No cumulative effects for one or two previous concussions

Identifying the 'Miserable Minority' Among Pediatric Patients Following Concussion

OBJECTIVES

To investigate whether there are empirically-detectable subgroups of concussion severity and recovery across three consecutive concussions, as well as to define risk factor and clinical assessment differences across subgroups.

METHODS

The present study was a retrospective chart review of 202 adolescents 13.17 ± 1.99 years old who presented to a concussion specialty clinic within 30 days of injury for multiple injuries between 2019 and 2020. Participants included patients from a specialty clinic for two (n = 202) or three (n = 68) total concussions. Latent class analysis (LCA) was used to identify subgroups based upon concussion symptom severity and recovery time. Risk factors (sex, age at first injury, and histories of anxiety, depression, migraine, motion sickness, ocular dysfunction, and attention-deficit/hyperactivity disorder [ADHD] or learning disability [LD]) were compared across subgroups.

RESULTS

A two-class solution yielded one group of 163 participants characterized by lower symptoms and shorter recovery times (80.7%, "normal") and 39 participants (19.3%, "miserable minority") characterized by higher symptoms and longer recovery times. Only female sex (OR = 4.91, p = 0.005) was a significant predictor of class membership. The miserable group presented for treatment nearly 4 days later (9.41 days) compared to the normal group (5.74 days) for the first injury, and almost 2 days later for the second injury (7.33 vs 5.26 days).

CONCLUSIONS

Approximately 1 in 5 patients who presented to a concussion specialty clinic for a repeat concussion were classified in the miserable minority subgroup. This subgroup was characterized by markedly higher initial symptom burdens and over double the recovery time.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III evidence.

Neck strength and force in reaction time task of adolescent athletes with and without concussion history: A pilot study

OBJECTIVES

Assess the impact of concussion by comparing reaction time, peak force recruitment, and rate of force development of adolescent athletes returning from concussion against age- and sex-matched controls in visual-elicited neck movement.

DESIGN

Athletes sat secured in a custom-built isometric device with their heads secured in a helmet and attached to a 6-axis load cell. They performed neck flexion, extension, and lateral flexion in response to a visual cue. Three trials in each direction were used for statistical analyses; peak force and rate of force development were normalized against athlete mass.

SETTING

Laboratory.

PARTICIPANTS

26 adolescent/young adult athletes (8F/18M), either recently concussed (and cleared for return to sport) or an age- and sex-matched healthy control.

MAIN OUTCOME MEASURES

Reaction time, angle, standard deviation of angle, deviation from target angle, peak force, and RFD over 50, 100, 150,and 200 ms of movement were measured for each trial.

RESULTS

Concussed athletes had decreased normalized peak force (P = 0.008) and rate of force development (P < 0.001-0.007). In neck extension, concussed athletes also had decreased movement precision (P = 0.012).

CONCLUSIONS

Concussion is associated with alterations of neck biomechanics that decrease overall neck strength.

Lifetime Traumatic Brain Injury and Cognitive Domain Deficits in Late Life: The PROTECT-TBI Cohort Study

Traumatic brain injury (TBI) causes cognitive impairment but it remains contested regarding which cognitive domains are most affected. Further, moderate-severe TBI is known to be deleterious, but studies of mild TBI (mTBI) show a greater mix of negative and positive findings. This study examines the longer-term cognitive effects of TBI severity and number of mTBIs in later life. We examined a subset (n = 15,764) of the PROTECT study, a cohort assessing risk factors for cognitive decline (ages between 50 and 90 years). Participants completed cognitive assessments annually for 4 years. Cognitive tests were grouped using a principal components analysis (PCA) into working memory, episodic memory, attention, processing speed, and executive function. Lifetime TBI severity and number were retrospectively recalled by participants using the Brain Injury Screening Questionnaire (BISQ). Linear mixed models (LMMs) examined the effect of severity of head injury (non-TBI head strike, mTBI, and moderate-severe TBI) and number of mTBI at baseline and over time. mTBI was considered as a continuous and categorical variable (groups: 0 mTBI, 1 mTBI, 2 mTBIs, 3 mTBIs, and 4+ mTBIs). Of the participants 5725 (36.3%) reported at least one mTBI and 510 (3.2%) at least one moderate-severe TBI, whereas 3711 (23.5%) had suffered at worst a non-TBI head strike and 5818 (32.9%) reported no head injuries. The participants had suffered their last reported head injury an average (standard deviation, SD) of 29.6 (20.0) years prior to the study. Regarding outcomes, there was no worsening in longitudinal cognitive trajectories over the study duration but at baseline there were significant cognitive deficits associated with TBI. At baseline, compared with those without head injury, individuals reporting at least one moderate-severe TBI had significantly poorer attention (B = -0.163, p < 0.001), executive scores (B = -0.151, p = 0.004), and processing speed (B = -0.075, p = 0.033). Those who had suffered at least a single mTBI also demonstrated significantly poorer attention scores at baseline compared with the no head injury group (B = -0.052, p = 0.001). Compared with those with no mTBI, those in the 3 mTBI group manifested poorer baseline executive function (B = -0.149, p = 0.025) and attention scores (B = -0.085, p = 0.015). At baseline, those who had suffered four or more mTBIs demonstrated poorer attention (B = -0.135, p < 0.001), processing speed (B = -0.072, p = 0.009), and working memory (B = -0.052, p = 0.036), compared with those reporting no mTBI. TBI is associated with fixed, dose, and severity-dependent cognitive deficits. The most sensitive cognitive domains are attention and executive function, with approximately double the effect compared with processing speed and working memory. Post-TBI cognitive rehabilitation should be targeted appropriately to domain-specific effects. Significant long-term cognitive deficits were associated with three or more lifetime mTBIs, a critical consideration when counseling individuals post-TBI about continuing high-risk activities.

Incremental Effects of Subsequent Concussions on Cognitive Symptoms in the Sport Concussion Assessment Tool

OBJECTIVE

Patients who are fully recovered from a concussion may still be more vulnerable in the face of subsequent concussions. This study examines symptoms associated with repeated concussions in young and otherwise healthy adults.

DESIGN

Cross sectional.

SETTING

Institutional study at a university setting.

PARTICIPANTS

University students with a history of concussion.

INDEPENDENT VARIABLES

Participants were grouped based on numbers of concussions.

MAIN OUTCOME MEASURES

The impact of incremental concussion on symptom clusters in Sport Concussion Assessment Tools 5 and Spearman ranking correlation coefficients between symptom clusters.

RESULTS

One hundred thirty-five participants reported having had 1 concussion, 63 reported 2 concussions, 50 reported 3 concussions, and 43 reported 4 to 6 concussions. Total severity scores over the range of concussion number (1, 2, 3, and greater than 3) did not show a clear incremental effect. However, average scores of cognitive symptoms rose with each subsequent concussion ( P ≤ 0.05). The largest incremental effect observed was that of second concussions on emotional symptom scores (t = 5.85, P < 0.01). Symptoms in the emotional and cognitive clusters were the most correlated regardless of the number of reported concussions; the correlations were lowest with symptoms associated with sensitivity to light or noise.

