The Postconcussion Syndrome and Posttraumatic Headaches in Civilians, Soldiers, and Athletes

Posttraumatic headaches are one of the most common and controversial secondary headache types. After a mild traumatic brain, an estimated 11% to 82% of people develop a postconcussion syndrome, which has been controversial for more than 160 years. Headache is estimated as present in 30% to 90% of patients after a mild head injury. Most headaches are tension-type-like or migraine-like. Headaches in civilians, soldiers, athletes, and postcraniotomy are reviewed. The treatments are the same as for the primary headaches. Persistent posttraumatic headaches can continue for many years.

Factors perpetuating functional cognitive symptoms after mild traumatic brain injury

INTRODUCTION

Self-reported memory difficulties (forgetting familiar names, misplacing objects) often persist long after a mild traumatic brain injury (mTBI), despite normal neuropsychological test performance. This clinical presentation may be a manifestation of a functional cognitive disorder (FCD). Several mechanisms underlying FCD have been proposed, including metacognitive impairment, memory perfectionism, and misdirected attention, as well as depression or anxiety-related explanations. This study aims to explore these candidate perpetuating factors in mTBI, to advance our understanding of why memory symptoms frequently persist following mTBI.

METHODS

A cross-sectional study of 67 adults (n = 39 with mTBI mean = 25 months ago and n = 28 healthy controls). Participants completed standardized questionnaires (including the Functional Memory Disorder Inventory), a metacognitive task (to quantify discrepancies between their trial-by-trial accuracy and confidence), and a brief neuropsychological test battery. We assessed candidate mechanisms in two ways: (1) between-groups, comparing participants with mTBI to healthy controls, and (2) within-group, examining their associations with functional memory symptom severity (FMDI) in the mTBI group.

RESULTS

Participants with mTBI performed similarly to controls on objective measures of memory ability but reported experiencing much more frequent memory lapses in daily life. Contrary to expectations, metacognitive efficiency did not differentiate the mTBI and control groups and was not associated with functional memory symptoms. Memory perfectionism was strongly associated with greater functional memory symptoms among participants with mTBI but did not differ between groups when accounting for age. Depression and checking behaviors produced consistent results across between-groups and within-group analyses: these factors were greater in the mTBI group compared to the control group and were associated with greater functional memory symptoms within the mTBI group.

CONCLUSIONS

This study highlights promising (e.g., depression, checking behaviors) and unlikely (e.g., metacognitive impairment) mechanisms underlying functional memory symptoms after mTBI, to guide future research and treatment.

Research hotspots and trends on sports medicine of athletes: A scientometric analysis from 2003 to 2023

This study aims to demonstrate current research priorities and predict future trends of sports medicine of athletes by scientometric analysis. We collected nearly 20 years (2003 to 2023) of publications related to Sports medicine of athletes in the Web of Science database, Citespace was applied to evaluate the knowledge mapping. There are 4820 manuscripts about post-cesarean section in total, and faster growth after 2018. The country, institution, and author posted the most are the USA, Harvard University, and Engebretsen, Lars. Brit J Sport Med publishes the most articles of this type. In addition, the most key cited reference is Hopkins WG (2009). Sports medicine of athletes research, including blood, biomedical imaging informatics, and activity monitor has been a research hotspots in recent years. Through scientometric analysis of the past 20 years, we know the blood, biomedical imaging informatics, and activity monitor is the focus of future research. The USA, Australia, and England have become the main research forces in this field with high publication rates and centrality. This is important for accurately and quickly locating trends in this field.

Elevated C-reactive protein-to-albumin ratio with fever is a predictor of poor functional outcome in patients with mild traumatic brain injury

Introduction

The C-reactive protein -to-albumin ratio (CAR), a novel inflammation-based prognostic score, is useful in predicting clinical outcomes, including those in central nervous system diseases. However, no report has identified the relationship between CAR and long-term clinical outcomes in patients with mild traumatic brain injury (mTBI). We aimed to evaluate the relationship between CAR and long-term functional outcomes in patients with mTBI and analyze whether CAR is associated with the presence of fever.

