After retaining the index hospitalization that met a strict definition of aneurysmal subarachnoid hemorrhage, 370 patients remained eligible. The longitudinal trajectory cohort included 318 patients with an albumin measurement within 48 hours of admission and measurements on at least three different days during days 0–14. Mean age was 60.5 years; 183 patients underwent microsurgical clipping, 126 received endovascular treatment, and nine received both.

Latent class mixed models with patient-specific random intercepts were used to identify longitudinal albumin patterns. Two-, three-, and four-class solutions with alternative time functions were compared using statistical fit, Bayesian information criterion, entropy, posterior membership probabilities, class size, and clinical interpretability. The selected three-class model used a natural cubic spline with four degrees of freedom and classified 90 patients as high-preserved, 148 as high-declining, and 80 as low-persistent.

The high-declining group began with albumin values close to those of the high-preserved group before falling rapidly to approximately 31–32 g/L, whereas the low-persistent group began with lower concentrations and remained low. The primary outcome was an unfavorable neurological status at discharge, defined as a modified Rankin Scale score of at least 3. Overall, 114 of 318 patients, or 35.8%, had this outcome.

It occurred in 13 of 90 patients in the high-preserved group (14.4%), 67 of 148 in the high-declining group (45.3%), and 34 of 80 in the low-persistent group (42.5%). In the principal complete-case analysis of 258 patients, adjustment for age, sex, treatment modality, hypertension, and a baseline severity indicator produced adjusted odds ratios of 3.65 (95% CI, 1.57–8.47; p=0.003) for the high-declining trajectory and 2.48 (95% CI, 1.02–6.02; p=0.044) for the low-persistent trajectory, each compared with the high-preserved trajectory; the global p value was 0.007. Those estimates did not demonstrate that either non-preserved trajectory was associated with a worse outcome than the other.

A direct adjusted comparison of high-declining with low-persistent albumin yielded an odds ratio of 1.47 (95% CI, 0.76–2.83; p=0.248). Albumin measured within 48 hours was not significantly associated with discharge outcome after adjustment, with an odds ratio of 0.97 per 1 g/L increase (95% CI, 0.91–1.03; p=0.286). Nadir albumin during days 0–14 was associated with the outcome, with an adjusted odds ratio of 0.76 per 1 g/L increase (95% CI, 0.69–0.84; p<0.001), although this post-baseline measurement may reflect evolving illness.

Landmark analyses supported a temporal association without eliminating reverse causation. After excluding patients who had been discharged or died by each landmark and requiring at least two measurements in the relevant window, each 1 g/L higher early nadir albumin was associated with lower odds of subsequent unfavorable discharge status. The adjusted odds ratio was 0.86 (95% CI, 0.79–0.93) in the day-3 analysis of 216 patients with 84 events and 0.84 (95% CI, 0.77–0.91) in the day-7 analysis of 250 patients with 91 events; both p values were below 0.001.

Restriction to patients with an available Hunt–Hess grade and multiple imputation for missing baseline severity produced trajectory associations in the same general direction. Sensitivity analyses also showed uncertainty in the trajectory findings. There was no evidence of a trajectory-by-treatment interaction between clipping and endovascular treatment (p=0.453), although treatment selection was not randomized.

Adjustment for recorded pneumonia, cerebral infarction, hydrocephalus, and intracranial infection attenuated the low-persistent estimate to 2.09 (95% CI, 0.81–5.41; p=0.129), while the high-declining estimate remained 3.35 (95% CI, 1.37–8.15; p=0.008). Adding trajectory class to a clinical model provided only a modest increase in apparent discrimination. The C-statistic rose from 0.754 to 0.776.

After 1,000 bootstrap resamples with class assignments held fixed, the optimism-corrected values were 0.735 and 0.753, respectively. The three-class model had only moderate separation, with entropy of 0.520, and 33% of patients had an assigned posterior probability below 0.70. A two-class spline model had the lowest Bayesian information criterion, only 1.72 points below the selected three-class solution, and the bootstrap procedure did not re-derive the trajectory classes.

The observational, single-center design limits causal inference and generalizability. Trajectory membership and nadir albumin incorporated measurements through day 14, when complications, treatment, nutritional changes, or deterioration could already have affected albumin levels. Routine rather than fixed laboratory testing meant fewer observations later in follow-up, while potential confounders including exogenous albumin administration, cumulative fluid balance, nutritional delivery, organ dysfunction, and delayed cerebral ischemia were not consistently available.

Some discharge modified Rankin Scale scores were retrospectively adjudicated, and standardized 90-day scores were not systematically available. The authors therefore characterized serial albumin trajectories as markers of the evolving systemic and clinical course rather than independently validated predictors, with prospective multicenter validation and standardized long-term outcome assessment needed.

Subject of Research: Association of longitudinal serum albumin trajectories with discharge neurological status after aneurysmal subarachnoid hemorrhage

Article Title: Longitudinal serum albumin trajectories and neurological outcomes after aneurysmal subarachnoid hemorrhage

Article References: Tang, H., Tang, Y., Wu, S., Zhang, Q., & Gong, Y. (2026). Longitudinal serum albumin trajectories and neurological outcomes after aneurysmal subarachnoid hemorrhage. Frontiers in Nutrition, 13, Article 1979070. https://doi.org/10.3389/fnut.2026.1979070

Image Credits: AI Generated

DOI: 10.3389/fnut.2026.1979070

Keywords: aneurysmal subarachnoid hemorrhage, serum albumin, albumin trajectories, neurological outcome, modified Rankin Scale, latent class mixed model, retrospective cohort, clinical nutrition, Longitudinal, serum, albumin, trajectories

The modified Rankin Scale, first described in the 1950s, grades functional independence on an ordinal scale from zero, meaning no symptoms at all, to six, meaning death. Because clinical trials needed a single binary endpoint to power their sample-size calculations, the scale was cleaved into two categories: zero to two, roughly corresponding to independent living, and three to six, spanning moderate disability through death. The approach has genuine practical value, but it collapses a vast spectrum of human function into two bins. For patients who were already disabled before their stroke, the upper bin is mathematically unreachable, no matter how well their treatment goes. Premorbid disability cutoffs have, by some estimates, excluded more than a third of stroke patients over age 65 from most major trials.

The Aachen team, led by Julia-Laura Schulz and João Pinho, mined a prospective single-center stroke registry covering admissions from January 2010 to December 2022. Of 3,724 ischemic stroke patients, 2,070 had complete documentation of their pre-stroke, admission, discharge and 90-day mRS scores and formed the final cohort. Their median age was 75.7 years, 47.4 percent were women, and the comorbidity burden was heavy: 80.5 percent had arterial hypertension, 38.8 percent atrial fibrillation and 26.5 percent diabetes. Critically, 243 patients, 11.7 percent of the cohort, carried a pre-stroke mRS of three to five, meaning they were already disabled before the index event. For these patients, the study argues, the conventional endpoint was decided before the stroke ever occurred.

The headline numbers confirm the problem. Among the 1,827 patients with a favorable pre-stroke score of zero to two, only 47.6 percent achieved a favorable outcome at discharge and 47.5 percent at 90 days. Among the pre-stroke disabled group, by definition, not a single patient achieved a favorable outcome, regardless of treatment. Yet when the investigators instead asked whether patients had returned to their exact pre-stroke mRS score, a point-wise, directional measure of recovery to one’s own baseline, the picture changed. At discharge, 16.2 percent of the favorable group and 19.3 percent of the unfavorable group had returned to baseline, a difference that was not statistically significant. At 90 days the figures were 21.8 versus 11.9 percent, and simply adding baseline-returners to the favorable pool lifted overall favorable outcome rates from 42.0 to 44.3 percent at discharge and from 41.9 to 43.3 percent at 90 days, both statistically significant shifts.

The most technically interesting result emerges from the multivariable logistic regression models, which adjusted for pre-stroke mRS group, age, sex, admission stroke severity measured by the NIHSS, treatment modality and vascular territory. An unfavorable pre-stroke mRS showed no association with returning to baseline at 90 days in the full cohort, with an odds ratio of 1.02. But it was strongly associated with death by 90 days, with an odds ratio of 4.40, and among survivors alone it was actually associated with a higher probability of returning to baseline, with an odds ratio of 2.34. As the authors put it in substance, premorbid disability acts primarily as a risk factor for death rather than as an obstacle to functional recovery in those who survive.

This survivorship effect is the analytical heart of the paper. Among patients alive at the 90-day mark, 50.0 percent of the unfavorable pre-stroke group had returned to baseline at discharge, compared with only 20.8 percent of the favorable group, and by 90 days the two groups had converged to 37.2 versus 28.4 percent. The apparent decline in recovery among disabled patients over time, from 19.3 percent at discharge to 11.9 percent at 90 days, was driven almost entirely by mortality rather than by functional deterioration, since death removes patients from the denominator before their recovery can be observed. The authors are careful to note a statistical subtlety: because the absolute functional gain required to reach one’s own baseline shrinks as baseline disability rises, return to baseline is a relative endpoint and should complement, not replace, absolute measures of independence.

