Treatment for depression after traumatic brain injury: a systematic review

Exploring Synaptic Pathways in Traumatic Brain Injury: A Cross-Phenotype Genomics Approach

Traumatic brain injury (TBI), a global leading cause of mortality and disability, lacks effective treatments to enhance recovery. Synaptic remodeling has been postulated as one mechanism that influences outcomes after TBI. We sought to investigate whether common mechanisms affecting synapse maintenance are shared between TBI and other neuropsychiatric conditions using pathway enrichment tools and genome-wide genotype data, with the goal of highlighting novel treatment targets. We leveraged an integrative approach, combining data from genome-wide association studies with pathway and gene-set enrichment analyses. Literature review-based and Reactome database-driven approaches were combined to identify synapse-related pathways of interest in TBI outcome and to assess for shared associations with conditions in which synapse-related pathobiological mechanisms have been implicated, including Alzheimer's disease, schizophrenia (SCZ), major depressive disorder, post-traumatic stress disorder, attention-deficit hyperactivity disorder, and autism spectrum disorder. Gene and pathway-level enrichment analyses were conducted using MAGMA and its extensions, e- and H-MAGMA, followed by Mendelian randomization to investigate potential causal associations. Of the 98 pathways tested, 32 were significantly enriched in the included conditions. In TBI outcome, we identified significant enrichment in five pathways: "Serotonin clearance from the synaptic cleft" (p = 0.0001), "Presynaptic nicotinic acetylcholine receptors" (p = 0.0003), "Postsynaptic nicotinic acetylcholine receptors" (p = 0.0003), "Highly sodium permeable postsynaptic acetylcholine nicotinic receptors" (p = 0.0001), and "Acetylcholine binding and downstream events" pathways (p = 0.0003). These associations highlight potential involvement of the cholinergic and serotonergic systems in post-TBI recovery. Three of those pathways were shared between TBI and SCZ, suggesting possible pathophysiologic commonalities. In this study, we utilize comparative and integrative genomic approaches across brain conditions that share synaptic mechanisms to explore the pathophysiology of TBI outcomes. Our results implicate associations between TBI outcome and synaptic pathways as well as pathobiological overlap with other neuropsychiatric diseases.

Navigating Neurologic Illness: Skills in Neuropalliative Care for Persons Hospitalized with Neurologic Disease

Persons hospitalized for neurologic illness face multidimensional care needs. They can benefit from a palliative care approach that focuses on quality of life for persons with serious illness. We describe neurology provider "skills" to help meet these palliative needs: assessing the patient as a whole; facilitating conversations with patients to connect prognosis to care preferences; navigating neurologic illness to prepare patients and care partners for the future; providing high-quality end-of-life care to promote peace in death; and addressing disparities in care delivery.

Evidence-Based Review of Randomized Controlled Trials of Interventions for Mental Health Management Post-Moderate to Severe Traumatic Brain Injury

OBJECTIVE

To present an evidence-based review of randomized controlled trials (RCTs) evaluating interventions for mental health post-moderate to severe traumatic brain injury (post-MSTBI), as part of an extensive database that has been conceptualized as a living systematic review.

METHODS

Systematic searches were conducted for RCTs published in the English language in MEDLINE, PubMed, Scopus, CINAHL, EMBASE, and PsycINFO, up to and including December 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The methodological quality of RCTs was assessed using the Physiotherapy Evidence Database scale, and the level of evidence was assigned using a modified Sackett scale.

RESULTS

Eighty-seven RCTs examining mental health interventions and outcome measures post-MSTBI were included. These studies collectively enrolled 6471 participants. A total of 41 RCTs (47.1%) were conducted in the United States and 56 studies (64.4%) were published after 2010. A total of 62 RCTs (71.3%) examined nonpharmacological interventions and 25 RCTs (28.7%) examined pharmacological interventions. Effective pharmacological treatments included desipramine and cerebrolysin; methylphenidate and rivastigmine showed conflicting evidence. Cognitive behavioral therapy (CBT) was found to be effective for hopelessness, stress, and anxiety, compared to usual care; however, it may be as effective as supportive psychotherapy for depression. CBT combined with motivational interviewing may be as effective as CBT combined with nondirective counseling for depression, stress, and anxiety. Acceptance and commitment therapy was effective for anxiety, stress, and depression. Tai Chi, dance, and walking appeared to be effective for depression and stress, while other nonpharmacological treatments such as peer mentoring showed limited effectiveness.

CONCLUSION

This evidence-based review provides a comprehensive overview of the research landscape of RCTs addressing mental health post-MSTBI. The findings from these RCTs may be valuable for health care professionals, researchers, and policymakers involved in the field of mental health and neurorehabilitation.

Chronic pain after traumatic brain injury: a collaborative care approach

Introduction

Chronic pain is common after traumatic brain injury (TBI), frequently limits daily activities, and is associated with negative outcomes such as decreased community participation. Despite the negative impact of chronic pain, few people with TBI receive effective treatment. This paper describes a collaborative care (CC) intervention, TBI Care, adapted specifically to treat chronic pain in people living with TBI, emphasizing expert clinician input, cognitive behavioral therapy (CBT) techniques, and other non-pharmacological approaches for decreasing pain interference.

Methods

79 participants engaged in the CC intervention from two academic medical rehabilitation clinics with weekly assessments of pain intensity, interference, and medication use. Participant feedback on the intervention was gathered by interview with the care manager (CM) at the last treatment session and/or booster session. Provider feedback was gathered by a confidential survey post intervention.

Results

Ninety percent of participants received at least 11 of the target 12 sessions with a care manager (CM), the majority occurring over the phone. Participants endorsed an average of 7 pain locations. All participants received pain education, skills in self-monitoring, goal setting/behavioral activation and relaxation training. Pain interference scores (impact on activity and enjoyment), tracked weekly by the CM, significantly decreased across sessions. 89% of participants received recommendations for CBT skills, 65% received referrals for additional treatments targeting pain interference, and 43% received care coordination. 75% of participants reported 6 or more medications/supplements at both the first and last session, with changes recommended primarily for headache treatment. Feedback from participants and providers was positive.

Discussion

TBI Care, a novel patient-centered CC approach, was flexibly delivered, tailored to the needs of those living with TBI and chronic pain, with a high level of participant engagement, and satisfaction among participants and providers. This approach, prioritizing pain self-management strategies and other non-pharmacological approaches, along with optimizing pharmacological treatment, led to significant reductions in self-reported pain interference and intensity during the intervention. Using a CC model in TBI is feasible and successfully improved access to evidence-based treatments for chronic pain as well as outcomes for pain interference and intensity.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT03523923.

Alexithymia Prevalence, Characterization, and Associations With Emotional Functioning and Life Satisfaction: A Traumatic Brain Injury Model System Study

OBJECTIVES

Alexithymia an emotional processing deficit that interferes with a person's ability to recognize, express, and differentiate emotional states. Study objectives were to (1) determine rates of elevated alexithymia among people with moderate-to-severe traumatic brain injury (TBI) 1-year post-injury, (2) identify demographic and injury-related variables associated with high versus low-average levels of alexithymia, and (3) examine associations among alexithymia with other aspects of emotional functioning and life satisfaction.

SETTING

Data were collected during follow-up interviews across four TBI Model System (TBIMS) centers.

PARTICIPANTS

The sample consisted of 196 participants with moderate-to-severe TBI enrolled in the TBIMS. They were predominately male (77%), White (69%), and had no history of pre-injury mental health treatment (66.3%).

DESIGN

Cross-sectional survey data were obtained at study enrollment and 1-year post-injury.

MAIN MEASURES

Toronto Alexithymia Scale-20 (TAS-20) as well as measures of anger, aggression, hostility, emotional dysregulation, post-traumatic stress, anxiety, depression, resilience and life satisfaction. Sociodemographic information, behavioral health history and injury-related variables were also included.

RESULTS

High levels of alexithymia (TAS-20 score > 1.5 standard deviation above the normative mean) were observed for 14.3%. Compared to individuals with low/average levels of alexithymia, the high alexithymia group tended to have lower levels of education. At 1-year follow-up, high TAS-20 scores were strongly associated with emotional dysregulation and post-traumatic stress; moderately associated with anger, hostility, depression, anxiety, lower resilience and lower satisfaction with life; and weakly associated with aggression.

CONCLUSION

These findings provide further evidence that alexithymia is associated with poor emotional functioning and life satisfaction after TBI. Longitudinal studies are needed to determine if alexithymia is a risk factor that precipitates and predicts worse emotional outcomes in the TBI population. This line of work is important for informing treatment targets that could prevent or reduce of psychological distress after TBI.

