A Meta-Analysis of Neuropsychological Outcome After Mild Traumatic Brain Injury: Re-analyses and Reconsiderations of Binder et al. (1997), Frencham et al. (2005), and Pertab et al. (2009)

Neuroimaging and Psychometric Assessment of Mild Cognitive Impairment After Traumatic Brain Injury

Traumatic brain injury (TBI) can be serious partly due to the challenges of assessing and treating its neurocognitive and affective sequelae. The effects of a single TBI may persist for years and can limit patients’ activities due to somatic complaints (headaches, vertigo, sleep disturbances, nausea, light or sound sensitivity), affective sequelae (post-traumatic depressive symptoms, anxiety, irritability, emotional instability) and mild cognitive impairment (MCI, including social cognition disturbances, attention deficits, information processing speed decreases, memory degradation and executive dysfunction). Despite a growing amount of research, study comparison and knowledge synthesis in this field are problematic due to TBI heterogeneity and factors like injury mechanism, age at or time since injury. The relative lack of standardization in neuropsychological assessment strategies for quantifying sequelae adds to these challenges, and the proper administration of neuropsychological testing relative to the relationship between TBI, MCI and neuroimaging has not been reviewed satisfactorily. Social cognition impairments after TBI (e.g., disturbed emotion recognition, theory of mind impairment, altered self-awareness) and their neuroimaging correlates have not been explored thoroughly. This review consolidates recent findings on the cognitive and affective consequences of TBI in relation to neuropsychological testing strategies, to neurobiological and neuroimaging correlates, and to patient age at and assessment time after injury. All cognitive domains recognized by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) are reviewed, including social cognition, complex attention, learning and memory, executive function, language and perceptual-motor function. Affect and effort are additionally discussed owing to their relationships to cognition and to their potentially confounding effects. Our findings highlight non-negligible cognitive and affective impairments following TBI, their gravity often increasing with injury severity. Future research should study (A) language, executive and perceptual-motor function (whose evolution post-TBI remains under-explored), (B) the effects of age at and time since injury, and (C) cognitive impairment severity as a function of injury severity. Such efforts should aim to develop and standardize batteries for cognitive subdomains—rather than only domains—with high ecological validity. Additionally, they should utilize multivariate techniques like factor analysis and related methods to clarify which cognitive subdomains or components are indeed measured by standardized tests.

Persistent post-concussive symptoms: A model of predisposing, precipitating, and perpetuating factors

While the majority of individuals make full recovery within a short period following mild traumatic brain injury (mTBI), some continue to experience a more chronic course of symptoms termed persistent post-concussive symptoms (PPCS). Previous models and conceptualizations of PPCS have typically not differentiated the time at which factors present across the injury timeline spectrum or have considered a limited array of contributory factors. In the current review, PPCS are examined within the predisposing, precipitating, and perpetuating (PPP) model, which has been applied to explain other syndromes resulting in a clear framework to explain, disseminate, and further research the specified condition. Previous PPCS models are reviewed and integrated into this comprehensive model, as well. To do so, a literature review was completed which included previous PPP models applied to other conditions, other PPCS models, and more recent findings of factors related to PPCS. This new iteration and application of the PPP model more clearly, completely, and validly identifies contributing factors to PPCS. Future prevention, early identification, clearer questions for future research, and treatment of PPCS is possible with clarity provided by this model.

Normal variability within a collegiate athlete sample: A rationale for comprehensive baseline testing

OBJECTIVE

Sport-related concussions continue to garner attention as research emerges about the effects of these injuries. Many have advocated for cognitive baselines; however, there is no uniform practice of neuropsychological baseline testing at the collegiate level leading to variance in administration and interpretation. Continuing clarification on best practices is essential for the field, especially considering previous research highlighting normal variability on cognitive tests in other populations, but also the need for separate normative sources for those with attention and learning problems. This study aimed to evaluate the range of normal variability in a diverse sample of collegiate athletes administered a traditional neuropsychological baseline.

METHOD

Neuropsychological baseline measures were collected on 236 Division 1 University student athletes over 4 years. Frequency of scores that fell at 1, 1.5, and 2 or greater standard deviations were reviewed. Student athletes were further evaluated for likelihood of factors which could impact results (i.e. Attention-Deficit/Hyperactivity Disorder [ADHD], Specific Learning Disorder [SLD], and psychiatric distress).

RESULTS

The results demonstrated high rates of variability in most test scores for the collective sample. Student athletes at risk for ADHD, SLD, and/or psychiatric distress appeared to demonstrate a higher degree of variability relative to individuals with minimal risk.

CONCLUSION

Baseline evaluation data revealed the presence of normal variability in a student athlete population. Left unrecognized, this can lead to errors in clinical recommendations given the nature of concussion. Certain individuals have risk factors which may increase the range of variability, and this should be explored further in future research.

The Effect of Traumatic Brain Injury (TBI) on Cognitive Performance in a Sample of Active Duty U.S. Military Service Members

Introduction

Traumatic brain injury (TBI) is considered a signature injury from the fighting in Iraq and Afghanistan. Since the year 2000, over 370,000 U.S. active duty service members have been diagnosed with TBI. Although prior research has shown that even mild forms of TBI are associated with impaired cognitive performance, it is not clear which facets of cognition (computation, memory, reasoning, etc.) are impacted by injury.

Method

In the present study, we compared active duty military volunteers (n = 88) with and without TBI on six measures of cognition using the Automated Neuropsychological Assessment Metric software.

Results

Healthy volunteers exhibited significantly faster response times on the matching-to-sample, mathematical processing, and second round of simple reaction time tasks and had higher throughput scores on the mathematical processing and the second round of the simple reaction time tasks (P < 0.05).

Conclusion

In this population, cognitive impairments associated with TBI influenced performance requiring working memory and basic neural processing (speed/efficiency).

