Epidemiology of traumatic brain injury

Traumatic brain injury persistently increases the incidence of both ischemic and hemorrhagic strokes: Potential mechanisms

Traumatic brain injuries (TBI) significantly increase the risk of both ischemic and hemorrhagic strokes, with effects persisting for years after the initial injury. The mechanisms underlying this increased stroke risk are complex, multifactorial, and incompletely understood but likely include chronic cerebrovascular dysfunction, blood-brain barrier disruption, and inflammatory responses. Epidemiological studies consistently show that TBI is an independent risk factor for stroke, with more severe injuries associated with greater risk, especially for hemorrhagic strokes. Traditional risk factors for stroke, such as hypertension, poor diet, and sedentary lifestyle, further elevate the risk in TBI survivors. Modifiable lifestyle factors, such as improving sleep, increasing physical activity, and adopting heart-healthy diets, offer potential intervention points to mitigate stroke risk. Pharmacological considerations, including the use of antidepressants, anticoagulants, and statins, also influence stroke risk, particularly with regard to hemorrhagic complications. This review explores the pathophysiological mechanisms linking TBI and stroke, emphasizing the need for future research to identify specific biomarkers and imaging techniques to predict stroke vulnerability in TBI patients. Addressing the gaps in understanding, particularly regarding small vessel pathology, will be essential to developing targeted therapies for reducing stroke incidence in TBI survivors.

Diffuse traumatic brain injury induced stimulator of interferons (STING) signaling in microglia drives cortical neuroinflammation, neuronal dysfunction, and impaired cognition

Neuropsychiatric complications including depression and cognitive impairment develop, persist, and worsen in the years after traumatic brain injury (TBI), negatively affecting life and lifespan. Inflammatory responses mediated by microglia are associated with the transition from acute to chronic neuroinflammation after TBI. Moreover, type I interferon (IFN-I) signaling is a key mediator of inflammation during this transition. Thus, the purpose of this study was to determine the degree to which a microglia-specific knockout of the stimulator of interferons (STING) influenced TBI-induced neuroinflammation, neuronal dysfunction, and cognitive impairment. Here, microglial inducible STING knockout (CX₃CR1Cre/ERT2 x STINGfl/fl) mice were created and validated (mSTING-/-). Diffuse brain injury (midline fluid percussion) in male and female mice increased STING expression in microglia, promoted microglial morphological restructuring, and induced robust cortical inflammation and pathology 7 days post injury (dpi). These TBI-associated responses were attenuated in mSTING-/- mice. Increased cortical astrogliosis and rod-shaped microglia induced by TBI were independent of mSTING-/-. 7 dpi, TBI induced 237 differentially expressed genes (DEG) in the cortex of functionally wildtype (STINGfl/fl) associated with STING, NF-κB, and Interferon Alpha signaling and 85% were attenuated by mSTING-/-. Components of neuronal injury including reduced NeuN expression, increased cortical lipofuscin, and increased neurofilament light chain in plasma were increased by TBI and dependent on mSTING. TBI-associated cognitive tasks (novel object recognition/location, NOR/NOL) at 7 dpi were dependent on mSTING. Notably, the TBI-induced cognitive deficits in NOR/NOL and increased cortical inflammation 7 dpi were unaffected in global interferon-α/β receptor 1 knockout (IFNAR1) mice. In the final study, the RNA profile of neurons after TBI in STINGfl/fl and mSTING-/- mice was assessed 7 dpi by single nucleus RNA-sequencing. There was a TBI-dependent suppression of cortical neuronal homeostasis with reductions in CREB signaling, synaptogenesis, and oxytocin signaling and increases in cilium assembly and PTEN signaling. Overall, mSTING-/- prevented 50% of TBI-induced DEGs in cortical neurons. Collectively, ablation of STING in microglia attenuates TBI-induced interferon responses, cortical inflammation, neuronal dysfunction, neuronal pathology, and cognitive impairment.

Traumatic Brain Injury and Chronic Traumatic Encephalopathy: Not Only Trigger for Neurodegeneration but Also for Cerebral Amyloid Angiopathy?

Traumatic brain injury (TBI) has been linked to the development of neurodegenerative diseases, particularly Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE). This review critically assesses the relationship between TBI and cerebral amyloid angiopathy (CAA), highlighting the complexities of diagnosing CAA in the context of prior head trauma. While TBI has been shown to facilitate the accumulation of amyloid plaques and tau pathology, the interplay between neurodegenerative processes and vascular contributions remains underexplored. Epidemiological studies indicate that TBI increases the risk of various dementias, not solely AD, emphasizing the need for a comprehensive understanding of TBI-related neurodegeneration as a polypathological condition. This review further delineates the mechanisms by which TBI can lead to CAA, particularly focusing on the vascular changes that occur post-injury. It discusses the challenges associated with diagnosing CAA after TBI, particularly due to the overlapping symptoms and pathologies that complicate clinical evaluations. Notably, this review includes a clinical case that exemplifies the diagnostic challenges posed by TBI in patients with subsequent cognitive decline and vascular pathology. By synthesizing current research on TBI, CAA, and associated neurodegenerative conditions, this review aims to foster a more nuanced understanding of how these conditions interact and contribute to long-term cognitive outcomes. The findings underscore the importance of developing standardized diagnostic criteria and imaging techniques to better elucidate the relationship between TBI and vascular pathology, which could enhance clinical interventions and inform therapeutic strategies for affected individuals.

The role of isolated diffuse axonal brain injury on post-traumatic depressive- and anxiety-like behavior in rats

Traumatic brain injury (TBI) is a significant global health concern and is associated with short-term and long-term comorbidities such as mood disorders and reduced quality of life. Diffuse axonal brain injury (DABI) is a common but severe type of TBI. The role of DABI in the development of psychiatric sequelae after TBI is not well understood due to the challenge of isolating DABI from general TBI in the human population. Here we investigate the role of DABI in the occurrence of post-TBI depressive- and anxiety-like behaviors in a rat model. Forty rats were randomly assigned to two groups, with 20 receiving DABI and 20 receiving sham treatment. We used a magnetic resonance imaging (MRI) protocol developed for DABI using a 3-T clinical scanner to confirm DABI. We then compared neuroimaging, neurological and behavioral assessments across experimental groups. There was a significant difference between DABI and sham groups on sucrose preference, a measurement of depressive-like behavior (p < 0.012), and time spent on open arms on a plus maze test, a measurement of anxiety-like behavior (p < 0.032). For MRI-detected injury, there was a difference in diffusion-weighted imaging with relative anisotropy (p < 0.001) and fractional anisotropy (p < 0.001) mapping. We found that isolated DABI in our model led to post-traumatic depressive-like behavior in 30% of cases and anxiety-like behavior in 35%. Additionally, we established diagnostic cut-offs for depressive-like and anxiety-like behaviors in injured rats. We also documented comorbidity between the development of depression and anxiety in DABI-exposed rats. We anticipate that this study will greatly enhance the understanding of the relationship between DABI, TBI, and mood disorders like depression and anxiety, and aid in developing treatment options for these interconnected conditions.

Therapeutic effect of memantine on patients with posttraumatic headache: A randomized double-blinded clinical trial

Background

Traumatic brain injury (TBI) can result in different complications. Posttraumatic headache (PTH) is a disabling complication of TBI. We investigated the therapeutic effect of memantine on patients with PTH.

Materials and Methods

This randomized and double-blinded clinical trial was performed in 2020 in a hospital on 90 patients with head trauma. Patients were divided into two groups. The active group received 5 mg memantine tablet for 2 weeks followed by 10 mg tablet daily for up to 6 months. The control arm received identical placebo tablets. Patients were evaluated at 3 months and 6 months. Headache severity was measured with a Visual Analog Scale for Pain. Headache frequency (per week) and duration were also recorded.

Results

After 3 months, the patients in the memantine group had significantly lower headache severity (P = 001) and frequency (P = 0.008) in comparison to baseline of the study. However, in the placebo group, there was only significant reduction in the headache duration (P = 0.001), and there was no significant reduction in headache intensity and frequency. After 6 months, there was a significant reduction in headache intensity and duration in both groups (P < 0.05), but only in the memantine group, headache frequency was significantly reduced (P < 0.001). Finally, patients in the memantine group had less headache intensity, frequency, and duration after 6 months of taking memantin than the placebo group.(P < 0.05 for all).

Conclusion

The administration of memantine for 6 months could significantly lower the severity, duration, and frequency of PTHs.

Nasal anti-CD3 monoclonal antibody ameliorates traumatic brain injury, enhances microglial phagocytosis and reduces neuroinflammation via IL-10-dependent Treg-microglia crosstalk

Neuroinflammation plays a crucial role in traumatic brain injury (TBI), contributing to both damage and recovery, yet no effective therapy exists to mitigate central nervous system (CNS) injury and promote recovery after TBI. In the present study, we found that nasal administration of an anti-CD3 monoclonal antibody ameliorated CNS damage and behavioral deficits in a mouse model of contusional TBI. Nasal anti-CD3 induced a population of interleukin (IL)-10-producing regulatory T cells (Treg cells) that migrated to the brain and closely contacted microglia. Treg cells directly reduced chronic microglia inflammation and regulated their phagocytic function in an IL-10-dependent manner. Blocking the IL-10 receptor globally or specifically on microglia in vivo abrogated the beneficial effects of nasal anti-CD3. However, the adoptive transfer of IL-10-producing Treg cells to TBI-injured mice restored these beneficial effects by enhancing microglial phagocytic capacity and reducing microglia-induced neuroinflammation. These findings suggest that nasal anti-CD3 represents a promising new therapeutic approach for treating TBI and potentially other forms of acute brain injury.

