Journal of neurotrauma最新文献

It is well-known that older adults have poorer recovery following traumatic brain injury (TBI) relative to younger adults with similar injury severity. However, most older adults do recover well from TBI. Identifying those at increased risk of poor recovery could inform appropriate management pathways, facilitate discussions about palliative care or unmet needs, and permit targeted intervention to optimize quality of life or recovery. We sought to explore heterogeneity in recovery from TBI among older adults as measured by home time per month, a patient-centered metric defined as time spent at home and not in a hospital, urgent care, or other facility. Using data obtained from Medicare administrative claims data for years 2010-2018, group-based trajectory modeling was employed to identify unique trajectories of recovery among a sample of United States adults age 65 and older who were hospitalized with TBI. We next determined which patient-level characteristics discriminated poor from favorable recovery using logistic regression. Among 20,350 beneficiaries, four unique trajectories were identified: poor recovery (n = 1929; 9.5%), improving recovery (n = 2,793; 13.7%), good recovery (n = 13,512; 66.4%), and declining recovery (n = 2116; 10.4%). The strongest predictors of membership in the poor relative to the good recovery trajectory group were diagnosis of Alzheimer's disease and related dementias (ADRD; odd ratio [OR] 2.42; 95% confidence interval [CI] 2.16, 2.72) and dual eligibility for Medicaid, a proxy for economic vulnerability (OR 5.13; 95% CI 4.59, 5.74). TBI severity was not associated with recovery trajectories. In conclusion, this study identified four unique trajectories of recovery over one year following TBI among older adults. Two-thirds of older adults hospitalized with TBI returned to the community and stayed there. Recovery of monthly home time was complete for most by 3 months post injury. An important sub-group comprising 10% of patients who did not return home was characterized primarily by eligibility for Medicaid and diagnosis of ADRD. Future studies should seek to further characterize and investigate identified recovery groups to inform management and development of interventions to improve recovery.

Our recent improved understanding of traumatic brain injury (TBI) comes largely from cohort studies of TBI patients with indication for computed tomography (CT). Using CT head as an inclusion criterion may overestimate poor outcomes after TBI with Glasgow Coma Scale (GCS) 13-15. We aimed to compare outcomes after TBI in adults who had a head CT scan (with negative findings) versus those who had no CT when presenting to an emergency department. This was a secondary analysis of a trial that recruited adults with GCS = 13-15 after TBI in Vancouver, Canada. We included 493 participants (18-69 years, 54% female), after removing n = 19 with traumatic abnormalities on CT (intracranial and/or skull fracture). Outcomes were Glasgow Outcome Scale Extended (GOSE), Rivermead Post-Concussion Symptoms Questionnaire (RPQ), Patient Health Questionnaire (PHQ)-9, and generalized anxiety disorder (GAD)-7 at 6 months post-injury. Over half (55%) of participants received a CT. At 6 months, 55% of participants with CT and 49% without CT had functional limitations on GOSE; 32% with CT and 33% without CT reported severe post-concussion symptoms (RPQ ≥16); 26% (with CT) and 28% (without CT) screened positive for depression (PHQ-9 ≥ 10), and 25% (with CT) and 28% (without CT) screened positive for anxiety (GAD-7 ≥ 8). In regression adjusted for personal variables, participants with CT had somewhat higher odds of worse functioning (ordinal GOSE; 1.4, 95% CI 1.0-2.0) but similar odds of severe post-concussion symptoms (1.1, 95% CI: 0.7-1.7), and depression (1.1, 95% CI: 0.7-1.7) and anxiety (1.0, 95% CI: 0.6-1.5) symptoms. Adults with and without head CT have mostly comparable outcomes from TBI with GCS = 13-15. Requiring CT by clinical indication for study entry may not create problematic selection bias for outcome research.

The prevalence of mild traumatic brain injury (mTBI) is high compared with moderate and severe TBI, comprising almost 80% of all brain injuries. mTBI activates a complex cascade of biochemical, molecular, structural, and pathological changes that can result in neurological and cognitive impairments. These impairments can manifest even in the absence of overt brain damage. Given the complexity of changes triggered by mTBI, a combination of drugs that target multiple TBI-activated cascades may be required to improve mTBI outcomes. It has been previously demonstrated that cotreatment with the U.S. Food and Drug Administration (FDA)-approved drugs lithium plus valproate (Li + VPA) for 3 weeks after a moderate-to-severe controlled cortical impact injury reduced cortical tissue loss and improved motor function. Since both lithium and valproate can exhibit toxicity at high doses, it would be beneficial to determine if this combination treatment is effective when administered at low doses and for a shorter duration, and if it can improve cognitive function, after a mild diffuse TBI. In the present study, we tested if the combination of low doses of lithium (1 mEq/kg or 0.5 mEq/kg) plus valproate (20 mg/kg) administered for 3 days after a mild fluid percussion injury can improve hippocampal-dependent learning and memory. Our data show that the combination of low-dose Li + VPA improved spatial learning and memory, effects not seen when either drug was administered alone. In addition, postinjury Li + VPA treatment improved recognition memory and sociability and reduced fear generalization. Postinjury Li + VPA also reduced the number of anti-ionized calcium binding adaptor molecule 1 (Iba1)-positive microglia counted using a convolutional neural network, indicating a reduction in neuroinflammation. These findings indicate that low-dose Li + VPA administered acutely after mTBI may have translational utility to reduce pathology and improve cognitive function.