Methods

This was a retrospective observational study includes 387 adult patients with mTBI who were treated at a level-1 trauma center between 2017 and 2021. The main exposure variable was an elevated CAR, and the main outcomes were degrees of disability and quality of life measured using the modified Rankin Scale (mRS). A multivariable logistic regression analysis was performed to estimate the effect size of CAR on study outcomes. An interaction analysis was performed between CAR and fever on study outcomes.

Results

Elevated CAR had no significant association with poor functional outcomes (aOR [95% CI]: 1.35 [0.39-4.69]) in patients with mTBI. In the interaction analysis, elevated CAR was not associated with increased poor functional outcomes in the absence of fever (1.08 [0.55-2.13]), but a significant increase in poor functional outcomes was observed when elevated CAR was accompanied by fever (1.32 [1.14-2.56)).

Conclusions

Elevated CAR with fever increased the risk of poor functional recovery at 6 months after hospital discharge in patients with mTBI. Our study findings suggest the need for strategies for the prevention of long-term poor functional recovery in the presence of high CAR and fever in patients with mTBI.

Unexpected symptoms after concussion: Potential links to functional neurological and somatic symptom disorders

OBJECTIVE

Reporting of unexpected symptoms after concussion might, in some people, reflect a Functional Neurological Disorder (FND), Somatic Symptom Disorder (SSD), or exaggeration (feigning). This study aimed to determine whether reporting unexpected symptoms after concussion was associated with risk factors for FND/SSD, exaggeration, or both.

METHOD

Adults with persistent symptoms following concussion (N = 77; 61% women) rated the presence and severity of unexpected neurological symptoms (from the Screening for Somatoform Symptoms scale, e.g., paralysis) and somatic symptoms (from the Patient Health Questionnaire-15, e.g., stomach pain) that did not overlap with post-concussion symptom scale items. The independent variables were risk factors for exaggeration (neuropsychological performance validity test failure and personal injury litigation) and predisposing and perpetuating factors for developing FND and/or SSD (e.g., fear avoidance behavior).

RESULTS

When adjusting for all covariates, fear avoidance behavior was most strongly related to unexpected neurological symptoms (B = 0.11, 95% confidence interval = 0.05-0.18, p < .001), while current anxiety scores were most strongly related to unexpected somatic symptoms (B = 0.34, 95% confidence interval = 0.15-0.52, p < .001). Performance validity test failure and litigation were not significant predictors in either model.

CONCLUSION

Unexpected neurological and other somatic symptoms after concussion should not be dismissed as exaggeration. Psychological factors thought to perpetuate FND and SSD (e.g., fear avoidance behavior) may contribute to unexpected symptoms following concussion. More research is needed at the intersection of FND, SSD, and persistent post-concussive symptoms.

Relationship between Dizziness and the Core Vestibular Projection Injury in Patients with Mild Traumatic Brain Injury

Some studies have reported that a core vestibular projection (CVP) injury is associated with dizziness following a brain injury using diffusion tensor tractography (DTT). On the other hand, there has been no DTT study on dizziness caused by a CVP injury in patients with mild traumatic brain injury (TBI). In this study, DTT was used to examine the relationship between dizziness and CVP injury in patients with mild TBI. Forty-three patients with mild TBI and twenty-nine normal subjects were recruited. The patients were classified into two groups based on the dizziness score: group A, patients with a dizziness score less than 2 on the sub-item score for dizziness in the Rivermead Post-concussion Symptoms Questionnaire; group B, patients with a dizziness score above 2. The tract volume (TV) in group B was significantly lower than group A and the control group (p < 0.05). By contrast, the TV in group A was similar to the control group (p > 0.05). Regarding the correlation, the dizziness score of all patients showed a strong negative correlation with the TV of the CVP (r = −0.711, p < 0.05). DTT revealed the CVP injury in patients with dizziness after mild TBI. In addition, the severity of dizziness of these patients was closely related to the injury severity of the CVP.

Photophobia Associated with Traumatic Brain Injury: A Systematic Review and Meta-analysis

SIGNIFICANCE

This study reports the prevalence and relative risk of photophobia in patients with traumatic brain injury (TBI).

OBJECTIVES

This study aimed to conduct a systematic review and meta-analysis to determine the prevalence and relative risk of photophobia in patients with TBI.

DATA SOURCES

Three databases were used for literature search: PubMed, EMBASE, and Cochrane Library.