Repetitive concussions promote microglia-mediated engulfment of presynaptic excitatory input associated with cognitive dysfunction

Concussions are a current health concern and account for the vast majority of head trauma. While symptoms after a single impact are usually transient, repetitive concussions, as often occur in sports, are responsible for persistent acute and chronic deficits. Here, we used a model of bilateral midline-centered concussions in mice to show that repetitive concussions selectively induce impairments in learning ability compared to single-impact injuries. Since microglial cells and their activation are considered key factors in degenerative pathology after brain trauma, we examined their structure and function after single and repetitive concussions in the cortex underlying the concussions and in the hippocampus. We found that only repetitive concussions led to a significant long-lasting structural activation of microglia and an increase in microglia-mediated engulfment of presynaptic excitatory synapses, while the elimination of inhibitory synapses was not altered. Since the density of excitatory input did not change during the 6-week study period, we hypothesize that there is a turnover of excitatory synapses following repetitive concussion that can be compensated for, anatomically but not behaviorally.

Machine learning using random forest to differentiate between blow and fall situations of head trauma

Blunt head trauma is a common occurrence in forensic practice. Interpreting the origin of craniocerebral injuries can be a challenging process, particularly when it comes to distinguishing between falls or inflicted blows. The objective of this study was to develop a predictive model using an innovative Random Forest (RF) classification approach to differentiate injuries caused by falls from those caused by blows. The study examined 65 cases of blunt head trauma over the age of 18 resulting from a fall or an inflicted blow. A preliminary univariate logistic regression analysis followed by RF classification was performed. The presence of a depressed fracture and the lateralisation on the left-sided of cranial vault fractures, as well as extra-axial bleeding, in particular an extra-dural haematoma, were indicative of inflicted blows. The RF classification provided a simple predictive model with an accuracy rate of 78% to identify the most relevant injury criteria for distinguishing between falls and assault situations involving blows.

Diffuse Traumatic Brain Injury Induced Stimulator of Interferons (STING) Signaling in Microglia Drives Cortical Neuroinflammation, Neuronal Dysfunction, and Impaired Cognition

Neuropsychiatric complications including depression and cognitive impairment develop, persist, and worsen in the years after traumatic brain injury (TBI), negatively affecting life and lifespan. Inflammatory responses mediated by microglia are associated with the transition from acute to chronic neuroinflammation after TBI. Moreover, type I interferon (IFN-I) signaling is a key mediator of inflammation during this transition. Thus, the purpose of this study was to determine the degree to which a microglia-specific knockout of the stimulator of interferons (STING) influenced TBI-induced neuroinflammation, neuronal dysfunction, and cognitive impairment. Here, microglial inducible STING knockout (CX₃CR1Cre/ERT2 x STING fl/fl ) mice were created and validated (mSTING -/- ). Diffuse brain injury (midline fluid percussion) in male and female mice increased STING expression in microglia, promoted microglial morphological restructuring, and induced robust cortical inflammation and pathology 7 days post injury (dpi). These TBI-associated responses were attenuated in mSTING -/- mice. Increased cortical astrogliosis and rod-shaped microglia induced by TBI were independent of mSTING -/- . 7 dpi, TBI induced 237 differentially expressed genes (DEG) in the cortex of functionally wildtype (STING +/+ ) associated with STING, NF- κB, and Interferon Alpha signaling and 85% were attenuated by mSTING -/- . Components of neuronal injury including reduced NeuN expression, increased cortical lipofuscin, and increased neurofilament light chain in plasma were increased by TBI and dependent on mSTING. TBI-associated cognitive tasks (novel object recognition/location, NOR/NOL) at 7 dpi were dependent on mSTING. Notably, the TBI-induced cognitive deficits in NOR/NOL and increased cortical inflammation 7 dpi were unaffected in global interferon-α/β receptor 1 knockout (IFNAR1) mice. In the final study, the RNA profile of neurons after TBI in STING +/+ and mSTING -/- mice was assessed 7 dpi by single nucleus RNA-sequencing. There was a TBI-dependent suppression of cortical neuronal homeostasis with reductions in CREB signaling, synaptogenesis, and oxytocin signaling and increases in cilium assembly and PTEN signaling. Overall, mSTING -/- prevented 50% of TBI-induced DEGs in cortical neurons. Collectively, ablation of STING in microglia attenuates TBI-induced IFN-dependent responses, cortical inflammation, neuronal dysfunction, neuronal pathology, and cognitive impairment.

A larval zebrafish model of traumatic brain injury: optimizing the dose of neurotrauma for discovery of treatments and aetiology

Traumatic brain injuries (TBI) are diverse with heterogeneous injury pathologies, which creates challenges for the clinical treatment and prevention of secondary pathologies such as post-traumatic epilepsy and subsequent dementias. To develop pharmacological strategies that treat TBI and prevent complications, animal models must capture the spectrum of TBI severity to better understand pathophysiological events that occur during and after injury. To address such issues, we improved upon our recent larval zebrafish TBI paradigm emphasizing titrating to different injury levels. We observed coordination between an increase in injury level and clinically relevant injury phenotypes including post-traumatic seizures (PTS) and tau aggregation. This preclinical TBI model is simple to implement, allows dosing of injury levels to model diverse pathologies, and can be scaled to medium- or high-throughput screening.

Regionally specific resting-state beta neural power predicts brain injury and symptom recovery in adolescents with concussion: a longitudinal study

Mild traumatic brain injury (mTBI) is common in adolescents. Magnetoencephalography (MEG) studies (primarily reporting on adult males) have demonstrated abnormal resting-state (RS) brain activity in mTBI. The present study sought to identify RS abnormalities in male and female adolescents with mTBI (no previous mTBI and no previous DSM-5 diagnosis) identified from an outpatient specialty care concussion program setting as a basis for evaluating potential clinical utility. Visit 1 MEG RS data were obtained from 46 adolescents with mTBI (mean age: 15.4 years, 25 females) within 4 months of a mTBI (mTBI acute to sub-acute period) as well as from 34 typically developing (TD) controls (mean age: 14.8 years; 17 females) identified from the local community. Visit 2 RS data (follow-up ∼4.3 months after Visit 1; mTBI sub-chronic period) were obtained from 36 mTBI (19 females) and 29 TD (14 females) of those participants. Source-space RS neural activity was examined from 4 to 56 Hz. Visit 1 t-tests showed that group differences were largest in the beta range (16-30 Hz; mTBI < TD), with Visit 2 whole-brain linear mixed model (LMM) analyses examining beta-band group differences as a function of Visit. A main effect of Group indicated Visit 1 and 2 beta-band group differences in midline superior frontal gyrus, right temporal pole, and right central sulcus (all mTBI < TD). The group effects were large (Cohen's d values 0.75 to 1.31). Of clinical significance in the mTBI group, a decrease in mTBI symptoms from Visit 1 to 2 was associated with an increase in beta power in 4 other brain regions. Present findings suggest that RS beta power has potential as a measure and perhaps as a mechanism of clinical recovery in adolescents with mTBI.

Neighborhood Deprivation is Associated With Hospital Length of Stay, Discharge Disposition, and Readmission Rates for Patients Who Survive Hospitalization With Traumatic Brain Injury

BACKGROUND AND OBJECTIVES

Traumatic brain injury (TBI) is a leading cause of disability in the United States. Limited research exists on the influence of area-level socioeconomic status and outcomes after TBI. This study investigated the correlation between the Area Deprivation Index (ADI) and (1) 90-day hospital readmission rates, (2) facility discharge, and (3) prolonged (≥5 days) hospital length of stay (LOS).

METHODS

Single-center retrospective review of adult (18 years or older) patients who were admitted for TBI during 2018 was performed. Patients were excluded if they were admitted for management of a chronic or subacute hematoma. We extracted relevant clinical and demographic data including sex, comorbidities, age, body mass index, smoking status, TBI mechanism, and national ADI. We categorized national ADI rankings into quartiles for analysis. Univariate, multivariate, and area under the receiver operating characteristic curve (AUROC) analyses were performed to assess the relationship between ADI and 90-day readmission, hospital LOS, and discharge disposition.

RESULTS

A total of 523 patients were included in final analysis. Patients from neighborhoods in the fourth ADI quartile were more likely to be Black ( P = .007), have a body mass index ≥30 kg/m 2 ( P = .03), have a Charlson Comorbidity Index ≥5 ( P = .004), and have sustained a penetrating TBI ( P = .01). After controlling for confounders in multivariate analyses, being from a neighborhood in the fourth ADI quartile was independently predictive of 90-day hospital readmission (odds ratio [OR]: 1.35 [1.12-1.91], P = .011) (model AUROC: 0.82), discharge to a facility (OR: 1.46 [1.09-1.78], P = .03) (model AUROC: 0.79), and prolonged hospital LOS (OR: 1.95 [1.29-2.43], P = .015) (model AUROC: 0.85).

CONCLUSION

After adjusting for confounders, including comorbidities, TBI mechanism/severity, and age, higher ADI was independently predictive of longer hospital LOS, increased risk of 90-day readmission, and nonhome discharge. These results may help establish targeted interventions to identify at-risk patients after TBI.

Molecular intersections of traumatic brain injury and Alzheimer's disease: the role of ADMSC-derived exosomes and hub genes in microglial polarization

Traumatic brain injury (TBI) is a significant contributor to global mortality and morbidity, with emerging evidence indicating a heightened risk of developing Alzheimer's disease (AD) following TBI. This study aimed to explore the molecular intersections between TBI and AD, focusing on the role of adipose mesenchymal stem cell (ADMSC)-derived exosomes and hub genes involved in microglial polarization. Transcriptome profiles from TBI (GSE58485) and AD (GSE74614) datasets were analyzed to identify differentially expressed genes (DEGs). The hub genes were validated in independent datasets (GSE180811 for TBI and GSE135999 for AD) and localized to specific cell types using single-cell RNA (scRNA) sequencing data (GSE160763 for TBI and GSE224398 for AD). Experimental validation was conducted to investigate the role of these genes in microglial polarization using cell culture and ADMSC-derived exosomes interventions. Our results identified three hub genes-Bst2, B2m, and Lgals3bp-that were upregulated in both TBI and AD, with strong associations to inflammation, neuronal apoptosis, and tissue repair processes. scRNA sequencing revealed that these genes are predominantly expressed in microglia, with increased expression during M1 polarization. Knockdown of these genes reduced M1 polarization and promoted M2 phenotype in microglia. Additionally, ADMSC-derived exosomes attenuated M1 polarization and downregulated the expression of hub genes. This study provides novel insights into the shared molecular pathways between TBI and AD, highlighting potential therapeutic targets for mitigating neuroinflammation and promoting recovery in both conditions.

