Depression in Men and Women One Year Following Traumatic Brain Injury (TBI): A TBI Model Systems Study

Mood Tracker: A Randomized Controlled Trial of a Self-Monitoring Intervention for Emotional Distress After Traumatic Brain Injury

OBJECTIVE

Persons with traumatic brain injury (TBI) frequently experience emotional distress (ED) manifested in anxiety and depression. However, they may not access mental health services due to external (eg, access, transportation, and cost) or internal (eg, stigma and discomfort with traditional counseling) barriers. Based on substantial literature indicating that self-monitoring can ameliorate several health conditions, we conducted a randomized, parallel group, wait-list control (WLC) trial of a self-monitoring intervention to decrease ED after TBI.

SETTING

Community in the southwestern United States.

PARTICIPANTS

Persons with medically documented complicated mild, moderate, and severe TBI.

DESIGN

About 127 participants were randomized in blocks of 6 to an active treatment (AT) group, wherein they completed multiple assessments of ED each week over a 6-week period via a smartphone app, or a WLC group in a parallel group, controlled trial. Participants received weekly support calls to promote self-monitoring of ED using ecological momentary assessment.

MAIN MEASURES

ED (Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7), Satisfaction with Life Scale, and Participation Assessment with Recombined Tools-Objective.

RESULTS

Analysis of the primary study outcome at 6 weeks after initiation of treatment for the AT group did not demonstrate that self-monitoring was effective in decreasing ED as compared to the WLC group. Brief support calls made weekly to promote compliance with self-monitoring were effective in achieving the target number of self-assessments. About 80% of support calls lasted less than 5 minutes. Greater ED was associated with lower life satisfaction and lower participation indicating the importance of addressing ED in persons with TBI.

CONCLUSION

Additional work is needed to develop nontraditional interventions to circumvent barriers that prevent persons with TBI from accessing care for ED. Brief support calls may be an effective, low-cost intervention to improve compliance with self-monitoring or self-management interventions.

An overview of preclinical models of traumatic brain injury (TBI): relevance to pathophysiological mechanisms

Background

Traumatic brain injury (TBI) is a major cause of morbidity and mortality, affecting millions annually worldwide. Although the majority of TBI patients return to premorbid baseline, a subset of patient can develop persistent and often debilitating neurocognitive and behavioral changes. The etiology of TBI within the clinical setting is inherently heterogenous, ranging from sport related injuries, fall related injuries and motor vehicle accidents in the civilian setting, to blast injuries in the military setting.

Objective

Animal models of TBI, offer the distinct advantage of controlling for injury modality, duration and severity. Furthermore, preclinical models of TBI have provided the necessary temporal opportunity to study the chronic neuropathological sequelae of TBI, including neurodegenerative sequelae such as tauopathy and neuroinflammation within the finite experimental timeline. Despite the high prevalence of TBI, there are currently no disease modifying regimen for TBI, and the current clinical treatments remain largely symptom based. The preclinical models have provided the necessary biological substrate to examine the disease modifying effect of various pharmacological agents and have imperative translational value.

Methods

The current review will include a comprehensive survey of well-established preclinical models, including classic preclinical models including weight drop, blast injury, fluid percussion injury, controlled cortical impact injury, as well as more novel injury models including closed-head impact model of engineered rotational acceleration (CHIMERA) models and closed-head projectile concussive impact model (PCI). In addition to rodent preclinical models, the review will include an overview of other species including large animal models and Drosophila.

Results

There are major neuropathological perturbations post TBI captured in various preclinical models, which include neuroinflammation, calcium dysregulation, tauopathy, mitochondrial dysfunction and oxidative stress, axonopathy, as well as glymphatic system disruption.

Conclusion

The preclinical models of TBI continue to offer valuable translational insight, as well as essential neurobiological basis to examine specific disease modifying therapeutic regimen.

Neurobehavioral Symptom Profiles for the Behavioral Assessment Screening Tool in Chronic Traumatic Brain Injury

OBJECTIVE

To identify neurobehavioral symptom profiles among persons with chronic traumatic brain injury (TBI) using the Behavioral Assessment Screening Tool (BAST) and to consider participant characteristics that differ between profile groups.

SETTING

Community.

PARTICIPANTS

Participants (n = 615) were English-speaking adults (≥18) and had a self-reported history of at least one TBI of any severity.

DESIGN

Secondary analysis of cross-sectional data.

MAIN MEASURES

The BAST measures neurobehavioral symptoms in the domains of Negative Affect, Fatigue, Executive Dysfunction, Impulsivity, and Substance Misuse.

RESULTS

Using latent profile analysis (LPA), we identified 3 different neurobehavioral profiles. Overall symptom frequency and differences in the pattern of symptom frequency across domains differentiated the profile groups. Average domain scores differed significantly across the profiles (P < .001) for all domains except Fatigue (P = .076). Those in profile 3 (High-Risk group) reported the most frequent symptoms across all domains (similar Negative Affect frequency as profile 1). Substance Misuse was especially high in this group. Compared to profile 2 (High Negative Affect group), participants in profile 1 (Moderate-Risk group) endorsed significantly more frequent (and more variable) symptoms across all BAST domains, particularly Impulsivity and Substance Misuse. Participants in profile 2 endorsed the least frequent symptoms across all domains. Demographic comparison showed that groups differed based on gender, age, and injury severity (mild vs moderate-severe), with profile 3 composed of the most men and the most persons in early adulthood, and profile 2 composed of the most women and those with mild TBI.

