Journal of Neurotrauma

Repetitive head impacts (RHI) from contact and collision sports have been associated with later-life cognitive and neurobehavioral impairments, as well as neurodegenerative conditions such as chronic traumatic encephalopathy (CTE). RHI-associated clinical sequelae among female former soccer players, specifically, are not well understood. This cross-sectional study aimed to examine the relationship of RHI exposure proxies (e.g., total years of soccer play, highest level of play, and estimated cumulative heading frequency) with clinical measures (e.g., subjective cognitive complaints, objective cognitive performance, behavioral dysregulations, and depressive symptoms) among 3,174 women, aged 40 years or above, enrolled in the Head Impact and Trauma Surveillance Study (HITSS), all of whom played organized soccer. HITSS participants completed an online battery that elicited self-reported cognitive and behavioral complaints and depressive symptoms, and that assessed cognitive performing via computerized tests. Multivariable linear and logistic regression models estimated associations between soccer-related RHI proxies and outcome measures, adjusting for age and education. Among the former soccer players, longer duration of soccer play, higher level of play, and greater estimated cumulative heading frequency were significantly associated with worse self-reported cognitive functioning, greater behavioral dysregulation, and elevated depressive symptom severity (range of significant unstandardized B coefficients: 0.02 to 0.52). Higher estimated cumulative heading exposure was associated with higher odds of clinically meaningful elevations on subjective measures (OR range: 1.05 to 1.13) There were no associations between any of the RHI proxies and performance on the objective computerized cognitive assessments. Among middle-aged women who played organized soccer, cumulative RHI exposure was associated with small but statistically significant effects for measures of subjective cognitive complaints, behavioral functioning, and depressive symptoms. We found no associations for objective outcomes of cognitive function. Continued monitoring of this large cohort of female former soccer players will improve understanding of long-term consequences of soccer play.

Background: Prognostication after moderate-to-severe traumatic brain injury (TBI) rarely captures long-term functional recovery, despite its importance to patients, families, and clinicians. Large trauma registries such as the Trauma Quality Improvement Program (TQIP) dataset contain detailed clinical data but lack systematic follow-up, limiting their ability to study longer-term functional outcomes. Methods: We developed and externally validated a machine learning model to predict favorable six-month functional outcome (GOS MD/GR or GOSE >=5) using harmonized data from two randomized clinical trials: CRASH (training) and ROC-TBI (validation). Five candidate classifiers (random forest [RF], linear discriminant analysis, k-nearest neighbors, naive Bayes, and support vector machine) were trained using seven shared clinical predictors. Models were evaluated using ROC-AUC, calibration metrics, and performance at the Youden optimal threshold and a high-sensitivity secondary threshold. The final model was applied to patients with moderate-to-severe TBI in the national TQIP registry (2017-2022) to estimate population-level recovery patterns. Results: The RF model demonstrated the highest overall performance after recalibration, achieving strong discrimination (AUC internal and external, 0.887 and 0.784), good calibration, and high sensitivity (0.890) and negative predictive value (0.909). Applied to 63,289 patients from TQIP, the model estimated that 45% would achieve favorable six-month outcomes at the Youden optimal threshold and 57% at the high-sensitivity threshold, with predicted recovery aligning with established clinical correlates such as younger age, higher admission GCS, and lower rates of penetrating or brainstem injuries. Conclusion: A machine learning model trained on high-quality trial data can generate clinically plausible estimates of long-term functional recovery when applied at scale to national trauma registries that lack systematic follow-up. This approach enables imputation of functional outcomes in datasets lacking follow-up, supports benchmarking and quality improvement across trauma systems, and provides a foundation for future models incorporating physiologic time-series, imaging, and biomarker data.

Traumatic brain injury (TBI), particularly sports- and recreational activity related mild TBI (mTBI), is common in young adults and can be followed by persistent attentional and executive complaints. This study investigated chronic ([≥]6 months post-injury) structural brain alterations in gray matter (GM) and white matter (WM) and their associations with self-reported inattentive and hyperactive/impulsive symptoms, with a focus on sex-differentiated patterns. Structural brain properties in gray matter (GM) and white matter (WM) were acquired from 44 subjects with TBI and 45 matched controls, by utilizing structural MRI and diffusion tensor imaging techniques. Behavioral measures assessing severities of post TBI inattentive and hyperactive/impulsive symptoms were collected from each participant. Between-group and sex-specific differences of these brain and behavioral measures were conducted. Interactions among the TBI-induced significant brain- and behavioral-alterations, and their sex-specific patterns, were assessed as well. Male-dominated pattern of increased cortical thickness in superior parietal lobule (SPL) and female-dominated pattern of higher superior longitudinal fasciculus and superior fronto-occipital fasciculus (sFOF) fractional anisotropy (FA) were observed in the TBI group, when compared to controls. In males with TBI, greater SPL cortical thickness was significantly correlated with increased inattentive behaviors. In females with TBI, higher FA of sFOF was significantly correlated with decreased hyperactive/impulsive behaviors. Findings suggest that TBI-induced superior parietal cortical GM abnormalities may significantly cause attention deficits in patients with TBI, especially in males; while optimal post-TBI WM recovery in sFOF significantly contributes to maintenance of inhibitive control in patients with TBI, especially in females.