The metric also passes a crucial validation test: it responds to treatment. In a model restricted to the 1,154 endovascularly treated patients and additionally adjusted for reperfusion grade, successful recanalization, defined as TICI 2b, 2c or 3, was independently associated with returning to baseline at 90 days, with an odds ratio of 3.46. The point estimate remained directionally similar among survivors alone. The authors frame treatment coefficients as associations with the treatment actually received rather than causal effects, a necessary caveat given that treatment allocation followed clinical judgment in a non-randomized cohort. Still, the finding that the new endpoint tracks procedural success in the same direction as established endpoints strengthens the case that it is measuring something clinically real.

The findings align with external evidence. The MR CLEAN Registry reported a 27 percent return-to-baseline rate among pre-stroke dependent patients undergoing thrombectomy, and a pooled meta-analysis of thrombectomy in patients with pre-existing disability found a roughly 30 percent rate. The Aachen cohort’s crude 11.9 percent is lower because it is unselected for treatment, includes patients who received no reperfusion therapy at all, and demands exact equality with the pre-stroke score; among survivors alone, the 37.2 percent rate is closely comparable. The study also situates itself against the HERMES collaboration’s ordinal shift analysis, which softened the dichotomy but still ignored each patient’s pre-stroke functional status and therefore cannot register return to baseline.

The authors are candid about limitations. The design is retrospective and single-center, 90-day scores were often collected by telephone with attendant recall and reporting biases, and missing mRS values excluded 1,654 patients, a source of possible selection bias. Stroke etiology and infarct size were not modeled, leaving residual confounding possible. The mRS itself weights motor deficits far more heavily than cognitive ones, so a patient can score well yet harbor serious cognitive impairment, and because the scale is ordinal rather than interval, a one-point change does not mean the same thing at every level of the scale. Return to baseline mitigates but does not eliminate this problem: recovering from mRS four to a pre-stroke score of three is not functionally equivalent to recovering from five to four, yet both count identically.

Nevertheless, the practical implication is clear and, the authors argue, essentially free to implement. Adding return to baseline alongside the conventional dichotomy reclassifies success for the roughly one in eight patients whose conventional endpoint was unattainable from the outset, and could guide more tailored care strategies, particularly for elderly patients with higher pre-stroke disability. An unfavorable score of three to five, the study concludes, does not necessarily signal treatment failure; in the right patient it can represent a better outcome than a favorable score in someone else. In an aging world where multimorbid patients make up a growing share of stroke admissions, outcome measures that judge patients against their own former lives, rather than an abstract ideal of independence, may finally let modern stroke therapies show what they can do for everyone they treat.

Subject of Research: Redefining favorable outcomes in ischemic stroke using return to pre-stroke modified Rankin Scale score

Article Title: Rethinking favorable outcomes: “return to baseline” as an additional outcome in ischemic stroke

Article References: Schulz, J.-L., Reich, A., Weyland, C. S., Ridwan, H., Hasan, D., May, R., Wiesmann, M., Nikoubashman, O., & Pinho, J. (2026). Rethinking favorable outcomes: “return to baseline” as an additional outcome in ischemic stroke. Frontiers in Neurology, 17, Article 1866829. https://doi.org/10.3389/fneur.2026.1866829

Image Credits: AI Generated

DOI: 10.3389/fneur.2026.1866829

Keywords: ischemic stroke, modified Rankin Scale, stroke outcomes, return to baseline, pre-stroke disability, endovascular treatment, thrombolysis, functional recovery, clinical trials, stroke registry, mortality, neurorehabilitation

The research, published in Frontiers in Neurology, followed 507 patients with mild acute ischemic stroke who received intravenous thrombolysis between January 2024 and June 2025. Ninety days after treatment, neurologists assessed each patient using the modified Rankin Scale, the standard yardstick of stroke recovery. A score of zero or one, meaning no symptoms or no significant disability, was considered an excellent outcome. Anything from two to six, ranging from mild restriction to death, was classified as non-excellent. The result was sobering: 136 patients, or 26.8 percent, fell into that latter category despite having strokes mild enough that many clinicians would have expected near-complete recovery.

That figure is not an anomaly. Previous studies have estimated that between 20 and 35 percent of patients with minor stroke fail to achieve excellent functional status at three months even after timely thrombolysis. What makes the new work distinctive is its focus. Most existing prediction models lump together patients of all severities, or rely on variables such as in-hospital complications that only become known after treatment has begun. Neither approach helps a physician standing at the bedside deciding how aggressively to monitor a patient whose stroke looks trivial. The Tianjin team deliberately restricted their model to information available at admission, before the first drop of alteplase or tenecteplase entered the vein.

The technical pipeline reflects current best practice in clinical machine learning. The researchers first applied LASSO regression, a statistical technique that shrinks the coefficients of uninformative variables to zero, effectively performing automatic feature selection. From a wide panel of demographic, clinical, laboratory, and neuroimaging variables, LASSO retained just six predictors: age, baseline NIHSS score, platelet count, monocyte count, blood glucose level, and the neutrophil-to-lymphocyte ratio, a widely used marker of systemic inflammation. Six variables, all obtainable from a standard complete blood count and chemistry panel, became the raw material for seven competing algorithms.

Those algorithms spanned the spectrum of modern machine learning, from classical logistic regression and decision trees to random forests, support vector machines, artificial neural networks, and two gradient-boosting methods, XGBoost and LightGBM. Each of the six non-linear models underwent hyperparameter optimization through grid search combined with stratified five-fold cross-validation, a procedure that repeatedly partitions the training data to find the settings that generalize best. The dataset was split 70:30 into training and internal validation cohorts using stratified random sampling, with a fixed random seed to guarantee reproducibility. When the dust settled, XGBoost, an algorithm that builds an ensemble of decision trees in which each new tree corrects the errors of its predecessors, emerged as the top performer.

On the validation cohort, XGBoost achieved an area under the receiver operating characteristic curve of 0.753, with a 95 percent confidence interval of 0.660 to 0.840. That number, while not spectacular, is respectable for a prediction made from six routine variables, and it edged out the support vector machine at 0.750 and logistic regression at 0.747. The decision tree fared worst at 0.614. Beyond raw discrimination, the team evaluated calibration, how closely predicted probabilities match observed outcomes, using calibration curves and the Brier score, and clinical usefulness through decision curve analysis, which compares the net benefit of acting on the model’s predictions against treating everyone or no one. XGBoost performed adequately on all three fronts, with a Brier score of 0.165.

What elevates the study above a simple algorithm bake-off is its commitment to interpretability. Black-box predictions are notoriously hard for clinicians to trust, so the researchers turned to SHAP, or Shapley Additive Explanations, a technique borrowed from cooperative game theory that assigns each predictor a contribution value for every individual prediction. The SHAP analysis ranked the baseline NIHSS score as the single most influential predictor, followed by blood glucose, age, platelet count, the neutrophil-to-lymphocyte ratio, and monocyte count. Crucially, the direction of each association was consistent with clinical intuition: higher values of every one of the six predictors pushed the model’s output toward a higher probability of poor recovery.

The biology behind those predictors is plausible and, in several cases, well supported by prior literature. Elevated admission glucose has long been linked to worse outcomes after thrombolysis, partly because stress hyperglycemia amplifies oxidative stress, promotes lactate accumulation, and disrupts the blood-brain barrier, increasing the risk of hemorrhagic transformation. A high neutrophil-to-lymphocyte ratio signals an innate immune system in overdrive: neutrophils infiltrating the ischemic brain release reactive oxygen species, matrix metalloproteinase-9, and neutrophil extracellular traps that damage the blood-brain barrier and clog the microvasculature, while lymphocytes, depleted by stroke-induced immunosuppression, can no longer restrain the damage. Even a successful recanalization of the large occluded artery can be undermined by this no-reflow phenomenon at the capillary level.

Platelet count is the most counterintuitive of the six predictors, since higher platelets might seem protective in a disease defined by clotting. Yet the SHAP dependence plots suggested a threshold-like pattern, with counts above roughly 280 to 300 billion per liter associated with higher predicted risk. The authors point to thromboinflammation: activated platelets adhere to injured endothelium and bind leukocytes through molecules such as P-selectin, forming aggregates that promote microvascular thrombosis and endothelial dysfunction. They are careful to note that this is a model-based predictive association, not proof of causation, and that SHAP attributions can be distorted by correlations among predictors. The same caution applies to the entire model, which the researchers frame as an adjunct to, not a replacement for, clinical judgment.