A Novel Intervention Platform for Service Members With Subjective Cognitive Complaints: Implementation, Patient Participation, and Satisfaction

Introduction

Program overview of a novel cognitive training platform at Walter Reed National Military Medical Center (WRNMMC) for service members with subjective cognitive complaints: analysis of patient participation, satisfaction with the program, and perceived areas of improvement.

Materials and Method

Retrospective review of 1,030 participants from November 2008 through May 2017. Data were obtained within an approved protocol (WRNMMC-EDO-2017-0004/# 876230).

Results

The program has shown growth in numbers of referrals, types of patient populations served, and patient visits. Patients report satisfaction with the program and endorse improvements in cognitive functions.

Conclusions

This program model may benefit other military facilities looking to provide and assess novel therapeutic approaches.

History of Sport-Related Concussion and Long-Term Clinical Cognitive Health Outcomes in Retired Athletes: A Systematic Review

BACKGROUND

Sport-related concussions (SRCs) are known to have short-term effects on cognitive processes, which can result in diverse clinical presentations. The long-term effects of SRC and repeated exposure to head impacts that do not result in SRC on specific cognitive health outcomes remain unclear.

OBJECTIVES

To synthesize and appraise the evidence base regarding cognitive health in living retired athletes with a history of head-impact exposure or SRC.

DATA SOURCES

A systematic search of the EMBASE, PsycINFO, MEDLINE/PubMed, CINAHL, Cochrane Central Register of Controlled Trials, and Web of Science databases was conducted from inception to April 2018 using common key words and medical subject headings related to 3 components: (1) the participant (eg, retired athlete), (2) the primary outcome measure (eg, cognitive test used), and (3) the secondary outcome measure (eg, history of sport concussion).

STUDY SELECTION

Cross-sectional studies of living retired male or female athletes in which at least 1 cognitive test was used as an outcome measure were included. Two reviewers independently screened studies.

DATA EXTRACTION

Data extraction was performed using Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Methodologic quality was assessed independently by 2 reviewers using the Downs and Black tool.

DATA SYNTHESIS

The search yielded 46 cross-sectional observational studies that were included in a qualitative synthesis. Most included studies (80%, n = 37) were published in the 5 years before our review. A large proportion of these studies (n = 20) included retired American National Football League players. The other research investigated professional, university, high school, and amateur retired athletes participating in sports such as American and Australian football, boxing, field and ice hockey, rugby, and soccer. The total sample consisted of 13 975 participants: 7387 collision-sport athletes, 662 contact-sport athletes, 3346 noncontact-sport athletes, and 2580 participants classified as controls. Compared with control participants or normative data, retired athletes displayed worse performance in 17 of 31 studies (55%) of memory, 6 of 11 studies (55%) of executive function, and 4 of 6 studies (67%) of psychomotor function and increased subjective concerns about cognitive function in 11 of 14 studies (79%). The authors of 13 of 46 investigations (28%) reported a frequency-response relationship, with poorer cognitive outcomes in athletes who had greater levels of exposure to head impacts or concussions. However, these results must be interpreted in light of the lack of methodologic rigor and moderate quality assessment of the included studies.

CONCLUSIONS

Evidence of poorer cognitive health among retired athletes with a history of concussion and head-impact exposure is evolving. Our results suggest that a history of SRC may more greatly affect the cognitive domains of memory, executive function, and psychomotor function. Retired athletes appeared to have increased self-reported cognitive difficulties, but the paucity of high-quality, prospective studies limited the conclusions that could be drawn regarding a cause-and-effect relationship between concussion and long-term health outcomes. Future researchers should consider a range of cognitive health outcomes, as well as premorbid ability, in diverse samples of athletes with or without a history of concussion or head-impact exposure to delineate the long-term effects of sport participation on cognitive functioning.

Language Comprehension After Mild Traumatic Brain Injury: The Role of Speed

Purpose The aim of this study was to characterize language comprehension in mild traumatic brain injury (mTBI) by testing a speed-based hypothesis. We hypothesized that adults with mTBI would perform worse than a group of adults with orthopedic injuries (OIs) on an experimental language comprehension task. Method The study employed a prospective experimental design. Participants were 19 adults with mTBI and 19 adults with OI ages 18-55 years. Participants completed the Whatdunit task, a sentence agent selection task in speeded and unspeeded conditions. Results In the unspeeded condition, the mTBI group performed with a marginally significant higher accuracy than the OI group. In the speeded condition, the mTBI group performed with lower accuracy than the OI group; however, this difference did not reach statistical significance. There was a marginally significant interaction of Sentence Type × Group for reaction time in the speeded condition. Conclusions While our task might have been sensitive to cognitive processing abilities in both groups (as evidenced by the main effects of condition and sentence type), the task was not specific enough to capture mTBI-related deficits. The similarities in performance between both groups have clinical implications for the treatment of not just brain-related trauma but also trauma in general.

Preinjury Psychological Factors and Case Formulation in Mild Traumatic Brain Injury Rehabilitation: A Case Report

Mild traumatic brain injury (TBI) accounts for the majority of TBIs. Most cases recover within 3 months and usual medical advice covers physical and cognitive rest, activity and fatigue management, and education. However, in some cases, symptoms can persist and there may be ongoing postconcussion difficulties. It is well established that pre- and postinjury psychological factors can contribute to cases of persistent postconcussion symptoms. However, there are few illustrative case examples in the published literature on mild TBI. This case example demonstrates the pivotal role that preinjury psychological factors can play in recovery from mild TBI, using an example of a 35-year-old woman with persistent mild TBI symptoms who had a limited response to previous brief treatment through a Concussion Clinic. Through the process of assessment and development of a psychological case formulation, preinjury psychological factors that had been barriers to recovery and prior rehabilitation efforts were identified. Rehabilitation counselors are equipped to (1) identify and address such barriers, (2) communicate this information to other rehabilitation professionals in the treatment team to facilitate a shared understanding of how factors might affect the client’s functioning and (3) contribute to team case formulation.

