What are the real risks of sport-related concussion, and are they modifiable?

Changes in the central nervous system in football players: an MRI study

BACKGROUND

Football (soccer) is the world's most popular team sport.

PURPOSE

To comprehensively examine the brain in football (soccer) players, with the use of magnetic resonance imaging (MRI) techniques.

MATERIAL AND METHODS

The study involved 65 football players and 62 controls. The MR examinations were performed using MR 1.5-T system (Optima MR 360; GE Medical Systems). The examinations were carried out in the 3D Bravo, CUBE, FSEpropeller, and diffusion-weighted imaging (DWI) sequences. The 1HMRS signal was obtained from the volume of interest in the frontal and occipital lobes on both sides.

RESULTS

The present study, based on structural MRI, shows some changes in the brains of the group of football players. The findings show asymmetry of the ventricular system in four football players, arachnoid cysts in the parieto-occipital region, and pineal cysts. NAA/Cr concentration in the right frontal lobe was lower in the football players than in the controls, and the Glx/Cr concentration in the right occipital lobe was higher. The apparent diffusion coefficient value is lower in football players in the occipital lobes.

CONCLUSION

Playing football can cause measurable changes in the brain, known to occur in patients diagnosed with traumatic brain injury. The present findings fill the gap in the literature by contributing evidence showing that playing football may lead to changes in the brain, without clinical symptoms of concussion.

Neurocognitive outcomes of older National Football League retirees

OBJECTIVE

Determine if head-injury exposure relates to later-in-life cognitive decline in older National Football League (NFL) retirees.

METHOD

NFL retirees (aged 50+) with or without cognitive impairment underwent baseline (n = 53) and follow-up (n = 29; 13-59 months later) neuropsychological evaluations. Cognitively normal (CN) retirees (n = 26) were age- and education-matched to healthy controls (n = 26). Cognitively impaired (CI) retirees with mild cognitive impairment or dementia (n = 27) were matched to a clinical sample (CS) by age, sex, education, and diagnosis (n = 83). ANOVAs compared neuropsychological composites at baseline and over time between retirees and their matched groups. Regression models evaluated whether concussions, concussions with loss of consciousness (LOC), or games played predicted neuropsychological functioning.

RESULTS

At baseline, CN retirees had slightly worse memory than controls (M_{CN retirees} = 50.69, SE_{CN retirees} = 1.320; M_{Healthy controls} = 57.08, SE_{Healthy controls} = 1.345; p = 0.005). No other group diferences were observed, and head-injury exposure did not predict neurocognitive performance at baseline or over time.

CONCLUSIONS

Head-injury exposure was not associated with later-in-life cognition, regardless of cognitive diagnosis. Some retirees may exhibit lower memory scores compared to age-matched peers, though this is of unclear clinical significance.

Epidemiology of female youth ice hockey injuries presenting to United States emergency departments from 2002 to 2019

BACKGROUND

This study documented injury types, rates and mechanisms for female youth ice hockey players reporting to US emergency departments to inform safety measures and sideline medical preparedness.

METHODS

The National Electronic Injury Surveillance System (NEISS) database was queried for ice hockey injuries (product code 1279) from 1 January 2002 to 31 December 2019. Incidence rate ratios (IRR) were calculated using OpenEpi and compared between age divisions. Spearman's rank correlation was utilized to evaluate the correlation between age and injury incidence. USA Hockey membership statistics were used to establish the population at risk and calculate incidence rates (IR).

