The impact of attention deficit hyperactivity disorder on recovery from mild traumatic brain injury

Neuropsychological Performance and Its Predictors in the Early Treatment Phase of Non-CNS Pediatric Cancer

BACKGROUND

Pediatric cancer survivors can experience neuropsychological problems in the long term. Less is known about neuropsychological performance and its possible predictors in the early treatment phase of non-central nervous system (CNS) cancers.

PROCEDURE

This study describes the neuropsychological performance of 104 children with leukemia (n = 43), lymphoma (n = 29), or a non-CNS solid tumor (n = 33) aged 5-18 years at diagnosis (M = 11.78, SD = 3.71, 48% female), 4.52 months (SD = 0.77) after diagnosis. Using one-sample t-tests, measures of IQ, attention, memory, working memory, verbal fluency, processing speed, and reading were compared to age-matched norm scores. Individual comparisons were performed with paired t-tests, comparing participants' neuropsychological scores to their estimated IQ (EIQ). Multiple regression analyses related medical factors, pre-existing developmental vulnerabilities, and family psychosocial risk to neuropsychological outcomes, corrected for age at diagnosis, sex, and EIQ.

RESULTS

EIQ was significantly above the population mean (M = 105.25, SD = 12.15, p < 0.05), and most neuropsychological outcomes were within the average range compared to age-matched norms. Compared to their EIQ, however, participants' scores were on average significantly lower for almost all neuropsychological outcomes (p < 0.05). Medical factors, developmental vulnerabilities, and family psychosocial risk were not associated with neuropsychological outcomes (p > 0.05) in multivariable models. In a follow-up analysis, family psychosocial risk was related to memory (p < 0.05).

CONCLUSIONS

Children with non-CNS cancers perform within the average range on most neuropsychological tests. However, most scores are lower than participants' EIQ, revealing potential vulnerabilities. Family psychosocial risk may relate to memory. Future studies should include longitudinal follow-up and alternative predictors to clarify what contributes to early neuropsychological difficulties.

Accidental Physical Trauma in Children and Youth with Special Health Care Needs: A Scoping Review

BACKGROUND

Children and youth with special health care needs (CYSHCN) may be at greater risk for accidental physical trauma. Interventions should be informed by the literature indicating incident characteristics and at-risk subpopulations.

OBJECTIVE

To conduct a scoping review of accidental physical trauma in CYSHCN to characterize published literature and identify gaps.

DATA SOURCES

Peer-reviewed literature within CINAHL, Embase, and PubMed, 1998 to February 2021.

STUDY ELIGIBILITY CRITERIA

Studies that included individuals younger than 19 with special health care need(s) with accidental injuries classified as trauma.

STUDY APPRAISAL AND SYNTHESIS METHODS

The study team extracted: research method, author field, special health care needs, geographic scope, author country, demographics, incident characteristics, and injury characteristics.

RESULTS

We included 85 articles from an initial yield of 10,481. Pediatrics (32%) was the most-represented field among authors published on this topic. Publications most often considered developmental conditions (77.7%), including Attention Deficit Disorder/Attention Deficit Hyperactivity Disorder (ADD/ADHD). Studies differed in how often they reported demographic characteristics: gender (96.5%); social determinants of health/socioeconomic status (41.2%) or race and ethnicity (25.9%). Few articles included injury time of day (10.6%) and day of week (2.4%); 40% did not include information about the place of injury.

LIMITATIONS

Our search term development focused on diagnosis rather than need; we did not search reference lists or grey literature.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This review reveals key gaps in the literature pertaining to incident characteristics and place of injury for CYSHCN. Those advising families and/or planning interventions focused on mitigating risk for CYSHCN have limited evidence upon which to rely for certain conditions.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO registration is not applicable to scoping reviews.

Critical Review of Recently Published Studies Claiming Long-Term Neurocognitive Abnormalities in Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) is the most common claimed personal injury condition for which neuropsychologists are retained as forensic experts in litigation. Therefore, it is critical that experts have accurate information when testifying as to neurocognitive outcome from concussion. Systematic reviews and six meta-analyses from 1997 to 2011 regarding objective neurocognitive outcome from mTBI provide no evidence that concussed individuals do not return to baseline by weeks to months post-injury. In the current manuscript, a critical review was conducted of 21 research studies published since the last meta-analysis in 2011 that have claimed to demonstrate long-term (i.e., ≥12 months post-injury) neurocognitive abnormalities in adults with mTBI. Using seven proposed methodological criteria for research investigating neurocognitive outcome from mTBI, no studies were found to be scientifically adequate. In particular, more than 50% of the 21 studies reporting cognitive dysfunction did not appropriately diagnose mTBI, employ prospective research designs, use standard neuropsychological tests, include appropriate control groups, provide information on motive to feign or use PVTs, or exclude, or adequately consider the impact of, comorbid conditions known to impact neurocognitive scores. We additionally analyzed 15 studies published during the same period that documented no longer term mTBI-related cognitive abnormalities, and demonstrate that they were generally more methodologically robust than the studies purporting to document cognitive dysfunction. The original meta-analytic conclusions remain the most empirically-sound evidence informing our current understanding of favorable outcomes following mTBI.