Randomised controlled clinical trial of a structured cognitive rehabilitation in patients with attention deficit following mild traumatic brain injury: study protocol

OBJECTIVES

To measure the clinical, structural and functional changes of an individualised structured cognitive rehabilitation in mild traumatic brain injury (mTBI) population.

SETTING

A single centre study, Malaysia.

PARTICIPANTS

Adults aged between 18 and 60 years with mTBI as a result of road traffic accident, with no previous history of head trauma, minimum of 9 years education and abnormal cognition at 3 months will be included. The exclusion criteria include pre-existing chronic illness or neurological/psychiatric condition, long-term medication that affects cognitive/psychological status, clinical evidence of substance intoxication at the time of injury and major polytrauma. Based on multiple estimated calculations, the minimum intended sample size is 50 participants (Cohen's d effect size=0.35; alpha level of 0.05; 85% power to detect statistical significance; 40% attrition rate).

INTERVENTIONS

Intervention group will receive individualised structured cognitive rehabilitation. Control group will receive the best patient-centred care for attention disorders. Therapy frequency for both groups will be 1 hour per week for 12 weeks.

OUTCOME MEASURES

Primary: Neuropsychological Assessment Battery-Screening Module (S-NAB) scores. Secondary: Diffusion Tensor Imaging (DTI) parameters and Goal Attainment Scaling score (GAS).

RESULTS

Results will include descriptive statistics of population demographics, CogniPlus cognitive program and metacognitive strategies. The effect of intervention will be the effect size of S-NAB scores and mean GAS T scores. DTI parameters will be compared between groups via repeated measure analysis. Correlation analysis of outcome measures will be calculated using Pearson's correlation coefficient.

CONCLUSION

This is a complex clinical intervention with multiple outcome measures to provide a comprehensive evidence-based treatment model.

ETHICS AND DISSEMINATION

The study protocol was approved by the Medical Research Ethics Committee UMMC (MREC ID NO: 2016928-4293). The findings of the trial will be disseminated through peer-reviewed journals and scientific conferences.

TRIAL REGISTRATION NUMBER

NCT03237676.

Results of scoping review do not support mild traumatic brain injury being associated with a high incidence of chronic cognitive impairment: Commentary on McInnes et al. 2017

A recently published review of 45 studies concluded that approximately half of individuals who sustain a single mild traumatic brain injury (MTBI) experience long-term cognitive impairment (McInnes et al. Mild Traumatic Brain Injury (mTBI) and chronic cognitive impairment: A scoping review. PLoS ONE 2017;12:e0174847). Stratified by age, they reported that 50% of children and 58% of adults showed some form of cognitive impairment. We contend that the McInnes et al. review used a definition of “cognitive impairment” that was idiosyncratic, not applicable to individual patients or subjects, inconsistent with how cognitive impairment is defined in clinical practice and research, and resulted in a large number of false positive cases of cognitive impairment. For example, if a study reported a statistically significant difference on a single cognitive test, the authors concluded that every subject with a MTBI in that study was cognitively impaired–an approach that cannot be justified statistically or psychometrically. The authors concluded that impairment was present in various cognitive domains, such as attention, memory, and executive functioning, but they did not analyze or report the results from any of these specific cognitive domains. Moreover, their analyses and conclusions regarding many published studies contradicted the interpretations provided by the original authors of those studies. We re-reviewed all 45 studies and extracted the main conclusions from each. We conclude that a single MTBI is not associated with a high incidence of chronic cognitive impairment.

Recovery After Mild Traumatic Brain Injury in Patients Presenting to US Level I Trauma Centers: A Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Study

Importance

Most traumatic brain injuries (TBIs) are classified as mild (mTBI) based on admission Glasgow Coma Scale (GCS) scores of 13 to 15. The prevalence of persistent functional limitations for these patients is unclear.

Objectives

To characterize the natural history of recovery of daily function following mTBI vs peripheral orthopedic traumatic injury in the first 12 months postinjury using data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, and, using clinical computed tomographic (CT) scans, examine whether the presence (CT+) or absence (CT-) of acute intracranial findings in the mTBI group was associated with outcomes.

Design, Setting, and Participants

TRACK-TBI, a cohort study of patients with mTBI presenting to US level I trauma centers, enrolled patients from February 26, 2014, to August 8, 2018, and followed up for 12 months. A total of 1453 patients at 11 level I trauma center emergency departments or inpatient units met inclusion criteria (ie, mTBI [n = 1154] or peripheral orthopedic traumatic injury [n = 299]) and were enrolled within 24 hours of injury; mTBI participants had admission GCS scores of 13 to 15 and clinical head CT scans. Patients with peripheral orthopedic trauma injury served as the control (OTC) group.

Exposures

Participants with mTBI or OTC.

Main Outcomes and Measures

The Glasgow Outcome Scale Extended (GOSE) scale score, reflecting injury-related functional limitations across broad life domains at 2 weeks and 3, 6, and 12 months postinjury was the primary outcome. The possible score range of the GOSE score is 1 (dead) to 8 (upper good recovery), with a score less than 8 indicating some degree of functional impairment.

Results

Of the 1453 participants, 953 (65.6%) were men; mean (SD) age was 40.9 (17.1) years in the mTBI group and 40.9 (15.4) years in the OTC group. Most participants (mTBI, 87%; OTC, 93%) reported functional limitations (GOSE <8) at 2 weeks postinjury. At 12 months, the percentage of mTBI participants reporting functional limitations was 53% (95% CI, 49%-56%) vs 38% (95% CI, 30%-45%) for OTCs. A higher percentage of CT+ patients reported impairment (61%) compared with the mTBI CT- group (49%; relative risk [RR], 1.24; 95% CI, 1.08-1.43) and a higher percentage in the mTBI CT-group compared with the OTC group (RR, 1.28; 95% CI, 1.02-1.60).

Conclusions and Relevance

Most patients with mTBI presenting to US level I trauma centers report persistent, injury-related life difficulties at 1 year postinjury, suggesting the need for more systematic follow-up of patients with mTBI to provide treatments and reduce the risk of chronic problems after mTBI.