Collaborative Care for Chronic Pain After Traumatic Brain Injury: A Randomized Clinical Trial

Importance

Chronic pain after traumatic brain injury (TBI) is prevalent and associated with poor outcomes. By providing multidisciplinary care through expert consultation, a collaborative care (CC) treatment approach may reduce pain interference.

Objective

To compare CC with usual care (UC) in decreasing pain interference.

Design, Setting, and Participants

This randomized clinical trial was conducted from July 2018 through April 2021 at 2 hospital-based academic rehabilitation medicine clinics in Seattle, Washington. Participants included adults with mild-to-severe TBI (at least 6 months before enrollment) and chronic pain. Data analysis was performed from March 30, 2022, to August 30, 2023.

Intervention

The CC intervention (called TBI Care) included up to 12 in-person or telephone visits over 16 weeks with a care manager (CM) who provided person-centered cognitive behavioral treatment. The CM met weekly with members of the expert team to review participants and discuss recommendations to optimize treatment.

Main Outcomes and Measures

The primary outcome was pain interference on the Brief Pain Inventory at treatment conclusion (4 months after randomization). Secondary outcomes included pain interference at 8 months; pain severity; symptoms of depression, anxiety, and sleep disturbance; pain-related emergency department visits; community participation; and participant satisfaction. Linear mixed-effects regression was used for analysis.

Results

A total of 1379 individuals were screened for eligibility, and 158 were randomized (79 to CC and 79 to UC). The participants were mostly women (92 participants [58%]) with a mean (SD) age of 46.8 (13.2) years and a mean (SD) of 15.3 (3.0) years of education. TBI occurred a mean (SD) of 4.0 (5.9) years (median [IQR], 1.9 [0.8-4.5] years) before enrollment. All TBI severities were included, and of 149 participants for whom TBI severity was known, the majority (97 participants [65%]) had mild TBI. In the CC group, 71 participants (90%) completed at least 11 sessions, and, at 4 months, this group had significantly lower pain interference scores compared with the UC group (mean [SD], 3.46 [2.17] vs 5.03 [2.28]). This difference was maintained at 8 months after randomization, with mean (SD) TBI care pain interference scores of 3.61 (2.22) for CC vs 4.68 (2.51) for UC. At 4 months, there was significantly lower pain severity in the CC group vs UC group (mean [SD] score, 3.63 [1.95] vs 4.90 [1.96]), as well as symptoms of depression (mean [SD] score, 8.07 [5.34] vs 11.31 [6.37]) and anxiety (mean [SD], 6.20 [5.17] vs 9.58 [6.00]). Satisfaction with pain treatment (mean [SD] score, 2.99 [1.23] vs 2.52 [1.25]), clinical care (mean [SD] score, 3.28 [1.00] vs 2.84 [1.26]), and overall health care (mean [SD] score, 3.25 [0.88] vs 2.82 [1.00]) were significantly higher in the CC group vs the UC group; global impression of change was significantly lower in the CC group vs the UC group (mean [SD] score, 2.74 [1.02] vs 3.47 [1.26]) (lower scores denote a better impression of change).

Conclusions and Relevance

In this randomized clinical trial of CC compared with UC for patients with TBI, CC was effective at reducing pain interference and was sustained at 8-month follow-up. Further research is needed to examine the implementation and cost-effectiveness of CC for TBI in other health care settings.

Trial Registration

ClinicalTrials.gov Identifier: NCT03523923.

A neuropsychological rehabilitation service delivery model for South African adults with acquired brain injury (RSDM-SA)

In low- and- middle- income countries (LMICs) such as South Africa, a high number of Acquired Brain Injuries (ABIs) and a lack of accessibility to healthcare lead to many survivors of brain injury not receiving the level of healthcare and rehabilitation required. Further, in LMICs life-saving or acute care is prioritized with an inadequate focus on the lifelong effects of ABI. This study used Program Theory to develop a Rehabilitation Service Delivery Model for South African Adults with Acquired Brain Injury (RSDM-SA) that caters for the unique nuances of a resource-constrained and culturally diverse context. The RSDM-SA has four interdependent levels, namely (i) Integration of Relevant Aspects of Explanatory Frameworks (ii) South African Contextual Influences on the Model (iii) Systemic Role players Necessary for the Model and (iv) Evidence-Based Guidelines in a Holistic Rehabilitation Process. The Model is a valuable resource in guiding future research endeavors and its contribution lies in the Model's focus on quality, accessibility, relevance, and efficiency, all of which are needed in healthcare internationally.

A Perspective on Hormonal Contraception Usage in Central Nervous System Injury

Naturally occurring life stages in women are associated with changes in the milieu of endogenous ovarian hormones. Women of childbearing age may be exposed to exogenous ovarian hormone(s) because of their use of varying combinations of estrogen and progesterone hormones-containing oral contraceptives (OC; also known as "the pill"). If women have central nervous system (CNS) injury such as spinal cord injury (SCI) and traumatic brain injury (TBI) during their childbearing age, they are likely to retain their reproductive capabilities and may use OC. Many deleterious side effects of long-term OC use have been reported, such as aberrant blood clotting and endothelial dysfunction that consequently increase the risk of myocardial infarction, venous thromboembolism, and ischemic brain injury. Although controversial, studies have suggested that OC use is associated with neuropsychiatric ramifications, including uncontrollable mood swings and poorer cognitive performance. Our understanding about how the combination of endogenous hormones and OC-conferred exogenous hormones affect outcomes after CNS injuries remains limited. Therefore, understanding the impact of OC use on CNS injury outcomes needs further investigation to reveal underlying mechanisms, promote reporting in clinical or epidemiological studies, and raise awareness of possible compounded consequences. The goal of the current review is to discuss the impacts of CNS injury on endogenous ovarian hormones and vice-versa, as well as the putative consequences of exogenous ovarian hormones (OC) on the CNS to identify potential gaps in our knowledge to consider for future laboratory, epidemiological, and clinical studies.

Cognitive behavioral therapy for managing depressive and anxiety symptoms after brain injury: a meta-analysis

BACKGROUND

Individuals with traumatic brain injury (TBI) are at increased risk of depression and anxiety, leading to impaired recovery. While cognitive-behavioral therapy (CBT) addresses anxiety and depression maintenance factors, its efficacy among those with TBI has not been clearly demonstrated. This review aims to bridge this gap in the literature.

METHODS

Several databases, including Medline, PsycInfo and EMBASE, were used to identify studies published between 1990 and 2021. Studies were included if: (1) trials were randomized controlled trials (RCT) involving CBT-based intervention targeting anxiety and/or depression; (2) participants experienced brain injury at least 3-months previous; (3) participants were ≥18 years old. An SMD ± SE, 95% CI and heterogeneity were calculated for each outcome.

RESULTS

Thirteen RCTs were included in this meta-analysis. The pooled-sample analyses suggest that CBT interventions had small immediate post-treatment effects on reducing depression (SMD ± SE: 0.391 ± 0.126, p < 0.005) and anxiety (SMD ± SE: 0.247 ± 0.081, p < 0.005). Effects were sustained at a 3-months follow-up for depression. A larger effect for CBT was seen when compared with supportive therapy than control. Another sub-analysis found that individualized CBT resulted in a slightly higher effect compared to group-based CBT.

CONCLUSION

This meta-analysis provides substantial evidence for CBT in managing anxiety and depression post-TBI.

Strain in the Midbrain: Impact of Traumatic Brain Injury on the Central Serotonin System

Traumatic brain injury (TBI) is a pervasive public health crisis that severely impacts the quality of life of affected individuals. Like peripheral forms of trauma, TBI results from extraordinarily heterogeneous environmental forces being imparted on the cranial space, resulting in heterogeneous disease pathologies. This has made therapies for TBI notoriously difficult to develop, and currently, there are no FDA-approved pharmacotherapies specifically for the acute or chronic treatment of TBI. TBI is associated with changes in cognition and can precipitate the onset of debilitating psychiatric disorders like major depressive disorder (MDD), generalized anxiety disorder (GAD), and post-traumatic stress disorder (PTSD). Complicating these effects of TBI, FDA-approved pharmacotherapies utilized to treat these disorders often fail to reach the desired level of efficacy in the context of neurotrauma. Although a complicated association, decades of work have linked central serotonin (5-HT) neurotransmission as being involved in the etiology of a myriad of neuropsychiatric disorders, including MDD and GAD. 5-HT is a biogenic monoamine neurotransmitter that is highly conserved across scales of biology. Though the majority of 5-HT is isolated to peripheral sites such as the gastrointestinal (GI) tract, 5-HT neurotransmission within the CNS exerts exquisite control over diverse biological functions, including sleep, appetite and respiration, while simultaneously establishing normal mood, perception, and attention. Although several key studies have begun to elucidate how various forms of neurotrauma impact central 5-HT neurotransmission, a full determination of precisely how TBI disrupts the highly regulated dynamics of 5-HT neuron function and/or 5-HT neurotransmission has yet to be conceptually or experimentally resolved. The purpose of the current review is, therefore, to integrate the disparate bodies of 5-HT and TBI research and synthesize insight into how new combinatorial research regarding 5-HT neurotransmission and TBI may offer an informed perspective into the nature of TBI-induced neuropsychiatric complications.

