Post-Traumatic Stress Disorder After Traumatic Brain Injury-A Systematic Review and Meta-Analysis

Clinical relevance of subthreshold PTSD versus full criteria PTSD following traumatic brain injury in U.S. service members and veterans

BACKGROUND

The purpose of this cross-sectional study was to examine the influence of subthreshold posttraumatic stress disorder (PTSD) and full PTSD on quality of life following mild traumatic brain injury (mTBI).

METHODS

Participants were 734 service members and veterans (SMV) classified into two injury groups: uncomplicated mild TBI (MTBI; n = 596) and injured controls (IC, n = 139). Participants completed a battery of neurobehavioral measures, 12-or-more months post-injury, that included the PTSD Checklist Civilian version, Neurobehavioral Symptom Inventory, and select scales from the TBI-QOL and MPAI. The MTBI group was divided into three PTSD subgroups: No-PTSD (n = 266), Subthreshold PTSD (n = 139), and Full-PTSD (n = 190).

RESULTS

There was a linear relationship between PTSD severity and neurobehavioral functioning/quality of life in the MTBI sample. As PTSD severity increased, significantly worse scores were found on 11 of the 12 measures (i.e.

, MTBI

Full-PTSD > Sub-PTSD > No-PTSD). When considering the number of clinically elevated scores, a linear relationship between PTSD severity and neurobehavioral functioning/quality of life was again observed in the MTBI sample (e.g., 3-or-more elevated scores: Full-PTSD = 92.1 %, Sub-PTSD = 61.9 %, No-PTSD = 19.9 %).

LIMITATIONS

Limitations included the use of a self-report measure to determine diagnostic status that may under/overcount or mischaracterize individuals.

CONCLUSION

PTSD symptoms, whether at the level of diagnosable PTSD, or falling short of that because of the intensity or characterization of symptoms, have a significant negative impact on one's quality of life following MTBI. Clinicians' treatment targets should focus on the symptoms that are most troubling for an individual and the individual's perception of quality of life, regardless of the diagnosis itself.

Prevalence of PTSD in Active Duty Members with Mild Traumatic Brain Injury: Systematic Review and Meta-analysis

INTRODUCTION

Traumatic brain injury (TBI), particularly mild TBI (mTBI), is a significant health concern for U.S. active duty service members (ADSMs), with potential implications for psychiatric outcomes including PTSD. Despite recognizing this association, the prevalence of PTSD among ADSMs with mTBI remains unclear.

MATERIALS AND METHODS

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A thorough search in PubMed, CINAHL, Embase, and PsycINFO databases from 2008 to 2024 focused on identifying studies involving ADSMs with PTSD and mTBI. The R software (version 4.3.2) was employed for meta-analysis with the "meta" and "meta prop" packages.

RESULTS

Eight reviewed studies revealed a pooled prevalence estimate of PTSD among ADSMs with mTBI at 36% (95% CI, 30%-41%, P < .01, I2 = 96%). Cohort studies indicated a slightly higher prevalence of 38% (95% CI, 19%-59%, P < .01, I2 = 98%), whereas cross-sectional studies provided a marginally lower prevalence of 34% (95% CI, 27%-40%, P < .01, I2 = 92%).

CONCLUSION

Methodological differences, including diagnostic criteria variability, contribute to the observed variability in prevalence estimates. Despite methodological challenges, this study provides crucial insights into the pooled prevalence of comorbid PTSD and mTBI within the military, emphasizing the need for standardized methodologies and further research to refine understanding and support strategies for affected individuals.

Diagnostic Accuracy of Mental Health Screening Tools After Mild Traumatic Brain Injury

Importance

Mental health disorders are common after mild traumatic brain injury (mTBI) and likely exacerbate postconcussive symptoms and disability. Early detection could improve clinical outcomes, but the accuracy of mental health screening tools in this population has not been well established.

Objective

To determine the diagnostic accuracy of the Patient Health Questionnaire-9 (PHQ-9), Generalizaed Anxiety Disorder-7 (GAD-7), and Primary Care PTSD (Posttramatic Stress Disorder) Screen for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5) (PC-PTSD-5) in adults with mTBI.

Design, Setting, and Participants

This diagnostic study was performed as a secondary analysis of a cluster randomized clinical trial. Self-report mental health screening tools (PHQ-9, GAD-7, and PC-PTSD-5) were administered online 12 weeks after mTBI and compared against a structured psychodiagnostic interview (Mini-International Neuropsychiatric Interview for DSM-5 (MINI) over videoconference at the same time. Adults with mTBI (N = 537) were recruited from February 1, 2021, to October 25, 2022.

Main Outcomes and Measures

Presence of a major depressive episode, anxiety disorders, and PTSD were determined by a blinded assessor with the MINI. Diagnostic accuracy statistics were derived for the PHQ-9, GAD-7, and PC-PTSD-5. Findings were disaggregated for participants with and without persistent postconcussion symptoms (PPCS) by International and Statistical Classification of Diseases, Tenth Revision criteria.

Results

Data were available for 499 of 537 trial participants, 278 (55.7%) of whom were female; the mean (SD) age was 38.8 (13.9) years. Each screening questionnaire had strong diagnostic accuracy in the overall sample for optimal cut points (area under the curve [AUC], ≥0.80; sensitivity, 0.55-0.94; specificity, 0.64-0.94). The AUC (difference of 0.01-0.13) and specificity (difference, 5-65 percentage points) were lower in those with PPCS present compared with PPCS absent, but the prevalence of at least 1 mental health disorder was 3 to 5 times higher in patients with PPCS present. The GAD-7 had slightly better performance than the PC-PTSD-5 for detecting PTSD (AUC, 0.85 [95% CI, 0.80-0.89] vs 0.80 [95% CI, 0.72-0.87]). The optimal cutoff on the PHQ-9 was 5 or more symptoms experienced on more than half of days; on the GAD-7, a total score of at least 7.

Conclusions and Relevance

The findings of this diagnostic study suggest that the PHQ-9, GAD-7 and PC-PTSD-5 accurately screen for mental health disorders in patients with mTBI. Future research should corroborate optimal test cutoffs for this population.