The study’s limitations are acknowledged candidly. It was retrospective and single-center, with internal validation only, so generalizability across institutions and populations remains unproven. The XGBoost model’s sensitivity of 0.525 means roughly half of the patients who ultimately fared poorly were not flagged, a meaningful gap for any screening tool. The cohort contained only nine patients treated with tenecteplase, precluding any analysis of whether the choice of thrombolytic matters. Still, the authors argue that the model’s real value lies in what it enables at the bedside: patients identified as high risk could receive closer neurological monitoring, earlier rehabilitation assessment, more aggressive management of modifiable factors such as glucose, and tighter follow-up after discharge. For a patient population often dismissed as low-risk, a six-variable algorithm that whispers a warning before the needle goes in could, if validated externally, change how mild strokes are managed.

Subject of Research: Machine learning prediction of 90-day functional outcomes after intravenous thrombolysis in mild acute ischemic stroke

Article Title: Machine learning-based models to predict 90-day non-excellent functional outcomes among patients with mild acute ischemic stroke after intravenous thrombolysis

Article References: Wang, Y., Qiu, X., Wang, Y., & Wang, L. (2026). Machine learning-based models to predict 90-day non-excellent functional outcomes among patients with mild acute ischemic stroke after intravenous thrombolysis. Frontiers in Neurology, 17, Article 1960403. https://doi.org/10.3389/fneur.2026.1960403

Image Credits: AI Generated

DOI: 10.3389/fneur.2026.1960403

Keywords: acute ischemic stroke, intravenous thrombolysis, machine learning, XGBoost, SHAP, neutrophil-to-lymphocyte ratio, modified Rankin Scale, blood glucose, platelet count, risk stratification, explainable AI, stroke prognosis

The study’s design was straightforward but rigorous. The researchers collected clinical data and contrast-enhanced cranial MRI images from all patients admitted with intracranial tuberculosis between January 2018 and March 2026. Each patient underwent follow-up lasting at least 12 months, after which outcomes were graded using the modified Rankin Scale, a standard clinical measure of functional disability. Patients scoring 0 to 2, meaning little to no disability, formed the favorable prognosis group of 67 individuals, while those scoring 3 to 6, ranging from moderate disability to death, formed the poor prognosis group of 52 patients.

Contrast-enhanced MRI was central to the investigation because it reveals pathological changes that plain CT and non-contrast imaging often miss. Gadolinium-based contrast agents leak across disrupted blood-brain barriers, highlighting thickened, inflamed meninges, tuberculomas, abscesses, and the characteristic basal enhancement pattern of tuberculous meningitis. This technique allowed the team to classify patients into imaging subtypes and to document complications such as cerebral infarction, hydrocephalus, and cerebral arteritis with far greater sensitivity than conventional approaches.

When the two prognosis groups were compared, striking differences emerged. Patients in the poor prognosis group were older and more frequently male. They more often presented with meningeal-type or mixed-type intracranial tuberculosis rather than the parenchymal form, and they showed significantly higher rates of meningeal thickening, involvement of the basal and pericallosal cisterns, multi-site meningeal involvement, acute cerebral infarction, hydrocephalus, and cerebral arteritis. Conversely, parenchymal-type disease and tuberculomas were less common in the poor outcome group, suggesting that disease confined to brain tissue with discrete granulomas may carry a better outlook than diffuse meningeal inflammation.

To move beyond simple associations, the researchers performed multivariate logistic regression, a statistical technique that isolates the independent contribution of each variable while controlling for all others. Three factors emerged as independent risk factors for poor long-term prognosis: age, acute cerebral infarction, and hydrocephalus. This finding is clinically meaningful because it separates true prognostic drivers from markers that merely travel alongside them. Meningeal thickening and arteritis, for example, were more common in poor-outcome patients but did not retain independent predictive value once infarction and hydrocephalus were accounted for.

The predictive model built from these three variables performed impressively well. Evaluated with receiver operating characteristic analysis, it achieved an area under the curve of 0.861, sensitivity of 70.1 percent, specificity of 89.6 percent, and overall accuracy of 80.7 percent. In practical terms, the model correctly identified nearly nine out of ten patients who would ultimately do well, while capturing seven out of ten of those destined for poor outcomes. An AUC above 0.85 is generally considered strong discrimination for a clinical prediction model, particularly one built on routinely available imaging and demographic data.

Each of the three predictors tells a coherent biological story. Older patients have less physiological reserve, more comorbidities, and blunted immune responses that impair clearance of infection and repair of tissue damage. Acute cerebral infarction in tuberculous meningitis typically results from inflammatory occlusion of small perforating arteries at the base of the brain, where exudate accumulates in the subarachnoid space and triggers vasculitis. Once brain tissue is lost to infarction, recovery is limited, and the infarct itself serves as a proxy for both disease severity and vascular involvement. Hydrocephalus, meanwhile, arises when inflammatory debris obstructs cerebrospinal fluid flow through the ventricular system or impairs its resorption at the arachnoid granulations, raising intracranial pressure and compressing neural tissue.

The Evans index, a ratio comparing the width of the frontal horns of the lateral ventricles to the maximal internal diameter of the skull, was among the imaging variables recorded, providing a quantitative measure of ventricular enlargement. Its inclusion alongside direct assessments of hydrocephalus reflects the study’s effort to capture both qualitative radiological judgments and reproducible morphometric markers. Similarly, the initial Glasgow Coma Scale score was documented for each patient, anchoring the clinical assessment at admission and allowing the investigators to account for baseline neurological status.

The implications for clinical practice are substantial. Patients with intracranial tuberculosis who present with advanced age, evidence of acute infarction on contrast-enhanced MRI, or ventricular enlargement can now be flagged early as high risk, prompting intensified monitoring, earlier consideration of surgical intervention for hydrocephalus such as ventriculoperitoneal shunting, and closer attention to antitubercular therapy optimization. Conversely, patients with parenchymal-type disease and tuberculomas, who showed more favorable outcomes in this cohort, may be candidates for less intensive follow-up protocols, though the authors caution that individualized assessment remains essential.

Limitations of the study are worth noting. As a single-center retrospective analysis, its findings require validation in larger, multicenter cohorts before widespread adoption of the risk model. The retrospective design also means that imaging protocols and clinical management may have varied over the eight-year enrollment period. Nevertheless, the study demonstrates that contrast-enhanced cranial MRI, already a mainstay of diagnosis in intracranial tuberculosis, can be repurposed as a prognostic tool, transforming a routine diagnostic scan into a roadmap for risk stratification and early intervention. As tuberculosis continues to pose a global burden, particularly in regions with limited neurosurgical resources, simple imaging-based predictors of outcome could help clinicians allocate intensive care where it matters most.

Subject of Research: Risk stratification of intracranial tuberculosis patients using contrast-enhanced MRI predictors of long-term prognosis

Article Title: Risk stratification in intracranial tuberculosis patients based on contrast-enhanced MRI

Article References: Wang, Y.-J., Qiu, X.-W., Wang, A.-L., Hu, Y.-N., Li, W.-Q., & Huang, X.-S. (2026). Risk stratification in intracranial tuberculosis patients based on contrast-enhanced MRI. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14479-w

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14479-w

Keywords: intracranial tuberculosis, contrast-enhanced MRI, hydrocephalus, cerebral infarction, tuberculous meningitis, prognosis, risk stratification, neuroradiology, modified Rankin Scale, cerebral arteritis, BMC Infectious Diseases, Risk

The Oahu experience offers a rare window into how a prehospital triage policy behaves when the usual confounders of real-world stroke systems are largely removed. In most metropolitan regions, patients with suspected large vessel occlusion can be routed to any of several thrombectomy-capable hospitals, each with its own workflows, staffing patterns, and activation criteria. That heterogeneity makes it difficult to attribute changes in treatment times to the bypass policy itself rather than to differences between receiving centers. On Oahu, by contrast, a single comprehensive stroke center receives all endovascular candidates, decisions about mechanical thrombectomy are made by one unified team of stroke neurologists and neurointerventionalists, and a single EMS agency handles prehospital transport for the entire island of roughly one million residents within 597 square miles. This closed-loop structure means that any shift in onset-to-door time observed after August 1, 2019—the date the bypass protocol took effect island-wide—can be interpreted with considerably more confidence than in open systems where patient migration between competing centers muddies the analysis.

