Time Is Brain—Quantified

Emerging strategies for nerve repair and regeneration in ischemic stroke: neural stem cell therapy

Ischemic stroke is a major cause of mortality and disability worldwide, with limited treatment options available in clinical practice. The emergence of stem cell therapy has provided new hope to the field of stroke treatment via the restoration of brain neuron function. Exogenous neural stem cells are beneficial not only in cell replacement but also through the bystander effect. Neural stem cells regulate multiple physiological responses, including nerve repair, endogenous regeneration, immune function, and blood-brain barrier permeability, through the secretion of bioactive substances, including extracellular vesicles/exosomes. However, due to the complex microenvironment of ischemic cerebrovascular events and the low survival rate of neural stem cells following transplantation, limitations in the treatment effect remain unresolved. In this paper, we provide a detailed summary of the potential mechanisms of neural stem cell therapy for the treatment of ischemic stroke, review current neural stem cell therapeutic strategies and clinical trial results, and summarize the latest advancements in neural stem cell engineering to improve the survival rate of neural stem cells. We hope that this review could help provide insight into the therapeutic potential of neural stem cells and guide future scientific endeavors on neural stem cells.

Association of accelerated biological aging with brain volumes: A cross-sectional study

BACKGROUND

Multiple epidemiological studies have observed the connection between aging and brain volumes. The concept of accelerated biological aging (BA) is more powerful for observing the degree of aging of an individual than chronologic age (CA). The objective of this study is to explore the relationship between BA and brain volumes.

METHODS

BA was measured from clinical traits using two blood-chemistry algorithms, the Klemera-Doubal method (KDM) and the PhenoAge. The two age acceleration biomarkers were calculated by the residuals from regressing CA, termed "KDM-acceleration" and "PhenoAge-acceleration". Brain volumes were from brain magnetic resonance imaging (MRI) data. After adjustment for confounding factors, general linear regression models were used to examine associations between KDM-acceleration and PhenoAge-acceleration and brain volumes, respectively. Additionally, we stratified participants by sex, age, and the four quartiles of the Townsend Deprivation Index (TDI) for extra subgroup analysis.

RESULTS

14,725 participants with available information were enrolled. After full adjustment, we observed negative associations between KDM-acceleration and brain volumes, such as gray matter (β = -0.029), white matter (β = -0.021), gray and white matter (β = -0.026), and hippocampus (β = -0.011 for left and β = -0.014 for right). There were also negative associations between PhenoAge-acceleration and brain volumes, such as white matter (β = -0.008), gray and white matter (β = -0.010), thalamus (β = -0.012 for left and β = -0.012 for right). In the subgroup analysis stratified by sex, age, and the four quartiles of TDI, the association between KDM-acceleration and PhenoAge-acceleration and brain volumes still existed. In subgroup analyses, the variation in associations suggests that socioeconomic and biological factors may differentially influence brain aging.

CONCLUSIONS

Our research indicated that more advanced BA was associated with less brain tissue.

Effect of MR-guided perfusion imaging mismatch profiles within 6 h on endovascular thrombectomy outcomes

BACKGROUND

The treatment of acute ischemic stroke (AIS) aims to achieve early vascular recanalization and reperfusion of the penumbra. However, the effect of early penumbral imaging within 6 h on clinical outcomes remains unclear. The objective of this study was to determine the effect of magnetic resonance-guided (MR-guided) perfusion imaging within 6 h after symptom onset on endovascular thrombectomy outcomes in AIS patients.

METHODS

We prospectively collected the clinical information of consecutive AIS patients undergoing endovascular thrombectomy based on MR-guided perfusion imaging within 6 h after symptom onset from AISRNA and EVTRNA studies. The primary outcome was defined as the poor outcome (mRS > 2 within 90 days). The perfusion-weighted imaging/diffusion-weighted imaging (PWI/DWI) mismatch was assessed by an automated software.

RESULTS

We enrolled 84 patients (25 in the mismatch ≤ 1.8 group and 59 in the mismatch > 1.8 group). Significant difference was found between the mismatch > 1.8 group and the mismatch ≤ 1.8 group for the incidence of disabling stroke (mRS > 2) within 90 days (40.7% vs. 68.0%, OR: 3.099, 95% CI: 1.154-8.323, P = 0.025). Intracranial hemorrhage occurred in 8 patients (13.6%) in the mismatch > 1.8 group and 10 patients in the mismatch ≤ 1.8 group (40.0%) (P = 0.010). The risk of severe cerebral edema was 2/59 (3.4%) vs. 7/25 (28.0%) (P = 0.004). These findings remained stable after adjustment.

CONCLUSIONS

MR-guided perfusion imaging mismatch profiles within 6 h after symptom onset may be feasible to predictclinical outcomes and reduce clinically ineffective reperfusion after endovascular thrombectomy.