Traumatic Brain Injury (TBI) patients may suffer from a number of long-term complications after injury such as impaired motor skills, cognitive decline, and sensory abnormalities including chronic pain. Disruption of endogenous pain modulatory pathways likely contributes to development of chronic pain in a wide range of conditions including TBI. Aerobic exercise has been shown to impact pain syndromes. Here we investigate the effect of exercise on pain outcome measures after TBI using a lateral fluid percussion (LFP) model and voluntary running wheels in male and female rats. We tested mechanical nociceptive reactivity with von Frey fibers and descending control of nociception (DCN) using hindpaw sensitization with PGE2 followed by a capsaicin-test stimulus to the forepaw. Pharmacological studies employed the administration of noradrenergic (NA) and serotoninergic receptor blockers. Neuropathological studies quantified neuroinflammatory changes and axonal damage. We found that exercise decreased the duration of the acute phase of pain from [~]5 weeks to 2-3 weeks in female and male TBI rats respectively, gains that could be reversed using the 1-adrenoceptor (1AR) antagonist, prazosin. Exercise also prevented the loss of DCN for at least 180 days post-injury in both male and female TBI rats. The intact DCN response in male and female TBI rats provided by exercise could be blocked using prazosin. Surprisingly, exercise-mediated restoration of the DCN response in male TBI rats was not blocked by the 5-HT7 receptor antagonist, SB-267790, the receptor system through which serotonin reuptake inhibitors restore DCN after TBI in male rats. Therefore, the transition from a noradrenergic to a serotonergic inhibitory pain pathway that we typically see in male TBI rats, was blocked by exercise. Assessment of neuropathology, acutely after TBI, reveals that both the astrocyte and microglial response to injury is significantly greater in male TBI compared to female TBI, regardless of exercise. The effect of exercise on the extent of neuroinflammation after injury was minimal in TBI rats of both sexes. In contrast, exercise significantly decreased the amount of axonal loss in the corpus callosum in both male and female TBI rats compared to sedentary TBI rats. However, the extent of axonal loss after TBI in both exercise and sedentary male rats was greater than in female exercise and sedentary groups respectively. These results demonstrate that exercise is a promising treatment for chronic pain after TBI in both male and females. It also highlights that dysfunction of the endogenous pain modulatory pathways observed in male rats after TBI can be prevented by exercise, possibly by reducing axonal loss.

Repeated exposure to hypoxia (oxygen levels below sea-level atmospheric conditions, [~]21%) alternated with regular voluntary exercise, known colloquially as Living High, Training Low, or simply High-Low, is used by elite athletes to boost exercise benefits and athletic performance. While paradigms of High-Low training have been utilized by Olympic athletes for decades, the therapeutic potential of a High-Low regimen in the context of neurotrauma has yet to be investigated. This long-term experiment evaluated the independent and combined effects of repeated hypoxic exposure and voluntary exercise on functional outcomes within the context of preclinical spinal cord injury (SCI). We hypothesized that combinatorial High-Low training enhances functional recovery, beyond either exercise or repeated exposures to hypoxia alone, to improve outcomes after SCI. Adult female rats (n=62) underwent a high-cervical hemisection (LC2H) to model spinal cord injury. At 6 weeks post-SCI, treatment (access to exercise wheel, repeated exposure to normobaric hypoxia at rest, or alternation of both) began in the surviving subjects (n=49). Despite initiation of treatment beyond the acute post-injury phase, High-Low therapy significantly improved respiratory function and prevented the development of SCI-associated anxiety-like behaviors. Notably, repeated in vivo exposure to normobaric hypoxia induced a shift in peripheral T cell profiles, characterized by increased CD4+ and reduced CD8+ expression. These findings indicate that combining repeated exposure to hypoxia with voluntary exercise as a therapy could promote recovery in the existing spinal cord-injured population. Collectively, this work provides a foundational first step for further investigation of High-Low training as a rehabilitation therapy for individuals living with SCI.

