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PubMed2026

Thrombus Metabolism-Based Molecular Subtyping for Prognostic Risk Stratification in Acute Ischemic Stroke: A Preliminary Study.

AIMS: To preliminarily characterize metabolic molecular subtypes of cerebral thromboemboli and evaluate their clinical significance in anterior circulation acute ischemic stroke due to large vessel occlusion (AIS-LVO). METHODS: Untargeted metabolomics was performed on thromboemboli retrieved from 36 patients with anterior circulation AIS-LVO using ultra-performance coupled liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Unsupervised hierarchical clustering was employed to identify distinct metabolic molecular subtypes, and their associations with stroke etiology, radiographic severity, and functional outcomes were analyzed. RESULTS: Two distinct thrombus metabolic molecular subtypes (C1 and C2) were identified based on 12 metabolites significantly associated with both short-term (7-day ∆NIHSS) and long-term (90-day mRS) functional outcomes. The C1 subtype, predominantly cardioembolic, exhibited enhanced lipid metabolism, whereas the C2 subtype, primarily atherothrombotic, demonstrated increased folate metabolism. Patients with C1 thromboemboli presented more severe admission ischemic lesions (as indicated by ASPECTS) and experienced poorer short-term and long-term outcomes. A six-metabolite signature derived from LASSO regression was identified for exploratory discrimination of thrombus metabolic subtypes, etiological subtypes, and 90-day outcomes. CONCLUSION: This preliminary exploratory study identifies two metabolically distinct thrombus molecular subtypes with clinical implications in anterior circulation AIS-LVO, providing a novel basis for risk stratification and personalized secondary prevention and warrants further investigation.

Humans↗

PubMed2026

Blood pressure management after endovascular thrombectomy in acute ischemic stroke: association with symptomatic intracranial hemorrhage and functional outcome at 3 months.

BACKGROUND: No clear consensus exists on ideal systolic blood pressure (SBP) targets after endovascular thrombectomy (EVT) following an acute ischemic stroke (AIS). This study investigated the association between SBP parameters within the first 24 h after EVT and 3-month functional outcomes and the risk of symptomatic intracranial hemorrhage (sICH). METHODS: We retrospectively collected and prospectively followed clinical, and radiological data for patients undergoing EVT for AIS from 2016 to 2024, including 2-hourly BP measurements during the first 24 h and SBP variability assessed by standard deviation (SD) and coefficient of variation (CV). Outcomes included 3-month functional status and sICH, and their associations with post-EVT BP metrics were analyzed. RESULTS: A total of 268 post EVT patients were included with a median age of 61 years (IQR, 51-69). Mean SBP was 129.67 ± 17.17 mm Hg, with SBP variability (SD 12.6 ± 5.4 mm Hg; CV 9.6 ± 3.8 %), while good functional outcome and sICH occurred in 39.7 % and 4.9 % of patients, respectively. Multivariate regression showed that higher admission NIHSS (>15) [0.90 (95 %CI, [0.86, 0.95], p = 0.000)], recanalization status [1.88 (95 %CI, [1.43, 2.48], p = 0.00)], and SBP-CV ≥ 10 [0.44 (95 %CI, [0.2, 0.94], p = 0.036)] was independently associated with poor 3-month functional outcome, while higher admission NIHSS (>15) [0.87 (95 %CI, [0.77,0.98], p = 0.02)] and diabetes [0.12 (95 %CI, [0.03, 0.54], p = 0.006)] predicted increased risk of sICH. CONCLUSIONS: The study showed that reduced BP variability during the first 24 h post-EVT was associated with better 3-month functional outcomes. A clear association between SBP and sICH risk was not demonstrated.

Humans↗

PubMed2026

Restrictive vs Liberal Transfusion Strategy in Traumatic Brain Injury: A Secondary Analysis of the TRAIN Trial.