Gender Disparities in Neurobehavioral Symptoms and the Role of Post-Traumatic Symptoms in US Service Members Following Mild Traumatic Brain Injury

Women are more directly involved in combat operations today than ever before, currently making up 18.6% of officers and 16.8% of enlisted personnel in the United States military. However, women continue to be under-represented in military research. Studies that do consider gender differences in traumatic brain injury (TBI) outcomes have shown that women report significantly more post-concussive symptoms than men. Conclusions for true gender differences related to TBI are hard to make without controlling for non-TBI factors. The effects previously identified in the literature may be an artifact of how men and women differ in their response to injury, unrelated to the neurological recovery process associated with TBI. The objective of this study was to examine the effects of gender specifics on mild TBI (mTBI) sequelae on injured and uninjured control groups, and to investigate the role of post-traumatic stress disorder (PTSD) on symptom reporting. It should be noted that the terms "gender" and "men/women" are used in this article in place of "sex" or "males/females" given that we are not discussing biological attributes. A total of 966 United States military service members and veterans were included in the study. Of the total sample, 455 men and 46 women were in the mTBI group, 285 men and 31 women were in the injured controls group (IC), and 111 men and 38 women in the non-injured controls group (NIC). Post-concussive and quality of life symptoms were compared for men and women while controlling for combat exposure. MTBI and IC groups were also stratified by PTSD presentation. Measures used included the Neurobehavioral Symptom Inventory (NSI), PTSD Checklist (PCL-C), Traumatic Brain Injury Quality of Life (TBI-QOL), and Combat Exposure Scale. In the mTBI group, women had worse scores on NSI total, NSI Somatosensory and Affective clusters, and the TBI-QOL Anxiety, Fatigue, and Headache scales (n2 = 0.018-0.032, small to small-medium effect sizes). When PTSD was present, women had worse scores on the NSI Somatosensory cluster only (n2 = 0.029, small-medium effect size). In contrast, when PTSD was absent, women had worse scores than men on the NSI Somatosensory and Affective clusters, and the TBI-QOL Anxiety and Headache scales (n2 = 0.032-0.063, small to medium effect sizes). In the IC group, women had worse scores on the NSI Cognitive cluster and the TBI-QOL Fatigue and Pain Interference scales (n2 = 0.024-0.042, small to small-medium effect sizes). However, group differences were no longer found when stratified by PTSD sub-groups. In the NIC group, there were no significant group differences for any analyses. We were able to identify symptoms unique to women recovering from mTBI that were not present following other forms of physical injury or in healthy controls. However, the impact of PTSD exacerbates the symptom profile and its comorbidity with mTBI equates to most of the noted gender differences.

The Frequency of Neuropsychiatric Sequelae After Traumatic Brain Injury in the Global South: A systematic review and meta-analysis

This study aimed to assess the prevalence of neuropsychiatric sequelae following traumatic brain injury (TBI) among the Western Asian, South Asian and African regions of the global south. All studies on psychiatric disturbances or cognitive impairment following TBI conducted (until August 2021) in the 83 countries that constitute the aforementioned regions were reviewed; 6 databases were selected for the literature search. After evaluating the articles using the Joanna Briggs Institute guidelines, the random effects model was used to estimate the prevalence of depression, anxiety, post-traumatic stress disorder (PTSD), TBI-related sleep disturbance (TBI-SD), obsessive-compulsive disorder (OCD) and cognitive impairment. Of 56 non-duplicated studies identified in the initial search, 27 were eligible for systematic review and 23 for meta-analysis. The pooled prevalence of depression in 1,882 samples was 35.35%, that of anxiety in 1,211 samples was 28.64%, that of PTSD in 426 samples was 19.94%, that of OCD in 313 samples was 19.48%, that of TBI-SD in 562 samples was 26.67% and that of cognitive impairment in 941 samples was 49.10%. To date, this is the first critical review to examine the spectrum of post-TBI neuropsychiatric sequelae in the specified regions. Although existing studies lack homogeneous data due to variability in the diagnostic tools and outcome measures utilised, the reported prevalence rates are significant and comparable to statistics from the global north.

Work-related and non-work-related mild traumatic brain injury: Associations with mental health and substance use challenges in a Canadian population-level survey

BACKGROUND

Mild traumatic brain injury (mTBI) can profoundly impact overall health, employment, and family life. Incidence of mTBI in the workplace represents an important subgroup with poorer outcomes. Mental health (MH) and substance use (SU) challenges are a primary correlate of TBI, but are rarely assessed among individuals with a work-related (wr)-mTBI, particularly at a population-level.

OBJECTIVE

This study aimed to assess the association between lifetime wr-mTBI and non-wr-mTBI and the experience of MH and SU challenges.

METHODS

The 2019 Centre for Addiction and Mental Health (CAMH) Monitor is a cross-sectional telephone survey of adults aged≥18 years in Ontario, Canada, employing a stratified (six regions) two-stage (telephone number, respondent) list-assisted random digit dialing probability selection procedure (N = 1792). Adjusting for sociodemographic variables, binary logistic regression was conducted to assess the association between lifetime wr-mTBI and non-wr-mTBI (relative to no TBI) and four outcomes: hazardous use of alcohol and of cannabis, psychological distress, and fair/poor mental health.

RESULTS

Adjusting for sociodemographic variables, non-wr-mTBI demonstrated increased odds of hazardous alcohol (AOR = 2.12, 95% CI = 1.41, 3.19) and cannabis use (AOR = 1.61, 95% CI = 1.05, 2.45), psychological distress (AOR = 1.68, 95% CI = 1.14, 2.49), and fair/poor mental health (AOR = 1.70, 95% CI = 1.11, 2.59). Lifetime wr-mTBI demonstrated increased odds of reporting psychological distress (AOR = 3.40, 95% CI = 1.93, 5.97) and fair/poor mental health (AOR = 2.16, 95% CI = 1.12, 4.19) only.

CONCLUSIONS

Non-wr-mTBI was associated with both MH and SU, whereas wr-mTBI was associated with MH only. MH outcomes were more strongly associated with wr-mTBI than non-wr-mTBI. Physicians, employers, and insurers need to consider the potential association between wr-mTBI and MH, and provide care accordingly.

Brain FADE syndrome: the final common pathway of chronic inflammation in neurological disease

Importance

While the understanding of inflammation in the pathogenesis of many neurological diseases is now accepted, this special commentary addresses the need to study chronic inflammation in the propagation of cognitive Fog, Asthenia, and Depression Related to Inflammation which we name Brain FADE syndrome. Patients with Brain FADE syndrome fall in the void between neurology and psychiatry because the depression, fatigue, and fog seen in these patients are not idiopathic, but instead due to organic, inflammation involved in neurological disease initiation.

Observations

A review of randomized clinical trials in stroke, multiple sclerosis, Parkinson's disease, COVID, traumatic brain injury, and Alzheimer's disease reveal a paucity of studies with any component of Brain FADE syndrome as a primary endpoint. Furthermore, despite the relatively well-accepted notion that inflammation is a critical driving factor in these disease pathologies, none have connected chronic inflammation to depression, fatigue, or fog despite over half of the patients suffering from them.