Spinal cord injury (SCI) can result in temporary or permanent alterations in sensory, motor, and autonomic functions as a result of primary mechanical damage to the spinal cord. Functional recovery is often limited due to persistent secondary injury mechanisms like inflammation, vascular breakdown, and cellular damage. Mitochondrial dysfunction is a key driver of secondary injury pathology, and while mitochondrial-targeted therapies have shown promise in rodent models of injury, functional improvements fail to translate to humans. Pigs are excellent models for understanding both the behavioral and molecular consequences of SCI because of their physiological similarity to humans, which could bridge the translational gap between rodent research and clinical implementation. To develop effective, mechanistic-based therapies, we must understand the molecular underpinnings of SCI using both male and female animal models with high translational fidelity at multiple time points after injury. To date, research on mitochondrial dysfunction following SCI has been limited to female rodent models measured acutely (6h-7d) after injury. Here, we studied mitochondrial dysfunction at three different time points in male pigs to establish a relative time course of mitochondrial impairment following SCI that may be therapeutically targeted to treat secondary complications of injury. We measured mitochondrial bioenergetic function and electron transport chain (ETC) complex activities, as well as qualified mitochondrial dynamics and oxidative damage acutely (2h), sub-acutely (24h), and chronically (9wk) after SCI in adult male pigs. The results show distinct patterns of mitochondrial dysfunction between time points with functional deficits occurring 2h post-SCI, increased mitochondrial fragmentation at 24h post-SCI, and mitochondrial recovery by 9wks post-SCI. These studies offer insight into mitochondrial changes across time in a clinically relevant animal model of SCI in hopes of bridging the translational research gap.

PurposePrevious research has demonstrated effects of head impact exposure on cortical neurophysiology, which may help with understanding variability in clinical sequelae. In separate lines of research, neurochemical and gene transcription markers of vulnerability to traumatic brain injury (TBI) have been established. The purpose of this study was to examine whether these cortical neurochemical and gene transcription gradients are spatially aligned with neurophysiological effects. Methods and MaterialsMagnetoencephalography (MEG) data was collected at a total of 278 pre- and post-season timepoints from 91 high school football players across up to four seasons of play. Of the 91 football players, 10 experienced a concussion, and of the remaining 81 non-concussed players, 71 met the criteria for complete imaging and kinematic data, with post-season evaluations less than six weeks after the end of the season. Head impacts were tracked over the course of the season with helmet-mounted sensors. MEG data underwent source-imaging, frequency-transformation, spectral parameterization, and linear modeling to examine the effects of concussive and non-concussive head impact exposure on pre-to-post-season changes in rhythmic and arrhythmic neurophysiological activity. To determine clinical effects, parent reported Post-Concussive Symptom Inventory scores related to cognitive symptoms were correlated with cortical neurophysiological changes. Multi-atlas data of neurochemical system densities from neuromaps and gene expression from the Allen Human Brain Atlas were examined for alignment with head impact-related alterations in neurophysiology via nonparametric spin-tests with autocorrelation-preserving null models (5,000 Hungarian spins; pFDR <.05). ResultsConcussion-related reductions in cortical excitability (i.e., aperiodic exponent slowing) were aligned with atlas-based norepinephrine transporter (NET) and alpha-4 beta-2 nicotinic receptor (4{beta}2) densities, and with apolipoprotein E (APOE) and brain-derived neurotrophic factor (BDNF) expression levels. More severe cognitive symptoms associated with concussion-related slowing of aperiodic neurophysiology were also aligned with atlas-based NET and 4{beta}2 receptor densities. Similar changes in cortical excitability related to non-concussive head impact exposure were colocalized with serotonin receptor (5-HT1A) density maps and APOE and BDNF expression. Rhythmic alpha activity was reduced by concussion and colocalized with histamine (H3) and mu-opioid (MOR) receptors, among others, as well as with gene transcription atlases of APOE and C-C chemokine receptor 5 (CCR5). ConclusionsThese findings extend our previous work to show that the effects of head impact exposure on neurophysiology are strongest in cortical areas with specific neurochemical and genetic profiles that are known to signal vulnerability to traumatic brain injury, and that these spatial alignments are also associated with self-reported symptom severity. Clinical Relevance / ApplicationChange in cortical excitability, as measured here by MEG, has potential value as a clinical tool for concussion diagnosis and prognosis. We provide genetic and neurochemical contextualization for these changes that may extend their clinical applications, for example to concussion risk assessment and pharmacotherapies.