Neuropsychological Evaluation in Traumatic Brain Injury

Neuropsychological evaluations can be helpful in the aftermath of traumatic brain injury. Cognitive functioning is assessed using standardized assessment tools and by comparing an individual's scores on testing to normative data. These evaluations examine objective cognitive functioning as well as other factors that have been shown to influence performance on cognitive tests (eg, psychiatric conditions, sleep) in an attempt to answer a specific question from referring providers. Referral questions may focus on the extent of impairment, the trajectory of recovery, or ability to return to work, sport, or the other previous activity.

Childhood Physical Health and Attention Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis of Modifiable Factors

Although neurobiologic and genetic factors figure prominently in the development of attention deficit/hyperactivity disorder (ADHD), adverse physical health experiences and conditions encountered during childhood may also play a role. Poor health is known to impact the developing brain with potential lifelong implications for behavioral issues. In attempt to better understand the relationship between childhood physical health and the onset and presence of ADHD symptoms, we summarized international peer-reviewed articles documenting relationships between a select group of childhood diseases or health events (e.g., illnesses, injuries, syndromes) and subsequent ADHD outcomes among children ages 0-17 years. Drawing on a larger two-phase systematic review, 57 longitudinal or retrospective observational studies (1978-2021) of childhood allergies, asthma, eczema, head injury, infection, or sleep problems and later ADHD diagnosis or symptomatology were identified and subjected to meta-analysis. Significant associations were documented between childhood head injuries, infections, and sleep problems with both dichotomous and continuous measures of ADHD, and between allergies with dichotomous measures of ADHD. We did not observe significant associations between asthma or eczema with ADHD outcomes. Heterogeneity detected for multiple associations, primarily among continuously measured outcomes, underscores the potential value of future subgroup analyses and individual studies. Collectively, these findings shed light on the importance of physical health in understanding childhood ADHD. Possible etiologic links between physical health factors and ADHD are discussed, as are implications for prevention efforts by providers, systems, and communities.

Regional associations of white matter integrity and neurological, post-traumatic stress disorder and autonomic symptoms in Veterans with and without history of loss of consciousness in mild TBI

Background

Posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) share overlapping symptom presentations and are highly comorbid conditions among Veteran populations. Despite elevated presentations of PTSD after mTBI, mechanisms linking the two are unclear, although both have been associated with alterations in white matter and disruptions in autonomic regulation. The present study aimed to determine if there is regional variability in white matter correlates of symptom severity and autonomic functioning in a mixed sample of Veterans with and without PTSD and/or mTBI (N = 77).

Methods

Diffusion-weighted images were processed to extract fractional anisotropy (FA) values for major white matter structures. The PTSD Checklist-Military version (PCL-M) and Neurobehavioral Symptom Inventory (NSI) were used to determine symptom domains within PTSD and mTBI. Autonomic function was assessed using continuous blood pressure and respiratory sinus arrythmia during a static, standing angle positional test. Mixed-effect models were used to assess the regional specificity of associations between symptom severity and white matter, with FA, global symptom severity (score), and white matter tract (tract) as predictors. Additional interaction terms of symptom domain (i.e., NSI and PCL-M subscales) and loss of consciousness (LoC) were added to evaluate potential moderating effects. A parallel analysis was conducted to explore concordance with autonomic functioning.

Results

Results from the two-way Score × Tract interaction suggested that global symptom severity was associated with FA in the cingulum angular bundle (positive) and uncinate fasciculus (negative) only, without variability by symptom domain. We also found regional specificity in the relationship between FA and autonomic function, such that FA was positively associated with autonomic function in all tracts except the cingulum angular bundle. History of LoC moderated the association for both global symptom severity and autonomic function.