STUDY APPRAISAL AND SYNTHESIS METHODS

Publications reporting the prevalence of photophobia after TBI in patients of any age were included. A series of meta-regression analyses based on a generalized linear mixed model was performed to identify potential sources of heterogeneity in the prevalence estimates.

RESULTS

Seventy-five eligible publications were identified. The prevalence of photophobia was 30.46% (95% confidence interval [CI], 20.05 to 40.88%) at 1 week after the injury. Prevalence decreased to 19.34% (95% CI, 10.40 to 28.27%) between 1 week and 1 month after TBI and to 13.51% (95% CI, 5.77 to 21.24%) between 1 and 3 months after the injury. The rapid decrease in the prevalence of photophobia in the first 3 months after a TBI injury was significant (P < .001). Three months post-TBI, the prevalence of photophobia leveled off to a near plateau with nonsignificant variability, increasing between 3 and 6 months (17.68%; 95% CI, 9.05 to 26.32%) and decreasing between 6 and 12 months since TBI (14.85%; 95% CI, 6.80 to 22.90%). Subgroup analysis of 14 publications that contained control data showed that the estimated risk ratio for photophobia was significantly higher in the TBI than in the control group during the entire 12 months after TBI.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This study demonstrates that photophobia is a frequent complaint after TBI, which largely resolves for many individuals within 3 months after the injury. For some patients, however, photophobia can last up to 12 months and possibly longer. Developing an objective quantitative methodology for measuring photophobia, validating a dedicated photophobia questionnaire, and having a specific photophobia International Classification of Diseases, Tenth Revision code would greatly improve data gathering and analysis.

Unexpected role of stress as a possible resilience mechanism upon mild traumatic brain injury (mTBI) in mice

INTRODUCTION

Mild traumatic brain injury (mTBI) is common and associated with cognitive impairment. Stress and mTBI are known to modulate the neural function. The present study aims at exploring the effect of prior stress exposure on cognitive function following mTBI.

METHODS

Eight weeks old male ICR mice were subjected to either stress induced by forced swimming stress alone, stress followed by an immediate mTBI, or stress followed by 30 min break and then mTBI. We had two control groups: SHAM group - a control group which was not exposed to stress nor to mTBI and control mTBI group - a control group which was exposed only to TBI with no stress. Mice were weighed prior and at 12, 24 h and 1 week following interventions. Motor evaluation was conducted by rotarod. Behavioral changes were evaluated using open field, Y maze, elevated plus maze and staircase tests, at 12 h and 1 week following interventions. Brain levels of NMDAR subunits (R1, R2A, R2B), GABA_BR1, glucocorticoid and mineralocorticoid receptors (GR, MR) were evaluated using western blot.

RESULTS

Stress alone, mTBI alone, and stress followed by immediate mTBI resulted in a significant weight loss compared to control (p < 0.05). Stress 30 min prior to mTBI had a protective effect on weight (p = 0.14 compared to control). The stress and mTBI alone groups showed reduced time at the center of the open field arena 1 week after intervention (p < 0.05 for both). Time in the novel arm of the Y maze was significantly shorter in the mTBI and stress followed by delayed mTBI (p = 0.02). Immediate stress prior to mTBI had normalized times in the novel arm (p = 0.95 compared to control). Combination of stress and mTBI significantly modified NMDAR subunits levels (increased NMDAR1, p < 0.008, decreased NMDAR2A p = 0.02) as well as increased MR levels (p = 0.04).

CONCLUSION

Exposure to stress prior to mTBI may improve the cognitive consequences of mTBI. These data may point towards a novel, unexpected role of stress as a possible resilience mechanism in the setting of mTBI.

Prognostic factors for unfavorable outcome after mild traumatic brain injury. A review of literature

BACKGROUND

Unfavorable outcomes occur in 15-20% of patients with mild traumatic brain injury (mTBI). Early identification of patients at risk of unfavorable outcome is crucial for suitable management to be initiated, increasing the chances of full recovery. Many studies have been published on prognostic factors, but are not of a high level of evidence and certainty. A number of factors have been proposed and predictive models have been constructed that, although attractive, have not yet been externally validated.