An experimental system for detection and localization of hemorrhage using ultra-wideband microwaves with deep learning

Stroke is a leading cause of mortality and disability. Emergent diagnosis and intervention are critical, and predicated upon initial brain imaging; however, existing clinical imaging modalities are generally costly, immobile, and demand highly specialized operation and interpretation. Low-energy microwaves have been explored as a low-cost, small form factor, fast, and safe probe for tissue dielectric properties measurements, with both imaging and diagnostic potential. Nevertheless, challenges inherent to microwave reconstruction have impeded progress, hence conduction of microwave imaging remains an elusive scientific aim. Herein, we introduce a dedicated experimental framework comprising a robotic navigation system to translate blood-mimicking phantoms within a human head model. An 8-element ultra-wideband array of modified antipodal Vivaldi antennas was developed and driven by a two-port vector network analyzer spanning 0.6-9.0 GHz at an operating power of 1 mW. Complex scattering parameters were measured, and dielectric signatures of hemorrhage were learned using a dedicated deep neural network for prediction of hemorrhage classes and localization. An overall sensitivity and specificity for detection >0.99 was observed, with Rayleigh mean localization error of 1.65 mm. The study establishes the feasibility of a robust experimental model and deep learning solution for ultra-wideband microwave stroke detection.

A low bleeding risk thrombolytic agent: citPA5

AIMS

Alteplase is a cornerstone thrombolytic agent in clinical practice but presents a potential bleeding risk. Stroke patients need pre-screening to exclude haemorrhagic stroke before using alteplase. In this study, we develop a new thrombolytic agent citPA5, characterized by an enhanced safety profile and minimal bleeding tendency.

METHODS AND RESULTS

A clot lysis agent, named citPA5, is developed based on rtPA with point mutations to completely suppress its proteolytic activity in the absence of fibrin. In the presence of fibrin, citPA5 exhibited significantly higher fibrinolytic activity (a 15.8-fold increase of kcat/Km). Furthermore, citPA5 showed resistance to endogenous fibrinolysis inhibitor, PAI-1, resulting in enhanced potency. In a series of safety evaluation experiments, including thrombelastography assay, mice tail bleeding assay, and a murine intracerebral haemorrhage (ICH) model, citPA5 did not cause systemic bleeding or worsen ICH compared with alteplase. This highlights the low risk of bleeding associated with citPA5. Finally, we found that citPA5 effectively improved cerebral blood flow and reduced infarct volume in a carotid embolism-induced stroke model.

CONCLUSION

This clot lysis agent, citPA5, not only exhibits a low risk of bleeding but also demonstrates highly effective thrombolysis capabilities. As a result, citPA5 shows great potential for administration prior to the classification of stroke types, making it possible for use in ambulances at the onset of stroke when symptoms are identified. The findings presented in this study also suggest that this strategy could be applied to develop a new generation of fibrinolytic drugs that offer greater safety and specificity in targeting fibrin.

Benefits of First Pass Recanalization in Basilar Strokes Based on Initial Clinical Severity

PURPOSE

Randomized trials demonstrating the benefits of thrombectomy for basilar artery occlusions have enrolled an insufficient number of patients with a National Institutes for Health Stroke Scale (NIHSS) score < 10 and shown discrepant results for patients with an NIHSS > 20. Achieving a first pass recanalization (FPR) improves clinical outcomes in stroke. We aimed to evaluate the effect of the FPR on outcomes among basilar artery occlusion patients, characterized by prethrombectomy initial NIHSS score.

METHODS

We retrospectively analyzed the Endovascular Treatment in Ischemic Stroke (ETIS) registry of 279 basilar artery occlusion patients treated with thrombectomy from 6 participating centers. We compared the 90-day clinical outcomes of achieving a FPR versus no FPR, categorized by initial clinical severity: mild (NIHSS < 10), moderate (NIHSS 10-20) and severe (NIHSS > 20). We used Poisson regression with robust error variance to determine the effect of the NIHSS score on the association between FPR and outcomes.

RESULTS

The FPR patients with NIHSS < 10 or NIHSS 10-20 were more likely to have a favorable clinical outcome (modified Rankin scale, mRS 0-3) than non-FPR patients (relative risk, RR = 1.32, 95% confidence interval, CI: 1.04, 1.66, p-value = 0.0213, and RR = 1.79, 95% CI: 1.26, 2.53, p-value = 0.0011, respectively). A similar benefit was not found in patients with severe symptoms. We found a significantly lower risk of poor clinical outcome (mRS 4-6) in FPR patients with NIHSS 10-20, but not among patients with an NIHSS > 20.

CONCLUSION

Achieving a FPR in basilar artery occlusion patients with mild (NIHSS < 10) or moderate (NIHSS 10-20) symptoms is associated with better clinical outcomes, but not in patients with severe symptoms. These results support the importance of further clinical trials on the benefits of thrombectomy in severe strokes.