The mechanics of the protocol deserve attention because they illustrate how prehospital stroke science is translated into dispatch-level practice. Under the Oahu scheme, EMS providers administer the Cincinnati Stroke Triage Assessment Tool, a brief field examination designed to discriminate cortical large vessel occlusions from smaller infarcts that do not benefit from thrombectomy. Patients scoring two or higher are classified as bypass-positive and transported directly past the nearest community hospital to the comprehensive stroke center, even when that nearest hospital would otherwise have been only minutes away. Before the policy change, standard EMS doctrine directed transport to the closest emergency department regardless of stroke severity, with exceptions reserved for major trauma or provider discretion. The consequence of the old doctrine was predictable: a patient with a disabling LVO would arrive at a community hospital, undergo initial evaluation and imaging, be recognized as needing endovascular therapy, and then require a second ambulance transfer to the comprehensive stroke center—consuming the very hours during which penumbral brain tissue remains salvageable.

The five-fold decline in interfacility transfers for endovascular therapy, from 55.9 percent of cases before implementation to 11.6 percent afterward, is arguably the most operationally meaningful finding in the study. Interfacility transfer is the single largest source of avoidable delay in stroke systems of care, because it compounds two ambulance trips, two emergency department evaluations, two imaging workflows, and two handoffs into a single treatment timeline. National quality registries have repeatedly shown that patients who require a drip-and-ship transfer to reach a thrombectomy-capable center lose substantial time compared with those who arrive directly. By collapsing that two-step journey into one, the Oahu protocol eliminated the dominant structural delay in the island’s treatment chain, and the 66-minute sustained reduction in onset-to-door time measured by the interrupted time series analysis is the direct arithmetic consequence of that collapse.

The interrupted time series design strengthens the causal interpretation in ways that a simple before-and-after comparison cannot. By grouping treatment times into quarterly averages and modeling both the change in level and any change in slope after implementation, the analysis distinguishes an abrupt policy effect from a gradual secular trend. The Durbin-Watson assessment for autocorrelation further guards against the possibility that the observed drop merely reflects a pre-existing downward drift in treatment times that happened to coincide with the protocol launch. The finding of a sustained level shift with no change in temporal trend indicates that the bypass produced a discrete, durable improvement rather than accelerating an ongoing improvement that would have occurred anyway.

Equally important is what did not get worse. A persistent concern with bypass protocols is that routing the sickest patients past community hospitals might delay thrombolysis for patients who turn out not to have an LVO, or who would have benefited from rapid intravenous thrombolytic administration at the nearest facility. The Oahu data showed no significant change in onset-to-thrombolytic time after implementation, which suggests that the field screening tool and the routing logic did not systematically penalize patients who still needed intravenous reperfusion therapy. This finding aligns with the broader literature on LVO scales, which generally accept a modest trade-off in thrombolysis timing in exchange for large gains in thrombectomy timing, but it is reassuring to see that trade-off was not required on Oahu.

The relationship between time and outcome that emerged from the multivariate modeling reinforces why these minutes matter. Every additional 30 minutes of delay from symptom onset to successful reperfusion increased the odds of a worse 90-day modified Rankin Scale score by six percent, an effect consistent in direction and magnitude with the time-to-treatment gradients reported in randomized thrombectomy trials and pooled patient-level meta-analyses. The biology underlying this gradient is well characterized: each minute of persistent arterial occlusion converts salvageable penumbral tissue into irreversibly infarcted core, so the functional benefit of reperfusion decays continuously with time. A 41-minute reduction in onset-to-reperfusion time, even one that fell short of conventional statistical significance in this cohort, would therefore be expected to translate into a modest but real shift in the distribution of disability—provided the cohort is large enough and the time savings reach the patients who stand to gain the most.

That last caveat is where the Oahu results become most instructive about the limits of systems interventions. Despite the substantial and sustained reduction in treatment times, the post-bypass era was not associated with a statistically significant improvement in good 90-day outcomes, defined as modified Rankin Scale scores of zero to two, and the adjusted odds ratios for both good outcomes and the ordinal shift in disability hovered near unity. There was, however, a suggestive trend toward more excellent outcomes—scores of zero or one—which rose from 23.5 percent to 34.5 percent in unadjusted comparison and retained a positive but non-significant adjusted association. The most plausible reading is that the study was underpowered to detect the modest outcome benefit that a 41-minute time saving would be expected to produce. With 102 patients in the pre-bypass era and 249 in the post-bypass era, and with functional outcome influenced by many factors beyond timing—age, baseline stroke severity, clot location, reperfusion success, and symptomatic hemorrhage among them—the signal from a time saving of this size may simply be diluted below the threshold of detectability.

Several other factors may also have blunted the observable outcome benefit. The institutional criteria for mechanical thrombectomy during the study period required a baseline modified Rankin Scale of zero to two, an NIH Stroke Scale score of at least six, and an ASPECTS score between six and ten, which restricts the treated population to patients with moderate to severe anterior circulation strokes and reasonable pretreatment function. Patients at the milder end of the spectrum, who might have gained the most from faster reperfusion in absolute terms of preserved independence, were not eligible for the procedure at all. Additionally, the bypass protocol changed not only where patients went but who arrived at the comprehensive stroke center; if the post-bypass cohort included more severe or more bypass-positive patients by design, case-mix shifts could offset some of the timing gains in the adjusted models. The investigators addressed this by adjusting for age, baseline NIHSS, clot location, reperfusion status, and symptomatic hemorrhage, but residual confounding in a retrospective design is inevitable.

The comparison with RACECAT and TRIAGE-STROKE, the two randomized trials of prehospital bypass strategies, adds an important layer of interpretation. Both trials confirmed that direct transport to thrombectomy-capable centers shortens onset-to-puncture times, yet neither demonstrated improved functional outcomes, mirroring the Oahu pattern of time savings without proven outcome benefit. The convergence of these findings across a randomized European trial, a randomized Catalan trial, and a natural experiment in a closed island system suggests that the time-outcome relationship, while real at the individual patient level, is difficult to demonstrate at the system level when the time savings are measured in tens of minutes rather than hours. It also raises the possibility that the benefit of bypass is heterogeneous: patients with the longest prehospital delays, the largest salvageable penumbras, or the most accessible occlusions may benefit substantially, while the cohort average dilutes that benefit.

For stroke systems planners, the practical lessons are nonetheless concrete. First, a simple, validated field tool administered by a single EMS agency can reliably redirect LVO candidates and produce large, durable reductions in door time without harming thrombolysis delivery. Second, the magnitude of benefit from bypass depends heavily on the baseline system: in regions where interfacility transfer rates are as high as the 55.9 percent seen on Oahu before implementation, the headroom for improvement is enormous, whereas systems that already route most patients directly may see smaller gains. Third, geography matters. Oahu’s compact, single-center catchment meant that bypass added relatively little transport time for most patients; in sprawling regions where the nearest thrombectomy-capable center is far away, the calculus of bypass versus nearest-hospital-first becomes more complex and may favor drip-and-ship for some patients. Finally, the Oahu experience underscores that process metrics, while necessary, are not sufficient—demonstrating that a systems intervention improves the lives of stroke patients ultimately requires either larger cohorts, longer follow-up, or composite endpoints sensitive enough to capture the modest population-level shifts that faster reperfusion can deliver.

Subject of Research: Prehospital large vessel occlusion bypass protocol and its effect on endovascular stroke treatment times and outcomes

Article Title: Reducing onset-to-door times through the implementation of a prehospital large vessel occlusion bypass protocol: the Oahu experience

Article References: Sun, C.-H., Chun, I., Nakagawa, K., Brown, S., Tsappidi, S., Hui, F., Zhang, Y., Salem, R., Zhang, G., Galanis, D., & Koenig, M. (2026). Reducing onset-to-door times through the implementation of a prehospital large vessel occlusion bypass protocol: the Oahu experience. Frontiers in Stroke, 5, Article 1903852. https://doi.org/10.3389/fstro.2026.1903852

Image Credits: AI Generated

DOI: 10.3389/fstro.2026.1903852

Keywords: stroke, large vessel occlusion, endovascular thrombectomy, EMS bypass protocol, prehospital triage, onset-to-door time, reperfusion, comprehensive stroke center, Oahu, interrupted time series, modified Rankin Scale, mobile stroke units

Allostatic load is a concept introduced in the early 1990s to describe the wear and tear that chronic stress inflicts on the body. Sustained activation of neuroendocrine and autonomic systems, the physiological machinery of the stress response, gradually promotes hypertension, atherosclerosis, increased coagulability, and low-grade inflammation. Over time, this multisystem dysregulation leaves the body and brain more vulnerable to injury. Researchers have linked high allostatic load to cardiovascular disease, all-cause and cardiovascular mortality, and disability in the general population, yet relatively little work has examined it directly in the context of stroke itself.

That gap is what motivated a team led by Eva Birgitte Aamodt of Oslo University Hospital, working with colleagues at Houston Methodist and TIRR Memorial Hermann in Texas, to investigate whether allostatic load measured at hospitalization predicts outcomes after acute ischemic stroke. Their findings, published in Frontiers in Stroke, indicate that patients with higher allostatic load at admission face longer hospital stays, higher mortality, and greater dependency 90 days after their stroke.

