Outcome from mild traumatic brain injury

Factors affecting mortality after traumatic brain injury in a resource-poor setting

Background

Traumatic brain injury (TBI) is a major cause of long‐term disability and economic loss to society. The aim of this study was to assess the factors affecting mortality after TBI in a resource‐poor setting.

Methods

Chart review was performed for randomly selected patients who presented with TBI between 2013 and 2017 at St Mary's Hospital, Lacor, northern Uganda. Data collected included demographic details, time from injury to presentation, and vital signs on arrival. In‐hospital management and mortality were recorded. Severe head injury was defined as a Glasgow Coma Scale score below 9.

Results

A total of 194 patient charts were reviewed. Median age at time of injury was 27 (i.q.r. 2–68) years. The majority of patients were male (M : F ratio 4·9 : 1). Some 30·9 per cent of patients had severe head injury, and an associated skull fracture was observed in 8·8 per cent. Treatment was mainly conservative in 94·8 per cent of patients; three patients (1·5 per cent) had burr‐holes, four (2·1 per cent) had a craniotomy, and three (1·5 per cent) had skull fracture elevation. The mortality rate was 33·0 per cent; 46 (72 per cent) of the 64 patients who died had severe head injury. Of the ten surgically treated patients, seven died, including all three patients who had a burr‐hole. In multivariable analysis, factors associated with mortality were mean arterial pressure (P = 0·012), referral status (P = 0·001), respiratory distress (P = 0·040), severe head injury (P = 0·011) and pupil reactivity (P = 0·011).

Conclusion

TBI in a resource‐poor setting remains a major challenge and affects mainly young males. Decisions concerning surgical intervention are compromised by the lack of both CT and intracranial pressure monitoring, with consequent poor outcomes.

Cutting to the Pathophysiology Chase: Translating Cutting-Edge Neuroscience to Rehabilitation Practice in Sports-Related Concussion Management

Mild traumatic brain injury, or concussion, is a common sports injury. Concussion involves physical injury to brain tissue and vascular and axonal damage that manifests as transient and often nonspecific clinical symptoms. Concussion diagnosis is challenging, and the relationship between brain injury and clinical symptoms is unclear. The purpose of this commentary was to translate cutting-edge neuroscience to rehabilitation practice. We (1) highlight potential biomarkers that may improve our understanding of concussion and its recovery, (2) explain why researchers must address the paucity of concussion research in female athletes, and (3) present female-specific factors that should be accounted for in future studies. Integrating objective, quantitative measures of concussion pathophysiology with concussion history, genetics, and genomics will help caregivers identify concussed athletes, tailor recovery protocols, and protect athletes from potential long-term effects of cumulative head impact. J Orthop Sports Phys Ther 2019;49(11):811-818. Epub 1 Jun 2019. doi:10.2519/jospt.2019.8884.

Semi-Automated Neurofeedback Therapy for Persistent Postconcussive Symptoms in a Military Clinical Setting: A Feasibility Study

Introduction

Neurofeedback therapy (NFT) has demonstrated effectiveness for reducing persistent symptoms following traumatic brain injury (TBI); however, its reliance on NFT experts for administration and high number of treatment sessions limits its use in military medicine. Here, we assess the feasibility of live Z-score training (LZT)—a variant of NFT that requires fewer treatment sessions and can be administered by nonexperts—for use in a military clinical setting.

Materials and Methods

A single group design feasibility study was conducted to assess acceptability, tolerance, treatment satisfaction, and change in symptoms after a 6-week LZT intervention in 38 Service Members (SMs) with persistent symptoms comorbid with or secondary to mild TBI. Acceptance and feasibility were assessed using treatment completion and patients’ satisfaction with treatment. To evaluate changes in symptom status, a battery of self-report questionnaires was administered at baseline, posttreatment, and 3-month follow-up to evaluate changes in psychological, neurobehavioral, sleep, pain, and headache symptoms, as well as self-efficacy in symptom management and life satisfaction.

Results

Participants tolerated the treatment well and reported a positive experience. Symptom improvement was observed, including depressive, neurobehavioral, and pain-related symptoms, with effects sustained at 3-month follow-up.

Conclusion

LZT treatment appears to be a feasible, non-pharmacological therapy amenable to SMs. Results from this pilot study promote further investigation of LZT as an intervention for SMs with persistent symptoms following TBI.

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.

Efficacy of Psychoeducation and Cognitive Rehabilitation After Mild Traumatic Brain Injury for Preventing Post-concussional Syndrome in Individuals With High Risk of Poor Prognosis: A Randomized Clinical Trial

Unfavorable outcomes (UO) occur in 15-20% of patients with mild traumatic brain injury (mTBI). Early identification of patients at risk of UO is crucial for suitable management to be initiated, increasing the chances of full recovery. We previously developed a prognostic tool for early identification (8-21 days after the injury) of patients likely to develop UO. Patients whose initial risk factors indicate UO are at risk of developing post-concussion syndrome (PCS). In the present study, we examined the beneficial effects of early multidimensional management (MM) on prognosis. We used our prognostic tool to classify 221 mTBI patients into a UO (97) group or a favorable outcome (FO) group (124). We randomized the UO patients into two subgroups: a group that underwent MM (involving psychoeducation and cognitive rehabilitation) (34) and a control group with no specific treatment other than psychoeducation (46). At 6 months, these two groups were compared to assess the impact of MM. Among the followed-up patients initially classified as having FO (101), 95% had FO at 6 months and only five had PCS [as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV classification]. Among the followed-up MM patients, 94% did not have PCS 6 months after injury, whereas 52% of the control patients had PCS. The effect of MM on the recovery of patients at 6 months, once adjusted for the main confounding factors, was significant (p < 0.001). These results show that the initiation of MM after early identification of at-risk mTBI patients can considerably improve their outcomes. Clinical Trials Registration: The study was registered at ClinicalTrials.gov (NCT03811626).

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.