CONCLUSIONS

We differentiated 3 neurobehavioral symptom profiles among persons with chronic TBI and determined differences in sociodemographic factors between the groups. Future research should focus on validating these profiles in another sample of individuals with chronic TBI. Characterizing persons according to multidimensional symptom profiles could allow for more tailored approaches to predict and prevent long-term negative outcomes.

Biopsychosocial factors of quality of life in individuals with moderate to severe traumatic brain injury: a scoping review

PURPOSE

Individuals with moderate to severe traumatic brain injury (TBI) experience changes in their quality-of-life (QOL) post-injury. Given the vast literature that exists about QOL after TBI, a scoping review was performed to identify the different biopsychosocial factors that affect a person's QOL after a moderate to severe TBI.

METHODS

A scoping review was conducted using the following electronic databases: MEDLINE, CINAHL, Embase, and PsycINFO. Terms relating to TBI and QOL were used.

RESULTS

There were 7576 articles obtained from the databases, resulting in 535 full-text articles. Ultimately, 52 articles were extracted, which consisted of biopsychosocial QOL factors after TBI. The biopsychosocial factors of QOL after TBI included 19 biological factors (i.e., sex, TBI severity, cognition), 16 psychological factors (i.e., depression, self-efficacy, coping styles), and 19 social factors (i.e., employment, social participation, social support). Factors such as fatigue, self-awareness, transition, and discharge from hospitals are known issues in TBI literature but were minimally reported in studies in this review, identifying them as potential gaps in research.

CONCLUSION

Identifying biopsychosocial factors relating to QOL after TBI can enable health services to develop targeted rehabilitation programs for individuals with TBI.

Fecal microbiota transplantation unveils sex-specific differences in a controlled cortical impact injury mouse model

Introduction

Contusion type of traumatic brain injury (TBI) is a major cause of locomotor disability and mortality worldwide. While post-TBI deleterious consequences are influenced by gender and gut dysbiosis, the sex-specific importance of commensal gut microbiota is underexplored after TBI. In this study, we investigated the impact of controlled cortical impact (CCI) injury on gut microbiota signature in a sex-specific manner in mice.

Methods

We depleted the gut microflora of male and female C57BL/6 mice using antibiotic treatment. Thereafter, male mice were colonized by the gut microbiota of female mice and vice versa, employing the fecal microbiota transplantation (FMT) method. CCI surgery was executed using a stereotaxic impactor (Impact One™). For the 16S rRNA gene amplicon study, fecal boli of mice were collected at 3 days post-CCI (dpi).

Results and discussion

CCI-operated male and female mice exhibited a significant alteration in the genera of Akkermansia, Alistipes, Bacteroides, Clostridium, Lactobacillus, Prevotella, and Ruminococcus. At the species level, less abundance of Lactobacillus helveticus and Lactobacillus hamsteri was observed in female mice, implicating the importance of sex-specific bacteriotherapy in CCI-induced neurological deficits. FMT from female donor mice to male mice displayed an increase in genera of Alistipes, Lactobacillus, and Ruminococcus and species of Bacteroides acidifaciens and Ruminococcus gnavus. Female FMT-recipient mice from male donors showed an upsurge in the genus Lactobacillus and species of Lactobacillus helveticus, Lactobacillus hamsteri, and Prevotella copri. These results suggest that the post-CCI neurological complications may be influenced by the differential gut microbiota perturbation in male and female mice.

In her own words: a phenomenological analysis of stories told by female service members and veterans after traumatic brain injury

PURPOSE

Given the majority of Service Members and Veterans (SMV) who have sustained a traumatic brain injury (TBI) are male, the female experience with TBI has not been captured in the general understanding of TBI. To improve understanding of the experience of female SMV after TBI utilizing a qualitative phenomenological approach on stories as told by female SMV.

MATERIALS AND METHODS

Ten female SMV participated in storytelling workshops and created video stories documenting their personal experience with TBI. Workshops were hosted by the VA Palo Alto Health Care System Polytrauma System of Care (VAPAHCS PSC). A grounded thematic analysis was conducted on the video stories.

RESULTS

Three common content themes emerged from all the stories: (1) negative psychological and emotional impacts of TBI, (2) acceptance and healing process associated with recovery, and (3) military contexts. Negative psychological and emotional impacts included intrapersonal impacts such as negative emotions, suicidal ideation, and dealing with cognitive and physical challenges, and interpersonal impacts in relationships and loss of independence. Notably, all the stories acknowledged an acceptance and healing process, characterized by several subthemes including motivational factors, TBI education, spirituality, and advocacy work. Lastly, each story mentioned military context, highlighting the unique experience within this population.

CONCLUSIONS

This phenomenological examination adds evidence-based understanding to the experience after TBI among female SMV. Each story uncovered nuanced and multifaceted issues that women experience in their TBI recovery. Our findings provide context to guide future intervention on the care, support, and TBI recovery for the female SMV population.