OBJECTIVES

A review of literature (systematic search of PubMed and Google Scholar) assembled relevant available information about prognostic factors for unfavorable outcome after mTBI. We discuss the consistency of these findings, and the possibility and difficulty of using these factors in a daily practice.

RESULTS

It appears that the strongest and most consistent predictors are the number, severity and duration of symptoms present in the first few days after the trauma.

Visual memory performance following mild traumatic brain injury and its relationship with intellectual functioning

To compare the visual memory performance of uncomplicated and complicated mild TBI (mTBI) groups with that of a control group on the Rey Complex Figure Test (RCFT). We also aimed to explore the influence of factors such as age, gender, education, occupation, and intellectual functioning on visual memory in individuals with mTBI. The RCFT and the Wechsler Abbreviated Scale of Intelligence (WASI-II) were administered to 138 participants (90 uncomplicated mTBI patients, 19 complicated mTBI patients, and 29 controls). The mTBI patients demonstrated significantly lower scores than control participants on both immediate and delayed RCFT recall conditions, with performance in the low average and borderline range. However, there was no difference in performance between the two mTBI groups on the recall conditions. In addition, no significant differences were observed across the three groups on the recognition condition. The WASI-II Performance and Verbal IQ scales explained most of the variance in the immediate and delayed RCFT recall conditions but were not associated with performance on the recognition condition. In contrast with the recognition processes involved in visual memory, recall processes seem to be more vulnerable following mTBI and both verbal and performance IQ seem to be related to visual memory performance.

Effects of Media Sensationalization on Cognitive Performance and Post Concussive Symptoms

OBJECTIVES

The current study aimed to examine if televised media about mild traumatic brain injury (mTBI) framed in a sensationalized manner had a negative impact on cognitive functioning and persistent mTBI symptoms.

METHODS

One hundred two participants (M Age=37.16; SD=22.61) with a history of post-acute mTBI, recruited through a community research registry and an undergraduate recruitment system, were included in this study. Participants were assessed with a measure of health literacy, the Short Test of Functional Health Literacy in Adults (S-TOFHLA), and randomized to watch either a sensationalized or non-sensationalized news clip focused on mTBI. They were then assessed with the Paced Auditory Serial Addition Test (PASAT), Rivermead Post Concussion Symptoms Questionnaire (RPQ), Patient Reported Outcome Measures Information System (PROMIS) Depression scale, and the Posttraumatic Stress Disorder Checklist for the Diagnostic and Statistical Manual of Mental Disorders 5th edition (PCL-5).

RESULTS

Bayesian analyses indicated that sensationalized media-alone (β PASAT=-0.08; β RPQ=-0.08) or in the context of covariates (β PASAT=-0.11; β RPQ=-0.14)-was not a strong predictor of PASAT score or post-concussion syndrome symptom severity.

CONCLUSIONS

Although media sensationalization of mTBI symptoms is not desirable, this study suggests that one brief exposure to sensationalized information may not have a meaningful immediate impact on the cognitive functioning or symptom reporting of individuals with a history of mTBI. Future research should examine long-term and downstream effects of sensationalized media reporting in samples with greater diversity of TBI history. (JINS, 2019, 25, 90-100).

Impact & Blast Traumatic Brain Injury: Implications for Therapy

Traumatic brain injury (TBI) is one of the most frequent causes of combat casualties in Operations Iraqi Freedom (OIF), Enduring Freedom (OEF), and New Dawn (OND). Although less common than combat-related blast exposure, there have been significant numbers of blast injuries in civilian populations in the United States. Current United States Department of Defense (DoD) ICD-9 derived diagnoses of TBI in the DoD Health Care System show that, for 2016, severe and moderate TBIs accounted for just 0.7% and 12.9%, respectively, of the total of 13,634 brain injuries, while mild TBIs (mTBIs) accounted for 86% of the total. Although there is a report that there are differences in the frequency of long-term complications in mTBI between blast and non-blast TBIs, clinical presentation is classified by severity score rather than mechanism because severity scoring is associated with prognosis in clinical practice. Blast TBI (bTBI) is unique in its pathology and mechanism, but there is no treatment specific for bTBIs-these patients are treated similarly to TBIs in general and therapy is tailored on an individual basis. Currently there is no neuroprotective drug recommended by the clinical guidelines based on evidence.

