Systematic Review of the Prognosis After Mild Traumatic Brain Injury in Adults: Cognitive, Psychiatric, and Mortality Outcomes: Results of the International Collaboration on Mild Traumatic Brain Injury Prognosis

The Association between Comorbidities and Comorbid Injuries on Treatment Outcome in Pediatric and Elderly Patients with Injuries in Korea: An Observational Study

We aimed to compare the characteristics and types of injuries affecting pediatric and elderly patients and to identify factors associated with treatment outcomes. We used data from the 2006−2017 Korea National Hospital Discharge Survey. The patients were divided into two groups, children (0−12 years) and elderly (≥65 years), based on their age at discharge. In total, 47,528 (11,842 children and 35,686 older adults) patients with injuries were identified. The number of deaths and the LOS were 36 (0.3%) and 7.6 days (±10.1), respectively, in the children group, and 861 (2.4%) and 18.5 days (±27.3), respectively, in the elderly group (p < 0.001). In the children group, there were increased odds for surgery among boys, Medicaid and health insurance subscribers, patients with multiple injuries, patients without a subdiagnosis, and an increasing number of hospital beds. In the elderly group, there were increased odds for surgery among women, Medicaid and health insurance subscribers, patients who died, patients with a single injury, patients with a subdiagnosis, and increasing numbers of hospital beds. Treatment outcomes could be improved by providing early diagnosis and prompt treatment in pediatric patients and by taking multilateral approaches for multiple injuries and comorbidities in elderly patients.

Effects of Mild Traumatic Brain Injury on Resting State Brain Network Connectivity in Older Adults

Older age is associated with worsened outcome after mild traumatic brain injury (mTBI) and a higher risk of developing persistent post-traumatic complaints. However, the effects of mTBI sequelae on brain connectivity at older age and their association with post-traumatic complaints remain understudied.We analyzed multi-echo resting-state functional magnetic resonance imaging data from 25 older adults with mTBI (mean age: 68 years, SD: 5 years) in the subacute phase (mean injury to scan interval: 38 days, SD: 9 days) and 20 age-matched controls. Severity of complaints (e.g. fatigue, dizziness) was assessed using self-reported questionnaires. Group independent component analysis was used to identify intrinsic connectivity networks (ICNs). The effects of group and severity of complaints on ICNs were assessed using spatial maps intensity (SMI) as a measure of within-network connectivity, and (static) functional network connectivity (FNC) as a measure of between-network connectivity.Patients indicated a higher total severity of complaints than controls. Regarding SMI measures, we observed hyperconnectivity in left-mid temporal gyrus (cognitive-language network) and hypoconnectivity in the right-fusiform gyrus (visual-cerebellar network) that were associated with group. Additionally, we found interaction effects for SMI between severity of complaints and group in the visual(-cerebellar) domain. Regarding FNC measures, no significant effects were found.In older adults, changes in cognitive-language and visual(-cerebellar) networks are related to mTBI. Additionally, group-dependent associations between connectivity within visual(-cerebellar) networks and severity of complaints might indicate post-injury (mal)adaptive mechanisms, which could partly explain post-traumatic complaints (such as dizziness and balance disorders) that are common in older adults during the subacute phase.

Blood-based biomarkers and traumatic brain injury-A clinical perspective

Blood-based biomarkers are promising tools to complement clinical variables and imaging findings in the diagnosis, monitoring and outcome prediction of traumatic brain injury (TBI). Several promising biomarker candidates have been found for various clinical questions, but the translation of TBI biomarkers into clinical applications has been negligible. Measured biomarker levels are influenced by patient-related variables such as age, blood-brain barrier integrity and renal and liver function. It is not yet fully understood how biomarkers enter the bloodstream from the interstitial fluid of the brain. In addition, the diagnostic performance of TBI biomarkers is affected by sampling timing and analytical methods. In this focused review, the clinical aspects of glial fibrillary acidic protein, neurofilament light, S100 calcium-binding protein B, tau and ubiquitin C-terminal hydrolase-L1 are examined. Current findings and clinical caveats are addressed.

Cognitive impairment in mild traumatic brain injury: a diffusion kurtosis imaging and volumetric study

BACKGROUND

A significant number of patients with mild traumatic brain injury (mTBI) would experience cognitive deficit.

PURPOSE

To investigate the brain structural changes in sub-acute mTBI by diffusion kurtosis imaging (DKI) and volumetric analysis, and to assess the relationship between brain structural changes and cognitive functions.

MATERIAL AND METHODS

A total of 23 patients with sub-acute mTBI and 24 control participants were recruited. All the participants underwent examinations of neuropsychological tests, DKI, and magnetic resonance imaging (MRI)-based morphological scans. Images were investigated using whole brain-based analysis and further regions of interest-based analysis for subcortical nuclei. The neuropsychological tests were compared between the mTBI and the control group. Correlation analysis was performed to examine the relationship between gray matter (GM) volume, DKI parameters, and cognitive functions.

RESULTS

Compared with control participants, mTBI patients performed worse in the domains of verbal memory, attention and executive function (P < 0.05). No regional GM volume differences were observed between the mTBI and control groups (P > 0.05). Using DKI, patients with mTBI showed lower mean kurtosis (MK) in widespread white matter (WM) regions and several subcortical nuclei (P < 0.05), and higher mean diffusivity (MD) in the right pallidum (P < 0.05). Lower MK value of multiple WM regions and several subcortical nuclei correlated with cognitive impairment (P < 0.05).

CONCLUSION

DKI was sensitive in detecting brain microstructural changes in patients with sub-acute mTBI showing lower MK value in widespread WM regions and several subcortical nuclei, which were statistically associated with cognitive deficits.

Morphometric changes in the cortex following acute mild traumatic brain injury

Morphometric changes in cortical thickness (CT), cortical surface area (CSA), and cortical volume (CV) can reflect pathological changes after acute mild traumatic brain injury (mTBI). Most previous studies focused on changes in CT, CSA, and CV in subacute or chronic mTBI, and few studies have examined changes in CT, CSA, and CV in acute mTBI. Furthermore, acute mTBI patients typically show transient cognitive impairment, and few studies have reported on the relationship between cerebral morphological changes and cognitive function in patients with mTBI. This prospective cohort study included 30 patients with acute mTBI (15 males, 15 females, mean age 33.7 years) and 27 matched healthy controls (12 males, 15 females, mean age 37.7 years) who were recruited from the Second Xiangya Hospital of Central South University between September and December 2019. High-resolution T1-weighted images were acquired within 7 days after the onset of mTBI. The results of analyses using FreeSurfer software revealed significantly increased CSA and CV in the right lateral occipital gyrus of acute-stage mTBI patients compared with healthy controls, but no significant changes in CT. The acute-stage mTBI patients also showed reduced executive function and processing speed indicated by a lower score in the Digital Symbol Substitution Test, and reduced cognitive ability indicated by a longer time to complete the Trail Making Test-B. Both increased CSA and CV in the right lateral occipital gyrus were negatively correlated with performance in the Trail Making Test part A. These findings suggest that cognitive deficits and cortical alterations in CSA and CV can be detected in the acute stage of mTBI, and that increased CSA and CV in the right lateral occipital gyrus may be a compensatory mechanism for cognitive dysfunction in acute-stage mTBI patients. This study was approved by the Ethics Committee of the Second Xiangya Hospital of Central South University, China (approval No. 086) on February 9, 2019.

Self-Reported Complaints as Prognostic Markers for Outcome After Mild Traumatic Brain Injury in Elderly: A Machine Learning Approach

Self-reported complaints are common after mild traumatic brain injury (mTBI). Particularly in the elderly with mTBI, the pre-injury status might play a relevant role in the recovery process. In most mTBI studies, however, pre-injury complaints are neither analyzed nor are the elderly included. Here, we aimed to identify which individual pre- and post-injury complaints are potential prognostic markers for incomplete recovery (IR) in elderly patients who sustained an mTBI. Since patients report many complaints across several domains that are strongly related, we used an interpretable machine learning (ML) approach to robustly deal with correlated predictors and boost classification performance. Pre- and post-injury levels of 20 individual complaints, as self-reported in the acute phase, were analyzed. We used data from two independent studies separately: UPFRONT study was used for training and validation and ReCONNECT study for independent testing. Functional outcome was assessed with the Glasgow Outcome Scale Extended (GOSE). We dichotomized functional outcome into complete recovery (CR; GOSE = 8) and IR (GOSE ≤ 7). In total 148 elderly with mTBI (median age: 67 years, interquartile range [IQR]: 9 years; UPFRONT: N = 115; ReCONNECT: N = 33) were included in this study. IR was observed in 74 (50%) patients. The classification model (IR vs. CR) achieved a good performance (the area under the receiver operating characteristic curve [ROC-AUC] = 0.80; 95% CI: 0.74-0.86) based on a subset of only 8 out of 40 pre- and post-injury complaints. We identified increased neck pain (p = 0.001) from pre- to post-injury as the strongest predictor of IR, followed by increased irritability (p = 0.011) and increased forgetfulness (p = 0.035) from pre- to post-injury. Our findings indicate that a subset of pre- and post-injury physical, emotional, and cognitive complaints has predictive value for determining long-term functional outcomes in elderly patients with mTBI. Particularly, post-injury neck pain, irritability, and forgetfulness scores were associated with IR and should be assessed early. The application of an ML approach holds promise for application in self-reported questionnaires to predict outcomes after mTBI.