CONCLUSIONS

The incremental rise of cognitive symptom scores with each concussion affirms the importance of cognitive impairment in concussion assessment and implies a cumulative brain vulnerability that persists even after symptom resolution. The cognitive-emotional symptom clusters may reflect underlying concussion-induced impairments in the corticostriatothalamocortical (CSTC) networks, although sensitivity symptoms are potentially attributable to different neural correlates.

Preseason Symptom Reporting and Cognition in Middle School Athletes with Past Concussions

This study examined the association between past concussions and current preseason symptom reporting and cognitive performance in 9,257 youth ages 11-13. Participants completed neurocognitive testing prior to participating in a school sports between 2009 and 2019. We stratified the sample by gender and number of prior concussions and assessed group differences on the Post-Concussion Symptom Scale total score and the ImPACT cognitive composite scores. Those with≥2 prior concussions reported more symptoms than those with 0 concussions (d=0.43-0.46). Multiple regressions examining the contribution of concussion history and developmental/health history to symptom reporting showed the most significant predictors of symptoms scores were (in descending order): treatment for a psychiatric condition, treatment for headaches, history of learning disability (in boys only), history of attention-deficit/hyperactivity disorder, and age. Concussion history was the weakest statistically significant predictor in boys and not significant in girls. Cognitively, boys with 1 prior concussion had worse speed those with 0 concussions (d=0.11), and girls with≥2 prior concussions had worse verbal/visual memory than girls with 0 concussions (ds=0.38-0.39). In summary, youth with≥2 prior concussions reported more symptoms than those with no concussions. Boys with multiple concussions performed similarly on cognitive testing, while girls had worse memory scores.

A Normative Reference vs. Baseline Testing Compromise for ImPACT: The CARE Consortium Multiple Variable Prediction (CARE-MVP) Norms

BACKGROUND

Sports medicine clinicians routinely use computerized neurocognitive testing in sport-related concussion management programs. Debates continue regarding the appropriateness of normative reference comparisons versus obtaining individual baseline assessments, particularly for populations with greater likelihood of having below- or above-average cognitive abilities. Improving normative reference methods could offer alternatives to perceived logistical and financial burdens imposed by universal baseline testing.

OBJECTIVES

To develop and validate the Concussion Assessment, Research, and Education (CARE) Consortium Multiple Variable Prediction (MVP) norms for the Immediate Postconcussion Assessment and Cognitive Testing (ImPACT).

METHODS

We developed the CARE-MVP norms for ImPACT composite scores using regression-based equations. Predictor variables included sex, race (white/Caucasian, black/African American, Asian, or Multiple Races), medical history [attention-deficit/hyperactivity disorder (ADHD), learning disorder (LD), prior concussion(s), prior psychiatric diagnosis], and an estimate of premorbid intellect (Wechsler Test of Adult Reading). CARE-MVP norms were first validated in an independent sample of healthy collegiate athletes by comparing predicted and actual baseline test scores using independent-samples t-tests and Cohen's d effect sizes. We then evaluated base rates of low scores in athletes self-reporting ADHD/LD (vs. non-ADHD/LD) and black/African American race (vs. white/Caucasian) across multiple normative reference methods (Chi square, Cramer's V effect size). Lastly, we validated the CARE-MVP norms in a concussed sample (dependent samples t test, Cohen's d effect size).

RESULTS

A total of 5233 collegiate athletes (18.8 ± 1.2 years, 70.5% white/Caucasian, 39.1% female) contributed to the CARE-MVP norms (development N = 2616; internal validation N = 2617). Race and WTAR score were the strongest and most consistent ImPACT score predictors. There were negligible mean differences between observed and predicted (CARE-MVP) baseline scores (Cohen's d < 0.1) for all ImPACT composite scores except Reaction Time (predicted ~ 20 ms faster than observed, d = - 0.28). Low score base rates were similar for athletes across subpopulations when using CARE-MVP norms (ADHD/LD, V = 0.017-0.028; black/African American, V = 0.043-0.053); while, other normative reference methods resulted in disproportionately higher rates of low scores (ADHD/LD, V = 0.062-0.101; black/African American race, V = 0.163-0.221). Acute (24-48 h) postconcussion ImPACT scores were significantly worse than CARE-MVP norms but notably varied as a function of concussion symptom severity.

CONCLUSIONS

Results support CARE-MVP norm use in populations typically underrepresented or not adjusted for in traditional normative reference samples, such as those self-reporting ADHD/LD or black/African American race. CARE-MVP norms improve upon prior normative methods and may offer a practical, simple alternative for collegiate institutions concerned about logistical and financial burden associated with baseline testing. An automated scoring program is provided.

A Within-Subjects Comparison of Clinical Outcomes for Patients' First and Second Concussions

OBJECTIVES

To examine the difference between an individual's first and second concussion using a comprehensive, multidomain assessment including symptoms, neurocognitive, vestibular, ocular, and individual demographic and medical history risk factors associated with protracted recovery.

SETTING

Concussion Specialty Clinic.

PARTICIPANTS

Seventy-three patients (aged 13-21 years; 57% female) diagnosed with 2 separate concussions (380.5 ± 278.7 days between injuries) from August 2016 to August 2018.

DESIGN

Retrospective within-subjects cohort study.

MAIN MEASURES

ImPACT, PCSS, and Vestibular-Ocular Motor Screen (VOMS) at each visit. Patients were divided into "normal" (≤30 days) and "protracted" recovery (>30 days) for χ2 analyses.

RESULTS

There were no differences between the first and second injuries in recovery time, VOMS, visual and verbal memory, or reaction time. Visual motor speed scores were higher at the second injury time point and reported sleep symptoms were higher at the first injury time point. In addition, participants reported to the clinic on average 3 days earlier for an evaluation for their second injury. Results from χ2 analyses indicated that female sex predicted protracted recovery (>30 days) from concussion at the first injury time point (OR = 4.1; 95% CI, 1.5-11.6; P = .006).

CONCLUSIONS

The findings provide preliminary evidence that there is no clinical difference between patients' first and second concussions when both injuries were treated through a concussion specialty clinic.

Neuropsychological Assessment of Sport-Related Concussion

Neuropsychological assessment is a key component in a comprehensive, multidisciplinary approach to assessment of sport-related concussion (SRC). Currently computerized tests are the most commonly used modality of neurocognitive testing and involve both baseline and postinjury assessments. A comprehensive neuropsychological assessment should not only include neurocognitive testing but also incorporate symptom inventories, vestibular-ocular screening, and a psychological evaluation. Neuropsychological assessments are most effective when completed by a Clinical Neuropsychologist, given their specialized training in test interpretation and conceptualization of the psychological, cognitive, behavioral, physiologic, as well as neurologic principals when treating and managing SRC.

Considerations for Athlete Retirement After Sport-Related Concussion

The recommendation to retire from sport after concussion has evolved with the understanding of concussion. Age, sport, position, level of play, relevant medical and concussion history, severity and duration of symptoms, neuroimaging and neuropsychological testing should all be considered. Susceptibility to injury, persistence of symptoms, psychological distress, and personal values and support may also play a role. Pediatric athletes may require a more conservative approach, given ongoing growth and development. For professional and/or elite athletes, financial or career implications may be considerations. When possible, retirement should be a shared decision among the athlete, the family, and the health care team.

