Traumatic Brain Injury Events Research Articles

B - 35 Recall of the Injury Event in Moderate–Severe Traumatic Brain Injury

Abstract Objective Autobiographical recall can be impoverished in Traumatic Brain Injury (TBI). We explored whether the recall of the TBI event was unique to this trend since the event is both self-defining and traumatic. Methods We recruited 30 non-injured comparison participants (NC) and 30 participants in the chronic phase of a moderate–severe TBI from the Brain Injury Patient Registry at Vanderbilt University Medical Center. Participants in the TBI group recalled their TBI event and a self-selected event from 0–5 years before the TBI. The NC group recalled a self-selected event that matched the pre-injury’s temporal distance. We used the Autobiographical Interview scoring system to test whether events differed in the amount and type of details. Results Compared to the pre-injury event, the injury event had a higher number of episodic-like, p = 0.002, and external details (e.g., repetition and meta-comments), p = 0.011. The injury and pre-injury events had a similar proportion of episodic-like details (relative to all details), p = 0.295, indicating events were similarly supplemented with extraneous/inferential information. Further, the pre-injury event of the TBI group had a smaller number of episodic-like details, p < 0.001, and a lower proportion of episodic-like details, p = 0.002, than the events from the NC group. Conclusion Whereas the recall of injury events may be unique due to their higher number of episodic-like details, they were also similar to general autobiographical memory recall in the preponderance of supplementary details. A confluence of factors, like personal relevance, compromised encoding due to loss of consciousness at the time of injury, and general difficulties in retrieval, may explain the findings.

Calcium and Non-Penetrating Traumatic Brain Injury: A Proposal for the Implementation of an Early Therapeutic Treatment for Initial Head Insults.

Finding an effective treatment for traumatic brain injury is challenging for multiple reasons. There are innumerable different causes and resulting levels of damage for both penetrating and non-penetrating traumatic brain injury each of which shows diverse pathophysiological progressions. More concerning is that disease progression can take decades before neurological symptoms become obvious. Currently, the primary treatment for non-penetrating mild traumatic brain injury, also called concussion, is bed rest despite the fact the majority of emergency room visits for traumatic brain injury are due to this mild form. Furthermore, one-third of mild traumatic brain injury cases progress to long-term serious symptoms. This argues for the earliest therapeutic intervention for all mild traumatic brain injury cases which is the focus of this review. Calcium levels are greatly increased in damaged brain regions as a result of the initial impact due to tissue damage as well as disrupted ion channels. The dysregulated calcium level feedback is a diversity of ways to further augment calcium neurotoxicity. This suggests that targeting calcium levels and function would be a strong therapeutic approach. An effective calcium-based traumatic brain injury therapy could best be developed through therapeutic programs organized in professional team sports where mild traumatic brain injury events are common, large numbers of subjects are involved and professional personnel are available to oversee treatment and documentation. This review concludes with a proposal with that focus.

Random forest-based prediction of intracranial hypertension in patients with traumatic brain injury

BackgroundTreatment and prevention of intracranial hypertension (IH) to minimize secondary brain injury are central to the neurocritical care management of traumatic brain injury (TBI). Predicting the onset of IH in advance allows for a more aggressive prophylactic treatment. This study aimed to develop random forest (RF) models for predicting IH events in TBI patients.MethodsWe analyzed prospectively collected data from patients admitted to the intensive care unit with invasive intracranial pressure (ICP) monitoring. Patients with persistent ICP > 22 mmHg in the early postoperative period (first 6 h) were excluded to focus on IH events that had not yet occurred. ICP-related data from the initial 6 h were used to extract linear (ICP, cerebral perfusion pressure, pressure reactivity index, and cerebrospinal fluid compensatory reserve index) and nonlinear features (complexity of ICP and cerebral perfusion pressure). IH was defined as ICP > 22 mmHg for > 5 min, and severe IH (SIH) as ICP > 22 mmHg for > 1 h during the subsequent ICP monitoring period. RF models were then developed using baseline characteristics (age, sex, and initial Glasgow Coma Scale score) along with linear and nonlinear features. Fivefold cross-validation was performed to avoid overfitting.ResultsThe study included 69 patients. Forty-three patients (62.3%) experienced an IH event, of whom 30 (43%) progressed to SIH. The median time to IH events was 9.83 h, and to SIH events, it was 11.22 h. The RF model showed acceptable performance in predicting IH with an area under the curve (AUC) of 0.76 and excellent performance in predicting SIH (AUC = 0.84). Cross-validation analysis confirmed the stability of the results.ConclusionsThe presented RF model can forecast subsequent IH events, particularly severe ones, in TBI patients using ICP data from the early postoperative period. It provides researchers and clinicians with a potentially predictive pathway and framework that could help triage patients requiring more intensive neurological treatment at an early stage.

