Moderate Traumatic Brain Injury Research Articles

An EEG-Based Neuroplastic Approach to Predictive Coding in People With Schizophrenia or Traumatic Brain Injury.

Despite different etiologies, people with schizophrenia (SCZ) or with traumatic brain injury (TBI) both show aberrant neuroplasticity. One neuroplastic mechanism that may be affected is prediction error coding. We used a roving mismatch negativity (rMMN) paradigm which uses different lengths of standard tone trains and is optimized to assess predictive coding. Twenty-five SCZ, 22 TBI (mild to moderate), and 25 healthy controls were assessed. We used a frequency-deviant rMMN in which the number of standards preceding the deviant was either 2, 6, or 36. We evaluated repetition positivity to the standard tone immediately preceding a deviant tone (repetition positivity [RP], to assess formation of the memory trace), deviant negativity to the deviant stimulus (deviant negativity [DN], which reflects signaling of a prediction error), and the difference wave between the 2 (the MMN). We found that SCZ showed reduced DN and MMN compared with healthy controls and with people with mild to moderate TBI. We did not detect impairments in any index (RP, DN, or MMN) in people with TBI compared to controls. Our findings suggest that prediction error coding assessed with rMMN is aberrant in SCZ but intact in TBI, though there is a suggestion that severity of head injury results in poorer prediction error coding.

Neuroinflammation Plays a Potential Role in the MedullaOblongata after Moderate Traumatic Brain Injury in Mice as Revealed by Nontargeted Metabonomics Analysis.

Moderate traumatic brain injury (mTBI) involves a series of complex pathophysiological processes in not only the area in direct contact with mechanical violence but also other brain regions far from the injury site, which may be important factors influencing subsequent neurological dysfunction or death. The medulla oblongata (MO) is a key area for the maintenance of basic respiratory and circulatory functions, whereas the pathophysiological processes after mTBI have rarely drawn the attention of researchers. In this study, we established a closed-head cortical contusion injury model, identified 6 different time points that covered the acute, subacute and chronic phases, and then used nontargeted metabolomics to identify and analyse the changes in differential metabolites (DMs) and metabolic pathways in the MO region. Our results showed that the metabolic profile of the MO region underwent specific changes over time: harmaline, riboflavin and dephospho-coenzyme A were identified as the key DMs and play important roles in reducing inflammation, enhancing antioxidation and maintaining homeostasis. Choline and glycerophospholipid metabolism were identified as the key pathways related to the changes in MO metabolism at different phases. In addition, we confirmed increases in the levels of inflammatory factors and the activation of astrocytes and microglia by Western blot and immunofluorescence staining, and these findings were consistent with the nontargeted metabolomics results. These findings suggest that neuroinflammation plays a central role in MO neuropathology after mTBI and provide new insights into the complex pathophysiologic mechanisms involved after mTBI.

Serum exosomes miR-206 and miR-549a-3p as potential biomarkers of traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide. However, effective diagnostic, therapeutic and prognostic biomarkers are still lacking. Our research group previously revealed through high-throughput sequencing that the serum exosomes miR-133a-3p, miR-206, and miR-549a-3p differ significantly in severe TBI (sTBI), mild or moderate TBI (mTBI), and control groups. However, convincing experimental evidence is lacking. To solve this problem, we used qPCR in this study to further verify the expression levels of serum exosomes miR-133a-3p, miR-206 and miR-549a-3p in TBI patients. The results showed that the serum exosomes miR-206 and miR-549a-3p showed good predictive value as biomarkers of TBI. In addition, in order to further verify whether serum exosomes miR-206 and miR-549a-3p can be used as potential biomarkers in patients with TBI and to understand the mechanism of their possible effects, we further determined the contents of SOD, BDNF, VEGF, VEGI, NSE and S100β in the serum of TBI patients. The results showed that, serum exosomes miR-206 and miR-549a-3p showed good correlation with BDNF, NSE and S100β. In conclusion, serum exosomes miR-206 and miR-549a-3p have the potential to serve as potential biomarkers in patients with TBI.

Distinct Serum GFAP and Nf-L Time-Courses after Rapid Head Rotations.