Traumatic Brain Injury-Induced Fear Generalization in Mice Involves Hippocampal Memory Trace Dysfunction and Is Alleviated by (R,S)-Ketamine

BACKGROUND

Traumatic brain injury (TBI) is a debilitating neurological disorder caused by an impact to the head by an outside force. TBI results in persistent cognitive impairments, including fear generalization and the inability to distinguish between aversive and neutral stimuli. The mechanisms underlying fear generalization have not been fully elucidated, and there are no targeted therapeutics to alleviate this symptom of TBI.

METHODS

To identify the neural ensembles mediating fear generalization, we utilized ArcCreERT2 × enhanced yellow fluorescent protein (EYFP) mice, which allow for activity-dependent labeling and quantification of memory traces. Mice were administered a sham surgery or the controlled cortical impact model of TBI. Mice were then administered a contextual fear discrimination paradigm and memory traces were quantified in numerous brain regions. In a separate group of mice, we tested if (R,S)-ketamine could decrease fear generalization and alter the corresponding memory traces in TBI mice.

RESULTS

TBI mice exhibited increased fear generalization when compared with sham mice. This behavioral phenotype was paralleled by altered memory traces in the dentate gyrus, CA3, and amygdala, but not by alterations in inflammation or sleep. In TBI mice, (R,S)-ketamine facilitated fear discrimination, and this behavioral improvement was reflected in dentate gyrus memory trace activity.

CONCLUSIONS

These data show that TBI induces fear generalization by altering fear memory traces and that this deficit can be improved with a single injection of (R,S)-ketamine. This work enhances our understanding of the neural basis of TBI-induced fear generalization and reveals potential therapeutic avenues for alleviating this symptom.

Mechanisms and treatments of chronic pain after traumatic brain injury

While pain after trauma generally resolves, some trauma patients experience pain for months to years after injury. An example, relevant to both combat and civilian settings, is chronic pain after traumatic brain injury (TBI). Headache as well as pain in the back and extremities are common locations for TBI-related chronic pain to be experienced. TBI-related pain can exist alone or can exacerbate pain from other injuries long after healing has occurred. Consequences of chronic pain in these settings include increased suffering, higher levels of disability, serious emotional problems, and worsened cognitive deficits. The current review will examine recent evidence regarding dysfunction of endogenous pain modulatory mechanisms, neuroplastic changes in the trigeminal circuitry and alterations in spinal nociceptive processing as contributors to TBI-related chronic pain. Key pain modulatory centers including the locus coeruleus, periaqueductal grey matter, and rostroventromedial medulla are vulnerable to TBI. Both the rationales and existing evidence for the use of monoamine reuptake inhibitors, CGRP antagonists, CXCR2 chemokine receptor antagonists, and interventional therapies will be presented. While consensus guidelines for the management of chronic post-traumatic TBI-related pain are lacking, several approaches to this clinically challenging situation deserve focused evaluation and may prove to be viable therapeutic options.

Delivery of Neuropsychological Interventions for Adult and Older Adult Clinical Populations: An Australian Expert Working Group Clinical Guidance Paper

Delivery of neuropsychological interventions addressing the cognitive, psychological, and behavioural consequences of brain conditions is increasingly recognised as an important, if not essential, skill set for clinical neuropsychologists. It has the potential to add substantial value and impact to our role across clinical settings. However, there are numerous approaches to neuropsychological intervention, requiring different sets of skills, and with varying levels of supporting evidence across different diagnostic groups. This clinical guidance paper provides an overview of considerations and recommendations to help guide selection, delivery, and implementation of neuropsychological interventions for adults and older adults. We aimed to provide a useful source of information and guidance for clinicians, health service managers, policy-makers, educators, and researchers regarding the value and impact of such interventions. Considerations and recommendations were developed by an expert working group of neuropsychologists in Australia, based on relevant evidence and consensus opinion in consultation with members of a national clinical neuropsychology body. While the considerations and recommendations sit within the Australian context, many have international relevance. We include (i) principles important for neuropsychological intervention delivery (e.g. being based on biopsychosocial case formulation and person-centred goals); (ii) a description of clinical competencies important for effective intervention delivery; (iii) a summary of relevant evidence in three key cohorts: acquired brain injury, psychiatric disorders, and older adults, focusing on interventions with sound evidence for improving activity and participation outcomes; (iv) an overview of considerations for sustainable implementation of neuropsychological interventions as 'core business'; and finally, (v) a call to action.

Oxyberberine an oxoderivative of berberine confers neuroprotective effects in controlled-cortical impact mouse model of traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is known as a silent epidemic that causes many deaths and disabilities worldwide. We examined the response of oxyberberine (OBB) in lipopolysaccharide-stimulated BV2 microglial cells and a controlled-cortical impact (CCI) mouse model of TBI.

METHODS

We synthesized OBB from berberine, and also prepared OBB-nanocrystals (OBB-NC). Male C57BL/6 mice were used for CCI surgery, and post-CCI neurobehavioral deficits were assessed from 1 h after injury through 21 days post-injury (dpi).

RESULTS

OBB treatment reduced the lipopolysaccharide-triggered elevated levels of reactive oxygen species, nitric oxide, and nuclear factor kappa B (NF-κB) in BV2 microglial cells, indicating a neuroprotective potential. CCI-operated mice exhibited significant neurological deficits on 1, 3, and 5 dpi in neurological severity scoring and rotarod assay. OBB (25 and 50 mg/kg/day) and OBB-NC (3 mg/kg/day) ameliorated these neurological aberrations. Mice subjected to CCI surgery also displayed anxiogenic- and depression-like behaviours, and cognitive impairments in forced-swimming test and elevated-zero maze, and novel object recognition task, respectively. Administration of OBB reduced these long-term neuropsychiatric complications, and also levels of toll-like receptor 4 (TLR4), high-motility group protein 1 (HMGB1), NF-κB, tumour necrosis factor-alpha and interleukin 6 cytokines in the ipsilateral cortex of mice.

CONCLUSION

We suggest that the administration of OBB offers neuroprotective effects via inhibition of HMGB1-mediated TLR4/NFκB pathway.

A mouse model of repeated traumatic brain injury-induced hearing impairment: Early cochlear neurodegeneration in the absence of hair cell loss

PURPOSE

Traumatic Brain Injury (TBI) is a major cause of death and disability worldwide. Mounting evidence suggests that even mild TBI injuries, which comprise >75% of all TBIs, can cause chronic post-concussive neurological symptoms, especially when experienced repetitively (rTBI). The most common post-concussive symptoms include auditory dysfunction in the form of hearing loss, tinnitus, or impaired auditory processing, which can occur even in the absence of direct damage to the auditory system at the time of injury. The mechanism by which indirect damage causes loss of auditory function is poorly understood, and treatment is currently limited to symptom management rather than preventative care. We reasoned that secondary injury mechanisms, such as inflammation, may lead to damage of the inner ear and parts of the brain used for hearing after rTBI. Herein, we established a model of indirect damage to the auditory system induced by rTBI and characterized the pathology of hearing loss.

METHODS

We established a mouse model of rTBI in order to determine a timeline of auditory pathology following multiple mild injuries. Mice were subject to controlled cortical impact at the skull midline once every 48 h, for a total of 5 hits. Auditory function was assessed via the auditory brainstem response (ABR) at various timepoints post injury. Brain and cochleae were collected to establish a timeline of cellular pathology.

RESULTS

We observed increased ABR thresholds and decreased (ABR) P1 amplitudes in rTBI vs sham animals at 14 days post-impact (dpi). This effect persisted for up to 60 days (dpi). Auditory temporal processing was impaired beginning at 30 dpi. Spiral ganglion degeneration was evident at 14 dpi. No loss of hair cells was detected at this time, suggesting that neuronal loss is one of the earliest notable events in hearing loss caused by this type of rTBI.

CONCLUSIONS

We conclude that rTBI results in chronic auditory dysfunction via damage to the spiral ganglion which occurs in the absence of any reduction in hair cell number. This suggests early neuronal damage that may be caused by systemic mechanisms similar to those leading to the spread of neuronal death in the brain following TBI. This TBI-hearing loss model provides an important first step towards identifying therapeutic targets to attenuate damage to the auditory system following head injury.