The association between microhaemorrhages and post - traumatic functional outcome in the chronic phase after mild traumatic brain injury

PURPOSE

In the chronic phase after mild traumatic brain injury (mTBI), microhaemorrhages are frequently detected on magnetic resonance imaging (MRI). It is however unclear whether microhaemorrhages are associated with functional outcome and which MRI sequence is most appropriate to address this association. We aimed to determine the association between microhaemorrhages and functional outcome in the chronic posttraumatic phase after injury with the most suitable MRI sequence to address this association.

METHODS

One hundred twenty-seven patients classified with mTBI admitted to the outpatient clinic from 2008 to 2015 for persisting posttraumatic complaints were stratified according to the presence of MRI abnormalities (n = 63 (MRI+ group) and n = 64 without abnormalities (MRI- group)). For the detection of microhaemorrhages, susceptibility-weighted imaging (SWI) and T2* gradient recalled echo (T2*GRE) were used. The relation between the functional outcome (dichotomized Glasgow Outcome Scale Extended scores) and the number and localization of microhaemorrhages was analysed using binary logistic regression.

RESULTS

SWI detected twice as many microhaemorrhages compared to T2*GRE: 341 vs. 179. Lesions were predominantly present in the frontal and temporal lobes. Unfavourable outcome was present in 67% of the MRI+ group with a significant association of total number of microhaemorrhages in the temporal cortical area on SWI (OR 0.43 (0.21-0.90) p = 0.02), with an explained variance of 44%. The number of microhaemorrhages was not correlated with the number of posttraumatic complaints.

CONCLUSION

An unfavourable outcome in the chronic posttraumatic phase is associated with the presence and number of microhaemorrhages in the temporal cortical area. SWI is preferably used to detect these microhaemorrhages.

Exploring the Relationship Between Mild Traumatic Brain Injury Exposure and the Presence and Severity of Postconcussive Symptoms Among Veterans Deployed to Iraq and Afghanistan

OBJECTIVE

The aim of this study was to describe the association between mild traumatic brain injury (mTBI) and persisting postconcussive symptoms according to symptom category, number, and severity.

DESIGN

The study design was observational.

PARTICIPANTS

The study sample comprised veterans (≥18 years of age) deployed in Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF) conflicts who had not received any treatment for mTBI in the 30 days preceding study enrollment.

METHODS

Veterans were interviewed and completed testing in a single day. The Standard TBI Diagnostic Interview and the Clinician-Administered PTSD Scale were used. Testing included the Neurobehavioral Symptom Inventory and a full neuropsychological battery. Gold standard classification methods were utilized to determine presence/absence of mTBI. For each of the 5 symptom outcomes, an adjusted multiple linear regression model (negative binomial count models) accounting for effects of socio-demographic variables and behavioral health conditions was used.

MAIN OUTCOME MEASURES

Self-report of neurobehavioral symptoms categorized as affective, cognitive, somatic, and vestibular symptoms, in addition to the instruments specified above.

RESULTS

OEF/OIF veterans with mTBI, relative to veterans with no mTBI, were observed to have 30% more symptoms overall (P < .001), 34% more somatic symptoms (P < .001), 22% more cognitive symptoms (P = .008), 15% more affective symptoms (P = .017), and 59% more vestibular symptoms (P < .001). For adjusted models, variables significantly related to number of symptoms across all 4 symptom categories were anxiety (all P < .001) and insomnia (all P < .001). For the adjusted models, variables significantly related to symptom severity across all 4 symptom categories were insomnia (all P < .001), depression (P < .001-.05) and anxiety (all, P < .001).

CONCLUSIONS

OEF/OIF veterans with mTBI, relative to veterans with no mTBI, have significantly more and significantly more severe persisting symptoms, with vestibular symptoms reported with the greatest frequency. After accounting for behavioral health conditions and socio-demographic factors, OEF/OIF veterans with mTBI compared to veterans without mTBI had significantly more cognitive, affective, vestibular, and somatic symptoms persisting 4.8 years after the mTBI event(s).