Background: Spinal cord injury (SCI) is associated with widespread reorganisation of cortical sensorimotor circuits. Persistent complications such as spasticity and neuropathic pain suggest that homeostatic plasticity, which normally helps stabilise and constrain activity-dependent changes in sensorimotor circuits, may be disrupted after SCI. Homeostatic plasticity can be probed using repeated blocks of transcranial direct current stimulation (tDCS); in healthy individuals, two closely spaced excitatory blocks typically leads to an inhibitory response, reflected as a reduction in corticomotor excitability. Objective: To determine whether individuals with SCI show reduced homeostatic suppression of corticospinal excitability in response to repeated anodal tDCS, compared with healthy controls. Methods: Twenty adults with thoracic or below SCI and 20 healthy controls completed three counterbalanced sessions. Each session comprised two 10-minute blocks of 2 mA tDCS separated by 5 minutes, with the second block always being anodal tDCS over left primary motor cortex. The first block was either anodal, cathodal, or sham tDCS, yielding 3 condition types: anodal-anodal, cathodal-anodal, and sham-anodal. To assess corticomotor excitability, transcranial magnetic stimulation-evoked motor evoked potentials (MEPs) were elicited at baseline, after priming, and every 5 minutes for 60 minutes after the second block. The primary outcome was percent change in MEP amplitude from baseline. Results: In the anodal-anodal condition, the SCI group showed greater facilitation than controls over 0-30 minutes (estimate = 83.09, 95% CI 49.75 to 116.43, p < 0.001), suggestive of a weaker homeostatic response. The cathodal-anodal condition led to a significant overall facilitatory effect with no between-group difference, while the sham-anodal condition showed no change in MEP amplitude relative to baseline. Within the SCI group, exploratory subgroup analysis suggests that those with neuropathic pain and a traumatic injury showed greater facilitation in the anodal-anodal condition than those without these features, indicative of a weaker homeostatic response. Conclusions: SCI is associated with impairment in the homeostatic regulation of corticomotor excitability following repeated excitatory brain stimulation. Disrupted plasticity stabilisation may be relevant to persistent symptoms such as neuropathic pain.

BACKGROUNDThe recovery from sport-related concussion (SRC) is highly heterogenous, with many individuals experiencing symptoms that persist beyond typical recovery timeframes. The early identification of individuals at risk of prolonged symptoms is therefore critical to inform timely interventions and set realistic recovery expectations. Although acute symptom burden is one predictor of future symptom burden, reliance on self-reported measures may limit objectivity and reduce clinical utility in settings where symptom evaluation may be unreliable. In this prospective cohort study, we evaluated the discriminatory accuracy of the CogState Brief Battery, alone and in combination with the Sport Concussion Assessment Tool (SCAT), to classify Australian football players with SRC from Australian footballers without SRC at 24-hours post-injury/match. Furthermore, we examined whether CogState performance and symptom severity at 24 hours were associated with symptom outcomes at one-week post-injury. Adult amateur Australian football players (n=181) were recruited following SRC (n=109 SRC, 86% male) or after a non-injured match (n=72, 90% male). Participants completed the CogState Brief Battery, SCAT and Rivermead Post Concussion Questionnaire (RPQ) at 24-hours and one-week post-injury or match. Area under the receiver operating characteristic (AUC) analyses quantified the ability of 24-hour CogState task performance and SCAT symptom severity to distinguish SRC from controls. Linear regression models examined associations between CogState performance and symptom severity (SCAT and RPQ), within and across the 24-hour and one-week time points. Additional models evaluated whether combining 24-hour symptom severity assessments with CogState performance improved prediction of one-week symptom burden and symptomatic status. SCAT symptom severity demonstrated excellent discriminatory classification accuracy for SRC versus controls at 24-hours post-injury (AUC [95% CI]: 0.949 [0.916 - 0.981]). CogState task performance showed lower discriminatory accuracy but demonstrated fair classification and prognostic utility (e.g., Identification task AUC [95% CI]: 0.666 [0.582 - 0.750]). CogState performance at 24-hours was significantly associated with overall symptom severity at both 24-hours and one-week, as well as with symptom severity across individual symptom domains. In combined models, 24-hour symptom severity and CogState performance independently contributed to the prediction of symptomatic from asymptomatic individuals at one-week post-SRC (e.g., Identification task AUC [95% CI]: 0.721 [0.606 - 0.835] for classification based on <4 versus [&ge;]4 symptoms). These findings indicate that CogState performance at 24-hours post-SRC may serve as an objective adjunct to subjective symptom-based reporting, supporting both diagnosis and early prognostication in the clinical evaluation of SRC.

Preclinical traumatic brain injury (TBI) research relies on experimental models that vary by mechanism, parameters, surgical procedures, species, strains, and ages, to name a few. While these models are crucial for understanding injury mechanisms and testing therapies, the progress in translating this knowledge to the clinic has been limited. This is in part due to fragmented resources and inconsistent reporting of critical variables. Here, we introduce the PRECISE-TBI model catalog, a centralized, queryable resource that consolidates metadata from published studies. The catalog integrates curated annotations from more than 450 papers, including details such as age, sex, strain, model type, device, and injury parameters. Where available, entries are also linked to protocols and datasets to enhance transparency and reproducibility. The Model Catalog serves as a living resource that enables cross-study comparison, identifies gaps in reporting, and connects the literature to datasets, protocols, device information, and other relevant resources. Analysis of the initial catalog entries revealed gaps in the reporting of device, age, and weight. In contrast, the reporting of sex improved over time, with over 90% of recent studies within the catalog papers reporting sex. Strain was also reported in most studies, with consistent reporting of specificity, especially for the C57 mice substrain. We expect the Model Catalog to serve as a valuable tool to enhance study design and reproducibility in preclinical TBI research while advancing FAIR data principles in the TBI field.