Traumatic brain injury (TBI) causes significant neurophysiological deficits and is typically associated with rapid head accelerations common in sports-related incidents and automobile accidents. There are over 1.5 million TBIs in the US each year, with children aged 0-4 being particularly vulnerable. TBI diagnosis is currently achieved through interpretation of clinical signs and symptoms and neuroimaging; however, there is increasing interest in minimally invasive fluid biomarkers to detect TBI objectively across all ages. Preclinical porcine models offer controlled conditions to evaluate TBI with known biomechanical conditions and without co-morbidities. The objective of the current study was to establish pediatric porcine healthy reference ranges (RR) of common human serum TBI biomarkers and to report their acute time-course after non-impact rotational head injury. A retrospective analysis was completed to quantify biomarker concentrations in porcine serum samples collected from four-week-old female (n = 215) and uncastrated male (n = 6) Yorkshire piglets. Subjects were assigned to one of three experimental groups (sham, sagittal-single, sagittal-multiple) or to a baseline only group. A rapid non-impact rotational (RNR) head injury model was used to produce mild to moderate TBI in piglets following a single rotation and moderate to severe TBI following multiple rotations. The Quanterix Simoa Human Neurology 4-Plex A (N4PA) assay was used to quantify glial fibrillary acidic protein (GFAP), neurofilament light (Nf-L), tau, and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1). The 95% healthy RR for females were calculated and validated for GFAP (6.3-69.4 pg/mL), Nf-L (9.5-67.2 pg/mL), and UCH-L1 (3.8-533.7 pg/mL). Rising early, GFAP increased significantly above the healthy RR for sagittal-single (to 164 and 243 pg/mL) and increased significantly higher in sagittal-multiple (to 494 and 413 pg/mL) groups at 30 min and 1 h post-injury, respectively, returning to healthy RR ranges by 1-week post-injury. Rising later, Nf-L increased significantly above the healthy RR by 1 day in sagittal-single (to 69 pg/mL) and sagittal-multiple groups (to 140 pg/mL) and rising further at 1 week (single = 231 pg/mL, multiple = 481 pg/mL). Sagittal-single and sagittal-multiple UCH-L1 serum samples did not differ from shams or the healthy RR. Sex differences were observed but inconsistent. Serum GFAP and Nf-L levels had distinct time-courses following head rotations in piglets, and both corresponded to load exposure. We conclude that serum GFAP and Nf-L offer promise for early TBI diagnosis and intervention decisions for TBI and other neurological trauma.

Cisternostomy is not beneficial to reduce the occurrence of post-traumatic hydrocephalus in Traumatic Brain Injury.

The Cisternostomy is a novel surgical concept in the treatment of Traumatic Brain Injury (TBI), which can effectively drain the bloody cerebrospinal fluid from the skull base cistern, reduce the intracranial pressure, and improve the return of bone flap, but its preventive role in post-traumatic hydrocephalus (PTH) is unknow. The purpose of this paper is to investigate whether Cisternostomy prevents the occurrence of PTH in patients with moderate and severe TBI. A retrospective analysis of clinical data of 86 patients with moderate and severe TBI from May 2019 to October 2021 was carried out in the Brain Trauma Center of Tianjin Huanhu Hospital. Univariate analysis was performed to examine the gender, age, preoperative Glasgow Coma Scale (GCS) score, preoperative Rotterdam CT score, decompressive craniectomy rate, intracranial infection rate, the incidence of subdural fluid, and incidence of hydrocephalus in patients between the Cisternostomy group and the non-Cisternostomy surgery group. we also analyzed the clinical outcome indicators like GCS at discharge,6month GOS-E and GOS-E ≥ 5 in two groups.Additionaly, the preoperative GCS score, decompressive craniectomy rate, age, and gender of patients with PTH and non hydrocephalus were compared. Further multifactorial logistic binary regression was performed to explore the risk factors for PTH. Finally, we conducted ROC curve analysis on the statistically significant results from the univariate regression analysis to predict the ability of each risk factor to cause PTH. The Cisternostomy group had a lower bone flap removal rate(48.39% and 72.73%, p = 0.024)., higer GCS at discharge(11.13 ± 2.42 and 8.93 ± 3.31,p = 0.000) and better 6month GOS-E(4.55 ± 1.26 and 3.95 ± 1.18, p = 0.029)than the non-Cisternostomy group However, there was no statistical difference in the incidence of hydrocephalus between the two groups (25.81% and 30.91%, p = 0.617). Moreover, between the hydrocephalus group and no hydrocephalus group,there were no significant differences in the incidence of gender, age, intracranial infection, and subdural fluid. While there were statistical differences in peroperative GCS score, Rotterdam CT score, decompressive craniectomy rate, intracranial infection rate, and the incidence of subdural fluid in the two groups, there was no statistical difference in the percentage of cerebral cisterns open drainage between the hydrocephalus group and no hydrocephalus group (32.00% and 37.70%, p = 0.617). Multifactorial logistic binary regression analysis results revealed that the independent risk factors for PTH were intracranial infection (OR = 18.460, 95% CI: 1.864-182.847 p = 0.013) and subdural effusion (OR = 10.557, 95% CI: 2.425-35.275 p = 0.001). Further, The ROC curve analysis showed that peroperative GCS score, Rotterdam CT score and subdural effusion had good ACU(0.785,0.730,and 0.749), with high sensitivity and specificity to predict the occurrence of PTH. Cisternostomy may decrease morbidities associated with removal of the bone flap and improve the clinical outcome, despite it cannot reduce the disability rate in TBI patients.Intracranial infection and subdural fluid were found to be the independent risk factors for PTH in patients with TBI,and the peroperative GCS score, Rotterdam CT score and subdural effusion had higher sensitivity and specificity to predict the occurrence of PTH. And more importantly, no correlation was observed between open drainage of the cerebral cisterns and the occurrence of PTH, indicating that Cisternostomy may not be beneficial in preventing the occurrence of PTH in patients with moderate and severe TBI.