Single episode of moderate to severe traumatic brain injury leads to chronic neurological deficits and Alzheimer's-like pathological dementia.

Traumatic brain injury (TBI) is one of the foremost causes of disability and mortality globally. While the scientific and medical emphasis is to save lives and avoid disability during acute period of injury, a severe health problem can manifest years after injury. For instance, TBI increases the risk of cognitive impairment in the elderly. Remote TBI history was reported to be a cause of the accelerated clinical trajectory of Alzheimer's disease-related dementia (ADRD) resulting in earlier onset of cognitive impairment and increased AD-associated pathological markers like greater amyloid deposition and cortical thinning. It is not well understood whether a single TBI event may increase the risk of dementia. Moreover, the cellular signaling pathways remain elusive for the chronic effects of TBI on cognition. We have hypothesized that a single TBI induces sustained neuroinflammation and disrupts cellular communication in a way that results later in ADRD pathology. To test this, we induced TBI in young adult CD1 mice and assessed the behavioral outcomes after 11months followed by pathological, histological, transcriptomic, and MRI assessment. On MRI scans, these mice showed significant loss of tissue, reduced CBF, and higher white matter injury compared to sham mice. We found these brains showed progressive atrophy, markers of ADRD, sustained astrogliosis, loss of neuronal plasticity, and growth factors even after 1-year post-TBI. Because of progressive neurodegeneration, these mice had motor deficits, showed cognitive impairments, and wandered randomly in open field. We, therefore, conclude that progressive pathology after adulthood TBI leads to neurodegenerative conditions such as ADRD and impairs neuronal functions.

265 Inpatient Outcomes in Pediatric Patients With Non-accidental Versus Accidental Head Trauma: National Trauma Data Bank Analysis

INTRODUCTION: Non-accidental trauma (NAT) is a leading cause of pediatric traumatic brain injury (TBI). Recent studies suggest NAT results in worse outcomes than accidental TBI, independent of severity of the injury and interventions. METHODS: Patients under 18 years old diagnosed with head trauma with or without NAT during 2019-2021 were identified in the NTDB. The predictor variables were demographics; previously validated prognostic factors , including motor score, verbal score, pupillary score, pupillary reactivity, image findings; neurosurgical interventions including EVD, ICPM, PbO2 monitoring; length of stay, and number of ventilated days. Data evaluation and univariate analysis were performed using summary statistics, t-tests, chi-square tests, and non-parametric tests. Mortality, length of ICU stay and complication rates were modeled using a multivariate logistic regression model. Outcomes were controlled for age, race, sex, and teaching vs nonteaching hospital. RESULTS: A total of 90,607 pediatric TBI events were identified in the database, 1721 (1.90%) cases with NAT. NAT was observed most often in 0-2 year-olds (64.78%), followed by 2-5 year-olds (22.66%), 6-10 and 15-18 year-olds (0.09% each), then 11-14 year-olds (0.07%). Patients with NAT had longer ICU stays (6.18 vs 4.93 days, p < 0.0001) and ventilator days, despite similar injury severity scores (p < 0.0001). In-hospital mortality was 30% more likely if NAT was the MOI (LR 1.3046, p < 0.001). CONCLUSIONS: Pediatric TBI patients with NAT have worse inpatient outcomes than similar patients with accidental injuries. Accurate diagnosis and better prognostication scales specific to patients with non-accidental trauma may lead to improved management and resource allocations for these sicker patients.

A Novel Experimental Approach for the Measurement of Vibration-Induced Changes in the Rheological Properties of Ex Vivo Ovine Brain Tissue.