Mild traumatic brain injury characteristics do not negatively influence cognitive processing therapy attendance or outcomes

Some providers have expressed hesitation about the appropriateness of PTSD treatment for veterans with a history of mild traumatic brain injury (mTBI), given concerns that TBI-related sequelae may negatively affect PTSD treatment and/or should be the focus of treatment instead. However, research suggests that those with a history of mTBI can benefit from evidence-based PTSD treatment. To extend these findings, we examined whether specific mTBI injury markers were associated with PTSD treatment attendance and response. Iraq/Afghanistan-era veterans with PTSD and history of mTBI (N = 88) all received Cognitive Processing Therapy (CPT; either standard CPT without the trauma account or SMART-CPT, a modified version of CPT that included cognitive rehabilitation strategies). Analyses examined whether time since injury, presence of loss of consciousness (LOC) or posttraumatic amnesia (PTA), and number and mechanism of mTBIs were associated with treatment attendance or response. None of the five injury variables examined were associated with number of treatment sessions attended. Multilevel modeling indicated that injury variables did not moderate treatment response (across treatment conditions) in terms of change in PTSD and depression symptoms. There was a three-way interaction showing that individuals who denied ever experiencing LOC exhibited a greater decrease in PTSD and depression symptoms in standard CPT relative to those in the SMART-CPT. Thus, a history of mTBI should not preclude individuals from receiving standard CPT, regardless of injury characteristics. In fact, PTSD treatment should often be a first line of treatment for these veterans, given evidence of a mental health etiology to persistent post-concussive symptoms.

Behavior, protein, and dendritic changes after model traumatic brain injury and treatment with nanocoffee particles

Background

Traumatic brain injury (TBI) is a widespread public health problem and a signature injury of our military in modern conflicts. Despite the long-term effects of even mild brain injuries, an effective treatment remains elusive. Coffee and several of its compounds, including caffeine, have been identified as having neuroprotective effects in studies of neurodegenerative disease. Given the molecular similarities between TBI and neurodegenerative disease, we have devised a study to test a nanocoffee extract in the treatment of a mouse model of mild TBI.

Results

After a single injury and two subsequent injections of nanocoffee, we identified treatment as being associated with improved behavioral outcomes, favorable molecular signaling changes, and dendritic changes suggestive of improved neuronal health.

Conclusions

We have identified coffee extracts as a potential viable multifaceted treatment approach to target the secondary injury associated with TBI.

Neuroradiological Changes Following Single or Repetitive Mild TBI

Objectives

To test the hypothesis that there are differences in neuroradiological measures between single and repeated mild traumatic brain injury using multimodal MRI.

Methods

A closed-head momentum exchange model was used to produce one or three mild head injuries in young adult male rats compared to non-injured, age and weight-matched controls. Six-seven weeks post-injury, rats were studied for deficits in cognitive and motor function. Seven-eight weeks post-injury changes in brain anatomy and function were evaluated through analysis of high resolution T2 weighted images, resting-state BOLD functional connectivity, and diffusion weighted imaging with quantitative anisotropy.

Results

Head injuries occurred without skull fracture or signs of intracranial bleeding or contusion. There were no significant differences in cognitive or motors behaviors between experimental groups. With a single mild hit, the affected areas were limited to the caudate/putamen and central amygdala. Rats hit three times showed altered diffusivity in white matter tracts, basal ganglia, central amygdala, brainstem, and cerebellum. Comparing three hits to one hit showed a similar pattern of change underscoring a dose effect of repeated head injury on the brainstem and cerebellum. Disruption of functional connectivity was pronounced with three mild hits. The midbrain dopamine system, hippocampus, and brainstem/cerebellum showed hypoconnectivity. Interestingly, rats exposed to one hit showed enhanced functional connectivity (or hyperconnectivity) across brain sites, particularly between the olfactory system and the cerebellum.

Interpretation

Neuroradiological evidence of altered brain structure and function, particularly in striatal and midbrain dopaminergic areas, persists long after mild repetitive head injury. These changes may serve as biomarkers of neurodegeneration and risk for dementia later in life.

Intracranial pressure elevations in diffuse axonal injury: association with nonhemorrhagic MR lesions in central mesencephalic structures

OBJECTIVE

Increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in patients with DAI.

METHODS

Fifty-two patients with severe TBI (median age 24 years, range 9-61 years), who had undergone ICP monitoring and had DAI on MRI, as determined using T2*-weighted gradient echo, susceptibility-weighted imaging, and diffusion-weighted imaging (DWI) sequences, were enrolled. The proportion of good monitoring time (GMT) with ICP > 20 mm Hg during the first 120 hours postinjury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression.

RESULTS

All patients had episodes of ICP > 20 mm Hg. The mean proportion of GMT with ICP > 20 mm Hg was 5%, and 27% of the patients (14/52) spent more than 5% of GMT with ICP > 20 mm Hg. The Glasgow Coma Scale motor score at admission (p = 0.04) and lesions on DWI sequences in the substantia nigra and mesencephalic tegmentum (SN-T, p = 0.001) were associated with the proportion of GMT with ICP > 20 mm Hg. In multivariable linear regression, lesions on DWI sequences in SN-T (8% of GMT with ICP > 20 mm Hg, 95% CI 3%-13%, p = 0.004) and young age (-0.2% of GMT with ICP > 20 mm Hg, 95% CI -0.07% to -0.3%, p = 0.002) were associated with increased ICP.

CONCLUSIONS

Increased ICP occurs in approximately one-third of patients with severe TBI who have DAI. Age and lesions on DWI sequences in the central mesencephalon (i.e., SN-T) are associated with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in patients with DAI.

The effect of mild traumatic brain injury on the visual processing of global form and motion

Cortical visual processing involves the ventral stream (form perception) and the dorsal stream (motion perception). We assessed whether mild traumatic brain injury (TBI) differentially affects these two streams. Eleven adults with mild TBI (28 ± 9 yrs, 17 ± 5 months post injury) and 25 controls (25 ± 5 yrs) participated. Participants completed tests of global processing involving Glass patterns (form) and random dot kinematograms (motion), measurement of contrast thresholds for motion direction discrimination, a comprehensive vision screening and the Post-Concussion Symptom Inventory (PCSI). Our results showed that the mild TBI group had significantly higher (worse) global form (mean ± SD: TBI 25 ± 6%, control 21 ± 5%) and motion (TBI 14 ± 7%, control 11 ± 3%) coherence thresholds than controls. The magnitude of the mild TBI group deficit did not differ between the two tasks. Contrast thresholds for motion direction discrimination did not differ between the groups, but were positively correlated with PCSI score (r² = 0.51. p = 0.01) in the mild TBI group. The mild TBI group had worse outcomes than controls for all clinical measurements of vision except distance visual acuity. In conclusion, mild TBI affects processing in both the dorsal and ventral cortical processing streams equally. In addition, spatiotemporal contrast sensitivity may be related to the symptoms of mild TBI.