Self-Rated Executive Function and Health-Related Quality of Life in Young Adults With Persistent Post-Concussion Symptoms: A Cross-Sectional Study

OBJECTIVE

To assess self-reported executive dysfunction in young adult patients with persistent post-concussion symptoms (PCS) 2-6 months post-injury, and the association with self-reported Health-Related Quality of Life (HRQoL).

METHOD

This cross-sectional study carried out in a hospital setting was a secondary analysis of data from a separate randomized trial testing the effect of a novel intervention, "Get going After concussIoN " (GAIN), for persistent PCS. Patients (18-30 years) were recruited from a clinical cohort of patients with a hospital diagnosis of concussion or referred by primary care physicians. Main measures were The Behaviour Rating Inventory of Executive Function-Adult Version providing two index scores, that is, the Metacognitive Index (MI) and the Behavioural Regulation Index (BRI), and the Quality of Life after Brain Injury-Overall Scale.

RESULTS

Compared with normative data, patients had elevated scores (i.e., worse functioning) on both the MI and the BRI. In linear regression analysis, the MI score, but not the BRI score, was negatively associated with self-reported HRQoL (MI: slope = -.27, 95% confidence interval, CI [-.53, -.02], p = .03; BRI: slope = -.19, 95% CI [-.49, .13], p = .24), suggesting a positive association of subjective executive dysfunction and lower HRQoL. However, the association was attenuated after adjustment for self-reported psychological distress (MI: slope = -.09, 95% CI [-.34, .17], p = .51).

CONCLUSION

Self-reported executive dysfunction is common in young adult patients with persistent PCS, but not strongly associated with decreased HRQoL after adjusting for concurrent psychological distress.

Collaborative Goal Setting: A Clinical Approach for Adults With Mild Traumatic Brain Injury

Purpose Speech-language pathologists (SLPs) have many available procedural options when setting treatment goals. Extant literature supports goal setting protocols that include and value the perspectives of the client; however, in practice, rehabilitation professionals may lean toward expert models of care when planning treatment. Our purpose is to describe a newly developed approach for SLPs and individuals with mild traumatic brain injury (mTBI) to work together to build meaningful, relevant goals. Method We utilized a multiple case study format to exemplify goal setting procedures. Specifically, we describe procedures and outcomes for a 29-year-old female 28 days postinjury and a 70-year-old male 9 months postinjury. Results Clients who engaged in this protocol worked collaboratively with a clinician to identify strengths and challenges postinjury, select and prioritize goal areas, and discuss and develop meaningful, personalized treatment activities. For both participants, use of the proposed protocol resulted in meaningful goals that addressed their self-reported deficits as well as their respective cognitive-linguistic deficits noted on objective, standardized measures. Conclusions Clinician and client collaboration during treatment goal development can facilitate increased client motivation and functional outcomes. The described approach is feasible from a clinical resource standpoint and promotes a systematic approach to placing the client at the forefront of clinical decision making to enhance therapeutic gains. Such client-centered approaches may be particularly valuable for individuals with mTBI who experience substantial cognitive and communicative challenges but may maintain high levels of self-awareness postinjury.

Prevalence of insomnia and insomnia symptoms following mild-traumatic brain injury: A systematic review and meta-analysis

Sleep is commonly disrupted following mild traumatic brain injury (mTBI), however there is a lack of consensus in the existing literature regarding the prevalence of insomnia/insomnia symptoms after injury. The aim of this review was to conduct a systematic review and meta-analysis of insomnia and insomnia symptoms' prevalence following mTBI. Full-text articles published in English in peer-reviewed journals, including adults with a clinical or self-reported mild traumatic brain injury diagnosis, were eligible for inclusion. Studies that assessed insomnia/insomnia symptoms after injury were included. Of the 2091 records identified, 20 studies were included in the review. 19 of these were meta-analysed (n = 95,195), indicating high heterogeneity among studies. Subgroup analyses indicated pooled prevalence estimates of post-mTBI insomnia disorder of 27.0% (95% CI 6.49-54.68) and insomnia symptoms of 71.7% (95% CI 60.31-81.85). The prevalence of insomnia is significantly higher in individuals who have sustained mild traumatic brain injury compared to prevalence estimates reported in the general population but high heterogeneity and methodological differences among studies make it difficult to provide reliable prevalence estimates. Future research should continue to advance our understanding of the onset, progression and impact of post-mild traumatic brain injury insomnia to promote the recovery and wellbeing of affected individuals. PROSPERO registration CRD42020168563.

Change in Learning and Memory Partially Mediates Effects of Compensatory Cognitive Training on Self-Reported Cognitive Symptoms

OBJECTIVE

To examine associations among compensatory cognitive training (CCT), objective cognitive functioning, and self-reported cognitive symptoms. We examined whether change in objective cognitive functioning associated with participation in CCT at 10-week follow-up mediates change in self-reported cognitive symptoms associated with CCT at 15-week follow-up.

SETTING

Three VA outpatient mental health clinics.

PARTICIPANTS

Veterans with a history of mild traumatic brain injury who reported cognitive deficits.

DESIGN

Randomized controlled trial post hoc causal mediation analysis.

MAIN MEASURES

Self-reported cognitive symptoms were measured by the Prospective-Retrospective Memory Questionnaire and the Multiple Sclerosis Neuropsychological Screening Questionnaire. Objective cognitive functioning was measured using a battery of neuropsychological tests.

RESULTS

Improvement on the Hopkins Verbal Learning Test-Revised (HVLT-R) Delayed Recall test mediated the association between participation in CCT and decrease in the Prospective-Retrospective Memory Questionnaire total score. Improvement on the HVLT-R Total Recall and HVLT-R Delayed Recall tests both meditated the association between participation in CCT and decrease in the Multiple Sclerosis Neuropsychological Screening Questionnaire total score. No other measures of objective cognitive functioning were significant mediators.

CONCLUSION

Patients' perceptions of cognitive symptom improvement due to CCT are partially mediated by learning and memory, though these subjective improvements occur regardless of other changes in objective cognitive functioning associated with CCT.

Nonpharmacological Treatment of Persistent Postconcussion Symptoms in Adults: A Systematic Review and Meta-analysis and Guideline Recommendation

IMPORTANCE

Persistent (>4 weeks) postconcussion symptoms (PPCS) are challenging for both patients and clinicians. There is uncertainty about the effect of commonly applied nonpharmacological treatments for the management of PPCS.

OBJECTIVE

To systematically assess and summarize evidence for outcomes related to 7 nonpharmacological interventions for PPCS in adults (aged >18 years) and provide recommendations for clinical practice.

DATA SOURCES

Systematic literature searches were performed via Embase, MEDLINE, PsycINFO, CINAHL, PEDro, OTseeker, and Cochrane Reviews (via MEDLINE and Embase) from earliest possible publication year to March 3, 2020. The literature was searched for prior systematic reviews and primary studies. To be included, studies had to be intervention studies with a control group and focus on PPCS.

STUDY SELECTION

A multidisciplinary guideline panel selected interventions based on frequency of use and need for decision support among clinicians, including early information and advice, graded physical exercise, vestibular rehabilitation, manual treatment of neck and back, oculomotor vision treatment, psychological treatment, and interdisciplinary coordinated rehabilitative treatment. To be included, studies had to be intervention studies within the areas of the predefined clinical questions, include a control group, and focus on symptoms after concussion or mild traumatic brain injury.

DATA EXTRACTION AND SYNTHESIS

Extraction was performed independently by multiple observers. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for data abstraction and data quality assessment. Included studies were assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) tool and the Cochrane Risk of Bias (randomized clinical trials) tool. Meta-analysis was performed for all interventions where possible. Random-effects models were used to calculate pooled estimates of effects. The level and certainty of evidence was rated and recommendations formulated according to the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework.

MAIN OUTCOMES AND MEASURES

All outcomes were planned before data collection began according to a specified protocol. The primary outcomes were the collective burden of PPCS and another outcome reflecting the focus of a particular intervention (eg, physical functioning after graded exercise intervention).

RESULTS

Eleven systematic reviews were identified but did not contribute any primary studies; 19 randomized clinical trials comprising 2007 participants (1064 women [53.0%]) were separately identified and included. Evidence for the 7 interventions ranged from no evidence meeting the inclusion criteria to very low and low levels of evidence. Recommendations were weak for early information and advice, graded physical exercise, vestibular rehabilitation, manual treatment of the neck and back, psychological treatment, and interdisciplinary coordinated rehabilitative treatment. No relevant evidence was identified for oculomotor vision treatment, so the panel provided a good clinical practice recommendation based on consensus.