Conclusions and relevance

Brain FADE Syndrome is important and prevalent in the neurological diseases we examined. Classical "psychiatric medications" are insufficient to address Brain FADE Syndrome and a novel approach that utilizes sequential targeting of innate and adaptive immune responses should be studied.

Frontotemporal disorders: the expansive panoply of syndromes and spectrum of etiologies

Background

Frontotemporal lobe disorders (FTD) are amongst the most common brain neurodegenerative disorders. Their relatively covert, frequently subtle presentations and diverse etiologies, pose major challenges in diagnosis and treatments. Recent studies have yielded insights that the etiology in the majority are due to environmental and sporadic causes, rather than genetic in origin.

Aims

To retrospectively examine the cognitive and behavioral impairments in the veteran population to garner the range of differing syndrome presentations and etiological subcategories with a specific focus on frontotemporal lobe disorders.

Methodology

The design is a retrospective, observational registry, case series with the collection of epidemiological, clinical, cognitive, laboratory and radiological data on people with cognitive and behavioral disorders. Inclusion criteria for entry were veterans evaluated exclusively at Orlando VA Healthcare System, neurology section, receiving a diagnosis of FTD by standard criteria, during the observation period dated from July 2016 to March 2021. Frontotemporal disorders (FTD) were delineated into five clinical 5 subtypes. Demographic, cardiovascular risk factors, cognitive, behavioral neurological, neuroimaging data and presumed etiological categories, were collected for those with a diagnosis of frontotemporal disorder.

Results

Of the 200 patients with FTD, further cognitive, behavioral neurological evaluation with standardized, metric testing was possible in 105 patients. Analysis of the etiological groups revealed significantly different younger age of the traumatic brain injury (TBI) and Gulf War Illness (GWI) veterans who also had higher Montreal Cognitive Assessment (MOCA) scores. The TBI group also had significantly more abnormalities of hypometabolism, noted on the PET brain scans. Behavioral neurological testing was notable for the findings that once a frontotemporal disorder had been diagnosed, the four different etiological groups consistently had abnormal FRSBE scores for the 3 principal frontal presentations of (i) abulia/apathy, (ii) disinhibition, and (iii) executive dysfunction as well as abnormal Frontal Behavioral Inventory (FBI) scores with no significant difference amongst the etiological groups. The most common sub-syndromes associated with frontotemporal syndromes were the Geschwind-Gastaut syndrome (GGS), Klüver-Bucy syndrome (KBS), involuntary emotional expression disorder (IEED), cerebellar cognitive affective syndrome (CCA), traumatic encephalopathy syndrome (TES) and prosopagnosia. Comparisons with the three principal frontal lobe syndrome clusters (abulia, disinhibition, executive dysfunction) revealed a significant association with abnormal disinhibition FRSBE T-scores with the GGS. The regression analysis supported the potential contribution of disinhibition behavior that related to this complex, relatively common behavioral syndrome in this series. The less common subsyndromes in particular, were notable, as they constituted the initial overriding, presenting symptoms and syndromes characterized into 16 separate conditions.

Conclusion

By deconstructing FTD into the multiple sub-syndromes and differing etiologies, this study may provide foundational insights, enabling a more targeted precision medicine approach for future studies, both in treating the sub-syndromes as well as the underlying etiological process.

Synaptamide Ameliorates Hippocampal Neurodegeneration and Glial Activation in Mice with Traumatic Brain Injury

Traumatic brain injury (TBI) is a major concern for public health worldwide, affecting 55 million people and being the leading cause of death and disability. To improve the outcomes and effectiveness of treatment for these patients, we conducted a study on the potential therapeutic use of N-docosahexaenoylethanolamine (synaptamide) in mice using the weight-drop injury (WDI) TBI model. Our study focused on exploring synaptamide's effects on neurodegeneration processes and changes in neuronal and glial plasticity. Our findings showed that synaptamide could prevent TBI-associated working memory decline and neurodegenerative changes in the hippocampus, and it could alleviate decreased adult hippocampal neurogenesis. Furthermore, synaptamide regulated the production of astro- and microglial markers during TBI, promoting the anti-inflammatory transformation of the microglial phenotype. Additional effects of synaptamide in TBI include stimulating antioxidant and antiapoptotic defense, leading to the downregulation of the Bad pro-apoptotic marker. Our data suggest that synaptamide has promising potential as a therapeutic agent to prevent the long-term neurodegenerative consequences of TBI and improve the quality of life.

Effect of Dexmedetomidine on Posttraumatic Stress Disorder in Patients Undergoing Emergency Trauma Surgery: A Randomized Clinical Trial

Importance

Posttraumatic stress disorder (PTSD) is common in people who have experienced trauma, especially those hospitalized for surgery. Dexmedetomidine may reduce or reverse the early consolidation and formation of conditioned fear memory and prevent the occurrence of postoperative PTSD.

Objective

To evaluate the effects of intraoperative and postoperative low-dose intravenous pumping dexmedetomidine on PTSD among patients with trauma undergoing emergency surgery.

Design, Setting, and Participants

This double-blind, randomized clinical trial was conducted from January 22 to October 20, 2022, with follow-up 1 month postoperatively, in patients with trauma undergoing emergency surgery at 4 hospital centers in Jiangsu Province, China. A total of 477 participants were screened. The observers were blinded to patient groupings, particularly for subjective measurements.

Interventions

Dexmedetomidine or placebo (normal saline) was administered at a maintenance dose of 0.1 μg/kg hourly from the start of anesthesia until the end of surgery and at the same rate after surgery from 9 pm to 7 am on days 1 to 3.

Main Outcomes and Measures

The primary outcome was the difference in the incidence of PTSD 1 month after surgery in the 2 groups. This outcome was assessed with the Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (CAPS-5). The secondary outcomes were the pain score within 48 hours and 1 month postoperatively; incidence of postoperative delirium, nausea, and pruritus; subjective sleep quality; anxiety; and occurrence of adverse events.

Results

A total of 310 patients (154 in the normal saline group and 156 in the dexmedetomidine group) were included in the modified intention-to-treat analysis (mean [SD] age, 40.2 [10.3] years; 179 men [57.7%]). The incidence of PTSD was significantly lower in the dexmedetomidine group than in the control group 1 month postoperatively (14.1% vs 24.0%; P = .03). The participants in the dexmedetomidine group had a significantly lower CAPS-5 score than those in the control group (17.3 [5.3] vs 18.9 [6.6]; mean difference, 1.65; 95% CI, 0.31-2.99; P = .02). After adjusting for potential confounders, the patients in the dexmedetomidine group were less likely to develop PTSD than those in the control group 1 month postoperatively (adjusted odds ratio, 0.51; 95% CI, 0.27-0.94; P = .03).