Psychiatric sequelae of traumatic brain injury - future directions in research

Despite growing appreciation that traumatic brain injury (TBI) is an important public health burden, our understanding of the psychiatric and behavioural consequences of TBI remains limited. These changes are particularly detrimental to a person's sense of self, their relationships and their participation in the wider community, and they continue to have devastating individual and cumulative effects long after TBI. This Review relates specifically to TBIs that confer objective clinical or biomarker evidence of structural brain injury; symptomatic head injuries without such evidence are outside the scope of this article. Common psychiatric, affective and behavioural sequelae of TBI and their proposed underlying mechanisms are outlined, along with a brief overview of current treatments. Suggestions for how scientists and clinicians can work together in the future to address the chasms in clinical care and knowledge are discussed in depth.

Precision functional MRI mapping reveals distinct connectivity patterns for depression associated with traumatic brain injury

Depression associated with traumatic brain injury (TBI) is believed to be clinically distinct from primary major depressive disorder (MDD) and may be less responsive to conventional treatments. Brain connectivity differences between the dorsal attention network (DAN), default mode network (DMN), and subgenual cingulate have been implicated in TBI and MDD. To characterize these distinctions, we applied precision functional mapping of brain network connectivity to resting-state functional magnetic resonance imaging data from five published patient cohorts, four discovery cohorts (n = 93), and one replication cohort (n = 180). We identified a distinct brain connectivity profile in TBI-associated depression that was independent of TBI, MDD, posttraumatic stress disorder (PTSD), depression severity, and cohort. TBI-associated depression was independently associated with decreased DAN-subgenual cingulate connectivity, increased DAN-DMN connectivity, and the combined effect of both. This effect was stronger when using precision functional mapping relative to group-level network maps. Our results support the possibility of a physiologically distinct "TBI affective syndrome," which may benefit from individualized neuromodulation approaches to target its distinct neural circuitry.

Host-Microbiome Interactions: Tryptophan Metabolism and Aromatic Hydrocarbon Receptors after Traumatic Brain Injury

Traumatic brain injury refers to the damage caused to intracranial tissues by an external force acting on the head, leading to both immediate and prolonged harmful effects. Neuroinflammatory responses play a critical role in exacerbating the primary injury during the acute and chronic phases of TBI. Research has demonstrated that numerous neuroinflammatory responses are mediated through the "microbiota-gut-brain axis," which signifies the functional connection between the gut microbiota and the brain. The aryl hydrocarbon receptor (AhR) plays a vital role in facilitating communication between the host and microbiota through recognizing specific ligands produced directly or indirectly by the microbiota. Tryptophan (trp), an indispensable amino acid in animals and humans, represents one of the key endogenous ligands for AhR. The metabolites of trp have significant effects on the functioning of the central nervous system (CNS) through activating AHR signalling, thereby establishing bidirectional communication between the gut microbiota and the brain. These interactions are mediated through immune, metabolic, and neural signalling mechanisms. In this review, we emphasize the co-metabolism of tryptophan in the gut microbiota and the signalling pathway mediated by AHR following TBI. Furthermore, we discuss the impact of these mechanisms on the underlying processes involved in traumatic brain injury, while also addressing potential future targets for intervention.

Multidimensional Frailty and Traumatic Brain Injury among Older Adults: A Literature Review

Background

Numerous health conditions in the older adult population can be attributed to falls, including traumatic brain injury (TBI), which can lead to devastating short and long-term sequelae. Older adults are also more likely to experience frailty, which encompasses physical, psychological, and social deficits that may lead to adverse health outcomes. Our literature review synthesizes current evidence for understanding frailty in the context of TBI among older adults using the Integral Model of Frailty as a framework.

Content Synthesis

A total of 32 articles were identified, and 9 articles were included. The results of this review indicate that outcomes resulting from TBI are closely linked to the physical, psychological, and social domains of frailty.

Conclusions

A small amount of literature currently examines frailty in the context of TBI among older adults. Using the Integral Model of Frailty to understand frailty in the context of TBI can help clinicians anticipate patient outcomes and improve care plans. We emphasize the need for a greater understanding of TBI concerning frailty to improve health outcomes among older adult patients.

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.

Photobiomodulation for Major Depressive Disorder: Linking Transcranial Infrared Light, Biophotons and Oxidative Stress

ABSTRACT

Incompletely treated major depressive disorder (MDD) poses an enormous global health burden. Conventional treatment for MDD consists of pharmacotherapy and psychotherapy, though a significant number of patients do not achieve remission with such treatments. Transcranial photobiomodulation (t-PBM) is a promising novel therapy that uses extracranial light, especially in the near-infrared (NIR) and red spectra, for biological and therapeutic effects. The aims of this Review are to evaluate the current clinical and preclinical literature on t-PBM in MDD and to discuss candidate mechanisms for effects of t-PBM in MDD, with specific attention to biophotons and oxidative stress. A search on PubMed and ClinicalTrials.gov identified clinical and preclinical studies using t-PBM for the treatment of MDD as a primary focus. After a systematic screening, only 19 studies containing original data were included in this review (9 clinical and 10 preclinical trials). Study results demonstrate consensus that t-PBM is a safe and potentially effective treatment; however, varying treatment parameters among studies complicate definitive conclusions about efficacy. Among other mechanisms of action, t-PBM stimulates the complex IV of the mitochondrial respiratory chain and induces an increase in cellular energy metabolism. We suggest that future trials include biological measures to better understand the mechanisms of action of t-PBM and to optimize treatment efficiency. Of particular interest going forward will be studying potential effects of t-PBM-an external light source on the NIR spectra-on neural circuitry implicated in depression.

Incidence and Prediction of Chronic Depression Following Aneurysmal Subarachnoid Hemorrhage: A Single-Center 17-Year Experience

OBJECTIVE

The incidence and risk factors for chronic depression after aneurysmal subarachnoid hemorrhage (aSAH) are described.

METHODS

Patients with aSAH treated at a single institution (January 1, 2003-December 31, 2019) and a modified Rankin Scale score ≤3 at follow-up who were evaluated for chronic depression were analyzed. Chronic depression was defined using a depression screening questionnaire as ≥5 positive answers for symptoms lasting >2 weeks. A predictive model was designed for the primary outcome of depression.

RESULTS

Among 1419 patients with aSAH, 460 patients were analyzed; 130 (28%) had major depressive disorder. Mean follow-up was >6 years. Higher depression rates were associated with tobacco smoking (odds ratio [OR] = 2.64, P < 0.001), illicit drug use (OR = 2.35, P = 0.007), alcohol use disorder (1.92, P = 0.04), chronic obstructive pulmonary disease (COPD) (OR=2.68, P = 0.03), and vasospasm requiring angioplasty (OR=2.09, P = 0.048). The predictive model included tobacco smoking, illicit drug use, liver disease, COPD, diabetes, nonsaccular aneurysm type, anterior communicating artery or anterior cerebral artery aneurysm location, refractory spasm requiring angioplasty, and a modified Rankin Scale score at discharge of >1 (P ≤ 0.03). The model performed with appropriate goodness of fit and an area under the receiver operator curve of 0.70 for depression. Individual independent predictors of depression were tobacco smoking, COPD, diabetes, and nonsaccular aneurysm.

CONCLUSIONS

A substantial percentage of patients had symptoms of depression on follow-up. The proposed predictive model for depression may be a useful clinical tool to identify patients at high risk for developing depression who warrant early screening and evaluation.

Traumatic brain injury-induced fear generalization in mice involves hippocampal memory trace dysfunction and is alleviated by ( R,S )-ketamine

INTRODUCTION

Traumatic brain injury (TBI) is a debilitating neurological disorder caused by an impact to the head by an outside force. TBI results in persistent cognitive impairments, including fear generalization, the inability to distinguish between aversive and neutral stimuli. The mechanisms underlying fear generalization have not been fully elucidated, and there are no targeted therapeutics to alleviate this symptom of TBI.

METHODS

To identify the neural ensembles mediating fear generalization, we utilized the ArcCreER T2 x enhanced yellow fluorescent protein (EYFP) mice, which allow for activity-dependent labeling and quantification of memory traces. Mice were administered a sham surgery or the controlled cortical impact (CCI) model of TBI. Mice were then administered a contextual fear discrimination (CFD) paradigm and memory traces were quantified in numerous brain regions. In a separate group of mice, we tested if ( R,S )-ketamine could decrease fear generalization and alter the corresponding memory traces in TBI mice.