Validity and reliability of the Neuropsychological Assessment Battery - Screening Module (S-NAB) in a subset of Malaysian population with mild traumatic brain injury (mTBI)

This study assessed the validity (construct validity) and reliability (internal consistency) of the Neuropsychological Assessment Battery Screening Module (S-NAB) in detecting mild cognitive deficit/alteration in multicultural, multilingual, and multiethnic mild traumatic brain injury (mTBI) population of Malaysia. S-NAB and Montreal Cognitive Assessment (MoCA) data from 114 patients with mTBI (93 males; 21 females) aged 18 to 60 years old were obtained at University Malaya Medical Center, Malaysia. The mean age was 28.17 ± 8.57 years and mean education years was 12.40 ± 2.01. Convergent validity was assessed between S-NAB domain scores and MoCA total scores by using Pearson's correlation and internal consistency was assessed using Cronbach's alpha. Acceptable internal consistency (α ≥ .70) was found for Attention, Language, and Memory domains but weak internal consistencies (α < .50) were found for Spatial and Executive Function domains. There were positive but weak correlations between S-NAB and MoCA. These findings provide some support for the application of S-NAB in assessing mild cognitive deficits of mTBI population in a Malaysian setting.

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.

Performance on the repeatable battery for the assessment of neuropsychological status in college students with mild traumatic brain injury

College students recovering from mild traumatic brain injury (MTBI) often experience a constellation of symptoms including cognitive and emotional difficulties. While these symptoms may interfere with academic performance, few students seek supportive services. Assessment of MTBI symptoms may be important to help identify students with symptoms that may interfere with academic performance and assist them in obtaining appropriate treatment and support services. The purpose of this study was to evaluate cognitive performance of college students with a history of MTBI on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) as well as symptoms of anxiety and depression. A total of seventy college students participated in this study. Participants were divided into two groups based on self-reported history of MTBI. Participants with a history of MTBI (n = 22) performed significantly higher (p < .05) on the RBANS Delayed Memory Index and endorsed significantly fewer (p < .05) trait anxiety symptoms on the State-Trait Anxiety Inventory (STAI) than students without a history of head injury (n = 48). Students with a history of MTBI displayed few impairments on the RBANS and are more likely to endorse fewer symptoms of trait anxiety (but not state anxiety or depression) than peers without a history of head injury.

Neuroimaging and Neuropsychological Studies in Sports-Related Concussions in Adolescents: Current State and Future Directions

Sports-related concussion, is a serious neurological concern that many adolescent athletes will face during their athletic careers. In some instances, the effects of sports-related head injury are long-lasting. Due to their still-developing brains, adolescents appear to be more vulnerable to long-term repercussions of these injuries. As all sports-related concussions are mild traumatic brain injuries (mTBI), this review we will examine the pathophysiology of mTBI, its acute effects and long-term risks from sustaining injury, and current and needed advancements in the areas of neuropsychological testing, accelerometer telemetry, and neuroimaging. Current methods do not adequately measure the extent of an injury that an athlete may sustain, potentially putting these athletes at a much greater risk for long-term effects. To better understand mTBI, neuropsychological testing best practices need to be developed, standardized, and implemented based on sound scientific evidence in order to be propagated as clinical guidelines. Wearable accelerometers can be used to assess thresholds for mTBI and cumulative effects of concussive and subconcussive injuries. Novel neuroimaging methods that can detect anatomical abnormalities and functional deficits with more specificity and sensitivity should be developed. Young athletes are particularly a vulnerable population warranting immediate and significant research aimed at protecting them against sports related injury and mitigating their long-term deficits.

Montreal Cognitive Assessment as a screening tool: Influence of performance and symptom validity

BACKGROUND

We evaluated Montreal Cognitive Assessment (MoCA) performance in a veteran traumatic brain injury (TBI) population, considering performance validity test (PVT) and symptom validity test (SVT) data, and explored associations of MoCA performance with neuropsychological test performance and self-reported distress.

METHODS

Of 198 consecutively referred veterans to a Veterans Administration TBI/Polytrauma Clinic, 117 were included in the final sample. The MoCA was administered as part of the evaluation. Commonly used measures of neuropsychological functioning and performance and symptom validity were also administered to aid in diagnosis.

RESULTS

Successively worse MoCA performances were associated with a greater number of PVT failures (ps < 0.05). Failure of both the SVT and at least 1 PVT yielded the lowest MoCA scores. Self-reported distress (both posttraumatic stress disorder symptoms and neurobehavioral cognitive symptoms) was also related to MoCA performance.

CONCLUSIONS

Performance on the MoCA is influenced by task engagement and symptom validity. Causal inferences about neurologic and neurocognitive impairment, particularly in the context of mild TBI, wherein the natural course of recovery is well known, should therefore be made cautiously when such inferences are based heavily on MoCA scores. Neuropsychologists are well versed in the assessment of performance and symptom validity and thus may be well suited to explore the influences of abnormal performances on cognitive screening.