CONCLUSIONS AND RELEVANCE

Based on very low to low certainty of evidence or based on consensus, the guideline panel found weak scientific support for commonly applied nonpharmacological interventions to treat PPCS. Results align with recommendations in international guidelines. Intensified research into all types of intervention for PPCS is needed.

Attachment and symptom reporting in adolescents and young adults after a concussion

BACKGROUND

The incidence of hospital-treated concussion is 100-300/100,000 person years. Reporting of long-lasting post-concussion symptoms (PCS) is estimated at 5-15%. Attachment insecurity is a potential vulnerability factor for physical illness and poorer disease outcomes in general. This study aimed to explore associations between attachment insecurity and PCS in young people sustaining a concussion.

METHODS

This cross-sectional study was embedded in a cohort of 15-30-year-old patients (n = 3080) 3 months after sustaining a concussion. Data were obtained from a database and questionnaires. PCS were measured by the Rivermead Post-Concussion Symptoms Questionnaire and attachment dimensions (anxiety and avoidance) by the Experiences in Close Relationships-Relationship Structures Questionnaire. Multiple linear regression models were performed to investigate the association between the attachment dimensions and PCS with adjustment for demographic, injury-related and psychological factors and with additional testing for interaction between the attachment dimensions.

RESULTS

In the final study sample, comprising 973 patients (31.6%), we found an interaction between the attachment dimensions. Hence, the effect of attachment anxiety on PCS was statistically insignificant at low avoidance (25th percentile) but significant at high avoidance (75th percentile, β = 0.64 (95%CI: 0.02; 1.26)), whereas the effect of attachment avoidance was significant regardless of level of attachment anxiety (25th percentile, β = 1.09 (95%CI: 0.18; 2.01); 75th percentile, β = 2.71 (95%CI: 1.80; 3.61)).

CONCLUSION

Attachment insecurity, especially characterised by high avoidance in combination with high anxiety, also called fearful attachment, is associated with PCS. Considering the attachment perspective can potentially improve health care for this patient group.

Health Care Resource Utilization and Costs for Adults With Mild Traumatic Brain Injury With Chronic Vestibular Impairment

OBJECTIVE

To quantify the economic burden of all-cause health care resource utilization (HCRU) among adults with and without chronic vestibular impairment (CVI) after a mild traumatic brain injury (mTBI).

DESIGN

Retrospective matched cohort study.

SETTING

IQVIA Integrated Data Warehouse.

PARTICIPANTS

People with mTBI+CVI (n=20,441) matched on baseline age, sex, year of mTBI event, and Charlson Comorbidity Index (CCI) score to people with mTBI only (n=20,441) (N=40,882).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

All-cause health HCRU and costs at 12 and 24 months post mTBI diagnosis.

RESULTS

People with mTBI+CVI had significantly higher all-cause HCRU and costs at both time points than those with mTBI only. Multivariable regression analysis showed that, when controlling for baseline variables, costs of care were 1.5 times higher for mTBI+CVI than mTBI only.

CONCLUSIONS

People who developed CVI after mTBI had greater overall HCRU and costs for up to 2 years after the injury event compared with people who did not develop CVI after controlling for age, sex, region, and CCI score. Further research on access to follow-up services and effectiveness of interventions to address CVI is warranted.

Improving Outcomes for Work-Related Concussions: A Mental Health Screening and Brief Therapy Model

OBJECTIVE

This study assessed the efficacy of a neurocognitive screening evaluation and brief therapy model to improve RTW outcomes for workers who experienced mild head injuries.

METHODS

Patients referred were evaluated using a neurocognitive and psychological screening battery. Work-focused cognitive behavioral therapy was provided when appropriate, addressing the role of negative emotional adjustment and functional sleep disturbance in prolonging recovery.

RESULTS

Average time to RTW was 7 weeks post-evaluation, despite workers being off an average of 10 months between injury and referral dates. Overall, 99% were released to full-duty work without restrictions or accommodations.

CONCLUSIONS

This study demonstrates the favorable outcomes achieved via a structured, clinically driven program for workers who experience head-involved injuries, validating previous research on the importance of recognizing the role of psychological factors in prolonging concussion recovery.

Prognostic factors for persistent symptoms in adults with mild traumatic brain injury: protocol for an overview of systematic reviews

BACKGROUND

Mild traumatic brain injury (mTBI) is an increasing public health problem that can lead to persistent symptoms that have several functional consequences. Understanding the prognosis of a condition is an important component of clinical decision-making and can help guide the prevention of long-term disabilities of patients with mTBI. Several studies and systematic reviews have been conducted in order to understand prognosis of chronic symptoms following mTBI. We aim to synthesize evidence from systematic reviews on factors that affect the risk of persistent symptoms in mTBI-affected adults.

METHODS

We will conduct an overview of systematic reviews following steps described in the Cochrane Handbook. We will search in Cochrane, Medline, CINAHL, Embase, PsycINFO, and Epistemonikos for systematic reviews about the prognosis of persistent symptoms following mTBI in the adult population. Two reviewers will independently screen all references and then select eligible reviews based on eligibility criteria. A data extraction grid will be used to extract relevant information. The risk of bias in the included reviews will be assessed using the ROBIS tool. Data will be synthesized into a comprehensive conceptual model in order to have a better understanding of the predictive factors of post-concussion symptoms following mTBI.

DISCUSSION

Results will help multiple stakeholders, such as clinicians and rehabilitation program managers, to understand the prognosis of long-term consequences following mTBI. It could guide stakeholders to recognize their patients' prognostic factors and to invest their time and resources in patients who need it the most.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020176676 .

Investigating the Effect of Fatigue and Psychological Distress on Information Processing Speed in the Postacute Period After Mild Traumatic Brain Injury in Premorbidly Healthy Adults

Impairments in processing speed under conditions of increasing cognitive load have been reported in individuals with mild traumatic brain injury (mTBI). In other conditions that are also associated with white matter disruption, both psychological distress and fatigue have been shown to underlie this impairment.

OBJECTIVE

the current study aimed to investigate whether slowing of processing abilities under conditions of greater cognitive load is independent of fatigue and psychological status in premorbidly healthy individuals with subacute mTBI.

METHOD

using a prospective observational design, we examined 84 individuals with mTBI approximately 8 weeks after injury and 47 healthy control (HC) participants. They were assessed with the Symbol Digit Modality Test, an n-back task and a rate of gain of information choice reaction time task that conforms to Hick's law. Participants were also assessed with measures of fatigue and psychological status.

RESULTS

as expected, findings revealed no group differences on simple reaction time tasks, but as task complexity increased, the mTBI group performed more slowly than the HC group. This group difference occurred independently of fatigue and psychological distress levels and was associated with a moderate effect size.

CONCLUSIONS

during the subacute period after mTBI, premorbidly healthy individuals demonstrate impairment in their ability to rapidly process information as the cognitive load of the task increases beyond simple reaction time requirements. Examination of whether these changes affect resumption of premorbid roles is warranted.

Brain Volume in Veterans: Relationship to Posttraumatic Stress Disorder and Mild Traumatic Brain Injury

OBJECTIVE

Clarify associations between diagnosis of posttraumatic stress disorder (PTSD) and deployment traumatic brain injury (TBI) on salient regional brain volumes in returning combat veterans.

PARTICIPANTS

Iraq and Afghanistan era combat veterans, N = 163, 86.5% male.

MAIN MEASURES

Clinician-administered PTSD Scale (CAPS-5), Mid-Atlantic MIRECC Assessment of TBI (MMA-TBI), magnetic resonance imaging.

METHODS

Hierarchical regression analyses evaluated associations and interactions between current and lifetime PTSD diagnosis, deployment TBI, and bilateral volume of hippocampus, anterior cingulate cortex, amygdala, orbitofrontal cortex, precuneus, and insula.

RESULTS

Deployment TBI was associated with lower bilateral hippocampal volume (P = .007-.032) and right medial orbitofrontal cortex volume (P = .006). Neither current nor lifetime PTSD diagnosis was associated with volumetric outcomes beyond covariates and deployment TBI.

CONCLUSION

History of deployment TBI is independently associated with lower volumes in hippocampus and medial orbitofrontal cortex. These results support TBI as a potential contributing factor to consider in reduced cortical volume in PTSD.

Moderators of gene-outcome associations following traumatic brain injury

The field of genomics is the principal avenue in the ongoing development of precision/personalised medicine for a variety of health conditions. However, relating genes to outcomes is notoriously complex, especially when considering that other variables can change, or moderate, gene-outcome associations. Here, we comprehensively discuss moderation of gene-outcome associations in the context of traumatic brain injury (TBI), a common, chronically debilitating, and costly neurological condition that is under complex polygenic influence. We focus our narrative review on single nucleotide polymorphisms (SNPs) of three of the most studied genes (apolipoprotein E, brain-derived neurotrophic factor, and catechol-O-methyltransferase) and on three demographic variables believed to moderate associations between these SNPs and TBI outcomes (age, biological sex, and ethnicity). We speculate on the mechanisms which may underlie these moderating effects, drawing widely from biomolecular and behavioural research (n = 175 scientific reports) within the TBI population (n = 72) and other neurological, healthy, ageing, and psychiatric populations (n = 103). We conclude with methodological recommendations for improved exploration of moderators in future genetics research in TBI and other populations.

