitive activity; all schools be encouraged to have a concussion policy and should offer appropriate academic accommodations and support to students recovering from SRC; and children and adolescents should not RTSp until they have successfully returned to school, however early introduction of symptom-limited physical activity is appropriate.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2016:CRD42016039184.

Comparison of baseline and post-concussion ImPACT test scores in young athletes with stimulant-treated and untreated ADHD

OBJECTIVES

Baseline and post-concussion neurocognitive testing is useful in managing concussed athletes. Attention deficit hyperactivity disorder (ADHD) and stimulant medications are recognized as potential modifiers of performance on neurocognitive testing by the Concussion in Sport Group. Our goal was to assess whether individuals with ADHD perform differently on post-concussion testing and if this difference is related to the use of stimulants.

METHODS

Retrospective case-control study in which 4373 athletes underwent baseline and post-concussion testing using the ImPACT battery. 277 athletes self-reported a history of ADHD, of which, 206 reported no stimulant treatment and 69 reported stimulant treatment. Each group was matched with participants reporting no history of ADHD or stimulant use on several biopsychosocial characteristics. Non-parametric tests were used to assess ImPACT composite score differences between groups.

RESULTS

Participants with ADHD had worse verbal memory, visual memory, visual motor speed, and reaction time scores than matched controls at baseline and post-concussion, all with p ≤ .001 and |r|≥ 0.100. Athletes without stimulant treatment had lower verbal memory, visual memory, visual motor speed, and reaction time scores than controls at baseline (p ≤ 0.01, |r|≥ 0.100 [except verbal memory, r = -0.088]) and post-concussion (p = 0.000, |r|> 0.100). Athletes with stimulant treatment had lower verbal memory (Baseline: p = 0.047, r = -0.108; Post-concussion: p = 0.023, r = -0.124) and visual memory scores (Baseline: p = 0.013, r = -0.134; Post-concussion: p = 0.003, r = -0.162) but equivalent visual motor speed and reaction time scores versus controls at baseline and post-concussion.

CONCLUSIONS

ADHD-specific baseline and post-concussion neuropsychological profiles, as well as stimulant medication status, may need to be considered when interpreting ImPACT test results. Further investigation into the effects of ADHD and stimulant use on recovery from sport-related concussion (SRC) is warranted.

Evidence-Based Considerations and Recommendations for Athletic Trainers Caring for Patients With Attention-Deficit/Hyperactivity Disorder

CONTEXT

Patients with attention-deficit/hyperactivity disorder (ADHD) can be noncompliant, impulsive, and disruptive in an athletic training or physical rehabilitation facility. Athletic trainers (ATs) are valuable and essential health care providers for active patients with ADHD. However, for a patient with ADHD to have a successful outcome in a busy athletic training environment, the AT or health care provider must tailor the treatment setting to the patient's needs.

OBJECTIVE

To educate and raise awareness among ATs about patients with ADHD and to provide ATs with strategies and tools that will allow them to treat patients with ADHD more effectively.

DATA SOURCES

We retrieved and reviewed articles from PubMed, PsychINFO, and Ovid without date restrictions. Search words were attention deficit hyperactivity disorder plus 1 of the following topics or search words: athletic training, athletics, coaching, sport, or sport psychology.

STUDY SELECTION

Any ADHD articles that were not applicable or translatable in good faith to athletic training, physical rehabilitation, or sport and exercise were excluded.

DATA EXTRACTION

Nonpharmacologic interventions were reviewed and amassed into categories from which the recommendations were created. No statistical analyses were conducted for this review.

DATA SYNTHESIS

We identified 1241 articles, and 86 met the inclusion criteria. Five groups of evidence were observed: (1) goal setting and coaching, (2) reinforcements and outcomes, (3) routines and treatment timing, (4) simplified feedback and instructions, and (5) environmental control. Reliable evidence suggests that these techniques can be translated and applied within an athletic training and physical rehabilitation setting.

CONCLUSIONS

Athletic trainers are a vital component in providing health care for patients with ADHD. Using goal contagion creates a structured environment and positive reinforcements that accommodate patients with ADHD. Furthermore, ATs may use the evidence-based recommendations in this review to create a treatment and physical rehabilitation program and space that are tailored to the needs of the ADHD patient to increase the chance of a successful outcome.

Participation in Pre-High School Football and Neurological, Neuroradiological, and Neuropsychological Findings in Later Life: A Study of 45 Retired National Football League Players

BACKGROUND

A recent study found that an earlier age of first exposure (AFE) to tackle football was associated with long-term neurocognitive impairment in retired National Football League (NFL) players.

PURPOSE

To assess the association between years of exposure to pre-high school football (PreYOE) and neuroradiological, neurological, and neuropsychological outcome measures in a different sample of retired NFL players.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Forty-five former NFL players were included in this study. All participants prospectively completed extensive history taking, a neurological examination, brain magnetic resonance imaging, and a comprehensive battery of neuropsychological tests. To measure the associations between PreYOE and these outcome measures, multiple regression models were utilized while controlling for several covariates.

RESULTS

After applying a Bonferroni correction for multiple comparisons, none of the neurological, neuroradiological, or neuropsychological outcome measures yielded a significant relationship with PreYOE. A second Bonferroni-corrected analysis of a subset of these athletes with self-reported learning disability yielded no significant relationships on paper-and-pencil neurocognitive tests but did result in a significant association between learning disability and computerized indices of visual motor speed and reaction time.

CONCLUSION

The current study failed to replicate the results of a prior study, which concluded that an earlier AFE to tackle football might result in long-term neurocognitive deficits. In 45 retired NFL athletes, there were no associations between PreYOE and neuroradiological, neurological, and neuropsychological outcome measures.