Elevated C-reactive protein levels may be a predictor of persistent unfavourable symptoms in patients with mild traumatic brain injury: a preliminary study

The pathogenesis of persistent unfavourable outcomes following mild traumatic brain injury (mTBI) are not fully understood. Low-grade systemic inflammation might contribute to the development of persistent unfavourable outcomes in patients with mTBI. We used plasma high-sensitivity C-reactive protein (CRP) levels as the biomarker of systemic inflammation to investigate whether elevated CRP levels were associated with persistent adverse outcomes in these patients. A total of 213 consecutive patients with mTBI were identified in our study. Plasma high-sensitivity CRP levels were measured at baseline, 1month, 2months and 3months after initial traumatic brain injury. The study endpoints included persistent postconcussion syndrome (PCS), persistent psychological problems (depression and anxiety), persistent physiological problems (frequent headache, nausea, insomnia, dizziness and fatigue) and persistent cognitive impairment, which were screened by International Classification of Diseases (ICD-10), diagnostic and statistical manual of mental disorders (DSM-IV), Beck anxiety inventory (BAI), Beck depression inventory (BDI) and montreal cognitive assessment (MoCA) 3months post-injury. The associations between baseline CRP levels and persistent unfavourable outcomes were estimated from multiple regression models adjusting for various confounding covariates. Elevated baseline CRP levels were associated with a significant increase in the incidence of persistent PCS (odds ratio [OR], 2.719; 95% confidence interval [CI], 1.609-4.594; p=0.000), persistent psychological problems (OR, 1.535; 95% CI, 1.063-2.216; p=0.022), and persistent cognitive impairment (OR, 1.687; 95% CI, 1.135-2.507; p=0.010). However, elevated CRP levels were not associated with persistent physiological problems (OR, 1.330; 95% CI, 0.905-1.956; p=0.146). Furthermore, three adjusted models did not essentially affect the OR of elevated CRP levels for these persistent unfavourable outcomes. Among patients with mTBI, baseline elevated CRP levels may be an independent predictor of persistent persistent PCS, psychological problems and cognitive impairment.

Predictors of neurobehavioral symptoms in a university population: a multivariate approach using a postconcussive symptom questionnaire

Several factors have been linked to severity of postconcussive-type (neurobehavioral) symptoms. In this study, predictors of neurobehavioral symptoms were examined using multivariate methods to determine the relative importance of each. Data regarding demographics, symptoms, current alcohol use, history of traumatic brain injury (TBI), orthopedic injuries, and psychiatric/developmental diagnoses were collected via questionnaire from 3027 university students. The most prominent predictors of symptoms were gender, history of depression or anxiety, history of attention-deficit/hyperactivity disorder or learning disability diagnosis, and frequency of alcohol use. Prior mild TBI was significantly related to overall symptoms, but this effect was small in comparison to other predictors. These results provide further evidence that neurobehavioral symptoms are multi-determined phenomena, and highlight the importance of psychiatric comorbidity, demographic factors, and health behaviors to neurobehavioral symptom presentation after mild TBI.

Neuropsychological outcomes of U.S. Veterans with report of remote blast-related concussion and current psychopathology

This study explored whether remote blast-related MTBI and/or current Axis I psychopathology contribute to neuropsychological outcomes among OEF/OIF veterans with varied combat histories. OEF/OIF veterans underwent structured interviews to evaluate history of blast-related MTBI and psychopathology and were assigned to MTBI (n = 18), Axis I (n = 24), Co-morbid MTBI/Axis I (n = 34), or post-deployment control (n = 28) groups. A main effect for Axis I diagnosis on overall neuropsychological performance was identified (F(3,100) = 4.81; p = .004), with large effect sizes noted for the Axis I only (d = .98) and Co-morbid MTBI/Axis I (d = .95) groups relative to the control group. The latter groups demonstrated primary limitations on measures of learning/memory and processing speed. The MTBI only group demonstrated performances that were not significantly different from the remaining three groups. These findings suggest that a remote history of blast-related MTBI does not contribute to objective cognitive impairment in the late stage of injury. Impairments, when present, are subtle and most likely attributable to PTSD and other psychological conditions. Implications for clinical neuropsychologists and future research are discussed. (JINS, 2012, 18, 1-11).