Fatigue following mild traumatic brain injury relates to visual processing and effort perception in the context of motor performance

INTRODUCTION

Following mild traumatic brain injury (mTBI), a substantial number of patients experience disabling fatigue for months after the initial injury. To date, the underlying mechanisms of fatigue remain unclear. Recently, it was shown that mTBI patients with persistent fatigue do not demonstrate increased performance fatigability (i.e., objective performance decline) during a sustained motor task. However, it is not known whether the neural activation required to sustain this performance is altered after mTBI.

METHODS

Blood oxygen level-dependent (BOLD) fMRI data were acquired from 19 mTBI patients (>3 months post-injury) and 19 control participants during two motor tasks. Force was recorded from the index finger abductors of both hands during submaximal contractions and a 2-minute maximal voluntary contraction (MVC) with the right hand. Voluntary muscle activation (i.e., CNS drive) was indexed during the sustained MVC using peripheral nerve stimulation. Fatigue was quantified using the Fatigue Severity Scale (FSS) and Modified Fatigue Impact Scale (MFIS). Questionnaire, task, and BOLD data were compared across groups, and linear regression was used to evaluate the relationship between BOLD-activity and fatigue in the mTBI group.

RESULTS

The mTBI patients reported significantly higher levels of fatigue (FSS: 5.3 vs. 2.6, p < 0.001). Both mTBI- and control groups demonstrated significant performance fatigability during the sustained MVC, but no significant differences in task performance or BOLD-activity were observed between groups. However, mTBI patients reporting higher FSS scores showed increased BOLD-activity in the bilateral visual cortices (mainly extrastriate) and the left midcingulate gyrus. Furthermore, across all participants mean voluntary muscle activation during the sustained MVC correlated with long lasting post-contraction BOLD-activation in the right insula and midcingulate cortex.

CONCLUSION

The fMRI findings suggest that self-reported fatigue in mTBI may relate to visual processing and effort perception. Long lasting activation associated with high levels of CNS drive might be related to changes in cortical homeostasis in the context of high effort.

Psychological flexibility in mild traumatic brain injury: an evaluation of measures

PRIMARY OBJECTIVE

In this study, we examined the psychometric properties of measures of psychological flexibility in a mild traumatic brain injury (mTBI) sample.

METHOD AND PROCEDURES

Adults who sustained a mTBI (n = 112) completed the Acceptance and Action Questionnaire - Acquired Brain Injury reactive avoidance subscale (AAQ-ABI (RA). Exploratory factor analysis and Rasch analysis were conducted to evaluate the facture structure, dimensionality, and differential item functioning. Construct validity was determined by correlating the AAQ-ABI (RA) with the Acceptance and Action Questionnaire-Revised (AAQ-II) and Fear Avoidance after Traumatic Brain Injury (FAB-TBI).

MAIN OUTCOME AND RESULTS

The AAQ-ABI (RA) was found to have strong internal consistency (Cronbach's α = 0.87). Consistent with previous findings, the AAQ-ABI (RA) had one distinct factor. Fit to the unidimensional Rasch model was adequate (χ² (18) = 22.5, p = .21) with no evidence of differential item functioning across person factors examined. The AAQ-ABI (RA) also had expected relationships with theoretically relevant constructs.

CONCLUSIONS

The AAQ-ABI (RA) appears to be a psychometrically sound measure of psychological flexibility in mTBI.

Cerebral perfusion disturbances in chronic mild traumatic brain injury correlate with psychoemotional outcomes

The study explored associations between hemodynamic changes and psychoemotional status in 32 patients with chronic mild traumatic brain injury (mTBI) and 31 age-matched healthy volunteers. Cerebral blood flow (CBF) and cerebral blood volume (CBV) values were obtained using Dynamic Susceptibility Contrast Magnetic Resonance Imaging in brain regions suspected to play a role in anxiety and depression. Patients were administered self-report measures of anxiety and depression symptoms and underwent neuropsychological assessment. As a group mTBI patients scored significantly below age- and education-adjusted population norms on multiple cognitive domains and reported high rates of anxiety and depression symptomatology. Significantly reduced CBF values were detected in the mTBI group compared to controls in dorsolateral prefrontal areas, putamen, and hippocampus, bilaterally. Within the mTBI group, depressive symptomatology was significantly associated with lower perfusion in the left anterior cingulate gyrus and higher perfusion in the putamen, bilaterally. The latter association was independent from verbal working memory capacity. Moreover, anxiety symptomatology was associated with lower perfusion in the hippocampus (after controlling for verbal episodic memory difficulties). Associations between regional perfusion and psychoemotional scores were specific to depression or anxiety, respectively, and independent of the presence of visible lesions on conventional MRI. Results are discussed in relation to the role of specific limbic and paralimbic regions in the pathogenesis of symptoms of depression and anxiety.

Number of Concussions Does Not Affect Treatment Response to Cognitive Rehabilitation Interventions Following Mild TBI in Military Service Members

OBJECTIVE

The study objective was to determine whether number of concussions would affect symptom improvement following cognitive rehabilitation (CR) interventions.

METHOD

Service members (N = 126) with concussion history completed a 6-week randomized control trial of CR interventions. Participants were stratified based on self-reported lifetime concussion frequency. Outcome measures included the Paced Auditory Serial Addition Test (PASAT), the Global Severity Index (GSI) from the Symptom Checklist-90-Revised, and the Key Behaviors Change Inventory (KBCI).

RESULTS

Mixed-model analyses of variance revealed a significant main effect for time on cognitive, psychological, and neurobehavioral functioning. A significant main effect for the number of concussions was observed for GSI and KBCI, but not PASAT. Interactions between the number of concussions and time were not significant for any of the outcome variables.

CONCLUSIONS

Over the 6-week interval, improvements were found for all participants across all outcome measures. Number of concussions did not affect improvements over time.

Pharmacotherapy for Treatment of Cognitive and Neuropsychiatric Symptoms After mTBI

OBJECTIVES

Cognitive and neuropsychiatric symptoms are extremely common following mild traumatic brain injury (TBI), also known as concussion. Although most patients will recovery rapidly, a significant minority go on to experience persistent symptoms. There are currently no FDA-approved medications for treatment of cognitive and neuropsychiatric problems in the context of mild TBI, yet a number of agents are prescribed "off-label" for these complaints. Rigorous trials are lacking, but there are a number of open-label studies, and some small randomized controlled trials that support the safety and possible efficacy of pharmacotherapies in this population. Clinical trials conducted in samples with more severe brain injuries can also serve as a guide.

METHODS

Review of the literature.

RESULTS & CONCLUSIONS

There is the most support in the literature for the neurostimulant methylphenidate for treatment of mild TBI-related cognitive dysfunction, and the selective serotonin reuptake inhibitor, sertraline, for the treatment of postinjury depression. There is clearly a need for more well-designed studies to guide clinicians in selecting the appropriate medication and dose. Without clear guidance from the literature, a cautious approach of starting low and titrating slowly is recommended.

Mapping Stakeholder Perspectives on Engagement in Concussion Research to Theory

BACKGROUND

Involving stakeholders has been acknowledged as a way to improve quality and relevance in health research. The mechanisms that support effective research engagement with stakeholders have not been studied in the area of concussion. Concussion is a large public health concern worldwide with billions of dollars spent on health care services and research with improvements in care and service delivery not moving forward as quickly as desired. Enabling effective stakeholder engagement could improve concussion research and care.

OBJECTIVE

The aim of the study was to identify potential benefits, challenges, and motivators to engaging in research by gathering the perspectives of adults with lived experience of concussion.

METHODS

A thematic analysis of qualitative responses collected from a convenience sample attending a provincial brain injury conference (n = 60) was undertaken using open coding followed by axial coding.

RESULTS

Four themes regarding benefits to engagement emerged: first-hand account, meaningful recovery, research relevance, and better understanding of gaps. Three forces inhibited engagement: environmental barriers, injury-related constraints, and personal deterrents. Four enablers supported engagement: focus on positive impact, build connections, create a supportive environment, and provide financial assistance.

CONCLUSIONS

Understanding stakeholder's perspectives on research engagement is an important issue that may serve to improve research quality. There may be unique nuances at play with injury-specific stakeholders that require researchers to consider a balance between reducing inhibitors while supporting enablers. These findings are preliminary and limited. Nevertheless, they provide needed insight and guidance for ongoing investigation regarding improvement of stakeholder engagement in concussion research.