Assessing the Long-Term Impact of Concussion upon Cognition: A 5-Year Prospective Investigation

OBJECTIVE

Jockeys have high rates of concussion, with 5% of jockeys receiving at least one concussion annually. The impact of acute concussion upon cognition is well understood, but less is known about the long-term effects of concussion upon cognition. Our aim was to assess the impact of concussion upon jockeys who had provided pre-concussion assessments of cognition using a prospective design.

METHOD

In this study, over a 5-year period, we assessed the cognitive performance of jockeys with ≥1 medically diagnosed concussion (MDC; n = 17, months since concussion, M = 29.18), against those who had not been concussed (NC; n = 41). Jockeys who had not been concussed in the preceding 6 months completed four computer-based cognitive assessments from the CogSport battery.

RESULTS

Unlike the majority of the small existing literature, there was no difference (p ≥ .05) between the MDC and NC groups after controlling for age and baseline performance. Additionally, we used a measure of reliable change to assess for clinically meaningful decrements from baseline in each test and composite score 5 years later. None of the jockeys in the MDC group recorded significant decrements on any CogSport measure from baseline (z > -1.65).

CONCLUSIONS

The findings suggest that the presence of concussion does not result in persistent decrements in cognitive performance and that when findings are considered collectively, assessing factors beyond medically diagnosed concussion (e.g., chronic stress, undiagnosed concussion) may improve the interpretation of our current findings.

Factors influencing recovery from mild traumatic brain injury

PRIMARY OBJECTIVE

This study determined whether initial GCS score, head CT results, cognitive performance on IMPACT testing, or APOE genotype most effectively predicted 1-month functional outcome after mild traumatic brain injury (mTBI). This study tested the hypotheses that participants with poor performance on initial cognitive testing and those with an APOEe4 genotype would exhibit a poorer 1-month recovery after mTBI.

RESEARCH DESIGN

Regression analysis determined which independent variables were most effective in predicting 1-month GOS-E or DRS score. Independent t-test procedures determined whether cognitive recovery varied across APOEe4 carriers.

METHODS AND PROCEDURES

49 participants admitted to the hospital with mTBI received cognitive evaluation within 48 hours after injury and again one month later. DNA analysis provided participant APOE genotype.

MAIN OUTCOMES AND RESULTS

Results showed that no study variables significantly predicted GOS-E or DRS scores, however, differences were identified when APOE groups were compared. Participants who were noncarriers of APOEe4 had significantly slower reaction times compared to APOEe4 carriers. Participants who were homozygous APOEe4 carriers had significantly lower instances of impulsivity than noncarriers.

CONCLUSIONS

Further research is needed to understand how APOE allele status and performance on initial cognitive testing may influence short-term recovery after mTBI.

Functional magnetic resonance imaging study of working memory several years after pediatric concussion

PRIMARY OBJECTIVE

The neurophysiological effects of pediatric concussion several years after injury remain inadequately characterized. The objective of this study was to determine if a history of concussion was associated with BOLD response differences during an n-back working memory task in youth.

RESEARCH DESIGN

Observational, cross-sectional.

METHODS AND PROCEDURES

Participants include 52 children and adolescents (M = 15.1 years, 95%CI = 14.4-15.8, range = 9-19) with past concussion (n = 33) or orthopedic injury (OI; n = 19). Mean time since injury was 2.5 years (95%CI = 2.0-3.0). Measures included postconcussion symptom ratings, neuropsychological testing, and blood-oxygen-dependent-level (BOLD) functional magnetic resonance imaging (fMRI) during an n-back working memory task.

MAIN OUTCOMES AND RESULTS

Groups did not differ on accuracy or speed during the three n-back conditions. They also did not differ in BOLD signal change for the 1- vs. 0-back or 2- vs. 0-back contrasts (controlling for task performance).

CONCLUSIONS

This study does not support group differences in BOLD response during an n-back working memory task in youth who are on average 2.5 years post-concussion. The findings are encouraging from the perspective of understanding recovery after pediatric concussion.

If Not Now, When? An Absence of Neurocognitive and Postural Stability Deficits in Collegiate Athletes with One or More Concussions

A history of concussion has been associated with decreased neurocognitive function and postural control. The purpose of our study was to compare neurocognitive function and postural control in collegiate athletes with and without varying histories of concussion. Collegiate athletes were divided into groups based on 0 (n = 129), 1 (n = 91), 2 (n = 52), and 3+ (n = 34) prior concussions. Participants in each group were carefully matched by sport, sex, height, weight, and age. Athletes were administered the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT™) and the Sensory Organization Test (SOT) as part of a standard of care pre-season assessment. Group ImPACT (Verbal and Visual Memory, Visual Motor Speed, and Reaction Time) and SOT (Equilibrium Score and Somatosensory, Visual, and Vestibular sensory ratios) outcome scores were compared using one-way analyses of variance (ANOVAs). Coefficients of variation (CVs) were also calculated for each outcome score and were compared using two-sample tests with 95% confidence intervals (CIs). Participants with and without a history of concussion were not significantly different for any ImPACT or SOT outcome score (p's > 0.10). Groups (0, 1, 2, and 3+ previous concussions) were not different from each other for any ImPACT or SOT outcome score (p's ≥ 0.11). Likewise, the CVs associated with each ImPACT and SOT outcome score did not vary significantly between outcome scores for any group comparison (p ≥ 0.09). Our findings suggest that a history of one or more concussions does not influence neurocognitive performance or postural stability in collegiate athletes at their pre-season baseline assessment.

Long-term negative emotional outcomes of warzone TBI

OBJECTIVE

Many veterans of the Iraq and Afghanistan Wars have experienced traumatic brain injury (TBI). Although prior work has examined associations between TBI and development of psychiatric syndromes, less is known about associations between TBI and component emotions constituting these syndromes, especially in the long term. The purpose of this study was to examine the long-term emotional consequences of deployment-related TBI.

METHODS

As part of VA Cooperative Studies Program #566, we assessed a sample of n = 456 US Army soldiers prior to an index deployment to Iraq, and again an average of 8.3 years (SD = 2.4 years) after their deployment for a long-term follow-up assessment. In this report, we used adjusted regression analyses to examine the relationship of deployment TBI to depression, anxiety, and stress symptom severity measured at the long-term follow-up assessment. A structured interview was used to determine TBI history; the Depression, Anxiety, and Stress Scale, 21-item version (DASS-21) was used to determine emotional status at the follow-up evaluation.

RESULTS

Warzone TBI events, particularly when greater than mild in severity, were independently associated with depression, anxiety, and stress severity at long-term follow-up, even after taking into account variance attributable to pre-deployment emotional distress and war-zone stress. Post-hoc analyses did not detect independent associations of either number of events or injury mechanism with outcomes.

CONCLUSIONS

These findings highlight the potentially enduring and multi-faceted emotional effects of deployment TBI, underscoring the need for early assessment of negative affectivity in warzone veterans reporting TBI.

Neuropsychological Assessment of Professional Ice Hockey Players: A Cross-Cultural Examination of Baseline Data Across Language Groups

Objective

Neuropsychological testing in sports has become routine across all levels of play. The National Hockey League (NHL) has conducted baseline neuropsychological assessment of all players since 1997. This study seeks to examine baseline differences among linguistically and culturally diverse groups within the NHL and to present comprehensive normative data for these groups.