Conclusions

Our findings are consistent with previous literature suggesting that there is significant overlap in the symptom presentation in TBI and PTSD, and white matter variability associated with LoC in mTBI may be associated with increased PTSD-spectra symptoms. Further research on treatment response in patients with both mTBI history and PTSD incorporating imaging and autonomic assessment may be valuable in understanding the role of brain injury in treatment outcomes and inform treatment design.

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.

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.

Post-Traumatic Epilepsy and Comorbidities: Advanced Models, Molecular Mechanisms, Biomarkers, and Novel Therapeutic Interventions

Post-traumatic epilepsy (PTE) is one of the most devastating long-term, network consequences of traumatic brain injury (TBI). There is currently no approved treatment that can prevent onset of spontaneous seizures associated with brain injury, and many cases of PTE are refractory to antiseizure medications. Post-traumatic epileptogenesis is an enduring process by which a normal brain exhibits hypersynchronous excitability after a head injury incident. Understanding the neural networks and molecular pathologies involved in epileptogenesis are key to preventing its development or modifying disease progression. In this article, we describe a critical appraisal of the current state of PTE research with an emphasis on experimental models, molecular mechanisms of post-traumatic epileptogenesis, potential biomarkers, and the burden of PTE-associated comorbidities. The goal of epilepsy research is to identify new therapeutic strategies that can prevent PTE development or interrupt the epileptogenic process and relieve associated neuropsychiatric comorbidities. Therefore, we also describe current preclinical and clinical data on the treatment of PTE sequelae. Differences in injury patterns, latency period, and biomarkers are outlined in the context of animal model validation, pathophysiology, seizure frequency, and behavior. Improving TBI recovery and preventing seizure onset are complex and challenging tasks; however, much progress has been made within this decade demonstrating disease modifying, anti-inflammatory, and neuroprotective strategies, suggesting this goal is pragmatic. Our understanding of PTE is continuously evolving, and improved preclinical models allow for accelerated testing of critically needed novel therapeutic interventions in military and civilian persons at high risk for PTE and its devastating comorbidities. SIGNIFICANCE STATEMENT: Post-traumatic epilepsy is a chronic seizure condition after brain injury. With few models and limited understanding of the underlying progression of epileptogenesis, progress is extremely slow to find a preventative treatment for PTE. This study reviews the current state of modeling, pathology, biomarkers, and potential interventions for PTE and comorbidities. There's new optimism in finding a drug therapy for preventing PTE in people at risk, such as after traumatic brain injury, concussion, and serious brain injuries, especially in military persons.

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.

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.

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.

Impact of Secondary ADHD on Long-Term Outcomes After Early Childhood Traumatic Brain Injury

OBJECTIVE

To examine the impact of secondary attention-deficit/hyperactivity disorder (SADHD) on long-term global and executive functioning in adolescents after traumatic brain injury (TBI).

SETTING

Three tertiary cared children's hospitals and 1 general hospital.

PARTICIPANTS

One hundred twenty children (TBI: n = 54; orthopedic injury: n = 66) without preinjury ADHD evaluated approximately 6.8 years postinjury.

DESIGN

Cross-sectional data analysis from a prospective, longitudinal study.

MAIN MEASURES

Outcomes included functional impairment (Child and Adolescent Functional Assessment Scale) and executive functioning (Behavior Rating Inventory of Executive Function [BRIEF]).

RESULTS

SADHD moderated the association of injury type with the BRIEF-Behavioral Regulation Index (F1,113 = 4.42, P = .04) and the Child and Adolescent Functional Assessment Scale (F1,112 = 8.95, P = .003). TBI was only associated with poorer outcomes in the context of SADHD. SADHD was also associated with poorer outcomes on the BRIEF-Global Executive Composite (F1,113 = 52.92, P < .0001) and BRIEF-Metacognitive Index scores (F1,113 = 48.64, P < .0001) across groups. Adolescents with TBI had greater BRIEF-Global Executive Composite scores than those with orthopedic injury (F1,113 = 5.00, P = .03).

CONCLUSIONS

Although SADHD was associated with poorer functioning across groups, its adverse effects on behavioral regulation and overall functioning were amplified following TBI. TBI + SADHD may confer an elevated risk for significant impairments in early adolescence.

Preseason Vestibular Ocular Motor Screening in Children and Adolescents

OBJECTIVES

The primary purpose of this study was to examine vestibular/ocular motor screening (VOMS) test performance in a sample of healthy youth ice hockey players. A particular focus was to investigate the potential effects of age and pre-existing health conditions, including concussion history, attention-deficit/hyperactivity disorder (ADHD), learning disability (LD), headaches/migraines, and depression/anxiety on preseason baseline VOMS performance, including the near point of convergence (NPC) distance.