Critically ill children admitted to pediatric intensive care units (PICUs) face significant neurological risks, but it remains unclear whether neurological assessments are adequately integrated into clinical routines. We aimed to evaluate the global scientific landscape regarding neurological examination in PICU, combining bibliometric analysis with clinical-guided critical analysis. A comprehensive search was conducted on the Web of Science Core Collection (WoS-CC) using terms related to pediatric critical care and neurological evaluation. Eligible publications were original research articles approaching neurological assessment during PICU stay. Bibliometric indicators, science mapping, and study design profiling were analyzed. In a separate, clinically guided interpretative layer, reporting patterns related to timing, tools, and strategies of neurological assessment were synthesized. From 359 records, 128 articles met inclusion criteria. The United States accounted for over half of the publications, while most studies employed retrospective designs and focused on traumatic brain injury or cardiac arrest. Despite the relevance of clinical neurological examination - especially using the Glasgow Coma Scale (GCS) and Pediatric Cerebral Performance Category (PCPC), advanced neuromonitoring tools, e.g., EEG, intracranial pressure monitoring, and biomarkers were inconsistently applied. Notably, neurological evaluations were often underreported at admission and discharge and rarely extended to non-neurological PICU conditions. Our findings reveal a critical gap between the neurological vulnerability of PICU patients, and the limited, inconsistent assessment strategies reported in the literature. Expanding structured neurological evaluation to all critically ill children, not only those with overt neurological diagnoses, seems essential to promote brain health and long-term recovery.

Persistent pain is a common but poorly understood outcome of traumatic burn injury. With increasing numbers of patients surviving their burn injuries, ongoing pain presents a growing complication to patient healing and quality of life. Despite more women reporting chronic pain post-burn than men, preclinical burn research rarely includes female animals. To address this gap, this study examined a diverse set of behavioral outcomes in male and female rats after a unilateral full-thickness burn to the hind paw. Utilizing traditional methods to assess evoked pain behaviors, new technology to assess gait abnormalities, and established techniques to evaluate comorbid anxiety-like behavior, we determined that male and female rats have divergent pain-related behaviors post-burn. Both sexes experienced mechanical allodynia after burn injury, but only males experienced thermal hyperalgesia. In contrast, female rats were acutely resistant to noxious thermal stimulation. While both sexes demonstrated gait abnormalities post-burn when freely ambulating, female rats exhibited a wider range of abnormal gait features, which were more severe and longer-lasting than those in males. However, despite both sexes demonstrating symptoms of persistent pain, only males displayed anxiety-like behavior on the Elevated Zero Maze. In conclusion, our study found that male and female Sprague Dawley rats displayed divergent, sex-specific evoked pain responses, gait dysfunction, and anxiety-like behavior after full-thickness burn injury. Future studies should examine the underlying mechanisms behind these behavioral sex differences. PerspectiveThis article takes a novel approach to pain behavior testing after full-thickness burn injury, capturing behaviors beyond traditional reflexive ("evoked") behaviors. The results of this article provide evidence that preclinical research must expand behavioral testing to capture the full animal pain experience and better model human patient outcomes.

Mild traumatic brain injuries (mTBI) can substantially impact quality of life, and repetitive mTBIs (rmTBI) can amplify injury effects compared to a single injury. However, effective clinical treatments remain elusive, largely due to an incomplete understanding of the underlying injury mechanisms. Neuroinflammation has emerged as a key contributor to worse functional outcomes after mTBI/rmTBI. While microglia are traditionally viewed as primary mediators of post-injury inflammation, accumulating evidence suggests neurons play an immunomodulatory role in initiating the rmTBI inflammatory cascade through activation of intracellular proinflammatory pathways like p38 MAPK and secretion of cytokines that, in turn, stimulate microglial activation. Here, we tested whether inducible neuronal p38 knockout protects against functional, immune, and cerebrovascular consequences of a weight-drop closed head injury model of rmTBI. A battery of functional assays was conducted 4 weeks post-injury, and tissues were collected at both 4 hours and 4 weeks following final CHI. In males, neuronal p38 knockout protected against injury-induced depressive-like behavior, hyperactivity, synaptic loss, microglial reactivity, cytokine upregulation, and reduction in cerebral blood flow. In females, neuronal p38 knockout protected against risk-taking behavior and partially protected against cytokine upregulation but had limited effect on microglial reactivity and cerebral blood flow. Together, these findings identify neuronal p38 as a sex-dependent driver of rmTBI-associated neurological consequences, and they support neuronal p38-immune signaling as a mechanistically relevant therapeutic target for future studies.