Cognitive performance in older adults at three months following mild traumatic brain injury

Introduction: In the context of limited research assessing outcomes following mild traumatic brain injury (mTBI) in older adults, this study evaluated cognitive outcomes through prospective memory, and expected that performance of an older mTBI group (≥65 years) would be lower compared to orthopedic and community controls. The study also explored whether cognitive resources (retrospective memory, executive function) moderated any association between presenting Glasgow Coma Scale (GCS) and prospective memory.Method: At three-months post-injury, a mTBI group (n = 39), an orthopedic control group (n = 63), and a community control group (n = 46) completed a neuropsychological assessment, including (i) prospective memory, using a standardized paper-and-pencil task (Cambridge Prospective Memory Test), an augmented reality task and a naturalistic task, and (ii) standardized measures of retrospective memory (Hopkins Verbal Learning Test) and executive function (Trail Making Test). Group performances were compared, and bootstrapped moderation analyses evaluated the role of cognitive resources in the relationship between GCS and prospective memory outcome.Results: The mTBI group, as compared to community controls, performed significantly lower on the augmented reality task (d = -0.64 to d = -0.79), and there was a small-moderate but non-significant effect (d = -0.45) on the naturalistic task. There were no differences between the mTBI group and orthopedic controls. Retrospective memory was a unique predictor of the augmented reality task (B = 1.83) and moderated the relationship between presenting GCS and the naturalistic task (B = -5.60). Executive function moderated the association between presenting GCS and augmented reality (B = -1.13) and naturalistic task (B = -1.57).Conclusions: At three-months post-mTBI, older adults are at risk of poor cognitive performance; and the relationship between GCS and prospective memory can be moderated by cognitive resources. Further follow-up is indicated to determine whether impairments resolve or persist over time.

The Association of Post-Concussion and Post-Traumatic Stress Disorder Symptoms with Health-Related Quality of Life, Health Care Use and Return-to-Work after Mild Traumatic Brain Injury

Patients with mild traumatic brain injury (mTBI) are at risk for post-concussion (PC) symptoms and post-traumatic stress disorder (PTSD). The co-occurrence of PC and PTSD symptoms after mTBI in relation to health-related quality of life (HRQoL), health care utilization, and return to work has not yet been investigated. PC and PTSD symptoms were measured six months post-TBI by respectively the Rivermead Post-Concussion Symptoms Questionnaire (RPQ) and the Post-Traumatic Stress Disorder Checklist for DSM-5 (PCL-5). Of the 1566 individuals after mTBI who met the inclusion criteria, 26.1% experienced PC symptoms (RPQ ≥16). Additionally, 9.8% experienced PTSD symptoms (PCL-5 ≥ 33), of which the vast majority (81%) also reported experiencing PC symptoms. Differences between patients with no/mild symptoms, with only PC, only PTSD, and both PC and PTSD symptoms in HRQoL, return to work, and rehabilitation were analyzed using logistic and linear regression analyses. Patients with PC and/or PTSD symptoms reported lower HRQoL, higher rates of rehabilitation, and lower return to work rates compared to patients with no/mild symptoms. Patients with both PC and PTSD symptoms reported significantly lower HRQoL (B = -2.73, CI = -4.65; -0.83, p < 0.001) compared to those with only PC symptoms, while there were no significant differences in their ongoing rehabilitation care (OR = 1.39, CI = 0.77-2.49, p = 0.272) and return to work rates (OR = 0.49, CI = 0.15-1.63, p = 0.246) at six months. These results underline the importance of the diagnosis and appropriate treatment of patients with mTBI, experiencing PC and/or PTSD symptoms.

Predicting outcome following mild traumatic brain injury: protocol for the longitudinal, prospective, observational Concussion Recovery (CREST) cohort study

INTRODUCTION

Mild traumatic brain injury (mTBI) is a complex injury with heterogeneous physical, cognitive, emotional and functional outcomes. Many who sustain mTBI recover within 2 weeks of injury; however, approximately 10%-20% of individuals experience mTBI symptoms beyond this 'typical' recovery timeframe, known as persistent post-concussion symptoms (PPCS). Despite increasing interest in PPCS, uncertainty remains regarding its prevalence in community-based populations and the extent to which poor recovery may be identified using early predictive markers.

OBJECTIVE

(1) Establish a research dataset of people who have experienced mTBI and document their recovery trajectories; (2) Evaluate a broad range of novel and established prognostic factors for inclusion in a predictive model for PPCS.

METHODS AND ANALYSIS

The Concussion Recovery Study (CREST) is a prospective, longitudinal observational cohort study conducted in Perth, Western Australia. CREST is recruiting adults aged 18-65 from medical and community-based settings with acute diagnosis of mTBI. CREST will create a state-wide research dataset of mTBI cases, with data being collected in two phases. Phase I collates data on demographics, medical background, lifestyle habits, nature of injury and acute mTBI symptomatology. In Phase II, participants undergo neuropsychological evaluation, exercise tolerance and vestibular/ocular motor screening, MRI, quantitative electroencephalography and blood-based biomarker assessment. Follow-up is conducted via telephone interview at 1, 3, 6 and 12 months after injury. Primary outcome measures are presence of PPCS and quality of life, as measured by the Post-Concussion Symptom Scale and the Quality of Life after Brain Injury questionnaires, respectively. Multivariate modelling will examine the prognostic value of promising factors.

ETHICS AND DISSEMINATION

Human Research Ethics Committees of Royal Perth Hospital (#RGS0000003024), Curtin University (HRE2019-0209), Ramsay Health Care (#2009) and St John of God Health Care (#1628) have approved this study protocol. Findings will be published in peer-reviewed journals and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

ACTRN12619001226190.

Differential effects of deployment and nondeployment mild TBI on neuropsychological outcomes

Objective: Mild traumatic brain injury (TBI) that occurs in a deployment environment is characteristically different from mild TBI that occurs outside of deployment. This study evaluated differential and interaction effects of deployment and nondeployment mild TBI on cognitive and behavioral health outcomes. Research Method: Combat veterans (N = 293) who passed performance-validity measures completed the Mid-Atlantic MIRECC Assessment of TBI (MMA-TBI), Clinician-Administered Posttraumatic Stress Disorder (PTSD) Scale (CAPS-5), a neuropsychological assessment battery, and self-report questionnaires. A 2 × 2 × 2 analysis of variance (ANOVA) was conducted to evaluate the main and interaction effects across mild TBI groups and PTSD diagnosis. Results: Deployment TBI was associated with poorer outcomes on several cognitive tests: Wechsler Adult Intelligence Scale, 4th edition (WAIS-IV); Working Memory Index (WMI; p = .018); Trail Making Test A (TMT-A; p < .001); and Trail Making Test B (TMT-B; p = .002). Deployment TBI and PTSD were also associated with increased PTSD, depressive, and neurobehavioral symptoms; pain interference; and poorer sleep quality. Nondeployment TBI had no effect on cognitive performance and was associated only with poorer sleep quality. PTSD had the strongest associations with symptom measures and deployment TBI with cognitive outcomes. There were no significant interaction effects after adjusting for multiple comparisons. Conclusions: Remote outcomes associated with mild deployment TBI are different from those associated with nondeployment mild TBI and are robust beyond PTSD. This suggests that the environment surrounding a TBI event influences cognitive and symptom sequelae. Veterans who experience mild TBI during deployment may report changes in cognition, but most will continue to function within the expected range. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

American Academy of Clinical Neuropsychology (AACN) 2021 consensus statement on validity assessment: Update of the 2009 AACN consensus conference statement on neuropsychological assessment of effort, response bias, and malingering

Objective: Citation and download data pertaining to the 2009 AACN consensus statement on validity assessment indicated that the topic maintained high interest in subsequent years, during which key terminology evolved and relevant empirical research proliferated. With a general goal of providing current guidance to the clinical neuropsychology community regarding this important topic, the specific update goals were to: identify current key definitions of terms relevant to validity assessment; learn what experts believe should be reaffirmed from the original consensus paper, as well as new consensus points; and incorporate the latest recommendations regarding the use of validity testing, as well as current application of the term 'malingering.' Methods: In the spring of 2019, four of the original 2009 work group chairs and additional experts for each work group were impaneled. A total of 20 individuals shared ideas and writing drafts until reaching consensus on January 21, 2021. Results: Consensus was reached regarding affirmation of prior salient points that continue to garner clinical and scientific support, as well as creation of new points. The resulting consensus statement addresses definitions and differential diagnosis, performance and symptom validity assessment, and research design and statistical issues. Conclusions/Importance: In order to provide bases for diagnoses and interpretations, the current consensus is that all clinical and forensic evaluations must proactively address the degree to which results of neuropsychological and psychological testing are valid. There is a strong and continually-growing evidence-based literature on which practitioners can confidently base their judgments regarding the selection and interpretation of validity measures.