Method

Baseline data were obtained from 3,145 professional hockey players’ baseline symptom reporting, neuropsychological test performance on a battery of traditional “paper and pencil” measures, and self-reported concussion history. In addition, 604 baseline post-injury paper and pencil evaluations were conducted the season following a concussion and 4,780 computerized baseline ImPACT administrations were obtained following the introduction of computerized testing.

Results

Normative data for paper and pencil tests and ImPACT are presented for the major language groups within the league: English, French, Swedish, Russian, Czech, Finnish, and German (ImPACT only). It was found that symptom reporting, the number of concussions sustained, and neuropsychological test results vary significantly based on a players’ language of origin. This variability was also present when players were tested in their language of origin.

Conclusions

This study provides insight into the significant baseline differences that exist among NHL players regarding symptoms, concussion history, and cognitive functioning. The findings are discussed with respect to the evaluation and management of NHL players who sustain concussion and more generally in the context of neuropsychological assessment in cross-cultural settings, including the importance of examining neuropsychological functioning using culturally specific norms.

Differential Effect of Recurrent Concussions on Symptom Clusters in Sport Concussion Assessment Tool

CONTEXT

Symptom checklist in Sport Concussion Assessment Tool has been widely used in preseason assessment and in concussion diagnosis, but the impact of prior concussions on the graded symptoms after a new concussion has not been evaluated.

OBJECTIVE

This study was undertaken to examine reported symptoms associated with recurrent concussions using data of a comprehensive survey among athletes.

DESIGN

Retrospective survey and cross-sectional study.

SETTING

College athletes.

PARTICIPANTS

Student athletes who sustained one or more concussions.

MAIN OUTCOME MEASURES

Concussion history and graded symptoms of the most recent concussion at time of the survey were surveyed. The impact of prior concussions was examined over symptoms and aggregated symptoms.

RESULTS

Multiple concussions were associated with greater reporting of individual symptoms related to emotion and physical symptoms of sensitivity to light and noise: more emotional (z = 2.3, P = .02); sadness (z = 2.4, P = .02); nervousness (z = 2.4, P = .02); irritability (z = 3.6, P = .01); sensitivity to light (z = 2.6, P = .01); and sensitivity to noise (z = 2.4, P = .04). The composite scores of emotional symptom and sensitivity symptom clusters were significantly higher: t = 2.68 (P < .01) and t = 3.35 (P < .01), respectively.

CONCLUSIONS

The significant rises in emotional and sensitivity symptoms may be an important additive effect of concussive injury. Closer attention should be given to these symptom clusters when evaluating concussion injury and recovery.

Remote concussion history does not affect visually-guided reaching in young adult females

Aim:

We examined the long-term effects of concussions in young adult females on visuomotor behavior during a visually-guided reaching task of various complexities.

Materials & methods:

20 females with a history of longer than 6 months since a concussion and 20 healthy females quickly and accurately performed a delayed reach to a previously cued target.

Results:

As both cognitive and motor load increased, task performance decreased for both groups (p < 0.05). However, contrary to our primary hypothesis, no differences in task performance were found between the two experimental groups (p > 0.05).

Conclusion:

The young adult females with a remote history of concussion demonstrated no deficits in visuomotor behavior on an attention-mediated reaching task as compared with control participants.

Current literature is inconclusive regarding the long-term effects of concussion. Some have argued that the differing results are due to many uncontrolled factors in study design. In this study, 20 females with a history of concussion more than 6 months ago and 20 healthy females performed a reaching task under different levels of difficulty. As the reaching task got harder, both groups had greater difficulty doing the task quickly and accurately (p < 0.05). Surprisingly, however, no differences in reaching performance existed between the two groups (p > 0.05). Young adult females with a remote history of concussion demonstrated no greater problems with complicated reaching tasks when compared with control participants when experimental conditions are tightly controlled.

Neuropsychological Performance and Subjective Symptom Reporting in Military Service Members With a History of Multiple Concussions: Comparison With a Single Concussion, Posttraumatic Stress Disorder, and Orthopedic Trauma

OBJECTIVE

To examine differences in objective neurocognitive performance and subjective cognitive symptoms in individuals with a history of a single concussion, multiple concussions, orthopedic injuries, and posttraumatic stress disorder (PTSD).

METHOD

Participants included 116 military service members who sustained a mild traumatic brain injury (mTBI) during combat deployment. Subjects were subdivided into groups based on concussion frequency: a single concussion (n = 42), 2 concussions (n = 21), and 3 or more concussions (n = 53). Eighty-one subjects sustained an orthopedic injury (n = 60) during deployment or were diagnosed with PTSD (n = 21), but had no history of mTBI. Subjects completed a battery of neuropsychological tests and self-report measures of postconcussive symptoms, PTSD symptoms, and psychopathology.

RESULTS

No differences were found among the concussion groups on a composite neuropsychological measure. The PTSD group had the highest number of symptom complaints, with the 2-concussion and 3-plus-concussion groups being most similar to the PTSD group. The concussion groups showed a nonsignificant pattern of increasing distress with increasing number of concussions.

CONCLUSIONS

The current findings are consistent with meta-analytic results showing no differential effect on neuropsychological functioning due to multiple concussions. Results also support the burden of adversity hypothesis suggesting increasing symptom levels with increasing psychological or physically traumatic exposures.

Gender Differences in Symptom Reporting on Baseline Sport Concussion Testing Across the Youth Age Span

Background

Little is known regarding gender differences in concussion symptom reporting developmentally across the age span, specifically in pre-adolescent athletes. The present study asks: Do boys and girls differ in symptom reporting across the pre-adolescent to post-adolescent age span?

Method

This retrospective study utilized baseline assessments from 11,695 10-22 year-old athletes assigned to 3 independent groups: Pre-adolescent 10-12 year olds (n = 1,367; 12%), Adolescent 13-17 year olds (n = 2,974; 25%), and Late Adolescent 18-22 year olds (n = 7,354; 63%). Males represented 60% of the sample. Baseline ImPACT composite scores and Post-Concussion Symptom Scale scores (Total, Physical, Cognitive, Emotional, Sleep) were analyzed for the effects of age and gender.

Results

Statistically significant main effects were found for age and gender on all ImPACT composites, Total Symptoms, and Symptom factors. Significant interaction effects were noted between age and gender for all ImPACT composites, Total Symptoms, and Symptom factors. Total Symptoms and all Symptom factors were highest in adolescents (ages 13-17) for males and females. In the 10-12 age group, females displayed lower Total Symptoms, Physical, and Sleep factors than males.

Conclusion

The notion of females being more likely than males to report symptoms does not appear to apply across the developmental age span, particularly prior to adolescence. Females show greater emotional endorsement across the youth age span (10-22 years). Adolescence (13-17 years) appears to be a time of increased symptomatology that may lessen after the age of 18.

An Investigation of Dynamic Cerebral Autoregulation in Adolescent Concussion

PURPOSE

Although cerebrovascular impairments are believed to contribute to concussion symptoms, little information exists regarding brain vasomotor control in adolescent concussion, particularly autoregulatory control that forms a fundamental response mechanism during changes in blood pressure. This research tested the hypothesis that adolescent concussion is marked by impaired dynamic cerebral autoregulation.