DESIGN

Cross-sectional cohort.

SETTING

Outpatient physiotherapy clinic.

PARTICIPANTS

Three hundred eighty-seven male youth hockey players, with an average age of 11.9 years (SD = 2.2, range = 8-17), completed the VOMS and responded to self- or parent-reported demographic and medical history questionnaires during preseason baseline assessments.

INDEPENDENT VARIABLES ASSESSED

Age, sex, and mental and physical health history including ADHD, headaches, depression, anxiety, migraine, and LD.

OUTCOME MEASURE

Vestibular/ocular motor screening.

RESULTS

The large majority of boys scored within normal limits on the VOMS, ie, they reported no symptom provocation of more than 2 points on any VOMS subset (89%) and had a normal NPC distance, ie, <5 cm (78%). The individual VOMS subtests had low abnormality rates, and demographic and pre-existing health conditions, such as age, headache or migraine history, previous neurodevelopmental conditions, or mental health problems, were not associated with clinically meaningful symptom provocation during the VOMS.

CONCLUSIONS

There was a low rate of abnormal findings for the individual VOMS subtests, with the exception of NPC distance, among male youth hockey players during preseason assessment.

Childhood Neurotoxicity and Brain Resilience to Adverse Events during Adulthood

OBJECTIVE

This study used childhood cancer survivors as a novel model to study whether children who experience central nervous system (CNS) injury are at higher risk for neurocognitive impairment associated with subsequent late onset chronic health conditions (CHCs).

METHODS

Adult survivors of childhood cancer (n = 2,859, ≥10 years from diagnosis, ≥18 years old) completed a comprehensive neurocognitive battery and clinical examination. Neurocognitive impairment was defined as age-adjusted z score < 10th percentile. Participants impaired on ≥3 tests had global impairment. CHCs were graded using the Common Terminology Criteria for Adverse Events v4.3 (grade 1, mild; 2, moderate; 3, severe/disabling; 4, life-threatening) and were combined into a severity/burden score by frequency and grade (none/low, medium, high, and very high). A total of 1,598 survivors received CNS-directed therapy including cranial radiation, intrathecal methotrexate, or neurosurgery. Logistic regression estimated the odds of neurocognitive impairment associated with severity/burden score and grade 2 to 4 conditions, stratified by CNS treatment.

RESULTS

CNS-treated survivors performed worse than non-CNS-treated survivors on all neurocognitive tests and were more likely to have global neurocognitive impairment (46.9% vs 35.3%, p < 0.001). After adjusting for demographic and treatment factors, there was a dose-response association between severity/burden score and global neurocognitive impairment, but only among CNS-treated survivors (high odds ratio [OR] = 2.24, 95% confidence interval [CI] = 1.42-3.53; very high OR = 4.07, 95% CI = 2.30-7.17). Cardiovascular and pulmonary conditions were associated with processing speed, executive function, and memory impairments in CNS-treated but not non-CNS-treated survivors who were impacted by neurologic conditions.

INTERPRETATION

Reduced cognitive/brain reserve associated with CNS-directed therapy during childhood may make survivors vulnerable to adverse cognitive effects of cardiopulmonary conditions during adulthood. ANN NEUROL 2021;89:534-545.

Predictors of Concussion Outcomes in Individuals With ADHD

OBJECTIVES

To describe and delineate the epidemiological profile of concussion injuries in individuals with attention-deficit/hyperactivity disorder (ADHD) by identifying characteristics associated with poorer outcomes.

SETTING

One hundred forty-four multidisciplinary concussion-specialized clinics across Canada.

PARTICIPANTS

Two hundred twenty-two individuals with a diagnosis of ADHD aged 7 to 53 years who sustained a concussion within the last year.

DESIGN

Multicenter cohort study.

MAIN MEASURES

Candidate predictor variables (ie, age, sex, concussion history, loss of consciousness, and internalized and learning disorder comorbidities) were collected through oral interviews. Concussion outcomes (ie, symptom severity and total number of symptoms experienced) were assessed with the Sport Concussion Assessment Tool.

RESULTS

Older age, female sex, and the presence of an internalized disorder predicted poorer concussion outcomes in individuals with ADHD. Males with ADHD reported significantly worse concussion outcomes with increasing age, while outcomes remained fairly stable across age in females.

CONCLUSION

The current findings represent a promising step toward the optimization of concussion management in individuals with ADHD. With a more thorough understanding of the demographic and comorbidity variables, clinical care decisions and intervention strategies can be developed to help individuals with ADHD who might be at a higher risk of poorer outcomes following a concussion.