Increased incidence of traumatic brain injury (TBI) imposes a growing need to understand the pathology of brain trauma. A correlation between the incidence of multiple brain traumas and rates of behavioural and cognitive deficiencies has been identified amongst people that experienced multiple TBI events. Mechanically, repetitive TBIs may affect brain tissue in a similar way to cyclic loading. Hence, the potential susceptibility of brain tissue to mechanical fatigue is of interest. Although temporal changes in ovine brain tissue viscoelasticity and biological fatigue of other tissues such as tendons and arteries have been investigated, no methodology currently exists to cyclically load ex vivo brain tissue. A novel rheology-based approach found a consistent, initial stiffening response of the brain tissue before a notable softening when subjected to a subsequential cyclic rotational shear. History dependence of the mechanical properties of brain tissue indicates susceptibility to mechanical fatigue. Results from this investigation increase understanding of the fatigue properties of brain tissue and could be used to strengthen therapy and prevention of TBI, or computational models of repetitive head injuries.

Assessing Prevalence of TBI in a Community Setting

Background: Traumatic brain injury (TBI) is often under-reported and thus under-recognized by clinicians. Reports of TBI prevalence have been widely variable based on the methods of data collection and definition of TBI. This study investigates the prevalence of TBI using the Ohio State University TBI Identification Method (OSU TBI-ID), a reliable and valid structured interview designed to elicit lifetime history of TBI. We also assessed relationships between TBI and psychiatric illnesses. Identifying prevalence and effects of TBI on mental health is critical to providing personalized, higher-quality care for psychiatric patients in community settings. 
 
 Methods: Patients receiving mental health care at the IUSM Psychiatry Residency Clinic in Vincennes, Indiana were asked to participate in a research study assessing history of head or neck injuries. Patients attended their regularly scheduled appointments with resident physicians, and 2–5-minute TBI screenings were conducted during or immediately after their appointment. Following the interview, patient charts were reviewed for documentation of prior TBI and all current psychiatric diagnoses. 
 
 Results: Prevalence of TBI was reported at 62.3% among patients receiving psychiatric care. 87 total TBI events were recorded, including repetitive TBI events, after 77 patient interviews. The most common cause of acute TBI was vehicular accident. The most common cause of repetitive TBI was sports injury. Of the 87 TBIs, only 5 TBI events were recorded in patient charts. History of TBI was more likely in patients with PTSD as well as substance use disorders, and this was especially evident in patients with repetitive TBI. 
 
 Conclusion and Potential Impact: This study shows that TBI is quite common among psychiatric patients and is vastly under-reported in patient charts. Increasing clinician awareness of TBI history in their patients is critical to providing high-quality care, and the OSU TBI-ID provides an efficient way to screen patients for TBI.

Cerebral microbleeds in traumatic brain injury associated with differential risk factors and clinical outcomes: the PREVENT‐Dementia study

AbstractBackgroundCerebral microbleeds (CMB) are predictive of increased risk of dementia and stroke. Although commonly regarded as vascular markers, CMB can also stem from non‐vascular aetiologies like head injuries or traumatic brain injury (TBI), although these are often overlooked. Therefore, this study examines CMB in relation to TBI, and their differential causes (i.e., risk factors) and consequences (i.e., clinical outcomes).MethodIn 605 healthy middle‐aged adults (aged 40‐59), CMB were rated on 3T susceptibility weighted imaging (SWI) MRI. TBI was assessed using the Brain Injury Screening Questionnaire (BISQ). TBI+ was defined as at least one blow to the head resulting in loss of consciousness (36.0%; n = 217). Memory was assessed using the COGNITO battery. Interaction analyses examined TBI*CMB interactions on hypertension, gait, and memory. Dominance analysis examined the relative contribution of TBI and vascular risk factors on predicting gait disturbances and memory. All models adjusted for sex, age, education, and study site.ResultTBI was related to higher CMB count (t = 2.06, p = .039), and were more common in males (48.3%) than females (28.0%) (Χ2 = 28.91, p<.001). Number of TBI events related to poorer memory (t = ‐2.62, p = .009) and gait disturbances (t = 3.54, p<.001). Interaction analyses demonstrated that hypertension (t = ‐2.26, p = .024), memory (t = 2.70, p = .007) and gait (t = ‐2.29, p = .023) were less closely related to CMB in individuals with greater number of TBI events, relative to those with fewer TBIs. Regionally, these interactions were significant for lobar CMB, but not deep subcortical CMB. Within the TBI+ group, dominance analysis demonstrated that number of TBI events outperformed vascular risk factors in predicting gait disturbances (Contribution to R2: TBI = 52.9%, vascular risk = 32.6%) and memory (TBI = 28.7%, vascular risk = 1.2%).ConclusionCMB appeared to differ aetiologically and clinically in those with and without TBI. In individuals with TBI, TBI itself was the dominant driver of clinical deficits. When compared to CMB of presumed vascular origins cross‐sectionally, TBI‐related CMB may appear to be less detrimental. However, longitudinal analysis is required to determine how TBI‐related CMB differ in clinical trajectory and downstream pathologies. This study highlights the importance of differentiating between CMB of vascular origins vs. TBI in both research and clinically to aid prognosis and treatment decisions.