IMPORTANCE: Anemia is a prevalent condition among patients with traumatic brain injury (TBI); however, the optimal hemoglobin (Hb) threshold to initiate red blood cell transfusion (RBCT) is not well defined. OBJECTIVE: To assess which of 2 different Hb thresholds for guiding RBCT in patients with anemia and TBI is associated with a more favorable neurological outcome. DESIGN, SETTING, AND PARTICIPANTS: This was a preplanned secondary analysis of the Transfusion Strategies in Acute Brain Injured Patients multicentric randomized clinical trial, conducted in 72 intensive care units across 22 countries between September 1, 2017, and December 31, 2022. Follow-up was completed June 30, 2023. Only patients with TBI were included in the present analysis, conducted from February to May 2025. INTERVENTIONS: Liberal (transfusion at Hb <9 g/dL [to convert to g/L, multiply by 10.0]) vs restrictive (transfusion at Hb <7 g/dL) RBCT strategy over a maximum of 28 days. MAIN OUTCOME AND MEASURES: The primary outcome was the occurrence of unfavorable neurological outcome, defined as a Glasgow Outcome Scale Extended score of 1 to 5 (overall range, 1-8, with higher scores indicating more favorable outcome) at 180 days. In addition, 14 prespecified serious adverse events, including infection and cerebral ischemia, were assessed. Data were analyzed using both the intention-to-treat and per-protocol principles. RESULTS: Of 486 patients who presented with TBI (mean [SD] age, 46.8 [17.6] years; 347 [71.4%] male), 475 were included in the primary outcome analysis: 236 were randomized to the liberal transfusion strategy group and 239 to the restrictive transfusion strategy group. Both groups had similar baseline characteristics. In total, 534 RBCTs were administered in the liberal transfusion strategy group, compared with 246 RBCTs in the restrictive group. At 180 days after randomization, 138 patients (58.5%) in the liberal group had unfavorable neurological outcome compared with 161 patients (67.4%) in the restrictive group (relative risk [RR], 0.86 [95% CI, 0.75-1.00]; P = .047; fragility index = 1). There were no significant differences in the occurrence of secondary outcomes (eg, 28-day mortality: 42 of 240 [17.5%] vs 51 of 244 [20.9%]; RR, 0.84 [95% CI, 0.58-1.21]; P = .34) or serious adverse events (eg, RR, 1.13 [95% CI, 0.88-1.43]; P = .34 for infection and RR, 0.87 [95% CI, 0.40-1.90]; P = .72 for cerebral ischemia). After adjustment for several confounders, being randomized to the liberal group was associated with a lower observed probability of unfavorable neurological outcome (odds ratio, 0.60 [95% CI, 0.38-0.94]; P = .03). CONCLUSIONS AND RELEVANCE: In this secondary analysis of a multicenter randomized clinical trial, a liberal RBCT strategy was associated with a lower risk than a restrictive RBCT strategy of unfavorable neurological outcome at 180 days among patients with TBI. These findings should be interpreted with caution in light of the inherent uncertainty of the estimate. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02968654.

Humans↗

PubMed2026

Efficacy and safety of revascularization in patients with chronic limb-threatening ischemia by kidney function.

BACKGROUND: The optimal revascularization strategy for patients with chronic limb-threatening ischemia (CLTI) with chronic kidney disease (CKD) remains unknown. We evaluated whether the efficacy and safety of surgical vs endovascular revascularization differ by kidney function. METHODS: In this post hoc secondary analysis of BEST-CLI trial (NCT02060630), 1,704 patients with CLTI were stratified by baseline estimated glomerular filtration rate (eGFR, mL/min/1.73 m²): non-CKD (eGFR ≥ 90), mild-moderate CKD (eGFR 45-89), advanced CKD (eGFR < 45 or dialysis). The primary outcome was a composite of major adverse limb events (MALE) or death. We estimated the difference in restricted mean time lost (RMTL, in days) adjusted for inverse probability treatment weights. RESULTS: Surgical revascularization was significantly associated with fewer days with MALE or death in non-CKD (RMTL difference: -127.8 days; 95% CI -176.1, -79.6) and mild-moderate CKD (-63.2 days; 95% CI -104.7, -21.8) but not in advanced CKD (-16.4 days; 95% CI -78.8, 46.0; P interaction = .02). This attenuation reflected a diminishing mortality benefit with more severe CKD (P interaction = .01), whereas the association with fewer days with MALE remained consistent across CKD strata (P interaction = .34). Major adverse cardiovascular events and serious adverse events were more common with more severe CKD but did not differ significantly by treatment. CONCLUSIONS: Surgical vs endovascular revascularization was consistently associated with fewer days with MALE across CKD strata. However, its association with mortality varied by kidney function, attenuating the overall benefit for the composite endpoint of MALE or death. These results support individualized revascularization strategies, but require prospective confirmation. TRIAL REGISTRATION: The BEST CLI trial is registered at ClinicalTrials.gov (NCT02060630).