Conclusions and Relevance

In this randomized clinical trial, the administration of intraoperative and postoperative dexmedetomidine reduced the incidence of PTSD among patients with trauma. The findings of this trial support the use of dexmedetomidine in emergency trauma surgery.

Trial Registration

Chinese Clinical Trial Register Identifier: ChiCTR2200056162.

Disturbances in fear extinction learning after mild traumatic brain injury in mice are accompanied by alterations in dendritic plasticity in the medial prefrontal cortex and basolateral nucleus of the amygdala

Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) have emerged as the signature injuries of the U.S. veterans who served in Iraq and Afghanistan, and frequently co-occur in both military and civilian and populations. To better understand how fear learning and underlying neural systems might be altered after mTBI we examined the acquisition of cued fear conditioning and its extinction along with brain morphology and dendritic plasticity in a mouse model of mTBI. To induce mTBI in adult male C57BL/6J mice, a lateral fluid percussive injury (LFP 1.7) was produced using a fluid pulse of 1.7 atmosphere force to the right parietal lobe. Behavior in LFP 1.7 mice was compared to behavior in mice from two separate control groups: mice subjected to craniotomy without LFP injury (Sham) and mice that did not undergo surgery (Unoperated). Following behavioral testing, neural endpoints (dendritic structural plasticity and neuronal volume) were assessed in the basolateral nucleus of the amygdala (BLA), which plays a critical sensory role in fear learning, and medial prefrontal cortex (mPFC), responsible for executive functions and inhibition of fear behaviors. No gross motor abnormalities or increased anxiety-like behaviors were observed in LFP or Sham mice after surgery compared to Unoperated mice. We found that all mice acquired fear behavior, assessed as conditioned freezing to auditory cue in a single session of 6 trials, and acquisition was similar across treatment groups. Using a linear mixed effects analysis, we showed that fear behavior decreased overall over 6 days of extinction training with no effect of treatment group across extinction days. However, a significant interaction was demonstrated between the treatment groups during within-session freezing behavior (5 trials per day) during extinction training. Specifically, freezing behavior increased across within-session extinction trials in LFP 1.7 mice, whereas freezing behavior in control groups did not change on extinction test days, reflecting a dissociation between within-trial and between-trial fear extinction. Additionally, LFP mice demonstrated bilateral increases in dendritic spine density in the BLA and decreases in dendritic complexity in the PFC. The translational implications are that individuals with TBI undergoing fear extinction therapy may demonstrate within-session aberrant learning that could be targeted for more effective treatment interventions.

Headache comorbidity in refugees and migrants with post-traumatic stress disorder

BACKGROUND

Headache is often comorbid with post-traumatic stress disorder yet overlooked in health assessments of refugees.

OBJECTIVES

To describe prevalence of severe headache among refugees with post-traumatic stress disorder and compare severity of post-traumatic stress disorder symptoms and treatment outcomes among those with and without severe headache.

METHODS

This follow-up study used data from the Danish Database on Refugees with Trauma. Participants were recruited from 2009 to 2015 at a specialized psychiatric clinic. Prevalence of severe headache was computed by age, sex, and history of head injury or torture. Severe headache was defined as maximum headache scores on the Hopkins Symptom Checklist, Symptom Checklist-90 or the Visual Analogue Scale. Groups with and without severe headache were described according to validated questionnaires before and after 12-18 months of multidisciplinary treatment for post-traumatic stress disorder. Regression analyses were used to analyze associations between headache at start of treatment and symptom burden post-treatment, controlled for pre-treatment scores and possible confounders.

RESULTS

Among 403 female and 489 male participants, nearly all (97.5%) complained of headaches. Severe headache prevalence was 31.4% to 50.0% (depending on which questionnaire was used) and was significantly more common among females and those aged 30-49 years. There was no clear relationship between headache and head injury or torture. Participants with severe headache had heavier symptom burdens compared to those without severe headache. Post-treatment, headache prevalence by age and sex did not change significantly. Those without severe headache showed a tendency toward improvement in outcome measures; this was not seen among those with severe headache. Pre-treatment headache scores were correlated with all outcome measures. Regression analyses controlled for pre-treatment scores of the outcome variables showed associations between pre-treatment headache scores (Hopkins Symptom Checklist or Symptom Checklist-90) and post-treatment scores for intrusion, numbing, hyperarousal, anxiety, disability, and quality of life (all p < 0.02).

CONCLUSION

Headache is a prevalent comorbid condition among refugees with post-traumatic stress disorder. Measures of pre-treatment headache severity appear to predict post-traumatic stress disorder treatment outcomes. Severe headache adversely affects post-traumatic stress disorder prognosis. Assessment and treatment options should be studied further.

Management of Psychological Complications Following Mild Traumatic Brain Injury

PURPOSE OF REVIEW

It has been clear for decades that psychological factors often contribute to mild traumatic brain injury (mTBI) outcome, but an emerging literature has begun to clarify which specific factors are important, when, for whom, and how they impact recovery. This review aims to summarize the contemporary evidence on psychological determinants of recovery from mTBI and its implications for clinical management.

RECENT FINDINGS

Comorbid mental health disorders and specific illness beliefs and coping behaviors (e.g., fear avoidance) are associated with worse recovery from mTBI. Proactive assessment and intervention for psychological complications can improve clinical outcomes. Evidence-based treatments for primary mental health disorders are likely also effective for treating mental health disorders after mTBI, and can reduce overall post-concussion symptoms. Broad-spectrum cognitive-behavioral therapy may modestly improve post-concussion symptoms, but tailoring delivery to individual psychological risk factors and/or symptoms may improve its efficacy. Addressing psychological factors in treatments delivered primarily by non-psychologists is a promising and cost-effective approach for enhancing clinical management of mTBI. Recent literature emphasizes a bio-psycho-socio-ecological framework for understanding mTBI recovery and a precision rehabilitation approach to maximize recovery. Integrating psychological principles into rehabilitation and tailoring interventions to specific risk factors may improve clinical management of mTBI.

Traumatic brain injury: progress and challenges in prevention, clinical care, and research

Traumatic brain injury (TBI) has the highest incidence of all common neurological disorders, and poses a substantial public health burden. TBI is increasingly documented not only as an acute condition but also as a chronic disease with long-term consequences, including an increased risk of late-onset neurodegeneration. The first Lancet Neurology Commission on TBI, published in 2017, called for a concerted effort to tackle the global health problem posed by TBI. Since then, funding agencies have supported research both in high-income countries (HICs) and in low-income and middle-income countries (LMICs). In November 2020, the World Health Assembly, the decision-making body of WHO, passed resolution WHA73.10 for global actions on epilepsy and other neurological disorders, and WHO launched the Decade for Action on Road Safety plan in 2021. New knowledge has been generated by large observational studies, including those conducted under the umbrella of the International Traumatic Brain Injury Research (InTBIR) initiative, established as a collaboration of funding agencies in 2011. InTBIR has also provided a huge stimulus to collaborative research in TBI and has facilitated participation of global partners. The return on investment has been high, but many needs of patients with TBI remain unaddressed. This update to the 2017 Commission presents advances and discusses persisting and new challenges in prevention, clinical care, and research.