Cerebral microbleeds in traumatic brain injury associated with differential risk factors and clinical outcomes: the PREVENT‐Dementia study

AbstractBackgroundCerebral microbleeds (CMB) are predictive of increased risk of dementia and stroke. Although commonly regarded as vascular markers, CMB can also stem from non‐vascular aetiologies like head injuries or traumatic brain injury (TBI), although these are often overlooked. Therefore, this study examines CMB in relation to TBI, and their differential causes (i.e., risk factors) and consequences (i.e., clinical outcomes).MethodIn 605 healthy middle‐aged adults (aged 40‐59), CMB were rated on 3T susceptibility weighted imaging (SWI) MRI. TBI was assessed using the Brain Injury Screening Questionnaire (BISQ). TBI+ was defined as at least one blow to the head resulting in loss of consciousness (36.0%; n = 217). Memory was assessed using the COGNITO battery. Interaction analyses examined TBI*CMB interactions on hypertension, gait, and memory. Dominance analysis examined the relative contribution of TBI and vascular risk factors on predicting gait disturbances and memory. All models adjusted for sex, age, education, and study site.ResultTBI was related to higher CMB count (t = 2.06, p = .039), and were more common in males (48.3%) than females (28.0%) (Χ2 = 28.91, p<.001). Number of TBI events related to poorer memory (t = ‐2.62, p = .009) and gait disturbances (t = 3.54, p<.001). Interaction analyses demonstrated that hypertension (t = ‐2.26, p = .024), memory (t = 2.70, p = .007) and gait (t = ‐2.29, p = .023) were less closely related to CMB in individuals with greater number of TBI events, relative to those with fewer TBIs. Regionally, these interactions were significant for lobar CMB, but not deep subcortical CMB. Within the TBI+ group, dominance analysis demonstrated that number of TBI events outperformed vascular risk factors in predicting gait disturbances (Contribution to R2: TBI = 52.9%, vascular risk = 32.6%) and memory (TBI = 28.7%, vascular risk = 1.2%).ConclusionCMB appeared to differ aetiologically and clinically in those with and without TBI. In individuals with TBI, TBI itself was the dominant driver of clinical deficits. When compared to CMB of presumed vascular origins cross‐sectionally, TBI‐related CMB may appear to be less detrimental. However, longitudinal analysis is required to determine how TBI‐related CMB differ in clinical trajectory and downstream pathologies. This study highlights the importance of differentiating between CMB of vascular origins vs. TBI in both research and clinically to aid prognosis and treatment decisions.

Traumatic brain injury induces TDP-43 mislocalization and neurodegenerative effects in tissue distal to the primary injury site in a non-transgenic mouse