Humans↗

PubMed2026

Comparison between measured and synthesized posterior lead electrocardiograms during percutaneous coronary intervention-induced myocardial ischemia.

BACKGROUND: Posterior/inferolateral myocardial ischemia is frequently underrecognized on standard 12‑lead electrocardiography (ECG). Synthesized posterior leads derived from the standard 12‑lead ECG have been proposed as an alternative to directly measured posterior leads; however, their accuracy under controlled ischemic conditions has not been fully validated. METHODS: We prospectively enrolled 26 consecutive patients undergoing percutaneous coronary intervention (PCI) in whom simultaneously recorded measured and synthesized posterior lead ECGs (V7-V9) were obtained during balloon-induced myocardial ischemia. ST-segment deviation was measured at the ST junction (STJ), 40 ms (ST1), and 80 ms (ST2) thereafter. Agreement between measured and synthesized posterior leads was assessed using Pearson correlation and Bland-Altman analyses. As an exploratory patient-level analysis, diagnostic performance was compared with reciprocal anterior ST-segment depression (V1-V4). RESULTS: Strong correlations were observed between measured and synthesized posterior lead ST-segment deviations (V7: r = 0.89; V8: r = 0.86; V9: r = 0.83; all P < 0.001). Bland-Altman analysis demonstrated minimal systematic bias (within ±0.004 mV) and narrow limits of agreement. Synthesized posterior leads showed higher diagnostic performance than reciprocal anterior ST-segment depression (AUC 0.917 vs. 0.708), although the difference was not statistically significant (DeLong test, P = 0.197). Using a 0.05 mV threshold, synthesized posterior leads demonstrated 83.3% sensitivity, 100% specificity, and 96.2% overall accuracy. CONCLUSIONS: Synthesized posterior leads closely reproduced measured posterior lead ST-segment deviations during percutaneous coronary intervention (PCI)-induced myocardial ischemia, supporting the technical validity of posterior lead reconstruction. Larger prospective studies are warranted to determine whether synthesized posterior leads provide incremental diagnostic value beyond careful interpretation of the standard 12‑lead ECG.

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PubMed2026

Transverse Tibial Transport for Limb Salvage in Ischemic Lower Extremity Disease: Technique, Mechanisms, and Clinical Outcomes-A Systematic Review.

Transverse tibial transport (TTT) is a surgical technique derived from Ilizarov's distraction osteogenesis principles that stimulates angiogenesis and microcirculatory regeneration in the ischemic lower limb without directly manipulating macrovascular anatomy. By creating a proximal tibial cortical bone window and distracting it transversely using an external fixator, TTT triggers converging cascades of growth factor release, endothelial progenitor cell mobilization, and immunomodulation that translate into improved distal limb perfusion and wound healing. Combined TTT plus endovascular therapy improves amputation-free survival versus endovascular therapy alone. Prospective randomized trials and standardized international protocols are needed to consolidate TTT's role in multidisciplinary limb salvage pathways.

Humans↗

PubMed2026

A polygenic risk score for peripheral artery disease and major adverse limb events.

BACKGROUND AND AIMS: Large-scale genome-wide association studies have identified common genetic variants that predict the risk of peripheral artery disease (PAD). This study assessed whether a polygenic risk score (PRS) is associated with PAD and the incidence of major adverse limb events (MALE) independent of clinical risk factors in patients with established cardiometabolic disease. METHODS: A genetic analysis was performed, pooling individual patient-level data from six TIMI trials. The association of a recently validated PAD PRS with prevalent PAD and the incidence of MALE (acute limb ischaemia, chronic limb-threatening ischaemia, major amputation, or peripheral revascularization) was assessed. RESULTS: A total of 68 816 patients were included in this analysis, with a median follow-up of 2.6 years. Of these, 5986 (8.7%) had known PAD at baseline. After adjusting for clinical risk factors, a higher PAD PRS was independently associated with a 15% greater odds of prevalent PAD (adjusted odds ratio per 1-SD: 1.15 [95% confidence interval 1.12-1.18], P < .0001), a magnitude of risk as strong as established clinical risk factors. A total of 577 patients experienced MALE during follow-up. A higher PAD PRS was associated with a 30% increased risk of MALE (adjusted hazard ratio per 1-SD: 1.30 [1.19-1.42], P < .0001). Adding the PAD PRS to clinical risk factors resulted in a statistically significant but modest improvement in discrimination (area under the curve went from 0.651 to 0.662 P < .0001). CONCLUSIONS: In a broad spectrum of patients with cardiometabolic disease, the PAD PRS is associated with an increased risk of PAD and the incidence of MALE beyond clinical risk factors; however, the improvement in discrimination was statistically significant but clinically modest.