Annexin-A1 tripeptide enhances functional recovery and mitigates brain damage in traumatic brain injury by inhibiting neuroinflammation and preventing ANXA1 nuclear translocation in mice

This study explores the role and mechanism of Annexin-A1 Tripeptide (ANXA1sp) in mitigating neuronal damage and promoting functional recovery in a mouse model of traumatic brain injury (TBI). Our goal is to identify ANXA1sp as a potential therapeutic drug candidate for TBI treatment. Adult male C57BL/6J mice were subjected to controlled cortical impact (CCI) to simulate TBI, supplemented by an in vitro model of glutamate-induced TBI in HT22 cells.  We assessed neurological deficits using the Modified Neurological Severity Score (mNSS), tested sensorimotor functions with beam balance and rotarod tests, and evaluated cognitive performance via the Morris water maze. Neuronal damage was quantified using Nissl and TUNEL staining, while microglial activation and inflammatory responses were measured through immunostaining, quantitative PCR (qPCR), Western blotting, and ELISA. Additionally, we evaluated cell viability in response to glutamate toxicity using the Cell Counting Kit-8 (CCK-8) assay and lactate dehydrogenase (LDH) release. Intraperitoneal administration of ANXA1sp significantly enhanced neurological outcomes, markedly reducing sensorimotor and cognitive impairments caused by TBI. This treatment resulted in a significant reduction in lesion volume and decreased neuronal cell death in the ipsilateral cortex. Moreover, ANXA1sp effectively diminished microglial activation around the brain lesion and decreased the levels of pro-inflammatory markers such as IL-6, IL-1β, TNF-α, and TGF-β in the cortex, indicating a significant reduction in neuroinflammation post-TBI. ANXA1sp also offered protection against neuronal cell death induced by glutamate toxicity, primarily by inhibiting the nuclear translocation of ANXA1, highlighting its potential as a neuroprotective strategy in TBI management. Administration of ANXA1sp significantly reduced neuroinflammation and neuronal cell death, primarily by blocking the nuclear translocation of ANXA1. This treatment substantially reduced brain damage and improved neurological functional recovery after TBI. Consequently, ANXA1sp stands out as a promising neuroprotective agent for TBI therapy.

Concussion leads to opposing sensorimotor effects of habituation deficit and fatigue in zebrafish larvae

Concussion, or mild traumatic brain injury, is caused by sudden mechanical forces impacting the brain either directly or through inertial loading. This can lead to physical, behavioural and cognitive impairments. Despite concussion being a significant health issue, our understanding of the relationship between initial impact force and the subsequent neurological consequences is not well understood. Previously, we established a model of concussion in zebrafish larvae. Here, we further investigate concussions of varying severities in zebrafish larvae using linear deceleration. Using an acoustic assay to monitor the larval sensorimotor behaviour, we found that different parameters of the resulting escape behaviour are modulated by the impact force of the preceding concussive insult. To investigate the relative contributions of habituation performance and fatigue on the escape response behaviour, we constructed a neurocomputational model. Our findings suggest that a concussive impact initially affects habituation performance at first and, as the impact force increases, fatigue is induced. Fatigue then alters the escape response behaviour in an opposing manner.

Acute and chronic hypopituitarism following traumatic brain injury: a systematic review and meta-analysis

Traumatic brain injury (TBI) is associated with various endocrine abnormalities, including pituitary axis dysfunction. Understanding the prevalence and temporal patterns of these dysfunctions is crucial for effective clinical management. This study aimed to systematically review the literature and conduct a meta-analysis to determine the prevalence of pituitary axis dysfunction following TBI, assess temporal patterns across different post-injury durations, and identify potential contributing factors. A comprehensive search was conducted across multiple electronic databases between 1st of January 2000 until 31st March 2024. Studies reporting the prevalence of pituitary axis dysfunction post-TBI were included. Pooled estimates with 95% confidence intervals (CIs) were calculated using random-effects models in the R statistical software. Subgroup analyses were performed based on duration post-TBI (< 3 months, 3-6 months, 6-12 months, > 12 months) to explore temporal variations. Heterogeneity was assessed using the I^2 statistic. A total of 52 studies were included in the meta-analysis, encompassing 7367 participants. The pooled estimate for the prevalence of any pituitary axis dysfunction post-TBI was 33% (95% CI [28%; 37%]). Subgroup analysis by duration revealed varying prevalence rates: < 3 months (40%, 95% CI [27%; 53%]), 3-6 months (31%, 95% CI [15%; 47%]), 6-12 months (26%, 95% CI [19%; 33%]), and > 12 months (32%, 95% CI [26%; 38%]). Prevalence of multiple axes affection was 7% (95% CI [6%; 9%]), with varying rates across durations. Specific axes affection varied: Growth Hormone (GH) deficiency was 18% (95% CI [14%; 21%]), adrenocorticotropic hormone (ACTH) deficiency was 10% (95% CI [8%; 13%]), pituitary-gonadal axis hormones deficiency was 16% (95% CI [12%; 19%]), and thyroid-stimulating hormone (TSH) deficiency was 6% (95% CI [5%; 7%]). This meta-analysis highlights a significant prevalence of pituitary axis dysfunction following TBI, with temporal variations observed across different post-injury durations. The findings underscore the importance of tailored clinical management strategies based on the duration and type of dysfunction. Further research addressing potential contributing factors is warranted to enhance understanding and management of these conditions.

Probiotic-based therapy as a new useful strategy for the treatment of patients with traumatic brain injury

BACKGROUND

In the new era, microbial-based medicine is one of the best strategies that try to modify the normal flora with the aim of treating some disorders. This systematic review and meta-analysis was performed to evaluate the use of probiotics in the treatment of the clinical outcomes in cases with traumatic brain injury..

METHODS

In this regard, the search strategy was done using databases such as PubMed, Embase, Scopus, CENTRAL, and Google Scholar, from 2006 until April 2024. All studies about the efficacy of probiotic supplementation on the clinical outcomes in traumatic brain injury patients were retrieved. During the assessment process of the eligible studies, we evaluated clinical characteristics such as the Glasgow Coma Scale score, the Sequential Organ Failure Assessment score, the Acute Physiology and Chronic Health Evaluation II score, referral rate and hospitalization period in the intensive care unit, mortality rate, as well as opportunistic infections in both groups of case and control..

RESULTS

In this study, the authors analyzed data from 6 articles including 391 cases with traumatic brain injury. Our results showed that the probiotic therapy increases the Glasgow Coma Scale score in patients with the average age of more than 50 years. However, there was no a significant difference in the Sequential Organ Failure Assessment and the Acute Physiology and Chronic Health Evaluation scores between the group that had received probiotics and the control group. Although probiotic-based treatment did not significantly affect the intensive care unit admission (or length of stay), but, the risk of infection, and also mortality was significantly lower in the probiotic group (OR: 0.53; 95% CI: 0.3 to 0.8, as well as OR: 0.41; 95% CI: 0.2 to 0.7, respectively)..

CONCLUSIONS

Overall, due to the modification of microbial flora, probiotic supplements can balance microflora disturbances, which in turn leads to improvement the clinical outcomes in patients with brain injury. Therefore, probiotic-based therapy can be considered as a promising strategy for the treatment of the central nervous system disorders. However, given the limited evidence, more clinical trial studies need to strengthen our results..

Neuroprotective effect of vitamin B12 supplementation on cognitive functions and neuronal morphology at different time intervals after traumatic brain injury in male Swiss albino mice

Traumatic brain injury is a highly irreversible process that consists of primary as well as secondary injury which develops and progresses over months to years, leading to cognitive dysfunctions. Vitamin B12 received considerable interest due to its potential therapeutic properties. The pathways of vitamin B12 are closely related to neuronal survival but its effects on the pathophysiology of injury with respect to cognition is a relatively unexplored area of research. In this study, we investigated, the effect of vitamin B12 and its involvement in neuroprotection on TBI-induced pathophysiology in male Swiss albino mice. Our findings suggested that vitamin B12 supplementation improves TBI-mediated neurological impairments, spatial and recognition memory, and anxiety-like behavior. Furthermore, the oxidative stress was reduced by declined homocysteine level with vitamin B12 supplementation validating declined expression of astrocytes and TBI biomarkers. The studies on neuronal morphology revealed that vitamin B12 supplementation increases the dendritic arborization and density of mushroom and filopodia-shaped spines and further increases the expression of synaptic plasticity-related genes and proteins. Taken together, our findings reveal that, supplementation of vitamin B12 restored the TBI-induced downregulation of dendritic arborization, and spine density which ultimately increases synaptic plasticity, cell survival, and recovery of cognitive dysfunctions.