The use of a pre-hospital questionnaire expedited the acute management of patients with ischemic stroke in a comprehensive stroke center

BACKGROUND

Delays in intravenous thrombolysis (IVT) treatment for acute ischemic stroke decrease the benefit of treatment. Difficulties determining a patient's clinical eligibility for IVT is a frequent cause of treatment delays.

OBJECTIVE

We aimed to assess the effectiveness of the "PROVIDENCE" datasheet, a pre- hospital assessment of contraindications for IVT use applied by emergency medical services personnel.

METHODS

We performed a single-center cohort study comparing IVT decision and treatment times between patients with PROVIDENCE datasheets and those without. Patients were eligible if they were over 18 years old and presented to our comprehensive stroke center from the field with stroke-like symptoms with onset within 4.5 hours.

RESULTS

We identified 465 records and included 166 records in our final analysis (54 in the study group and 112 in the control group). A subgroup of 85 patients received IVT (30 in the study group patients and 55 in the control group). The PROVIDENCE datasheet was associated with a faster median time by five minutes from the patient's initial presentation at the emergency department to the final decision regarding IVT eligibility (p = 0.032) and a faster time between the first encounter with a neurology provider and the decision regarding IVT administration by six minutes (p = 0.002) for the entire sample. In the subgroup that received IVT, the PROVIDENCE datasheet decreased the median decision time by seven minutes (p = 0.044) There was no significant difference in door-to-needle times between groups.

CONCLUSION

Using the PROVIDENCE datasheet, first responders can quickly identify potential contraindications for IVT treatment in patients with stroke-like symptoms. This tool expedited decision-making and led to faster IVT administration process at a comprehensive stroke center.

Golden Hour Intravenous Thrombolysis for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

OBJECTIVES

The benefits of intravenous thrombolysis are time-dependent, with maximum efficacy when administered within the first "golden" hour after onset. Nevertheless, the impact of golden hour thrombolysis has not been well quantified.

METHODS

Medline, Embase, and Web of Science databases were systematically searched from inception to August 27, 2023. We included studies that reported safety and efficacy outcomes of ischemic stroke patients treated with intravenous thrombolysis in the golden hour versus later treatment window. The primary outcome was an excellent functional outcome, defined as a modified Rankin Scale score of 0-1 at 90 days. The secondary efficacy outcome was a good functional outcome (defined as modified Rankin Scale score of 0-2). The main safety outcome was symptomatic intracerebral hemorrhage.

RESULTS

Seven studies involving 78,826 patients met the selection criteria. Golden hour thrombolysis was associated with higher odds of 90-day excellent functional outcomes (OR 1.40, 95% CI 1.16-1.67) and 90-day good functional outcomes (OR 1.38, 95% CI 1.13-1.69) compared with thrombolysis outside the golden hour. The number needed to treat to benefit for golden hour thrombolysis to reduce disability by at least 1 level on the modified Rankin Scale per patient was 2.6. Rates of symptomatic intracerebral hemorrhage and mortality were similar between groups.

INTERPRETATION

Golden hour thrombolysis significantly improved acute ischemic stroke outcomes. The findings provide rationale for intensive efforts aimed at expediting thrombolytic therapy within the golden hour window following the onset of acute ischemic stroke. ANN NEUROL 2024;96:582-590.

Large vessel occlusion detection by non-contrast CT using artificial ıntelligence

INTRODUCTION

Computer vision models have been used to diagnose some disorders using computer tomography (CT) and magnetic resonance (MR) images. In this work, our objective is to detect large and small brain vessel occlusion using a deep feature engineering model in acute of ischemic stroke.

METHODS

We use our dataset. which contains 324 patient's CT images with two classes; these classes are large and small brain vessel occlusion. We divided the collected image into horizontal and vertical patches. Then, pretrained AlexNet was utilized to extract deep features. Here, fc6 and fc7 (sixth and seventh fully connected layers) layers have been used to extract deep features from the created patches. The generated features from patches have been concatenated/merged to generate the final feature vector. In order to select the best combination from the generated final feature vector, an iterative selector (iterative neighborhood component analysis-INCA) has been used, and this selector has chosen 43 features. These 43 features have been used for classification. In the last phase, we used a kNN classifier with tenfold cross-validation.

RESULTS

By using 43 features and a kNN classifier, our AlexNet-based deep feature engineering model surprisingly attained 100% classification accuracy.

CONCLUSION

The obtained perfect classification performance clearly demonstrated that our proposal could separate large and small brain vessel occlusion detection in non-contrast CT images. In this aspect, this model can assist neurology experts with the early recanalization chance.