RESULTS

An estimated 20,384 ice hockey injuries presented to participating United States emergency departments. The number of female youth ice hockey players increased significantly from 36,258 in 2002 to 65,072 in 2019 (p < 0.01). The most commonly injured body parts were the head (n = 5,519, IR = 62.1 [95%CI 54.3-70.0 per 10,000 athletes), trunk (n = 2,364, IR = 26.6 [95%CI 21.2-32.0] per 10,000 athletes), and wrist (n = 1,824, IR = 20.5 [95%CI 15.7-25.4] per 10,000 athletes). The most commonly reported mechanisms of injury were player-to-player collision (n = 4,746, IR = 53.4 [95%CI 46.4-60.5] per 10,000 athletes) and falls (n = 4,585, IR = 51.6 [95%CI 44.1-59.1] per 10,000 athletes). The most common diagnoses were traumatic brain injury (n = 5,333, IR = 60.0 [95%CI 52.3-67.8] per 10,000 athletes), contusion (n = 4,204, IR = 47.3 [95%CI 40.3-54.4] per 10,000 athletes) and strain/sprain (n = 3,601, IR = 40.5 [95%CI 34.1-47.0] per 10,000 athletes). A positive correlation was found between age and injury incidence, as well as increasing age and injuries from player-to-player collision and TBI's.

CONCLUSIONS

Though body checking is illegal at all levels of women's ice hockey, player-to-player collision prevailed as the leading mechanism on injury. Hopefully this study informs players, parents, coaches, trainers and clinicians about the impact of player-to-player collisions on overall injury burden in the older age divisions of youth female hockey.

Brain smart – Let's play safely: Evaluation of a concussion education program in schools

Objectives

There are two objectives for this paper. First, to determine effects of a concussion education program in a local school board in terms of concussion-specific knowledge in children and confidence in identifying and managing concussion in adults. Second, to identify differences and similarities in concussion knowledge between children who participate in sports and those who do not and between children with a history of one or more concussions and those without.

Design

A cross sectional survey regarding concussion knowledge was distributed randomly to students and adults at both pre- and posteducation timepoints. A concussion education program was disseminated across the school board for students between the distribution survey timepoints. Following the education program, adults and students completed their respective post-test surveys. Chi-squared tests in SPSS determined the significance of between-group differences.

Results

All 17 adults (100.0%) who had received concussion education recently reported confidence in their knowledge of concussion management, compared to 35.7% adults who had not received education for over a year (p = 0.020). For students, all of whom completed the concussion education training between the pre- and post-tests, there were no significant differences in concussion knowledge scores between athletes and non-athletes (either in or outside of school) or between those with a history of concussion and those without. There were no significant changes in concussion knowledge between the pre- and post-tests, except for one question.

Conclusion

Concussion education programs increase confidence of concussion management protocols in adults involved in sport, but they require improvements to better support knowledge amelioration, particularly for target groups that are at high risk of sustaining another injury.

The Nocebo Effect and Pediatric Concussion

While placebo effects are well recognized within clinical medicine, "nocebo effects" have received much less attention. Nocebo effects are problems caused by negative expectations derived from information or treatment provided during a clinical interaction. In this review, we examine how nocebo effects may arise following pediatric concussion and how they may worsen symptoms or prolong recovery. We offer several suggestions to prevent, lessen, or eliminate such effects. We provide recommendations for clinicians in the following areas: terminology selection, explicit and implicit messaging to patients, evidence-based recommendations, and awareness of potential biases during clinical interactions. Clinicians should consider the empirically grounded suggestions when approaching the care of pediatric patients with concussion.

Second Impact Syndrome. Myth or reality?

INTRODUCTION

Second impact syndrome (SIS) is a devastating condition occurring in sport-induced mild brain injury. SIS is drastically defined by anamnestic, clinical and radiological criteria, which is unusual in the field of cranial traumatology. The purpose of this study was to provide a literature review of this syndrome.

MATERIAL AND METHODS

We conducted a literature review of all published studies on PubMed. The keywords were "second impact syndrome and catastrophic head injury", "second impact syndrome and sport", "repeat concussion and catastrophic brain injury", "catastrophic head injury and concussion", "catastrophic head injury", "concussion and second impact syndrome", "concussion and repetitive head injury".

RESULTS

Eighty-two full-text articles were assessed for eligibility. Finally, 41 studies were included in qualitative synthesis and 21 were included in quantitative synthesis.