Evaluation of Blood-Brain Barrier Disruption Using Low- and High-Molecular-Weight Complexes in a Single Brain Sample in a Rat Traumatic Brain Injury Model: Comparison to an Established Magnetic Resonance Imaging Technique

Traumatic brain injury (TBI), a major cause of death and disability among young people, leads to significant public health and economic challenges. Despite its frequency, treatment options remain largely unsuitable. However, examination of the blood-brain barrier (BBB) can assist with understanding the mechanisms and dynamics of brain dysfunction, which affects TBI sufferers secondarily to the injury. Here, we present a rat model of TBI focused on two standard BBB assessment markers, high- and low-molecular-weight complexes, in order to understand BBB disruption. In addition, we tested a new technique to evaluate BBB disruption on a single brain set, comparing the new technique with neuroimaging. A total of 100 Sprague-Dawley rats were separated into the following five groups: naive rats (n = 20 rats), control rats with administration (n = 20 rats), and TBI rats (n = 60 rats). Rats were assessed at different time points after the injury to measure BBB disruption using low- and high-molecular-weight complexes. Neurological severity score was evaluated at baseline and at 24 h following TBI. During the neurological exam after TBI, the rats were scanned with magnetic resonance imaging and euthanized for assessment of the BBB permeability. We found that the two markers displayed different examples of BBB disruption in the same set of brain tissues over the period of a week. Our innovative protocol for assessing BBB permeability using high- and low-molecular-weight complexes markers in a single brain set showed appropriate results. Additionally, we determined the lower limit of sensitivity, therefore demonstrating the accuracy of this method.

Navigating the Role of Surgery in Optimizing Patient Outcomes in Traumatic Brain Injuries (TBIs): A Comprehensive Review

Traumatic brain injuries (TBIs) present with symptoms ranging from a mildly altered level of consciousness to irreversible coma and death. The most severe stage of TBIs is diffuse axonal injury and swelling affecting the whole brain. Management strategies are based on the classification of TBIs by severity and type and range from cognitive therapy sessions to complex surgeries. Neuroimaging modalities, predominantly magnetic resonance imaging, and the clinical Glasgow Coma Scale are principal indicators to diagnose and assess a patient's condition and neurological status and decide optimal treatment modality. In this review, we have summarized the indications and patient outcomes based on neurological and functional status, post-surgical complications, and mortality rates for various life-saving interventional procedures including surgery for brain contusions, intracranial hematomas and penetrating injuries, and craniectomy and ventriculostomy for elevated intracranial pressure and hydrocephalus. Cranioplasty performed for aesthetic purposes has also been explored. Overall quality evidence presented advocates surgery as needed for improved patient outcomes resulting in early recovery and decreased mortality, especially with the emergence of minimally invasive techniques. However, there is still an increased risk of certain complications like infections and bleeding and severe disabilities leading to a vegetative state with surgery. Some guidelines have been formed to provide indications for optimal management of TBI patients including surgeries, although their effectiveness in each individual case is debatable. It is imperative to explore certain key areas like the timing of the surgery and the role of intensive patient monitoring pre- and post-procedure in future studies and lay down guidelines also applicable to resource-limited areas. Also, a deeper understanding of physiological and pathological mechanisms of functional outcomes post-surgery will help clinicians predict the patient's course of recovery.

Diversity trends in traumatic brain injury clinical trials in the United States

BACKGROUND

This study aims to understand the demographic representation of patients in Traumatic Brain Injury (TBI) clinical trials by evaluating the proportions of patients from various demographic categories amongst completed TBI clinical trials in the United States.

METHODS

ClinicalTrials.gov was queried for active TBI clinical trials. One hundred and eight completed trials in the United States were selected based on inclusion criteria, and information regarding intervention, setting, age, sex, race, and ethnicity was extracted. 2002-2006 TBI incidence data was obtained from the CDC. Chi-squared testing was applied to analyze the relationship between distributions of race and sex in the collected clinical trials and the national TBI data, and logistic regression was conducted to identify variables that may predict reporting of race or ethnicity.

RESULTS

About 53.7% of selected clinical trials reported racial data and 34.3% reported ethnicity data. Logistic regression identified that clinical trials in defined phases were more likely to report racial data (p = 0.047 [1.015, 9.603]).

CONCLUSION

Current TBI trials do not consistently report race or ethnicity data. Future efforts to ensure equitable representation in clinical trials may involve reform of recruitment processes and accountability measures implemented within the grant application process to ensure proper racial and ethnicity data reporting.

Daidzin improves neurobehavioral outcome in rat model of traumatic brain injury

Traumatic brain injury (TBI) is associated with the etiology of multiple neurological disorders, including neurodegeneration, leading to various cognitive deficits. Daidzin (obtained from kudzu root and soybean leaves) is known for its neuroprotective effects through multiple mechanisms. This study aimed to investigate the pharmacological effects of Daidzin on sensory, and biochemical parameters, cognitive functions, anxiety, and depressive-like behaviors in the TBI rat model. Rats were divided into four groups (Control, TBI, TBI + Ibuprofen (30 mg/kg), and TBI + Daidzin (5 mg/kg)). Rats were subjected to TBI by dropping a 200 g rod from a height of 26 cm, resulting in an impact force of 0.51 J on the exposed crania. Ibuprofen (30 mg/kg) was used as a positive control reference/standard drug and Daidzin (5 mg/kg) as the test drug. Neurological severity score (NSS) assessment was done to determine the intactness of sensory and motor responses. Brain tissue edema and acetylcholine levels were determined in the cortex and hippocampus. Cognitive functions such as hippocampus-dependent memory, novel object recognition, exploration, depressive and anxiety-like behaviors were measured. Treatment with Daidzin improved NSS, reduced hippocampal and cortical edema, and improved levels of acetylcholine in TBI-induced rats. Furthermore, Daidzin treatment improved hippocampus-dependent memory, exploration behavior, and novel object recognition while reducing depressive and anxiety-like behavior. Our study revealed that Daidzin has a therapeutic potential comparable to Ibuprofen and can offer neuroprotection and enhanced cognitive and behavioral outcomes in rats after TBI.

Post-Traumatic Epilepsy: Observations from an Urban Level 1 Trauma Center

There are approximately 2.5 million cases of traumatic brain injury (TBI) in the U.S. each year. Post-traumatic epilepsy (PTE), a sequela of TBI, has been shown to occur in approximately 15% of TBI patients. Pre-disposing risk factors for the development of PTE include severe TBI and penetrating head injury. PTE is associated with poor functional outcomes, increased negative social factors, and mental illness. We conducted a retrospective chart review with a 5-year timeframe at an urban Level 1 Trauma Center. Patients with ICD-10-CM codes associated with TBI were identified. Patients were coded as TBI with or without PTE by the presence of codes associated with PTE. Datapoints collected included risk factors for PTE and encounters with neurologists. A total of 1886 TBI patients were identified, with 178 (9.44%) classified as TBI with PTE. The most significant risk factor associated with PTE was severe brain injury, with an odds ratio (OR) of 2.955 (95% CI [2.062,4.236]; p < 0.0001). Only 19 of 178 patients (10.7%) visited a neurologist beyond 6 months after TBI. Our results suggest the presence of a significant population of patients with PTE and the need for better follow-up.

Ten Priorities for Research Addressing the Intersections of Brain Injury, Mental Health and Addictions: A Stakeholder-Driven Priority-Setting Study

OBJECTIVES

The purpose of this study was to engage key stakeholders in a health research priority-setting process to identify, prioritize and produce a community-driven list of research questions addressing intersectional issues on mental health and addictions (MHA) in acquired brain injury (ABI).

METHODS

A multiphasic health research priority-setting process was co-designed and executed with community-based stakeholders, including researchers, health professionals, clinicians, service providers, representatives from brain injury associations, policy makers and people with lived experience of ABI and MHA, including patients and their family members. Stakeholders' ideas led to the generation of research questions, which were prioritized at a 1-day workshop.

RESULTS

Fifty-nine stakeholders participated in the priority-setting activity during the workshop, which resulted in a rank-ordered list of the top 10 questions for research addressing the intersections of ABI and MHA. Questions identified touched on several pressing issues (e.g., opioid crisis, homelessness), encompassed multiple subtypes of ABI (e.g., hypoxic-ischaemic, mild traumatic), and involved different domains (e.g., identification, intervention) of health research.

CONCLUSIONS

This community-driven health research priority-setting study identified and prioritized research questions addressing the intersections of ABI and MHA. Researchers and funding agencies should use this list to inform their agendas and address stakeholders' most urgent needs, fostering meaningful improvements to clinical services.

PATIENT OR PUBLIC CONTRIBUTION

An 11-person working group comprised of people with lived experience, service providers, researchers, healthcare professionals and other key stakeholders collaboratively developed and informed the scope, design, methodology and interpretation of this study. Over 50 community-based stakeholders contributed to the research priority-setting activity. One co-author is a person with lived experience.

Utility of Early Magnetic Resonance Imaging to Enhance Outcome Prediction in Critically Ill Children with Severe Traumatic Brain Injury

BACKGROUND

Many children with severe traumatic brain injury (TBI) receive magnetic resonance imaging (MRI) during hospitalization. There are insufficient data on how different patterns of injury on early MRI inform outcomes.

METHODS

Children (3-17 years) admitted in 2010-2021 for severe TBI (Glasgow Coma Scale [GCS] score < 9) were identified using our site's trauma registry. We used multivariable modeling to determine whether the hemorrhagic diffuse axonal injury (DAI) grade and the number of regions with restricted diffusion (subcortical white matter, corpus callosum, deep gray matter, and brainstem) on MRI obtained within 7 days of injury were independently associated with time to follow commands and with Functional Independence Measure for Children (WeeFIM) scores at the time of discharge from inpatient rehabilitation. We controlled for the clinical variables age, preadmission cardiopulmonary resuscitation, pupil reactivity, motor GCS score, and fever (> 38 °C) in the first 12 h.

RESULTS

Of 260 patients, 136 (52%) underwent MRI within 7 days of injury at a median of 3 days (interquartile range [IQR] 2-4). Patients with early MRI were a median age of 11 years (IQR 7-14), 8 (6%) patients received cardiopulmonary resuscitation, 19 (14%) patients had bilateral unreactive pupils, the median motor GCS score was 1 (IQR 1-4), and 82 (60%) patients had fever. Grade 3 DAI was present in 46 (34%) patients, and restricted diffusion was noted in the corpus callosum in 75 (55%) patients, deep gray matter in 29 (21%) patients, subcortical white matter in 23 (17%) patients, and the brainstem in 20 (15%) patients. After controlling for clinical variables, an increased number of regions with restricted diffusion, but not hemorrhagic DAI grade, was independently associated with longer time to follow commands (hazard ratio 0.68, 95% confidence interval 0.53-0.89) and worse WeeFIM scores (estimate β - 4.67, 95% confidence interval - 8.33 to - 1.01).