Relationship between depression, community integration and life satisfaction following mild traumatic brain injury

Purpose: Compared to studies on moderate and severe traumatic brain injury (TBI), less literature exists concerning the consequences of mild traumatic brain injury (mTBI) on community integration and life satisfaction, especially in the early phase of recovery. Moreover, a better understanding of the variables that contribute to community integration and life satisfaction is still needed. The aim of the study was to assess the association of mood, fatigue and post-concussive symptoms with community integration and life satisfaction early following mTBI.Research method: A total of 85 participants aged between 18 and 61 years who sustained mTBI were included. Participants answered web-based questionnaires measuring anxiety and depression symptoms, fatigue, post-concussive symptoms, community integration and life satisfaction in the first three months post mTBI.Results: Post-concussive symptoms, fatigue and anxiety were not associated with community integration or life satisfaction. However, depressive symptoms were negatively associated with community integration and life satisfaction.Conclusions: Among all acute post-concussive symptoms following mTBI, depressive symptoms seem to have strongest relationship with community integration and life satisfaction. Acute psychological intervention targeting these symptoms is strongly recommended.

Sleep moderates symptom experience in combat veterans

BACKGROUND

Though sleep disturbance has shown to negatively affect outcomes related to post-deployment conditions, it is unclear whether and how sleep disturbance affects mental health symptoms beyond these conditions. We evaluated the independent and moderating effects of sleep quality on posttraumatic stress disorder (PTSD), depressive, and neurobehavioral symptoms beyond mild traumatic brain injury (TBI) and PTSD diagnosis.

METHODS

Participants were 274 US combat veterans who deployed after 9/11. All completed diagnostic TBI and PTSD interviews and self-report measures of sleep quality, as well as PTSD, depressive, and neurobehavioral symptoms. Only those who passed symptom validity were included in analyses. Hierarchical regression evaluated the contribution of sleep quality to outcomes beyond PTSD and mild TBI. Moderation analyses evaluated interactions between mild TBI, PTSD, and sleep quality on symptom outcomes.

RESULTS

Mild TBI was only significantly associated with PTSD (p = .006) and neurobehavioral (p = .003) symptoms. PTSD diagnosis was associated with PTSD (p < .001), depressive (p < .001), and neurobehavioral symptoms (p < .001) beyond mild TBI. Sleep quality explained additional significant variance in all three outcome measures (p < .001), and also significantly moderated the effects of PTSD diagnosis on neurobehavioral symptoms (ΔR² = .01, p = .023).

LIMITATIONS

Sleep was evaluated subjectively and therefore must be interpreted in this context.

CONCLUSIONS

These results provide support that sleep quality is an independent contributing factor to health outcomes in post-deployment veterans and should be considered in etiology of complaints.

Predicting in-hospital mortality after traumatic brain injury: External validation of CRASH-basic and IMPACT-core in the national trauma data bank

BACKGROUND

Traumatic brain injury (TBI) prognostic prediction models offer value to individualized treatment planning, systematic outcome assessments and clinical research design but require continuous external validation to ensure generalizability to different settings. The Corticosteroid Randomization After Significant Head Injury (CRASH) and International Mission on Prognosis and Analysis on Clinical Trials in TBI (IMPACT) models are widely available but lack robust assessments of performance in a current national sample of patients. The purpose of this study is to assess the performance of the CRASH-Basic and IMPACT-Core models in predicting in-hospital mortality using a nationwide retrospective cohort from the National Trauma Data Bank (NTDB).

METHODS

The 2016 NTDB was used to analyze an adult cohort with moderate-severe TBI (Glasgow Coma Scale [GCS] ≤ 12, head Abbreviated Injury Scale of 2-6). Observed in-hospital mortality or discharge to hospice was compared to the CRASH-Basic and IMPACT-Core models' predicted probability of 14-day or 6-month mortality, respectively. Performance measures included discrimination (area under the receiver operating characteristic curve [AUC]) and calibration (calibration plots and Brier scores). Further sensitivity analysis included patients with GCS ≤ 14 and considered patients discharged to hospice to be alive at 14-days.

RESULTS

A total of 26,228 patients were included in this study. Both models demonstrated good ability in differentiating between patients who died and those who survived, with IMPACT demonstrating a marginally greater AUC (0.863; 95% CI: 0.858 - 0.867) than CRASH (0.858; 0.854 - 0.863); p < 0.001. On calibration, IMPACT overpredicted at lower scores and underpredicted at higher scores but had good calibration-in-the-large (indicating no systemic over/underprediction), while CRASH consistently underpredicted mortality. Brier scores were similar (0.152 for IMPACT, 0.162 for CRASH; p < 0.001). Both models showed slight improvement in performance when including patients with GCS ≤ 14.

CONCLUSION

Both CRASH-Basic and IMPACT-Core accurately predict in-hospital mortality following moderate-severe TBI, and IMPACT-Core performs well beyond its original GCS cut-off of 12, indicating potential utility for mild TBI (GCS 13-15). By demonstrating validity in the NTDB, these models appear generalizable to new data and offer value to current practice in diverse settings as well as to large-scale research design.

The effects of posttraumatic stress disorder symptoms on educational functioning in student veterans

Posttraumatic stress disorder (PTSD) occurs at high rates among student veterans and is known to negatively impact educational functioning; however, the unique effects of PTSD are less clear, given that PTSD is highly comorbid with many other conditions that could potentially affect educational functioning. The present study had two objectives: (a) to determine the impact of PTSD symptom severity on educational functioning after accounting for demographic variables, traumatic brain injury, and commonly co-occurring mental health conditions; and (b) to identify which symptom clusters of PTSD have the greatest impact on educational functioning. Educational functioning and other commonly occurring mental health conditions were assessed cross-sectionally among 90 student veterans. Traumatic brain injury and major depressive disorder (MDD) were initially associated with impaired educational functioning; however, after adding PTSD into the final model, only PTSD (β = .44, p < .001) and MDD (β = .31, p = .001) remained associated with educational impairment. Follow-up analyses indicated that the reexperiencing symptom cluster was most strongly associated with impaired educational functioning (β = .28, p = .031). Overall, these results suggest that PTSD symptoms-especially reexperiencing symptoms-may be a driving force behind impaired educational impairment, even after accounting for other commonly co-occurring mental health conditions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cognitive complaint and objective cognition during the post-acute period after mild traumatic brain injury in pre-morbidly healthy adults

Primary Objective:The most widely used proxies of cognitive complaint after mTBI are post-concussion syndrome (PCS) symptom checklists, which do not have a clear relationship with cognition. This study investigated whether an mTBI-specific cognitive complaint measure would have clearer associations with objective cognition than a widely used PCS symptom checklist.Research Design:An observational design was used. A sample of 109 participants (52 mTBI and 57 healthy controls) completed a PCS symptom checklist, a cognitive complaint measure, and measures of information processing speed, attention, memory, executive function, depression and anxiety.Main Outcomes and Results:In the healthy control group, cognitive complaint was significantly associated with objective cognitive performance and was not associated with psychological status. In contrast, PCS endorsement was unrelated to objective cognition but was associated with psychological status. For the mTBI group, neither PCS endorsement nor cognitive complaint was associated with cognitive performance, but both measures were associated with psychological status.Conclusions:This study indicates that neither cognitive nor PCS symptom measures are reliable indicators of underlying cognitive function in the post-acute period after mTBI. Further, suffering an mTBI may affect the linear relationship that exists between cognitive symptom endorsement and cognitive function in healthy adults.

Disentangling the effects of age and mild traumatic brain injury on brain network connectivity: A resting state fMRI study

INTRODUCTION

Cognitive complaints are common shortly after mild traumatic brain injury (mTBI) but may persist up to years. Age-related cognitive decline can worsen these symptoms. However, effects of age on mTBI sequelae have scarcely been investigated.

METHODS

Fifty-four mTBI patients (median age: 35 years, range 19-64 years, 67% male) and twenty age- and sex-matched healthy controls were studied using resting state functional magnetic resonance imaging in the sub-acute phase. Independent component analysis was used to identify intrinsic connectivity networks (ICNs). A multivariate approach was adopted to evaluate the effects of age and group on the ICNs in terms of (static) functional network connectivity (FNC), intensities of spatial maps (SMs) and time-course spectral power (TC).

RESULTS

We observed significant age-related changes for a) FNC: changes between 10 pairs of ICNs, mostly involving the default mode (DM) and/or the cognitive-control (CC) domains; b) SMs: intensity decrease in clusters across three domains and intensity increase in clusters across two domains, including the CC but not the DM and c) TC: spectral power decrease within the 0-0.15 Hz range and increase within the 0.20-0.25 Hz range for increasing age within networks located in frontal areas, including the anterior DM. Groups only differed for TC within the 0.065-0.10 Hz range in the cerebellar ICN and no age × group interaction effect was found.

CONCLUSIONS

We showed robust effects of age on connectivity between and within ICNs that are associated with cognitive functioning. Differences between mTBI patients and controls were only found for activity in the cerebellar network, increasingly recognized to participate in cognition. Our results suggest that to allow for capturing the true effects related to mTBI and its effects on cognitive functioning, age should be included as a covariate in mTBI studies, in addition to age-matching groups.