In LMICs, the occurrence of TBI is driven by road traffic incidents, often involving vulnerable road users such as motorcyclists and pedestrians. In HICs, most TBI is caused by falls, particularly in older people (aged ≥65 years), who often have comorbidities. Risk factors such as frailty and alcohol misuse provide opportunities for targeted prevention actions. Little evidence exists to inform treatment of older patients, who have been commonly excluded from past clinical trials—consequently, appropriate evidence is urgently required. Although increasing age is associated with worse outcomes from TBI, age should not dictate limitations in therapy. However, patients injured by low-energy falls (who are mostly older people) are about 50% less likely to receive critical care or emergency interventions, compared with those injured by high-energy mechanisms, such as road traffic incidents.

Mild TBI, defined as a Glasgow Coma sum score of 13–15, comprises most of the TBI cases (over 90%) presenting to hospital. Around 50% of adult patients with mild TBI presenting to hospital do not recover to pre-TBI levels of health by 6 months after their injury. Fewer than 10% of patients discharged after presenting to an emergency department for TBI in Europe currently receive follow-up. Structured follow-up after mild TBI should be considered good practice, and urgent research is needed to identify which patients with mild TBI are at risk for incomplete recovery.

The selection of patients for CT is an important triage decision in mild TBI since it allows early identification of lesions that can trigger hospital admission or life-saving surgery. Current decision making for deciding on CT is inefficient, with 90–95% of scanned patients showing no intracranial injury but being subjected to radiation risks. InTBIR studies have shown that measurement of blood-based biomarkers adds value to previously proposed clinical decision rules, holding the potential to improve efficiency while reducing radiation exposure. Increased concentrations of biomarkers in the blood of patients with a normal presentation CT scan suggest structural brain damage, which is seen on MR scanning in up to 30% of patients with mild TBI. Advanced MRI, including diffusion tensor imaging and volumetric analyses, can identify additional injuries not detectable by visual inspection of standard clinical MR images. Thus, the absence of CT abnormalities does not exclude structural damage—an observation relevant to litigation procedures, to management of mild TBI, and when CT scans are insufficient to explain the severity of the clinical condition.

Although blood-based protein biomarkers have been shown to have important roles in the evaluation of TBI, most available assays are for research use only. To date, there is only one vendor of such assays with regulatory clearance in Europe and the USA with an indication to rule out the need for CT imaging for patients with suspected TBI. Regulatory clearance is provided for a combination of biomarkers, although evidence is accumulating that a single biomarker can perform as well as a combination. Additional biomarkers and more clinical-use platforms are on the horizon, but cross-platform harmonisation of results is needed. Health-care efficiency would benefit from diversity in providers.

In the intensive care setting, automated analysis of blood pressure and intracranial pressure with calculation of derived parameters can help individualise management of TBI. Interest in the identification of subgroups of patients who might benefit more from some specific therapeutic approaches than others represents a welcome shift towards precision medicine. Comparative-effectiveness research to identify best practice has delivered on expectations for providing evidence in support of best practices, both in adult and paediatric patients with TBI.

Progress has also been made in improving outcome assessment after TBI. Key instruments have been translated into up to 20 languages and linguistically validated, and are now internationally available for clinical and research use. TBI affects multiple domains of functioning, and outcomes are affected by personal characteristics and life-course events, consistent with a multifactorial bio-psycho-socio-ecological model of TBI, as presented in the US National Academies of Sciences, Engineering, and Medicine (NASEM) 2022 report. Multidimensional assessment is desirable and might be best based on measurement of global functional impairment. More work is required to develop and implement recommendations for multidimensional assessment. Prediction of outcome is relevant to patients and their families, and can facilitate the benchmarking of quality of care. InTBIR studies have identified new building blocks (eg, blood biomarkers and quantitative CT analysis) to refine existing prognostic models. Further improvement in prognostication could come from MRI, genetics, and the integration of dynamic changes in patient status after presentation.

Neurotrauma researchers traditionally seek translation of their research findings through publications, clinical guidelines, and industry collaborations. However, to effectively impact clinical care and outcome, interactions are also needed with research funders, regulators, and policy makers, and partnership with patient organisations. Such interactions are increasingly taking place, with exemplars including interactions with the All Party Parliamentary Group on Acquired Brain Injury in the UK, the production of the NASEM report in the USA, and interactions with the US Food and Drug Administration. More interactions should be encouraged, and future discussions with regulators should include debates around consent from patients with acute mental incapacity and data sharing. Data sharing is strongly advocated by funding agencies. From January 2023, the US National Institutes of Health will require upload of research data into public repositories, but the EU requires data controllers to safeguard data security and privacy regulation. The tension between open data-sharing and adherence to privacy regulation could be resolved by cross-dataset analyses on federated platforms, with the data remaining at their original safe location. Tools already exist for conventional statistical analyses on federated platforms, however federated machine learning requires further development. Support for further development of federated platforms, and neuroinformatics more generally, should be a priority.

This update to the 2017 Commission presents new insights and challenges across a range of topics around TBI: epidemiology and prevention (section 1 ); system of care (section 2 ); clinical management (section 3 ); characterisation of TBI (section 4 ); outcome assessment (section 5 ); prognosis (Section 6 ); and new directions for acquiring and implementing evidence (section 7 ). Table 1 summarises key messages from this Commission and proposes recommendations for the way forward to advance research and clinical management of TBI.

Effects of animal-assisted psychotherapy incorporating mindfulness and self-compassion in neurorehabilitation: a randomized controlled feasibility trial

Transdiagnostic psychotherapeutic approaches are increasingly used in neurorehabilitation to address psychological distress. Animal-assistance is thought to increase efficacy. The present study evaluates a psychotherapeutic mindfulness- and self-compassion-based group intervention (MSCBI) with and without animal-assistance for patients with acquired brain injury. Patients (N = 31) were randomly assigned to the 6-week intervention with (n = 14) or without animal-assistance (n = 17). Primary outcome was psychological distress at post- and follow-up treatment, secondary outcomes were changes within-session of patients’ emotional states, adherence to treatment and attrition. Psychological distress significantly decreased in both groups from pre- to follow-up treatment with no difference between groups. Patients in the animal-assisted MSCBI group reported significantly higher increases in feeling secure, accepted, comforted, grateful, motivated and at ease during the sessions compared to patients in the MSCBI group without animal-assistance. Adherence to sessions was significantly higher in the animal-assisted MSCBI group. Attrition did not significantly differ between groups. Our results show that both MSCBIs with and without animal-assistance are feasible and effective in reducing psychological distress in patients with acquired brain injury. The significant changes within-sessions mainly in relationship-based emotional states and the higher treatment adherence suggest additional effects of animal-assistance. Animal-assistance might increase acceptability and patients’ commitment to psychotherapy.