Traumatic brain injury (TBI) initiates tissue and cellular damage to the brain that is immediately followed by secondary injury sequalae with delayed and continual damage. This secondary damage includes pathological processes that may contribute to chronic neurodegeneration and permanent functional and cognitive deficits. TBI is also associated with an increased risk of developing neurodegenerative diseases such as Alzheimer’s disease (AD), frontotemporal dementia (FTD), and amyotrophic lateral sclerosis (ALS) as indicated by shared pathological features. For example, abnormalities in the TAR DNA-binding Protein 43 (TDP-43) that includes cytoplasmic mislocalization, cytosolic aggregation, and an increase in phosphorylation and ubiquitination are seen in up to 50% of FTD cases, up to 70% of AD cases, and is considered a hallmark pathology of ALS occurring in > 97% of cases. Yet the prevalence of TDP-43 pathology post-TBI has yet to be fully characterized. Here, we employed a non-transgenic murine controlled cortical injury model of TBI and observed injury-induced hallmark TDP-43 pathologies in brain and spinal cord tissue distal to the primary injury site and did not include the focally damaged tissue within the primary cortical injury site. Analysis revealed a temporal-dependent and significant increase in neuronal TDP-43 mislocalization in the cortical forebrain rostral to and distant from the primary injury site up to 180 days post injury (DPI). TDP-43 mislocalization was also detected in neurons located in the ventral horns of the cervical spinal cord following a TBI. Moreover, a cortical layer-dependent affect was identified, increasing from superficial to deeper cortical layers over time from 7 DPI up to 180 DPI. Lastly, RNAseq analysis confirmed an injury-induced misregulation of several key biological processes implicated in neurons that increased over time. Collectively, this study demonstrates a connection between a single moderate TBI event and chronic neurodegenerative processes that are not limited to the primary injury site and broadly distributed throughout the cortex and corticospinal tract.

Predictors of Mortality and Functional recovery after severe traumatic brain injury: protocol for a prospective cohort study

Introduction: traumatic brain injury is a global public health problem due to its severity and high rates of morbimortality worldwide. Identifying predictors associated with increased mortality and unfavorable functional outcomes after the traumatic brain injury event is crucial for minimizing morbidity and mortality rates. Therefore, this study aims to establish a protocol to investigate the predictors of mortality and functional recovery after severe traumatic brain injury in Brazil. Methods: The study will include all patients admitted for severe traumatic brain injury (Glasgow Coma Scale ≤ 8) at the State Hospital of Urgency and Emergency, which is the referral trauma hospital of Espirito Santo. The outcomes of interest are hospital mortality and functional recovery 24 months after hospital discharge. Subjects will be followed up at seventy-two hours, three months, six months, twelve months, and twenty-four months after the trauma. Morbidity will be determined by assessing: 1) the level of motor and cognitive disability, 2) functional impairment and quality of life, and 3) aspects of rehabilitation treatment. Additionally, the traumatic brain injury load, estimated by the years of life lost, will be calculated. Discussion: the results of this study will help identify variables that can predict morbidity and mortality, as well as diagnostic and therapeutic targets for patients with severe traumatic brain injury. Furthermore, the findings will have practical implications for: 1) the development of public policies, 2) investments in hospital infrastructure 3) understanding the socioeconomic impact of functional loss in the individuals. Study registration: the study received approval from the Ethics Committee of the Federal University of Espirito Santo under protocol number 4.222.002 on August 18, 2020.

Risk of secondary stroke subsequent to restarting aspirin in chronic stroke patients suffering from traumatic brain injury in Taiwan

Traumatic brain injury (TBI) is a silent epidemic that has been easily ignored. The safety and efficacy of restarting antiplatelet therapy after encountering traumatic brain injury (TBI) events remain a challenge. We explored the outcomes of restarting aspirin use on secondary stroke and mortality in patients with chronic stroke 4 weeks after suffering from a TBI episode in Taiwan. This study analyzed data from the National Health Insurance Research Database from January 2000 to December 2015. Overall, 136,211 individuals diagnosed with chronic stroke who suffered from acute TBI and received inpatient service were enrolled. The study outcomes were a competing risk of secondary stroke (ischemic and hemorrhagic) hospitalization and all-cause mortality. We identified a case group of 15,035 patients with chronic stroke (mean [SD] age of 53.25 [19.74] years; 55.63% male) who restarted aspirin use 4 weeks after suffering from TBI and a control group of 60,140 patients with chronic stroke (mean [SD] age of 53.12 [19.22] years; 55.63% male) who discontinued aspirin use after suffering from TBI. The risk of hospitalization of secondary ischemic stroke [adjusted hazard ratio (aHR) 0.694; 95% confidence interval (CI) 0.621–0.756; P < 0.001] and hemorrhagic stroke (aHR 0.642; 95% CI 0.549–0.723; P < 0.001) and all-cause mortality (aHR 0.840; 95% CI 0.720–0.946; P < 0.001) significantly decreased in patients with chronic stroke restarting aspirin use 1 month after suffering from TBI events (including intracranial hemorrhage) in comparison with the control subjects, regardless of those with or without diabetes mellitus, chronic kidney disease, myocardial infarction, atrial fibrillation, clopidogrel use, and dipyridamole use. Restarting aspirin use could lower the risks of secondary stroke (ischemic and hemorrhagic) hospitalization and all-cause mortality in patients with chronic stroke 1 month after suffering from TBI episodes.