Alexithymia as a risk factor for poor emotional outcomes in adults with acquired brain injury

Emotional disorders are pervasive in the acquired brain injury (ABI) population, adversely affecting quality of life and rehabilitation. This study aimed to explore the unique associative effects of alexithymia as measured by the Perth Alexithymia Questionnaire (PAQ; i.e., difficulty identifying positive/negative feelings, difficulty describing positive/negative feelings, and externally orientated thinking), on emotional outcomes as measured by the Depression Anxiety Stress Scale-21 (DASS-21) and Mayo-Portland Adaptability Inventory (MPAI-4) Adjustment index, in 83 adults with ABI. The addition of alexithymia to hierarchical multiple regression models (controlling for demographic, injury-related, and functional outcome variables) yielded statistically significant changes in R2 for all emotional outcome measures (i.e., Depression, Anxiety, Stress, and Adjustment). Difficulty identifying negative feelings was found to be a significant unique predictor of Depression (β = .43 p = <.001), Anxiety (β = .40, p <.001), Stress (β = .49, p <.001), and Adjustment (β = .26, p = .001). Externally oriented thinking was found to be a significant unique predictor of Adjustment (β = -.15, p = .033). These findings strengthen the argument that alexithymia, especially difficulties identifying negative feelings, may be an important risk factor for psychological distress in ABI and should be considered during early rehabilitation.

Behavioral and Psychiatric Symptoms in Patients with Severe Traumatic Brain Injury: A Comprehensive Overview

Traumatic brain injury (TBI) is defined as an altered brain structure or function produced by an external force. Adults surviving moderate and severe TBI often experience long-lasting neuropsychological and neuropsychiatric disorders (NPS). NPS can occur as primary psychiatric complications or could be an exacerbation of pre-existing compensated conditions. It has been shown that changes in behavior following moderate to severe TBI have a prevalence rate of 25-88%, depending on the methodology used by the different studies. Most of current literature has found that cognitive behavioral and emotional deficit following TBI occurs within the first six months whereas after 1-2 years the condition becomes stable. Identifying the risk factors for poor outcome is the first step to reduce the sequelae. Patients with TBI have an adjusted relative risk of developing any NPS several-fold higher than in the general population after six months of moderate-severe TBI. All NPS features of an individual's life, including social, working, and familiar relationships, may be affected by the injury, with negative consequences on quality of life. This overview aims to investigate the most frequent psychiatric, behavioral, and emotional symptoms in patients suffering from TBI as to improve the clinical practice and tailor a more specific rehabilitation training.

Electrical stimulation methods and protocols for the treatment of traumatic brain injury: a critical review of preclinical research

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of disabilities resulting from cognitive and neurological deficits, as well as psychological disorders. Only recently, preclinical research on electrical stimulation methods as a potential treatment of TBI sequelae has gained more traction. However, the underlying mechanisms of the anticipated improvements induced by these methods are still not fully understood. It remains unclear in which stage after TBI they are best applied to optimize the therapeutic outcome, preferably with persisting effects. Studies with animal models address these questions and investigate beneficial long- and short-term changes mediated by these novel modalities.

METHODS

In this review, we present the state-of-the-art in preclinical research on electrical stimulation methods used to treat TBI sequelae. We analyze publications on the most commonly used electrical stimulation methods, namely transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS) and vagus nerve stimulation (VNS), that aim to treat disabilities caused by TBI. We discuss applied stimulation parameters, such as the amplitude, frequency, and length of stimulation, as well as stimulation time frames, specifically the onset of stimulation, how often stimulation sessions were repeated and the total length of the treatment. These parameters are then analyzed in the context of injury severity, the disability under investigation and the stimulated location, and the resulting therapeutic effects are compared. We provide a comprehensive and critical review and discuss directions for future research. RESULTS AND CONCLUSION: We find that the parameters used in studies on each of these stimulation methods vary widely, making it difficult to draw direct comparisons between stimulation protocols and therapeutic outcome. Persisting beneficial effects and adverse consequences of electrical simulation are rarely investigated, leaving many questions about their suitability for clinical applications. Nevertheless, we conclude that the stimulation methods discussed here show promising results that could be further supported by additional research in this field.

Imbalance of Essential Metals in Traumatic Brain Injury and Its Possible Link with Disorders of Consciousness

Dysfunction of the complex cerebral networks underlying wakefulness and awareness is responsible for Disorders of Consciousness (DoC). Traumatic Brain Injury (TBI) is a common cause of DoC, and it is responsible for a multi-dimensional pathological cascade that affects the proper functioning of the brainstem and brain consciousness pathways. Iron (Fe), Zinc (Zn), and Copper (Cu) have a role in the neurophysiology of both the ascending reticular activating system, a multi-neurotransmitter network located in the brainstem that is crucial for consciousness, and several brain regions. We aimed to summarize the role of these essential metals in TBI and its possible link with consciousness alterations. We found that TBI alters many neuronal molecular mechanisms involving essential metals, causing neurodegeneration, neural apoptosis, synaptic dysfunction, oxidative stress, and inflammation. This final pattern resembles that described for Alzheimer's disease (AD) and other neurological and psychiatric diseases. Furthermore, we found that amantadine, zolpidem, and transcranial direct current stimulation (tDCS)-the most used treatments for DoC recovery-seem to have an effect on essential metals-related pathways and that Zn might be a promising new therapeutic approach. This review summarizes the neurophysiology of essential metals in the brain structures of consciousness and focuses on the mechanisms underlying their imbalance following TBI, suggesting their possible role in DoC. The scenario supports further studies aimed at getting a deeper insight into metals' role in DoC, in order to evaluate metal-based drugs, such as metal complexes and metal chelating agents, as potential therapeutic options.