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.

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.

The association between attention deficit hyperactivity disorder severity and risk of mild traumatic brain injury in children with attention deficit hyperactivity disorder in the United States of America: A cross-sectional study of data from the National Survey of Children with Special Health Care Needs

BACKGROUND

As children with attention deficit hyperactivity disorder (ADHD) have shown to be at higher risk of accidents and injury, one may assume that they may also bear a higher likelihood of mild traumatic brain injuries (mTBI). However, the current scientific evidence whether ADHD severity is associated with traumatic brain injuries is controversial. The objective of this study was too assess the association between the severity of ADHD and prevalence of mTBI in 0- to 18-year-old children with ADHD in the United States.

METHODS

Cross-sectional study using secondary data gathered in 2009/10 from the National Survey of Children with Special Healthcare Needs. After excluding comorbidity and those with nonspecific attention deficits, the final study population consisted of 10,739 children with ADHD from 40,052 households. The main exposure variable was self-reported ADHD severity (mild, moderate, or severe). The main outcome was mTBI, defined as head injury, traumatic brain injury, and/or concussion). Covariates included age, gender and race, medication status. Unadjusted and adjusted logistic regression analysis were used.

RESULTS

Children with more severe ADHD had consistently increased incidences of mTBI. Adjusted logistic regression analysis revealed a statistically significant association between severity of ADHD and occurrence of mTBI. The corresponding odds ratios were 1.57 (95% confidence interval (CI) [1.13, 2.18] for moderate, and 1.79 (95% CI [1.18, 2.72]) for severe ADHD, respectively, compared with mild ADHD. In males, children with moderate and severe ADHD had increased odds of mTBI. The corresponding odds ratio for mTBI in those with moderate ADHD was 1.60 (95% CI [1.07, 2.39]) and 1.86 (95% CI [1.15, 3.00]) for severe ADHD, respectively. No associations between severity and mTBI were found in girls.

CONCLUSIONS

As ADHD severity was associated with incidence of mTBI, it is important to identify those who need increased attention and counselling to prevent injury.

Influence of Methylphenidate on Long-Term Neuropsychological and Everyday Executive Functioning After Traumatic Brain Injury in Children with Secondary Attention Problems

OBJECTIVE

To investigate the effects of methylphenidate on long-term executive and neuropsychological functioning in children with attention problems following TBI, as well as the relationship between methylphenidate associated changes in lab-based neuropsychological measures of attentional control, processing speed, and executive functioning and parent- or self-report measures of everyday executive functioning.

METHOD

26 children aged 6-17 years, who were hospitalized for moderate-to-severe blunt head trauma 6 or more months previously, were recruited from a large children's hospital medical center. Participants were randomized into a double-masked, placebo-controlled cross-over clinical trial. Participants completed a comprehensive neuropsychological battery and parent- and self-report ratings of everyday executive functioning at baseline, and at 4 weeks and 8 weeks following upward titration of medication to an optimal dose or while administered a placebo.

RESULTS

Methylphenidate was associated with significant improvements in processing speed, sustained attention, and both lab-based and everyday executive functioning. Significant treatment-by-period interactions were found on a task of sustained attention. Participants who were randomized to the methylphenidate condition for the first treatment period demonstrated random or erratic responding, with slower and more variable response times when given placebo during the second period.

CONCLUSION

Results indicate that methylphenidate treatment is associated with positive outcomes in processing speed, sustained attention, and both lab-based and everyday measures of executive functioning compared to placebo group. Additionally, results suggest sustained attention worsens when discontinuing medication. (JINS, 2019, 25, 740-749).

On-Field Signs Predict Future Acute Symptoms After Sport-Related Concussion: A Structural Equation Modeling Study

OBJECTIVES

This study investigated the relationship between on-field, objective signs immediately following sport-related concussion and self-reported symptom endorsement within 1 day post injury.

METHODS

A retrospective case series of 237 concussed high school athletes was performed. On-field signs were evaluated immediately post injury. Self-reported symptoms (2 clusters) were collected within 1 day post injury. A two-step structural equation model and follow-up bivariate regression analyses of significant on-field signs and symptom clusters were performed.