Neuromodulation for Mild Traumatic Brain Injury Rehabilitation: A Systematic Review

Background: Mild traumatic brain injury (mTBI) results from an external force to the head or body causing neurophysiological changes within the brain. The number and severity of symptoms can vary, with some individuals experiencing rapid recovery, and others having persistent symptoms for months to years, impacting their quality of life. Current rehabilitation is limited in its ability to treat persistent symptoms and novel approaches are being sought to improve outcomes following mTBI. Neuromodulation is one technique used to encourage adaptive neuroplasticity within the brain. Objective: To systematically review the literature on the efficacy of neuromodulation in the mTBI population. Method: A systematic review was conducted using Medline, Embase, PsycINFO, PsycARTICLES and EBM Review. Preferred Reporting Items for Systematic Reviews and the Synthesis Without Meta-analysis reporting guidelines were used and a narrative review of the selected studies was completed. Fourteen articles fulfilled the inclusion criteria which were published in English, investigating an adult sample and using a pre- and post-intervention design. Studies were excluded if they included non-mild TBI severities, pediatric or older adult populations. Results: Thirteen of fourteen studies reported positive reductions in mTBI symptomatology following neuromodulation. Specifically, improvements were reported in post-concussion symptom ratings, headaches, dizziness, depression, anxiety, sleep disturbance, general disability, cognition, return to work and quality of life. Normalization of working memory activation patterns, vestibular field potentials, hemodynamics of the dorsolateral prefrontal cortex and excessive delta wave activity were also seen. The studies reviewed had several methodological limitations including small, heterogenous samples and varied intervention protocols, limiting generalisability. Further research is required to understand the context in which neuromodulation may be beneficial. Conclusions: While these positive effects are observed, limitations included unequal representation of neuromodulation modalities in the literature, and lack of literature describing the efficacy of neuromodulation on the development or duration of persistent mTBI symptoms. Better clarity regarding neuromodulation efficacy could have a significant impact on mTBI patients, researchers, clinicians, and policy makers, facilitating a more productive post-mTBI population. Despite the limitations, the literature indicates that neuromodulation warrants further investigation. PROSPERO registration number: CRD42020161279.

Mitochondrial-Protective Effects of R-Phenibut after Experimental Traumatic Brain Injury

Altered neuronal Ca²⁺ homeostasis and mitochondrial dysfunction play a central role in the pathogenesis of traumatic brain injury (TBI). R-Phenibut ((3R)-phenyl-4-aminobutyric acid) is an antagonist of the α₂δ subunit of voltage-dependent calcium channels (VDCC) and an agonist of gamma-aminobutyric acid B (GABA-B) receptors. The aim of this study was to evaluate the potential therapeutic effects of R-phenibut following the lateral fluid percussion injury (latFPI) model of TBI in mice and the impact of R- and S-phenibut on mitochondrial functionality in vitro. By determining the bioavailability of R-phenibut in the mouse brain tissue and plasma, we found that R-phenibut (50 mg/kg) reached the brain tissue 15 min after intraperitoneal (i.p.) and peroral (p.o.) injections. The maximal concentration of R-phenibut in the brain tissues was 0.6 μg/g and 0.2 μg/g tissue after i.p. and p.o. administration, respectively. Male Swiss-Webster mice received i.p. injections of R-phenibut at doses of 10 or 50 mg/kg 2 h after TBI and then once daily for 7 days. R-Phenibut treatment at the dose of 50 mg/kg significantly ameliorated functional deficits after TBI on postinjury days 1, 4, and 7. Seven days after TBI, the number of Nissl-stained dark neurons (N-DNs) and interleukin-1beta (IL-1β) expression in the cerebral neocortex in the area of cortical impact were reduced. Moreover, the addition of R- and S-phenibut at a concentration of 0.5 μg/ml inhibited calcium-induced mitochondrial swelling in the brain homogenate and prevented anoxia-reoxygenation-induced increases in mitochondrial H₂O₂ production and the H₂O₂/O ratio. Taken together, these results suggest that R-phenibut could serve as a neuroprotective agent and promising drug candidate for treating TBI.

Symptom burden, validity, and cognitive performance in Iraq and Afghanistan veterans

INTRODUCTION

The present study evaluates the complex relationships between symptom burden, validity, and cognition in a sample of Iraq and Afghanistan veterans to identify key characteristic symptoms and validity measures driving cognitive performance. We hypothesized that symptom and performance validity would account for poorer outcomes on cognitive performance beyond psychological symptoms.

METHODS

Veterans (n = 226) completed a cognitive test battery, Personality Assessment Inventory (PAI), Word Memory Test (WMT), and Miller Forensic Assessment Symptom Test (M-FAST). Partial least squares structural equation modeling (PLS-SEM) modeled the fully-adjusted relationships among PAI subscales, validity, and cognitive performance.

RESULTS

23.45% of participants failed validity indices (19.9% WMT; 7.1% M-FAST). PLS-SEM indicated PAI subscales were not directly associated with performance or symptom validity measures, and there were no direct effects between validity performance and cognitive performance. Several PAI subscales were directly associated with measures of verbal abstraction, visual processing, and verbal learning and memory.

CONCLUSION

Contrary to hypotheses, symptom and performance validity did not account for poorer outcomes on cognitive performance beyond symptom burden in the PLS-SEM model. Results highlight the association between psychiatric symptoms and cognitive performance beyond validity status.

Prediction of Neurocognitive Outcome after Moderate-Severe Traumatic Brain Injury Using Serum Neuron-Specific Enolase and S100 biomarkers

Seric biomarkers have been tested in a large number of studies on traumatic brain injuries (TBI) patients in order to predict severity, especially related to the short-term outcome. However, TBI patients have a high risk of developing long-term complications such as physical disability, cognitive impairment, psychiatric pathology, epilepsy, and others. The aim of this study was to assess the correlation between protein biomarkers S100 and neuron-specific enolase (NSE) and neurocognitive status at 10- and 90-days post-injury. Both biomarkers were tested in the first 4h and after 72h post-injury in 62 patients with moderate-severe TBI. The patients were evaluated by a series of neurocognitive tests: Early Rehabilitation Barthel Index (ERBI), Glasgow Outcome Scale-Extended (GOSE), The Mini-Mental State Examination (MMSE), Processing Speed Index (PSI), and Stroop Test, at 10 and 90 days post-injury and supplementary by the Hospital Anxiety and Depression Scale at 90 days. For evaluating the whole neurocognitive status instead of every scale separately, we used Structural Equation Modeling (SEM), while for anxiety and depressive symptoms, we used multiple regression analyses. SEM showed that NSE values at 4 hours were significant predictors of the cognitive status at 10 (p=0.034) and 90 days (p= 0.023). Also, there were found significant correlations between NSE at 4h and the anxiety level. This study demonstrated a significant correlation between NSE at 4h and short and medium-term neuropsychological outcomes, which recommends using this biomarker for selecting patients with a higher risk of cognitive dysfunction.

Examining the Subacute Effects of Mild Traumatic Brain Injury Using a Traditional and Computerized Neuropsychological Test Battery

This study investigates subacute cognitive effects of mild traumatic brain injury (MTBI) in the Trondheim Mild TBI Study, as measured, in part, by the neuropsychological test battery of the Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) program, including computerized tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and traditional paper-and-pencil tests. We investigated whether cognitive function was associated with injury severity: intracranial traumatic lesions on neuroimaging, witnessed loss of consciousness (LOC), or post-traumatic amnesia (PTA) >1 h. Further, we explored which of the tests in the CENTER-TBI battery might be associated with the largest subacute effects of MTBI (i.e., at 2 weeks post-injury). We recruited 177 patients with MTBI (16-59 years of age) from a regional trauma center and an outpatient clinic,79 trauma control participants, and 81 community control participants. The MTBI group differed from community controls only on one traditional test of processing speed (coding; p = 0.009, Cliff's delta [Δ] = 0.20). Patients with intracranial abnormalities performed worse than those without on a traditional test (phonemic verbal fluency; p = 0.043, Δ = 0.27), and patients with LOC performed differently on the Attention Switching Task from the CANTAB (p = 0.020, Δ = -0.20). Patients with PTA >1 h performed worse than those with <1 h on 10 measures, from traditional tests and the CANTAB (Δ = 0.33-0.20), likely attributable, at least in part, to pre-existing differences in intellectual functioning between groups. In general, those with MTBI had good neuropsychological outcome 2 weeks after injury and no particular CENTER-TBI computerized or traditional tests seemed to be more sensitive to subtle cognitive deficits.

Promoting early treatment for mild traumatic brain injury in primary care with a guideline implementation tool: a pilot cluster randomised trial

OBJECTIVES

New clinical practice guidelines for the management of mild traumatic brain injury (mTBI) emphasise that family physicians should proactively screen and initiate treatment for depression/anxiety, insomnia and headaches. This study aimed to evaluate the feasibility of delivering an implementation intervention to family physicians.