Association of high serum β2-microglobulin levels with poor functional outcomes in patients with acute ischemic stroke: A cohort study

We evaluated the association between serum β2-microglobulin (β2M) levels and prognosis in patients with acute ischemic stroke (AIS) and determined whether the association was affected by any clinical variables. This prospective study included 533 patients with AIS who were admitted to the Hospital of Nanhua Affiliated with the University of South China for treatment from June 1, 2021, to July 31, 2022. Using multiple regression modeling, the association between serum β2M levels and poor functional outcomes-which were classified as being modified Rankin Scale scores of 3 to 6 (composite score of death and major disability), 3 to 5 (major disability), and 6 (death)-were assessed 3 months after stroke onset. At the 3-month follow-up assessment, 209 (47.39%) participants had poor functional outcomes: major disabilities in 150 (34.01%) cases and deaths in 59 (13.38%). After adjusting for important covariates, the group with serum β2M levels in the highest quartile had the highest proportion of individuals with modified Rankin Scale scores of 3 to 6 (odds ratio [OR], 3.54; 95% confidence interval [CI], 1.35-9.33), 3 to 5 (OR, 2.95; 95% CI, 1.21-7.16), or 6 (OR, 1.02; 95% CI, 0.29-3.64) compared with the group having serum β2M levels in the lowest quartiles. The risk prediction for the combined outcome of death and major disability improved after incorporating β2M levels into models that included conventional risk factors. Subgroup analysis revealed a significant impact on the association between serum β2M levels and poor functional outcomes only in patients with AIS whose time from onset to hospitalization was <12 hours (P for interaction < .05). Elevated serum β2M levels were associated with poor functional outcomes in patients with AIS, possibly affected by the time from onset to hospitalization.

Nanocarriers' repartitioning of drugs between blood subcompartments as a mechanism of improving pharmacokinetics, safety, and efficacy

For medical emergencies, such as acute ischemic stroke, rapid drug delivery to the target site is essential. For many small molecule drugs, this goal is unachievable due to poor solubility that prevents intravenous administration, and less obviously, by extensive partitioning to plasma proteins and red blood cells (RBCs), which greatly slows delivery to the target. Here we study these effects and how they can be solved by loading into nanoscale drug carriers. We focus on fingolimod, a small molecule drug that is FDA-approved for treatment of multiple sclerosis, which has also shown promise in the treatment of stroke. Unfortunately, fingolimod has poor solubility and very extensive partitioning to plasma proteins and RBCs (in whole blood, 86% partitions to RBCs, 13.96% to plasma proteins, and 0.04% is free). We develop a liposomal formulation that slows the partitioning of fingolimod to RBCs and plasma proteins, enables intravenous delivery, and additionally prevents fingolimod toxicity to RBCs. The liposomal formulation nearly completely prevented fingolimod adsorption to plasma proteins (association with plasma proteins was 98.4 ± 0.4% for the free drug vs. 5.6 ± 0.4% for liposome-loaded drug). When incubated with whole blood in vitro, the liposomal formulation greatly slowed partitioning of fingolimod to RBCs and also eliminated deleterious effects of fingolimod on RBC rigidity, morphology, and hemolysis. In vivo, the liposomal formulation delayed fingolimod partitioning to RBCs for over 30 min, a critical time window for stroke. Fingolimod-loaded liposomes showed improved efficacy in a mouse model of post-stroke neuroinflammation, completely sealing the leaky blood-brain barrier (114 ± 11.5% reduction in albumin leak into the brain for targeted liposomes vs. 38 ± 16.5% reduction for free drug). This effect was only seen for liposomes modified with antibodies to enable targeted delivery to the site of action, and not in unmodified, long-circulating liposomes. Thus, loading fingolimod into liposomes prevented partitioning to RBCs and associated toxicities and enabled targeted delivery. This paradigm can be used for tuning the blood distribution of small molecule drugs for the treatment of acute illnesses requiring rapid pharmacologic intervention.

Advancing stroke diagnosis and management through nuclear medicine: a systematic review of clinical trials

Introduction

Despite advancements in stroke care, challenges persist in timely triage and treatment initiation to prevent the burden of stroke-related disabilities. Although nuclear medicine has shown promise, no imaging technique has yet provided a sufficiently rapid, precise, and cost-effective approach to routine stroke management. This study aims to review the clinical application of nuclear medicine in stroke diagnosis and treatment.

Methods

A systematic search of the Cochrane, EU Clinical Trials Register, ISRCTN, the International Stroke Trial, and the ClinicalTrials.gov database was conducted to find all registered trials reporting nuclear medicine's clinical applications in stroke up to June 07, 2024.

Results

Among the 220 screened trials, 51 (36 interventional; 15 observational) met the eligibility criteria. Participants were older than 18 years old, with only six studies including pediatric under 17 years old, with a total of 11,262 stroke (9,232 ischemic; 2,030 haemorrhagic) participants. The bias risk varied across trials but remained mostly low to moderate.