Return to work following mild traumatic brain injury: Psychological and cognitive factors in a litigating sample in the post acute stage of recovery

The purpose of this study was to investigate return to work (RTW) rates following a single uncomplicated mild Traumatic Brain Injury (mTBI) in the post-acute stage in the context of active litigation. More specifically, we sought to determine what psychological and/or cognitive factors predict a RTW after mTBI. Archival data were obtained from a random sample of litigating patients (n = 125; 54% female; mean age: 42.96 (SD = 12.74) who were referred to a private practice for a neuropsychological examination regarding their disability status following a single uncomplicated mTBI. A hierarchical regression analysis was used to assess the predictive value of emotional symptoms and cognition with respect to RTW status. Approximately 50% of the sample did not RTW. Attentional deficits (rs = -0.248) and depressive symptoms (rs = 0.248) were significantly associated with RTW. A hierarchical regression analysis found that depressive symptoms (p < .05) were associated with RTW outcomes. These findings suggest that individuals with increased depressive symptoms are more likely to demonstrate poor RTW outcomes in the post-acute stages of mTBI. These results are of interest to clinicians as they underscore the importance of screening and early intervention for depressive symptoms following a single uncomplicated mTBI in the post-acute stages in litigating samples.

Prevalence and Correlates of Depressive Symptoms Within 6 Months After First-Time Mild Traumatic Brain Injury

OBJECTIVE

Depressive symptoms are among the most common neuropsychiatric sequelae of mild traumatic brain injury (mTBI). Very few studies have compared correlates of depressive symptoms within the first 6 months of injury in cohorts experiencing their first TBI. The authors investigated whether the correlates of depressive symptoms (being female, older, lower education, having brain lesions, experiencing worse postconcussive symptoms, and incomplete functional recovery) that have been established in populations with moderate to severe TBI were the same for individuals with first-time mTBI within the first 6 months of recovery.

METHODS

Two hundred seventeen individuals with first-time mTBI were divided into subgroups-new-onset depressive symptoms, recurrent depressive symptoms, prior depression history only, and never depressed-and compared on clinical and demographic variables and the presence of postconcussive symptoms and functional recovery at 3 and 6 months.

RESULTS

New-onset depressive symptoms developed in 12% of the cohort, whereas 11% of the cohort had recurrent depressive symptoms. Both depressive symptoms groups were more likely to comprise women and persons of color and were at higher risk for clinically significant postconcussive symptoms and incomplete functional recovery for the first 6 months postinjury.

CONCLUSIONS

Presence of depressive symptoms after first-time mTBI was associated with persistent postconcussive symptoms and incomplete functional recovery in the first 6 months. Adding to the existing literature, these findings identified correlates of depressive symptom development and poor outcomes after mTBI, thus providing further evidence that mTBI may produce persistent symptoms and functional limitations that warrant clinical attention.

Is sentence ambiguity comprehension affected after mild traumatic brain injury? Results suggest cognitive control is more important than diagnosis

BACKGROUND

Individuals with mild traumatic brain injury (mTBI) may experience chronic cognitive-linguistic impairments that are difficult to evaluate with existing measures. Garden path sentences are linguistically complex sentences that lead readers down a path to an incorrect interpretation. Previous research indicates many individuals, with or without mTBI, may have difficulty fully resolving the ambiguity of garden path sentences, a skill which may require cognitive control. Evidence suggests cognitive control can be impacted by mTBI. Thus, impairments in cognitive control are expected to correlate with interpreting ambiguous sentences.

AIMS

To examine the relationship between cognitive control and the processing of ambiguous garden path sentences in adults with mTBI. We predict individuals with mTBI will perform more poorly on ambiguous sentence tasks compared with a control group. Further, we predict that performance on this task will correlate with measures of cognitive control and working memory.

METHODS & PROCEDURES

A total of 20 adults with mTBI history and 44 adults with no significant neurological history were recruited from the community. Participants completed a computerized, ambiguous sentence measure with carefully designed comprehension questions and an abbreviated neuropsychological battery of cognitive-linguistic tasks.

OUTCOMES & RESULTS

Participants performed similarly on sentence ambiguity resolution measures across groups with a wide range in performance. A comprehension measure aimed at identifying full ambiguity resolution correlated with cognitive control across groups.

CONCLUSIONS & IMPLICATIONS

A link between cognitive control and linguistic ambiguity is confirmed in a comprehension measure by the current findings. mTBI history did not appear to change the nature of the relationship between cognitive control and ambiguity resolution. High individual variability on sentence and cognitive control measures across groups suggest that if an impairment were present, it would affect both types of tasks. Thus, testing cognitive communication following mTBI should specifically examine complex cognitive and linguistic processing.

WHAT THIS PAPER ADDS

What is already known on the subject Cognitive control and ambiguous sentence processing are known to be linked, but the circumstances and individual variability associated with when cognitive control is recruited to support sentence processing are not fully understood. Very little is known about sentence processing following TBI history, despite cognitive control commonly being impaired following mild TBI. Thus, our study was necessary to explore the theoretical and clinical relationships between cognitive control and ambiguous sentence processing in individuals with mild TBI history. What this paper adds to existing knowledge This study adds to our understanding of how cognitive control and ambiguous sentence processing are linked in those with mild TBI history, and similar to the few previous studies, there were no group differences in cognitive or sentence measures. The positive correlation between cognitive control on Stroop and a particular ambiguous sentence comprehension question targeting inhibitory control highlights that any relationship between abilities or assessment tasks must be very specific to tasks with overlapping requirements, such as inhibition. What are the potential or actual clinical implications of this work? The relationship between cognitive and ambiguous sentence measures highlights the need to assess all areas of cognition and communication in those with mild TBI history without assuming that impairments in cognitive performance will relate to communication. The overlap between abilities is highly specific and must be explored on a case-by-case basis in those with mild TBI. Evaluation and treatment should still be individualized based on the functional communication profile of the client.