A model of traumatic brain injury in rats is influenced by neuroprotection of diurnal variation which improves motor behavior and histopathology in white matter myelin

Traumatic brain injury (TBI) represents a significant public health concern and has been associated with high rates of morbidity and mortality. TBI generates two types of brain damage: primary and secondary. Secondary damage originates a series of pathophysiological processes, which include metabolic crisis, excitotoxicity, and neuroinflammation, which have deleterious consequences for neuronal function. However, neuroprotective mechanisms are also activated. The balance among these tissue responses, and its variations throughout the day determines the fate of the damage tissue. We have demonstrated less behavioral and morphological damage when a rat model of TBI was induced during the light hours of the day.Moreover, here we show that rats subjected to TBI in the dark lost less body weight than those subjected to TBI in the light, despite no change in food intake. Besides, the rats subjected to TBI in the dark had better performance in the beam walking test and presented less histological damage in the corpus callosum and the cingulum bundle, as shown by the Klüver-Barrera staining.Our results suggest that the time of day when the injury occurs is important. Thus, this data should be used to evaluate the pathophysiological processes of TBI events and develop better therapies.

Analysis of Nitrogen Balance Test in Patients With Traumatic Brain Injury

Background: This study aimed to analyze the catabolic phases of patients with traumatic brain injury (TBI) by performing the Nitrogen Balance Test (NB Test).Methods: This single-centered, retrospective study included data from 292 patients who underwent NB tests from 2019 to 2022 and categorized them as TBI and Non-TBI groups. The basic clinical factors (gender, age, and initial GCS), critical care factors (APACHE, SOFA, and ICU stay days), and outcomes (GOS). The trend of the NB test was investigated in all groups and analyzed the statistical correlation of the NB test was with severity, critical care factors, and outcomes. Results: A total of 52 patients were found to have TBI. The 26 out of 52 TBI patients underwent the second NB test 1 week after the first NB test. The deficiency of protein calculated was 24.375 g. There was a significant statistical difference of NB test patterns between the non-TBI and TBI patients.Conclusion: Physicians should be aware of the catabolic phases of acute TBI events indicating notable protein loss in the patients. Therefore, we should consider the additional supply of protein when managing TBI patients.

Differences in Risk of Alzheimer's Disease Following Later-Life Traumatic Brain Injury in Veteran and Civilian Populations.

To directly compare the effect of incident age 68+ traumatic brain injury (TBI) on the risk of diagnosis of clinical Alzheimer's disease (AD) in the general population of older adults, and between male veterans and nonveterans; to assess how this effect changes with time since TBI. Community-dwelling traditional Medicare beneficiaries 68 years or older from the Health and Retirement Study (HRS). Fine-Gray models combined with inverse-probability weighting were used to identify associations between incident TBI, post-TBI duration, and TBI treatment intensity, with a diagnosis of clinical AD dementia. The study included 16 829 older adults followed over the 1991-2015 period. For analyses of veteran-specific risks, 4281 veteran males and 3093 nonveteran males were identified. Analysis of veteran females was unfeasible due to the age structure of the population. Information on occurrence(s) of TBI, and onset of AD and risk-related comorbidities was constructed from individual-level HRS-linked Medicare claim records while demographic and socioeconomic risk factors were based on the survey data. Later-life TBI was strongly associated with increased clinical AD risk in the full sample (pseudo-hazard ratio [HR]: 3.22; 95% confidence interval [CI]: 2.57-4.05) and in veteran/nonveteran males (HR: 5.31; CI: 3.42-7.94), especially those requiring high-intensity/duration care (HR: 1.58; CI: 1.29-1.91). Effect magnitude decreased with time following TBI (HR: 0.72: CI: 0.68-0.80). Later-life TBI was strongly associated with increased AD risk, especially in those requiring high-intensity/duration care. Effect magnitude decreased with time following TBI. Univariate analysis showed no differences in AD risk between veterans and nonveterans, while the protective effect associated with veteran status in Fine-Gray models was largely due to differences in demographics, socioeconomics, and morbidity. Future longitudinal studies incorporating diagnostic procedures and documentation quantifying lifetime TBI events are necessary to uncover pathophysiological mediating and/or moderating mechanisms between TBI and AD.