Humans↗

PubMed2026

Efficacy and Safety of Rivaroxaban in Patients with Peripheral Artery Disease: A GRADE-assessed Systematic Review and Meta-Analysis.

BACKGROUND: Peripheral artery disease (PAD) is a common atherosclerotic disorder characterized by progressive arterial narrowing in the limbs. This study aims to determine the efficacy and safety of rivaroxaban, focusing on major cardiovascular events, limb outcomes, and bleeding risks. METHODS: PubMed, Cochrane, and EMBASE were searched for randomized controlled trials (RCTs) and nonrandomized comparative studies that compared rivaroxaban, either alone or in combination with aspirin, to placebo or standard care such as antiplatelet therapy. Risk ratios and hazard ratios with 95% confidence intervals were pooled using R v4.5.1 with an appropriate random-effects model applied. Subgroup analyses were performed according to rivaroxaban plus aspirin versus rivaroxaban alone. RESULTS: A total of 39,991 participants across 6 studies were included. Compared with control, use of rivaroxaban was linked to a significant reduction in composite efficacy outcomes (relative risk [RR] = 0.84, 95% confidence interval [CI] 0.78-0.91, P < 0.001), risk of acute limb ischemia (RR = 0.65, 95% CI 0.55-0.78, P < 0.001), and thromboembolism (RR = 0.60, 95% CI 0.38-0.97, P = 0.037). Although rivaroxaban plus aspirin failed to show a significant reduction in the risk of amputation, rivaroxaban alone reported a significant risk reduction (RR = 0.50, 95% CI 0.30-0.85, P = 0.003). However, its use was associated with a significantly higher risk of major bleeding (hazard ratio [HR] = 1.54, 95% CI 1.38-1.72, P < 0.001) and International Society on Thrombosis and Hemostasis-defined bleeding (RR = 1.45, 95% CI 1.19-1.76, P < 0.001). No significant differences were observed for stroke, myocardial infarction, major adverse limb events, fatal bleeding, mortality, or cardiovascular mortality. CONCLUSION: Rivaroxaban-based therapy reduced the trial-defined composite efficacy outcome, acute limb ischemia, and thromboembolism in patients with PAD, but increased the risk of major bleeding. These findings support individualized use of rivaroxaban-based therapy in carefully selected patients, balancing ischemic and limb-protective benefits against bleeding risk.

Humans↗

PubMed2026

Magnesium administration for vasospasm prevention in acute aneurysmal SAH: a multicenter randomized controlled trial.

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with significant morbidity and mortality, with cerebral vasospasm (CV) and delayed cerebral ischemia (DCI) being the primary contributors to poor outcomes. Magnesium sulfate (MgSO₄) has demonstrated neuroprotective and vasodilatory properties in preclinical models. This study aimed to evaluate the effect of targeted serum magnesium (Mg) maintenance on CV and exploratory clinical outcomes following aSAH. We conducted a prospective, multicenter, single-blind RCT across four neurocritical care units in Korea between 2019 and 2024. A total of 121 aSAH patients were randomized to receive either IV MgSO₄or placebo within six hours of admission. Mg was infused to maintain serum concentrations between 2.0 and 3.0 mg/dL for 14 days. The primary outcome was incidence of CV assessed by transcranial doppler. Secondary outcomes included DCI, ICU and hospital length of stay, modified rankin scale (mRS) at 30 days. There was no significant difference in overall CV incidence; however, the Mg group demonstrated significantly lower mean flow velocity and Lindegaard ratio on days 4-9, indicating reduced vasospasm severity. In exploratory multivariable analyses, a median serum Mg concentration > 2.5 mg/dL during the first 14 hospital days was independently associated with lower risks of CV and DCI. No significant differences were found in mRS scores, ICU and hospital stay, or serious adverse events between groups. Early targeted Mg administration improved TCD-derived hemodynamic markers during the peak vasospasm window; however, it did not significantly reduce CV incidence, DCI, ICU or hospital stay, or 30-day functional outcome.

Humans↗

PubMed2025

The effect of penile tourniquet and continuous artificial erection on penile erectile tissues: An experimental study.