Readiness for hospital discharge perceived by caregivers of patients with traumatic brain injury: A cross-sectional study.

There is a growing emphasis on evaluating discharge readiness, particularly for those involved in the care of patients in transition. Caregivers supporting individuals with traumatic brain injury are a specific focus due to the potential impact of adequate discharge preparation on patient recovery and post-discharge outcomes. This research aimed to evaluate the preparedness of caregivers for the discharge of patients with moderate or severe traumatic brain injury from the hospital. This cross-sectional study was carried out in a tertiary hospital in Indonesia from January to April 2023 using the Indonesian adaptation of the Preparedness for Caregiving Scale. The study comprised seventy-four caregivers of individuals with traumatic brain injury, chosen through a purposive sampling approach based on pre-established inclusion and exclusion criteria. Data collection involved a questionnaire covering caregiver information (gender, age, education level, income, and psychological status) and discharge readiness. Descriptive statistics and correlation analyses, employing Pearson and chi-square, were conducted. Most caregivers were female (83.8%), spouses of patients (50%), and had a moderate education level (52.7%). The average age of caregivers was 43.7 ± 8.7 years, with an average duration of patient care of 4.22 ± 1.2 days and a monthly income of 220 US dollars. The mean score for readiness for hospital discharge was low (10.08 ± 1.91), indicating that caregivers were not adequately prepared for discharge. Age and education were significant factors (p <0.05) related to hospital discharge readiness. This study emphasizes the importance of assessing caregiver readiness for the discharge of patients with traumatic brain injury from the hospital. Findings indicate a concerning trend of inadequate preparedness among caregivers, with factors such as age and education level significantly influencing readiness. The predominance of female caregivers, often spouses of patients, indicates the need for tailored support strategies. Prioritizing caregiver preparation and support, especially by nurses, is crucial for optimizing patient recovery and post-discharge outcomes.

Elucidating a genomic signature associated with behavioral and executive function after moderate to severe pediatric TBI: a systems biology informed approach

Introduction: There is significant unexplained variability in behavioral and executive functioning after pediatric traumatic brain injury (TBI). Prior research indicates that there are likely genetic contributions; however, current research is limited. The purpose of this study is to use a systems biology informed approach to characterize the genomic signature related to behavioral and executive functioning ∼12 months after moderate through severe TBI in children.Methods: Participants were from two prospective cohorts of children with severe TBI (Cohort #1) and moderate-severe TBI and an orthopedic injury (OI) group (Cohort #2). Participants included 196 children (n = 72 and n = 124 total from each respective cohort), ranging in age between 0–17 years at the time of injury. In total, 86 children had severe TBI, 49 had moderate TBI, and 61 had an OI. Global behavioral functioning assessed via the Child Behavior Checklist and executive function assessed via the Behavioral Rating Inventory of Executive Function at ∼ 12 months post injury served as outcomes. To test for a genomic signature, we compared the number of nominally significant (p &amp;lt; 0.05) polymorphisms associated with the outcomes in our systems biology identified genes to a set 10,000 permutations using control genes (e.g., not implicated by systems biology). We used the ToppFun application from Toppgene Suite to identify enriched biologic processes likely to be associated with behavioral and executive function outcomes.Results: At 12 months post injury, injury type (TBI vs OI) by polymorphism interaction was significantly enriched in systems biology selected genes for behavioral and executive function outcomes, suggesting these genes form a genomic signature. Effect sizes of the associations from our genes of interest ranged from .2–.5 for the top 5% of variants. Systems biology analysis of the variants associated with the top 5% effect sizes indicated enrichment in several specific biologic processes and systems.Discussion: Findings indicate that a genomic signature may explain heterogeneity of behavioral and executive outcomes after moderate and severe TBI. This work provides the foundation for constructing genomic signatures and integrating systems biology and genetic information into future recovery, prognostic, and treatment algorithms.