BackgroundSpinal cord injury (SCI) triggers persistent neuroinflammation, gliosis, neuronal loss, and demyelination, leading to motor deficits and neuropathic pain. Botulinum neurotoxin type A (BoNT/A) has shown anti-inflammatory and neuroprotective effects in acute SCI, but its potential in the chronic phase remains unclear. This study investigates whether combining BoNT/A with electrical muscle stimulation (EMS) enhances recovery in chronic SCI. MethodsAdult mice with severe thoracic SCI (paraplegic) underwent EMS (30 min/day for 10 non-consecutive days starting 3 days post-injury) or no stimulation. Fifteen days after SCI, animals received a single intrathecal injection of BoNT/A (15 pg/5 L) or saline. Functional recovery was assessed up to 60 days as well as in moderate and mild SCI mice, neuropathic pain onset and maintenance were evaluated. Spinal cord tissue was analysed for astrocytic and microglial morphology, neuronal and oligodendroglia survival, myelin protein expression, and in vitro effects on oligodendrocyte precursor cells (OPCs). The phenotype of hindlimb muscles was evaluated through morphological and gene expression analyses. ResultsEMS was able to counteract muscle atrophy and fibrosis, and when combined with BoNT/A, also denervation. Moreover, the combination restored hindlimb motor function in chronic SCI, whereas BoNT/A or EMS alone were ineffective. Neuropathic pain, a common comorbidity associated with SCI, was mitigated by BoNT/A treatment even when administered in the chronic phase. BoNT/A reduced astrocytic hypertrophy and excitatory synapse association and was associated with a morphology-based redistribution of microglial profiles toward a resting-like classification, decreased apoptosis, and increased neuronal and oligodendroglia survival. Myelin basic protein expression was significantly elevated in vivo. In vitro, BoNT/A promoted OPC differentiation into myelinating oligodendrocytes, increased process complexity, and upregulated Myelin basic protein, galactocerebroside C, proteolipid protein, and myelin oligodendrocyte glycoprotein under both proliferative and differentiating conditions. Cleaved SNAP25 colocalization with OPC confirmed direct BoNT/A internalization and activity. ConclusionsBoNT/A exerts multi-cellular neuroprotective actions in chronic SCI, supporting neuronal and oligodendroglia survival, reducing neuroinflammation, enhancing remyelination and the combination with EMS promotes substantial recovery of muscle homeostasis within a permissive microenvironment shaped by early stimulation. Its efficacy depends on a permissive microenvironment achieved through EMS. These results provide strong rationale for the clinical evaluation of BoNT/A as a therapeutic strategy for chronic SCI.

Accumulating evidence supports sex differences in traumatic brain injury (TBI) outcomes, however the underlying processes that lead to sex differences are not well understood. TBI results in the initiation of molecular and cellular responses that facilitate the progression of neurodegeneration. Importantly, little is known about how the circulating hormone profile is altered in response to TBI, and whether sex differences in endocrine responses might shape secondary injury pathologies. Using intact male and female mice in a preclinical TBI model, we assessed changes in plasma hormone concentrations and cortical gene expression at 24 and 72 hours after TBI. We demonstrate that males and females exhibit sex-specific alterations in circulating levels of progesterone, testosterone, androstenedione, estradiol and dehydroepiandrosterone (DHEA) in response to TBI. We also identified sex differences in the expression of genes that are involved in immune responses and tissue remodeling after injury. Moreover, we report divergent circulating hormone and gene expression correlations between sexes.

Background: Acute treatments for patients with spinal cord strokes (SCS), including lumbar drain, blood pressure augmentation, corticosteroids, antiplatelets, and anticoagulants, are largely extrapolated from literature on cerebral infarcts or based on suspected SCS physiology. This study adds to the knowledge of symptomatology and management of SCS. Methods: This retrospective cohort study included patients from one medical system from 2000-2025. Multivariate ordinal logistic regressions were performed to evaluate associations of SCS treatments with the primary outcome of ambulatory status (independently ambulatory, ambulatory with assistance, non-ambulatory) at first follow-up, as well as secondary outcomes of modified Rankin Scale (mRS) and modified Japanese Orthopedic Association (mJOA) scores. SCS severity by American Spinal Injury Association impairment scale (AIS) with grade A as the comparator, age, sex, and whether SCS was spontaneous/periprocedural were covariates. Odds ratios (OR) greater than 1 were associated with better ambulatory status, lower mRS, and higher mJOA. Results: 130 SCS patients were included. Median age at SCS onset was 62 years, 42% were female, and 39% were periprocedural. Median first follow-up was 57 days. AIS grade was A for 28%, B for 25%, C for 28%, and D for 26%. SCS severity had significant associations with outcomes. For ambulatory status, AIS B OR 2.78, 95% CI 1.03-7.69, p-value 0.045; AIS C OR 16.7, 95% CI 5.56-50.0, p-value <0.01; AIS D OR 125, 95% CI 33.3-500, p-value <0.01. Corticosteroids were associated with improved ambulatory status and mJOA at follow-up (OR 2.38, 95% CI 1.15-5, p-value 0.023 and OR 2.27, 95% CI 1.09-4.76, p-value 0.030, respectively). No treatment had a significant association with mRS. Conclusion: Initial SCS severity had the strongest association with outcomes. Corticosteroids were associated with a better ambulatory status and mJOA. This study can help guide clinician management of patients with SCS.