DISCUSSION

The number of cases reported in the literature was extremely small compared to the population at risk, i.e., the number of athletes exposed to repeated concussions. SIS was similar to talk and die syndrome, with which it shares certain characteristics. If we consider SIS according to "talk and deteriorate tables", it opens up interesting perspectives because they are specific in children and adolescents. Taking into account the scarcity of this syndrome, one may question whether athlete-intrinsic features may be involved in at least some cases of SIS. On a pathophysiological level, many explanations remained unsatisfactory because they were unable to explain all the clinical phenomena and observed lesions. Triggering the trigeminocardiac reflex is a crucial element in explaining the sequence of clinical events. Its association with a state of neurogenic inflammation provides an almost complete explanation for this particular condition. Finally, on a practical level, a concussion occurring during the playing of a sport must be considered as any other injury before allowing a return to play.

Concussion: pathophysiology and clinical translation

The majority of the 3.8 million estimated annual traumatic brain injuries (TBI) in the United States are mild TBIs, or concussions, and they occur primarily in adolescents and young adults. A concussion is a brain injury associated with rapid brain movement and characteristic clinical symptoms, with no associated objective biomarkers or overt pathologic brain changes, thereby making it difficult to diagnose by neuroimaging or other objective diagnostic tests. Most concussion symptoms are transient and resolve within 1-2 weeks. Concussions share similar acute pathophysiologic perturbations to more severe TBI: there is a rapid release of neurotransmitters, which causes ionic disequilibrium across neuronal membranes. Re-establishing ionic homeostasis consumes energy and leads to dynamic changes in cerebral glucose uptake. The magnitude and duration of these changes are related to injury severity, with milder injuries showing faster normalization. Cerebral sex differences add further variation to concussion manifestation. Relative to the male brain, the female brain has higher overall cerebral blood flow, and demonstrates regional differences in glucose metabolism, inflammatory responses, and connectivity. Understanding the pathophysiology and clinical translation of concussion can move research towards management paradigms that will minimize the risk for prolonged recovery and repeat injury.

Does a Unique Neuropsychiatric Profile Currently Exist for Chronic Traumatic Encephalopathy?

There is evidence that repetitive mild traumatic brain injury leads to specific patterns of neuropathological findings, labeled chronic traumatic encephalopathy (CTE). However, questions remain about whether these neuropathological changes produce changes in behavior, cognition, and emotional status that are associated with a unique neuropsychiatric profile that can be assessed using currently available clinical tools. Our review of the literature indicates that insufficient evidence currently exists to suggest a distinct neuropsychiatric profile for CTE. Major limitations to the field presently include the relatively nascent nature of the topic, reliance on retrospective next-of-kin reporting, the lack of prospective studies, and similarities in neuropsychiatric symptoms between CTE, other neurodegenerative disorders and forms of psychopathology. Clinicians and researchers alike have a responsibility to adopt a cautious and balanced approach for antemortem assessments to minimize the potential unintended negative consequences of both overdiagnosing and underdiagnosing a clinical entity that has yet to be clearly established.

What Definition Is Used to Describe Second Impact Syndrome in Sports? A Systematic and Critical Review

Concern about what has been termed, "second impact syndrome" (SIS) is a major factor determining return-to-play decisions after concussion. However, definitions of SIS vary. We used Scopus to conduct a systematic review and categorize the definitions used to describe SIS. Of the 91 sources identified, 79 (87%) clearly specified that SIS involved either cerebral edema or death after a concussion when a prior concussion had not resolved. Twelve articles (13%) could be interpreted as merely the events of two consecutive concussions. Among the articles that listed mortality rates, nearly all (33/35, 94%) said the rate of death was "high" (e.g., 50% to 100%). Our review found that most articles define SIS as a syndrome requiring catastrophic brain injury after consecutive concussive episodes. Given that it is unclear how common it is to have a second concussion while not fully recovered from a first concussion, the actual mortality rate of SIS is unknown.

Retirement and Activity Restrictions Following Concussion

Sport-related concussion is prevalent at all levels of play. Increased attention from sports media and scientific and medical communities has prompted players and physicians to explore the long-term effects of concussion and ask the questions of when and how players should begin to mitigate their concussion risk. The authors evaluate their risks from the perspective of epidemiology, symptomatology, neuropsychological performance, and biomechanics. The authors propose that there is not a set number of concussions that necessitates retirement in athletes and, aside from a few absolute contraindications to return to collision sport, return to play should be an individualized process.