Long-term outcome of pediatric head injuries – A five-year follow-up

Objectives: Traumatic brain injury (TBI) disrupts the developing brain in the pediatric population. This study aims to look at the outcomes of moderate and severe TBI over a five-year follow-up to look for the long-term sequelae of head injury in the pediatric population. Materials and Methods: A prospective observational study was conducted after obtaining the permission of the Institutional Ethics Committee with the primary study participants admitted between 2015 and 2017 with follow-up extending up to 2022 in 118 pediatric patients, aged between 1 and 15 years who required admission in the pediatric intensive care unit with moderate and severe TBI. Results: Language impairment was noted in 33.63% (n = 37) patients during early follow-up, and 12 of them continued to have impaired language skills and communication at the end of five years. With regard to school functioning, children had more difficulty in the arithmetic domain (n = 33) compared to language domains (n = 17). While the parents noted improvements in scholastic performances, some degree of difficulty in learning was noted in most of the children, who sustained TBI. Despite these difficulties, 27 out of 41 participants, who gave their higher secondary examinations have gone on to pursue undergraduate courses in colleges. Conclusion: Our study indicates that over the passage of time, children tend to have a reasonable chance at recovery, and with the potential for plasticity, early and aggressive rehabilitative services may enable the child to have a decent quality of life and in selected cases, even an independent life.

Factors Associated With Time to Decannulation in Patients With Tracheostomy Following Severe Traumatic Brain Injury.

Prolonged tracheal tube placement following severe traumatic brain injury (TBI) can cause serious complications. Safe removal requires sufficient ability for independent breathing and airway protection. Thus, identifying important factors for time to removal of the tracheal tube (decannulation) is essential for safe and efficient weaning. This study aimed to identify significant factors for time to decannulation in a Danish population of subjects with tracheostomy after TBI. This was a retrospective register-based cohort study. Subjects with moderate and severe TBI and a tracheal tube were selected from the Danish Head Trauma Database between 2011-2021. Time to decannulation was calculated as time from injury to decannulation. Associations between selected explanatory variables representing demographic and clinical characteristics and time to decannulation were analyzed using linear regression models. A total 324 subjects were included with a median of 44 d to decannulation. Primary analysis found that an improvement in swallowing ability during the initial 4 weeks of rehabilitation was associated with an 8.2 d reduction in time to decannulation (95% CI -12.3 to -4.2, P < .001). Change in overall sensorimotor ability reduced time to decannulation by 0.94 (95% CI -0.78 to -0.10, P = .03) d. Change in cognitive abilities from rehab admission to 4-week follow-up did not significantly affect the number of days to decannulation (P = .66). Secondary analysis showed pneumonia was associated with the largest estimated increase of 24.4 (95% CI 15.9-32.9, P < .001) d and that increased cognitive functioning at rehabilitation admission was associated with a significant reduction in time to decannulation. This study found that a change in swallowing ability is a potentially significant factor for reducing time to decannulation. Identifying factors that could explain differences in time to decannulation is essential for patient outcomes, especially if these factors are modifiable and could be targeted in rehabilitation and treatment.

Early Seizure Prophylaxis in Mild and Moderate Traumatic Brain Injury

Guidelines recommend seizure prophylaxis for early posttraumatic seizures (PTS) after severe traumatic brain injury (TBI). Use of antiseizure medications for early seizure prophylaxis after mild or moderate TBI remains controversial. To determine the association between seizure prophylaxis and risk reduction for early PTS in mild and moderate TBI. PubMed, Google Scholar, and Web of Science (January 1, 1991, to April 18, 2023) were systematically searched. Observational studies of adult patients presenting to trauma centers in high-income countries with mild (Glasgow Coma Scale [GCS], 13-15) and moderate (GCS, 9-12) TBI comparing rates of early PTS among patients with seizure prophylaxis with those without seizure prophylaxis. The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) reporting guidelines were used. Two authors independently reviewed all titles and abstracts, and 3 authors reviewed final studies for inclusion. A meta-analysis was performed using a random-effects model with absolute risk reduction. The main outcome was absolute risk reduction of early PTS, defined as seizures within 7 days of initial injury, in patients with mild or moderate TBI receiving seizure prophylaxis in the first week after injury. A secondary analysis was performed in patients with only mild TBI. A total of 64 full articles were reviewed after screening; 8 studies (including 5637 patients) were included for the mild and moderate TBI analysis, and 5 studies (including 3803 patients) were included for the mild TBI analysis. The absolute risk reduction of seizure prophylaxis for early PTS in mild to moderate TBI (GCS, 9-15) was 0.6% (95% CI, 0.1%-1.2%; P = .02). The absolute risk reduction for mild TBI alone was similar 0.6% (95% CI, 0.01%-1.2%; P = .04). The number needed to treat to prevent 1 seizure was 167 patients. Seizure prophylaxis after mild and moderate TBI was associated with a small but statistically significant reduced risk of early posttraumatic seizures after mild and moderate TBI. The small absolute risk reduction and low prevalence of early seizures should be weighed against potential acute risks of antiseizure medications as well as the risk of inappropriate continuation beyond 7 days.