Discussion

The review highlighted nuclear medicine's significant contributions to stroke diagnosis and management, notably through mobile stroke units, pre-hospital acute stroke magnetic resonance image (MRI) based biomarkers, and MRI-based stroke mechanisms for 4D flow nuclear imaging. These advancements have generally reduced treatment delays and enhance clinical outcomes post-stroke. Specifically, radiopharmaceutical radiotracers can effectively discriminate between strokes and mimics, particularly in high-risk patients. Integrating novel positron emission tomography (PET) radiotracer 18F glycoprotein 1 and radionuclide angiography may improve sensitivity and specificity in thrombi detection for decisions regarding stenting or carotid endarterectomy, and the single-photon emission computed tomography and PET integration with ferumoxytol radiotracer-enhanced MRI enables functional imaging for evaluating cerebral perfusion, metabolic activity, and neuroinflammatory markers post-stroke. Overall, the integration of nuclear medicine into multimodal imaging equipment like computed-tomography PET and MRI-PET offers a more comprehensive picture of the brain. Nevertheless, further research is needed on novel stroke imaging techniques and standardization across stroke centers for optimal performance.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024541680, identifier PROSPERO CRD(42024541680).

Temporal structures that determine consistency and quality of care: a case study in hyperacute stroke services

BACKGROUND

Temporal structuring is determined by practices and social norms and affects the quality and timing of care. In this case study of hyperacute stroke wards which provide initial stroke investigation, treatment and care, we explored temporal structuring patterns to explain how these may affect quality of care.

METHODS

This paper presents a thematic analysis of qualitative interviews with hyperacute stroke staff (n=76), non-participant observations (n=41, ~102 hours) and documentary analysis of the relevant service standards guidance. We used an inductive coding process to generate thematic findings around the concept of temporal structuring, with graphically illustrated examples.

RESULTS

Five temporal structures influence what-happens-when: (1) clinical priorities and quality assurance metrics motivate rapid activity for the initial life-prolonging assessments and interventions; (2) static features of ward organisation such as rotas and ward rounds impact consistency of care, determining timing and quality of care for patients; (3) some services experimented with staff rotas to try to meet peaks in demand, sometimes unsuccessfully; (4) implicit social norms or heuristics about perceived necessity affected staff motivation to make changes or improvements to consistency of care, particularly around weekend work; and (5) after-effects such as bottlenecks or backlogs affect quality of care, which are hard to measure effectively to drive service improvement.

CONCLUSIONS

Patients need temporally consistent high quality of care. Temporal consistency stems from the design of services, including staffing, targets and patient pathway design as well as cultural attitudes to working patterns. Improvements to consistency of care will be limited without changes to structures such as rotas and ward rounds, but also social norms around weekend work for certain professional groups.

YouTube as a source of recognizing acute stroke; progress in 2 years

BACKGROUND

YouTube™ has a great role in providing information, which includes educational videos, to more than 2 billion users, making it the second most popular application in the world. BE-FAST is a modified version of the FAST mnemonic and is used to detect acute ischemic stroke by the patients or their relatives. The purpose of this study is to assess the overall usefulness of the information of YouTube in patients to realize an acute stroke attack.

METHODS

YouTube was searched for the following five terms: "stroke", ''stroke diagnosis", "stroke signs", "brain attack" and "what is stroke" in November 2021 and May 2023, separately. Two independent neurology specialists scored each video by using Global Quality Scale (GQS).

RESULTS

Among the total of 150 videos, the number that met inclusion criteria was 91 for the November 2021 search and 104 for the May 2023 search. For the 2021 search, in 30 videos (33%), the FAST mnemonic or its contents were noticed, whereas BE-FAST was mentioned in only four videos (4.4%). For the 2023 search, the FAST mnemonic or its contents were noticed in 36 videos (34.6%) and BE-FAST was mentioned in 11 videos (10.6%). Among the 2021 and 2023 searches, the mean GQS values were 3.09 and 2.96 points, 50 (54.8%) vs. 56 (53.8%) videos rated 3.5 points or higher (high quality), respectively. GQS scores of the videos mentioning balance, eyes, face, arms, speech, and time, the basic and advanced information about radiology and treatment, and mentioning FAST, BE-FAST, and TPA were significantly higher.

CONCLUSION

We conclude that YouTube is not yet a very useful tool for patients to realize that they may have acute ischemic stroke, though over the years; information available on social media for healthcare information and education has improved.