Magnetic resonance imaging (MRI) remains the gold standard for evaluating spinal cord tissue damage after spinal cord injury (SCI). Several MRI findings may have some prognostic potential, but their evolution over time, especially from the subacute to the chronic phase has not been studied extensively. We performed a prospective observational longitudinal study exploring the evolution of MRI parameters from the subacute to chronic phase after human traumatic cervical SCI. The study, conducted between 2016 and 2021, involved standardized neurological examinations and MRI scans 1 month, 3 months, and 1 year after SCI. The study cohort comprises 52 patients with cervical SCI. Patients were classified into AIS grades (American Spinal Injury Association Impairment Scale), and neurological recovery was assessed using the Integrated Neurological Change Score. The MRI protocol included various routine sequences, allowing the evaluation of established parameters such as intramedullary hemorrhage, lesion dimensions, maximum spinal cord compression, and various grading scales. The persistence of intramedullary hemorrhage one month after injury was associated with worse lower extremity motor scores and pinprick values after 3 months, and also in the chronic phase. In addition, dorsal column T2-weighted hyperintensities detected 3 months post-injury and in the chronic phase were related to lower pinprick sensory scores. The basic score and Sagittal Grade at 1 month were predictive for motor function 3 months after SCI and for neurological recovery between 1 and 3 months after injury. The study contributes valuable insights into the utility of routine MRI sequences for evaluating traumatic cervical SCI during the subacute to chronic phase. The identified MRI parameters and scores offer prognostic information and could support clinical decision-making.

Motorized cycling (MC) is utilized as an alternative to traditional exercise in individuals who are unable to perform voluntary movements post-spinal cord injury. Although rodent models of MC often show more positive outcomes when compared with clinical studies, the cause of this difference is unknown. We postulate that biomechanical differences between rats and humans may contribute to this discrepancy. To begin to test this theory, we examined pedal reaction forces and electromyography (EMG) of hindlimb muscles as a function of cycle phase and cadence in a rat model of MC. We found that higher cadences (≥30 RPM) increased EMG and force, with higher forces observed in animals with contusion injuries as compared with transections. To further investigate the forces, we developed a technique to separate rhythmic (developed with the motion of the pedals) from nonrhythmic forces. Rhythmic forces resulted from induced eccentric muscle contractions that increased (amplitude and prevalence) at higher cadences, whereas nonrhythmic forces showed the opposite pattern. Our results suggest that muscle activity during MC in rats depends on the stretch reflex, which, in turn, depends on the rate of muscle lengthening that is modulated by cadence. Additionally, we provide a framework for understanding MC that may help translate results from rat models to clinical use in the future.

It is well documented that service members are exposed to repeated low-level blast overpressure during training with heavy weapons such as artillery, mortars and explosive breaching. Often, acute symptoms associated with these exposures are transient but cumulative effect of low-level repeated blast exposures (RBEs) can include persistent deficits in cognitive and behavioral health. Thus far, reliable diagnostic biomarkers which can guide countermeasure strategies have not been identified. In this study, rats were exposed to multiple field-relevant blast waves with 8.5 and 10 psi peak positive overpressures, applying one exposure per day for 14 consecutive days. micro-RNAs that can potentially be used as biomarkers for RBEs were assessed in blood, brain, and cerebrospinal fluid (CSF). RBE caused a differential pattern of changes in various miRNAs in blood, brain and CSF in an overpressure-dependent manner. Our key outcomes were decrease of mir-6215 and let-7 family miRNAs and increase of mir-6321 and mir-222-5p in brain, blood, and CSF. Expression pattern of these miRNAs is in concurrence with various neurological conditions such as upregulation of mir-6321 in focal ischemic injury and downregulation of mir-6215 in nerve injury model. Contrarily, Let-7 family miRNAs have neuroprotective role and their downregulation suggests progression of blast induced traumatic brain injury (bTBI) with RBE at 14× -8.5 psi. Repeated blast caused alterations in miRNAs that are likely involved in vascular integrity, inflammation, and cell death. These results indicate that miRNAs are differentially dysregulated in response to blast injuries and may represent better prognostic and diagnostic biomarkers than traditional molecules to identify blast-specific brain injury.