Introduction: Adults with spinal cord injury (SCI) often experience reduced or lost sensation and movement, impairing the ability of the brain to locate paralyzed body parts, which, in turn, compromises sensorimotor recovery. This disruption of the internal body map of the brain, or mental body representations (MBR), also contributes to neuropathic pain in about 69% of adults with SCI. Medications for neuropathic pain are often ineffective and can cause adverse reactions. Our previous pilot clinical trial showed that Cognitive Multisensory Rehabilitation (CMR), a physical therapy that restores MBR, produced significant, lasting reductions in neuropathic pain, improved sensorimotor function, and enhanced brain function. Building on these results, we examined whether 8 weeks of CMR or adaptive fitness (1) improved sensorimotor function and reduced pain; (2) greater brain activity and connectivity related to sensorimotor function and MBR in adults with SCI. Methods: Sixteen participants (52+/-8 years old, 13+/-10 years post-SCI) were randomized to 8 weeks of CMR or adaptive fitness (45 min, 3x/week). Ten participants had neuropathic pain of 3/10 or greater. Pain and sensorimotor function were assessed at baseline, post-intervention, and 3-month follow-up using the Numeric Pain Rating Scale (NPRS), ASIA Impairment Scale (AIS), and Neuromuscular Recovery Scale (NRS). Functional MRI included resting-state and 4 tasks: imagining feeling the left leg, imagining moving the left leg, whole-body movement imagery, and a sensation task. Results: After CMR, participants improved on AIS with large effect sizes (touch: d=1.54; pinprick: d=1.83; lower limb motor function: d=1.32), while adaptive fitness had small/moderate effects (touch: d=0.49; pinprick: d=0.53; lower limb motor function: d=0.74). CMR also showed larger effect sizes for NRS (core: d=2.19; upper limb: d=0.69; lower limb: d=0.74) than fitness (core: d=0.73; upper limb: d=0.34; lower limb: d=0.00). Benefits persisted at follow-up. Highest neuropathic pain intensity reduced post-CMR and at 3-month follow-up (d=0.48; d=0.63). Pain increased slightly after fitness (n=6; d=-0.19; d=-0.41). CMR increased brain connectivity and activation during the leg imagery task. Increased activation during whole-body imagery was greater after CMR than fitness. Discussion: These preliminary results support the potential of CMR to improve function and reduce neuropathic pain in adults with SCI, warranting larger confirmatory trials. Clinicaltrial.gov: NCT05167032

BackgroundNeurodevelopmental impairment remains common in neonatal hypoxic-ischemic encephalopathy (HIE) despite treatment with the standard of care, therapeutic hypothermia (TH). The complement response activates at reperfusion and is known to exacerbate neuroinflammation and injury, though its full role and interaction with hypothermia are incompletely defined. We hypothesized that modulating the complement response could improve structural and functional outcomes in HIE, and tested a novel complement therapy (CT), consisting of C3a peptides and the C5a-receptor antagonist PMX205, as both a stand-alone treatment and as an adjuvant to TH. MethodsWistar rat pups were randomized to the following treatment groups: Sham (uninjured control), NT (uninjured, normothermia/not treated control), or injured and treated with either TH, CT, or CT+TH. At term-equivalence, mild-moderate hypoxic-ischemic injury was induced by Vannuccis method. To capture the short and long-term effects of the treatments, cohorts were harvested 3 or 66-72 days post-injury, respectively. Cerebral injury was measured by quantifying levels of inflammatory markers and cerebral tissue loss, and functional outcomes were assessed in a series of behavioral tests. The data were stratified to detect sexual dimorphisms. ResultsCT and TH treatments demonstrated test and sex-dependent differences in improvement compared to untreated, injured rats. In male rats, TH treatment worsened long-term hippocampal and thalamic brain injury and functional measures of ataxia and attention. CT-treatment worsened long-term thalamic loss in females. Combining the two treatments (CT+TH) demonstrated additive improvement in both sexes, including short and long-term cortical loss and ataxia. ConclusionsComplement modulation enhances the neuroprotective effects of TH after neonatal hypoxic-ischemic injury, with sex-specific effects on inflammation and behavior. Combining complement modulation with the standard of care often demonstrated synergistic improvement in both sexes, supporting complement-targeted therapy as a promising adjunct to hypothermia in neonatal HIE. Graphical abstract. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/717097v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1025d1forg.highwire.dtl.DTLVardef@2fa4e5org.highwire.dtl.DTLVardef@1f2c1c4org.highwire.dtl.DTLVardef@8f3410_HPS_FORMAT_FIGEXP M_FIG C_FIG Created with BioRender. Saadat, A. (2026) https://BioRender.com/siwm825.