Depression and Anxiety in Patients With a History of Traumatic Brain Injury: A Case-Control Study

Background

The burden of psychiatric illness following a head injury may have implications on the disease prognosis. The present study evaluated the association of depression and anxiety with traumatic brain injury (TBI).

Methods

A case-control study was conducted in Karachi, Pakistan, from 2nd July 2021 and 30th January 2022, including individuals of age 18 and above of both genders, with or without a mild head trauma history, forming the case and control groups, respectively. Individuals with previous head trauma/congenital neurological dysfunction were excluded. A mental health assessment of the participants was carried out with two scales, the Generalized Anxiety Disorder-7 (GAD-7) scale and the Public Health Questionnaire-9 (PHQ-9) scale. Other parameters like age, gender, socioeconomic status, education status, and comorbidities were also documented.

Results

A total of 62 participants were enrolled with 31 cases and 31 controls. The majority were males aged between 18 and 39 years. About 29% of the patients with a history of mild TBI had moderate to severe depression while only 22.6% of them did not have depression or had minimal depression. We found that about 29.3% of patients with TBI had severe anxiety as compared to the only two healthy controls. The majority of the control group participants did not have anxiety.

Conclusion

Traumatic head injuries and their long-term side effects can predispose patients to a myriad of psychiatric comorbidities. In this study, we found definitive evidence that both anxiety and depression had a significantly higher incidence in cohorts that suffered from mild TBI. However, we recommend large-scale and multicenter studies in the future to explore these relationships more thoroughly and comprehensively.

Glutamate Efflux across the Blood–Brain Barrier: New Perspectives on the Relationship between Depression and the Glutamatergic System

Depression is a significant cause of disability and affects millions worldwide; however, antidepressant therapies often fail or are inadequate. Current medications for treating major depressive disorder can take weeks or months to reach efficacy, have troubling side effects, and are limited in their long-term capabilities. Recent studies have identified a new set of glutamate-based approaches, such as blood glutamate scavengers, which have the potential to provide alternatives to traditional antidepressants. In this review, we hypothesize as to the involvement of the glutamate system in the development of depression. We identify the mechanisms underlying glutamate dysregulation, offering new perspectives on the therapeutic modalities of depression with a focus on its relationship to blood–brain barrier (BBB) permeability. Ultimately, we conclude that in diseases with impaired BBB permeability, such as depression following stroke or traumatic brain injury, or in neurogenerative diseases, the glutamate system should be considered as a pathway to treatment. We propose that drugs such as blood glutamate scavengers should be further studied for treatment of these conditions.

Factors related to the quality and stability of partner relationships after traumatic brain injury: A systematic literature review

OBJECTIVE

The latest literature review on partner relationships following traumatic brain injury (TBI), conducted a decade ago, discussed solely quantitative work and noted significant knowledge gaps. The current review updates and expands on this work by providing an overview of the current state of knowledge on factors related to relationship quality and stability following TBI.

DATA SOURCES

CINAHL, Embase, MEDLINE, Psychology and Behavioral Sciences Collection, APA PsycINFO, and PubMed were searched on April 23, 2020, for literature on factors associated with 1)relationship quality and 2)relationship stability following TBI.

STUDY SELECTION

English quantitative and qualitative studies investigating factors associated with relationship quality and/or stability following TBI were included. Two reviewers independently assessed eligibility. If consensus was not reached, a third reviewer's conclusion was decisive. Forty-three studies were included.

DATA EXTRACTION

Information regarding study objectives and characteristics, participant demographics, (in)dependent variables, and main findings was extracted. Study quality was rated using the JBI Checklist for Analytical Cross Sectional Studies and/or the CASP Checklist for Qualitative Research. Both were performed by the lead reviewer and checked by the second reviewer.

DATA SYNTHESIS

Thirty-eight factors related to relationship quality and/or stability were identified, covering injury characteristics (e.g., severity), body functions (e.g., personality changes), activities (e.g., communication), participation (e.g., social dependence), environment (e.g., children), and personal factors (e.g., coping strategies).

CONCLUSIONS

Relationship quality and stability following TBI are found to be related to a multitude of factors, including newly identified factors such as personality changes and dependence. Future research may wish to quantitatively investigate factors thus far only identified in qualitative research, explore possible positive effects of TBI on relationships, study the experiences of same-sex couples, and include the perspectives of both partners with and without the injury.

Literature Review of Sex Differences in mTBI

INTRODUCTION

Traumatic brain injury (TBI) remains a significant source of morbidity worldwide and is of particular concern for the military. Scientific literature examining sex differences in TBI is highly contradictory with some reporting better outcomes in men, others reporting better outcomes in women, and others reporting mixed results or no difference. While the exact cause is currently debated, the existence of such differences has important implications for surveillance techniques, treatment options, and management of long-term consequences. As the number of women within the U.S. military ranks increases and with the opening of combat roles to women in 2013, increased awareness of probable sex differences regarding TBI responses will enable better standard of care.

MATERIALS AND METHODS

Using the PubMed database, a keyword search using gender, "sex factors", "sex dependent", "gender disparity", TBI, "traumatic brain injury", mTBI (mild TBI), and "cranial trauma" was used to identify articles of interest. Results were filtered for written in the last 5 years, English, and free full text. References of relevant articles were cross-checked for additional publications. Articles familiar to the authors were also included.

RESULTS

We review literature that includes analysis of age as an interaction in TBI, hypothesized mechanisms to explain variations in outcomes between men and women, and the need for inclusion of sex as a criterion in future studies.