The Role of Establishing Neurosurgical Specialist Nurse Working Group in the Recovery and Prevention of Negative Psychological Emotion after Meningioma Surgery

In this research paper, we will explore the role of establishing a neurosurgical specialist nurse working group in the recovery and prevention of negative psychological emotions after meningioma surgery. For this study, 42 meningioma patients who were treated before the establishment of a neurosurgery specialist nurse working group from January 2019 to December 2019. They were selected as the control group. In contrast, 42 meningioma patients admitted after the establishment of the neurosurgery specialist nurse group from January 2020 to December 2020 were selected as the study group. The postoperative recovery (time of stay in the intensive care unit, time of first eating, wakeup time, time of defecation for the first time, and hospitalization time), short-term prognosis, and nursing satisfaction scores of the two groups were calculated, and the post-traumatic stress disorder scale (PTSD-SS), medical coping style questionnaire (MCMQ), and National Institutes of Health Stroke Scale (NIHSS) were compared. Also, the changes in the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) score contributes to the comprehensive analysis of the role of the establishment of neurosurgical specialist nurse working group in the recovery and prevention of negative psychological emotion after meningioma operation. The satisfaction scores in the study group of patients in physical care, receiving information, support, respect, and nursing process were higher than the control group probability (P < 0.05). The first feeding time, defecation time, out of bed, the stay time in the intensive care unit, and the hospitalization time of the study group were shorter than those of the control group (P < 0.05). Before nursing, there was no difference in NIHSS score, SAS score, and SDS scores between the two groups. However, after nursing, the NIHSS score, SAS score, and SDS score of the study group were fairly lower than the control group. Moreover, the Karnofsky functional status scale (KPS) scores of the two groups increased gradually. The KPS scores of the study group at 1 month, 2 months, and 3 months after operation were significantly higher than those of the control group (P < 0.05). Before nursing, there was no significant difference in the scores of post-traumatic stress disorder between the two groups (P > 0.05). After nursing, the scores of subjective evaluation, symptom avoidance, repeated experience, and social dysfunction in the study group were lower than those in the control group (P < 0.05). Before nursing, there was no significant difference in coping scores between the control group and the research group (P > 0.05), but after nursing, the avoidance and compliance scores of the research group were significantly higher than those of the control group (P < 0.05).Similarly, the scores of avoidance and yield in the study group were significantly lower than those in the control group (P < 0.05). In the study group, 1 patient had an incision infection and 1 patient had epilepsy, and the total incidence of postoperative complications was 4.76%. In the control group, 4 patients had incision infection, 1 case of an intracranial hematoma, 3 cases of deep venous thrombosis, and 3 cases of epilepsy. The total incidence of postoperative complications in the study group was 26.19%, while the incidence of postoperative complications in the study group was lower than in the control group (P < 0.05).

The Kynurenine Pathway in Traumatic Brain Injury: Implications for Psychiatric Outcomes

Traumatic brain injury (TBI) is an established risk factor for the development of psychiatric disorders, especially depression and anxiety. However, the mechanistic pathways underlying this risk remain unclear, limiting treatment options and hindering the identification of clinically useful biomarkers. One salient pathophysiological process implicated in both primary psychiatric disorders and TBI is inflammation. An important consequence of inflammation is the increased breakdown of tryptophan to kynurenine and, subsequently, the metabolism of kynurenine into several neuroactive metabolites, including the neurotoxic NMDA receptor agonist quinolinic acid and the neuroprotective NMDA receptor antagonist kynurenic acid. Here, we review studies of the kynurenine pathway (KP) in TBI and examine their potential clinical implications. The weight of the literature suggests that there is increased production of neurotoxic kynurenines such as quinolinic acid in TBI of all severities and that elevated quinolinic acid concentrations in both the cerebrospinal fluid and blood are a negative prognostic indicator, being associated with death, magnetic resonance imaging abnormalities, increased depressive and anxiety symptoms, and prolonged recovery. We hypothesize that an imbalance in KP metabolism is also one molecular pathway through which the TBI-induced neurometabolic cascade may predispose to the development of psychiatric sequelae. If this model is correct, KP metabolites could serve to predict who is likely to develop psychiatric illness while drugs that target the KP could help to prevent or treat depression and anxiety arising in the context of TBI.

Effects of Sevoflurane and Propofol on Posttraumatic Stress Disorder After Emergency Trauma: A Double-Blind Randomized Controlled Trial

OBJECTIVE

Posttraumatic stress disorder (PTSD) is a frequent and disabling consequence of traumatic events. A previous study found that early use of propofol was a potential risk factor for PTSD. This prospective study aimed to investigate the effect of propofol and sevoflurane on PTSD after emergency surgery in trauma patients.

METHODS

A total of 300 trauma patients undergoing emergency surgery were randomly divided into two groups and anesthetized with propofol and/or sevoflurane. Perioperative clinical data were collected. The incidence of PTSD was evaluated with the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) in the two groups 1 month after the operation. The relevance of the injury time and CAPS-5 scores was assessed by Spearman correlation analysis. Logistic regression analysis was used to analyze the risk factors for PTSD.

RESULTS

The incidence of PTSD in the propofol group was higher than that in the sevoflurane group 1 month postoperatively (23.2 vs. 12.2%, P = 0.014). The injury time was negatively correlated with the CAPS-5 score in the propofol group (r = -0.226, P < 0.001). In the logistic regression analysis, the utilization of propofol was an independent risk factor for PTSD (P = 0.017).

CONCLUSION

Early use of propofol general anesthesia in emergency surgery for trauma patients may increase the risk of PTSD.

CLINICAL TRIAL REGISTRATION

www.chictr.org.cn, identifier: ChiCTR2100050202.