Lesion Frequency Distribution Maps of Traumatic Axonal Injury on Early Magnetic Resonance Imaging after Moderate and Severe Traumatic Brain Injury and Associations to 12 Months Outcome.

Traumatic axonal injury (TAI) is a common finding on MRI in patients with moderate - severe traumatic brain injury (TBI), and the burden of TAI is associated with outcome in this patient group. Lesion mapping offers a way to combine imaging findings from numerous individual patients into common lesion maps where the findings from a whole patient cohort can be assessed. The aim of this study was to evaluate the spatial distribution of traumatic axonal injury (TAI) lesions on different MRI sequences and its associations to outcome with use of lesion mapping. 269 patients (8-70 years) with moderate or severe TBI traumatic brain injury and magnetic resonance imaging (MRI) within six weeks after injury were prospectively included. TAI lesions were evaluated and manually segmented on fluid-attenuated inversed recovery (FLAIR), diffusion weighted imaging (DWI) and either T2* gradient echo (T2*GRE) or susceptibility weighted imaging (SWI). The segmentations were registered to the Montreal Neurological Institute space and combined to lesion frequency distribution maps. Outcome was assessed with Glasgow Outcome Scale Extended (GOSE) score at 12 months. The frequency and distribution of TAI was assessed qualitatively by evaluated visually reading. Univariable associations to outcome was assessed qualitatively by visual reading evaluated visually and also quantitatively with use of voxel-based lesion-symptom mapping (VLSM). The highest frequency of TAI was found in the posterior half of corpus callosum. The frequency of TAI was higher in the frontal- and temporal lobes than in the parietal- and occipital lobes, and in the upper parts of the brainstem than in the lower. On At the group level, all the voxels in mesencephalon had TAI on FLAIR. The patients with poorest outcome (GOSE scores ≤ 4) had higher frequencies of TAI. On VLSM, poor outcome was associated with TAI lesions univariable associations to outcome was found bilaterally in the splenium, and in the right side of tectum, tegmental mesencephalon and pons. With this study, we present lesion frequency distribution maps of TAI in a large cohort of patients with moderate and severe TBI. In conclusion, we found the highest higher frequency of TAI in posterior corpus callosum, and TAI in splenium, mesencephalon and pons were associated to with poor outcome. In the future, integration into picture archiving systems would enable comparison of individual patient maps with If lesion frequency distribution maps containing outcome information based on imaging findings from numerous patients in the future can be compared to the imaging findings from individual patients, it would offer a new tool in the clinical work-up and outcome prediction of TBI patient. Key Words: Brain injuries, traumatic; Diffuse axonal injury; Neuroimaging; Brain mapping; Artificial intelligence.

Venous thromboembolism in patients with isolated moderate to severe traumatic brain injury