Neuroimaging assessment of early and late neurobiological sequelae of traumatic brain injury: implications for CTE

Traumatic brain injury (TBI) has been increasingly accepted as a major external risk factor for neurodegenerative morbidity and mortality. Recent evidence indicates that the resultant chronic neurobiological sequelae following head trauma may, at least in part, contribute to a pathologically distinct disease known as Chronic Traumatic Encephalopathy (CTE). The clinical manifestation of CTE is variable, but the symptoms of this progressive disease include impaired memory and cognition, affective disorders (i.e., impulsivity, aggression, depression, suicidality, etc.), and diminished motor control. Notably, mounting evidence suggests that the pathology contributing to CTE may be caused by repetitive exposure to subconcussive hits to the head, even in those with no history of a clinically evident head injury. Given the millions of athletes and military personnel with potential exposure to repetitive subconcussive insults and TBI, CTE represents an important public health issue. However, the incidence rates and pathological mechanisms are still largely unknown, primarily due to the fact that there is no in vivo diagnostic tool. The primary objective of this manuscript is to address this limitation and discuss potential neuroimaging modalities that may be capable of diagnosing CTE in vivo through the detection of tau and other known pathological features. Additionally, we will discuss the challenges of TBI research, outline the known pathology of CTE (with an emphasis on Tau), review current neuroimaging modalities to assess the potential routes for in vivo diagnosis, and discuss the future directions of CTE research.

Normative Versus Baseline Paradigms for Detecting Neuropsychological Impairment Following Sports-Related Concussion

Objective: Obtaining baseline neuropsychological (NP) data to assist management of sports-related concussion has been considered the standard of care. The validity of this approach has been questioned, with suggestions that post-concussion testing alone will suffice. The present study compared the sensitivity of baseline and normative paradigms in the setting of sports-related concussion.

Method: Baseline NP data were collected for 194 Australian rugby league athletes on a brief battery of paper-and-pencil NP tests. During competition, 27 athletes sustaining concussion referred from a sports physician were retested within two days of injury. Twenty-six uninjured controls were assessed at similar intervals. The baseline paradigm was assessed using a reliable change index for pre- and post-concussion scores. The normative paradigm was assessed comparing the post-concussion score to a normative mean.

Results: The baseline paradigm was consistently more sensitive to negative change following concussion than the normative paradigm when using continuous data, despite reasonable agreement. However, when data were categorised as ‘impaired’ or ‘not-impaired’, using either 68% or 90% confidence intervals, the difference between paradigms failed to reach significance. Comparison of ROC curves for both paradigms found superior overall classification for one test and the composite score using baseline comparison data.

Conclusions: Despite being a time and resource intensive process, the baseline paradigm as a repeated-measures design may be more sensitive than the between-subjects design of the normative paradigm for detecting changes following concussion. Further work is required to determine the validity of normative assessment in sports-related concussion.

A critical review of chronic traumatic encephalopathy

Chronic traumatic encephalopathy (CTE) has been described in the literature as a neurodegenerative disease with: (i) localized neuronal and glial accumulations of phosphorylated tau (p-tau) involving perivascular areas of the cerebral cortex, sulcal depths, and with a preference for neurons within superficial cortical laminae; (ii) multifocal axonal varicosities and axonal loss involving deep cortex and subcortical white matter; (iii) relative absence of beta-amyloid deposits; (iv) TDP-43 immunoreactive inclusions and neurites; and (v) broad and diverse clinical features. Some of the pathological findings reported in the literature may be encountered with age and other neurodegenerative diseases. However, the focality of the p-tau cortical findings in particular, and the regional distribution, are believed to be unique to CTE. The described clinical features in recent cases are very similar to how depression manifests in middle-aged men and with frontotemporal dementia as the disease progresses. It has not been established that the described tau pathology, especially in small amounts, can cause complex changes in behavior such as depression, substance abuse, suicidality, personality changes, or cognitive impairment. Future studies will help determine the extent to which the neuropathology is causally related to the diverse clinical features.