INTRODUCTION: Penile tourniquet (PT) is known to cause ischemic injury, which worsens with prolonged application. Artificial erection (AE), formed by intracorporal saline injection mostly under PT, has been practiced for decades to evaluate penile curvature, yet its effect on erectile tissues has never been investigated. In this study, we examined a modified approach, continuous artificial erection (CAE), and investigated its effects on erectile tissues. OBJECTIVE: This study aims to investigate the histopathological and immunohistochemical effects of CAE on penile erectile tissues. STUDY DESIGN: Thirty-five rats were randomized into five groups. Four experiment groups received 20 or 40 min of isolated PT (20T and 40T) or PT with CAE (20T&E and 40T&E). CAE was achieved through continuous intracavernosal saline injection. Penectomy was performed three weeks post-procedure in the experiment groups and directly in the control group. Erectile tissue samples were evaluated using light microscopy for histopathological parameters including inflammation, neovascularization and fibrosis, and by immunohistochemistry. Endothelial function was assessed by eNOS and e-selectin staining, while ICAM-1 staining was used to assess chronic inflammation. RESULTS: 40T showed the highest levels of inflammation, fibrosis, and endothelial dysfunction. 20T had significantly less inflammation than 40T, with a non-significant increase in fibrosis and alteration of endothelial markers. 40T&E displayed the second-highest fibrosis rate (adjusted p > 0.05), while 20T&E showed complete absence of fibrosis. Both 40T&E and 20T&E preserved strong eNOS and e-selectin expression, identical to controls. ICAM-1 expression in 20T&E was also consistent with the control group. The most significant difference in erectile tissue damage was noted between 40T and 20T&E. CONCLUSION: This is the first study to evaluate the effects of AE on erectile tissues. Findings of this experimental model support that, CAE does not increase the tissue damage that is already caused by PT, but rather reduces it, likely through the washout of blood elements contributing to reperfusion injury. CAE possibly provides a protective effect on erectile tissues by preserving endothelial function, reducing inflammation and fibrosis, especially under 20 minutes of duration. These findings may support that AE maneuvers such as "artificial erection test" and CAE are potentially safe, while further studies are needed to assess the detailed effects of CAE.

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PubMed2026

Bypassing the emergency department for testicular torsion.

BACKGROUND: Testicular torsion is a time-sensitive urologic emergency that can result in testicular ischemia, atrophy, and loss if detorsion is delayed. Patients transferred from outside hospitals oftentimes experience prolonged ischemia due to repetitive assessments in the receiving emergency department (ED) and lengthy interhospital transfers. To address these delays, our institution created a pathway allowing patients with a confirmed diagnosis of testicular torsion to bypass the ED and proceed directly to the OR. OBJECTIVE: To evaluate the efficacy of an emergency department bypass pathway on time to surgical intervention and testicular salvage rates for patients transferred from outside hospitals with confirmed testicular torsion. STUDY DESIGN: Following one year of pathway implementation and institutional review board approval, a retrospective chart review was performed. Patients aged 12-18 years that were transferred from outside hospitals for confirmed testicular torsion were included in the pathway. A pre-pathway cohort (January 2022-December 2022) of patients with ED management was compared to a post-pathway cohort (August 2023-September 2024) of patients managed via direct OR transfer. Comparisons included patient age, mean time from ED registration to surgery start, orchiectomy rates, testicular atrophy rates at follow-up, and overall length of follow-up. T-tests and Fisher's exact tests were used for statistical analysis. RESULTS: 71 patients were included. Mean time from registration to OR start was significantly shortened in the post-pathway cohort compared to the pre-pathway cohort (70 min vs. 23 min, p < 0.0001). This represents a 67% decrease in time to surgery. Post-pathway patients were significantly older than pre-pathway patients (15 years vs. 13 years, p = 0.0025). Orchiectomy rates did not significantly differ between the two groups (14% post-pathway and 28% pre-pathway, p = 0.2454). Similarly, no significant difference was observed for testicular atrophy at follow-up (17% post-pathway and 15% pre-pathway, p = 1.0). Mean length of follow-up was insignificant (90 days for post-pathway and 76 days for pre-pathway, p = 0.6605). DISCUSSION: Direct transfer to the OR with ED bypass significantly reduced time to surgical detorsion. Other variables such as orchiectomy and testicular atrophy rates were not significantly impacted. Patient-limited factors may have influenced outcomes, such as delays in symptom recognition and time to initial care. CONCLUSION: An ED bypass pathway for transferred patients with testicular torsion was highly effective at reducing time to surgical intervention. Although testicular salvage rates were not significantly affected, reducing ischemia time is clinically important and encourages pathway refinement and broader use.