Determining the value of early measurement of interleukin-10 in predicting the absence of brain lesions in CT scans of patients with mild traumatic brain injury

Blood-based biomarkers were recently proposed as predictors of traumatic brain injury (TBI) outcomes. This would be a critical step forward since the majority of TBI events are mild and structural brain damage in this group may be missed by current brain imaging methods. We sought to determine the performance of early measurement of interleukin-10 (IL-10) to distinguish computed tomography (CT)-positive from negative patients with mild TBI. We designed a single-center prospective observational study, which enrolled consecutive patients classed with mild TBI according to Glasgow Coma Scale [GCS] scores and appearance of at least one clinical symptom. Serum IL-10 levels were measured <3 h post hospital admission. The performance of IL-10 levels in correctly classifying patients was evaluated. IL-10 levels were significantly higher in the group with positive CT scans (p < 0.001). With sensitivity set at 100%, the specificity of IL-10 was only 38.1%. However, the specificities of IL-10 for prediction of negative and positive cases increased to 59% and 49%, respectively, when both parameters were assessed within 90 min of admission. For mild TBI patients between 36 and 66 years, classification performance increased significantly at the 100% sensitivity level with a specificity of 93%. Our results suggest that IL-10 may be an easily accessible clinically useful diagnostic biomarker that can distinguish between mild TBI patients with and without structural brain damage with higher effectiveness when lower times of blood sampling are employed and patients are between 36 and 66 years of age.

Persistent hypersomnia following repetitive mild experimental traumatic brain injury: Roles of chronic stress and sex differences.

Traumatic brain injury (TBI) is often more complicated than a single head injury. An extreme example of this point may be military service members who experience a spectrum of exposures over a prolonged period under stressful conditions. Understanding the effects of complex exposures can inform evaluation and care to prevent persistent symptoms. We designed a longitudinal series of non-invasive procedures in adult mice to evaluate the effects of prolonged mild stress and head injury exposures. We assessed anxiety, depression, and sleep-wake dysfunction as symptoms that impact long-term outcomes after mild TBI. Unpredictable chronic mild stress (UCMS) was generated from a varied sequence of environmental stressors distributed within each of 21 days. Subsequently, mice received a mild blast combined with closed-head mild TBI on 5 days at 24-h intervals. In males and females, UCMS induced anxiety without depressive behavior. A major finding was reproducible sleep-wake dysfunction through 6- to 12-month time points in male mice that received UCMS with repetitive blast plus TBI events, or surprisingly after just UCMS alone. Specifically, male mice exhibited hypersomnia with increased sleep during the active/dark phase and fragmentation of longer wake bouts. Sleep-wake dysfunction was not found with TBI events alone, and hypersomnia was not found in females under any conditions. These results identify prolonged stress and sex differences as important considerations for sleep-wake dysfunction. Furthermore, this reproducible hypersomnia with impaired wakefulness is similar to the excessive daytime sleepiness reported in patients, including patients with TBI, which warrants further clinical screening, care, and treatment development.