CONCLUSIONS

Regional restricted diffusion on early MRI is independently associated with short-term outcomes in children with severe TBI. Multicenter cohort studies are needed to validate these findings and elucidate the association of early MRI features with long-term outcomes in children with severe TBI.

Neuroimaging and Clinical Findings in Healthy Middle-Aged Adults With Mild Traumatic Brain Injury in the PREVENT Dementia Study

Importance

Traumatic brain injuries (TBI) represent an important, potentially modifiable risk factor for dementia. Despite frequently observed vascular imaging changes in individuals with TBI, the relationships between TBI-associated changes in brain imaging and clinical outcomes have largely been overlooked in community cases of TBI.

Objective

To assess whether TBI are associated with and interact with midlife changes in neuroimaging and clinical features in otherwise healthy individuals.

Design, Setting, and Participants

This cross-sectional analysis used baseline data from the PREVENT Dementia program collected across 5 sites in the UK and Ireland between 2014 and 2020. Eligible participants were cognitively healthy midlife adults aged between 40 and 59 years. Data were analyzed between January 2023 and April 2024.

Exposure

Lifetime TBI history was assessed using the Brain Injury Screening Questionnaire.

Main Outcomes and Measures

Cerebral microbleeds and other markers of cerebral small vessel disease (white matter hyperintensities [WMH], lacunes, perivascular spaces) were assessed on 3T magnetic resonance imaging. Clinical measures were cognition, sleep, depression, gait, and cardiovascular disease (CVD) risk, assessed using Computerized Assessment of Information Processing (COGNITO), Pittsburgh Sleep Quality Index, Center for Epidemiologic Studies Depression Scale, clinical interviews, and the Framingham Risk Score, respectively.

Results

Of 617 participants (median [IQR] age, 52 [47-56] years; 380 female [61.6%]), 223 (36.1%) had a history of TBI. TBI was associated with higher microbleed count (β = 0.10; 95% CI, 0.01-0.18; P = .03), with a dose-response association observed with increasing number of TBI events (β = 0.05; 95% CI, 0.01-0.09; P = .03). Conversely, TBI was not associated with other measures of small vessel disease, including WMH. Furthermore, TBI moderated microbleed associations with vascular risk factors and clinical outcomes, such that associations were present only in the absence of TBI. Importantly, observations held when analyses were restricted to individuals reporting only mild TBI.

Conclusions and Relevance

In this cross-sectional study of healthy middle-aged adults, detectable changes in brain imaging and clinical features were associated with remote, even mild, TBI in the general population. The potential contribution of vascular injury to TBI-related neurodegeneration presents promising avenues to identify potential targets, with findings highlighting the need to reduce TBI through early intervention and prevention in both clinical care and policymaking.

Mitigating Traumatic Brain Injury: A Narrative Review of Supplementation and Dietary Protocols

Traumatic brain injuries (TBIs) constitute a significant public health issue and a major source of disability and death in the United States and worldwide. TBIs are strongly associated with high morbidity and mortality rates, resulting in a host of negative health outcomes and long-term complications and placing a heavy financial burden on healthcare systems. One promising avenue for the prevention and treatment of brain injuries is the design of TBI-specific supplementation and dietary protocols centred around nutraceuticals and biochemical compounds whose mechanisms of action have been shown to interfere with, and potentially alleviate, some of the neurophysiological processes triggered by TBI. For example, evidence suggests that creatine monohydrate and omega-3 fatty acids (DHA and EPA) help decrease inflammation, reduce neural damage and maintain adequate energy supply to the brain following injury. Similarly, melatonin supplementation may improve some of the sleep disturbances often experienced post-TBI. The scope of this narrative review is to summarise the available literature on the neuroprotective effects of selected nutrients in the context of TBI-related outcomes and provide an evidence-based overview of supplementation and dietary protocols that may be considered in individuals affected by-or at high risk for-concussion and more severe head traumas. Prophylactic and/or therapeutic compounds under investigation include creatine monohydrate, omega-3 fatty acids, BCAAs, riboflavin, choline, magnesium, berry anthocyanins, Boswellia serrata, enzogenol, N-Acetylcysteine and melatonin. Results from this analysis are also placed in the context of assessing and addressing important health-related and physiological parameters in the peri-impact period such as premorbid nutrient and metabolic health status, blood glucose regulation and thermoregulation following injury, caffeine consumption and sleep behaviours. As clinical evidence in this research field is rapidly emerging, a comprehensive approach including appropriate nutritional interventions has the potential to mitigate some of the physical, neurological, and emotional damage inflicted by TBIs, promote timely and effective recovery, and inform policymakers in the development of prevention strategies.

Traumatic brain injury incidence and mortality: a large population-based study

BACKGROUND

Traumatic brain injury (TBI) is a severe condition that represents a major global public health concern.

OBJECTIVES

Provide a comprehensive epidemiological outlook encompassing TBI incidence, healthcare provision and mortality.

METHODS

Population-based study in Veneto (4.9 million inhabitants), Italy, from 2012 to 2021. Hospital discharge and mortality records were used to assess incidence and mortality. Kaplan-Meier survival estimator and Cox regression models were fitted to investigate determinants of mortality.

RESULTS

Between 2012 and 2021, there were 37,487 incident TBI cases, corresponding to an age-standardized rate of 77.30/100,000 people (95% CI 76.52-78.09), higher among males, with an exponential growth after age 70. Leading causes were domestic (33.1%) and traffic accidents (17.7%), the first predominating among the elderly and children, while the latter in males 15-24 and older people. After rates stably declined between 2012 and 2019, the study captured a sharp decrease especially for traffic and occupational accidents in males, due to COVID-19 lockdown in 2020. Overall, 48.9% TBI patients were hospitalized in a specialized trauma center, with 2.6% requiring a transfer after accessing a spoke hospital. Over a 3.7 years median follow-up, 16,145 deaths were recorded, with higher mortality for those undergoing neurosurgical interventions, regardless of their access point. Risks of death increased with age, male gender, and comorbidities.

DISCUSSION

TBI incidence is characterized by distinct patterns, affecting particularly older individuals and males. Minimal hospital transfers with comparable survival irrespective of access point suggests an effective patient management within the network. The study underscores the critical need for acute-phase support and prolonged care strategies for older TBI patients.

Sleep fragmentation after traumatic brain injury impairs behavior and conveys long-lasting impacts on neuroinflammation

Traumatic brain injury (TBI) causes a prolonged inflammatory response in the central nervous system (CNS) driven by microglia. Microglial reactivity is exacerbated by stress, which often provokes sleep disturbances. We have previously shown that sleep fragmentation (SF) stress after experimental TBI increases microglial reactivity and impairs hippocampal function 30 days post-injury (DPI). The neuroimmune response is highly dynamic the first few weeks after TBI, which is also when injury induced sleep-wake deficits are detected. Therefore, we hypothesized that even a few weeks of TBI SF stress would synergize with injury induced sleep-wake deficits to promote neuroinflammation and impair outcome. Here, we investigated the effects of environmental SF in a lateral fluid percussion model of mouse TBI. Half of the mice were undisturbed, and half were exposed to 5 h of SF around the onset of the light cycle, daily, for 14 days. All mice were then undisturbed 15-30 DPI, providing a period for SF stress recovery (SF-R). Mice exposed to SF stress slept more than those in control housing 7-14 DPI and engaged in more total daily sleep bouts during the dark period. However, SF stress did not exacerbate post-TBI sleep deficits. Testing in the Morris water maze revealed sex dependent differences in spatial reference memory 9-14 DPI with males performing worse than females. Post-TBI SF stress suppressed neurogenesis-related gene expression and increased inflammatory signaling in the cortex at 14 DPI. No differences in sleep behavior were detected between groups during the SF stress recovery period 15-30 DPI. Microscopy revealed cortical and hippocampal IBA1 and CD68 percent-area increased in TBI SF-R mice 30 DPI. Additionally, neuroinflammatory gene expression was increased, and synaptogenesis-related gene expression was suppressed in TBI-SF mice 30 DPI. Finally, IPA canonical pathway analysis showed post-TBI SF impaired and delayed activation of synapse-related pathways between 14 and 30 DPI. These data show that transient SF stress after TBI impairs recovery and conveys long-lasting impacts on neuroimmune function independent of continuous sleep deficits. Together, these finding support that even limited exposure to post-TBI SF stress can have lasting impacts on cognitive recovery and regulation of the immune response to trauma.

Platelet-to-lymphocyte ratio as a prognostic predictive marker on adults with traumatic brain injury: Systematic review

Background

The platelet-to-lymphocyte ratio (PLR) has emerged as a prognostic predictive marker in various diseases, but its role in traumatic brain injury (TBI) has not been fully elucidated. This study aims to evaluate the role of PLR as a prognostic predictive marker in adults with TBI.

Methods

This systematic review was conducted according to the Preferred Reporting Items in the Systematic Review and Meta-analysis Guidelines 2020. A comprehensive search was performed using PubMed, Google Scholar, Scopus, Crossref, OpenAlex, Semantic Scholar, Library of Congress, and Jisc Library Hub Discover database to identify relevant studies published up to February 2023. Both prospective and retrospective observational studies written in English or Indonesian were included in the study. No restrictions were placed on the year and country of publication and duration of follow-up. Study quality was evaluated using the Newcastle-Ottawa Scale (NOS), and the risk of bias was estimated using the Cochrane Risk of Bias Assessment Tool for Nonrandomized Research (Ro-BANS) tool. A narrative synthesis was also conducted to summarize the findings.