Reaction time and cognitive-linguistic performance in adults with mild traumatic brain injury

Objective: The purpose of this study was to characterize cognitive-linguistic performance in adults with mild traumatic brain injury (mTBI) to advance assessment and treatment practices. We hypothesized that individuals with mTBI would demonstrate longer reaction times (RTs) and greater error rates when compared to an orthopedic injury (OI) group on a category-naming task. Method: Participants were age and education-matched adults with mTBI (n = 20; 12 females) and adults with OI (n = 21; 5 females) who were discharged to home after an Emergency Department visit. Our primary task was a category-naming task shown to be sensitive to language deficits after mTBI. The task was adapted and administered under speeded and unspeeded conditions. Results: There was a significant main effect of condition on RT (speeded faster than unspeeded) and accuracy (more errors in the speeded condition). There was a marginally significant effect of group on errors, with more errors in the mTBI group than the OI group. Naming RT and accuracy in both conditions were moderately correlated with injury variables and symptom burden. Conclusions: Our data showed a marginal effect of group on accuracy of performance. Correlations found between naming and neurobehavioural symptoms, including sleep quality, suggest that the latter should be considered in future research.

Concussion: A Global Perspective

Concussion, also referred to as mild traumatic brain injury (MTBI), is a common pediatric condition. This article reviews global perspectives on the epidemiology, treatment, and prognosis of concussion in children. A Pubmed search was conducted using Clinical Queries with the key terms "concussion" and "mild traumatic brain injury," and the search was limited to "children." The search strategy included meta-analyses, randomized controlled trials, clinical trials, and reviews. The majority of publications were from Canada and the United States. Prevalence estimates vary widely according to case definition and studied population. Due to under-reporting and to the widely varying definitions of concussion, it is difficult to estimate how common the condition is. Common causes of concussions include sports injuries, motor vehicle collisions, bicycle accidents, falls, and assaults. Diagnosis is mainly clinical. Because concussion results from a disturbance in brain function rather than structural injury, neuroimaging studies, such as computed tomography and magnetic resonance imaging, are not routinely recommended. Treatment generally involves physical and cognitive rest, with a gradual return to activities, whereas prolonged rest may actually worsen outcomes. Helmets when bicycling, skiing, snowboarding, motor biking, placing age limits on certain types of contact sports, and encouragement of fair play are recommended to decrease the impact of head injuries but they do not prevent concussions. Overall outcomes are generally favorable. The symptoms and signs of concussion usually resolve within 10 days; most patients recover in 48-72 hours. Global perspectives on management and prognosis are lacking. Concussions or MTBIs are common childhood injuries and the prognosis is good but information is predominantly from Canada and the USA. Research in other countries in particular low and middle income countries is vital to have a global perspective on MTBI.

Network Analysis and Precision Rehabilitation for the Post-concussion Syndrome

Some people experience persistent symptoms following a mild traumatic brain injury (MTBI), and the etiology of those symptoms has been debated for generations. Post-concussion-like symptoms are caused by many factors both before and after MTBI, and this non-specificity is the bedrock of the conundrum regarding the existence of the post-concussion syndrome. A latent model or common cause theory for the syndrome is inconsistent with the prevailing biopsychosocial conceptualization. It is the thesis of this paper that adopting a network perspective for persistent symptoms following MTBI, including the post-concussion syndrome, could lead to new insights and targeted treatment and rehabilitation strategies. The network perspective posits that symptoms co-occur because they are strongly inter-related, activating, amplifying, and mutually reinforcing, not because they arise from a common latent disease entity. This approach requires a conceptual shift away from thinking that symptoms reflect an underlying disease or disorder toward viewing inter-related symptoms as constituting the syndrome or disorder. The symptoms do not arise from an underlying syndrome—the symptoms are the syndrome. A network analysis approach allows us to embrace heterogeneity and comorbidity, and it might lead to the identification of new approaches to sequenced care. The promise of precision rehabilitation requires us to better understand the interconnections among symptoms and problems so that we can produce more individualized and effective treatment and rehabilitation.

Mammalian Models of Traumatic Brain Injury and a Place for Drosophila in TBI Research

Traumatic brain injury (TBI), caused by a sudden blow or jolt to the brain that disrupts normal function, is an emerging health epidemic with ∼2.5 million cases occurring annually in the United States that are severe enough to cause hospitalization or death. Most common causes of TBI include contact sports, vehicle crashes and domestic violence or war injuries. Injury to the central nervous system is one of the most consistent candidates for initiating the molecular and cellular cascades that result in Alzheimer's disease (AD), Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS). Not every TBI event is alike with effects varying from person to person. The majority of people recover from mild TBI within a short period of time, but repeated incidents can have deleterious long-lasting effects which depend on factors such as the number of TBIs sustained, time till medical attention, age, gender and genetics of the individual. Despite extensive research, many questions still remain regarding diagnosis, treatment, and prevention of long-term effects from TBI as well as recovery of brain function. In this review, we present an overview of TBI pathology, discuss mammalian models for TBI and focus on current methods using Drosophila melanogaster as a model for TBI study. The relatively small brain size (∼100,000 neurons and glia), conserved neurotransmitter signaling mechanisms and sophisticated genetics of Drosophila allows for cell biological, molecular and genetic analyses that are impractical in mammalian models of TBI.

Premorbid risk factors influencing labour market attachment after mild traumatic brain injury: a national register study with long-term follow-up

OBJECTIVES

Some patients with mild traumatic brain injury (mTBI) experience persistent postconcussive symptoms, influencing the ability to work. This study assessed associations between mTBI and labour market attachment (up to 5 years postinjury) in patients with different premorbid characteristics.

DESIGN AND SETTING

Danish national cohort study with 5-year register follow-up.