RESULTS

Signs of immediate memory, β=0.20, p=.04, and postural instability, β=0.19, p < .01, significantly predicted a greater likelihood of endorsing the cognitive-migraine-fatigue symptom cluster within 1 day post injury. Regarding signs correlated with specific symptoms, immediate memory was associated with symptoms of trouble remembering, χ 2 =37.92, p < .001, odds ratio (OR)=3.89 (95% confidence interval (CI) [2.47, 6.13]), and concentration difficulties, χ 2 =10.84, p=.001, OR=2.13 (95% CI [1.37, 3.30]). Postural instability was associated with symptom endorsement of trouble remembering, χ 2 =12.08, p < .001, OR=1.76 (95% CI [1.29, 2.40]).

CONCLUSIONS

Certain post-concussion on-field signs exhibited after injury were associated with specific symptom endorsement within 1 day post injury. Based on these associations, individualized education-based interventions and academic accommodations may help reduce unanticipated worry from parents, students, and teachers following a student-athlete's sport-related concussion, especially in cases of delayed onset symptoms. (JINS, 2018, 24, 476-485).

Traumatic Brain Injury, Sleep Disorders, and Psychiatric Disorders: An Underrecognized Relationship

Traumatic brain injury (TBI) is commonplace among pediatric patients and has a complex, but intimate relationship with psychiatric disease and disordered sleep. Understanding the factors that influence the risk for the development of TBI in pediatrics is a critical component of beginning to address the consequences of TBI. Features that may increase risk for experiencing TBI sometimes overlap with factors that influence the development of post-concussive syndrome (PCS) and recovery course. Post-concussive syndrome includes physical, psychological, cognitive and sleep-wake dysfunction. The comorbid presence of sleep-wake dysfunction and psychiatric symptoms can lead to a more protracted recovery and deleterious outcomes. Therefore, a multidisciplinary evaluation following TBI is necessary. Treatment is generally symptom specific and mainly based on adult studies. Further research is necessary to enhance diagnostic and therapeutic approaches, as well as improve the understanding of contributing pathophysiology for the shared development of psychiatric disease and sleep-wake dysfunction following TBI.

Attention-deficit/hyperactivity disorder is associated with baseline child sport concussion assessment tool third edition scores in child hockey players

OBJECTIVES

The objectives of this study were to report baseline, preseason data for the Child-SCAT3, stratified by attention deficit hyperactivity disorder (ADHD) status, and examine group differences in Child-SCAT3 performance between children with and without ADHD.

DESIGN

Cross-sectional study.

METHODS

Young male hockey players (n = 304), aged 8-12 years, were administered the Child-SCAT3 during pre-season. Child-SCAT3 measures included a 20-item symptom scale, a Standardised Assessment of Concussion Child Version (SAC-C), a modified Balance Error Scoring System (m-BESS), a tandem gait task, and a coordination test.

RESULTS

Children with ADHD (n = 20) endorsed significantly more symptoms (d = 0.95) and greater symptom severity (d = 1.13) compared to children without ADHD. No statistically significant differences were found between groups on Child-SCAT3 measures of cognitive or physical functioning (e.g. balance and coordination).

CONCLUSIONS

ADHD should be considered when interpreting Child-SCAT3 scores, especially symptom reporting, in the context of concussion assessment. Better understanding of symptom reporting in uninjured child athletes with ADHD can inform the clinical interpretation of symptoms at baseline and following an actual or suspected concussion. Normative data for the Child-SCAT3 that is not stratified by or otherwise accounts for ADHD status should be used with caution when appraising performance of children with ADHD.

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.

The effect of premorbid attention-deficit/hyperactivity disorder on neuropsychological functioning in individuals with acute mild traumatic brain injuries

INTRODUCTION

Mild traumatic brain injury (mTBI) is a frequent, yet undertreated condition that typically manifests with transient neurological and cognitive symptoms that resolve over the course of several weeks. In contrast, attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that presents initially in childhood but often persists into adulthood. mTBI and ADHD include overlapping symptomatology, making it difficult for clinicians to disentangle the sequelae of each condition when they co-occur in the same individual. We hypothesized that neuropsychological tests would be sensitive to preexisting ADHD in inpatients with acute mTBIs.

METHOD

We retrospectively examined the medical charts of 100 inpatients, aged 18-40 years (96% Caucasian; 77% male) with mTBIs in an acute care setting, half of whom had self-reported the presence of premorbid ADHD, and half of whom were matched controls. We analyzed group differences across neuropsychological tests of attention, processing speed, and executive functions, examined the profile ratings of independent, blinded, board-certified neuropsychologists, and correlated cognitive performance with time from traumatic injury to testing.

RESULTS

Individuals with premorbid ADHD (a) performed significantly worse than their matched counterparts on several tests of attention, processing speed, and working memory, and (b) were significantly more likely to produce profiles later rated as impaired by independent, board-certified clinical neuropsychologists. In addition, time from traumatic injury to testing was found to be negatively correlated with neurocognitive performance.