Results

We retrieved 1644 references using the search strategy, and 1623 references were excluded based on screening the title and abstract. The full text was retrieved for 20 articles and subjected to the eligibility criteria, of which 16 were excluded from the study. Four papers with a total of 1.467 sample sizes were included in the review. The median of NOS for study quality was 8-9, with the risk of selection bias using the Ro-BANS tool being low in all studies except for the blinding outcome assessments, which are all unclear. The study finding suggests that the PLR has the potential as an independent prognostic predictive marker in adult patients with TBI. In three studies, a high level of admission PLR may independently predict an increasing mortality risk in 30 days and adverse outcomes measured by the Glasgow outcome scale in 6 months following TBI. However, one study shows that PLR may have limited value as a predictor of mortality or favorable neurological outcomes compared to other hematological parameters. Further studies were needed to establish the clinical utility of PLR and fill the present gaps.

Conclusion

This systematic review provides evidence supporting the utilization of PLR as a prognostic predictive marker in adult patients with TBI. The PLR can mainly be utilized, especially in rural practice, as PLR is a simple, low-cost, and routinely performed hematological examination.

Effectiveness of telehealth interventions among traumatic brain injury survivors: A systematic review and meta-analysis

INTRODUCTION

Traumatic brain injury (TBI) represents a major cause of death and disability worldwide. Brain damage is associated with physical and psychological difficulties among TBI survivors. Diverse face-to-face and telehealth programs exist to help survivors cope with these burdens. However, the effectiveness of telehealth interventions among TBI survivors remains inconclusive.

METHODS

A systematic review and meta-analysis of randomized control trials were conducted. Relevant full-text articles were retrieved from seven databases, from database inception to January 2022, including Academic Search Complete, CINAHL, EMBASE, Cochrane, MEDLINE, PubMed, and Web of Science. Bias was assessed with the revised Cochrane risk-of-bias tool for randomized trials. A meta-analysis was performed using a random-effects model to calculate the pooled effect size of telehealth interventions for TBI survivors. STATA 16.0 was used for statistical analysis.

RESULTS

In total, 17 studies (N = 3158) applying telehealth interventions among TBI survivors were included in the analysis. Telehealth interventions decreased neurobehavioural symptom (standardized mean difference: -0.13; 95% confidence interval [CI]: -0.36 to 0.10), reduce depression (standardized mean difference: -0.32; 95% CI: -0.79 to 0.14), and increase symptom management self-efficacy (standardized mean difference: 0.22; 95% CI: 0.02-0.42).

DISCUSSION

Telehealth interventions are promising avenues for healthcare delivery due to advances in technology and information. Telehealth programs may represent windows of opportunity, combining traditional treatment with rehabilitation to increase symptom management self-efficacy among TBI patients during recovery. Future telehealth programs can focus on developing the contents of telehealth modules based on evidence from this study.

Effect of PCC on outcomes of severe traumatic brain injury patients on preinjury anticoagulation

INTRODUCTION

This study aims to evaluate effect of 4-factor PCC on outcomes of severe TBI patients on preinjury anticoagulants undergoing craniotomy/craniectomy.

METHODS

In this analysis of 2018-2020 ACS-TQIP, patients with isolated blunt severe TBI (Head-AIS≥3, nonhead-AIS<2) using preinjury anticoagulants who underwent craniotomy/craniectomy were identified and stratified into PCC and No-PCC groups. Outcomes were time to surgery and mortality. Multivariable binary logistic and linear regression analyses were performed.

RESULTS

1598 patients were identified (PCC-107[7 %], No-PCC-1491[93 %]). Mean age was 74(11) years, 65 % were male, median head AIS was 4. Median time to PCC administration was 109 ​min. On univariable analysis, PCC group had shorter time to surgery (PCC-341, No-PCC-620 ​min, p ​= ​0.002), but higher mortality (PCC35 %, No-PCC21 %,p ​= ​0.001). On regression analysis, PCC was independently associated with shorter time to surgery (β ​= ​-1934,95 %CI ​= ​-3339to-26), but not mortality (aOR ​= ​0.70,95 %CI ​= ​0.14-3.62).

CONCLUSION

PCC may be a safe adjunct for urgent reversal of coagulopathy in TBI patients using preinjury anticoagulants.

The Cumulative Incidence of Post-Traumatic Epilepsy After Mild Traumatic Brain Injury: A Systematic Review and Individual Participant Data Meta-Analysis Protocol

A precise understanding of the latency to post-traumatic epilepsy (PTE) following a traumatic brain injury (TBI) is necessary for optimal patient care. This precision is currently lacking despite a surprising number of available data sources that could address this pressing need. Following guidance from the Cochrane Collaboration and Joanna Briggs Institute, we conduct a systematic review to address the research questions: What is the cumulative incidence of PTE following mild TBI (mTBI; concussion), and what is the distribution of the latency to onset? We designed a comprehensive search of medical databases and gray literature sources. Citations will be screened on both abstract and full-text levels, independently and in duplicate. Studies will be evaluated for risk of bias independently and in duplicate using published instruments specific to incidence/prevalence studies. Data will be abstracted independently and in duplicate using piloted extraction forms. Disagreements will be resolved by consensus or third-party adjudication. Evidence synthesis will involve pairwise and individual participant data meta-analysis with heterogeneity explored via a set of predetermined subgroups. The robustness of the findings will be subjected to sensitivity analyses based on the risk of bias, outlier studies, and mTBI definitional criteria. The overall certainty in the estimates will be reported using GRADE (Grading of Recommendations, Assessment, Development, and Evaluations). This protocol presents an innovative and impactful approach to build on the growing body of knowledge surrounding post-mTBI PTE. Through a precise understanding of the latency period, this study can contribute to early detection, tailored interventions, and improved outcomes, leading to a substantial impact on patient care and quality of life.

Traumatic Brain Injury: A Comprehensive Review of Biomechanics and Molecular Pathophysiology

Traumatic brain injury (TBI) is a critical public health concern with profound consequences for affected individuals. This comprehensive literature review delves into TBI intricacies, encompassing primary injury biomechanics and the molecular pathophysiology of the secondary injury cascade. Primary TBI involves a complex interplay of forces, including impact loading, blast overpressure, and impulsive loading, leading to diverse injury patterns. These forces can be categorized into inertial (e.g., rotational acceleration causing focal and diffuse injuries) and contact forces (primarily causing focal injuries like skull fractures). Understanding their interactions is crucial for effective injury management. The secondary injury cascade in TBI comprises multifaceted molecular and cellular responses, including altered ion concentrations, dysfunctional neurotransmitter networks, oxidative stress, and cellular energy disturbances. These disruptions impair synaptic function, neurotransmission, and neuroplasticity, resulting in cognitive and behavioral deficits. Moreover, neuroinflammatory responses play a pivotal role in exacerbating damage. As we endeavor to bridge the knowledge gap between biomechanics and molecular pathophysiology, further research is imperative to unravel the nuanced interplay between mechanical forces and their consequences at the molecular and cellular levels, ultimately guiding the development of targeted therapeutic strategies to mitigate the debilitating effects of TBI. In this study, we aim to provide a concise review of the bridge between biomechanical processes causing primary injury and the ensuing molecular pathophysiology of secondary injury, while detailing the subsequent clinical course for this patient population. This knowledge is crucial for advancing our understanding of TBI and developing effective interventions to improve outcomes for those affected.

Establishing a 3-Tesla Magnetic Resonance Imaging Method for Assessing Diffuse Axonal Brain Injury in Rats

Traumatic brain injury (TBI) significantly contributes to death and disability worldwide. However, treatment options remain limited. Here, we focus on a specific pathology of TBI, diffuse axonal brain injury (DABI), which describes the process of the tearing of nerve fibers in the brain after blunt injury. Most protocols to study DABI do not incorporate a specific model for that type of pathology, limiting their ability to identify mechanisms and comorbidities of DABI. In this study, we developed a magnetic resonance imaging (MRI) protocol for DABI in a rat model using a 3-T clinical scanner. We compared the neuroimaging outcomes with histologic and neurologic assessments. In a sample size of 10 rats in the sham group and 10 rats in the DABI group, we established neurological severity scores before the intervention and at 48 h following DABI induction. After the neurological evaluation after DABI, all rats underwent MRI scans and were subsequently euthanized for histological evaluation. As expected, the neurological assessment showed a high sensitivity for DABI lesions indicated using the β-APP marker. Surprisingly, however, we found that the MRI method had greater sensitivity in assessing DABI lesions compared to histological methods. Out of the five MRI parameters with pathological changes in the DABI model, we found significant changes compared to sham rats in three parameters, and, as shown using comparative tests with other models, MRI was the most sensitive parameter, being even more sensitive than histology. We anticipate that this DABI protocol will have a significant impact on future TBI and DABI studies, advancing research on treatments specifically targeted towards improving patient quality of life and long-term outcomes.

Cytokine Release by Microglia Exposed to Neurologic Injury Is Amplified by Lipopolysaccharide

INTRODUCTION

Traumatic brain injury (TBI) is a leading cause of death and morbidity in the trauma population. Microglia drive the secondary neuroinflammatory response after TBI. We sought to determine if the microglial response to neurologic injury was exacerbated by a second stimulus after exposure to neurologic injury.

METHODS

Sprague-Dawley rats (age 2-3 wk) were divided into injured and noninjured groups. Injured rats underwent a controlled cortical impact injury; noninjured rats remained naïve to any injury and served as the control group. Primary rat microglia were isolated and applied to in vitro cultures. After incubation for 24 h, the microglia were stimulated with lipopolysaccharide (LPS) or norepinephrine. Twenty-four hours after stimulation, cell culture supernatant was collected. Tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) production were measured by standard enzyme-linked immunosorbent assays. GraphPad Prism was used for statistical analysis.