DESIGN

Pilot cluster randomised controlled trial.

SETTING

Specialty outpatient clinic (recruitment) and primary care (implementation).

PARTICIPANTS

114 primary care clinics were randomised. These clinics were associated with 137 unique family physicians caring for 148 adult patients who sustained an mTBI within the previous 3 months and were seeking care for persistent symptoms.

INTERVENTIONS

Patients completed self-report screening measures for depression/anxiety, insomnia and headaches. A tailored letter that incorporates the patient's screening test results and associated treatment algorithms was sent to their family physician (or walk-in clinic). Physicians at clinics assigned to the control condition received a generic letter, without the screening test results.

PRIMARY OUTCOME MEASURES

Feasibility outcomes included the frequency of primary care follow-up, retention rates and reliability of patient recall of their physicians' actions (primary mechanistic outcome). The primary efficacy outcome was the Rivermead Post-Concussion Symptom Questionnaire (RPQ).

RESULTS

Most patients (97.8%; 128 of 131) followed up at the primary care clinic they planned to. Retention rates were 88% (131 of 148) and 78% (116 of 148) at the 1-month and 3-month assessments, respectively. Agreement between patient recall of their physicians' actions and medical chart audits was moderate (intraclass correlation coefficient=0.48-0.65). Patients in the experimental group reported fewer symptoms on the RPQ compared with those in the control group, whose physician received a general letter (B=-4.0, 95% CI: -7.3 to -0.7).

CONCLUSIONS

A larger trial will need to address minor feasibility challenges to evaluate the effectiveness of this guideline implementation tool for improving mTBI clinical outcomes and confirm the mechanism(s) of intervention benefit.

TRIAL REGISTRATION NUMBER

NCT03221218.

Therapeutic Effect of Aerobic Exercise for Adolescents After Mild Traumatic Brain Injury and Sport-Related Concussion: A Meta-Analysis from Randomized Controlled Trials

BACKGROUND

We searched PubMed, Embase, and the Cochrane Library for randomized controlled trials from January 1980 to April 2018 for adolescents with mild traumatic brain injury (mTBI) to explore the value of aerobic exercise in sport-related concussion (SRC) and mTBI treatment.

METHODS

A meta-analysis for the postconcussion symptom scale (PCSS) score and time to recovery was performed with STATA software.

RESULTS

We found that aerobic exercise versus usual treatment significantly decreased the PCSS score (weighted mean difference = 6.51, 95% confidence interval: 0.29, 12.72; P = 0.040), as well as the time to recovery (weighted mean difference = -3.87; 95% confidence interval: -6.50, -1.23; P = 0.004). However, aerobic exercise showed no significant improvement in immediate postconcussion assessment and cognitive testing (P = 0.471/0.129/0.648/0.800, respectively, in verbal memory, visual memory, visual motor speed, and reaction time).

CONCLUSIONS

Compared with usual treatment, aerobic exercise promoted mTBI adolescents' recovery, assessed by PCSS and time to recovery. However, aerobic exercise may not help with neurocognitive function recovery.

Functional cognitive disorder: dementia's blind spot

An increasing proportion of cognitive difficulties are recognized to have a functional cause, the chief clinical indicator of which is internal inconsistency. When these symptoms are impairing or distressing, and not better explained by other disorders, this can be conceptualized as a cognitive variant of functional neurological disorder, termed functional cognitive disorder (FCD). FCD is likely very common in clinical practice but may be under-diagnosed. Clinicians in many settings make liberal use of the descriptive term mild cognitive impairment (MCI) for those with cognitive difficulties not impairing enough to qualify as dementia. However, MCI is an aetiology-neutral description, which therefore includes patients with a wide range of underlying causes. Consequently, a proportion of MCI cases are due to non-neurodegenerative processes, including FCD. Indeed, significant numbers of patients diagnosed with MCI do not 'convert' to dementia. The lack of diagnostic specificity for MCI 'non-progressors' is a weakness inherent in framing MCI primarily within a deterministic neurodegenerative pathway. It is recognized that depression, anxiety and behavioural changes can represent a prodrome to neurodegeneration; empirical data are required to explore whether the same might hold for subsets of individuals with FCD. Clinicians and researchers can improve study efficacy and patient outcomes by viewing MCI as a descriptive term with a wide differential diagnosis, including potentially reversible components such as FCD. We present a preliminary definition of functional neurological disorder-cognitive subtype, explain its position in relation to other cognitive diagnoses and emerging biomarkers, highlight clinical features that can lead to positive diagnosis (as opposed to a diagnosis of exclusion), and red flags that should prompt consideration of alternative diagnoses. In the research setting, positive identifiers of FCD will enhance our recognition of individuals who are not in a neurodegenerative prodrome, while greater use of this diagnosis in clinical practice will facilitate personalized interventions.

Early Life Stress Exacerbates Outcome after Traumatic Brain Injury

The neurocognitive impairments associated with mild traumatic brain injury (TBI) often resolve within 1-2 weeks; however, a subset of people exhibit persistent cognitive dysfunction for weeks to months after injury. The factors that contribute to these persistent deficits are unknown. One potential risk factor for worsened outcome after TBI is a history of stress experienced by a person early in life. Early life stress (ELS) includes maltreatment such as neglect, and interferes with the normal construction of cortical and hippocampal circuits. We hypothesized that a history of ELS contributes to persistent learning and memory dysfunction following a TBI. To explore this interaction, we modeled ELS by separating Sprague Dawley pups from their nursing mothers from post-natal days 2-14 for 3 h daily. At 2 months of age, male rats received sham surgery or mild to moderate parasagittal fluid-percussion brain injury. We found that the combination of ELS with TBI in adulthood impaired hippocampal-dependent learning, as assessed with contextual fear conditioning, the water maze task, and spatial working memory. Cortical atrophy was significantly exacerbated in TBI animals exposed to ELS compared with normal-reared TBI animals. Changes in corticosterone in response to restraint stress were prolonged in TBI animals that received ELS compared with TBI animals that were normally reared or sham animals that received ELS. Our findings indicate that ELS is a risk factor for worsened outcome after TBI, and results in persistent learning and memory deficits, worsened cortical pathology, and an exacerbation of the hormonal stress response.

Persistent Postconcussion Symptoms: An Expert Consensus-Based Definition Using the Delphi Method

OBJECTIVE

To provide an expert consensus definition of persistent postconcussion symptoms following a mild traumatic brain injury (mTBI).

PARTICIPANTS

Canadian healthcare professionals caring for patients with mTBI.

DESIGN

Online Delphi process.

MAIN MEASURES

A first Delphi round documented important dimensions or criteria to consider when defining persistent symptoms. Expert opinions were then resubmitted in 4 subsequent Delphi rounds and their relevance was rated using a 9-point Likert scale. An item with a median rating of 7 or more and a sufficient level of agreement were considered consensual.

RESULTS

After 5 rounds, consensus was reached on a set of criteria that can be summarized as follows: presence of any symptom that cannot be attributed to a preexisting condition and that appeared within hours of an mTBI, that is still present every day 3 months after the trauma, and that has an impact on at least one sphere of a person's life.

CONCLUSION

This Delphi consensus proposes a set of criteria that support a more uniform definition of persistent symptoms in mild TBI among clinicians and researchers. This definition may help clinicians better identify persistent postconcussion symptoms and improve patient management.

Development and description of SAAM intervention: A brief, multidimensional and psycho-educational intervention for adults with mild traumatic brain injury

BACKGROUND

Mild traumatic brain injury (mTBI) is associated with persistent post-concussive symptoms (PCSs) in approximately 15% of cases. These symptoms can be somatic (e.g., headache), cognitive (e.g., forgetfulness, poor attention and concentration capacities), emotional (e.g., anxiety, depression, irritability) and/or sleep-arousal complaints (e.g., fatigue, sleep problems). Although practice guidelines recommend early intervention to prevent and treat PCS, we still lack an effective, standardized, integrative, post-acute intervention based on a sound and validated theoretical model.

OBJECTIVES

The purpose of this article is to present the development and theoretical background underpinning a novel intervention for patients with PCSs in the post-acute phase after mTBI (1-3 months post-injury).

PROCEDURE

With a biopsychosocial approach (Hou et al., 2012) and best practice recommendations, we developed a novel multidimensional intervention targeting factors that perpetuate PCSs and that can be changed with the intervention. This individual-session intervention provides practical tools for managing PCSs and is designed to provide psycho-education and reassurance, reinforce individual objectives and promote a return to activities. Each session targets one category of PCSs: Sleep/fatigue, Attention, Anxiety/depressed mood, Memory/Organization (SAAM intervention). The rationale underlying the choices of format and content for the intervention is discussed, as are the associated strengths, limitations, opportunities and challenges.

CONCLUSION

This article could support researchers and clinicians to develop, replicate and/or implement interventions addressing current best practices in mTBI management.