Endovascular Stroke Thrombectomy for Patients With Large Ischemic Core: A Review

Importance

Recently, 6 randomized clinical trials-RESCUE-Japan-LIMIT (Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism-Japan Large Ischemic Core Trial), ANGEL-ASPECT (Trial of Endovascular Therapy for Acute Ischemic Stroke With Large Infarct), SELECT2 (Trial of Endovascular Thrombectomy for Large Ischemic Strokes), TESLA (Thrombectomy for Emergent Salvage of Large Anterior Circulation Ischemic Stroke), TENSION (Endovascular Thrombectomy for Acute Ischemic Stroke With Established Large Infarct), and LASTE (Large Stroke Therapy Evaluation)-have concluded their investigations on the efficacy and safety of endovascular thrombectomy (EVT) for the treatment of patients with ischemic stroke, anterior-circulation large vessel occlusions, and large areas of ischemic changes defined as an Alberta Stroke Program Early Computed Tomography Score (ASPECTS) of 5 or less. Overall, the results appeared to be positive, with 5 of the 6 trials meeting their primary efficacy end point, and 1 trial that was a near miss. However, questions remain regarding how these trial results should be interpreted and incorporated into routine clinical practice.

Observations

In this narrative review and analysis of published trials, important nuances of the available clinical data were identified, and important areas of lingering uncertainty were highlighted, including the efficacy and safety of EVT for patients with a low ASPECTS score in late treatment windows and those with large core volumes. Also emphasized was the possibly important role of advanced neuroimaging modalities such as perfusion and magnetic resonance imaging when making EVT treatment decisions for select patients with low ASPECTS scores.

Conclusions and Relevance

Recent trial data provide strong evidence that EVT is safe and effective for patients with anterior, large vessel-occlusion stroke and low ASPECTS scores who present within 6 hours from stroke onset. However, patient outcomes often remain poor despite EVT treatment. The efficacy and safety of EVT for patients with low ASPECTS scores who present beyond 6 hours of stroke onset remain uncertain, and the current trial data seem too scarce to justify forgoing advanced stroke imaging during this extended time window. Furthermore, the efficacy and safety of EVT for patients with large core volumes (100 mL or greater) or M2 occlusions (ie, occlusions of the second segment of the middle cerebral artery) remain uncertain. Future research to better identify patients likely to meaningfully respond to EVT is needed to further optimize the stroke triage process and health care resource utilization.

Acute myocardial infarction and ischaemic stroke: differences and similarities in reperfusion therapies-a review

Acute ST-elevation myocardial infarction (STEMI) and acute ischaemic stroke (AIS) share a number of similarities. However, important differences in pathophysiology demand a disease-tailored approach. In both conditions, fast treatment plays a crucial role as ischaemia and eventually infarction develop rapidly. Furthermore, in both fields, the introduction of fibrinolytic treatments historically preceded the implementation of endovascular techniques. However, in contrast to STEMI, only a minority of AIS patients will eventually be considered eligible for reperfusion treatment. Non-invasive cerebral imaging always precedes cerebral angiography and thrombectomy, whereas coronary angiography is not routinely preceded by non-invasive cardiac imaging in patients with STEMI. In the late or unknown time window, the presence of specific patterns on brain imaging may help identify AIS patients who benefit most from reperfusion treatment. For STEMI, a uniform time window for reperfusion up to 12 h after symptom onset, based on old placebo-controlled trials, is still recommended in guidelines and generally applied. Bridging fibrinolysis preceding endovascular treatment still remains the mainstay of reperfusion treatment in AIS, while primary percutaneous coronary intervention is the strategy of choice in STEMI. Shortening ischaemic times by fine-tuning collaboration networks between ambulances, community hospitals, and tertiary care hospitals, optimizing bridging fibrinolysis, and reducing ischaemia-reperfusion injury are important topics for further research. The aim of this review is to provide insights into the common as well as diverging pathophysiology behind current reperfusion strategies and to explore new ways to enhance their clinical benefit.

Development of an Acute Stroke Care Seeking Framework

ABSTRACT

BACKGROUND: A multitude of variables influence an individual's decision to seek care in emergency situations. By recognizing these variables and their impact on the timeline of an individual seeking care for a stroke, nurses have an opportunity to positively affect the outcomes of stroke within the community. The purpose of this narrative review was to develop a research framework describing the variables involved in care seeking during an acute stroke. METHODS: Using a theory synthesis methodology that included variable identification and the establishment of relationships between variables based on existing literature, a framework describing variables relevant to acute stroke care seeking behavior was developed. RESULTS: Fourteen recently published studies reported significant variables related to seeking emergency medical care during the hyperacute phase of a stroke. Eight variables were identified and characterized as either promoters or distractors. Promoters led an individual to seek acute stroke care earlier, such as perceived symptom severity, stroke knowledge, and the presence of others. Distractors led an individual to delay seeking acute stroke care and resulted in later hospital arrival times, such as a lack of social network or resources, comorbid conditions, and incongruity with the local health system. CONCLUSION: Although individual decision making is exceedingly complex and varies by individual and situation, the developed acute stroke care seeking framework may provide a basis on which to develop stroke awareness programs and interventions targeted at individuals at risk for delayed acute stroke care.