CONCLUSIONS

These findings (a) argue for the utility of a brief assessment of premorbid ADHD in the acute care of individuals with mTBIs and (b) provide clinicians with a barometer for gauging the relative contributions of premorbid ADHD to neuropsychological impairments in the neurocognitive profiles of individuals with mTBIs. Reported effect sizes will assist clinicians in accurately weighing the impact of premorbid ADHD when interpreting such profiles.

Mild Traumatic Brain Injury and Attention-Deficit Hyperactivity Disorder in Young Student Athletes

A recent meta-analysis documented a significant statistical association between mild traumatic brain injury (mTBI) and attention deficit hyperactivity disorder (ADHD) (Adeyemo et al., 2014), but the direction of this effect was unclear. In this study, we hypothesized that ADHD would be an antecedent risk factor for mTBI. Participants were student athletes ages 12 to 25 who had sustained a mTBI and Controls of similar age and sex selected from studies of youth with and without ADHD. Subjects were assessed for symptoms of ADHD, concussion severity, and cognitive function. mTBI subjects had a significantly higher rate of ADHD than Controls, and in all cases the age of onset of ADHD was before mTBI onset. mTBI+ADHD subjects also had more severe concussion symptoms (fatigue and poor concentration) than mTBI-ADHD subjects. These results support ADHD as an antecedent risk factor for mTBI in student athletes and that its presence complicates the course of mTBI.

The association between traumatic brain injury and ADHD in a Canadian adult sample

OBJECTIVE

This study describes the association between lifetime traumatic brain injury (TBI) and attention deficit and hyperactivity disorder (ADHD) among Canadian adults.

METHOD

A cross-sectional sample of 3993 Ontario adults aged 18 or older were surveyed by Computer Assisted Telephone Interviewing (CATI) throughout 2011 and 2012 as part of the CAMH Monitor, a rolling survey assessing the health, mental health and substance use of Ontario adults. TBI was defined as trauma to the head that resulted in loss of consciousness for at least five minutes or overnight hospitalization. ADHD was measured by the 6-item ASRS screener for adult ADHD, and self-reported history of diagnosed ADHD.

RESULTS

Among adults with a history of TBI, 6.6% (95% CI: 4.7, 9.4) screened ADHD positive, and 5.9% (95% CI: 3.6, 9.5) reported having been diagnosed with ADHD in their lifetime. Adults with lifetime TBI had significantly greater odds of scoring positive on the ADHD/ASRS screen (OR = 2.49, 95% CI: 1.54, 4.04), and of reporting a history of diagnosed ADHD (OR = 2.64, 95% CI: 1.40, 4.98) than without TBI, when holding values of sex, age, and education constant.

CONCLUSION

Significant positive associations between lifetime TBI and both current and past ADHD were observed among adults in this population. More research to understand these associations, and their significance for the etiology and management of TBI and ADHD, is needed.

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

OBJECTIVE

To investigate whether attention deficit hyperactivity disorder (ADHD) influences postconcussion recovery, as measured by computerized neurocognitive testing.

DESIGN

This is a retrospective case control study.

SETTING

Computer laboratories across 10 high schools in the greater Atlanta, Georgia area.

PARTICIPANTS

Immediate postconcussion assessment and cognitive testing (ImPACT) scores of 70 athletes with a self-reported diagnosis of ADHD and who sustained a sport-related concussion were compared with a randomly selected age-matched control group. Immediate postconcussion assessment and cognitive testing scores over a 5-year interval were reviewed for inclusion.

MAIN OUTCOME MEASURES

Postconcussion recovery was defined as a return to equivalent baseline neurocognitive score on the ImPACT battery, and a concussion symptom score of ≤7.

RESULTS

Athletes with ADHD had on average a longer time to recovery when compared with the control group (16.5 days compared with 13.5 days), although not statistically significant. The number of previous concussions did not have any effect on the rate of recovery in the ADHD or the control group. In addition, baseline neurocognitive testing did not statistically differ between the 2 groups, except in verbal memory.

CONCLUSIONS

Although not statistically significant, youth athletes with ADHD took on average 3 days longer to return to baseline neurocognitive testing compared with a control group without ADHD.

CLINICAL RELEVANCE

Youth athletes with ADHD may have a marginally prolonged recovery as indexed by neurocognitive testing and should be considered when prognosticating time to recovery in this subset of student athletes.