RESULTS

TBI mice exhibited increased fear generalization when compared with sham mice. This behavioral phenotype was paralleled by altered memory traces in the DG, CA3, and amygdala, but not by alterations in inflammation or sleep. In TBI mice, ( R,S )-ketamine facilitated fear discrimination and this behavioral improvement was reflected in DG memory trace activity.

CONCLUSIONS

These data show that TBI induces fear generalization by altering fear memory traces, and that this deficit can be improved with a single injection of ( R,S )-ketamine. This work enhances our understanding of the neural basis of TBI-induced fear generalization and reveals potential therapeutic avenues for alleviating this symptom.

Association of Traumatic Brain Injury Severity and Self-Reported Neuropsychiatric Symptoms in Wounded Military Service Members

The impact of traumatic brain injury (TBI) severity and loss of consciousness (LOC) on the development of neuropsychiatric symptoms was studied in injured service members (SMs; n = 1278) evacuated from combat settings between 2003 and 2012. TBI diagnoses of mild TBI (mTBI) or moderate-to-severe TBI (MS-TBI) along with LOC status were identified using International Classification of Diseases, Ninth Revision (ICD-9) codes and the Defense and Veterans Brain Injury Center Standard Surveillance Case Definition for TBI. Self-reported psychiatric symptoms were evaluated for post-traumatic stress disorder (PTSD) with the PTSD Checklist, Civilian Version for PTSD, the Patient Health Questionnaire-9 for major depressive disorder (MDD), and the Patient Health Questionnaire-15 for somatic symptom disorder (SSD) in two time periods post-injury: Assessment Period 1 (AP1, 0.0-2.5 months) and Assessment Period 2 (AP2, 3-12 months). mTBI, but not MS-TBI, was associated with increased neuropsychiatric symptoms: PTSD in AP1 and AP2; MDD in AP1; and SSD in AP2. A subgroup analysis of mTBI with and without LOC revealed that mTBI with LOC, but not mTBI without LOC, was associated with increased symptoms as compared to non-TBI: PTSD in AP1 and AP2; MDD in AP1; and SSD in AP1 and AP2. Moreover, mTBI with LOC was associated with increased MDD symptoms in AP2, and SSD symptoms in AP1 and AP2, compared to mTBI without LOC. These findings reinforce the need for the accurate characterization of TBI severity and a multi-disciplinary approach to address the devastating impacts of TBI in injured SMs.

A Study of 309 Patients and at One Year Follow-Up for Depression after Traumatic Brain Injury

Traumatic brain injury (TBI) is one the major causes of death and morbidity in developing countries, where depression is a common psychiatric condition among individuals with TBI. The objectives were to investigate the occurrence and severity of depression one-year post-TBI; the association between radiological findings and depression; and the risk factors. We report a cross-sectional study among adult patients who were hospitalized because of TBI in the past one year. A structured data collection form was used to collect patients' demographic data during TBI, while the Patient Health Questionnaire (PHQ)-9 questionnaire was administered to assess the level of depression at one-year post-TBI. Of the 309 patients in this study; 46.6%, 26.2%, and 27.2% had mild, moderate, and severe TBI, respectively. The overall rate of depression was 33.7%, where 22.3%, 8.7%, and 2.6% had mild, moderate, and moderately severe depression, respectively. There was a significant, positive correlation between severity of TBI and level of depression; r_s (0.427), p < 0.0001. The risk factors for depression at one-year post-TBI are moderate-severe TBI (odds ratio [OR]: 3.75, 95% confidence interval [CI] 2.03-6.90, p < 0.00), being unmarried (OR: 2.67, 95% CI 1.51-4.72, p = 0.001), female gender (OR: 2.62, 95% CI 1.25-5.46, p = 0.011), alcohol consumption (OR: 2.38, 95% CI 1.12-5.06, p = 0.024) and frontal lobe injury (OR: 1.96, 95% CI 1.05-3.68, p = 0.035). Increasing severity of TBI is associated with worsening levels of depression. Patients with frontal lobe injury have the highest risk of depression, while diffuse injury is associated with occurrence of moderate and moderately severe depression.

Higher Soluble CD163 in Blood Is Associated With Significant Depression Symptoms in Men With HIV

BACKGROUND

People with HIV (PWH) are more likely to experience depression, a highly morbid disease. More evidence is needed to better understand mechanisms of depression in PWH. We evaluated a panel of blood biomarkers in relation to depression symptoms in the Multicenter AIDS Cohort Study (MACS).

SETTING

Four sites in the United States.

METHODS

A cross-sectional analysis was performed within the MACS, a prospective study of cisgender men with and without HIV. Depression was assessed with the Center for Epidemiological Studies-Depression Scale, and six blood biomarkers were measured: GlycA, high sensitivity C-reactive protein (CRP), interleukin-6, CCL2, soluble CD14 (sCD14), and soluble CD163 (sCD163). Using univariable and multivariable logistic regression, the biomarkers and other factors were evaluated in relation to significant depression symptoms (SDS) by Center for Epidemiological Studies-Depression score ≥16.

RESULTS

784 men were analyzed; most of whom (63%) were PWH. PWH were more likely to have SDS (32% vs. 21%). In univariable analysis, higher GlycA, CRP, and sCD163 concentrations were associated with SDS. In multivariable analysis, however, only higher sCD163 concentration was associated with SDS (odds ratio = 2.30, 95% CI = 1.11 to 4.76). This relationship was driven by the PWH group (odds ratio = 2.72, 95% CI = 1.12 to 6.58) and remained significant when controlling for antidepressant use. Lack of college education was also associated with SDS.

CONCLUSIONS

Higher sCD163, a marker of macrophage activation, was significantly associated with significant depression symptoms in the MACS. Further research on this biomarker and macrophage activation in general is warranted to better understand and treat depression in PWH.

Current and Potential Pharmacologic Therapies for Traumatic Brain Injury

The present article reviewed the pharmacologic therapies of traumatic brain injury (TBI), including current and potential treatments. Pharmacologic therapies are an essential part of TBI care, and several agents have well-established effects in TBI care. In the acute phase, tranexamic acid, antiepileptics, hyperosmolar agents, and anesthetics are the mainstay of pharmacotherapy, which have proven efficacies. In the post-acute phase, SSRIs, SNRIs, antipsychotics, zolpidem and amantadine, as well as other drugs, have been used to manage neuropsychological problems, while muscle relaxants and botulinum toxin have been used to manage spasticity. In addition, increasing numbers of pre-clinical and clinical studies of pharmaceutical agents, including potential neuroprotective nutrients and natural therapies, are being carried out. In the present article, we classify the treatments into established and potential agents based on the level of clinical evidence and standard of practice. It is expected that many of the potential medicines under investigation will eventually be accepted as standard practice in the care of TBI patients.

Fluoxetine reduces organ injury and improves motor function after traumatic brain injury in mice

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in trauma patients worldwide. Brain injury is associated with significant inflammation, both within the brain and in the peripheral organs. This inflammatory response in TBI leads to a secondary injury, worsening the effects of the original brain injury. Serotonin is also linked to inflammation in the intestine and inflammatory bowel disease, but its role in the gut-brain axis is not known. We hypothesized that using fluoxetine to block serotonin reuptake would reduce organ inflammation and improve outcomes after TBI.

METHODS

C57/B6 mice were given a severe TBI using a controlled cortical impact. To measure intestinal permeability, a piece of terminal ileum was resected, the lumen was filled with 4-kDa fluorescein isothiocyanate (FITC)-dextran, and the ends were tied. The intestinal segment was submerged in buffer and fluorescence in the buffer measured over time. To measure lung permeability, 70-kDa FITC-dextran is injected retro-orbitally. Thirty minutes later, the left lung was homogenized and the fluorescence was measured. To measure performance on the rota-rod, mice were placed on a spinning rod, and the time to fall off was measured. Those treated with fluoxetine received a single dose of 5 mg/kg via intraperitoneal injection immediately after injury.

RESULTS

Traumatic brain injury was associated with an increase in intestinal permeability to FITC-dextran, increased lung vascular permeability, and worse performance on the rota-rod. Fluoxetine significantly reduced lung and intestinal permeability after TBI and improved performance on the rota-rod after TBI.

CONCLUSION

Use of fluoxetine has the potential to reduce lung injury and improve motor coordination in severe TBI patients. Further study will be needed to elucidate the mechanism behind this effect.

Treatment and Rehabilitation for Traumatic Brain Injury: Current Update

Traumatic brain injury (TBI) is an acquired injury to the brain caused by external mechanical forces, which can cause temporary or permanent disability. TBI and its potential long-term consequences are serious public health concerns. This review seeks to provide updated information on the current methods of management of patients with TBI to improve patient care.