Region-specific protective effects of monomethyl fumarate in cerebellar and hippocampal organotypic slice cultures following oxygen-glucose deprivation

To date, apart from moderate hypothermia, there are almost no adequate interventions available for neuroprotection in cases of brain damage due to cardiac arrest. Affected persons often have severe limitations in their quality of life. The aim of this study was to investigate protective properties of the active compound of dimethyl fumarate, monomethyl fumarate (MMF), on distinct regions of the central nervous system after ischemic events. Dimethyl fumarate is an already established drug in neurology with known anti-inflammatory and antioxidant properties. In this study, we chose organotypic slice cultures of rat cerebellum and hippocampus as an ex vivo model. To simulate cardiac arrest and return of spontaneous circulation we performed oxygen-glucose-deprivation (OGD) followed by treatments with different concentrations of MMF (1-30 μM in cerebellum and 5-30 μM in hippocampus). Immunofluorescence staining with propidium iodide (PI) and 4',6-diamidine-2-phenylindole (DAPI) was performed to analyze PI/DAPI ratio after imaging with a spinning disc confocal microscope. In the statistical analysis, the relative cell death of the different groups was compared. In both, the cerebellum and hippocampus, the MMF-treated group showed a significantly lower PI/DAPI ratio compared to the non-treated group after OGD. Thus, we showed for the first time that both cerebellar and hippocampal slice cultures treated with MMF after OGD are significantly less affected by cell death.

Multicenter validation of synthetic FLAIR as a substitute for FLAIR sequence in acute ischemic stroke

PURPOSE

To evaluate performance of synthetic and real FLAIR for identifying early stroke in a multicenter cohort.

METHODS

This retrospective study was conducted using DWI and FLAIR extracted from the Endovascular Treatment in Ischemic Stroke image registry (2017-2021). The database was partitioned into subsets according to MRI field strength and manufacturer, and randomly divided into training set (70%) used for model fine-tuning, validation set (15%), and test set (15%). In test set, five readers, blinded to FLAIR sequence type, assessed DWI-FLAIR mismatch using real and synthetic FLAIR. Interobserver agreement for DWI-FLAIR rating and concordance between synthetic and real FLAIR were evaluated with kappa statistics. Sensitivity and specificity for identification of ⩽4.5 h AIS were compared in patients with known onset-to-MRI delay using McNemar's test.

RESULTS

1454 complete MRI sets (1172 patients, median (IQR) age: 73 years (62-82); 762 women) acquired on 125 MRI units were analyzed. In test set (207 MRI), interobserver reproducibility for DWI-FLAIR mismatch labeling was substantial for real and synthetic FLAIR (Fleiss κ = 0.79 (95%CI: 0.73-0.84) and 0.77 (95%CI: 0.71-0.82), respectively). After consensus, concordance between real and synthetic FLAIR was excellent (κ = 0.85 (95%CI: 0.78-0.92)). In 141 MRI sets with known onset-to-MRI delay, diagnostic performances for ⩽4.5 h AIS identification did not differ between real and synthetic FLAIR (sensitivity: 60/71 (85%) vs 59/71 (83%), p = .56; specificity: 65/70 (93%) vs 65/70 (93%), p > 0.99).

CONCLUSION

A deep-learning-based FLAIR fine-tuned on multicenter data can provide comparable performances to real FLAIR for early AIS identification. This approach may help reducing MR protocol duration and motion artifacts.

Does on-site computed tomography matter? A cross-sectional study of stroke patients' door-to-scan-time in rural hospitals

PURPOSE

Many rural Australian hospitals lack on-site computed tomography (CT). These hospitals often refer patients to local off-site private radiology clinics or to central hospitals, challenging the achievement of time-sensitive scans. For stroke patients, timely access to CT affects treatment options. This study questions whether on-site CT matters in rural hospitals by investigating stroke patients' door-to-scan-time (DTST) and CT scan sequence referrals.

METHOD

A retrospective chart audit was completed across four rural hospitals; two with on-site CT and two without. Adult emergency stroke presentations were randomly sampled. Comparisons between on-site and off-site CT hospitals were made for DTST and CT sequence referrals using Mann-Whitney U-tests and Fisher's exact tests.

RESULTS

A total of 120 charts were audited (on-site CT, n = 60; off-site CT, n = 60). DTST was longer for off-site vs. on-site CT hospitals (median = 4.30 h vs. median = 0.70 h; U = 338, p < 0.001) regardless of whether presentations occurred in business hours or out of hours (p < 0.001). Off-site CT hospitals ordered less CT angiography or perfusion scanning (32% vs. 85%, p < 0.001).

CONCLUSIONS

Off-site CT hospital patients had longer DTST and received less angiography or perfusion scanning. These findings suggest that on-site CT matters to rural stroke patients by improving equitable access to CT and appropriate scan referrals.