Ice Hockey Summit II: zero tolerance for head hits and fighting

OBJECTIVE

To present currently known basic science and on-ice influences of sport-related concussion (SRC) in hockey, building on the Ice Hockey Summit I action plan (2011) to reduce SRC.

METHODS

The prior summit proceedings included an action plan intended to reduce SRC. As such, the proceedings from Summit I served as a point of departure, for the science and discussion held during Summit II (Mayo Clinic, Rochester MN, October 2013). Summit II focused on (1) Basic Science of Concussions in Ice Hockey: Taking Science Forward; (2) Acute and Chronic Concussion Care: Making a Difference; (3) Preventing Concussions via Behavior, Rules, Education and Measuring Effectiveness; (4) Updates in Equipment: their Relationship to Industry Standards; and (5) Policies and Plans at State, National and Federal Levels to reduce SRC. Action strategies derived from the presentations and discussion described in these sectors were subsequently voted on for purposes of prioritization. The following proceedings include knowledge and research shared by invited faculty, many of whom are health care providers and clinical investigators.

RESULTS

The Summit II evidence-based action plan emphasizes the rapidly evolving scientific content of hockey SRC. It includes the most highly prioritized strategies voted on for implementation to decrease concussion.

CONCLUSIONS

The highest priority action items identified from the Summit includes the following: (1) eliminate head hits from all levels of ice hockey, (2) change body-checking policies, and (3) eliminate fighting in all amateur and professional hockey.

Blood manganese levels in relation to comorbid behavioral and emotional problems in children with attention-deficit/hyperactivity disorder

Patients with attention-deficit/hyperactivity disorder (ADHD) appear to be more vulnerable to the development of other psychiatric disorders than the general population. The proposed neurotoxic mechanisms of manganese involve striatal dopamine neurotransmission, implicated in the pathophysiology of ADHD. We investigated whether the adverse impact of manganese is particularly pronounced in children with ADHD. Blood manganese concentration and diagnosis of ADHD were assessed in a general population of 890 children, aged 8-11 years. The main outcome measure was the Child Behavior Checklist (CBCL). A significant interaction was found between ADHD status and blood manganese level in predicting CBCL total problems score as well as anxiety/depression, social problems, delinquent behavior, aggressive behavior, internalizing problems, and externalizing problems. The directions of the interactions indicated that blood manganese level was more positively correlated with CBCL scores in ADHD children than in the healthy population. In ADHD children, only the fifth quintile of blood manganese concentration was significantly associated with the CBCL total problems score. ADHD children may be more vulnerable than the general school-age population to the neurotoxic effects of manganese exposure, which lead to an elevated risk of developing comorbid mental conditions.

Functional plasticity in childhood brain disorders: when, what, how, and whom to assess

At every point in the lifespan, the brain balances malleable processes representing neural plasticity that promote change with homeostatic processes that promote stability. Whether a child develops typically or with brain injury, his or her neural and behavioral outcome is constructed through transactions between plastic and homeostatic processes and the environment. In clinical research with children in whom the developing brain has been malformed or injured, behavioral outcomes provide an index of the result of plasticity, homeostasis, and environmental transactions. When should we assess outcome in relation to age at brain insult, time since brain insult, and age of the child at testing? What should we measure? Functions involving reacting to the past and predicting the future, as well as social-affective skills, are important. How should we assess outcome? Information from performance variability, direct measures and informants, overt and covert measures, and laboratory and ecological measures should be considered. In whom are we assessing outcome? Assessment should be cognizant of individual differences in gene, socio-economic status (SES), parenting, nutrition, and interpersonal supports, which are moderators that interact with other factors influencing functional outcome.

Mild traumatic brain injury and ADHD: a systematic review of the literature and meta-analysis

OBJECTIVE

This study investigated the association between mild traumatic brain injury (mTBI) and ADHD, which increases risk of injuries and accidents.

METHOD

We conducted a systematic review and meta-analysis of studies that examined the relationship between mTBI and ADHD.

RESULTS

Five studies, comprising 3,023 mTBI patients and 9,716 controls, fit our a priori inclusion and exclusion criteria. A meta-analysis found a significant association between ADHD and mTBI, which was significant when limited to studies that reported on ADHD subsequent to mTBI and when the direction of the association was not specified, but not for studies that reported mTBI subsequent to ADHD. Heterogeneity of effect size and publication biases were not evident.

CONCLUSION

The literature documents a significant association between mTBI and ADHD. Further clarification of the relationship and direction of effect between mTBI and ADHD and treatment implications could have large clinical, scientific, and public health implications.