Background. Traumatic brain injury (TBI) remains a big problem of modern neurosurgery, accompanied by high rates of disability and lethality. Venous thromboembolism (VTE) including venous thrombosis and pulmonary embolism (PE) plays a significant role in the structure of mortality in this pathology. Regimens and schemes of pharmacological prevention of VTE in TBI as well as corresponding preventative measures are not yet determined completely.Aim. To identify the frequency of VTE in patients with isolated moderate and severe TBI, and to evaluate the results of prevention and treatment of these complications in patients of this category.Materials and methods. Over a 3‑year period (from 2020 to 2023) 73 patients with isolated moderate and severe TBI (51 men and 22 women, mean age 61.0 ± 13.0 years) were treated in the V. M. Buyanov City Clinical Hospital. Of these, 31 patients received only conservative therapy, and 42 patients underwent surgery (craniotomy with hematoma removal, closed external hematoma drainage, and installation of intracranial pressure sensor). Ultrasound examination of the lower limb veins was performed at patient admission, then every 7 days until discharge from the hospital. Pharmacological prevention of VTE using low molecular weight heparin in non‑surgical patients was started after 1–2 days if computed tomography of the brain 24 h after admission showed no negative hematoma dynamics. Surgical patients were prescribed preventive medications 24 h after surgery if computed tomography confirmed intracranial hemostasis.Results. Venous thrombosis was detected in 22 (30.1 %) of 73 patients. PE complicated the underlying disease in 1 (1.4 %) case and was non‑fatal. There was no fatal PE in the study group. An increase of the initial intracranial hematoma volume occurred in 3 (4.1 %) patients, in 2 (2.8 %) patients the recurrence of hemorrhage occurred before the beginning of heparin administration, and in 1 (1.4 %) case against the background of therapeutic doses of anticoagulants prescribed for venous thrombosis. In the majority of cases (82.0 %; 18 of 22 patients) thromboses were localized in deep veins of the lower leg and were asymptomatic. Intrahospital mortality was 23.3 % (17 patients), all lethal outcomes were due to the course of traumatic brain disease.Conclusion. VTE is a frequent complication of TBI with intracranial hemorrhage. Regular ultrasound diagnostics makes it possible to diagnose asymptomatic distal venous thrombosis in a timely manner and to prescribe therapeutic doses of low molecular weight heparin in time which in turn allows to avoid fatal PE. Currently, there are no clear domestic recommendations for the prevention and, most importantly, for the treatment of these complications in patients with isolated moderate and severe TBI, which requires further active study of this problem.

Brain Fluid Clearance After Traumatic Brain Injury Measured Using Dynamic Positron Emission Tomography.

Brain fluid clearance by pathways including the recently described paravascular glymphatic system is a critical homeostatic mechanism by which metabolic products, toxins, and other wastes are removed from the brain. Brain fluid clearance may be especially important after traumatic brain injury (TBI), when blood, neuronal debris, inflammatory cells, and other substances can be released and/or deposited. Using a non-invasive dynamic positron emission tomography (PET) method that models the rate at which an intravenously injected radiolabeled molecule (in this case 11C-flumazenil) is cleared from ventricular cerebrospinal fluid (CSF), we estimated the overall efficiency of brain fluid clearance in humans who had experienced complicated-mild or moderate TBI 3-6 months before neuroimaging (n = 7) as compared to healthy controls (n = 9). While there was no significant difference in ventricular clearance between TBI subjects and controls, there was a significant group difference in dependence of ventricular clearance upon tracer delivery/blood flow to the ventricles. Specifically, in controls, ventricular clearance was highly, linearly dependent upon blood flow to the ventricle, but this relation was disrupted in TBI subjects. When accounting for blood flow and group-specific alterations in blood flow, ventricular clearance was slightly (non-significantly) increased in TBI subjects as compared to controls. Current results contrast with past studies showing reduced glymphatic function after TBI and are consistent with possible differential effects of TBI on glymphatic versus non-glymphatic clearance mechanisms. Further study using multi-modal methods capable of assessing and disentangling blood flow and different aspects of fluid clearance is needed to clarify clearance alterations after TBI.

273 A Direct Domparative Analysis of Pediatric Traumatic Brain Injury Presentation and Outcomes in the United States and Uganda

INTRODUCTION: Pediatric traumatic brain injury (pTBI) is the leading cause of death and disability among children globally. However, few studies have explored pTBI in low- and middle-income countries (LMICs) compared to high-income countries (HICs). METHODS: Patient records were extracted from the Duke University Hospital subset of the National Trauma Data Bank (NTDB, n = 866) and a dataset at the Mbarara Regional Referral Hospital in Uganda (MRRH, n = 571). Descriptive statistics were performed to compare across settings. Logistic regression was used to quantify the odds of mortality in each setting given ICU utilization, admission GCS, and other factors. RESULTS: In-hospital mortality was higher in the LMIC versus the HIC (9.4% vs 2.9%, p &lt; 0.001), while ICU utilization was lower in the LMIC (9.0% vs 33.4%, p &lt; 0.001). Rates of surgical management did not differ significantly (15.8% vs 17.0%). More patients presented with moderate (27.8% vs 4.3%) and severe TBI (16.5% vs 11.8%) in the LMIC (p &lt; 0.001). No deaths were reported among patients presenting with moderate or mild TBI in the HIC setting, whereas LMIC pTBI patients died in every TBI severity category. Over 50% of LMIC ICU patients died, versus 8.1% of HIC ICU patients. In a multivariate regression model of mortality, ICU placement was associated with mortality (OR: 6.7, 95% CI: 2.1-20.9), an association not seen in the HIC setting. CONCLUSIONS: Pediatric TBI mortality is greater in the LMIC vs the HIC setting. The LMIC setting also had a high prevalence of moderate/severe TBI and low ICU availability and effectiveness. Future work should involve the implementation and evaluation of interventions to assess these gaps in the LMIC setting.