Spinal cord injury (SCI) results in intramedullary microvasculature disruption and blood perfusion deficit at and remote from the injury site. However, the relationship between remote vascular impairment and functional recovery remains understudied. We characterized perfusion impairment in vivo, rostral to the injury, using magnetic resonance imaging (MRI), and investigated its association with lesion extent and impairment following SCI. Twenty-one patients with chronic cervical SCI and 39 healthy controls (HC) underwent a high-resolution MRI protocol, including intravoxel incoherent motion (IVIM) and T2*-weighted MRI covering C1-C3 cervical levels, as well as T2-weighted MRI to determine lesion volumes. IVIM matrices (i.e., blood volume fraction, velocity, flow indices, and diffusion) and cord structural characteristics were calculated to assess perfusion changes and cervical cord atrophy, respectively. Patients with SCI additionally underwent a standard clinical examination protocol to assess functional impairment. Correlation analysis was used to investigate associations between IVIM parameters with lesion volume and sensorimotor dysfunction. Cervical cord white and gray matter were atrophied (27.60% and 21.10%, p < 0.0001, respectively) above the cervical cord injury, accompanied by a lower blood volume fraction (-22.05%, p < 0.001) and a higher blood velocity-related index (+38.72%, p < 0.0001) in patients with SCI compared with HC. Crucially, gray matter remote perfusion deficit correlated with larger lesion volumes and clinical impairment. This study shows clinically eloquent perfusion deficit rostral to a SCI, its magnitude driven by injury severity. These findings indicate trauma-induced widespread microvascular alterations beyond the injury site. Perfusion MRI matrices in the spinal cord hold promise as biomarkers for monitoring treatment effects and dynamic changes in microvasculature integrity following SCI.

The purpose of this study was to assess the performance of predictive blood biomarkers for responsiveness to targeted treatments for chronic psychological issues years after traumatic brain injury (TBI). Targeted Evaluation Action and Monitoring of TBI was a prospective 6-month interventional trial of participants with chronic TBI sequelae (n = 95). Plasma biomarkers were analyzed pre-intervention: glial fibrillary acidic protein (GFAP), tau, hyperphosphorylated tau Thr231 (p-Tau), von Willebrand factor (vWF), brain lipid-binding protein (BLBP), ubiquitin C-terminal hydrolase-L1 (UCH-L1), vascular endothelial growth factor-a (VEGFa), and claudin-5 (CLDN5). Clinical outcomes included the Post-Traumatic Stress Disorder (PTSD) Checklist for DSM-5 (PCL-5) and Brief Symptom Inventory-18 (BSI-18). Regression models were built for change in PCL5/BSI-18. Biomarkers and covariates were included. Two models were built to identify responders (improved beyond the minimum clinically important difference). The model to predict change in PCL5 (R²=0.64; p < 0.001) included vWF (p = 0.032), BLBP (p = 0.001), tau (p = 0.002), VEGFa (p = 0.015), female sex (p = 0.06), and military status (p = 0.014). The model to predict change in BSI-18 (R²=0.42; p = 0.003) included vWF (p = 0.042), VEGFa (p = 0.09), BLBP (p = 0.01), CLDN5 (p < 0.001), female sex (p = 0.012), and military status (p = 0.004) as predictors. The model to differentiate participants who improved for PCL5 (R²=0.68; p < 0.001; AUC = 0.93) included vWF (p = 0.02), VEGFa (p = 0.008), and BLBP (p = 0.006). The model to differentiate participants who improved for BSI-18 (R²=0.25; p = 0.04; AUC = 0.75) included UCH-L1 (p = 0.03), GFAP (p = 0.06), and vWF (p = 0.03). Combinations of pre-intervention blood biomarkers were able to differentiate responders from nonresponders in both post-traumatic stress and overall psychological health domains.

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Randomized controlled trials (RCTs) are the cornerstone to evaluate the efficacy of an intervention. To assess the methodology of clinical research, we performed a systematic review that evaluated the different outcomes used in RCTs targeting the early phase of moderate-to-severe adult TBI from 1983 to October 31, 2023. We extracted each outcome and organized them according to the COMET and OMERACT framework (core area, broad domains, target domains, and finally outcomes). A total of 190 RCTs were included, including 52,010 participants. A total of 557 outcomes were reported and classified between the following core areas: pathophysiological manifestations [169 RCTs (88.9%)], life impact [117 RCTs (61.6%)], death [94 RCTs (49.5%)], resource use [72 RCTs (37.9%)], and adverse events [41 RCTs (21.6%)]. We identified 29 broad domains and 89 target domains. Among target domains, physical functioning [111 (58.4%)], mortality [94 (49.5%)], intracranial pressure target domain [68 (35.8%)], and hemodynamics [53 (27.9%)] were the most frequent. Outcomes were mostly clinician-reported [177 (93.2%)], while patient-reported outcomes were rarely reported [11 (5.8%)]. In our review, there was significant heterogeneity in the choice of end-points in TBI clinical research. There is an urgent need for consensus and homogeneity to improve the quality of clinical research in this area.