The study drew on the Houston Methodist Registry of Neurological Endpoint Assessments among Patients with Ischemic and Hemorrhagic Stroke, known as REINAH, an observational registry spanning seven certified stroke centers in and around Houston. From this registry, the researchers included 4,103 patients with acute ischemic stroke. For a sub-cohort of 2,244 patients, 90-day functional outcomes were available through the modified Rankin Scale, a standard measure of post-stroke disability ranging from 0 to 6, with higher scores indicating greater disability.

To construct the allostatic load score, the researchers used ten routinely collected clinical parameters representing three physiological systems. The metabolic system was captured by body mass index, glycated hemoglobin, total cholesterol, triglycerides, and high-density lipoprotein cholesterol. The inflammatory system was represented by C-reactive protein and white blood cell count. The vascular system was captured by systolic and diastolic blood pressure and pulse. Each parameter was scored by quartiles, with a point assigned if the value fell in the highest-risk quartile, and the points were summed to yield a score from 0 to 10. A score of 4 or higher was considered high allostatic load, a threshold the researchers chose because of the heavy comorbidity burden typical of stroke populations. Notably, no neuroendocrine parameters, such as cortisol, were available, so the score reflects metabolic, inflammatory, and vascular dysregulation rather than the full four-system conceptualization of allostatic load.

The results were striking. Patients with high allostatic load spent an average of 8.69 days in the hospital compared with 6.61 days for those with moderate-low load. Mortality at 90 days was 8.17 percent in the high-load group versus 3.08 percent in the moderate-low group. Among patients with 90-day follow-up, 57.06 percent of those with high allostatic load were dependent, defined as a modified Rankin Scale score of 3 or higher including death, compared with 41.85 percent of those with moderate-low load. These associations persisted after statistical adjustment for age, sex, race, stroke severity measured with the National Institutes of Health Stroke Scale at 6 and 24 hours, reperfusion therapies, and medications. In the fully adjusted models, high allostatic load remained associated with mortality with an odds ratio of 2.90, and with dependency with an odds ratio of 1.64, indicating that the burden was not simply a proxy for stroke severity or age.

The researchers also examined which factors were independently associated with high allostatic load. Younger age, Black race, higher area deprivation index, being single, illegal drug use, diabetes mellitus, sepsis, higher Charlson comorbidity index, anticoagulation reversal therapy, antihypertensive therapy, and higher stroke severity at 6 and 24 hours all predicted high load. Conversely, being a woman, hypercholesterolemia, atrial fibrillation, anticoagulant therapy, intravenous tissue plasminogen activator treatment, and endovascular thrombectomy were associated with moderate-low load. The inverse relationship between age and allostatic load was unexpected and likely reflects a survivorship effect, with older adults carrying high physiological burden being underrepresented in the registry.

A key sensitivity analysis added an important nuance. Because C-reactive protein and white blood cell count may partly reflect the acute inflammatory response to the stroke itself rather than chronic physiological burden, the researchers repeated their analyses using an alternative eight-biomarker score excluding these inflammatory parameters. The association between allostatic load and 90-day mortality disappeared in these models, suggesting that the inflammatory components contributed substantially to the observed mortality link. By contrast, the association with functional dependency remained essentially unchanged, and the association with length of stay persisted in partially adjusted models. This pattern implies that the prognostic value of allostatic load reflects both chronic multisystem dysregulation and acute inflammatory responses, and that the score may be particularly informative for functional outcomes.

The biological interpretation is compelling. Elevated allostatic load in this study primarily reflected chronic cardiometabolic and inflammatory dysregulation, including elevated blood pressure, glycemia, lipid levels, and C-reactive protein. Such long-standing vascular and systemic burden could reduce cerebrovascular reserve, impair circulation, and diminish ischemic tolerance, predisposing individuals to larger infarcts and more severe neurological deficits. The finding that higher allostatic load was linked to higher stroke severity at both 6 and 24 hours is consistent with this framework, although the researchers caution that some score components were measured during acute hospitalization and may themselves have been influenced by the stroke, so a causal relationship cannot be established from this observational design.

The authors suggest that allostatic load may serve as a clinically accessible marker of biological resilience, helping identify patients at increased risk of poor post-stroke outcomes. If validated in future studies, it could support risk stratification and guide closer monitoring or more individualized post-stroke care, particularly for functional recovery. However, the study has limitations: the allostatic load index lacked neuroendocrine measures central to the original concept, complete-case analyses may have introduced selection bias, roughly half the cohort had 90-day functional data, and the study did not evaluate whether allostatic load provides incremental prognostic value beyond established predictors such as age and stroke severity using discrimination metrics. Future work incorporating pre-stroke measures of allostatic load and testing its added value in prospective models will be needed to determine whether this composite marker of cumulative stress can move from research into clinical decision making after stroke.

Subject of Research: Neuroscience

Article Title: Higher allostatic load at hospitalization is linked to worse outcome 90 days after stroke

Article References: Aamodt, E. B., Borei, K., Potter, T., & Vahidy, F. (2026). Higher allostatic load at hospitalization is linked to worse outcome 90 days after stroke. Frontiers in Stroke, 5, Article 1847419. https://doi.org/10.3389/fstro.2026.1847419

Image Credits: AI Generated

DOI: 10.3389/fstro.2026.1847419

Keywords: allostatic load, stroke, ischemic stroke, mortality, dependency, length of stay, stress, modified Rankin Scale, Higher, allostatic, load, hospitalization

Researchers at Inselspital, University Hospital Bern, in Switzerland, analyzed a consecutive series of 1,764 patients with acute anterior circulation ischemic stroke who underwent EVT, with or without intravenous thrombolysis, between February 2015 and March 2023. The data came from the prospectively maintained Swiss Stroke Registry, and nearly half of the patients, 48.4 percent, were women. The cohort had a median age of 76 years, making it one of the largest contemporary single-center datasets of its kind. All patients were treated at a comprehensive stroke center or transferred there through an established drip-and-ship model from referring hospitals, ensuring a standardized diagnostic and therapeutic pathway for everyone in the analysis.

The baseline picture that emerged was strikingly different between the sexes. Women were considerably older than men when they arrived, with a median age of 79.4 years compared with 73.3 years, and they more often carried atrial fibrillation, the irregular heart rhythm that predisposes to clots traveling from the heart to the brain, and chronic kidney disease. Men, by contrast, more frequently had coronary heart disease, heart failure, diabetes mellitus, and a current smoking habit. These divergent risk profiles translated directly into different stroke mechanisms: cardioembolic stroke, in which a clot originates in the heart, accounted for 46.3 percent of strokes in women versus 39.1 percent in men, whereas large artery atherosclerosis, the cholesterol-driven narrowing and rupture of vessel walls, was found in 18.1 percent of men against just 11.3 percent of women.

The pathophysiology behind this pattern is plausible, the authors argue. Advanced age and atrial fibrillation favor the formation of thrombi within the atria, which then embolize to the cerebral circulation, explaining the cardioembolic predominance in women. A heavier atherosclerotic burden in men, driven by smoking, diabetes, and coronary disease, points instead toward the artery-to-artery mechanism of large vessel atherosclerosis. Chronic kidney disease, more prevalent among women in the cohort, is itself an established cerebrovascular risk factor through chronic inflammation, endothelial dysfunction, and a prothrombotic state, and its higher prevalence may partly reflect the women’s older age.

Interestingly, when it came to the logistics of acute care, the sexes were treated almost identically. The time from last known well to hospital arrival, from door to imaging, from imaging to groin puncture, and from door to groin puncture did not differ significantly between women and men. The only workflow difference was a slightly shorter groin-puncture-to-reperfusion time in women, a gap of less than two minutes that the investigators considered unlikely to be clinically meaningful. This stands in contrast to numerous earlier studies reporting longer prehospital delays and lower rates of timely reperfusion therapy in women, disparities the Bern team attributes to well-established regional stroke pathways and standardized emergency medical services triage.

Treatment strategies did diverge in some notable ways. Men more often received bridging therapy, meaning intravenous thrombolysis before thrombectomy, at 40.8 percent versus 34.7 percent, and they more frequently underwent intracranial and extracranial stenting, procedures typically needed when atherosclerotic plaque must be propped open. These differences almost certainly reflect the higher burden of large artery disease in men rather than any preferential triage. Crucially, the core technical aspects of the procedure were equivalent: thrombectomy technique, anesthesia strategy, device selection, number of stent retriever passes, and procedural complication rates were all similar, and successful reperfusion, defined as a modified Thrombolysis in Cerebral Infarction score of 2b or higher, was achieved in 86.2 percent of all patients with no significant difference between the sexes.