120 Outcome Related Thresholds of Near Infrared Spectroscopy Based Cerebrovascular Reactivity Metrics in Moderate Severe TBI: A Canadian High Resolution-TBI (CAHR-TBI) Cohort Study

INTRODUCTION: Dysfunctional cerebrovascular reactivity (CVR)/autoregulation contributes to secondary injury following traumatic brain injury (TBI). Currently, monitoring of CVR relies on intracranial pressure (ICP) monitoring and has known thresholds at which outcomes worsen. Interest has shifted to less invasive near infrared spectroscopic (NIRS) regional cerebral oxygen saturation (rSO2) based measures of CVR. However, threshold levels at which outcomes worsen have not yet been determined for these indices. METHODS: A retrospective multi-institutional cohort study utilizing the CAnadian High Resolution TBI (CAHR-TBI) Research Collaborative database was performed. The cohort included TBI patients with ICP, arterial blood pressure (ABP), and rSO2 monitoring treated in adult intensive care units (ICU). COx (using rSO2 and cerebral perfusion pressure) as well as COx_a (using rSO2 and ABP) were calculated for each subject as the rSO2 based indices of CVR. 2 x 2 tables were created grouping patients by alive/dead and favorable/unfavorable outcomes at various thresholds of COx and COx_a as well as rSO2 itself. Chi-square values were calculated and the threshold producing the highest value was identified as providing the best discriminative value. RESULTS: A total of 129 patients were included. For both COx and COx_a an optimal threshold value of 0.2 was identified for both survival (χ2 = 9.57, p = 0.0020; χ2 = 13.04, p = 0.0003 respectively) and favorable outcomes (χ2 = 5.98, p = 0.0145; χ2 = 8.94, p = 0.0028 respectively) with values above this associated with worse outcomes. Notably, there was no identifiable threshold for raw rSO2 values at which outcomes were identified to worsen. CONCLUSIONS: In this multi-institutional cohort study, COx and COx_a were found to have a uniform threshold of 0.2, above which clinical outcomes worsened. This study lays the groundwork to transition to less invasive means of continuously measuring CVR.

440 Retrospective Assessment of the Clinical Timeline and Predictors for Vasospasm Severity in Traumatic Brain Injury Within a Safety-Net Hospital Population

INTRODUCTION: Unlike aneurysmal subarachnoid hemorrhage, vasospasm following traumatic brain injury (TBI) is poorly understood and no guidelines-based recommendations for surveillance exist. METHODS: TBI patients admitted to the surgical ICU 11/2014-12/2020 with 2+ instances of TCD-diagnosed vasospasm were included. Clinical timelines, TBI severity by Glasgow Coma Score (GCS) (mild = 13-15, moderate = 9-12, severe = 3-8), presence of subarachnoid hemorrhage (tSAH), and vasospasm severity (mild, moderate, or severe) were extracted from records. One-way ANOVA analysis compared the highest severity of vasospasm noted with date of onset and total days of vasospasm. Significant differences in means were further analyzed with Games-Howell post-hoc test. Stata® determined the dependence of vasospasm severity upon imaging findings or the GCS via Chi2 analysis. RESULTS: Forty-four patients were identified (31 male, 13 female, median age 40 (15-92) years). Amongst mild TBIs (13), vasospasm was mild (9), moderate (1), and severe (3). For moderate TBIs (2), vasospasm was mild (1), moderate (0), and severe (1). For severe TBIs (29), vasospasm was mild (16), moderate (6), and severe (7). Thirty-two patients had tSAH, 19 with mild, 6 moderate, and 7 with severe vasospasm. Of the 12 patients without tSAH, 7 had mild, 1 moderate, and 4 with severe vasospasm. Median time to onset did not differ between mild (Hospital Day (HD) 3), moderate (HD 4), and severe (HD 3) vasospasm (p = 0.47). Mean duration of mild vasospasm (2.35 days) differed from severe vasospasm (6.73 days), (p &lt; 0.05). Neither presence of tSAH nor severity of TBI was related to severity of vasospasm (p = 0.11 and p = 0.61). CONCLUSIONS: Our study found that post-traumatic vasospasm can impact TBI patients, early, regardless of TBI severity or the presence of tSAH, suggesting early and routine surveillance for PTV may be warranted in all critically ill TBI patients.