Humans↗

PubMed2026

Understanding specificity in immune-brain pathways: A systematic review of differential associations between individual cytokines and brain structure and function measured through magnetic resonance imaging in humans.

Research shows that cytokines are associated with psychiatric disorders, including major depression, and multiple aspects of brain structure and function. Accumulating data suggest that different cytokines may have unique profiles of biological activity, particularly in their neuromodulatory roles, but it is currently unclear whether they have unique associations with specific neural circuits in humans. In this paper, we systematically review magnetic resonance imaging studies conducted with depressed or healthy control human participants under age 65 that examine associations between peripheral cytokines and brain structure and function, with the goal of evaluating evidence for the specificity of these cytokine-brain associations. We find that across multiple measures of brain structure and function, the majority of studies reviewed reported unique associations between individual cytokines and brain outcomes. A synthesis of findings across studies also suggests a preliminary hypothesis of specific associations of interleukin-6 levels in circulation with the default mode network and tumor necrosis factor-alpha with the salience network, which could be tested in future research. We conclude the review with future directions for research that can strengthen understanding of these associations.

Humans↗

PubMed2026

Accurate quantification of canine mitochondrial DNA copy number from canine blood and brain samples.

Acute brain injury is difficult to evaluate in veterinary medicine and tools to investigate the potential involvement of mitochondrial involvement are limited. The brain is highly enriched in mitochondria and contains thousands of copies of mitochondrial DNA (mtDNA) per cell, but robust methods for quantifying mitochondrial DNA copy number (mtDNA-CN) in canine tissues are lacking. We describe the development of a quantitative real-time PCR assay for absolute measurement of mtDNA-CN which was validated in canine blood and brain tissue. To minimize amplification of nuclear mitochondrial insertion sequences (NumtS) and repetitive regions, species-specific oligonucleotide primers were designed following in silico genomic filtering. The assay was applied to a small pilot cohort comprising blood samples from dogs with and without acute brain injury (n = 4-6 per group) and cerebral cortex samples (n = 1 per group) to assess feasibility and biological plausibility. In non-brain injury dogs, blood mtDNA-CN ranged from 98 to 288 copies per nuclear genome (mean 193 ± 72), while values in brain-injured cases ranged from 163 to 228 copies per genome (mean 200 ± 33). Cerebral cortex samples exhibited higher mtDNA-CN than blood, consistent with known tissue-specific mitochondrial enrichment. In a single brain-injured case with serial sampling, mtDNA-CN increased over five days. This study presents a validated assay and pilot data for mtDNA-CN quantification in canine samples. While not powered for biomarker evaluation, this method may enable future studies of mitochondrial dynamics in canine brain injury and metabolic disease.

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PubMed2026

The role of artificial intelligence in the diagnosis and prognosis of traumatic brain injury based on brain CT scans: a systematic review.

Traumatic brain injury (TBI) is a leading cause of emergency department visits and a major contributor to injury-related mortality and long-term neurological disability. Non-contrast computed tomography (CT) is the gold-standard imaging modality for the rapid diagnosis of TBI. Clinical outcomes depend strongly on early detection and prompt acute management. Artificial intelligence (AI)-based models may support faster automated identification of traumatic findings and early prediction of patient prognosis. A systematic literature search was conducted in PubMed/MEDLINE, Scopus, IEEE Xplore, ACM Digital Library, and the Cochrane Library in accordance with PRISMA 2020 guidelines to evaluate AI-based models for automated detection of TBI-related findings on CT and for prediction of clinical outcomes. Risk of bias and applicability were assessed using QUADAS-2 for diagnostic accuracy studies and PROBAST + AI for prediction model studies. Twenty-two studies were included. Sixteen studies evaluated diagnostic tasks and 10 evaluated prognostic outcomes, with four studies contributing to both categories. Diagnostic performance was generally high, with many studies reporting AUC values approaching or exceeding 0.90, particularly for larger lesion volumes.Prognostic performance was more variable, with moderate to high discrimination and substantial heterogeneity. Only 9 studies incorporated independent external validation, and performance was frequently lower in external cohorts. All prognostic model studies were judged to be at high overall risk of bias using PROBAST + AI, and most diagnostic accuracy studies also demonstrated high or unclear risk of bias in at least one QUADAS-2 domain, most frequently in patient selection. AI-based models applied to brain CT demonstrate strong technical performance for both diagnostic and prognostic tasks in TBI. However, most studies relied on retrospective designs and lacked independent external validation which limits models generalizability and raises concern for potential overfitting. Prospective, multicenter studies with standardized methodologies and rigorous external validation are required before widespread clinical implementation.