Here is where the story takes its most important turn. In the raw, unadjusted data, women clearly did worse. At three months, only 37.5 percent of women had achieved a favorable functional outcome, defined as a modified Rankin Scale score of 2 or less, compared with 47.6 percent of men. Excellent outcome, a Rankin score of 1 or less, was reached by 25.6 percent of women versus 31.4 percent of men. Three-month mortality was 31.9 percent in women against 24.9 percent in men, and women were less often discharged home or to inpatient rehabilitation.

But once the researchers adjusted for the factors that actually drive recovery, including age, baseline stroke severity on the National Institutes of Health Stroke Scale, pre-stroke disability, atrial fibrillation, coronary heart disease, chronic kidney disease, occlusion site, bridging therapy, procedure duration, and calendar period, the sex gap vanished. Female sex was not independently associated with successful reperfusion, favorable outcome, excellent outcome, or mortality, with adjusted odds ratios hovering near unity and confidence intervals crossing one in every analysis. In other words, women did not do worse because they were women; they did worse because they were, on average, six years older, more disabled before their stroke, and sicker overall. Age, pre-stroke functional status, stroke severity, and comorbidity burden were far stronger predictors of outcome than sex itself.

One nuance did survive the statistical gauntlet. The team detected a sex-by-age interaction for favorable functional outcome, with the association between sex and outcome varying according to age. This exploratory finding requires confirmation in independent cohorts, and no such interaction was seen for reperfusion success, excellent outcome, or mortality, nor for effect modification by stroke etiology or bridging therapy. The authors also caution that their retrospective, single-center design limits generalizability, that the eight-year study window spanned evolving EVT techniques, and that factors such as frailty, hormonal status, clot composition, living situation, socioeconomic status, and access to rehabilitation were not captured, leaving room for residual confounding.

The clinical implications are nonetheless clear and, in their own way, reassuring. The findings support current guideline recommendations that sex alone should not influence patient selection for thrombectomy; decisions should rest on established clinical and imaging criteria applied equally to everyone. At the same time, the sharply different risk profiles argue for sex-specific prevention: intensified detection and management of atrial fibrillation in women, and aggressive control of atherosclerotic risk factors, smoking cessation, diabetes management, and lipid lowering, in men. The research team calls for future multicenter studies with predefined sex-specific analyses, better separation of sex from gender-related factors, and routine representation of women in clinical trials. For now, the message for patients and physicians alike is simple: when a large vessel occlusion strikes, the catheter lab treats both sexes with equal technical success, and it is age, disability, and comorbidity, not sex, that shape the road to recovery.

Subject of Research: Sex differences in vascular risk factors, stroke etiology, treatment characteristics, and outcomes after endovascular treatment for anterior circulation ischemic stroke

Article Title: Sex differences in risk factors, stroke etiology, treatment characteristics, and outcomes after endovascular treatment for anterior circulation ischemic stroke

Article References: Peycheva, M., Berger, C., Costa, M., Siegenthaler, L., Huber, F., Rizzo, I., Krasteva, M., Beyeler, M., Bremova-Ertl, T., Slavova, N., Mordasini, P., Umarova, R. M., Bücke, P., Antonenko, K., Hoffmann, A., Pilgram-Pastor, S., & Heldner, M. R. (2026). Sex differences in risk factors, stroke etiology, treatment characteristics, and outcomes after endovascular treatment for anterior circulation ischemic stroke. Frontiers in Stroke, 5, Article 1946990. https://doi.org/10.3389/fstro.2026.1946990

Image Credits: AI Generated

DOI: 10.3389/fstro.2026.1946990

Keywords: acute ischemic stroke, endovascular treatment, thrombectomy, sex differences, stroke etiology, cardioembolic stroke, large artery atherosclerosis, reperfusion, modified Rankin Scale, atrial fibrillation, stroke outcomes, Swiss Stroke Registry

The study’s design is what sets it apart from much of the existing literature. Most previous estimates of postoperative infarction and edema have come from retrospective chart reviews, in which radiologists examined scans ordered for clinical reasons rather than for research. That approach risks missing injuries that never produce obvious symptoms. In this prospective observational study, the Chinese team enrolled patients before their operations and mandated a strict imaging schedule: an early MRI within 72 hours of surgery, followed by repeat scans on postoperative days 7, 14 and 28. This serial protocol allowed the investigators to watch injuries evolve in real time, distinguishing fresh infarcts from older changes, tracking the waxing and waning of brain swelling, and capturing microhemorrhages that a single routine scan could easily overlook. Neurological function was then formally assessed at day 28 using the modified Rankin Scale, a standard clinical measure in which scores of 2 or higher indicate disability that interferes with independent daily life.

The headline result concerns stroke. Postoperative infarction, dead brain tissue caused by interrupted blood supply, appeared in 14 of the 64 patients, an incidence of 21.9 percent. Strikingly, every one of these infarcts was localized to the same trio of deep brain regions: the basal ganglia, the thalamus and the insula. These are not random locations. They are the territories supplied by small, deeply penetrating arteries, the lenticulostriate vessels and their counterparts, which branch directly off major arteries such as the middle cerebral artery and run upward through the surgical corridor to reach the tumor. When gliomas sit in or near these deep gray-matter structures, the dissection plane can pass within millimeters of these fragile perforating vessels. The study’s anatomical pattern therefore points to a mechanical mechanism: perforating arteries are being stretched, cauterized, or sacrificed during resection, and the deep nuclei they supply pay the price.

When the researchers searched for risk factors, one variable stood out with statistical force. Intraoperative blood loss of 300 milliliters or more was independently associated with postoperative infarction, with an odds ratio of 4.62 and a p-value of 0.035, meaning the association was unlikely to be due to chance. The connection makes physiological sense. Heavy bleeding during surgery can drop blood pressure, reduce perfusion through small vessels, force more aggressive coagulation of bleeding points, and obscure the surgical field so that fine perforators are harder to identify and preserve. Blood loss, in this framing, is not merely a marker of a bloody operation; it is a proxy for hemodynamic stress and hemostatic manipulation throughout the case. The authors’ conclusion is direct: meticulous intraoperative hemostatic management, careful control of bleeding from the first incision to the final closure, is essential to prevent postoperative infarction and the disability that can follow.

The second major finding concerned microhemorrhage, tiny punctate bleeds visible on susceptibility-weighted MRI sequences. These were remarkably common, detected in 53.8 percent of patients, more than half of the cohort. Microhemorrhages are often dismissed as clinically silent, and in many contexts they are. But their prevalence here suggests that blood-brain barrier disruption and capillary trauma extend far beyond the visible margins of the resection cavity. Whether these microbleeds accumulate into lasting cognitive consequences, as they appear to do after traumatic brain injury and in cerebral amyloid angiopathy, remains an open question that this study was not designed to answer. Still, their frequency reframes glioma surgery: the zone of injury is not a sharp line at the tumor border but a gradient of vascular damage that radiates outward into apparently normal brain.

Perhaps the most conceptually interesting result involves edema, the swelling that accompanies virtually every brain tumor and every brain operation. Peritumoral edema was present in all 64 patients, but the serial scans revealed that it came in two distinct flavors. In 42 patients, the swelling was residual tumor-associated edema, the vasogenic swelling driven by the tumor’s leaky vessels and inflammatory secretions, which shrank over time as the mass was removed. In 22 patients, however, the team identified de novo surgery-induced edema, swelling that appeared or expanded after the operation in areas where the tumor had driven the original fluid accumulation. The two patterns moved in opposite directions on serial imaging: the average volume of tumor-associated edema decreased over the four weeks of follow-up, while surgery-induced edema increased. This distinction matters clinically, because the two types of swelling can mimic one another on a single scan, and misreading postoperative edema as residual tumor, or vice versa, can lead to premature decisions about additional treatment.

The neurological stakes of all this radiological injury became clear in the outcome data. Of the 53 patients who completed the day-28 functional assessment, 13 had developed disability, scoring 2 or higher on the modified Rankin Scale. That is roughly one in four of those assessed, a sobering figure for operations performed with curative or life-extending intent. Two factors independently predicted poor outcome: higher intraoperative blood loss, with an odds ratio of 8.88 and a p-value of 0.013, and postoperative infarction, with an odds ratio of 6.33 and a p-value of 0.031. The blood loss association was the stronger of the two, reinforcing the study’s central message that what happens inside the operating room, particularly the management of bleeding, echoes directly into the patient’s functional recovery a month later.