PARTICIPANTS

We included hospital admitted patients between 18 and 60 years diagnosed with mTBI (International Classification of Diseases, version 10 diagnosis S06.0) (n=19 732). For each patient, one control was selected matched on age, gender and municipality (n=18 640).

PRIMARY OUTCOME MEASURE

Primary outcome was 'not attending ordinary work', and premorbid risk factors were cohabitation status, education, ethnicity, gender, age and comorbidities.

RESULTS

The odds of not attending ordinary work increased from 6 months to 5 years. The highest increased odds (approximately twice as high for patients) of not attending ordinary work at 5 years were found in the highest educational group (OR 2.15, 95% CI 1.78 to 2.59), for patients of non-Danish origin (OR 1.98, 95% CI 1.52 to 2.57), for patients between 30 and 39 years (OR 1.93, 95% CI 1.68 to 1.23) and for patients with somatic comorbidities (OR 1.81, 95% CI 1.38 to 2.37). Contrary to expectations, we did not find higher odds in patients with psychiatric diagnoses (OR 1.12, 95% CI 0.76 to 1.60).

CONCLUSIONS

Important premorbid characteristics for lower labour market participation after mTBI were higher education, non-Danish origin, age 30-39 years and having somatic comorbidities. Demographic and health-related variables should be considered when assessing patients with mTBI at risk of long-term sickness absence.

TRIAL REGISTRATION NUMBER

NCT03214432; Results.

Functional Outcome and Mental Health Symptoms in Military Personnel and Veterans Pursuing Postsecondary Education After Traumatic Brain Injury: A VA TBI Model Systems Study

Background

TBI is a leading cause of disability among veterans and active duty military personnel, and presents an obstacle to community reintegration. Prior studies examining adult survivors of TBI pursuing postsecondary education have methodological flaws that limit the understanding the scope and severity of sequelae experienced by persons with TBI who attend college.

Objective

To describe (a) physical and cognitive functioning, and (b) postconcussion and mental health symptoms in veterans and military personnel (V/M) with traumatic brain injury (TBI) enrolled in postsecondary education programs after discharge from rehabilitation.

Method

Cross-sectional study. Participants were recruited from five Veterans Affairs (VA) Polytrauma Rehabilitation Centers, enrolled in the VA TBI Model Systems parent study, and attending school during follow-up (N= 155). Outcome measures included the Functional Independence Measure (FIM), Neurobehavioral Symptom Inventory (NSI), Post-traumatic Stress Disorder (PTSD) Checklist-Civilian version (PCL-C), Patient Health Questionnaire-Depression (PHQ-9), and Generalized Anxiety Disorder Questionnaire (GAD-7).

Findings

Participants were mostly male (92.9%) and White (81.4%), with mild (40.0%), moderate (11.5%), severe (34.5%), or very severe TBI (23.0%). Depression, anxiety, PTSD, and postconcussion symptoms were lowest in participants with very severe TBI and highest in those with mild TBI. There were no significant differences in FIM across TBI severity levels.

Conclusion

This study supports the need for rehabilitation counselors, educators, and administrators to prepare future practitioners to deliver tailored services to student V/M with TBI. These services can facilitate successful community reintegration and transition into civilian school settings. Symptom profiling may inform personalized cognitive interventions to enhance these students’ academic success.

Vocational Rehabilitation in Mild Traumatic Brain Injury: Supporting Return to Work and Daily Life Functioning

Persisting post-concussive symptoms are challenging to treat and may delay return-to-work (RTW). The aims of this study were to describe a multidisciplinary and holistic vocational rehabilitation (VR) program for individuals with mild traumatic brain injury (mTBI) and to explore course and predictors of employment outcome during VR. The VR program was described using the Standard Operating Procedures (SOPs) framework. Further, a retrospective, cohort study on individuals with mTBI receiving VR was conducted based on clinical records (n = 32; 22% males; mean age 43.2 years; 1.2 years since injury on average). The primary outcome was difference in hours at work per week from pre- to post-VR, and the secondary outcome was change in a three-level RTW-status. Time since injury, age, sex, and loss of consciousness were investigated as predictors of the outcomes. The VR intervention is individually tailored and targets patients' individual needs. Thus, it may combine a variety of methods based on a biopsychosocial theoretical model. During VR, hours at work, 17.0 ± 2.2, p < 0.001, and RTW-status, OR = 14.0, p < 0.001, improved significantly with 97% having returned to work after VR. Shorter length of time since injury and male sex were identified as predictors of a greater gain of working hours. Time since injury was the strongest predictor; double the time was associated with a reduction in effect by 4.2 ± 1.4 h after adjusting for working hours at start of VR. In sum, these results suggest that individuals facing persistent problems following mTBI may still improve employment outcomes and RTW after receiving this multidisciplinary and holistic VR intervention, even years after injury. While results are preliminary and subject to bias due to the lack of a control group, this study warrants further research into employment outcomes and VR following mTBI, including who may benefit the most from treatment.

Injury Severity and Depressive Symptoms in a Post-acute Brain Injury Rehabilitation Sample

This study explored the relationship between injury severity and depressive symptoms for treatment-seeking individuals with traumatic brain injury (TBI). The Mayo Classification System was used to classify TBI severity in 72 participants who completed the Patient Health Questionnaire at admission and at dismissal from rehabilitation. Patients with mild TBI reported more depressive symptoms than those with moderate or severe TBI at admission and at dismissal. Although injury severity groups differed by gender composition, gender had no effect on severity of depressive symptoms. All participants reported fewer depressive symptoms at dismissal from rehabilitation, including lower endorsement of dysphoria by discharge. Participants with mild TBI, however, continued to report depressive symptoms of a mild severity at dismissal, with residual problems with anhedonia. These findings underscore the benefit of interdisciplinary post-acute rehabilitation services for persons with TBI of any severity, including those with mild injury.