Post-Traumatic Stress Disorder Symptoms Are Related to Cognition after Complicated Mild and Moderate Traumatic Brain Injury but Not Severe and Penetrating Traumatic Brain Injury

Although post-traumatic stress disorder (PTSD) has been associated with worse cognitive outcomes after mild traumatic brain injury (TBI), its impact has not been evaluated after more severe TBI. This study aimed to determine whether PTSD symptoms are related to cognition after complicated mild, moderate, severe, and penetrating TBI. Service members (n = 137) with a history of complicated mild/moderate TBI (n = 64) or severe/penetrating TBI (n = 73) were prospectively enrolled from United States Military Treatment Facilities. Participants completed a neuropsychological assessment one year or more post-injury. Six neuropsychological composite scores and an overall test battery mean (OTBM) were considered. Participants were excluded if there was evidence of invalid responding. Hierarchical linear regressions were conducted evaluating neuropsychological performance. The interaction between TBI severity and PTSD Checklist-Civilian version total score was significant for processing speed (β = 0.208, p = 0.034) and delayed memory (β = 0.239, p = 0.021) and trended toward significance for immediate memory (β = 0.190, p = 0.057) and the OTBM (β = 0.181, p = 0.063). For each of these composite scores, the relationship between PTSD symptoms and cognition was stronger in the complicated mild/moderate TBI group than the severe/penetrating TBI group. Within the severe/penetrating TBI group, PTSD symptoms were unrelated to cognitive performance. In contrast, within the complicated mild/moderate TBI group, PTSD symptoms were significantly related to processing speed (R²Δ = 0.077, β = -0.280, p = 0.019), immediate memory (R²Δ = 0.197, β = -0.448, p < 0.001), delayed memory (R²Δ = 0.176, β = -0.423, p < 0.001), executive functioning (R²Δ = 0.100, β = -0.317, p = 0.008), and the OTBM (R²Δ = 0.162, β = -0.405, p < 0.001). The potential impact of PTSD symptoms on cognition, over and above the impact of brain injury alone, should be considered with service members and veterans with a history of complicated mild/moderate TBI. In addition, in research comparing cognitive outcomes between patients with histories of complicated-mild, moderate, severe, and/or penetrating TBI, it will be important to account for PTSD symptoms.

The clinical characterization of the adult patient with an anxiety or related disorder aimed at personalization of management

The clinical construct of "anxiety neurosis" was broad and poorly defined, so that the delineation of specific anxiety disorders in the DSM-III was an important advance. However, anxiety and related disorders are not only frequently comorbid, but each is also quite heterogeneous; thus diagnostic manuals provide only a first step towards formulating a management plan, and the development of additional decision support tools for the treatment of anxiety conditions is needed. This paper aims to describe systematically important domains that are relevant to the personalization of management of anxiety and related disorders in adults. For each domain, we summarize the available research evidence and review the relevant assessment instruments, paying special attention to their suitability for use in routine clinical practice. We emphasize areas where the available evidence allows the clinician to personalize the management of anxiety conditions, and we point out key unmet needs. Overall, the evidence suggests that we are becoming able to move from simply recommending that anxiety and related disorders be treated with selective serotonin reuptake inhibitors, cognitive-behavioral therapy, or their combination, to a more complex approach which emphasizes that the clinician has a broadening array of management modalities available, and that the treatment of anxiety and related disorders can already be personalized in a number of important respects.

Alzheimer's disease neuropathology is exacerbated following traumatic brain injury. Neuroprotection by co-administration of nanowired mesenchymal stem cells and cerebrolysin with monoclonal antibodies to amyloid beta peptide

Military personnel are prone to traumatic brain injury (TBI) that is one of the risk factors in developing Alzheimer's disease (AD) at a later stage. TBI induces breakdown of the blood-brain barrier (BBB) to serum proteins into the brain and leads to extravasation of plasma amyloid beta peptide (ΑβP) into the brain fluid compartments causing AD brain pathology. Thus, there is a need to expand our knowledge on the role of TBI in AD. In addition, exploration of the novel roles of nanomedicine in AD and TBI for neuroprotection is the need of the hour. Since stem cells and neurotrophic factors play important roles in TBI and in AD, it is likely that nanodelivery of these agents exert superior neuroprotection in TBI induced exacerbation of AD brain pathology. In this review, these aspects are examined in details based on our own investigations in the light of current scientific literature in the field. Our observations show that TBI exacerbates AD brain pathology and TiO₂ nanowired delivery of mesenchymal stem cells together with cerebrolysin-a balanced composition of several neurotrophic factors and active peptide fragments, and monoclonal antibodies to amyloid beta protein thwarted the development of neuropathology following TBI in AD, not reported earlier.

Psychiatric and cognitive comorbidities of persistent post-traumatic headache attributed to mild traumatic brain injury

OBJECTIVE

To investigate the association of psychiatric and cognitive comorbidities with persistent post-traumatic headache (PTH) attributed to mild traumatic brain injury (TBI).

METHODS

A total of 100 patients with persistent PTH attributed to mild TBI and 100 age- and gender-matched healthy controls free of mild TBI were enrolled between July 2018 and June 2019. Quality of sleep was evaluated using the Pittsburgh Sleep Quality Index, while symptoms of anxiety and depression were assessed using the Hospital Anxiety and Depression Scale. Cognitive impairment was evaluated using the Montreal Cognitive Assessment questionnaire, while post-traumatic stress disorder (PTSD) was assessed using the Harvard Trauma Questionnaire.

RESULTS

In 100 patients with persistent PTH, 85% reported poor quality sleep, compared with 42% of healthy controls (P < 0.01). The relative frequency of probable to high risk of anxiety was 52% in the persistent PTH group vs. 8% in healthy controls (P < 0.01), while the relative frequency of probable to high risk of depression was 42% in the persistent PTH group vs. 2% in healthy controls (P < 0.01). Furthermore, 27% of the patients with persistent PTH had mild cognitive impairment while 10% had probable PTSD.

CONCLUSIONS

Poor quality of sleep as well as symptoms suggestive of anxiety and depression were more common in patients with persistent PTH than healthy controls. Clinicians should screen patients with persistent PTH for these comorbidities and develop treatment plans that account for their presence.

Teasing apart trauma: neural oscillations differentiate individual cases of mild traumatic brain injury from post-traumatic stress disorder even when symptoms overlap

Post-traumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) are highly prevalent and closely related disorders. Affected individuals often exhibit substantially overlapping symptomatology - a major challenge for differential diagnosis in both military and civilian contexts. According to our symptom assessment, the PTSD group exhibited comparable levels of concussion symptoms and severity to the mTBI group. An objective and reliable system to uncover the key neural signatures differentiating these disorders would be an important step towards translational and applied clinical use. Here we explore use of MEG (magnetoencephalography)-multivariate statistical learning analysis in identifying the neural features for differential PTSD/mTBI characterisation. Resting state MEG-derived regional neural activity and coherence (or functional connectivity) across seven canonical neural oscillation frequencies (delta to high gamma) were used. The selected features were consistent and largely confirmatory with previously established neurophysiological markers for the two disorders. For regional power from theta, alpha and high gamma bands, the amygdala, hippocampus and temporal areas were identified. In line with regional activity, additional connections within the occipital, parietal and temporal regions were selected across a number of frequency bands. This study is the first to employ MEG-derived neural features to reliably and differentially stratify the two disorders in a multi-group context. The features from alpha and beta bands exhibited the best classification performance, even in cases where distinction by concussion symptom profiles alone were extremely difficult. We demonstrate the potential of using 'invisible' neural indices of brain functioning to understand and differentiate these debilitating conditions.