METHODS

Nineteen concussed adolescents (15 ± 2 yr, 13 females) and 18 healthy controls (15 ± 2 yr, 9 females) completed two sit-to-stand trials. Brachial artery blood pressure and cerebral blood flow velocity in the right middle cerebral artery were measured continuously. Dynamic rate of regulation was calculated as the rate of change in cerebrovascular resistance relative to the change in arterial blood pressure. The concussed adolescents were followed through their rehabilitation for up to 12 wk.

RESULTS

At the first visit, the concussed adolescents demonstrated reduced rate of regulation compared with the healthy controls (0.12 ± 0.04 vs 0.19 ± 0.06 s, P ≤ 0.001). At the concussed adolescents final visit, after symptom resolution, the rate of regulation improved to levels that were not different from the healthy controls (n = 9; 0.15 ± 0.08 vs 0.19 ± 0.06 s, P= 0.06). Two distinct groups were observed at the final visit with some individuals experiencing recovery of dynamic cerebral autoregulation and others showing no marked change from the initial visit.

CONCLUSION

Adolescents demonstrate an impairment in dynamic cerebral autoregulation after concussion that improves along with clinical symptoms in some individuals and remains impaired in others despite symptom resolution.

Preliminary normative study of ImPACT® in Finnish professional male ice hockey players

Assessment of cognition is an important part of concussion management. The common paradigm of baseline and postinjury evaluations is recommended but due to the often lacking baseline data, reliable normative values are needed. The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®) battery is a widely used method of cognitive assessment offering several language options. There are few comparative studies between language groups on this test battery. ImPACT was administered at baseline to 184 Finnish male Professional Ice Hockey league players. The performance of the Finnish sample differed from previously published English and Czech language samples on the Visual Motor Speed and Reaction Time composites with medium effect-sizes (d = 0.38-0.52). Age, but not education or prior concussions, was associated with ImPACT performance. ImPACT performance is not uniform across language and culture groups and the findings highlight the need for language-specific norms. Finnish reference values for ImPACT for ages <20, 20-26, and >26 are presented. A similar approach is encouraged for other languages.

Wrestling with uncertainty after mild traumatic brain injury: a mixed methods study

Purpose: Our objective was to explore the intersection between mild traumatic brain injury (MTBI) recovery experiences and injury understandings, using both quantitative and qualitative methods.Materials and Methods: The quantitative component was a descriptive case-control study comparing participants (n = 76) who had recovered or not recovered after an MTBI, across demographic and psychological variables. A subset of participants (n = 10) participated in a semi-structured interview to explore experiences of recovery in more detail. We followed threads across the datasets to integrate findings from component methods.Results: The quantitative analyses revealed differences between the two groups in terms of injury recovery understandings and expectations. The qualitative analyses suggested that achieving consistency across information sources was important. By tracing threads back and forth between the component datasets, we identified a super-ordinate meta-theme that captured participants' experiences of wrestling with uncertainty about their recovery and the impacts in terms of heightened anxiety, confusion, and feelings of invalidation.Conclusion: The effectiveness of psychoeducation and reassurance after MTBI may be optimized when content is tailored to the individual. Clinicians are urged to attend both to the subjective interpretations patients make of information gained from formal and informal, internal and external sources, and where information across these sources conflicts and creates uncertainty.Implications for rehabilitationEffectiveness of psychoeducation and reassurance after injury may be optimized when content is tailored to the individual rather than being generic.Effectiveness of such interventions may also be optimized by understanding the subjective interpretations individuals make of injury knowledge gleaned from formal and informal, internal and external sources.Conflicting information from such multiple sources may create uncertainty with associated increased distress as an individual negotiates their recovery from injury. Attending to this uncertainty may be a helpful target for treatment.

Mild Traumatic Brain Injury Burden Moderates the Relationship Between Cognitive Functioning and Suicidality in Iraq/Afghanistan-Era Veterans

OBJECTIVES

Suicidal ideation (SI) is highly prevalent in Iraq/Afghanistan-era veterans with a history of mild traumatic brain injury (mTBI), and multiple mTBIs impart even greater risk for poorer neuropsychological functioning and suicidality. However, little is known about the cognitive mechanisms that may confer increased risk of suicidality in this population. Thus, we examined relationships between neuropsychological functioning and suicidality and specifically whether lifetime mTBI burden would moderate relationships between cognitive functioning and suicidal ideation.

METHODS

Iraq/Afghanistan-era Veterans with a history of mTBI seeking outpatient services (N = 282) completed a clinical neuropsychological assessment and psychiatric and postconcussive symptom questionnaires.

RESULTS

Individuals who endorsed SI reported more severe post-traumatic stress disorder (PTSD), depression, and postconcussive symptoms and exhibited significantly worse memory performance compared to those who denied SI. Furthermore, mTBI burden interacted with both attention/processing speed and memory, such that poorer performance in these domains was associated with greater likelihood of SI in individuals with a history of three or more mTBIs. The pattern of results remained consistent when controlling for PTSD, depression, and postconcussive symptoms.

CONCLUSIONS

Slowed processing speed and/or memory difficulties may make it challenging to access and use past experiences to solve current problems and imagine future outcomes, leading to increases in hopelessness and SI in veterans with three or more mTBIs. Results have the potential to better inform treatment decisions for veterans with history of multiple mTBIs. (JINS, 2019, 25, 79-89).

Psychological Resilience as a Predictor of Persistent Post-Concussive Symptoms in Children With Single and Multiple Concussion

OBJECTIVES

To evaluate the relationship of psychological resilience to persistent post-concussive symptoms (PCS) in children with a history of single or multiple concussions, as well as orthopedic injury (OI).

METHODS

Participants (N=75) were children, ages 8-18 years, who sustained a single concussion (n=24), multiple concussions (n=25), or an OI (n=26), recruited from a tertiary care children's hospital. All participants sustained injuries at least 6 months before recruitment, with an average time since injury of 32.9 months. Self-reported psychological resilience was measured using the Connor-Davidson Resilience Scale, and both self- and parent-reported PCS were measured using the Post-Concussion Symptom Inventory. Hierarchical regression analyses examined psychological resilience as a predictor of PCS, both as a main effect and as a moderator of group differences.

RESULTS

Multiple concussions and low psychological resilience were both significant predictors of persistent PCS. Resilience was not a significant moderator of group differences in PCS.

CONCLUSIONS

Sustaining multiple concussions may increase a child's risk of persistent PCS; however, high psychological resilience may serve as a protective factor, regardless of the number or type of injuries sustained. These findings provide support for developing and testing interventions aimed at increasing psychological resilience as a potential means of improving outcomes for children suffering from persistent PCS after concussion. (JINS, 2018, 24, 759-768).

Influences of Mental Illness, Current Psychological State, and Concussion History on Baseline Concussion Assessment Performance

BACKGROUND

A student-athlete's mental state, including history of trait anxiety and depression, or current psychological state may affect baseline concussion assessment performance.