Utilizing ultra-early continuous physiologic data to develop automated measures of clinical severity in a traumatic brain injury population

Determination of prognosis in the triage process after traumatic brain injury (TBI) is difficult to achieve. Current severity measures like the Trauma and injury severity score (TRISS) and revised trauma score (RTS) rely on additional information from the Glasgow Coma Scale (GCS) and the Injury Severity Score (ISS) which may be inaccurate or delayed, limiting their usefulness in the rapid triage setting. We hypothesized that machine learning based estimations of GCS and ISS obtained through modeling of continuous vital sign features could be used to rapidly derive an automated RTS and TRISS. We derived variables from electrocardiograms (ECG), photoplethysmography (PPG), and blood pressure using continuous data obtained in the first 15 min of admission to build machine learning models of GCS and ISS (ML-GCS and ML-ISS). We compared the TRISS and RTS using ML-ISS and ML-GCS and its value using the actual ISS and GCS in predicting in-hospital mortality. Models were tested in TBI with systemic injury (head abbreviated injury scale (AIS) ≥ 1), and isolated TBI (head AIS ≥ 1 and other AIS ≤ 1). The area under the receiver operating characteristic curve (AUROC) was used to evaluate model performance. A total of 21,077 cases (2009–2015) were in the training set. 6057 cases from 2016 to 2017 were used for testing, with 472 (7.8%) severe TBI (GCS 3–8), 223 (3.7%) moderate TBI (GCS 9–12), and 5913 (88.5%) mild TBI (GCS 13–15). In the TBI with systemic injury group, ML-TRISS had similar AUROC (0.963) to TRISS (0.965) in predicting mortality. ML-RTS had AUROC (0.823) and RTS had AUROC 0.928. In the isolated TBI group, ML-TRISS had AUROC 0.977, and TRISS had AUROC 0.983. ML-RTS had AUROC 0.790 and RTS had AUROC 0.957. Estimation of ISS and GCS from machine learning based modeling of vital sign features can be utilized to provide accurate assessments of the RTS and TRISS in a population of TBI patients. Automation of these scores could be utilized to enhance triage and resource allocation during the ultra-early phase of resuscitation.

Moderate Traumatic Brain Injury in Adult Population: The Latin American Brain Injury Consortium Consensus for Definition and Categorization.

Moderate traumatic brain injury (TBI) is a diagnosis that describes diverse patients with heterogeneity of primary injuries. Defined by a Glasgow Coma Scale between 9 and 12, this category includes patients who may neurologically worsen and require increasing intensive care resources and/or emergency neurosurgery. Despite the unique characteristics of these patients, there have not been specific guidelines published before this effort to support decision-making in these patients. A Delphi consensus group from the Latin American Brain Injury Consortium was established to generate recommendations related to the definition and categorization of moderate TBI. Before an in-person meeting, a systematic review of the literature was performed identifying evidence relevant to planned topics. Blinded voting assessed support for each recommendation. A priori the threshold for consensus was set at 80% agreement. Nine PICOT questions were generated by the panel, including definition, categorization, grouping, and diagnosis of moderate TBI. Here, we report the results of our work including relevant consensus statements and discussion for each question. Moderate TBI is an entity for which there is little published evidence available supporting definition, diagnosis, and management. Recommendations based on experts' opinion were informed by available evidence and aim to refine the definition and categorization of moderate TBI. Further studies evaluating the impact of these recommendations will be required.

Prevalence of fatigue and cognitive impairment after traumatic brain injury.

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. 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. 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. 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.

Disparities between Native Americans and Whites in trajectories of functional independence and life satisfaction over the 5 years after traumatic brain injury.

Traumatic brain injury (TBI) can lead to impairments in motor and cognitive function and reduced life satisfaction. TBI is one of the leading causes of death and disability worldwide and disproportionately affects Native Americans, who have the highest rates of TBI among all races in the United States and elevated likelihood for fatality and severe complications. This study investigated whether disparities in functional and life satisfaction outcomes exist longitudinally over the 5 years after complicated mild, moderate, or severe TBI between Native Americans and White individuals; it further explored which demographic and injury-related covariates account for them. The current study used a subsample of the national TBI Model Systems Database of 80 demographically and injury-severity matched Native American and White pairs (total n = 160). A series of longitudinal hierarchical linear models found that Native Americans experienced significantly lower Functional Independence Measure Cognitive and Motor trajectories than Whites; however, life satisfaction was comparable. Native Americans had declining cognitive function over time relative to a slight increase in White individuals. This differential movement dissipated with the addition of employment status at the time of injury and type of health insurance. These results demonstrate a profound need to further investigate the cultural and contextual variables unique to Native Americans that underlie these differences and highlight the importance of culturally responsive treatment and rehabilitation in bridging the gap in recovery. (PsycInfo Database Record (c) 2024 APA, all rights reserved).