Prevalence of and risk factors for post-intensive care syndrome: Multicenter study of patients living at home after treatment in 12 Japanese intensive care units, SMAP-HoPe study

Few studies have examined the epidemiology of post-intensive care syndrome in Japan. This study investigated the mental health and quality of life of patients living at home in Japan after intensive care unit (ICU) discharge. Additionally, we examined whether unplanned admission to the ICU was associated with more severe post-traumatic stress disorder (PTSD), anxiety, and depressive symptoms. An ambidirectional cohort study was conducted at 12 ICUs in Japan. Patients who stayed in the ICU for > 3 nights and were living at home for 1 year afterward were included. One year after ICU discharge, we retrospectively screened patients and performed a mail survey on a monthly basis, including the Impact of Event Scale—Revised (IER-S), the Hospital Anxiety Depression Scale (HADS), and the EuroQOL—5 Dimension (EQ-5D-L) questionnaires. Patients’ characteristics, delirium and coma status, drugs used, and ICU and hospital length of stay were assessed from medical records. Descriptive statistics and multilevel linear regression modeling were used to examine our hypothesis. Among 7,030 discharged patients, 854 patients were surveyed by mail. Of these, 778 patients responded (response rate = 91.1%). The data from 754 patients were analyzed. The median IES-R score was 3 (interquartile range [IQR] = 1‒9), and the prevalence of suspected PTSD was 6.0%. The median HADS anxiety score was 4.00 (IQR = 1.17‒6.00), and the prevalence of anxiety was 16.6%. The median HADS depression score was 5 (IQR = 2‒8), and the prevalence of depression was 28.1%. EQ-5D-L scores were lower in our participants than in the sex- and age-matched Japanese population. Unplanned admission was an independent risk factor for more severe PTSD, anxiety, and depressive symptoms. Approximately one-third of patients in the general ICU population experienced mental health issues one year after ICU discharge. Unplanned admission was an independent predictor for more severe PTSD symptoms.

Military TBI—What civilian primary care providers should know

In June 2019, the Department of Veterans Affairs (VA) launched the VA Mission Act, which expanded veterans’ health-care access to the private sector. Since civilian primary care providers may see more veterans in their practice, it will be important to understand the unique experiences, comorbidities, and culture of this population in order to provide optimal care. Military service members (SMs) are at an increased risk for traumatic brain injury (TBI), and comorbidities, such as post traumatic stress disorder (PTSD), increasing the likelihood of prolonged symptoms. Military training and repetitive low-level blast exposure may cause symptoms similar to TBI or increase long-term negative effects in SMs. Military culture often has a strong influence in this population. Those who serve in the military identify with military values and have a strong team mentality, which places emphasis on the mission above all else, not accepting defeat, and not ever leaving a fellow SM behind. These values can impact the way a SM/veteran seeks care and/or communicates with his or her health-care provider. Taking a detailed history to understand how these factors apply, as well as screening for mental health comorbidities, are recommended. Understanding the military cultural influences can assist in promoting a stronger therapeutic alliance and encourage more open communication. Ultimately, it is the trusting and respectful relationship between the SM/veteran and the provider that will determine the most effective treatment and result in the most effective resolution of TBI and comorbid symptoms.

Sensorimotor dysfunction in a mild mouse model of cortical contusion injury without significant neuronal loss is associated with increases in inflammatory proteins with innate but not adaptive immune functions

Traumatic brain injury is a leading cause of mortality and morbidity in the United States. Acute trauma to the brain triggers chronic secondary injury mechanisms that contribute to long-term neurological impairment. We have developed a single, unilateral contusion injury model of sensorimotor dysfunction in adult mice. By targeting a topographically defined neurological circuit with a mild impact, we are able to track sustained behavioral deficits in sensorimotor function in the absence of tissue cavitation or neuronal loss in the contused cortex of these mice. Stereological histopathology and multiplex enzyme-linked immunosorbent assay proteomic screening confirm contusion resulted in chronic gliosis and the robust expression of innate immune cytokines and monocyte attractant chemokines IL-1β, IL-5, IL-6, TNFα, CXCL1, CXCL2, CXCL10, CCL2, and CCL3 in the contused cortex. In contrast, the expression of neuroinflammatory proteins with adaptive immune functions was not significantly modulated by injury. Our data support widespread activation of innate but not adaptive immune responses, confirming an association between sensorimotor dysfunction with innate immune activation in the absence of tissue or neuronal loss in our mice.

Low brain endocannabinoids associated with persistent non-goal directed nighttime hyperactivity after traumatic brain injury in mice

Traumatic brain injury (TBI) is a frequent cause of chronic headache, fatigue, insomnia, hyperactivity, memory deficits, irritability and posttraumatic stress disorder. Recent evidence suggests beneficial effects of pro-cannabinoid treatments. We assessed in mice levels of endocannabinoids in association with the occurrence and persistence of comparable sequelae after controlled cortical impact in mice using a set of long-term behavioral observations in IntelliCages, motor and nociception tests in two sequential cohorts of TBI/sham mice. TBI mice maintained lower body weights, and they had persistent low levels of brain ethanolamide endocannabinoids (eCBs: AEA, OEA, PEA) in perilesional and subcortical ipsilateral brain tissue (6 months), but rapidly recovered motor functions (within days), and average nociceptive responses were within normal limits, albeit with high variability, ranging from loss of thermal sensation to hypersensitivity. TBI mice showed persistent non-goal directed nighttime hyperactivity, i.e. they visited rewarding and non-rewarding operant corners with high frequency and random success. On successful visits, they made more licks than sham mice resulting in net over-licking. The lower the eCBs the stronger was the hyperactivity. In reward-based learning and reversal learning tasks, TBI mice were not inferior to sham mice, but avoidance memory was less stable. Hence, the major late behavioral TBI phenotype was non-goal directed nighttime hyperactivity and "over-licking" in association with low ipsilateral brain eCBs. The behavioral phenotype would agree with a "post-TBI hyperactivity disorder". The association with persistently low eCBs in perilesional and subcortical regions suggests that eCB deficiency contribute to the post-TBI psychopathology.