Background Chronic subdural hematoma (cSDH) recurrence requiring reoperation occurs in 5-33% of cases, representing a substantial clinical and economic burden. The ability to predict recurrence could enable risk-stratified surveillance protocols, potentially reducing imaging burden in low-risk patients while maintaining close monitoring for high-risk individuals. We evaluated whether machine learning algorithms could achieve clinically actionable recurrence prediction using routinely available clinical and radiographic variables. Methods This retrospective single-center study included 564 consecutive patients who underwent surgical evacuation of cSDH between 2015 and 2023. Data were randomly divided into training (75%, n=422) and test (25%, n=142) sets. We developed and compared three machine learning models--regularized logistic regression, Random Forest, and XGBoost--using 31 predictor variables including demographics, comorbidities, medications, laboratory values, hematoma characteristics, and postoperative features. Model development and hyperparameter tuning were performed exclusively on the training set using 10-fold cross-validation. The best-performing model was selected and evaluated on the held-out test set. The primary outcome was postoperative recurrence requiring reoperation. Results Postoperative recurrence occurred in 170 patients (30.1%). Within the training set, XGBoost achieved the highest cross-validated ROC AUC of 0.713 (SE=0.024), outperforming regularized logistic regression (0.686) and matching Random Forest (0.713). Variable importance analysis identified hematoma volume, coagulation parameters (INR, platelets, aPTT), and disease severity markers (ICU admission, GCS) as the most influential predictors, though absolute effect sizes remained modest. On the held-out test set, the final XGBoost model achieved ROC AUC 0.688 (95% CI: 0.590-0.772) with excellent calibration. However, at the clinically relevant 90% sensitivity threshold, test set specificity was only 30.3%, allowing potential imaging reduction in approximately one-third of non-recurrence patients. The consistency between training and test performance confirmed that limitations stem from inherent predictor information content rather than overfitting. Conclusions Machine learning models using routinely available clinical and radiographic variables cannot achieve clinically actionable risk stratification for cSDH recurrence. Despite rigorous methodology and internal validation, discriminative capacity remained insufficient to identify a low-risk patient subgroup suitable for de-escalated surveillance. These findings suggest that recurrence is driven by factors not captured in standard clinical assessment, and support either uniform surveillance protocols or symptom-driven imaging strategies rather than risk-stratified approaches.

Spinal cord injury (SCI) pathology is highly difficult to treat due to substantial heterogeneity in injury presentation and spread, along with unclear mechanisms linking damage to pathology. Damages from injury forces (primary injury) are exacerbated by a series of biochemical events that follow the initial damage and injure additional tissue, known as secondary injury. Reactive aldehydes, such as acrolein, play a key role in propagating secondary injury cascades following SCI. Targeting acrolein after SCI has demonstrated therapeutic potential in limiting injury spread and pathology. However, injury mechanisms linking reactive aldehydes to SCI outcome have not been fully characterized. To gain a more comprehensive understanding of the cellular and molecular mechanisms underlying SCI, we generated proteomic profiles of rat spinal cords 24 h (acute phase) after subjection to SCI, sham injury, saline injection, or acrolein injection. We performed gene set enrichment analysis (GSEA) to characterize proteins and pathways significantly enriched after SCI and acrolein-injection. We then used Translatable Components Regression (TransComp-R), a framework for translating biological signatures across systems, to assess whether acrolein-associated spinal cord signatures can stratify SCI from sham outcomes. Our proteomics analysis revealed 467 differentially expressed proteins (DEPs) between the sham and SCI groups and 7 DEPs between saline and acrolein injection groups. Notably, the complement and coagulation cascades were upregulated in spinal cords subjected to SCI and acrolein injection. Our TransComp-R analysis further demonstrated that acrolein-associated signatures could distinguish SCI from sham conditions. Taken together, our findings suggest that acrolein induces proteomic alterations during the acute phase of SCI and is associated with complement and coagulation cascade activation, among other pathways. Therefore, this study reinforces the notion that understanding the role of acrolein in the acute phase of secondary SCI may be beneficial.