Mild traumatic brain injury results in extensive neuronal degeneration in the cerebral cortex

Mild traumatic brain injury (mTBI) leads to long-term cognitive and emotional difficulties and behavioral disturbances, but the diagnosis and treatment of mTBI have historically been hampered by a lack of evidence-based correlates of these clinical manifestations. Unlike moderate and severe TBI, mTBI does not show significant tissue lesions or cavities in the cortex. Moreover, neuroimaging by magnetic resonance imaging or computed tomography is usually negative, suggesting that the damage is beyond the resolution of current structure-based scanning technologies. Therefore, we investigated the morphologies of spared neurons in the mouse cortex after mTBI in a controlled cortical impact injury model. Our results indicate that, although mTBI caused only a mild extent of cell death, it led to extensive dendrite degeneration and synapse reduction in the cortex in this model. This study sheds light on the neuropathologic consequences of mTBI in humans and suggests that neurodegeneration may be a novel target for developing diagnostic methods and therapeutic approaches for mTBI.

Neuropsychological evaluation of blast-related concussion: illustrating the challenges and complexities through OEF/OIF case studies

BACKGROUND/OBJECTIVE

Soldiers of Operations Enduring Freedom (OEF) and Iraqi Freedom (OIF) sustain blast-related mild traumatic brain injury (concussion) with alarming regularity. This study discusses factors in addition to concussion, such as co-morbid psychological difficulty (e.g. post-traumatic stress) and symptom validity concerns that may complicate neuropsychological evaluation in the late stage of concussive injury.

CASE REPORT

The study presents the complexities that accompany neuropsychological evaluation of blast concussion through discussion of three case reports of OEF/OIF personnel.

DISCUSSION

The authors emphasize uniform assessment of blast concussion, the importance of determining concussion severity according to acute-injury characteristics and elaborate upon non-concussion-related factors that may impact course of cognitive limitation. The authors conclude with a discussion of the need for future research examining the impact of blast concussion (particularly recurrent concussion) and neuropsychological performance.

Persistent symptoms associated with factors identified by the WHO Task Force on Mild Traumatic Brain Injury

The current study examined the role of factors identified by the World Health Organization's Task Force on Mild Traumatic Brain Injury as being associated with poor outcome after mild traumatic brain injury. Employing symptom severity ratings at 3 months post-injury greater than "mild," subgroups of Higher-Severity (20%) and Lower-Severity (80%) participants were identified. Findings revealed that individuals who report greater symptom complaints at 3 months post-MTBI may be identifiable soon after injury on the basis of the magnitude and severity of early self-reported symptoms, pre-morbid psychological issues, and involvement in compensation-seeking. Injury severity factors did not differ between the groups.

The significance of mild traumatic brain injury to cognition and self-reported symptoms in long-term recovery from injury

The aim of this study was to evaluate neurocognition and self-reported symptoms in long-term recovery from mild traumatic brain injury (mild TBI). Participants' time since injury ranged from 3 to 72 (M = 36.75) months. Relative to orthopedic injury controls (n = 63), mild TBI participants (n = 63) did not demonstrate cognitive impairment in any domains examined, or differences in self-report of postconcussive or psychiatric symptoms. However, postconcussive and psychiatric symptoms were strongly related (r = .50, p < .05). Results provide additional evidence that neurological injury in single-incident mild TBI is of little clinical significance to long-term cognitive and symptom outcome.

Correlates of persistent postconcussional disorder: DSM-IV criteria versus ICD-10

Controversy surrounding the causation of symptom complaints after mild traumatic brain injury (MTBI) is reflected by the existence of alternative diagnostic criteria for postconcussional syndrome (PCS) in the International Classification of Diseases (ICD) and postconcussional disorder (PCD) in the Diagnostic and Statistical Manual of Mental Disorders-4th edition (DSM-IV). Previous studies of persisting symptoms have employed various symptom checklists rather than uniform criteria-based diagnoses. This is the first prospective study of persisting symptom complaints using the formal diagnostic criteria for PCD and PCS and comparing these criteria sets in terms of prevalence, relationship to potential compensation, and emotional/functional status. In this prospective study, an unselected series of adults with uncomplicated MTBI (N = 139) was assessed at 6 months postinjury with a brief neuropsychological battery and measures of psychiatric symptoms/disorders, social support/community integration, health-related quality of life, and global outcome. In parallel analyses, participants with PCD/PCS were compared to those without the disorder. Potential compensation was an equally significant factor in both criteria sets. Persistent PCS criteria were met 3.1 times more frequently than persistent PCD criteria. Significant racial differences in fulfilling PCD/PCS criteria were found. No differences in emotional/functional status patterns or global outcome were found between the criteria sets except for minor dissimilarities in the social/community integration domain. The results demonstrate that despite large differences in the frequency of patients meeting the two diagnostic criteria sets, a clear basis for preferring either the PCD or PCS criteria remains to be determined.