Cognitive changes and dementia risk after traumatic brain injury: implications for aging military personnel

Traumatic brain injury (TBI) is recognized as an important risk factor for the long-term cognitive health of military personnel, particularly in light of growing evidence that TBI increases risk for Alzheimer's disease and other dementias. In this article, we review the neurocognitive and neuropathologic changes after TBI with particular focus on the potential risk for cognitive decline across the life span in military service members. Implications for monitoring and surveillance of cognition in the aging military population are discussed. Additional studies are needed to clarify the factors that increase risk for later life cognitive decline, define the mechanistic link between these factors and dementia, and provide empirically supported interventions to mitigate the impact of TBI on cognition across the life span.

Advanced topics in neuropsychological assessment following sport-related concussion

OBJECTIVE

This study examined seven topics relating to neuropsychological assessment following sport-related concussion: (i) traditional vs. computerized tests; (ii) the value of baseline, pre-season testing; (iii) invalid baseline scores and poor effort; (iv) when to assess following injury; (v) the reliability of neuropsychological tests; (vi) reliable change methodology; and (vii) new methods for identifying cognitive impairment.

MAIN RESULTS

Baseline testing can be helpful for quantifying cognitive deficits following injury and for assessing recovery. At present, however, there is insufficient evidence to conclude that having baseline test results is clearly superior to not having baseline test results. Although invalid baseline test performance can be detected in some athletes, validity indicators cannot determine the extent to which the results were due to deliberately poor performance, confusion or misunderstanding regarding some aspect of the test, distractions in group testing environments or some combination of factors. When interpreting baseline and post-injury data, sophisticated psychometric methods (e.g. reliable change, multivariate base rates) are available to assist with more accurate identification of cognitive impairment and the serial monitoring of recovery.

CONCLUSIONS

The value of neuropsychological assessment in the management of sport-related concussion has a strong empirical foundation. Additional research is needed, however, to refine its use.

Neurological assessment and its relationship to CSF biomarkers in amateur boxers

BACKGROUND

Mild traumatic brain injury (TBI) or concussion is common in many sports. Today, neuropsychological evaluation is recommended in the monitoring of a concussion and in return-to-play considerations. To investigate the sensitivity of neuropsychological assessment, we tested amateur boxers post bout and compared with controls. Further the relationship between neuropsychological test results and brain injury biomarkers in the cerebrospinal fluid (CSF) were investigated.

METHOD

Thirty amateur boxers on high elite level with a minimum of 45 bouts and 25 non-boxing matched controls were included. Memory tests (Rey Osterrieth Complex Figure, Listening Span, Digit Span, Controlled Word Association Test, and computerized testing of episodic memory), tests of processing speed and executive functions (Trail Making, Reaction Time, and Finger Tapping) were performed and related to previously published CSF biomarker results for the axonal injury marker neurofilament light (NFL).

RESULTS

The neurological assessment showed no significant differences between boxers and controls, although elevated CSF NFL, as a sign of axonal injury, was detected in about 80% of the boxers 1-6 days post bout. The investigation of the relationship between neuropsychological evaluation and CSF NFL concentrations revealed that boxers with persisting NFL concentration elevation after at least 14 days resting time post bout, had a significantly poorer performance on Trail Making A (p = 0.041) and Simple Reaction Time (p = 0.042) compared to other boxers.

CONCLUSION

This is the first study showing traumatic axonal brain injury can be present without measureable cognitive impairment. The repetitive, subconcussive head trauma in amateur boxing causes axonal injury that can be detected with analysis of CSF NFL, but is not sufficient to produce impairment in memory tests, tests of processing speed, or executive functions. The association of prolonged CSF NFL increase in boxers with impairment of processing speed is an interesting observation, which needs to be verified in larger studies.

Modern chronic traumatic encephalopathy in retired athletes: what is the evidence?