The long-term consequences of repetitive head impacts: Chronic traumatic encephalopathy

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to repetitive head impacts (RHI). Although described in boxers for almost a century, scientific and public interest in CTE grew tremendously following a report of postmortem evidence of CTE in the first former professional American football player in 2005. Neuropathologic diagnostic criteria for CTE have been defined, with abnormal perivascular deposition of hyperphosphorylated tau at the sulcal depths as the pathognomonic feature. CTE can currently only be diagnosed postmortem, but clinical research criteria for the in vivo diagnosis of CTE have been proposed. The clinical phenotype of CTE is still ill-defined and there are currently no validated biomarkers to support an in-life diagnosis of "Probable CTE." Many knowledge gaps remain regarding the neuropathologic and clinical make-up of CTE. An increased understanding of CTE is critical given the millions that could potentially be impacted by this disease. This chapter describes the state of the literature on CTE. The historical origins of CTE are first presented, followed by a comprehensive description of the neuropathologic and clinical features. The chapter concludes with discussion on future research directions, emphasizing the importance of diagnosing CTE during life to facilitate development of preventative and intervention strategies.

An experimental study of the effect on activity intentions of postconcussion recovery advice

This study tested the effect of issuing return-to-activity advice on activity intentions at Day 2 and Day 10 days post simulated mild traumatic brain injury. One hundred and twenty-eight volunteers were randomly allocated to one of two groups who received ( n =  65) or did not receive standardized post-injury advice ( n =  63). To prime the simulation, the participants read a mild traumatic brain injury vignette about a person who is concussed while playing sport. Then the participants role-played the injured person and reported activity intentions for three activity types (cognitive, physical and restful) twice, once for each time frame (i.e. Day 2 and Day 10). The advice was to rest for the first 24–48 h and then gradually resume normal activities. There was no significant group by activity-type interaction ( p > .05) at Day 2. When both time frames were considered, there was no significant group × time frame interaction for any activity type or any item, except for an increase in non-manual (clerical) work and weight training at Day 10 compared to Day 2 in the group with the advice. In general, the intentions for all activity types were consistent with the recovery advice (i.e., rest then increasing activity), even when the advice was not given. However, at Day 10, cognitive and physical activity levels were still expected to be lower than usual (pre-injury), and many participants were uncertain about the concept of cognitive rest. These factors, along with individual patient circumstances, should be taken into account in rehabilitation planning.

Associations between coping style, illness perceptions and self-reported symptoms after mild traumatic brain injury in prospectively studied pre-morbidly healthy individuals

This study investigated whether coping style and/or illness perceptions are related to the severity of self-reported post-concussion syndrome (PCS) symptoms in the post-acute period after mild traumatic brain injury (mTBI). We hypothesised that reporting of early and late enduring-type PCS symptomatology (self-reported symptoms) would be significantly and negatively associated with: (a) an active "approach" coping style and (b) the belief that the injury would have negative consequences on the respondent's life. Using a prospective observational design we assessed 61 pre-morbidly healthy individuals who were admitted to hospital after an mTBI. Participants were assessed with measures of coping style and illness perception as well as PCS, depressive, anxiety and post-traumatic stress symptomatology. After controlling for current psychological distress, approach coping style significantly and independently predicted the severity of self-reported symptoms for early-type PCS symptomatology, but not late enduring-type PCS symptoms. The extent to which the respondent believed their symptoms were due to the mTBI significantly and independently predicted both early and late enduring-type PCS symptoms. This study indicates that different patterns of coping and illness perceptions are associated with early vs. late enduring types of PCS symptoms; this may have implications for the treatment of post-injury self-reported symptoms.

Design of an early intervention for persistent post-concussion symptoms in adolescents and young adults: A feasibility study

BACKGROUND

About 5-15 % of patients with concussion experience persistent post-concussion symptoms (PCS) longer than 3 months post-injury.

OBJECTIVE

To explore the feasibility of a new intervention for young patients with persistent PCS and long-term changes after intervention.

METHODS

Thirty-two consecutive patients (15-30 years) with persistent PCS 2-4 months post-injury were recruited from a cohort study or referred to a non-randomized feasibility study of an individually tailored, 8-week, multidisciplinary intervention. Assessment was performed at baseline, end of intervention (EOI), and at 3- and 12-month follow-up (FU). Main measures were The Experience of Service Questionnaire (ESQ), Rivermead Post-Concussion Symptoms Questionnaire (RPQ) and The Quality of Life after Brain Injury - Overall Scale (QOLIBRI-OS).

RESULTS

Twenty-three (72%) patients completed the intervention. The ESQ demonstrated high patient satisfaction. There was a decrease of PCS and an increase in quality of life from baseline to EOI: RPQ score -8.9 points, 95% CI 4.5 to 13.3, p < 0.001; QOLIBRI-OS score +10.5 points, 95% CI 2.5 to 18.5, p = 0.010. Improvement was maintained at 3- and 12-month FU.

CONCLUSION

The new early intervention is feasible and may prevent chronification of PCS. An RCT is currently performed to evaluate the effect of the intervention.

Service and support needs following pediatric brain injury: perspectives of children with mild traumatic brain injury and their parents

OBJECTIVE

To provide a qualitative examination of the service and support needs of children who have had a mild traumatic brain injury (mTBI), and their parents, in order to improve clinical services.

METHODS

Semi-structured interviews were conducted with 9 children (8-12 years; M = 10.6 years, SD = 0.8) and their parents (n = 9) 29-55 days (M = 34 days; SD = 9.3) after presenting to an Australian Paediatric Emergency Department (PED) for mTBI. Children's post-concussive symptoms (PCS) were additionally measured using the Post-Concussive Symptom Inventory (PCSI). Audio recordings were transcribed, and a thematic analysis was conducted.

RESULTS

Post-injury needs were reflected in four main themes: Communication; Family Burden; Continuity of Care; and Social and Community Support. These themes reflected children's and parents' needs for information, emotional/social/community support, and follow-up care. Both the children's and parents' needs, and the extent to which they were met, appeared to be related to the severity and duration of the child's PCS.

CONCLUSIONS

Dedicated pediatric mTBI follow-up services that build on family's resources and meet their individual needs for information, emotional support, and referral may assist in optimizing post-injury outcomes.