PURPOSE

(1) To determine if mental illness (anxiety, depression, anxiety with depression) influences baseline scores, (2) to determine if psychological state correlates with baseline performance, and (3) to determine if history of concussion affects Brief Symptom Inventory-18 (BSI-18) subscores of state anxiety, depression, and somatization.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A sample of 8652 collegiate student-athletes (54.5% males, 45.5% females) participated in the Concussion Assessment, Research and Education (CARE) Consortium. Baseline assessments included a demographic form, a symptom evaluation, Standardized Assessment of Concussion, Balance Error Scoring System, a psychological state assessment (BSI-18), and Immediate Post-concussion Assessment and Cognitive Test. Baseline scores were compared between individuals with a history of anxiety (n = 59), depression (n = 283), and anxiety with depression (n = 68) and individuals without a history of those conditions (n = 8242). Spearman's rho correlations were conducted to assess the relationship between baseline and psychological state subscores (anxiety, depression, somatization) (α = .05). Psychological state subscores were compared between individuals with a self-reported history of concussions (0, 1, 2, 3, 4+) using Kruskal-Wallis tests (α = .05).

RESULTS

Student-athletes with anxiety, depression, and anxiety with depression demonstrated higher scores in number of symptoms reported (anxiety, 4.3 ± 4.2; depression, 5.2 ± 4.8; anxiety with depression, 5.4 ± 3.9; no anxiety/depression, 2.5 ± 3.4), symptom severity (anxiety, 8.1 ± 9.8; depression, 10.4 ± 12.4; anxiety with depression, 12.4 ± 10.7; no anxiety/depression, 4.1 ± 6.9), and psychological distress in state anxiety (anxiety, 3.7 ± 4.7; depression, 2.5 ± 3.6; anxiety with depression, 3.8 ± 4.2; no anxiety/depression, 0.8 ± 1.8), depression (anxiety, 2.4 ± 4.0; depression, 3.2 ± 4.5; anxiety with depression, 3.8 ± 4.8; no anxiety/depression, 0.8 ± 1.8), and somatization (anxiety, 2.3 ± 2.9; depression, 1.8 ± 2.8; anxiety with depression, 2.2 ± 2.4; no anxiety/depression, 0.9 ± 1.7). A moderate positive relationship existed between all BSI-18 subscores and total symptom number (n = 8377; anxiety: r_s = 0.43, P < .001; depression: r_s = 0.42, P < .001; somatization: r_s = 0.45, P < .001), as well as total symptom severity (anxiety: r_s = 0.43, P < .001; depression: r_s = 0.41, P < .001; somatization: r_s = 0.45, P < .001). Anxiety, depression, and somatization subscores were greater among student-athletes that self-reported more concussions.

CONCLUSION

Clinicians should be cognizant that student-athletes with a history of trait anxiety, depression, and anxiety with depression may report higher symptom score and severity at baseline. Individuals with extensive concussion history may experience greater state anxiety, depression, and somatization.

Postconcussive Symptoms After Single and Repeated Concussions in 10- to 20-Year-Olds: A Cross-Sectional Study

The objective was to characterize cognitive deficits and postconcussive symptoms in a pediatric population with no concussion, a single concussion, and ≥2 concussions, using a cross-sectional design. Cognitive function and postconcussive symptoms were assessed in participants (age 10-20) with no concussion (n = 1118), single concussion (n = 368), and repeated (≥2) concussions (n = 252). Analyses were adjusted for age and gender. Individuals with ≥2 concussions exhibited more total postconcussive symptoms; more loss of consciousness, amnesia and confusion; more headaches; and poorer cognitive function compared to no concussion and single concussion. Postconcussive symptoms may play a modulatory role in cognitive dysfunction after repeated concussions as those with loss of consciousness, amnesia, confusion, or headaches exhibited worse verbal memory, visual memory, visual-motor processing, and poorer impulse control compared to those without these symptoms. This analysis demonstrates that repeated concussions is associated with poorer cognitive function and postconcussive symptoms compared to a single concussion.

Effects of concussions on visually guided motor actions: A literature review

Athletes must be able to successfully navigate the soccer pitch or hockey rink to win the game, requiring maximal cognitive resources to successfully compete. Concussions potentially deplete these resources, and the long-term impact of concussions on an individual's goal-directed visually guided behavior continues to elude the scientific community. While the acute effects on cognition and the motor system have been elucidated elsewhere, long-term effects on performance have been less clear. Additionally, most investigations into long-term postinjury motor behaviors have focused on balance and gait, with little focus on functional upper extremity movements. These arm movements require both cognitive and motor functions to successfully complete the task, such as visually guided reaching, and have received little attention. This review examines the current state of the literature to date on the long-term effects of concussions on cognitive and motor deficits affecting visuomotor behavior.

Investigating Effects of Sex Differences and Prior Concussions on Symptom Reporting and Cognition Among Adolescent Soccer Players

BACKGROUND

There has been increasing concern regarding the possible effect of multiple concussions on the developing brain, especially for adolescent females. Hypothesis/Purpose: The objectives were to determine if there are differences in cognitive functioning, symptom reporting, and/or sex effects from prior concussions. In a very large sample of youth soccer players, it was hypothesized that (1) there would be no differences in cognitive test performance between those with and without prior concussions, (2) baseline preseason symptoms would be better predicted by noninjury factors than concussion history, and (3) males and females with prior concussions would not have differences in cognition or symptoms.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Participants included 9314 youth soccer players (mean = 14.8 years, SD = 1.2) who completed preseason baseline cognitive testing, symptom reporting, and a health/injury history questionnaire from the ImPACT battery (Immediate Post-concussion Assessment and Cognitive Testing). On the basis of injury history, athletes were grouped by number of prior concussions: 0 (boys, n = 4012; girls, n = 3963), 1 (boys, n = 527; girls, n = 457), 2 (boys, n = 130; girls, n = 97), or ≥3 (boys, n = 73; girls, n = 55). The primary measures were the 4 primary cognitive scores and the total symptom ratings from ImPACT. Primary outcomes were assessed across injury groups, controlling for age, sex, learning disability, attention-deficit/hyperactivity disorder (ADHD), treatment for headaches/migraines, substance abuse, and mental health problems.

RESULTS

Cognitive test performance was not associated with concussion history but was associated with sex, age, learning disability, ADHD, and prior mental health problems. Greater symptom reporting was more strongly associated with psychiatric problems, older age, learning disability, substance abuse, headaches, being female, and ADHD than with a history of multiple concussions. Boys and girls did not differ on cognitive scores or symptom reporting based on a history of concussion.

CONCLUSION

In this very large sample of youth soccer players with prior concussion, there was no evidence of negative effects on cognition, very weak evidence of negative effects on symptom reporting, and no evidence of sex × concussion differences in cognition or symptom reporting.

MRI Evidence of Neuropathic Changes in Former College Football Players

OBJECTIVE

To examine effects of participating in collegiate football on neural health several years after retirement. We hypothesized that relative cortical thinning and loss of white matter integrity would be observed in former players.

DESIGN

Former NCAA Division I football players were compared with demographically similar track-and-field athletes with regard to cortical thickness and white matter integrity.

SETTING

Participants participated in MRI scans at the Center for Imaging Research at the University of Cincinnati.

PARTICIPANTS

Eleven former football players and 10 demographically similar track-and-field athletes.

MAIN OUTCOME MEASURES

Normalized cortical thickness was compared between groups using 2-tailed Student t test. As a secondary analysis, Spearman correlation coefficient was calculated between cortical thickness and number of concussions. Fractional anisotropy for regions-of-interest placed in frontal white matter tracts and internal capsule were compared between groups using 2-tailed Student t test.