CONCLUSIONS

Emerging studies underscore the complexity of interpreting sex differences in TBI. The long-held belief that women have a neuroprotective advantage compared to men based on higher levels of sex hormones is being re-evaluated. Past conclusions have relied extensively on clinical studies that include a disproportionate number of men or do not stratify results based on sex. While sex hormones may be neuroprotective, underlying mechanisms are far from clarified. Future TBI studies must include women and gonadal hormone levels should be measured to address potential variables. Given the significant number of TBIs within the military, an improved understanding of TBI pathophysiology and outcomes is important considerations for mission success and servicemember longevity.

Research on Adolescents Regarding the Indirect Effect of Depression, Anxiety, and Stress between TikTok Use Disorder and Memory Loss

This research involved the participation of 3036 Chinese students in the first and second years of senior high school. The adolescents were active users of TikTok. The mediating effect of depression, anxiety, and stress between TikTok use disorder and memory loss was investigated. A forward and backward digit span test was applied to measure memory loss. Structural equation modeling (SEM) was established, and SPSS Amos was used for analysis. The results show a partial mediation effect of depression and anxiety between TikTok use disorder and forward digit span. A partial mediation effect of depression, anxiety, and stress between TikTok use disorder and backward digit span is also shown. These results also show gender differences. Attention should be given to male students, who have more depression, anxiety, and stress than female students; they also have more memory loss.

Psychedelics for Brain Injury: A Mini-Review

Objective: Stroke and traumatic brain injury (TBI) are among the leading causes of disability. Even after engaging in rehabilitation, nearly half of patients with severe TBI requiring hospitalization are left with major disability. Despite decades of investigation, pharmacologic treatment of brain injury is still a field in its infancy. Recent clinical trials have begun into the use of psychedelic therapeutics for treatment of brain injury. This brief review aims to summarize the current state of the science's relevance to neurorehabilitation, and may act as a resource for those seeking to understand the precedence for these ongoing clinical trials.

Methods: Narrative mini-review of studies published related to psychedelic therapeutics and brain injury.

Results: Recent in vitro, in vivo, and case report studies suggest psychedelic pharmacotherapies may influence the future of brain injury treatment through modulation of neuroinflammation, hippocampal neurogenesis, neuroplasticity, and brain complexity.

Conclusions: Historical data on the safety of some of these substances could serve in effect as phase 0 and phase I studies. Further phase II trials will illuminate how these drugs may treat brain injury, particularly TBI and reperfusion injury from stroke.

A Role for the Amygdala in Impairments of Affective Behaviors Following Mild Traumatic Brain Injury

Mild traumatic brain injury (TBI) results in chronic affective disorders such as depression, anxiety, and fear that persist up to years following injury and significantly impair the quality of life for patients. Although a great deal of research has contributed to defining symptoms of mild TBI, there are no adequate drug therapies for brain-injured individuals. Preclinical studies have modeled these deficits in affective behaviors post-injury to understand the underlying mechanisms with a view to developing appropriate treatment strategies. These studies have also unveiled sex differences that contribute to the varying phenotypes associated with each behavior. Although clinical and preclinical studies have viewed these behavioral deficits as separate entities with unique neurobiological mechanisms, mechanistic similarities suggest that a novel approach is needed to advance research on drug therapy. This review will discuss the circuitry involved in the expression of deficits in affective behaviors following mild TBI in humans and animals and provide evidence that the manifestation of impairment in these behaviors stems from an amygdala-dependent emotional processing deficit. It will highlight mechanistic similarities between these different types of affective behaviors that can potentially advance mild TBI drug therapy by investigating treatments for the deficits in affective behaviors as one entity, requiring the same treatment.

Considering Biological Sex in Traumatic Brain Injury

Published epidemiological studies of traumatic brain injury (TBI) of all severities consistently report higher incidence in men. Recent increases in the participation of women in sports and active military service as well as increasing awareness of the very large number of women who sustain but do not report TBI as a result of intimate partner violence (IPV) suggest that the number of women with TBI is significantly larger than previously believed. Women are also grossly under-represented in clinical and natural history studies of TBI, most of which include relatively small numbers of women, ignore the role of sex- and age-related gonadal hormone levels, and report conflicting results. The emerging picture from recent studies powered to detect effects of biological sex as well as age (as a surrogate of hormonal status) suggest young (i.e., premenopausal) women are more likely to die from TBI relative to men of the same age group, but this is reversed in the 6th and 7th decades of life, coinciding with postmenopausal status in women. New data from concussion studies in young male and female athletes extend this finding to mild TBI, since female athletes who sustained mild TBI are significantly more likely to report more symptoms than males. Studies including information on gonadal hormone status at the time of injury are still too scarce and small to draw reliable conclusions, so there is an urgent need to include biological sex and gonadal hormone status in the design and analysis of future studies of TBI.

Depression following traumatic brain injury: a comprehensive overview

Traumatic brain injury (TBI) represents a major health concern affecting the neuropsychological health; TBI is accompanied by drastic long-term adverse complications that can influence many aspects of the life of affected individuals. A substantial number of studies have shown that mood disorders, particularly depression, are the most frequent complications encountered in individuals with TBI. Post-traumatic depression (P-TD) is present in approximately 30% of individuals with TBI, with the majority of individuals experiencing symptoms of depression during the first year following head injury. To date, the mechanisms of P-TD are far from being fully understood, and effective treatments that completely halt this condition are still lacking. The aim of this review is to outline the current state of knowledge on the prevalence and risk factors of P-TD, to discuss the accompanying brain changes at the anatomical, molecular and functional levels, and to discuss current approaches used for the treatment of P-TD.