Investigating the validity and reliability of Electrovestibulography (EVestG) for detecting post-concussion syndrome (PCS) with and without comorbid depression

Features from Electrovestibulography (EVestG) recordings have been used to classify and measure the severity of both persistent post-concussion syndrome (PCS) and major depressive disorder. Herein, we examined the effect of comorbid depression on the detection of persistent PCS using EVestG. To validate our previously developed EVestG classifier for PCS detection, the classifier was tested with a new blind dataset (N = 21). The unbiased accuracy for identifying the new PCS from controls was found to be >90%. Next, the PCS group (N = 59) was divided into three subgroups: PCS with no-depression (n = 18), PCS with mild-depression (n = 27) and PCS with moderate/severe-depression (n = 14). When moderate/severe depression was present, PCS classification accuracy dropped to 83%. By adding an EVestG depression feature from a previous study, separation accuracy of each PCS subgroup from controls was >90%. A four and three-group (excluding mild-depression subgroup) classification, achieved an accuracy of 74% and 81%, respectively. Correlation analysis indicated a significant correlation (R = 0.67) between the depression feature and the MADRS depression score as well as between the PCS-specific feature and Rivermead Post-Concussion Questionnaire (RPQ) (R = −0.48). No significant correlation was found between the PCS-specific feature and the MADRS score (R = 0.20) or between RPQ and the depression feature (R = 0.12). The (PCS-specific and depression-specific) EVestG features used herein have the potential to robustly detect and monitor changes, relatively independently, in both persistent PCS and its depression comorbidity. Clinically, this can be particularly advantageous.

Central nervous system microbleeds in the acute phase are associated with structural integrity by DTI one year after mild traumatic brain injury: A longitudinal study

INTRODUCTION

Several imaging modalities are under investigation to unravel the pathophysiological mystery of delayed performance deficits in patients after mild traumatic brain injury (mTBI). Although both imaging and neuropsychological studies have been conducted, only few data on longitudinal correlations of diffusion tensor imaging (DTI), susceptibility weighted imaging (SWI) and extensive neuropsychological testing exist.

METHODS

MRI with T1- and T2-weighted, SWI and DTI sequences at baseline and 12 months of 30 mTBI patients were compared with 20 healthy controls. Multiparametric assessment included neuropsychological testing of cognitive performance and post-concussion syndrome (PCS) at baseline, 3 and 12 months post-injury. Data analysis encompassed assessment of cerebral microbleeds (Mb) in SWI, tract-based spatial statistics (TBSS) and voxel-based morphometry (VBM) of DTI (VBM-DTI). Imaging markers were correlated with neuropsychological testing to evaluate sensitivity to cognitive performance and post-concussive symptoms.

RESULTS

Patients with Mb in SWI in the acute phase showed worse performance in several cognitive tests at baseline and in the follow-ups during the chronic phase and higher symptom severity in the post concussion symptom scale (PCSS) at twelve months post-injury. In the acute phase there was no statistical difference in structural integrity as measured with DTI between mTBI patients and healthy controls. At twelve months post-injury, loss of structural integrity in mTBI patients was found in nearly all DTI indices compared to healthy controls.

CONCLUSIONS

Presence of Mb detected by SWI was associated with worse cognitive outcome and persistent PCS in mTBI patients, while DTI did not prove to predict neuropsychological outcome in the acute phase.

NIH toolbox cognition tests following traumatic brain injury: Frequency of low scores

PURPOSE/OBJECTIVE

To apply multivariate base rate analyses to the National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) to facilitate the identification of cognitive impairment in individuals with traumatic brain injury (TBI). Research Method/Design: In a multisite cross-sectional design, 158 participants who sustained a complicated mild or moderate TBI (n = 74) or severe TBI (n = 84) at least 1 year earlier were administered the NIHTB-CB. The NIHTB-CB is comprised of 2 crystallized cognition tests (reflecting premorbid ability) and 5 fluid cognition tests, measuring processing speed, memory, and executive functioning. Base rates for obtaining 0 to 5 low fluid cognition scores were calculated across a range of cutoffs for defining a low test score (≤25th to 5th percentiles). Base rates of low scores in the TBI sample were compared to the NIHTB-CB normative sample using diagnostic accuracy statistics.

RESULTS

The proportion of the TBI sample obtaining low scores decreased as the cutoff for defining a low score decreased. Individuals with lower premorbid cognitive ability, as measured by NIHTB-CB Crystallized Composite score, tended to produce more low scores on the NIHTB-CB fluid cognition tests, even when using fully demographically adjusted scores. Certain patterns of low scores were associated with TBI (defined as likelihood ratio >2.0), whereas others were nonspecific, occurring almost as often in participants without TBI.

CONCLUSIONS/IMPLICATIONS

Premorbid ability stratified base rate tables provided in this article can guide researchers and clinicians in the interpretation of NIHTB-CB performance in adults with TBI. (PsycINFO Database Record

The Microtubule-Modulating Drug Epothilone D Alters Dendritic Spine Morphology in a Mouse Model of Mild Traumatic Brain Injury

Microtubule dynamics underpin a plethora of roles involved in the intricate development, structure, function, and maintenance of the central nervous system. Within the injured brain, microtubules are vulnerable to misalignment and dissolution in neurons and have been implicated in injury-induced glial responses and adaptive neuroplasticity in the aftermath of injury. Unfortunately, there is a current lack of therapeutic options for treating traumatic brain injury (TBI). Thus, using a clinically relevant model of mild TBI, lateral fluid percussion injury (FPI) in adult male Thy1-YFPH mice, we investigated the potential therapeutic effects of the brain-penetrant microtubule-stabilizing agent, epothilone D. At 7 days following a single mild lateral FPI the ipsilateral hemisphere was characterized by mild astroglial activation and a stereotypical and widespread pattern of axonal damage in the internal and external capsule white matter tracts. These alterations occurred in the absence of other overt signs of trauma: there were no alterations in cortical thickness or in the number of cortical projection neurons, axons or dendrites expressing YFP. Interestingly, a single low dose of epothilone D administered immediately following FPI (and sham-operation) caused significant alterations in the dendritic spines of layer 5 cortical projection neurons, while the astroglial response and axonal pathology were unaffected. Specifically, spine length was significantly decreased, whereas the density of mushroom spines was significantly increased following epothilone D treatment. Together, these findings have implications for the use of microtubule stabilizing agents in manipulating injury-induced synaptic plasticity and indicate that further study into the viability of microtubule stabilization as a therapeutic strategy in combating TBI is warranted.