Further Validation of the Expanded Auditory Verbal Learning Test for Detecting Poor Effort and Response Bias: Data from Temporal Lobectomy Candidates

The present study aimed to further examine the specificity of the Exaggeration Index of the expanded Auditory Verbal Learning Test procedure for detecting inadequate effort or response bias in a nonlitigating sample with unequivocal brain damage. Data from 56 patients with intractable epilepsy undergoing presurgical evaluation for temporal lobectomy were analyzed. In this sample, specificity was excellent at the recommended cut-off (94%), and comparable to that of another well-researched instrument for detecting inadequate effort, the Recognition Memory Test. Findings strongly support the generalizability of the specificity estimates obtained by Barrash et al. and, more broadly, the clinical utility of the Exaggeration Index. To facilitate diagnostic decision-making, the probability of invalid performances associated with each score on the Exaggeration Index, based on all clinical cross-validation samples reported to date, is also presented.

Recovery from mild traumatic brain injury

BACKGROUND

Fatigue is one of the most frequently reported symptoms after Mild Traumatic Brain Injury (MTBI). To date, systematic and comparative studies on fatigue after MTBI are scarce, and knowledge on causal mechanisms is lacking.

OBJECTIVES

To determine the severity of fatigue six months after MTBI and its relation to outcome. Furthermore, to test whether injury indices, such as Glasgow Coma Scale scores, are related to higher levels of fatigue.

METHODS

Postal questionnaires were sent to a consecutive group of patients with an MTBI and a minor-injury control group, aged 18-60, six months after injury. Fatigue severity was measured with the Checklist Individual Strength. Postconcussional symptoms and limitations in daily functioning were assessed using the Rivermead Post Concussion Questionnaire and the SF-36.

RESULTS

A total of 299 out of 618 eligible (response rate 52%) MTBI patients and 287 out of 482 eligible (response rate 60%) minor-injury patients returned the questionnaire. Ninety-five MTBI patients (32%) and 35 control patients (12%) were severely fatigued. Severe fatigue was highly associated with the experience of other symptoms, limitations in physical and social functioning, and fatigue related problems like reduced activity. Of various trauma severity indices, nausea and headache experienced on the ED were significantly related to higher levels of fatigue at six months.

CONCLUSIONS

In conclusion, one third of a large sample of MTBI patients experiences severe fatigue six months after injury, and this experience is associated with limitations in daily functioning. Our finding that acute symptoms and mechanism of injury rather than injury severity indices appear to be related to higher levels of fatigue warrants further investigation.

Evaluating the utility of ICD-10 diagnostic criteria for postconcussion syndrome following mild traumatic brain injury

The present study investigated the utility of the International Classification of Diseases and Related Health Problems, 10th edition (ICD-10) diagnostic criteria for postconcussion syndrome (PCS) symptoms by comparing symptom endorsement rates in a group of patients with mild traumatic brain injury (MTBI) to those of a noninjured control group at one month and three months post-injury. The 110 MTBI patients and 118 control participants were group-matched on age, gender, and education level. Seven of the nine self-reported ICD-10 PCS symptoms differentiated the groups at one month post-injury and two symptoms differentiated the groups at three months post-injury: symptom endorsement rates were higher in the MTBI group at both time periods. Fatiguing quickly and dizziness/vertigo best differentiated the groups at both time periods, while depression and anxiety/tension failed to differentiate the groups at either time period. Collectively, the ICD-10 PCS symptoms accurately classified the MTBI patients at one month post-injury, with the optimal positive test threshold of endorsement of five symptoms coinciding with a sensitivity and specificity of 73% and 61%, respectively. The ICD-10 PCS symptoms were unable to accurately classify the MTBI patients at three months post-injury.