It has been theorized that a career in contact sports may be associated with long-term neurodegenerative changes. This idea dates as far back as the 1920s, was initially reported in boxers, colloquially termed 'punch drunk,' later more formally termed dementia pugilistica (DP), and now coined chronic traumatic encephalopathy (CTE). Despite considerable ongoing interest on this topic, there is so far only limited evidence showing an association between sport-related concussion (SRC) and increased risk for late-life cognitive and neuropsychiatric impairment, with no causality or risk factors yet determined. The modern CTE description is nevertheless proposed as a unique tauopathy with characteristic pathological stages occurring in retired athletes who have experienced previous repetitive brain trauma. This review highlights the principal issues that so far preclude firm conclusions about the association of athletic head trauma and neurodegenerative diseases of any type. We consider alternative interpretations that may contribute to the clinical progressive neurological findings in some athletes and recommend carefully-controlled epidemiological work to overcome current limitations in this area of research and stimulate future research.

Invalid performance and the ImPACT in national collegiate athletic association division I football players

CONTEXT

Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a computerized cognitive test battery commonly used for concussion evaluation. An important aspect of these procedures is baseline testing, but researchers have suggested that many users do not use validity indices to ensure adequate effort during testing. No one has examined the prevalence of invalid performance for college football players.

OBJECTIVE

To examine the prevalence of invalid scores on ImPACT testing.

DESIGN

Cross-sectional study.

SETTING

National Collegiate Athletic Association Division I university.

PATIENTS OR OTHER PARTICIPANTS

A total of 159 athletes (age = 20.3 ± 1.41 years; range = 17.8-23.7 years) from a Division I collegiate football team participated.

INTERVENTION(S)

An informational intervention regarding the importance of concussion testing to promote safety was administered before testing for the most recent season.

MAIN OUTCOME MEASURE(S)

We examined preseason ImPACT testing data across a 3-year period (total assessments = 269). Based on invalid and sandbagging indices denoted by the ImPACT manual, protocols were examined to indicate how many invalid indices each athlete had.

RESULTS

A total of 27.9% (n = 75) of assessments were suggestive of invalid scores, with 4.1% (n = 11) suggesting invalid responding only, 17.5% (n = 47) indicating "sandbagging" only, and 6.3% (n = 17) showing both invalid and sandbagging responding. The informational intervention did not reduce the prevalence of invalid responding.

CONCLUSIONS

These findings highlight the need for further information about the ImPACT validity indices and whether they truly reflect poor effort. Future work is needed to identify practices to reliably target and reduce invalid responding.

Prevalence and characterization of mild cognitive impairment in retired national football league players

It has been hypothesized that exposure to repetitive head trauma from contact sports over a long-playing career may eventuate in an increased risk of late-life cognitive impairment. There are currently two competing hypotheses about the possible mechanism underlying such impairment. One is the presence of a unique neurodegenerative disorder known as ‘‘chronic traumatic encephalopathy’’ (CTE). The other is diminished cerebral reserve leading to the earlier clinical expression of age-related neurodegenerative diseases such as mild cognitive impairment (MCI) and Alzheimer’s disease(AD). The present study examined informant AD8 inventory data in a sample of 513 retired National Football League(NFL) players. These data were indicative of possible cognitive impairment in 35.1% of this relatively young sample. A comparison of neurocognitive profiles in a subsample of this group to a clinical sample of patients with a diagnosis of MCI due to AD revealed a highly similar profile of impairments. Overall, the data suggest that there may be an increased prevalence of late-life cognitive impairment in retired NFL players, which may reflect diminished cerebral reserve. The findings are considered preliminary, but emphasize the need for larger, controlled studies on this issue.