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PubMed2026

A systematic review of macaque brain stimulation: Trends and future directions.

Neurostimulation techniques can powerfully modulate neural circuit activity and provide causal insights into the relationship between brain function and behavior. Macaque monkeys have long been a key animal model for brain stimulation studies. While stimulating the macaque brain with one or a few electrodes has already taught us much about brain function and dysfunction, recent technological advances promise a future with more precise stimulation using many more electrodes. However, such possibilities also increase the number of choices an experimenter has when designing their study. We can learn from a rich past, but a comprehensive overview of which brain regions have been studied and with what stimulation parameters is lacking. Here, we present a PRISMA-compliant systematic review of 734 macaque brain stimulation studies using electrical and/or optogenetic stimulation. We find a striking bias in which brain areas have traditionally been stimulated: a mere 10 brain regions account for half of all studies, with the remainder of studies investigating approximately 150 other areas. Across studies, stimulation frequency robustly predicted direct behavioral effects independent of brain region, while amplitude did not. Future studies could more systematically explore less studied regions through lower stimulation frequencies (e.g., 20-50 Hz) alongside established ranges (∼200 Hz). Tools such as fMRI or optical imaging can capture neural circuit engagement evoked by these frequencies, even when behavioral effects are absent or remain subtle. Our synthesis offers a guide towards the next steps in high-channel-count, high-precision stimulation approaches.

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PubMed2026

Somatic mutations: recent advances in brain aging and neurodegeneration.

Somatic mutations are genetic variants that occur after the single-cell phase of development and have been implicated in disease pathogenesis. While most DNA lesions are detected and repaired, examination of healthy tissue has revealed that some lesions escape repair, leading to somatic mutations that accumulate at a consistent rate, including in human brain tissue and postmitotic neurons. Emerging methodological and analytical advances have revealed the presence of persistent mutagenic mechanisms during healthy brain aging as well as mutational pattern shifts in the context of neurodegenerative diseases. Here, we highlight recent methodological advances, summarize our current understanding of somatic mutagenesis in neurotypical brain aging, and examine the role of somatic mutations in neurodegenerative diseases.

Humans↗

PubMed2026

Origins and timing of somatic variants in the brain.

Somatic variants accumulate in human brain cells throughout the lifespan. Variant allele fraction has traditionally been used as a proxy for both the developmental timing of somatic variants and their functional effect, based on the assumption that earlier mutations are shared by larger cell populations and therefore have greater potential for severe phenotypes. However, recent discoveries challenge this simplified model. Variables such as developmental bottlenecks, lineage restriction, and cellular and molecular context play critical roles in shaping the distribution and functional impact of somatic variants in the brain. These insights support a shift toward a context-dependent framework for interpreting somatic mosaicism.

Humans↗

PubMed2026

Strategies for mosaic variant calling in brain disorders.

The human brain is a genomic mosaic, where postzygotic mutations arising from embryogenesis to senescence drive diverse neurodevelopmental and neurodegenerative diseases. Because of numerous sequencing artifacts at ultralow variant allele frequencies (VAFs), detecting these variants remains a significant analytical challenge. This review focuses on single-nucleotide variants and small indels, summarizing current strategies for aligning sampling methods, including bulk, laser capture microdissection, and single-cell genomics, with the expected clonal architecture of the brain. It emphasizes that mosaic detection sensitivity is fundamentally constrained by sequencing depth, since even the most advanced algorithms cannot identify variants not physically represented in the sequencing library. The review further recommends the selection of variant calling algorithms based on validated VAF detection performance, matching tools like MuTect2 and MosaicForecast to their optimal performance ranges. Furthermore, we discuss how multitissue sampling, as emphasized by the SMaHT project, addresses the matched-control dilemma and supports accurate variant classification via cross-tissue VAF gradients. Integrating these established pipelines with multiomics modalities, including transcriptomic and epigenetic data, could advance the field toward a functional understanding of how the somatic genome impacts human brain health and disease.

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