RESULTS

Football players showed significantly lower cortical thickness within portions of both the frontal and temporal cortex. Affected frontal regions included left frontal pole and right superior frontal gyrus. Affected temporal regions included portions of the superior temporal gyrus, left inferior temporal gyrus, and right middle and superior temporal gyri. Cortical thickness inversely correlated with number of reported concussions over most of these regions. In addition, fractional anisotropy was lower in the right internal capsule of former football players, relative to controls.

CONCLUSIONS

These findings suggest that at least some consequences of high-level collegiate football play persist even after the cessation of regular head blows. Longer-term studies are warranted to examine potential cognitive and functional implications of sustained cortical atrophy.

Sport Concussion and the Female Athlete

Sport concussion (SC) has emerged as a major health concern in the medical community and general public owing to increased research and media attention, which has primarily focused on male athletes. Female athletes have an equal, if not increased, susceptibility to SC. An ever-growing body of research continues to compare male and female athletes in terms of SC before and after an injury. Clinicians must be cognizant of this literature to make evidence-based clinical decision when providing care to female athletes and discern between dated and/or unsupported claims in terms of SC.

Long-term effects of sport concussion on cognitive and motor performance: A review

Motor and cognitive dysfunction is intractable sequela in the acute stage of concussion. While typical concussion recovery occurs in two weeks, empirical evidence suggests that some sequela persist beyond this period, though there is inconsistency surrounding the duration the sequela persist. In part, confusion around the issue is limited by the volume of literature evaluating those with a concussion history, permitting vast interpretations of significance. The purpose of this paper is to review the concussion history literature, summarizing the long-term effects of concussion history on motor and cognitive performance. Additionally, this review intends to provide direction and options of future investigations addressing the long-term effects of concussion on motor and cognitive performance.

Neurometabolic indicators of mitochondrial dysfunction in repetitive mild traumatic brain injury

Mild traumatic brain injury (mTBI) is a significant national health concern and there is growing evidence that repetitive mTBI (rmTBI) can cause long-term change in brain structure and function. The mitochondrion has been suggested to be involved in the mechanism of TBI. There are noninvasive methods of determining mitochondrial dysfunction through biomarkers and spectroscopy. Mitochondrial dysfunction has been implicated in a variety of neurological consequences secondary to rmTBI through activation of caspases and calpains. The purpose of this review is to examine the mechanism of mitochondrial dysfunction in rmTBI and its downstream effects on neuronal cell death, axonal injury and blood–brain barrier compromise.

Adult cognitive outcomes following childhood mild traumatic brain injuries

OBJECTIVE

To investigate the adult cognitive outcomes of one versus multiple childhood mTBI and to examine the potential predictors of the outcomes.

METHODS

Review of neurosurgical files and hospital records, as well as community recruitment, yielded 169 participants, who were injured between ages 0-17 years and assessed between ages 18-30 years with at least five years post-injury. Each participant underwent a three-hour assessment. For data analysis, participants were grouped by type and number of injury.

RESULTS

The mTBI group exhibited some cognitive deficits but their performance fell between the control and moderate/severe TBI groups as expected. Those with one and multiple mTBI performed comparably across all cognitive domains. Cognitive outcomes were significantly predicted by estimated IQ but not by number of mTBI and age at injury.

CONCLUSION

Despite the detected cognitive deficits, those who sustained multiple mTBI did not exhibit worse or cumulative deficits compared to those with one mTBI.

Cumulative Effects of Concussion History on Baseline Computerized Neurocognitive Test Scores: Systematic Review and Meta-analysis

Context:

It is unclear whether individuals with a history of single or multiple clinically recovered concussions exhibit worse cognitive performance on baseline testing compared with individuals with no concussion history.

Objective:

To analyze the effects of concussion history on baseline neurocognitive performance using a computerized neurocognitive test.

Data sources:

PubMed, CINAHL, and psycINFO were searched in November 2015. The search was supplemented by a hand search of references.

Study Selection:

Studies were included if participants completed the Immediate Post-concussion Assessment and Cognitive Test (ImPACT) at baseline (ie, preseason) and if performance was stratified by previous history of single or multiple concussions.

Study Design:

Systematic review and meta-analysis.

Level of Evidence:

Level 2.

Data Extraction:

Sample size, demographic characteristics of participants, as well as performance of participants on verbal memory, visual memory, visual-motor processing speed, and reaction time were extracted from each study.

Results:

A random-effects pooled meta-analysis revealed that, with the exception of worsened visual memory for those with 1 previous concussion (Hedges g = 0.10), no differences were observed between participants with 1 or multiple concussions compared with participants without previous concussions.

Conclusion:

With the exception of decreased visual memory based on history of 1 concussion, history of 1 or multiple concussions was not associated with worse baseline cognitive performance.

Evaluating the test-retest reliability of symptom indices associated with the ImPACT post-concussion symptom scale (PCSS)

OBJECTIVE

The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a commonly used tool in sports concussion assessment. While test-retest reliabilities have been established for the ImPACT cognitive composites, few studies have evaluated the psychometric properties of the ImPACT's Post-Concussion Symptom Scale (PCSS). The purpose of this study was to establish the test-retest reliability of symptom indices associated with the PCSS.

PARTICIPANTS AND METHODS

Participants included 38 undergraduate students (50.0% male) who underwent neuropsychological testing as part of their participation in their psychology department's research subject pool. The majority of the participants were Caucasian (94.7%) and had no history of concussion (73.7%). All participants completed the ImPACT at two time points, approximately 6 weeks apart. The PCSS was the main outcome measure, and eight symptom indices were calculated (a total symptom score, three symptom summary indices, and four symptom clusters).

RESULTS

Pearson correlations (r) and intraclass correlation coefficients (ICCs) were computed as measures of test-retest reliability. Overall, reliabilities ranged from low to high (r = .44 to .80; ICC = .44 to .77). The cognitive symptom cluster exhibited the highest test-retest reliability (r = .80, ICC = .77), followed by the positive symptom total (PST) index, an indicator of the total number of symptoms endorsed (r = .71, ICC = .69). In contrast, the commonly used total symptom score showed lower test-retest reliability (r = .67, ICC = .62). Paired-samples t tests revealed no significant differences between test and retest for any of the symptom variables (all p > .01). Finally, reliable change indices (RCI) were computed to determine whether differences observed between test and retest represented clinically significant change. RCI values were provided for each symptom index at the 80%, 90%, and 95% confidence intervals.

CONCLUSION

These results suggest that evaluating additional symptom indices beyond the total symptom score from the PCSS is beneficial. Findings from this study can be applied to athlete samples to assess reliable change in symptoms following concussion.

Long-Term Cognitive and Neuropsychiatric Consequences of Repetitive Concussion and Head-Impact Exposure

Initially, interest in sport-related concussion arose from the premise that the study of athletes engaged in sports associated with high rates of concussion could provide insight into the mechanisms, phenomenology, and recovery from mild traumatic brain injury. Over the last decade, concerns have focused on the possibility that, for some athletes, repetitive concussions may raise the long-term risk for cognitive decline, neurobehavioral changes, and neurodegenerative disease. First conceptualized as a discrete event with variable recovery trajectories, concussion is now viewed by some as a trigger of neurobiological events that may influence neurobehavioral function over the course of the life span. Furthermore, advances in technology now permit us to gain a detailed understanding of the frequency and intensity of repetitive head impacts associated with contact sports (eg, football, ice hockey). Helmet-based sensors can be used to characterize the kinematic features of concussive impacts, as well as the profiles of typical head-impact exposures experienced by athletes in routine sport participation. Many large-magnitude impacts are not associated with diagnosed concussions, whereas many diagnosed concussions are associated with more modest impacts. Therefore, a full understanding of this topic requires attention to not only the effects of repetitive concussions but also overall exposure to repetitive head impacts. This article is a review of the current state of the science on the long-term neurocognitive and neurobehavioral effects of repetitive concussion and head-impact exposure in contact sports.