Post-concussion symptom reporting after multiple mild traumatic brain injuries

The relationship between previous mild traumatic brain injury/injuries (MTBI) and recovery from a subsequent MTBI may be complex. The present study investigated three factors hypothesized to influence this relation: (1) the number of prior MTBIs, (2) the interval between MTBIs, and (3) the certainty level of previous MTBIs. The study design was retrospective cross-sectional. Participants (N=105) were evaluated at a concussion clinic on average 1 month after sustaining an MTBI, defined by World Health Organization diagnostic criteria. Approximately half the sample had at least one previous MTBI. Subgroups with 0, 1, or 2+ previous MTBIs did not differ in levels of current post-concussion symptom reporting on the British Columbia Post-Concussion Symptom Inventory. Time since the most recent previous MTBI was significantly associated with current post-concussion symptom reporting. This relation was best characterized as logarithmic; i.e., the impact of previous MTBI(s) lessens exponentially as time elapses to a subsequent MTBI. Defining previous MTBIs with a higher certainty level (i.e., probable versus possible) was not consistently associated with greater post-concussion symptom reporting. In conclusion, participants with multiple MTBIs did not report more post-concussion symptoms than those with no history of MTBI. Previous MTBI(s), however, were associated with increased symptom reporting from a subsequent MTBI to the extent they occurred closer in time. Having one or two previous remote MTBIs was not associated with worse outcome from subsequent MTBI in this sample.

Evidence for added value of baseline testing in computer-based cognitive assessment

CONTEXT

Large-scale baseline cognitive assessment for individuals at risk for concussion is a common part of the protocol for concussion-surveillance programs, particularly in sports. Baseline cognitive testing is also being conducted in US military service members before deployment. Recently, the incremental validity of large-scale baseline cognitive assessment has been questioned.

OBJECTIVE

To examine the added value of baseline cognitive testing in computer-based neuropsychological assessment by comparing 2 methods of classifying atypical performance in a presumed healthy sample.

DESIGN

Cross-sectional study.

SETTING

Military base.

PATIENTS OR OTHER PARTICIPANTS

Military service members who took the Automated Neuropsychological Assessment Matrix (ANAM) before and after deployment (n = 8002).

MAIN OUTCOME MEASURE(S)

Rates of atypical performance in this healthy, active-duty sample were determined first by comparing postdeployment scores with a military normative database and then with each individual's personal baseline performance using a reliable change index.

RESULTS

Overall rates of atypical performance were comparable across these 2 methods. However, these methods were highly discordant in terms of which individuals were classified as atypical. When norm-referenced methods were used, 2.6% of individuals classified as normal actually demonstrated declines from baseline. Further, 65.7% of individuals classified as atypical using norm-referenced scores showed no change from baseline (ie, potential false-positive findings).

CONCLUSIONS

Knowing an individual's baseline performance is important for minimizing potential false-positive errors and reducing the risks and stresses of misdiagnosis.

Concept analysis of concussion

PURPOSE

Concussion has been estimated to occur in 1.6-3.8 million adolescent athletes in the United States each year. However, because of conceptual ambiguity regarding its definition, the true incidence is estimated to be significantly higher. This article seeks to identify and support a single definition for the term concussion.

CONCLUSIONS

Defining attributes, antecedents, and consequences of concussion allow for a better understanding of this concept. Sample cases from pediatric clinical practice further clarify the concept as it applies to pediatric nursing.

PRACTICE IMPLICATIONS

A clear definition has the potential to increase knowledge and recognition of concussion injury, leading to strategies that would decrease the risk of long-term effects and devastating outcomes.

Chronic traumatic encephalopathy in sport: a systematic review

OBJECTIVE

To provide a critical review of chronic traumatic encephalopathy (CTE) by considering the range of clinical presentations, neuropathology and the strength of evidence for CTE as a distinct syndrome.

DATA SOURCES

Seven electronic databases were searched using a combination of MeSH terms and key words to identify relevant articles.

REVIEW METHODS

Specific inclusion and exclusion criteria were used to select studies for review. Data extracted where present included study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, investigation results and neuropathology results.

RESULTS

The data from 158 published case studies were reviewed. Critical differences between the older descriptions of CTE (the 'classic' syndrome) and the recent descriptions (the 'modern' syndrome) exist in the age of onset, natural history, clinical features, pathological findings and diagnostic criteria, which suggests that modern CTE is a different syndrome. The methodology of the current studies does not allow determination of aetiology or risk factors.

CONCLUSIONS

The clinicopathological differences between the 'classic' CTE syndrome and the 'modern' syndrome suggest that the new syndrome needs a different nomenclature. Further research is required to clearly define the clinical phenotype of the modern CTE syndrome and establish the underlying aetiology. Future research needs to address these issues through large-scale, prospective clinicopathological studies.