Cognitive Impairment Following Acute Mild Traumatic Brain Injury

Patients with mild traumatic brain injury (mTBI) may present cognitive deficits within the first 24 h after trauma, herein called "acute phase," which in turn may lead to long-term functional impairment and decrease in quality of life. Few studies investigated cognition in mTBI patients during the acute phase. The objectives of this study were to investigate the cognitive profile of patients with mTBI during the acute phase, compared to controls and normative data, and whether loss of consciousness (LOC), previous TBI and level of education influence cognition at this stage. Fifty-three patients with mTBI (aged 19-64 years) and 28 healthy controls participated in the study. All patients were evaluated at bedside within 24 h post-injury. Demographic and clinical data were registered. Cognitive function was assessed with the Mini-mental state examination (MMSE), the Frontal Assessment Battery (FAB), Digit Span (working memory), and the Visual Memory Test/Brief Cognitive Battery (for episodic memory). The clinical sample was composed mainly by men (58.5%). The mean age was 39 years-old and 64.3% of the patients had more than 8 years of education. The most common causes of mTBI were fall from own height (28.3%), aggression (24.5%), and fall from variable heights (24.5%). Compared to controls, mTBI patients exhibited significantly worse performance on MMSE, FAB, naming, incidental memory, immediate memory, learning, and delayed recall. Compared to normative data, 26.4% of patients had reduced global cognition as measured by the MMSE. Episodic memory impairment (13.2%) was more frequent than executive dysfunction (9.4%). No significant differences were found in cognitive performance when comparing patients with or without LOC or those with or without history of previous TBI. Patients with lower educational level had higher rates of cognitive impairment (VMT naming-28.6 vs. 4.2%; VMT immediate memory-32 vs. 4.2%; VMT learning-39.3 vs. 4.2%, all p < 0.05). In sum, we found significant cognitive impairment in the acute phase of mTBI, which was not associated with LOC or history of TBI, but appeared more frequently in patients with lower educational level.

Clinical relevance of microhemorrhagic lesions in subacute mild traumatic brain injury

Magnetic resonance imaging (MRI) is often performed in patients with persistent complaints after mild traumatic brain injury (mTBI). However, the clinical relevance of detected microhemorrhagic lesions is still unclear. In the current study, 54 patients with uncomplicated mTBI and 20 matched healthy controls were included. Post-traumatic complaints were measured at two weeks post-injury. Susceptibility weighted imaging and T2*-gradient echo imaging (at 3 Tesla) were performed at four weeks post-injury. Microhemorrhagic lesions (1–10 mm) were subdivided based on depth (superficial or deep) and anatomical location (frontal, temporoparietal and other regions). Twenty-eight per cent of patients with mTBI had ≥1 lesions compared to 0 % of the healthy controls. Lesions in patients with mTBI were predominantly located within the superficial frontal areas. Number, depth and anatomical location of lesions did not differ between patients with and without post-traumatic complaints. Within the group of patients with complaints, number of complaints was not correlated with number of lesions. In summary, microhemorrhages were found in one out of four patients with uncomplicated mTBI during follow-up at four weeks post-injury, but they were not related to early complaints.

Associations between neuropsychiatric and health status outcomes in individuals with probable mTBI

Mild traumatic brain injury (mTBI) is a common occurrence, and may impact distal outcomes in a subgroup of individuals. Improved characterization of health outcomes and identification of factors associated with poor outcomes is needed to better understand the impact of mTBI, particularly in those with co-occurring posttraumatic stress disorder (PTSD). Participants in a data repository of the Injury and Traumatic Stress (INTRuST) Clinical Consortium (n = 625) completed functional disability [FD] and health-related quality of life [HRQOL] questionnaires, and a subset completed a neuropsychological assessment. FD and HRQOL were compared among participants with probable mTBI (mTBI), probable mTBI with PTSD (mTBI/PTSD), and health comparison participants (HC). Associations between symptoms, neuropsychological performance, and health outcomes were examined in those with probable mTBI with and without PTSD (n = 316). Individuals in the mTBI/PTSD group endorsed poorer health outcomes than those in the mTBI group, who endorsed poorer outcomes than those in the HC group. Individuals in either mTBI group performed worse than those in the HC on verbal learning and memory and psychomotor speed. Health outcomes were correlated with mental health and postconcussive symptoms, as well as neuropsychological variables. mTBI may adversely impact self-reported health, with the greatest effect observed in individuals with co-occurring mTBI/PTSD.

Wait, There’s a Baby in this Bath Water! Update on Quantitative and Qualitative Cut-Offs for Rey 15-Item Recall and Recognition

Objective

Evaluate the effectiveness of Rey 15-item plus recognition data in a large neuropsychological sample.

Method

Rey 15-item plus recognition scores were compared in credible (n = 138) and noncredible (n = 353) neuropsychology referrals.

Results

Noncredible patients scored significantly worse than credible patients on all Rey 15-item plus recognition scores. When cut-offs were selected to maintain at least 89.9% specificity, cut-offs could be made more stringent, with the highest sensitivity found for recognition correct (cut-off ≤11; 62.6% sensitivity) and the combination score (recall + recognition – false positives; cut-off ≤22; 60.6% sensitivity), followed by recall correct (cut-off ≤11; 49.3% sensitivity), and recognition false positive errors (≥3; 17.9% sensitivity). A cut-off of ≥4 applied to a summed qualitative error score for the recall trial resulted in 19.4% sensitivity. Approximately 10% of credible subjects failed either recall correct or recognition correct, whereas two-thirds of noncredible patients (67.7%) showed this pattern. Thirteen percent of credible patients failed either recall correct, recognition correct, or the recall qualitative error score, whereas nearly 70% of noncredible patients failed at least one of the three. Some individual qualitative recognition errors had low false positive rates (&lt;2%) indicating that their presence was virtually pathognomonic for noncredible performance. Older age (&gt;50) and IQ &lt; 80 were associated with increased false positive rates in credible patients.

Conclusions

Data on a larger sample than that available in the 2002 validation study show that Rey 15-item plus recognition cut-offs can be made more stringent, and thereby detect up to 70% of noncredible test takers, but the test should be used cautiously in older individuals and in individuals with lowered IQ.