Integrating unsupervised and supervised learning techniques to predict traumatic brain injury: A population-based study

This work aimed to identify pre-existing health conditions of patients with traumatic brain injury (TBI) and develop predictive models for the first TBI event and its external causes by employing a combination of unsupervised and supervised learning algorithms. We acquired up to five years of pre-injury diagnoses for 488,107 patients with TBI and 488,107 matched control patients who entered the emergency department or acute care hospitals between April 1st, 2002, and March 31st, 2020. Diagnoses were obtained from the Ontario Health Insurance Plan (OHIP) database which contains province-wide claims data by physicians in Ontario, Canada for inpatient and outpatient services. A screening process was conducted on the OHIP diagnostic codes to limit the subsequent analysis to codes that were predictive of TBI, which concluded that 314 codes were significantly associated with TBI. The Latent Dirichlet Allocation (LDA) model was applied to the diagnostic codes and generated an optimal number of 19 topics that concur with published literature but also suggest other unexplored areas. Estimated word-topic probabilities from the LDA model helped us detect pre-morbid conditions among patients with TBI by uncovering the underlying patterns of diagnoses, meanwhile estimated document-topic probabilities were utilized in variable creation as form of a dimension reduction. We created 19 topic scores for each patient in the cohort which were utilized along with socio-demographic factors for Random Forest binary classifier models. Test set performances evaluated using area under the receiver operating characteristic curve (AUC) were: TBI event (AUC = 0.85), external cause of injury: falls (AUC = 0.85), struck by/against (AUC = 0.83), cyclist collision (AUC = 0.76), motor vehicle collision (AUC = 0.83). Our analysis successfully demonstrated the feasibility of using machine learning to predict TBI due to various external causes and identified the most important factors that contribute to this prediction.

GFAP as an immunohistochemical marker in traumatic brain injuries

Introduction: Head injury recently replaced by the new term: traumatic brain injury (TBI) is a common cause of death worldwide and many researchers report it as a global health problem. The main cause of TBI is associated with various forms of violent, domestic, or accidental death. In these cases, an autopsy is mandatory to understand the immediate cause of death and its relationship to the TBI. Our study aimed to understand the general histopathological changes and expression of various immunohistochemical markers in TBI at medico-legal autopsies. Material and methods: Autopsies were performed on 20 cadavers whose cause of death was a traumatic brain injury and 20 cadavers with sudden deaths. The postmortem examination was performed by a forensic expert under the Virchow method. After labeling of brain tissues and fixation in formalin solution, they were transported to the histological department. The tissues were stained with hematoxylin and eosin (H&amp;E) for histological assessment. Additional slices were taken for immunohistochemical examination. In our research, we used primary antibodies for GFAP, Ki67, and NeuN immunohistochemical markers. Results: The main histological changes in TBI were subarachnoid hemorrhages, perineuronal and perivascular edema, small foci of erythrocyte extravasation, and capillary stasis. From the immunohistochemical markers, GFAP showed some specific and interesting changes. Conclusions: Our data show that GFAP can serve as an immunohistochemical marker for TBI and its immunohistochemical staining changes can be a sequence of time-dependent events in TBI.

The alteration of serum bile acid profile among traumatic brain injury patients: a small-scale prospective study.

Traumatic brain injury is one of the major causes of morbidity and mortality worldwide. With the development of bile acids as a potential treatment, to identify the influence of traumatic brain injury on bile acid metabolism shows growing importance. This present study did a preliminary exploration of the bile acid profile alteration among traumatic brain injury patients. In total, 14 patients and 7 healthy volunteers were enrolled. The bile acid profile of the blood samples were detected by an Ultra-performance Liquid Chromatography Mass Spectrometer/Mass Spectrometer system. It was found that 6 bile acids were statistically decreased in traumatic brain injury patients comparing with healthy volunteers: glycocholic acid (median level 44.4 ng/ml vs 98.7 ng/ml, p = 0.003), taurocholic acid (median level 10.9 ng/ml vs 19.5 ng/ml, p = 0.006), glycoursodeoxycholic acid (median level 17.4 ng/ml vs 71.4 ng/ml, p = 0.001), ursodeoxycholic acid (median level <1 ng/ml vs 32.4 ng/ml, p = 0.002), taurochenodeoxycholic acid (median level <1 ng/ml vs 53.6 ng/ml, p = 0.003) and glycochenodeoxycholic acid (GCDCA, median level 160 ng/ml vs 364 ng/ml, p<0.001). In conclusion, traumatic brain injury events are able to induce bile acid metabolism alteration in plasma and might cause reduction in glycocholic, taurocholic, glycoursodeoxycholic, ursodeoxycholic, taurochenodeoxycholic and glycochenodeoxycholic acid levels.