The utility of post-concussion neuropsychological data in identifying cognitive change following sports-related MTBI in the absence of baseline data

Neuropsychological tests have become commonplace in the assessment of sports-related concussion. Typically, post-injury test data are compared to pre-injury "baselines." Baseline testing can be expensive and logistically challenging, yet the usefulness of neuropsychological baseline testing has not been tested empirically. This paper examines the extent to which baseline testing is useful for detecting neurocognitive deficits following sports concussion in a college-age population. A total of 223 collegiate athletes from multiple sports who sustained concussions and had both baseline and post-injury testing using Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) were included in the study. Reliable change (RC) in scores was determined by two approaches, the Jacobson and Truax (JT) and the Gulliksen-Lord-Novick (GLN) methods. The 90% confidence interval was used for both. Classification using these methods was compared to standard normative methods that compared post-concussion performance to baseline population means. Agreement between reliable change and normative methods was examined using Cohen's Kappa scores to determine whether post-injury scores alone could identify reliable cognitive decline. Mean time from concussion to post-injury testing was 3.40 days. The percentage of athletes who declined when using the JT method was similar to the percentage that would be expected to decline due to chance alone. Although the GLN and JT methods demonstrated moderate to substantial agreement, the GLN method consistently identified more cognitively compromised athletes than the JT method. Post-injury scores alone identified a significant majority of athletes with a reliable decline on ImPACT. Although preliminary and in need of replication across age groups and instruments, these findings suggest that the majority of collegiate athletes who experience clinically meaningful post-concussion cognitive decline can be identified without baseline data.

Cerebral Concussion in Sport: An Overview

Sports-related concussions are ubiquitous in contact and collision sports at all levels of play and across a broad age range. Once thought to be a nuisance injury, it is now recognized that these brain injuries may lead to chronic neurocognitive impairment if not managed properly. This paper provides a broad overview of the research and clinical data that have emerged in this rapidly growing area. Included in the review are discussions of injury definition, pathophysiology, signs and symptoms, epidemiology, potential long-term consequences, assessment, and psychological factors. Issues of prevention and education are discussed in light of further increasing awareness of this injury.

The relationship between psychological distress and baseline sports-related concussion testing

OBJECTIVE

This study examined the effect of psychological distress on neurocognitive performance measured during baseline concussion testing.

DESIGN

Archival data were utilized to examine correlations between personality testing and computerized baseline concussion testing. Significantly correlated personality measures were entered into linear regression analyses, predicting baseline concussion testing performance. Suicidal ideation was examined categorically.

SETTING

Athletes underwent testing and screening at a university athletic training facility.

PARTICIPANTS

Participants included 47 collegiate football players 17 to 19 years old, the majority of whom were in their first year of college.

INTERVENTIONS

Participants were administered the Concussion Resolution Index (CRI), an internet-based neurocognitive test designed to monitor and manage both at-risk and concussed athletes. Participants took the Personality Assessment Inventory (PAI), a self-administered inventory designed to measure clinical syndromes, treatment considerations, and interpersonal style.

MAIN OUTCOME MEASURES

Scales and subscales from the PAI were utilized to determine the influence psychological distress had on the CRI indices: simple reaction time, complex reaction time, and processing speed.

RESULTS

Analyses revealed several significant correlations among aspects of somatic concern, depression, anxiety, substance abuse, and suicidal ideation and CRI performance, each with at least a moderate effect. When entered into a linear regression, the block of combined psychological symptoms accounted for a significant amount of baseline CRI performance, with moderate to large effects (r = 0.23-0.30). When examined categorically, participants with suicidal ideation showed significantly slower simple reaction time and complex reaction time, with a similar trend on processing speed.

CONCLUSIONS

Given the possibility of obscured concussion deficits after injury, implications for premature return to play, and the need to target psychological distress outright, these findings heighten the clinical importance of screening for psychological distress during baseline and post-injury concussion evaluations.