Effectiveness of a guideline implementation tool for supporting management of mental health complications after mild traumatic brain injury in primary care: protocol for a randomised controlled trial

INTRODUCTION

Mental health problems frequently interfere with recovery from mild traumatic brain injury (mTBI) but are under-recognised and undertreated. Consistent implementation of clinical practice guidelines for proactive detection and treatment of mental health complications after mTBI will require evidence-based knowledge translation strategies. This study aims to determine if a guideline implementation tool can reduce the risk of mental health complications following mTBI. If effective, our guideline implementation tool could be readily scaled up and/or adapted to other healthcare settings.

METHODS AND ANALYSIS

We will conduct a triple-blind cluster randomised trial to evaluate a clinical practice guideline implementation tool designed to support proactive management of mental health complications after mTBI in primary care. We will recruit 535 adults (aged 18-69 years) with mTBI from six emergency departments and two urgent care centres in the Greater Vancouver Area, Canada. Upon enrolment at 2 weeks post-injury, they will complete mental health symptom screening tools and designate a general practitioner (GP) or primary care clinic where they plan to seek follow-up care. Primary care clinics will be randomised into one of two arms. In the guideline implementation tool arm, GPs will receive actionable mental health screening test results tailored to their patient and their patients will receive written education about mental health problems after mTBI and treatment options. In the usual care control arm, GPs and their patients will receive generic information about mTBI. Patient participants will complete outcome measures remotely at 2, 12 and 26 weeks post-injury. The primary outcome is rate of new or worsened mood, anxiety or trauma-related disorder on the Mini International Neuropsychiatric Interview at 26 weeks.

ETHICS AND DISSEMINATION

Study procedures were approved by the University of British Columbia's research ethics board (H20-00562). The primary report for the trial results will be published in a peer-reviewed journal. Our knowledge user team members (patients, GPs, policymakers) will co-create a plan for public dissemination.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04704037).

Effectiveness of Pharmacotherapy for Depression after Adult Traumatic Brain Injury: an Umbrella Review

Symptoms of depression are common following traumatic brain injury (TBI), impacting survivors' ability to return to work, participate in leisure activities, and placing strain on relationships. Depression symptoms post TBI are often managed with pharmacotherapy, however, there is little research evidence to guide clinical practice. There have been a number of recent systematic reviews examining pharmacotherapy for post TBI depression. The aim of this umbrella review was to synthesize systematic reviews and meta-analyses of the effectiveness of pharmacotherapy for the management of post TBI depression in adults. Eligible reviews examined any pharmacotherapy against any comparators, for the treatment of depression in adults who had sustained TBI. Seven databases were searched, with additional searching of online journals, Research Gate, Google Scholar and the TRIP Medical Database to identify published and unpublished systematic reviews and meta-analyses in English up to May 2020. A systematic review of primary studies available between March 2018 and May 2020 was also conducted. Evidence quality was assessed using Joanna Briggs Institute Critical Appraisal Instruments. The results are presented as a narrative synthesis. Twenty-two systematic reviews were identified, of which ten reviews contained a meta-analysis. No new primary studies were identified in the systematic review. There was insufficient high quality and methodologically rigorous evidence to recommend prescribing any specific drug or drug class for post TBI depression. The findings do show, however, that depression post TBI is responsive to pharmacotherapy in at least some individuals. Recommendations for primary studies, systematic reviews and advice for prescribers is provided. Review Registration PROSPERO (CRD42020184915).

Development of RehaBot-A Conversational Agent for Promoting Rewarding Activities in Users With Traumatic Brain Injury

OBJECTIVE

In this article, we describe the development and preliminary testing of RehaBot-a chatbot that users communicate with via text messaging designed to augment behavioral activation (BA) treatment of reducing depression and increasing participation in individuals with moderate to severe traumatic brain injury (TBI).

SETTING

Outpatient brain injury rehabilitation facility.

PARTICIPANTS

Outpatient brain injury clinicians and individuals with moderate to severe TBI.

DESIGN

Focus groups, software demonstration trials, and single-case experiments with an A-B-A design.

MAIN MEASURES

System Usability Scale (SUS) and self-reported completed target activities.

RESULTS

Focus group feedback guided the development of a flexible system to be used in conjunction with face-to-face therapy, designed to provide reminders, encouragement, and supportive feedback. Two of 3 participants completed all 6 RehaBot tasks independently. One completed 4 tasks independently and a fifth with assistance. Average SUS score in demonstration trials was 76.77 (SD = 21.19). In 4 single-case experiments, participants completed their highest proportion of planned activities in the RehaBot phase and the lowest proportion of planned activities in the reversal phase. They all interacted with RehaBot daily, exchanging an average of 225 messages over the 1-week period, and average SUS score was 95 (SD = 4.74). Their open-ended feedback revealed that participants found RehaBot enjoyable and easy to use. They felt it was a helpful memory aid and promoted better adherence to planned activities by providing accountability and positive reinforcement.

CONCLUSIONS

This article presents a chatbot development process heavily involving consumer input, which may serve as a model for future development efforts. Our findings provide preliminary evidence suggesting that RehaBot is usable and may promote better adherence to planned target activities. However, future research is needed to establish usability and efficacy of RehaBot and to explore applications of chatbots to other domains of TBI rehabilitation.

Long-term outcome after severe traumatic brain injury: a systematic literature review

BACKGROUND

Expectation of long-term outcome is an important factor in treatment decision-making after severe traumatic brain injury (sTBI). Conclusive long-term outcome data substantiating these decisions is nowadays lacking. This systematic review aimed to provide an overview of the scientific literature on long-term outcome after sTBI.

METHODS

A systematic search was conducted using PubMed from 2008 to 2020. Studies were included when reporting long-term outcome ≥ 2 years after sTBI (GCS 3-8 or AIS head score ≥ 4), using standardized outcome measures. Study quality and risk of bias were assessed using the QUIPS tool.

RESULTS

Twenty observational studies were included. Studies showed substantial variation in study objectives and study methodology. GOS-E (n = 12) and GOS (n = 8) were the most frequently used outcome measures. Mortality was reported in 46% of patients (range 18-75%). Unfavourable outcome rates ranged from 29 to 100% and full recovery was seen in 21-27% of patients. Most surviving patients reported SF-36 scores lower than the general population.

CONCLUSION

Literature on long-term outcome after sTBI was limited and heterogeneous. Mortality and unfavourable outcome rates were high and persisting sequelae on multiple domains common. Nonetheless, a considerable proportion of survivors achieved favourable outcome. Future studies should incorporate standardized multidimensional and temporal long-term outcome measures to strengthen the evidence-base for acute and subacute decision-making.

HIGHLIGHTS

1. Expectation of long-term outcome is an important factor in treatment decision-making for patients with severe traumatic brain injury (sTBI). 2. Favourable outcome and full recovery after sTBI are possible, but mortality and unfavourable outcome rates are high. 3. sTBI survivors are likely to suffer from a wide range of long-term consequences, underscoring the need for long-term and multi-modality outcome assessment in future studies. 4. The quality of the scientific literature on long-term outcome after sTBI can and should be improved to advance treatment decision-making.

Treatment of Psychiatric Problems After Traumatic Brain Injury

Psychiatric sequelae of traumatic brain injury (TBI) can cause significant and often chronic impairment in functioning and quality of life; however, their phenomenological and mechanistic complexities continue to present significant treatment challenges. The clinical presentation is often an amalgam of syndromes and co-occurring symptoms that require a highly nuanced and systematic approach to treatment. Although few randomized controlled trials have tested treatments for psychiatric problems after TBI and the synthesis of results continues to be compromised by the heterogeneity of study populations, small samples, and differing inclusion criteria and outcome measures, an increasing body of literature supports evidence-based treatment strategies. We provide a narrative review of pharmacological, psychoeducational/behavioral, and neuromodulation treatments for psychiatric conditions in adults with TBI and discuss known or postulated mechanisms of action for these treatment approaches. Where data are available, we focus on randomized controlled trials and large case series in which a psychiatric condition provides both a selection criterion and a primary or secondary outcome. We conclude by proposing directions for future research, particularly the need for novel neuropharmacological, behavioral, and neurophysiological studies and pragmatic trials of multicomponent and adaptive models that will increase understanding of the mechanisms underlying post-TBI psychiatric disorders and accelerate dissemination and implementation of effective person-centered care.

Neurological Symptoms and Their Associations With Inflammatory Biomarkers in the Chronic Phase Following Traumatic Brain Injuries

BACKGROUND

The underlying biological mechanisms for neurological symptoms following a traumatic brain injury (TBI) remain poorly understood. This study investigated the associations between serum inflammatory biomarkers and neurological symptoms in the chronic phase following moderate to severe TBI.