These findings land in a field that has long been pulled in two directions. On one side stands the well-documented survival benefit of maximal resection: large studies have repeatedly shown that removing more contrast-enhancing tumor, and even supratotal resection extending beyond the MRI-visible margin, is associated with longer survival in glioblastoma and in lower-grade gliomas. On the other side is the growing recognition that the deep perforating arteries coursing through glioma territory are vulnerable, and that strokes after glioma surgery are neither rare nor benign. Earlier retrospective work, including studies from European groups, has reported postoperative ischemia rates ranging from a few percent to more than 20 percent depending on tumor location and detection methods, with insular and deep-seated tumors consistently flagged as high risk. The new prospective data confirm those signals with a rigor that retrospective series cannot match, and they add the temporal dimension, showing how infarcts, edema and microbleeds each follow their own trajectory in the first postoperative month.

The practical implications are already taking shape. For surgeons, the study argues for treating blood loss as a modifiable target rather than an unavoidable byproduct of tumor resection: aggressive early hemostasis, careful preservation of perforating vessels identified on preoperative tractography and angiography, and perhaps a lower threshold for staged or subtotal resection when a critical perforator is at risk. For oncologists and radiologists, the two-pattern model of edema provides a framework for interpreting postoperative scans, suggesting that serial imaging rather than a single early study may be needed to separate resolving tumor edema from progressive surgical swelling. For patients and families, the numbers offer a realistic picture of the risk-benefit calculus: in this cohort, roughly one in five patients sustained a radiological stroke, and one in four assessed patients had measurable disability at one month, but the study also identifies a concrete, actionable lever, intraoperative hemostatic management, that could shift those odds. Larger multicenter prospective studies will be needed to confirm the risk factors and to test whether protocol changes in the operating room actually reduce disability, but this work marks an important step toward making glioma surgery not only more complete, but also more gentle on the brain that surrounds the tumor.

Subject of Research: Radiological features of surgical brain injury and neurological outcomes after glioma resection

Article Title: Radiological features of peritumoral brain injury and neurological outcomes after glioma surgery: a prospective observational study

Article References: Cheng, J., Chen, Z., Li, D., Guo, Z., Yang, Y., Luo, X., Zhang, J., Chen, Y., Jiang, X., Lin, F., Zhao, Q., Zhou, Z., & Chen, Z. (2026). Radiological features of peritumoral brain injury and neurological outcomes after glioma surgery: a prospective observational study. Journal of Neuro-Oncology, 180(1), Article 17. https://doi.org/10.1007/s11060-026-05828-5

Image Credits: AI Generated

DOI: 10.1007/s11060-026-05828-5

Keywords: glioma surgery, surgical brain injury, brain infarction, brain edema, microhemorrhage, intraoperative blood loss, modified Rankin Scale, MRI, neurosurgery, perforating arteries, neurological outcomes, prospective observational study

The research, led by Xinya Li and colleagues including Anxin Wang, drew on the Third China National Stroke Registry, one of the largest and most rigorously maintained stroke databases in the world. Between 2015 and 2018, the registry enrolled consecutive adult patients admitted to participating hospitals with a diagnosis of ischemic stroke, in which a blood clot blocks flow to part of the brain, or transient ischemic attack, a temporary interruption of blood supply that often precedes a full stroke. From this population, the investigators identified 2,859 patients who left the hospital with a prescription for either amlodipine or nifedipine and who could be followed for five years afterward.

The question the team posed was deceptively simple: did patients taking one drug fare better than patients taking the other? But answering it in an observational setting, where doctors choose medications rather than a computer randomizing them, requires sophisticated statistical machinery. The researchers’ primary yardstick was the modified Rankin Scale, or mRS, a standard clinical tool that grades functional outcomes after stroke on a spectrum from zero, meaning no symptoms at all, to six, indicating death. Rather than collapsing this scale into crude categories, the team analyzed the full distribution of scores using ordinal logistic regression, a method that preserves the ordered nature of disability levels and yields an odds ratio describing the odds of being at a better rather than a worse point on the scale.

Because patients prescribed amlodipine might differ systematically from those given nifedipine, in age, sex, body mass index, blood pressure on admission, or timing of their stroke, the researchers applied inverse probability of treatment weighting, a technique that statistically reweights the two groups to mimic the balance achieved in a randomized trial. After this adjustment, the analytic cohort comprised 1,847 patients on amlodipine and 1,058 on nifedipine, with baseline characteristics aligned across the two groups. The models also adjusted for age, gender, body mass index, admission systolic blood pressure, and the date of symptom onset, guarding against confounding from calendar-time changes in stroke care.

The results pointed in one direction. Patients discharged on amlodipine showed significantly better functional outcomes at five years than those on nifedipine, with an odds ratio of 0.76 for worse mRS scores, a 95 percent confidence interval of 0.65 to 0.89, and a p-value below 0.001. Put more concretely, 51.76 percent of amlodipine users, 956 patients, had at least some residual disability or worse, an mRS score above zero, at five years, compared with 59.74 percent of nifedipine users, 632 patients. The corresponding odds ratio of 0.71, with a confidence interval of 0.61 to 0.83, indicates that the odds of avoiding disability were meaningfully higher in the amlodipine group. Sensitivity analyses, which test whether the findings survive alternative statistical assumptions, produced consistent results throughout.

What could explain such a divergence between two drugs that lower blood pressure through the same basic mechanism? Calcium channel blockers work by blocking L-type calcium channels in vascular smooth muscle, preventing calcium ions from entering these cells and thereby relaxing arterial walls. Nifedipine is a first-generation dihydropyridine with a short half-life in its immediate-release form, producing rapid vasodilation that can trigger reflex activation of the sympathetic nervous system, surges of heart rate, and oscillating blood pressure. Amlodipine, by contrast, has a long half-life of roughly 30 to 50 hours, producing gradual, sustained vasodilation with minimal peak-to-trough fluctuation. For a brain already injured by ischemia, the stability of perfusion pressure may be critical; sharp swings in blood pressure can stress impaired cerebral autoregulation, the mechanism by which brain blood vessels maintain constant flow despite systemic changes. The authors note that these pharmacological differences, along with amlodipine’s longer duration of action and smoother pharmacokinetic profile, could plausibly underlie the observed advantage, though the study design cannot prove causation.

The stakes of this question are enormous. Stroke remains a leading cause of death and long-term disability worldwide, and China bears a particularly heavy burden, with ischemic stroke accounting for the majority of the roughly four million new strokes recorded there each year. Secondary prevention after a stroke or TIA hinges on controlling vascular risk factors, and blood pressure management is the single most powerful modifiable lever. Because amlodipine and nifedipine are among the most commonly prescribed antihypertensives for these patients, and because they are often treated as clinically equivalent members of the same drug class, even a modest real difference in five-year functional outcomes would translate into substantial population-level effects if prescribing patterns shifted toward the better-performing agent.

The authors are careful to frame their findings as hypothesis-generating rather than practice-changing. As an observational study, it inherits the inherent limitations of registry data: physicians chose which drug to prescribe, and despite the statistical balancing achieved through weighting, unmeasured differences between the groups could still have influenced outcomes. The exclusive reliance on registry records limits the granularity of clinical information available, and the loss to follow-up at five years was relatively high, a common challenge in long-term cohort studies that can bias results if attrition differs between groups. These caveats do not erase the signal, which was robust across sensitivity analyses, but they mean the findings stop short of the evidentiary standard that typically guides prescribing decisions.

The path forward, the researchers argue, runs through randomized controlled trials, in which patients with ischemic stroke or TIA would be assigned by chance to amlodipine or nifedipine and followed prospectively. Such trials would eliminate the confounding that shadows any observational comparison and could also probe intermediate mechanisms, including ambulatory blood pressure variability, sympathetic activation, and markers of cerebral small-vessel health. Until then, the study stands as a striking reminder that drugs within the same class are not interchangeable, and that the quiet, long-acting pharmacology of amlodipine may offer stroke survivors something nifedipine does not: a steadier road to recovery measured not in days or months, but in the fullness of five years of life after the brain has been injured.

Subject of Research: Comparative effectiveness of amlodipine versus nifedipine at discharge after ischemic stroke or transient ischemic attack

Article Title: Comparative effectiveness of amlodipine versus nifedipine prescribed at discharge in patients with ischemic stroke or transient ischemic attack: A nationwide 5-year follow-up registry study

Article References: Li, X., Xia, X., Gao, M., Xu, Q., Zhang, Y., Jing, J., Zhai, Y., Meng, X., & Wang, A. (2026). Comparative effectiveness of amlodipine versus nifedipine prescribed at discharge in patients with ischemic stroke or transient ischemic attack: A nationwide 5-year follow-up registry study. PLOS Medicine, 23(10), e1005277. https://doi.org/10.1371/journal.pmed.1005277

Image Credits: AI Generated

DOI: 10.1371/journal.pmed.1005277

Keywords: amlodipine, nifedipine, calcium channel blockers, ischemic stroke, transient ischemic attack, blood pressure, functional outcome, modified Rankin Scale, stroke registry, secondary prevention, pharmacology, observational study

Branch atheromatous disease, often abbreviated as BAD, is a distinct and clinically consequential subtype of acute ischemic stroke, accounting for roughly 9 to 20 percent of cases. First described by neurologist Louis Caplan in 1989, it involves atherosclerotic disease at the origin of penetrating arteries, the small deep vessels that branch off major cerebral arteries such as the middle cerebral artery and the basilar artery. This mechanism differs fundamentally from lacunar infarction caused by lipohyalinosis, and BAD is not well captured by the conventional TOAST classification system that has long organized ischemic stroke subtypes. With advances in magnetic resonance imaging, BAD is increasingly recognized as a single subcortical infarction extending along a perforator territory without severe stenosis of the parent artery.