Clinical Findings in a Multicenter MRI Study of Mild TBI

Background: Uncertainty continues to surround mild traumatic brain injury (mTBI) diagnosis, symptoms, prognosis, and outcome due in part to a lack of objective biomarkers of injury and recovery. As mTBI gains recognition as a serious public health epidemic, there is need to identify risk factors, diagnostic tools, and imaging biomarkers to help guide diagnosis and management. Methods: One hundred and eleven patients (15-50 years old) were enrolled acutely after mTBI and followed with up to four standardized serial assessments over 3 months. Each encounter included a clinical exam, neuropsychological assessment, and magnetic resonance imaging (MRI). Chi-square and linear mixed models were used to assess changes over time and determine potential biomarkers of mTBI severity and outcome. Results: The symptoms most frequently endorsed after mTBI were headache (91%), not feeling right (89%), fatigue (86%), and feeling slowed down (84%). Of the 104 mTBI patients with a processed MRI scan, 28 (27%) subjects had white matter changes which were deemed unrelated to age, and 26 of these findings were deemed unrelated to acute trauma. Of the neuropsychological assessments tested, 5- and 6-Digit Backward Recall, the modified Balance Error Scoring System (BESS), and Immediate 5-Word Recall significantly improved longitudinally in mTBI subjects and differentiated between mTBI subjects and controls. Female sex was found to increase symptom severity scores (SSS) at every time point. Age ≥ 25 years was correlated with increased SSS. Subjects aged ≥ 25 also did not improve longitudinally on 5-Digit Backward Recall, Immediate 5-Word Recall, or Single-Leg Stance of the BESS, whereas subjects < 25 years improved significantly. Patients who reported personal history of depression, anxiety, or other psychiatric disorder had higher SSS at each time point. Conclusions: The results of this study show that 5- and 6-Digit Backward Recall, the modified BESS, and Immediate 5-Word Recall should be considered useful in demonstrating cognitive and vestibular improvement during the mTBI recovery process. Clinicians should take female sex, older age, and history of psychiatric disorder into account when managing mTBI patients. Further study is necessary to determine the true prevalence of white matter changes in people with mTBI.

Convergent, Discriminant, and Concurrent Validity of Nonmemory-Based Performance Validity Tests

To supplement memory-based Performance Validity Tests (PVTs) in identifying noncredible performance, we examined the validity of the two most commonly used nonmemory-based PVTs—Dot Counting Test (DCT) and Wechsler Adult Intelligence Scale–Fourth edition (WAIS-IV) Reliable Digit Span (RDS)—as well as two alternative WAIS-IV Digit Span (DS) subtest PVTs. Examinees completed DCT, WAIS-IV DS, and the following criterion PVTs: Test of Memory Malingering, Word Memory Test, and Word Choice Test. Validity groups were determined by passing 3 (valid; n = 69) or failing ⩾2 (noncredible; n = 30) criterion PVTs. DCT, RDS, RDS–Revised (RDS-R), and WAIS-IV DS Age-Corrected Scaled Score (ACSS) were significantly correlated (but uncorrelated with memory-based PVTs). Combining RDS, RDS-R, and ACSS with DCT improved classification accuracy (particularly for DCT/ACSS) for detecting noncredible performance among valid-unimpaired, but largely not valid-impaired examinees. Combining DCT with ACSS may uniquely assess and best supplement memory-based PVTs to identify noncredible neuropsychological test performance in cognitively unimpaired examinees.

Single cell molecular alterations reveal target cells and pathways of concussive brain injury

The complex neuropathology of traumatic brain injury (TBI) is difficult to dissect, given the convoluted cytoarchitecture of affected brain regions such as the hippocampus. Hippocampal dysfunction during TBI results in cognitive decline that may escalate to other neurological disorders, the molecular basis of which is hidden in the genomic programs of individual cells. Using the unbiased single cell sequencing method Drop-seq, we report that concussive TBI affects previously undefined cell populations, in addition to classical hippocampal cell types. TBI also impacts cell type-specific genes and pathways and alters gene co-expression across cell types, suggesting hidden pathogenic mechanisms and therapeutic target pathways. Modulating the thyroid hormone pathway as informed by the T4 transporter transthyretin Ttr mitigates TBI-associated genomic and behavioral abnormalities. Thus, single cell genomics provides unique information about how TBI impacts diverse hippocampal cell types, adding new insights into the pathogenic pathways amenable to therapeutics in TBI and related disorders.

Premorbid IQ Predicts Postconcussive Symptoms in OEF/OIF/OND Veterans with mTBI

Objective

Extant literature has demonstrated that symptoms of postconcussive syndrome (PCS) persist well beyond the expected 3-month post-injury recovery period in a minority of individuals with mild traumatic brain injury (mTBI). Suboptimal performance on validity measures and pre- and post-injury psychosocial stressors - rather than actual mTBI or current cognitive functioning - have been identified as predictors of chronic PCS. Whether premorbid IQ has any influence on chronic PCS has been understudied, in the context of established psychogenic etiologies.

Method

The sample included 31 veterans, who underwent mTBI neuropsychological evaluations six or more months post-injury in a VA outpatient neuropsychology clinic. A two-step multiple linear regression was conducted to examine the effects on the outcome variable, PCS (Neurobehavioral Symptom Inventory), of the following predictors: cognitive functioning (Repeatable Battery for the Assessment of Neuropsychological Status; Attention, Immediate Memory, and Delayed Memory Indices), performance validity, depression (Beck Depression Inventory-Second Edition), posttraumatic stress disorder (PTSD Checklist, Civilian Version), quality of sleep (Pittsburgh Sleep Quality Index), pain (Brief Pain Inventory), education, and Premorbid IQ (Wechsler Test of Adult Reading).

Results

The overall regression model containing all nine predictor variables was statistically significant. Depression (p < .05) and premorbid IQ (p < .05) were the most salient predictors of chronic PCS; in that lower premorbid IQ and greater endorsed symptoms of depression were associated with higher PCS scores. In Step 2 of the multiple linear regression, the WTAR explained an additional 6.7% of the variance in PCS after controlling for psychosocial stressors and current cognitive ability.

Conclusion

The findings support premorbid IQ as a unique and relevant predictor of chronic PCS, with significance variance accounted for beyond education, cognitive functioning, and psychosocial variables. Given the predictive relationship between premorbid IQ and PCS, adapting postconcussive interventions to meet the specific needs of individuals with varying levels of intellect may be important in minimizing ongoing symptomatology.