METHODS

The serum interleukin [IL]-1β, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, and the tumor necrosis factor [TNF]-α in 72 TBI patients 6 months to 2 years post injury were measured. Neurological symptoms including depression, chronic headache, sleep disturbance, irritability, anxiety, and global neurological disability was assessed. The associations between the biomarkers and the neurological symptoms were assessed using correlation and regression analysis.

RESULTS

It was found that the most common post-injury symptom was sleep disturbance (84.7%), followed by chronic headaches (59.7%), irritability (55.6%), and depression (54.2%). TNF-α was a protective factor for chronic headache (OR = 0.473, 95% CI = 0.235-0.952). IL-6 was positively associated with sleep disturbance (r = 0.274, p = 0.021), while IL-5 and IL-12p70 were negatively associated with the degree of global neurological disability (r = -0.325, p = 0.006; r = -0.319, p = 0.007).

CONCLUSION

This study provides preliminary evidence for the association between chronic inflammation with neurological symptoms following a TBI, which suggests that anti-inflammatory could be a potential target for post-TBI neurological rehabilitation. Further research with larger sample sizes and more related biomarkers are still needed, however, to elucidate the inflammatory mechanisms for this association.

Neuroimaging correlates of syndromal depression following traumatic brain injury: A systematic review of the literature

Objective

To complete a systematic review of the literature examining neuroimaging findings unique to co-occurring syndromal depression in the setting of TBI.

Methods

A PRISMA compliant literature search was conducted in PubMed (MEDLINE), PsychINFO, EMBASE, and Scopus databases for articles published prior to April of 2022. The database query yielded 4447 unique articles. These articles were narrowed based on specific inclusion criteria (e.g., clear TBI definition, clear depression construct commenting on the syndrome of major depressive disorder, conducted empirical analyses comparing neuroimaging correlates in TBI subjects with depression versus TBI subjects without depression, controlled for the time interval between TBI occurrence and acquisition of neuroimaging).

Results

A final cohort of 10 articles resulted, comprising the findings from 423 civilians with brain injury, 129 of which developed post-TBI depression. Four articles studied mild TBI, three mild/moderate, one moderate/severe, and two all-comers, with nine articles focusing on single TBI and one including both single and recurrent injuries. Spatially convergent structural abnormalities in individuals with TBI and co-occurring syndromal depression were identified primarily in bilateral frontal regions, particularly in those with damage to the left frontal lobe and prefrontal cortices, as well as temporal regions including bilateral temporal lobes, the left superior temporal gyrus, and bilateral hippocampi. Various parietal regions and the nucleus accumbens were also implicated. EEG studies showed supporting evidence of functional changes in frontal regions.

Conclusion

Additional inquiry with attention to TBI without depression control groups, consistent TBI definitions, previous TBI, clinically diagnosed syndromal depression, imaging timing post-injury, acute prospective design, functional neuroimaging, and well-defined neuroanatomical regions of interest is crucial to extrapolating finer discrepancies between primary and TBI-related depression.

Relations among Suicidal Ideation, Depressive Symptoms, and Functional Independence during the Ten Years after Traumatic Brain Injury: A Model Systems Study

OBJECTIVE

To investigate relative causality in relations among suicidal ideation (SI), depressive symptoms, and functional independence over the first 10 years after traumatic brain injury (TBI).

DESIGN

Prospective longitudinal design with data collected through the TBI Model Systems (TBIMS) network at acute rehabilitation hospitalization, as well as 1, 2, 5, and 10 years after injury.

SETTING

United States Level I/II trauma centers and inpatient rehabilitation centers with telephone follow-up.

PARTICIPANTS

Individuals enrolled into the TBIMS National Database (N=9539) with at least one SI score at any follow-up data collection (72.1% male, mean age = 39.39 years).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Patient Health Questionnaire-9 and Functional Independence Measure at years 1, 2, 5, and 10 post-injury.

RESULTS

A cross-lagged panel structural equation model (SEM), which is meant to indirectly infer causality through longitudinal correlational data, suggested that SI, depressive symptoms, and functional independence each significantly predicted themselves over time. Within the model, bivariate correlations among variables were all significant within each time point. Between years 1 and 2 and between years 2 and 5, depressive symptoms had a larger effect on SI than SI had on depressive symptoms. Between years 5 and 10, there was reciprocal causality between the two variables. Functional independence more strongly predicted depressive symptoms than the reverse between years 1 and 2 as well as years 2 and 5, but its unique effects on SI over time were extremely marginal or absent after controlling for depressive symptoms.

CONCLUSIONS

A primary goal for rehabilitation and mental health providers should be to monitor and address elevated symptoms of depression as quickly as possible before they translate into SI, particularly for individuals with TBI who have reduced functional independence. Doing so may be a key to breaking the connection between low functional independence and SI.

Pharmacotherapy for Treatment of Cognitive and Neuropsychiatric Symptoms After mTBI

OBJECTIVES

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

METHODS

Review of the literature.

RESULTS & CONCLUSIONS

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

Prevalence of depression and anxiety disorders following mild traumatic brain injury

BACKGROUND

Previous studies have identified an association between traumatic brain injuries and the development of psychiatric disorders in general. However, these studies were subject to limitations that demonstrate the need for a study of a large, clearly defined mild traumatic brain injury (mTBI) population within an integrated healthcare system.

OBJECTIVE

To determine the prevalence and relative risk of postinjury affective disorders over 4 years following mTBI.

DESIGN

Cohort study of mTBI cases and matched controls, over a 4-year period.

SETTING

An integrated healthcare delivery system in California.

PATIENTS

A total of 9428 adult health plan members diagnosed with mTBI from 2000-2007 and enrolled in the year before injury, during which no TBI was ascertained. Control participants included 18,856 individuals selected based on the following criteria: Two unexposed health plan members per each mTBI-exposed patient were randomly selected and individually matched for age, gender, race/ethnicity, and medical comorbidities.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

A diagnosis of affective disorder (depressive, anxiety, and adjustment disorders) in the 4 years after mTBI or the reference date, determined according to the International Classification of Diseases, Ninth Revision, Clinical Modification as well as the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision.

RESULTS

Affective disorders were most prominent during the first 12 months with 23% following mTBI and 14% in the control group. Four-year aggregate adjusted odds ratios for having an affective disorder following mTBI were 1.2 (95% CI: 1.1, 1.2; p < .001) and 1.5 (95% CI: 1.5, 1.6; p < .001) for patients with and without prior affective disorders, respectively.

CONCLUSION

mTBI was associated with a significantly increased risk of having subsequent affective disorders. Screening for and addressing affective disorders at earlier stages following the injury is an important step to avoid persisting conditions that may pose a barrier to full recovery.

Oral Administration of Brain Protein Combined With Probiotics Induces Immune Tolerance Through the Tryptophan Pathway

Excessive inflammation leads to secondary immune damage after traumatic brain injury (TBI). The intestinal mucosa is a key component of immune tolerance due to gut-brain axis regulation, but the curative effect is not optimal. Intestinal dysfunction impairs the establishment of immune tolerance in patients with TBI. Therefore, we orally administered brain protein (BP) combined with probiotics to induce immune tolerance and explored the mechanism by which the homeostasis of the microbiota contributes to the enhancement of curative effects by BPs. Herein, we demonstrated that patients with TBI and surgical brain injury (SBI) models of rats had obvious dysbiosis. Notably, the intestinal barrier, proinflammatory cytokines, and activation of microglia demonstrated that excessive inflammatory damage was better controlled in the combined group (oral administration of BP combined with probiotics) than in the BP group (oral administration of BP). Fundamentally, tandem mass tag (TMT)-based quantitative proteomics analysis revealed that BP and probiotics preferentially affect Try-related pathways. A series of experiments further confirmed that Indoleamine 2,3 dioxygenase (IDO)/Kynurenine (Kyn)/Aryl hydrocarbon receptor (AhR) expression was high in the BP group, while Tryptophan hydroxylase 1(TpH1)/5-hydroxytryptamine (5-HT) only changed in the combined group. This study suggests that probiotics can enhance the efficacy of oral BP-induced immune tolerance through the Try pathway.

Patient Attribution of Posttraumatic Symptoms to Brain Injury Versus PTSD in Military-Related Mild TBI

OBJECTIVE

Persistent cognitive, somatic, and neuropsychiatric symptoms following mild traumatic brain injury (TBI) are influenced by posttraumatic stress disorder (PTSD), particularly in military patients. The authors evaluated the degree to which military service members with a history of mild TBI attributed posttraumatic symptoms to TBI versus PTSD.