Evidence Limitations in Determining Sexually Dimorphic Outcomes in Pediatric Post-Traumatic Hypopituitarism and the Path Forward

Neuroendocrine dysfunction can occur as a consequence of traumatic brain injury (TBI), and disruptions to the hypothalamic-pituitary axis can be especially consequential to children. The purpose of our review is to summarize current literature relevant to studying sex differences in pediatric post-traumatic hypopituitarism (PTHP). Our understanding of incidence, time course, and impact is constrained by studies which are primarily small, are disadvantaged by significant methodological challenges, and have investigated limited temporal windows. Because hormonal changes underpin the basis of growth and development, the timing of injury and PTHP testing with respect to pubertal stage gains particular importance. Reciprocal relationships among neuroendocrine function, TBI, adverse childhood events, and physiological, psychological and cognitive sequelae are underconsidered influencers of sexually dimorphic outcomes. In light of the tremendous heterogeneity in this body of literature, we conclude with the common path upon which we must collectively arrive in order to make progress in understanding PTHP.

State-Level Numbers and Rates of Traumatic Brain Injury-Related Emergency Department Visits, Hospitalizations, and Deaths by Sex, 2014

OBJECTIVE

To provide state-level traumatic brain injury (TBI)-related emergency department (ED) visit, hospitalization, and death estimates by sex for 2014.

SETTING AND PARTICIPANTS

Centers for Disease Control and Prevention's Core Violence and Injury Prevention Program and State Injury Indicators-participating states.

DESIGN

Cross-sectional.

MAIN MEASURES

Number and rate of TBI-related ED visits, hospitalizations, and deaths (indicators) by sex in over 25 states.

RESULTS

Across all states that supplied data, males had higher rates of TBI-related ED visits, hospitalizations, and deaths than females. However, for some indicators, high rates for both sexes and low rates for both sexes appeared clustered in a specific region of the United States. There was also within-state variability in TBI rates by indicator and sex. For example, within-state variability between sexes ranged from as low as 2.8% for ED visits and as high as 335% for deaths.

CONCLUSION

TBI-related ED visits, hospitalizations, and deaths varied by state and by sex, and evidence was found for within-state variability in TBI rates by indicator and sex in 2014. Differences in TBI indicators by sex may have important implications for public health professionals implementing TBI prevention and care strategies at the state level.

Traumatic Brain Injuries: Unreported and Untreated in an Army Population

Introduction

In 2008, it was reported that 19.5% of service members previously deployed experienced a mild traumatic brain injury (mTBI). Fifty-seven percent of those did not seek medical care. It was suggested that concerns with seeking care involved confidentiality and career issues. Objective: This study addressed mTBI history, medical treatment history, and stigmas associated with mTBI/concussion.

Materials and Methods

An anonymous questionnaire was developed. Data collection occurred throughout March 2018 in conjunction with Brain Injury Awareness Month activities.

Results

All 5,174 volunteers were Army; 86% male; 87% were between 18 and 34 years old; 89% had &lt;14 years in the military; 35% had a combat deployment; and 10% reported having one or more mTBIs in their military careers. Of the Soldiers who reported a concussion, 52% sought medical care. Of those not seeking care, 64% reported they did not think the injury required care, followed by 18% fearing negative impact on their career. Twenty-eight percent who experienced an mTBI versus 11% who have not reported that there is a stigma associated with an mTBI.

Conclusions

Soldiers sometimes failed to report their suspected concussions and did not seek medical care. Educational efforts may increase reporting of and medical screening for potentially concussive events. Future research to determine the ramifications of unreported and untreated mTBIs/concussions is recommended.

The sex-specific interaction of the microbiome in neurodegenerative diseases

Several neurologic diseases exhibit different prevalence and severity in males and females, highlighting the importance of understanding the influence of biologic sex and gender. Beyond host-intrinsic differences in neurologic development and homeostasis, evidence is now emerging that the microbiota is an important environmental factor that may account for differences between men and women in neurologic disease. The gut microbiota is composed of trillions of bacteria, archaea, viruses, and fungi, that can confer benefits to the host or promote disease. There is bidirectional communication between the intestinal microbiota and the brain that is mediated via immunologic, endocrine, and neural signaling pathways. While there is substantial interindividual variation within the microbiota, differences between males and females can be detected. In animal models, sex-specific microbiota differences can affect susceptibility to chronic diseases. In this review, we discuss the ways in which neurologic diseases may be regulated by the microbiota in a sex-specific manner.

Comorbidity in adults with traumatic brain injury and all-cause mortality: a systematic review

OBJECTIVES

Comorbidity in traumatic brain injury (TBI) has been recognised to alter the clinical course of patients and influence short-term and long-term outcomes. We synthesised the evidence on the effects of different comorbid conditions on early and late mortality post-TBI in order to (1) examine the relationship between comorbid condition(s) and all-cause mortality in TBI and (2) determine the influence of sociodemographic and clinical characteristics of patients with a TBI at baseline on all-cause mortality.

DESIGN

Systematic review.

DATA SOURCES

Medline, Central, Embase, PsycINFO and bibliographies of identified articles were searched from May 1997 to January 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Included studies met the following criteria: (1) focused on comorbidity as it related to our outcome of interest in adults (ie, ≥18 years of age) diagnosed with a TBI; (2) comorbidity was detected by any means excluding self-report; (3) reported the proportion of participants without comorbidity and (4) followed participants for any period of time.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted the data and assessed risk of bias using the Quality in Prognosis Studies tool. Data were synthesised through tabulation and qualitative description.