RESULTS

When compared to noninjured microglia, LPS induced a significantly greater production of TNF-α in microglia isolated from the injured ipsilateral (versus noninjured = 938.8 ± 155.1, P < 0.0001) and injured contralateral hemispheres (versus noninjured = 426.6 ± 155.1, P < 0.0001). When compared to microglia from noninjured cerebral tissue, IL-6 production was significantly greater after LPS stimulation in the injured ipsilateral hemisphere (mean difference versus noninjured = 9540 ± 3016, P = 0.0101) and the contralateral hemisphere (16,700 ± 3016, P < 0.0001). Norepinephrine did not have a significant effect on IL-6 or TNF-α production.

CONCLUSIONS

LPS stimulation may amplify the release of proinflammatory cytokines from postinjury microglia. These data suggest that post-TBI complications, like sepsis, may propagate neuroinflammation by augmenting the proinflammatory response of microglia.

Mild Traumatic Brain Injury-Induced Augmented Postsurgical Pain Is Driven by Central Serotonergic Pain-Facilitatory Signaling

BACKGROUND

Individuals recovering from mild traumatic brain injury (mTBI) have increased rates of acute and chronic pain. However, the mechanism through which mTBI triggers heightened pain responses and the link between mTBI and postsurgical pain remain elusive. Recent data suggest that dysregulated serotonergic pain-modulating circuits could be involved. We hypothesized that mTBI triggers dysfunction in descending serotonergic pain modulation, which exacerbates acute pain and delays pain-related recovery after surgery.

METHODS

Using mouse models of mTBI and hindpaw incision for postsurgical pain in C57BL/6J mice, mechanical withdrawal thresholds were assessed throughout the postsurgical period. To determine whether mTBI leads to persistent alteration of endogenous opioid tone, mu-opioid receptors (MORs) were blocked with naloxone. Finally, the role of descending serotonergic signaling on postsurgical allodynia in animals with mTBI was examined using ondansetron (5-HT 3 receptor antagonist) or a serotonin-specific neurotoxin, 5,7-dihydroxytryptamine (5,7-DHT), to ablate descending serotonergic fibers. The treatment effects on withdrawal thresholds were normalized to baseline (percentage of maximum possible effect, MPE%), and analyzed using paired t -test or 2-way repeated-measures ANOVA with post hoc multiple comparisons.

RESULTS

Post-mTBI mice demonstrated transient allodynia in hindpaws contralateral to mTBI, while no nociceptive changes were observed in sham-mTBI animals (mean difference, MD, MPE%, post-mTBI day 3: -60.9; 95% CI, -88.7 to -35.0; P < .001). After hindpaw incision, animals without mTBI exhibited transient allodynia, while mice with prior mTBI demonstrated prolonged postsurgical allodynia (MD-MPE% postsurgical day 14: -65.0; 95% CI, -125.4 to -4.5; P = .04). Blockade of MORs using naloxone transiently reinstated allodynia in mTBI animals but not in sham-mTBI mice (MD-MPE% post-naloxone: -69.9; 95% CI, -94.8 to -45.1; P < .001). Intrathecal administration of ondansetron reversed the allodynia observed post-mTBI and postincision in mTBI mice (compared to vehicle-treated mTBI mice, MD-MPE% post-mTBI day 3: 82.7; 95% CI, 58.5-106.9; P < .001; postsurgical day 17: 62.5; 95% CI, 38.3-86.7; P < .001). Both the acute allodynia after TBI and the period of prolonged allodynia after incision in mTBI mice were blocked by pretreatment with 5,7-DHT (compared to sham-mTBI mice, MD-MPE% post-mTBI day 3: 0.5; 95% CI, -18.5 to 19.5; P = .99; postsurgical day 14: -14.6; 95% CI, -16.7 to 45.9; P = .48). Similar behavioral patterns were observed in hindpaw ipsilateral to mTBI.

CONCLUSIONS

Collectively, our results show that descending serotoninergic pain-facilitating signaling is responsible for nociceptive sensitization after mTBI and that central endogenous opioid tone opposes serotonin's effects. Understanding brain injury-related changes in endogenous pain modulation may lead to improved pain control for those with TBI undergoing surgery.

Prevalence of fatigue and cognitive impairment after traumatic brain injury

BACKGROUND

Following traumatic brain injury (TBI) some patients develop lingering comorbid symptoms of fatigue and cognitive impairment. The mild cognitive impairment self-reported by patients is often not detected with neurocognitive tests making it difficult to determine how common and severe these symptoms are in individuals with a history of TBI. This study was conducted to determine the relative prevalence of fatigue and cognitive impairment in individuals with a history of TBI.

METHODS

The Fatigue and Altered Cognition Scale (FACs) digital questionnaire was used to assess self-reported fatigue and cognitive impairment. Adults aged 18-70 were digitally recruited for the online anonymous study. Eligible participants provided online consent, demographic data, information about lifetime TBI history, and completed the 20 item FACs questionnaire.

RESULTS

A total of 519 qualifying participants completed the online digital study which included 204 participants with a history of TBI of varied cause and severity and 315 with no history of TBI. FACs Total Score was significantly higher in the TBI group (57.7 ± 22.2) compared to non-TBI (39.5 ± 23.9; p<0.0001) indicating more fatigue and cognitive impairment. When stratified by TBI severity, FACs score was significantly higher for all severity including mild (53.9 ± 21.9, p<0.0001), moderate (54.8 ± 24.4, p<0.0001), and severe (59.7 ± 20.9, p<0.0001) TBI. Correlation analysis indicated that more severe TBI was associated with greater symptom severity (p<0.0001, r = 0.3165). Ancillary analysis also suggested that FACs scores may be elevated in participants with prior COVID-19 infection but no history of TBI.

CONCLUSIONS

Adults with a history of even mild TBI report significantly greater fatigue and cognitive impairment than those with no history of TBI, and symptoms are more profound with greater TBI severity.

Context is key: glucocorticoid receptor and corticosteroid therapeutics in outcomes after traumatic brain injury

Traumatic brain injury (TBI) is a global health burden, and survivors suffer functional and psychiatric consequences that can persist long after injury. TBI induces a physiological stress response by activating the hypothalamic-pituitary-adrenal (HPA) axis, but the effects of injury on the stress response become more complex in the long term. Clinical and experimental evidence suggests long lasting dysfunction of the stress response after TBI. Additionally, pre- and post-injury stress both have negative impacts on outcome following TBI. This bidirectional relationship between stress and injury impedes recovery and exacerbates TBI-induced psychiatric and cognitive dysfunction. Previous clinical and experimental studies have explored the use of synthetic glucocorticoids as a therapeutic for stress-related TBI outcomes, but these have yielded mixed results. Furthermore, long-term steroid treatment is associated with multiple negative side effects. There is a pressing need for alternative approaches that improve stress functionality after TBI. Glucocorticoid receptor (GR) has been identified as a fundamental link between stress and immune responses, and preclinical evidence suggests GR plays an important role in microglia-mediated outcomes after TBI and other neuroinflammatory conditions. In this review, we will summarize GR-mediated stress dysfunction after TBI, highlighting the role of microglia. We will discuss recent studies which target microglial GR in the context of stress and injury, and we suggest that cell-specific GR interventions may be a promising strategy for long-term TBI pathophysiology.

The Effect of Dexamethasone on Neuroinflammation and Cerebral Edema in Rats With Traumatic Brain Injury Combined With Seawater Drowning

OBJECTIVE

To investigate the effect and mechanism of dexamethasone (DX) on axonal injury after traumatic brain injury (TBI) combined with seawater drowning (SWD) in rats.

METHODS

To gain an in-depth understanding of TBI + SWD in rats, we established the compound injury model of rats by the Marmarou method and intratracheal pumping of seawater to simulate the pathological conditions. Rats in the DX group received intraperitoneal injections of DX (1 mg/kg) immediately after injury, and rats in the sham group and TBI + SWD group received intraperitoneal injections of the same amount of normal saline.

RESULTS

Hematoxylin-eosin (HE) showed that DX improved matrix looseness, cell swelling, and nuclear condensation 168 hours after injury. Immunohistochemistry (IHC) staining showed that the protein expression of AQP4 was decreased in the DX group compared with the TBI + SWD group from 12 hours to 168 hours after injury. DX decreased the modified neurological severity score (mNSS) significantly at 24 hours and 168 hours after injury (P < 0.05). At 72 h and 168 h after injury, DX significantly lowered the expressions of IL-8 and TNF-α (P < 0.05).

CONCLUSION

DX may play a neuroprotective role by reducing cerebral edema and inflammatory response after TBI + SWD injury in rats.

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.

Effect of low fibrinogen level on in-hospital mortality and 6-month functional outcome of TBI patients, a single center experience

In patients affected by traumatic brain injury (TBI), hypofibrinogenemia within the initial hours of trauma can be expected due to vascular and inflammatory changes. In this study, we aimed to evaluate the effect of hypofibrinogenemia on the in-hospital mortality and 6-month functional outcomes of TBI patients, admitted to Rajaee Hospital, a referral trauma center in Shiraz, Iran. This study included all TBI patients admitted to our center who had no prior history of coagulopathy or any systemic disease, were alive on arrival, and had not received any blood product before admission. On admission, hospitalization, imaging, and 6-month follow-up information of included patients were extracted from the TBI registry database. The baseline characteristics of patients with fibrinogen levels of less than 150 mg/dL were compared with the cases with higher levels. To assess the effect of low fibrinogen levels on in-hospital mortality, a uni- and multivariate was conducted between those who died in hospital and survivors. Based on the 6-month GOSE score of patients, those with GOSE < 4 (unfavorable outcome) were compared with those with a favorable outcome. A total of 3049 patients (84.3% male, 15.7% female), with a mean age of 39.25 ± 18.87, met the eligibility criteria of this study. 494 patients had fibrinogen levels < 150 mg/dl, who were mostly younger and had lower average GCS scores in comparison to cases with higher fibrinogen levels. By comparison of the patients who died during hospitalization and survivors, it was shown that fibrinogen < 150 mg/dl is among the prognostic factors for in-hospital mortality (OR:1.75, CI: 1.32:2.34, P-value < 0.001), while the comparison between patients with the favorable and unfavorable functional outcome at 6-month follow-up, was not in favor of prognostic effect of low fibrinogen level (OR: 0.80, CI: 0.58: 1.11, P-value: 0.19). Hypofibrinogenemia is associated with in-hospital mortality of TBI patients, along with known factors such as higher age and lower initial GCS score. However, it is not among the prognostic factors of midterm functional outcome.