What makes BAD so clinically troubling is its tendency toward early neurological deterioration, a phenomenon in which patients who initially present with mild deficits suddenly worsen, sometimes dramatically, within hours or days of onset. More than 30 percent of patients with BAD remain disabled at follow-up, a striking figure given that many arrive at the hospital with only minor symptoms. Paradoxically, the annual risk of recurrent stroke in BAD is relatively low, at less than 3.8 percent. This high disability, low recurrence profile suggests that the most meaningful treatment goal in this population is preventing early deterioration and improving functional outcome, rather than preventing recurrent ischemic events. Yet the mechanisms driving deterioration, including perforator hypoperfusion, local thrombosis, and inflammation, remain incompletely understood, and no guideline-endorsed therapy specifically addresses this subtype. Intravenous alteplase has not consistently prevented deterioration, and most patients lack a target suitable for mechanical thrombectomy.

Into this therapeutic vacuum stepped tirofiban, a reversible antagonist of the glycoprotein IIb/IIIa receptor on platelets. By blocking this receptor, tirofiban rapidly and potently inhibits platelet aggregation, the cellular process at the heart of clot formation. Prior randomized trials had suggested that tirofiban could safely improve outcomes in select acute ischemic stroke populations, including patients with disabling non-cardioembolic stroke and those receiving it as an adjunct after intravenous thrombolysis or endovascular treatment. On the strength of this indirect evidence, clinicians increasingly administered tirofiban empirically to patients with BAD-related stroke, despite the absence of randomized data in that specific population. The BRANT trial was designed to test whether this common practice was actually justified.

The trial enrolled adults aged 18 to 75 years who presented within 48 hours of stroke onset and met strict MRI-based diagnostic criteria for BAD, defined as a single deep subcortical infarction in the territory of a lenticulostriate or paramedian pontine artery without more than 50 percent stenosis of the corresponding parent artery. Eligibility was confirmed through centralized imaging review, and patients with transient ischemic attack, cardioembolic sources, significant large-artery stenosis, or plans to receive thrombolysis or endovascular therapy were excluded. Between November 2023 and November 2025, 516 patients were randomly assigned in a 1:1 ratio to receive either intravenous tirofiban or guideline-based antiplatelet therapy. The tirofiban regimen consisted of a loading infusion of 0.4 micrograms per kilogram per minute for 30 minutes, followed by a maintenance infusion of 0.1 micrograms per kilogram per minute for 48 hours. The control group received either aspirin alone or aspirin plus clopidogrel for 48 hours, at the treating physician’s discretion. Although the trial was open-label, the statisticians, members of the independent clinical events committee, and outcome assessors were blinded to treatment allocation, protecting the integrity of the endpoint measurements.

The primary endpoint was an excellent functional outcome at 90 days, defined as a score of 0 or 1 on the modified Rankin Scale, which ranges from 0 for no symptoms to 6 for death. The results were unequivocally negative for superiority. At 90 days, 181 of 258 patients in the tirofiban group, or 70.2 percent, achieved an excellent functional outcome, compared with 178 of 255 patients, or 69.8 percent, in the standard antiplatelet group. The unadjusted risk ratio was 1.01 with a 95 percent confidence interval of 0.90 to 1.13, and the P value of 0.93 left no statistical ambiguity: the two strategies produced essentially identical outcomes. Adjusted analyses and per-protocol analyses yielded the same conclusion, and prespecified subgroup analyses across six baseline characteristics, including age, sex, hypertension, diabetes, stroke severity, and time from onset to randomization, found no hint of treatment effect heterogeneity.

Secondary outcomes told a similarly flat story. The rate of early neurological deterioration within seven days after randomization was 8.2 percent in the tirofiban group versus 6.3 percent in the control group, a difference that was not statistically significant and, if anything, numerically favored standard therapy. Ordinal modified Rankin Scale scores at 90 days, National Institutes of Health Stroke Scale scores at 7 and 90 days, and Barthel Index scores of daily independence at 90 days all showed no meaningful advantage for tirofiban. Recurrent ischemic events were rare in both arms, with ischemic stroke occurring in 1.9 percent of tirofiban patients and 1.6 percent of control patients within 90 days, consistent with the characteristically low recurrence risk of this stroke subtype.

On the safety side, major bleeding, defined by the PLATO criteria, was strikingly rare: zero events among 259 tirofiban-exposed patients with available safety assessments versus one event among 245 control patients, and no intracranial hemorrhage occurred in the tirofiban group. Rates of serious adverse events and all-cause death were similar between groups. However, the investigators caution that such a small number of bleeding events precludes any precise comparative safety conclusion, and the findings should not be interpreted as establishing equivalent safety between the two strategies.

The negative result takes on added significance when placed alongside the broader landscape of tirofiban research. The RESCUE BT2 trial, which enrolled patients with ischemic stroke without medium or large vessel occlusion, found that early tirofiban improved the proportion achieving excellent functional outcomes, but that cohort had a higher median baseline stroke severity and a mixture of etiologies, leaving the benefit for BAD specifically unclear. The TREND trial found tirofiban reduced early neurological deterioration in non-cardioembolic strokes, but 58 percent of its participants had large artery atherosclerosis or unknown etiology. Meanwhile, the STRATEGY trial, which also targeted BAD-related stroke, similarly found that tirofiban failed to reduce deterioration. One notable feature of BRANT is that 85.5 percent of control patients received dual antiplatelet therapy during the randomized period, a level of background platelet inhibition that may itself have attenuated any incremental benefit of adding tirofiban, since the control group may already have achieved substantial antithrombotic effect.

The trial’s authors are careful to frame what the result does and does not mean. Most patients were randomized relatively late after stroke onset, with a median time from onset to randomization of about 30 hours, and more than half of all early neurological deterioration events had already occurred before randomization, limiting any opportunity for tirofiban to intervene. Concomitant oral antiplatelet therapy was also prohibited during the tirofiban infusion, a design feature that distinguishes this regimen from other tirofiban-based strategies. The findings therefore do not constitute evidence against all tirofiban-based treatment approaches, nor do they establish equivalence between the two strategies. What they do establish, with the rigor of a well-powered randomized design, is that routine empirical use of intravenous tirofiban monotherapy cannot be recommended over standard oral antiplatelets for BAD-related stroke presenting within 48 hours of onset. Future trials, the investigators suggest, should explore whether ultra-early intervention, treatment of patients with active deterioration, or alternative pathophysiological targets might finally deliver the clinical benefit that has so far eluded this stubborn and disabling stroke subtype.

Subject of Research: A phase III randomized trial of intravenous tirofiban versus standard antiplatelet therapy for acute branch atheromatous disease-related ischemic stroke

Article Title: Tirofiban vs standard antiplatelet therapy in acute branch atheromatous disease-related stroke: a multicenter, randomized, open-label, blinded-endpoint, parallel-group, phase III clinical trial

Article References: Li, S., Hu, H., Zhang, D., Liu, B., Zhong, M., Wang, L., Yang, Q., Zhang, P., Zhao, W., Zhao, F., Tang, Y., Wang, X., Li, H., Chen, L., Chen, G., Wang, R., Dong, A., Zheng, Z., Wang, X., … Zhang, L. (2026). Tirofiban vs standard antiplatelet therapy in acute branch atheromatous disease-related stroke: a multicenter, randomized, open-label, blinded-endpoint, parallel-group, phase III clinical trial. The Lancet Regional Health – Western Pacific, 75, Article 101995. https://doi.org/10.1016/j.lanwpc.2026.101995

Image Credits: AI Generated

DOI: 10.1016/j.lanwpc.2026.101995

Keywords: tirofiban, branch atheromatous disease, ischemic stroke, antiplatelet therapy, early neurological deterioration, randomized controlled trial, glycoprotein IIb/IIIa inhibitor, perforating arteries, modified Rankin Scale, stroke outcomes, dual antiplatelet therapy, BRANT trial