RESULTS

A total of 27 cohort studies were included. Among the wide range of individual comorbid conditions studied, only low blood pressure was a consistent predictors of post-TBI mortality. Other consistent predictors were traditional sociodemographic risk factors. Higher comorbidity scale, scores and the number of comorbid conditions were not consistently associated with post-TBI mortality.

CONCLUSIONS

Given the high number of comorbid conditions that were examined by the single studies, research is required to further substantiate the evidence and address conflicting findings. Finally, an enhanced set of comorbidity measures that are suited for the TBI population will allow for better risk stratification to guide TBI management and treatment.

PROSPERO REGISTRATION NUMBER

CRD42017070033.

Sex Differences in Traumatic Brain Injury: What We Know and What We Should Know

There is growing recognition of the problem of male bias in neuroscience research, including in the field of traumatic brain injury (TBI) where fewer women than men are recruited to clinical trials and male rodents have predominantly been used as an experimental injury model. Despite TBI being a leading cause of mortality and disability worldwide, sex differences in pathophysiology and recovery are poorly understood, limiting clinical care and successful drug development. Given growing interest in sex as a biological variable affecting injury outcomes and treatment efficacy, there is a clear need to summarize sex differences in TBI. This scoping review presents an overview of current knowledge of sex differences in TBI and a comparison of human and animal studies. We found that overall, human studies report worse outcomes in women than men, whereas animal studies report better outcomes in females than males. However, closer examination shows that multiple factors including injury severity, sample size, and experimental injury model may differentially interact with sex to affect TBI outcomes. Additionally, we explore how sex differences in mitochondrial structure and function might contribute to possible sex differences in TBI outcomes. We propose recommendations for future investigations of sex differences in TBI, which we hope will lead to improved patient management, prognosis, and translation of therapies from bench to bedside.

Cognition in patients with traumatic brain injury measured by the Montreal Cognitive Assessment-Basic

Patients with traumatic brain injury (TBI) undergo cognitive impairment. We aimed to explore the cognition level in patients of all severities with different lesion sites and the effect of demographic variables, lesion site, TBI severity, and the time since the TBI on their cognitive abilities using the Montreal Cognitive Assessment-Basic (MoCA-B). A total of 67 patients with TBI were recruited from the Department of Cerebral Surgery at No. 101 Hospital of the Chinese People's Liberation Army (PLA) at out-patient follow up. A regression model was performed to assess the effect of these variables on cognition of TBI patients. As expected, age, education, and the Glasgow Coma Scale (GCS) score were found as predictors of cognition of TBI patients. Participants, who were younger, had more years of education, and a higher GCS score had better cognition, respectively. Thus, the results provide evidence for the early detection of possible different cognition impairment of TBI patients. Specifically, these findings can help predict early prognosis for patients in the course of clinical diagnosis and treatment and, thus, allow for early intervention to improve the patients' quality of life and possible extend their life.

Microglial Phagocytosis of Neurons: Diminishing Neuronal Loss in Traumatic, Infectious, Inflammatory, and Autoimmune CNS Disorders

Errors in neuron-microglial interaction are known to lead to microglial phagocytosis of live neurons and excessive neuronal loss, potentially yielding poorer clinical outcomes. Factors that affect neuron-microglial interaction have the potential to influence the error rate. Clinical comorbidities that unfavorably impact neuron-microglial interaction may promote a higher rate of neuronal loss, to the detriment of patient outcome. This paper proposes that many common, clinically modifiable comorbidities have a common thread, in that they all influence neuron-microglial interactions. Comorbidities like traumatic brain injury, infection, stress, neuroinflammation, loss of neuronal metabolic integrity, poor growth factor status, and other factors, all have the potential to alter communication between neurons and microglia. When this occurs, microglial phagocytosis of live neurons can increase. In addition, microglia can shift into a morphological form in which they express major histocompatibility complex II (MHC-II), allowing them to function as antigen presenting cells that present neuronal debris as antigen to invading T cells. This can increase risk for the development of CNS autoimmunity, or can exacerbate existing CNS autoimmunity. The detrimental influence of these comorbidities has the potential to contribute to the mosaic of factors that determine patient outcome in some CNS pathologies that have neuropsychiatric involvement, including TBI and CNS disorders with autoimmune components, where excessive neuronal loss can yield poorer clinical outcomes. Recognition of the impact of these comorbidities may contribute to an understanding of the common clinical observation that many seemingly disparate factors contribute to the overall picture of case management and clinical outcome in these complex disorders. In a clinical setting, knowing how these comorbidities can influence neuron-microglial interaction can help focus surveillance and care on a broader group of potential therapeutic targets. Accordingly, an interest in the mechanisms underlying the influence of these factors on neuron-microglial interactions is appropriate. Neuron-microglial interaction is reviewed, and the various mechanisms by which these potential comorbidities influence neuro-microglial interaction are described.

Neurobehavioral Management of the Polytrauma Veteran

Since the inception of the Afghanistan and Iraq wars, an increasing number of veterans have sought treatment from the Department of Veterans Affairs for combat-related injuries. Many veterans experience postconcussive symptoms, traumatic stress, chronic pain, sensory deficits, and/or headaches. The goal of this article was to highlight some of the challenges treatment providers may face, while providing rehabilitation specialists with important evaluation and treatment considerations in working with this population to maximize outcomes for these veterans.