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.

Long-term Effects of Adolescent Sport Concussion Across the Age Spectrum

BACKGROUND

Research in sport concussion has increased greatly over the previous decade due to increased scientific interest as well as the media and political spotlight that has been cast on this injury. However, a dearth of literature is available regarding the long-term (>1 year after concussion) effects of adolescent concussion on cognitive and motor performance of high school athletes.

PURPOSE

To evaluate the potential for long-term effects of concussion sustained during high school on cognitive and motor performance across the lifespan.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Adults with (n = 30) and without (n = 53) a concussion history were recruited in 3 age groups: younger (18-30 years; n = 43), middle-aged (40-50 years; n = 18), and older (≥60 years; n = 22). Each participant completed a computerized neurocognitive assessment and continuous tracking and discrete temporal auditory tasks with the hand and foot. Root mean squared error and timing variability were derived from the tracking and temporal auditory tasks, respectively. Data were analyzed by regression analyses for each recorded variable.

RESULTS

The analysis revealed significant age effects on neurocognitive task, continuous tracking task, and discrete auditory timing task performance ( P values < .05). No concussion history or interaction (concussion history by age) effects were found for performance on any task ( P values > .05).

CONCLUSION

While longitudinal investigations are still needed, this cross-sectional study failed to identify any observable effect of adolescent concussion history on cognition or motor performance with age.

A case matched study examining the reliability of using ImPACT to assess effects of multiple concussions

BACKGROUND

Approximately 3.8 million sport and recreational concussions occur per year, creating a need for accurate diagnosis and management of concussions. Researchers and clinicians are exploring the potential dose-response cumulative effects of concussive injuries using computerized neuropsychological exams, however, results have been mixed and/or contradictory. This study starts with a large adolescent population and applies strict inclusion criteria to examine how previous mild traumatic brain injuries affect symptom reports and neurocognitive performance on the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) computerized tool.

METHODS

After applying exclusion criteria and case matching, 204 male and 99 female participants remained. These participants were grouped according to sex and the number of previous self-reported concussions and examined for overall differences on symptoms reported and scores obtained on the ImPACT neurocognitive battery composites. In an effort to further reduce confounding factors due to the varying group sizes, participants were then case matched on age, sex, and body mass index and analyzed for differences on symptoms reported and scores obtained on the ImPACT neurocognitive battery composites.

RESULTS

Case matched analysis demonstrated males with concussions experience significantly higher rates of dizziness (p = .027, η² = .035), fogginess (p = .038, η² = .032), memory problems (p = .003, η² = .055), and concentration problems (p = .009, η² = .046) than males with no reported previous concussions. No significant effects were found for females, although females reporting two concussions demonstrated a slight trend for experiencing higher numbers of symptoms than females reporting no previous concussions.

CONCLUSIONS

The results suggest that male adolescent athletes reporting multiple concussions have lingering concussive symptoms well after the last concussive event; however, these symptoms were found to be conflicting and better explained by complainer versus complacent attitudes in the population examined. Our results conflict with a significant portion of the current literature that uses relatively lenient inclusion and exclusion criteria, providing evidence of the importance of strict inclusion and exclusion criteria and examination of confounding factors when assessing the effects of concussions.

Neuropsychiatric aspects of concussion: acute and chronic sequelae

Concussion – also known as mild traumatic brain injury – is a transient disturbance of neurological function resulting from traumatic forces imparted to the brain that often produce cognitive, behavioral and systemic symptoms. In this review of the literature, we discuss the pathophysiology of both acute and chronic neuropsychiatric sequelae of concussions, followed by a brief overview of evaluation and management of these sequelae.

Sex-Related Differences in Emotion Recognition in Multi-concussed Athletes

OBJECTIVES

Concussion is defined as a complex pathophysiological process affecting the brain. Although the cumulative and long-term effects of multiple concussions are now well documented on cognitive and motor function, little is known about their effects on emotion recognition. Recent studies have suggested that concussion can result in emotional sequelae, particularly in females and multi-concussed athletes. The objective of this study was to investigate sex-related differences in emotion recognition in asymptomatic male and female multi-concussed athletes.

METHODS

We tested 28 control athletes (15 males) and 22 multi-concussed athletes (10 males) more than a year since the last concussion. Participants completed the Post-Concussion Symptom Scale, the Beck Depression Inventory-II, the Beck Anxiety Inventory, a neuropsychological test battery and a morphed emotion recognition task. Pictures of a male face expressing basic emotions (anger, disgust, fear, happiness, sadness, surprise) morphed with another emotion were randomly presented. After each face presentation, participants were asked to indicate the emotion expressed by the face.

RESULTS

Results revealed significant sex by group interactions in accuracy and intensity threshold for negative emotions, together with significant main effects of emotion and group.

CONCLUSIONS

Male concussed athletes were significantly impaired in recognizing negative emotions and needed more emotional intensity to correctly identify these emotions, compared to same-sex controls. In contrast, female concussed athletes performed similarly to same-sex controls. These findings suggest that sex significantly modulates concussion effects on emotional facial expression recognition. (JINS, 2017, 23, 65-77).

Evidence of a conservative gait strategy in athletes with a history of concussions

BACKGROUND

A history of 3 or more concussions is frequently associated with numerous short- and long-term neuropathologies. Impairments in postural control are a known acute consequence of concussion; however, limited evidence exists on the effects of multiple concussions on gait. The purpose of this study was to assess gait stepping characteristics in collegiate aged student-athletes based on concussion history.

METHODS

There were 63 participants divided into 3 even groups based on concussion history: ≥3 concussions, 1-2 concussions, and 0 concussion. All participants completed 10 trials of gait on a 4.9 m instrumented walkway. The dependent variables of interest included both gait stepping characteristics (step velocity, length, and width, double support time, and the percentage of the gait cycle in stance) and coefficient of variability (CoV) measures (step length, time, and width). The gait stepping characteristics were compared first with a MANOVA with follow-up 1-way ANOVAs and Tukey post hoc tests as appropriate. The CoV measures were compared with 1-way ANOVAs and Tukey post hoc tests.

RESULTS

There were main effects for group for step velocity, length, width, and double support time. Overall, the 0 concussion group displayed typical healthy young gait parameters and performed significantly better than either concussion group. The 0 concussion group had a significantly greater step length CoV, but there were no differences in the step time or width CoV.

CONCLUSION

This finding provides evidence of subtle impairments in postural control during gait among individuals with prior history of concussion which could be an early indicator of future neurological deficiencies. The limited difference in the variability measures is consistent with prior static stance studies and could suggest the individuals constrain their motor systems to reduce variability. Taken together, these findings suggest a conservative gait strategy which is adopted by individuals with a history of concussions.