Saccadic impairment in chronic traumatic brain injury: examining the influence of cognitive load and injury severity

OBJECTIVE

Previous research suggests that saccadic eye movements can be uniquely sensitive to impairment in chronic traumatic brain injury (TBI). This study was conducted to examine saccadic eye movements across varying levels of cognitive load and TBI history/severity. We hypothesized that saccadic impairment in chronic mild and moderate-severe TBI would be most pronounced under conditions of high cognitive load.

METHODS

In total, 61 participants (including n = 20 with chronic mild TBI, n = 15 with chronic moderate-severe TBI, and 26 uninjured controls) completed a battery of conventional neuropsychological tests and the Fusion n-Back Test, which measures manual and saccadic response time (RT) across varying cognitive load and cueing conditions.

RESULTS

Consistent with our hypotheses, chronic mild and moderate-severe TBI were associated with substantial saccadic impairment under conditions of high cognitive load. Participants with moderate-severe TBI also demonstrated saccadic impairment at low levels of cognitive load. TBI groups and uninjured controls did not differ significantly on manual metrics or conventional neuropsychological measures.

CONCLUSIONS

This study provides additional support for the value of eye tracking for enhanced assessment of TBI. Additionally, findings suggest that TBI is associated with greatest susceptibility to oculomotor interference under high levels of cognitive load.

Exploring the factor structure of a battery of neuropsychological assessments among the CENC cohort

OBJECTIVE

The goal of the Chronic Effects of Neurotrauma Consortium (CENC) study is to explore the effects of concussions among Service Members and Veterans. A factor model was fit to selected neuropsychological measures to identify potentially useful relationships between assessments collected on CENC-enrolled participants.

METHOD

492 post-9/11 participants with combat exposure were enrolled across four VA study sites. Participants completed assessments including concussion history, neurocognitive functioning, and self-report questionnaires. Exploratory factor analyses (EFA) using four different methods with varimax and promax rotations were used to analyse the cognitive variables. Final model selection was based on factor loadings towards simple structure.

RESULTS

The scree plot suggested the number of factors to be extracted was between 4 and 5. EFA produced a 5-factor MINRES model with promax rotation that resulted in a factor loading with variables loading on only one factor with a predefined threshold (0.40). Variables loaded on five cognition domains: list learning, working memory/executive skills, cognitive control, fluency, and memory.

CONCLUSION

These results provide reasonable evidence that data collected from the CENC neuropsychological battery can be reduced to five clinically useful factors. This will enable us to use the factors for further study of the impact of concussion on neurodegeneration.

Unique Aspects of Traumatic Brain Injury in Military and Veteran Populations

Traumatic brain injury (TBI), in particular mild TBI (mTBI), is a relatively common injury experienced by service members across both deployed and nondeployed environments. Although many of the principles and practices used by civilian health care providers for identifying and treating this injury apply to military settings, there are unique factors that impact mTBI-related care in service members and Veterans. This article reviews several of these factors, including the epidemiology of TBI in the military/Veteran population, the influence of military culture on this condition, and identification and treatment of mTBI in the war zone.

Retrospective and Prospective Memory Among OEF/OIF/OND Veterans With a Self-Reported History of Blast-Related mTBI

OBJECTIVES

To evaluate prospective and retrospective memory abilities in Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF), and Operation New Dawn (OND) Veterans with and without a self-reported history of blast-related mild traumatic brain injury (mTBI).

METHODS

Sixty-one OEF/OIF/OND Veterans, including Veterans with a self-reported history of blast-related mTBI (mTBI group; n=42) and Veterans without a self-reported history of TBI (control group; n=19) completed the Memory for Intentions Test, a measure of prospective memory (PM), and two measures of retrospective memory (RM), the California Verbal Learning Test-II and the Brief Visuospatial Memory Test-Revised.

RESULTS

Veterans in the mTBI group exhibited significantly lower PM performance than the control group, but the groups did not differ in their performance on RM measures. Further analysis revealed that Veterans in the mTBI group with current PTSD (mTBI/PTSD+) demonstrated significantly lower performance on the PM measure than Veterans in the control group. PM performance by Veterans in the mTBI group without current PTSD (mTBI/PTSD-) was intermediate between the mTBI/PTSD+ and control groups, and results for the mTBI/PTSD- group were not significantly different from either of the other two groups.

CONCLUSIONS

Results suggest that PM performance may be a sensitive marker of cognitive dysfunction among OEF/OIF/OND Veterans with a history of self-reported blast-related mTBI and comorbid PTSD. Reduced PM may account, in part, for complaints of cognitive difficulties in this Veteran cohort, even years post-injury. (JINS, 2018, 24, 324-334).

Chronic traumatic encephalopathy in sports: a historical and narrative review

My objectives are to review: 1) a brief history of sport-related concussion (SRC) and chronic traumatic encephalopathy (CTE), 2) the evolution of CTE in American professional football, 3) the data regarding SRC/CTE as they relate to depression and suicide, 4) the data on the neurocognitive effects of subconcussion/repetitive head trauma (with emphases on heading the ball in soccer and early exposure to football), 5) the evidence related to SRC and neurodegenerative diseases, 6) the published studies of CTE, 7) the NINDS neuropathological criteria for CTE, 8) public beliefs about SRC/CTE, and 9) the scientific questions regarding CTE.

Neurocognitive Models of Medical Decision-Making Capacity in Traumatic Brain Injury Across Injury Severity

OBJECTIVE

To identify neurocognitive predictors of medical decision-making capacity (MDC) in participants with mild and moderate/severe traumatic brain injury (TBI).

SETTING

Academic medical center.

PARTICIPANTS

Sixty adult controls and 104 adults with TBI (49 mild, 55 moderate/severe) evaluated within 6 weeks of injury.

DESIGN

Prospective cross-sectional study.

MAIN MEASURES

Participants completed the Capacity to Consent to Treatment Instrument to assess MDC and a neuropsychological test battery. We used factor analysis to reduce the battery test measures into 4 cognitive composite scores (verbal memory, verbal fluency, academic skills, and processing speed/executive function). We identified cognitive predictors of the 3 most clinically relevant Capacity to Consent to Treatment Instrument consent standards (appreciation, reasoning, and understanding).