Sensory Sensitivity in TBI: Implications for Chronic Disability

PURPOSE OF REVIEW

This review investigates the relationship between sensory sensitivity and traumatic brain injury (TBI), and the role sensory sensitivity plays in chronic disability.

RECENT FINDINGS

TBI is a significant cause of disability with a range of physical, cognitive, and mental health consequences. Sensory sensitivities (e.g., noise and light) are among the most frequently reported, yet least outwardly recognizable symptoms following TBI. Clinicians and scientists alike have yet to identify consistent nomenclature for defining noise and light sensitivity, making it difficult to accurately and reliably assess their influence. Noise and light sensitivity can profoundly affect critical aspects of independent function including communication, productivity, socialization, cognition, sleep, and mental health. Research examining the prevalence of sensory sensitivity and evidence for the association of sensory sensitivity with TBI is inconclusive. Evidence-based interventions for sensory sensitivity, particularly following TBI, are lacking.

Longitudinal Changes of Caudate-Based Resting State Functional Connectivity in Mild Traumatic Brain Injury

Mild traumatic brain injury (mild TBI) is associated with dysfunctional brain network and accumulating evidence is pointing to the caudate as a vulnerable hub region. However, little is known about the longitudinal changes in the caudate-based resting-state functional connectivity following mild TBI. In the current study, 50 patients with mild TBI received resting-state functional magnetic resonance imaging as well as neuropsychological assessments within 7 days post-injury (acute phase) and 1 month later (subacute phase). Thirty-six age- and gender- matched healthy controls underwent the same protocol. The caudate was segmented into the dorsal and ventral sub-regions based on their related functionally distinct neural circuits and separate functional connectivity was investigated. Results indicated that patients with mild TBI at acute phase exhibited reduced left dorsal caudate-based functional connectivity with ventral lateral prefrontal cortex, dorsal anterior cingulate cortex, and inferior parietal lobule, which mainly distributed in the cognitive control network, and reduced right ventral caudate-based functional connectivity with the dorsal lateral prefrontal cortex, dorsal anterior cingulate cortex (dACC), and bilateral ventral anterior cingulate cortex (vACC), which mainly distributed in the executive network and emotional processing network. Furthermore, patients with mild TBI presented the reduced functional connectivity between the left dorsal caudate and the ventral lateral prefrontal cortex (vlPFC) compared with healthy controls at acute phase while this difference became no significance and return to the normal level following 1 month post-injury subacute phase. Similarly, the functional connectivity between the right ventral caudate and anterior cingulate cortex (both dorsal and ventral part) showed the reduced strength in patients compared with healthy controls only at the acute phase but presented no significant difference at subacute phase following mild TBI. Along the same line, patients with mild TBI presented the impaired performance on the information processing speed and more complaints on the pain impact index at acute phase compared with healthy controls but showed no significant difference at the follow-up 1 month post-injury subacute phase. The longitudinal changes of caudate-based dysfunction connectivity could serve as a neuroimaging biomarker following patients with mild TBI, with the evidence that the abnormal caudate-based functional connectivity at acute phase have returned to the normal level accompanying with the recovery of the neuropsychological syndromes following patients with mild TBI at subacute phase.

Repeated Mild Traumatic Brain Injury: Potential Mechanisms of Damage

Mild traumatic brain injury (mTBI) represents a significant public healthcare concern, accounting for the majority of all head injuries. While symptoms are generally transient, some patients go on to experience long-term cognitive impairments and additional mild impacts can result in exacerbated and persisting negative outcomes. To date, studies using a range of experimental models have reported chronic behavioral deficits in the presence of axonal injury and inflammation following repeated mTBI; assessments of oxidative stress and myelin pathology have thus far been limited. However, some models employed induced acute focal damage more suggestive of moderate–severe brain injury and are therefore not relevant to repeated mTBI. Given that the nature of mechanical loading in TBI is implicated in downstream pathophysiological changes, the mechanisms of damage and chronic consequences of single and repeated closed-head mTBI remain to be fully elucidated. This review covers literature on potential mechanisms of damage following repeated mTBI, integrating known mechanisms of pathology underlying moderate–severe TBIs, with recent studies on adult rodent models relevant to direct impact injuries rather than blast-induced damage. Pathology associated with excitotoxicity and cerebral blood flow-metabolism uncoupling, oxidative stress, cell death, blood-brain barrier dysfunction, astrocyte reactivity, microglial activation, diffuse axonal injury, and dysmyelination is discussed, followed by a summary of functional deficits and preclinical assessments of therapeutic strategies. Comprehensive characterization of the pathology underlying delayed and persisting deficits following repeated mTBI is likely to facilitate further development of therapeutic strategies to limit long-term sequelae.

MLC901 (NeuroAiD II™) for cognition after traumatic brain injury: a pilot randomized clinical trial

Background and purpose

Treatments to facilitate recovery after traumatic brain injury (TBI) are urgently needed. We conducted a 9‐month pilot, randomized placebo‐controlled clinical trial to examine the safety and potential effects of the herbal supplement MLC901 (NeuroAiD II™) on cognitive functioning following TBI.

Methods

Adults aged 18–65 years at 1–12 months after mild or moderate TBI were randomized to receive MLC901 (0.8 g capsules 3 times daily) or placebo for 6 months. The primary outcome was cognitive functioning as assessed by the CNS Vital Signs online neuropsychological test. Secondary outcomes included the Cognitive Failures Questionnaire, the Rivermead Post‐concussion Symptom Questionnaire (neurobehavioral sequelae), Quality of Life after Brain Injury, Hospital Anxiety and Depression Scale, Modified Fatigue Impact Scale and extended Glasgow Outcome Scale (physical disability). Assessments were completed at baseline and at 3‐, 6‐ and 9‐month follow‐up. Linear mixed‐effects models were conducted, with the primary outcome time‐point of 6 months.