Reactive gliosis in traumatic brain injury: a comprehensive review

Traumatic brain injury (TBI) is one of the most common pathological conditions impacting the central nervous system (CNS). A neurological deficit associated with TBI results from a complex of pathogenetic mechanisms including glutamate excitotoxicity, inflammation, demyelination, programmed cell death, or the development of edema. The critical components contributing to CNS response, damage control, and regeneration after TBI are glial cells-in reaction to tissue damage, their activation, hypertrophy, and proliferation occur, followed by the formation of a glial scar. The glial scar creates a barrier in damaged tissue and helps protect the CNS in the acute phase post-injury. However, this process prevents complete tissue recovery in the late/chronic phase by producing permanent scarring, which significantly impacts brain function. Various glial cell types participate in the scar formation, but this process is mostly attributed to reactive astrocytes and microglia, which play important roles in several brain pathologies. Novel technologies including whole-genome transcriptomic and epigenomic analyses, and unbiased proteomics, show that both astrocytes and microglia represent groups of heterogenic cell subpopulations with different genomic and functional characteristics, that are responsible for their role in neurodegeneration, neuroprotection and regeneration. Depending on the representation of distinct glia subpopulations, the tissue damage as well as the regenerative processes or delayed neurodegeneration after TBI may thus differ in nearby or remote areas or in different brain structures. This review summarizes TBI as a complex process, where the resultant effect is severity-, region- and time-dependent and determined by the model of the CNS injury and the distance of the explored area from the lesion site. Here, we also discuss findings concerning intercellular signaling, long-term impacts of TBI and the possibilities of novel therapeutical approaches. We believe that a comprehensive study with an emphasis on glial cells, involved in tissue post-injury processes, may be helpful for further research of TBI and be the decisive factor when choosing a TBI model.

Sex-Biased Expression and Response of microRNAs in Neurological Diseases and Neurotrauma

Neurological diseases and neurotrauma manifest significant sex differences in prevalence, progression, outcome, and therapeutic responses. Genetic predisposition, sex hormones, inflammation, and environmental exposures are among many physiological and pathological factors that impact the sex disparity in neurological diseases. MicroRNAs (miRNAs) are a powerful class of gene expression regulator that are extensively involved in mediating biological pathways. Emerging evidence demonstrates that miRNAs play a crucial role in the sex dimorphism observed in various human diseases, including neurological diseases. Understanding the sex differences in miRNA expression and response is believed to have important implications for assessing the risk of neurological disease, defining therapeutic intervention strategies, and advancing both basic research and clinical investigations. However, there is limited research exploring the extent to which miRNAs contribute to the sex disparities observed in various neurological diseases. Here, we review the current state of knowledge related to the sexual dimorphism in miRNAs in neurological diseases and neurotrauma research. We also discuss how sex chromosomes may contribute to the miRNA sexual dimorphism phenomenon. We attempt to emphasize the significance of sexual dimorphism in miRNA biology in human diseases and to advocate a gender/sex-balanced science.

The effect of processing speed on verbal and visual memory of adults with a chronic acquired brain injury

OBJECTIVE

Memory problems are among the most frequently reported cognitive complaints by individuals with an acquired brain injury (ABI). Processing speed and working memory deficits are often the result of ABI. These cognitive deficits significantly impact the acquisition and retention of information necessary for memory formation. This study investigated the influence of processing speed and working memory on immediate and delayed recall for verbal and visual memory, as well as overall memory recall in adults living with a chronic ABI.

METHODS

Sixty-three participants living with a chronic ABI, who were at least one-year post-injury, were cognitively assessed with the CNS-Vital Signs (CNS-VS) computerized cognitive battery and Wechsler Test of Adult Reading.

RESULTS

The CNS-VS Processing Speed significantly predicted delayed recall for verbal memory and overall memory performance. The CNS-VS Working Memory was not a significant predictor of memory recall.

CONCLUSIONS

Processing speed deficits negatively impact memory in individuals with a chronic ABI. These findings suggest the memory recall of adults with a chronic ABI is associated with poor processing speed and poor acquisition of information. Therefore, cognitive rehabilitation that improves processing speed should be the focus for individuals with ABI to improve memory performance as well as impaired processing speed.

Amantadine for functional improvement in patients with traumatic brain injury: A systematic review with meta-analysis and trial sequential analysis

Introduction

TBIs contribute in over one-third of injury-related deaths with mortality rates as high as 50% in trauma centers serving the most severe TBI. The effect of TBI on mortality is about 10% across all ages. Amantadine hydrochloride is one of the most commonly prescribed medications for patients undergoing inpatient neurorehabilitation who have disorders of consciousness.6 It is a dopamine (DA) receptor agonist and a N-Methyl-D-aspartate (NMDA) receptor antagonist via dopamine release and dopamine reuptake inhibition. The current study will synthesize the current available evidence and show the effect of Amantadine in functional improvement after TBI.

Research question

Does Amantadine have an effect on functional improvement of TBI patients?

Material and methods

This systematic review included all randomized placebo-controlled trials that compare the use of Amantadine versus placebo for functional improvement of patients after TBI. Outcome measures included DRS, GCS and/or GOS scores.

Results

Three studies with a total of 281 patients were included in the quantitative analyses. GRADE assessments show that there was a high certainty of evidence for functional improvement in terms of DRS scores.

Discussion and conclusion

Evidence of this review show that the use of Amantadine may have a beneficial effect on functional outcome in moderate to severe traumatic brain injuries among adult patients. Given the still-limited body of knowledge, more relevant studies must be made exploring the impact of Amantadine therapies on promoting functional recovery within the brain injury rehabilitation care continuum, with the goals of achieving larger sample sizes and establishing the early- or later-treatment beneficial effects.

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.

Evaluating GCS and FOUR Score in Predicting Mortality of Traumatic Brain Injury Patients (TBI): A Prospective Study in a Tertiary Hospital of South Malabar

Objective

This study evaluated the full outline of Unresponsiveness (FOUR) score and Glasgow Coma Scale (GCS) to predict traumatic brain injury (TBI) outcomes.

Methods

Among 107 patients, FOUR and GCS grading systems analyzed emergency department patients within 24 hours. FOUR and GCS were assessed simultaneously. Patients were followed for 15 days/discharge/death to evaluate the results. Modified Rankin scores measured in-hospital mortality, morbidity, and stay.

Results

65.42% of patients were 25-65. 10% were under 25, and 25% were over 65. Patients were 81% male. Road traffic accidents (RTAs) (90%), falls (7.48%), and assaults (1.47%) caused TBI. 19.62% died. 85.7% of 21 non-survivors had GCS <5 and FOUR <4. GCS mortality sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 85.71%, 93.02%, 75, and 96.4 (P < 0.0001). FOUR score mortality sensitivity, specificity, PPV, and NPV were 85.71%, 96.51%, 85.7, and 96.5 (P < 0.0001). GCS and FOUR AUCs matched (P = 0.52). The unadjusted model reduced in-hospital mortality by 14% for every one point increase in GCS. Every 1-point FOUR score increase reduced in-hospital mortality by 40% in the unadjusted model. GCS and FOUR scored 0.9 Spearman.

Conclusion

The FOUR score was comparable in the prediction of mortality in these patients.

Impaired cortical neuronal homeostasis and cognition after diffuse traumatic brain injury are dependent on microglia and type I interferon responses

Neuropsychiatric complications including depression and cognitive decline develop in the years after traumatic brain injury (TBI), negatively affecting quality of life. Microglial and type 1 interferon (IFN-I) responses are associated with the transition from acute to chronic neuroinflammation after diffuse TBI in mice. Thus, the purpose of this study was to determine if impaired neuronal homeostasis and increased IFN-I responses intersected after TBI to cause cognitive impairment. Here, the RNA profile of neurons and microglia after TBI (single nucleus RNA-sequencing) with or without microglia depletion (CSF1R antagonist) was assessed 7 dpi. There was a TBI-dependent suppression of cortical neuronal homeostasis with reductions in CREB signaling, synaptogenesis, and synaptic migration and increases in RhoGDI and PTEN signaling (Ingenuity Pathway Analysis). Microglial depletion reversed 50% of TBI-induced gene changes in cortical neurons depending on subtype. Moreover, the microglial RNA signature 7 dpi was associated with increased stimulator of interferon genes (STING) activation and IFN-I responses. Therefore, we sought to reduce IFN-I signaling after TBI using STING knockout mice and a STING antagonist, chloroquine (CQ). TBI-associated cognitive deficits in novel object location and recognition (NOL/NOR) tasks at 7 and 30 dpi were STING dependent. In addition, TBI-induced STING expression, microglial morphological restructuring, inflammatory (Tnf, Cd68, Ccl2) and IFN-related (Irf3, Irf7, Ifi27) gene expression in the cortex were attenuated in STINGKO mice. CQ also reversed TBI-induced cognitive deficits and reduced TBI-induced inflammatory (Tnf, Cd68, Ccl2) and IFN (Irf7, Sting) cortical gene expression. Collectively, reducing IFN-I signaling after TBI with STING-dependent interventions attenuated the prolonged microglial activation and cognitive impairment.