METHODS

Service members (N=372) with mild TBI were surveyed about the severity of posttraumatic symptoms across four symptom clusters (cognitive, affective, somatosensory, and vestibular) with the Neurobehavioral Symptom Inventory (NSI). Participants rated the degree to which they believed TBI, PTSD, or other conditions contributed to their symptoms. Differences in cognitive, affective, somatosensory, and vestibular symptom severity were evaluated across participants with TBI, PTSD, or combined TBI-PTSD attribution. Logistic regression was used to evaluate the association between symptom profiles and attribution.

RESULTS

Participants attributed symptoms mostly to TBI, followed by insufficient sleep, PTSD, chronic pain, depression, and deployment-readjustment stress. PTSD and combined TBI-PTSD attribution were associated with higher total NSI scores (39.5 and 51.6, respectively), compared with TBI attribution only (31.4) (F=29.08, df=3, 358, p<0.01), as well as higher scores in every symptom category. More severe affective symptoms were associated with decreased odds of TBI attribution (odds ratio=0.90, 95% CI=0.83-0.97) and increased odds of PTSD attribution (odds ratio=1.14, 95% CI=1.03-1.26). A PTSD diagnosis was highly associated with PTSD attribution (odds ratio=2.44, 95% CI=1.07-5.58).

CONCLUSIONS

The nature and severity of posttraumatic symptoms appear to play a role in patient beliefs about the causes of symptoms, whether from TBI or PTSD.

Integrated neuropsychological and cognitive behavioural therapy after acquired brain injury: A pragmatic randomized clinical trial

After acquired brain injury (ABI) many patients suffer from persistent cognitive and emotional disturbances. The aim of this study was to investigate the treatment outcome of an integrated intervention, combining neuropsychological and cognitive behavioural therapy (nCBT), against waitlist (WL) in outpatients with ABI. Individuals seeking outpatient treatment for cognitive and emotional problems after ABI were randomly allocated to nCBT (n = 27) or WL (n = 29) and completed assessments at baseline, post-treatment/WL and at six-month follow-up. The primary outcome measures were general psychopathology and functional activity in daily life. The nCBT group showed significant improvement for general psychopathology post-treatment when compared to WL. nCBT was also superior to WL regarding the secondary outcomes, i.e., the reduction of negative affect and the improvement of quality of life. No significant differences for functional activity and community integration were observed. Significant pre-post effect sizes ranged between small for functional activity and medium for quality of life. The positive effects were maintained at follow-up. The majority of patients with cognitive and emotional problems after ABI benefit from an integrated approach that offers cognitive remediation and psychotherapy. However, the heterogeneous sequelae of ABI and the moderate sample sizes in clinical trials present a methodological challenge to ABI research.

Representation in rehabilitation research of adults with traumatic brain injury and depression: A scoping review

Objective: To determine how well comorbid depression is described, defined, and measured in the rehabilitation literature that pertains to TBI and depression.Method: Scoping review of the rehabilitation sciences literature. Six databases were searched (to October 17, 2018) using the three core concepts of TBI, depression, and rehabilitation, as was for gray literature. Two independent reviewers reviewed documents for eligibility.Results: 3737 records were reviewed and 137 documents were analyzed. Primary studies (n = 126) were most prevalent and of quantitative descriptive design (n = 102). The number of participants with TBI and comorbid depression could only be determined for 81/126 (64%) of primary studies, in which they are the minority (median of 30% of sample). Depression reporting was heterogeneous and individuals with TBI and depression were not analyzed as a subgroup in most studies (n = 68, 55%). Depression self-report instruments are commonly used (14 instruments used in 111 studies). Few studies (n = 14, 19%) have participant samples with discrete severity levels of TBI and depression.Conclusions: Better participant representation and reporting of TBI and depression variables are needed to enhance comparability across studies and improve rehabilitation outcomes.

Pre-existing mental health disorders in patients admitted to the intensive care unit: A systematic review and meta-analysis of prevalence

AIMS

To determine the reported prevalence rate of pre-existing mental health disorders in patients admitted to adult ICUs and identify the most commonly occurring types of these disorders.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Five electronic databases were searched from 1 January 2000 -15 April 2020. Google Scholar was used to perform forwards citation searching.

METHODS

This review was conducted in line with the PRISMA guidelines and protocol registered with PROSPERO CRD42020181818. Meta-analyses were performed using the quality effects model to calculate weighted pooled prevalence estimates and heterogeneity was tested using the I² statistic.

RESULTS

Seven articles were included in the final review and meta-analysis (143,179 participants). Identified prevalence rates varied considerably, ranging from 6.2-28.0%, reflecting variation in each study's clinical context, as well as different patient selection and identification methodologies. The pooled prevalence rate of all pre-existing mental health disorders was 19.4% (95% CI 8.9-32.6%). Depression was the most common subtype, accounting for an estimated 60.5% (95% CI 54.4-66.5%) of identified mental health disorders. All analyses showed significant heterogeneity with I²  > 95%.

CONCLUSION

Approximately 19% of adult ICU patients have a history of a mental health disorder, most commonly depression. Further research is needed to improve the accuracy of this estimate as well as determine the best identification method.

IMPACT

This study has demonstrated that patients with pre-existing mental health disorders, particularly depression, constitute a significant subgroup in ICU. Given that the presence of a pre-existing mental health disorder appears to confer an increased mortality risk following ICU discharge, clinicians need to be made aware of this group of patients to provide additional support. Further research is needed to more accurately quantify this vulnerable group and establish methods to enable clinicians to readily identify and refer these patients for appropriate follow-up treatment.

Part 2: Bypassing TBI-Metabolic Surgery and the Link Between Obesity and Traumatic Brain Injury-A Review

Obesity is a common outcome of traumatic brain injury (TBI) that exacerbates principal TBI symptom domains identified as common areas of post-TBI long-term dysfunction. Obesity is also associated with increased risk of later-life dementia and Alzheimer's disease. Patients with obesity and chronic TBI may be more vulnerable to long-term mental abnormalities. This review explores the question of whether weight loss induced by bariatric surgery could delay or perhaps even reverse the progression of mental deterioration. Bariatric surgery, with its induction of weight loss, remission of type 2 diabetes, and other expressions of the metabolic syndrome, improves metabolic efficiency, leads to reversal of brain lesions seen on imaging studies, and improves function. These observations suggest that metabolic/bariatric surgery may be the most effective therapy for TBI.

Hemispheric stroke: Mood disorders

Stroke causes many forms of disability, including emotional and mood disorders. Depression is the most common of these, affecting approximately one-third of stroke patients. Other disorders like mania, bipolar disorder, anxiety disorder, or apathy may also develop following stroke, although they are less common. The development of mood and emotional disorders is dependent on the severity of brain injury, the side of injury, and hemispheric location. Whereas a left hemispheric stroke often results in depression or a catastrophic reaction with anxiety, injury to the right hemisphere has predominantly been associated with the development of emotional indifference (anosodiaphoria) or euphoria. In this chapter, we discuss the mood disorders associated with hemispheric strokes and the neuropsychological mechanisms that might account for the clinical manifestations of these affective disorders.

Evaluating the Cross-Sectional and Longitudinal Relationships Predicting Suicidal Ideation Following Traumatic Brain Injury

OBJECTIVE

Characterize relationships among substance misuse, depression, employment, and suicidal ideation (SI) following moderate to severe traumatic brain injury (TBI).

DESIGN

Prospective cohort study.

SETTING

Inpatient rehabilitation centers with telephone follow-up; level I/II trauma centers in the United States.

PARTICIPANTS

Individuals with moderate to severe TBI with data in both the National Trauma Data Bank and the Traumatic Brain Injury Model Systems National Database, aged 18 to 59 years, with SI data at year 1 or year 2 postinjury (N = 1377).

MAIN OUTCOME MEASURE

Primary outcome of SI, with secondary employment, substance misuse, and depression outcomes at years 1 and 2 postinjury.

RESULTS

Cross-lagged structural equation modeling analysis showed that year 1 unemployment and substance misuse were associated with a higher prevalence of year 1 depression. Depression was associated with concurrent SI at years 1 and 2. Older adults and women had a greater likelihood of year 1 depression. More severe overall injury (injury severity score) was associated with a greater likelihood of year 1 SI, and year 1 SI was associated with a greater likelihood of year 2 SI.

CONCLUSIONS

Substance misuse, unemployment, depression, and greater extracranial injury burden independently contributed to year 1 SI; in turn, year 1 SI and year 2 depression contributed to year 2 SI. Older age and female sex were associated with year 1 depression. Understanding and mitigating these risk factors are crucial for effectively managing post-TBI SI to prevent postinjury suicide.