RESULTS

In controls, academic skills (word reading, arithmetic) and verbal memory predicted understanding; verbal fluency predicted reasoning; and no predictors emerged for appreciation. In the mild TBI group, verbal memory predicted understanding and reasoning, whereas academic skills predicted appreciation. In the moderate/severe TBI group, verbal memory and academic skills predicted understanding; academic skills predicted reasoning; and academic skills and verbal fluency predicted appreciation.

CONCLUSIONS

Verbal memory was a predictor of MDC in controls and persons with mild and moderate/severe TBI. In clinical practice, impaired verbal memory could serve as a "red flag" for diminished consent capacity in persons with recent TBI.

Persistent symptoms and activity changes three months after mild traumatic brain injury

BACKGROUND/AIM

Approximately, 80% of traumatic brain injuries are considered mild in severity. Mild traumatic brain injury (mTBI) may cause temporary or persisting impairments that can adversely affect an individual's ability to participate in daily occupations and life roles. This study aimed to identify symptoms, factors predicting level of symptoms and functional and psycho-social outcomes for participants with mTBI three months following injury.

METHOD

Patients discharged from the Emergency Department of a major metropolitan hospital with a diagnosis of mTBI were contacted by telephone three months after injury. An interview with two questionnaires was administered: The Concussion Symptom Inventory (CSI) Scale and the Rivermead Head Injury Follow-Up Questionnaire (RHIFUQ). Data obtained were used to determine the type and prevalence of post-concussion symptoms and their impact on activity change.

RESULTS

Sixty-three people with mTBI participated in the study. The majority of participants (81%) reported that all symptoms had resolved within the three-month time frame. Of those still experiencing symptoms, workplace fatigue (22%) and an inability to maintain previous workload/standards (17%) were reported.

CONCLUSION

There is a small, but clinically significant, subgroup of patients who continue to experience symptoms three-month post-mTBI. Symptoms experienced beyond the expected three-month recovery timeframe have the potential to adversely affect an individual's ability to participate in daily occupation and return to work.

Assessing the effects of concussion using the C3Logix Test Battery: An exploratory study

The C3Logix is a computerized concussion assessment tool that measures a wider array of symptoms (i.e., balance and oculomotor functioning) than other computerized batteries. Although the C3Logix has been used increasingly by athletic organizations at all levels of play, its utility within the concussion population has not been extensively examined. The current study aimed to determine whether the C3Logix is sensitive to the effects of concussion. A total of 54 student-athletes enrolled at a large southern university completed the C3Logix at baseline and within days following a suspected concussion (mean = 2.93, SD = 3.14). Dependent-samples t-tests revealed that relative to their baselines, following concussion, athletes both reported significantly greater postconcussive symptoms and performed more poorly on measures of reaction time and computer-measured balance. Decrements in processing speed, visual acuity, and clinician-observed errors on tests of balance also trended toward significance. Results suggest that inclusion of measures of balance and oculomotor functioning in the assessment of concussion may provide additional clinical utility above and beyond domains typically measured by computerized concussion assessments.

Use of general practice before and after mild traumatic brain injury: a nationwide population-based cohort study in Denmark

OBJECTIVES

Traumatic brain injury (TBI) is commonly seen in the emergency department (ED). Approximately 85%-90% of TBIs are mild (mTBI). Some cause symptoms such as headache, dizziness, anxiety, blurred vision, insomnia and concentration difficulties, collectively known as postconcussion syndrome (PCS). Some studies suggest that recovery from mTBI is complete. Others find that symptoms persist for months, even years. The aim of this study was to describe the use of general practice, before and after mTBI, as a proxy for symptoms in a large cohort.

DESIGN

Nationwide population-based matched cohort study.

SETTING

Danish EDs and general practice.

PARTICIPANTS

All patients (aged ≥18 years), first-time diagnosed with mTBI in a Danish ED between 1 January 1998 and 31 December 2010 (n=93 517). Ten reference persons per patient with mTBI were randomly matched on gender, age and general practice (n=935 170).

PRIMARY OUTCOME

Overall use of general practice; consultations relating to mental and physical health.

RESULTS

We found higher use of general practice during the first year after mTBI for all ages, both genders and all types of contacts. Age 18-40 years: women, incidence rate ratio (IRR) 1.59 (95% CI 1.57 to 1.61); men, IRR 1.82 (95% CI 1.80 to 1.85). Age 41-65 years: women, IRR 1.75 (95% CI 1.72 to 1.78); men, IRR 1.85(95% CI 1.82 to 1.89). Age 66+ years: women, IRR 1.55 (95% CI 1.52 to 1.58); men, IRR 1.55 (95% CI 1.51 to 1.59). After the first year, the use decreased to the level before mTBI. Individuals with mTBI and higher use of general practice before mTBI had lower socioeconomic status and more comorbidities (P<0.001).

CONCLUSIONS

The use of general practice was higher in the first year after mTBI, specifically in the first 3 months. Patients with mTBI had different healthcare-seeking behaviour several years before diagnosis than their matched reference persons. Pretraumatic morbidity should be considered in the evaluation of PCS.

Concussion knowledge among rehabilitation staff

A concussion knowledge survey was completed by 561 rehabilitation professionals across a wide range of disciplines in a nationwide rehabilitation hospital system. Item questions were structured to reflect key areas of concussion knowledge targeted in a prior consensus statement. The vast majority of staff provided responses consistent with the current concussion literature regarding concussion diagnosis and symptom presentation immediately after concussion. Greater variability was seen for items assessing beliefs about the typical recovery from concussion, best care practices, and long-term effects from concussion. Factors such as profession, years of experience, and work with concussion or traumatic brain injury were not consistently related to better performance on the survey. Prior concussion-focused education/training was related to better survey performance. This survey highlights the pressing need to educate frontline health providers regarding concussion recovery and best care practices.