Results

A total of 78 participants [mean age 37.5 ± 14.8 years, 39 (50%) female] were included in the analysis. Baseline variables were similar between groups (treatment group, n = 36; control group, n = 42). Linear mixed‐effects models controlling for time, group allocation, repeated measurements, adherence and baseline assessment scores revealed significant improvements in complex attention (P = 0.04, d = 0.6) and executive functioning (P = 0.04, d = 0.4) at 6 months in the MLC901 group compared with controls. There were no significant differences between the groups for neurobehavioral sequelae, mood, fatigue, physical disability or overall quality of life at 6 months. No serious adverse events were reported.

Conclusions

MLC901 was safe and well tolerated post‐TBI. This study provided Class I/II evidence that, for patients with mild to moderate TBI, 6 months of MLC901 improved cognitive functioning.

Minute Pulsed Electromagnetic Neurostimulation for Mixed Trauma Syndromes

Research regarding noninvasive brain stimulation technologies for the treatment of mild traumatic brain injury (mTBI), posttraumatic stress disorder (PTSD), and mixed (mTBI/PTSD) trauma syndromes has been increasing exponentially. Technologies with the greatest potential thus far include repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), and cranial electrotherapy stimulation (CES). The nature and some of the controversies distinguishing mTBI, PTSD, and mTBI/PTSD are reviewed along with evidence for shared underlying mechanisms. An overview of treatment applications for rTMS, tDCS, and CES are also reviewed. A novel variant of a minute pulsed electromagnetic stimulation technology linked to ongoing electroencephalograph monitoring known as the Flexyx Neurotherapy System is introduced with an overview of the technology and technique, as well as a summary of supportive data to date that explores potential applications for amelioration of these syndromes.

Exploring concussion awareness in hockey with a First Nations community in Canada

OBJECTIVE

The purpose of this pilot study was twofold: (1) to begin to understand concussion in youth hockey in a First Nations community in Canada and (2) to determine the impact of a novel concussion education workshop.

DESIGN

A one-group quasiexperimental time series study was undertaken.

SAMPLE

A total of 41 participants consented, with 71% (n = 29) completing data collection at all three study time points.

MEASUREMENT AND INTERVENTIONS

Two nurses one from the First Nations community and one from the tertiary care center collaborated to develop and deliver the intervention on concussion specifically general, hockey and symptom knowledge. The primary outcome was Total Knowledge Score (TKS), whereby correct responses to a self-reported questionnaire were summed and then converted to a percentage.

RESULTS

The TKS were similar across study time points; preworkshop 71.7%, postworkshop 71.8%, and 6-month follow-up 72%.

CONCLUSIONS

Nurses worked collaboratively with cultural experts from a First Nations community to integrate Indigenous ways of knowing into concussion awareness and safety for First Nations youth playing hockey.

Long-term effects of mild traumatic brain injuries to oculomotor tracking performances and reaction times to simple environmental stimuli

Understanding the long-term effects of concussive events remains a challenge for the development of modern medical practices and the prevention of recurrent traumas. In this study, we utilized indices of oculomotor performance and the ability to react to simple environmental stimuli to assess the long-term motor effects of traumatic brain injury in its mildest form (mTBI). We performed analysis of eye movement accuracy, investigated the presence of abnormal eye movements, and quantified time to react to simple environmental stimuli on long-term mTBI survivors. Results indicated the presence of impairments to basic neural functions used to explore and respond to environmental demands long after the occurrence of mTBIs. Specifically, the result revealed the presence of abnormal saccadic eye movements while performing horizontal smooth pursuit, diminished accuracy of primary saccadic horizontal eye movement, and a widespread slower reaction to both visual and auditory stimuli. The methodology used in this study indicated to be potentially useful in aiding future investigations of neural circuitry impaired by mTBI and provide indices of recovery in future clinical trials testing mTBI-related clinical interventions.

Traumatic Brain Injury, Sleep, and Mental Health: A Longitudinal Study of Air Force Personnel Pre- and Postdeployment to Iraq

OBJECTIVE

We investigated the complex relationships between traumatic brain injury (TBI), sleep, and mental health problems longitudinally among US service members (SMs) pre- and postdeployment to Iraq.

PARTICIPANTS

One hundred sixty-eight SMs enrolled in a 4-week Air Force Basic Combat Convoy Course predeployment.

DESIGN

Self-report data were collected at the beginning and end of training and then at 1, 3, 6, and 12 months postdeployment. Regression analyses were implemented, and participants were categorized into 4 groups based on TBI history for further statistical analysis.

RESULTS

Positive TBI history was associated with greater symptoms of insomnia and posttraumatic stress predeployment and persistence of insomnia symptoms, posttraumatic stress, and depression postdeployment. Positive TBI history and posttraumatic stress served as risk factors for head injury in Iraq, and SMs who reported a head injury during deployment also endorsed greater posttraumatic stress postdeployment than those without head injury. SMs with positive TBI history who also reported a new TBI in Iraq endorsed the greatest sleep and mental health problems across the study period.

CONCLUSIONS

This study provides valuable information regarding temporal relationships between TBI, sleep, and mental health problems among a combat military population. Findings have important implications from both prevention and clinical perspectives.

A history of sport-related concussion is associated with sustained deficits in conflict and error monitoring

Previous research has demonstrated long-term deficits in neurocognitive function in individuals with a history of sport-related concussion. The purpose of this study was to examine the relationship between a history of concussion and behavioral and event-related potential (ERP) indices of pre- and post-response conflict and error monitoring. A secondary aim was to determine whether years of high risk sport participation were related to impairments in these cognitive control processes. Forty-seven former athletes (age = 20.8 ± 2.2 years) with (n = 25; 5 females) and without (n = 22; 9 females) a history of concussion completed a modified flanker task while behavioral performance, N2, error-related negativity (ERN), and error positivity (Pe) components were assessed. An increase in post-response error-related (ERN) brain activity and a nonsignificant trend of increased pre-response conflict (N2) was observed in individuals with a prior sport-related concussion relative to non-concussed controls; however, no behavioral performance differences were found between groups. No significant associations were found between ERP and behavioral measures and the number of years of high-risk sport participation; however, time since last head injury was associated with shorter N2 latency. Together, these findings suggest a persistent impairment in cognitive control and error-related processing in individuals with a history of concussion. These findings are interpreted within the framework of the compensatory error-monitoring hypothesis.