Artificial Intelligence-based automated CT brain interpretation to accelerate treatment for acute stroke in rural India: An interrupted time series study

In resource-limited settings, timely treatment of acute stroke is dependent upon accurate diagnosis that draws on non-contrast computed tomography (NCCT) scans of the head. Artificial Intelligence (AI) based devices may be able to assist non-specialist physicians in NCCT interpretation, thereby enabling faster interventions for acute stroke patients in these settings. We evaluated the impact of an AI device by comparing the time to intervention (TTI) from NCCT imaging to significant intervention before (baseline) and after the deployment of AI, in patients diagnosed with stroke (ischemic or hemorrhagic) through a retrospective interrupted time series analysis at a rural hospital managed by non-specialists in India. Significant intervention was defined as thrombolysis or antiplatelet therapy in ischemic strokes, and mannitol for hemorrhagic strokes or mass effect. We also evaluated the diagnostic accuracy of the software using the teleradiologists' reports as ground truth. Impact analysis in a total of 174 stroke patients (72 in baseline and 102 after deployment) demonstrated a significant reduction of median TTI from 80 minutes (IQR: 56·8-139·5) during baseline to 58·50 (IQR: 30·3-118.2) minutes after AI deployment (Wilcoxon rank sum test-location shift: -21·0, 95% CI: -38·0, -7·0). Diagnostic accuracy evaluation in a total of 864 NCCT scans demonstrated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) in detecting intracranial hemorrhage to be 0·89 (95% CI: 0·83-0·93), 0·99 (0·98-1·00), 0·96 (0·91-0·98) and 0·97 (0·96-0·98) respectively, and for infarct these were 0·84 (0·79-0·89), 0·81 (0·77-0·84), 0·58 (0·52-0·63), and 0·94 (0·92-0·96), respectively. AI-based NCCT interpretation supported faster abnormality detection with high accuracy, resulting in persons with acute stroke receiving significantly earlier treatment. Our results suggest that AI-based NCCT interpretation can potentially improve uptake of lifesaving interventions for acute stroke in resource-limited settings.

Continuous non-invasive vs. invasive arterial blood pressure monitoring during neuroradiological procedure: a comparative, prospective, monocentric, observational study

BACKGROUND

In the perioperative setting, the most accurate way to continuously measure arterial blood pressure (ABP) is using an arterial catheter. Surrogate methods such as finger cuff have been developed to allow non-invasive measurements and are increasingly used, but need further evaluation. The aim of this study is to evaluate the accuracy and clinical concordance between two devices for the measurement of ABP during neuroradiological procedure.

METHODS

This is a prospective, monocentric, observational study. All consecutive patients undergoing a neuroradiological procedure were eligible. Patients who needed arterial catheter for blood pressure measurement were included. During neuroradiological procedure, ABP (systolic, mean and diatolic blood pressure) was measured with two different technologies: radial artery catheter and Nexfin. Bland-Altman and error grid analyses were performed to evaluate the accuracy and clinical concordance between devices.

RESULTS

From March 2022 to November 2022, we included 50 patients, mostly ASA 3 (60%) and required a cerebral embolization (94%) under general anaesthesia (96%). Error grid analysis showed that 99% of non-invasive ABP measures obtained with the Nexfin were located in the risk zone A or B. However, 65.7% of hypertension events and 41% of hypotensive events were respectively not detected by Nexfin. Compared to the artery catheter, a significant relationship was found for SAP (r2 = 0.78) and MAP (r2 = 0.80) with the Nexfin (p < 0.001). Bias and limits of agreement (LOA) were respectively 9.6 mmHg (- 15.6 to 34.8 mmHg) and - 0.8 mmHg (- 17.2 to 15.6 mmHg), for SAP and MAP.

CONCLUSIONS

Nexfin is not strictly interchangeable with artery catheter for ABP measuring. Further studies are needed to define its clinical use during neuroradiological procedure.

TRIAL REGISTRATION

Clinicaltrials.gov, registration number: NCT05283824.

The Contribution of the Triage Nurse in the Optimisation of Door-to-Computed-Tomography Time in Stroke

A stroke is a time-sensitive emergency, so diagnosing and treating the victim promptly is extremely important. Therefore, the purpose of this study was to identify the influence of the Stroke Code Protocol's activation on the door-to-computed-tomography (door-to-CT) time and determine whether factors such as previous Modified Rankin Scale (mRS), age, and gender influence its activation. A retrospective study was conducted in a Medical-Surgical Emergency Department in the centre of Portugal from 1 January 2021 to 31 December 2022. The sample was selected according to the diagnosis assigned at the time of clinical discharge from the Emergency Department and the Stroke Code Protocol activation criteria. It was observed that 113 (50%) suspected stroke victims who met the activation criteria for the Stroke Code Protocol did not have the protocol activated, which had a highly significant influence (p < 0.001) on door-to-CT time. It was determined that activation at triage has an average door-to-CT time of 35 ± 18 min, post-triage activation has an average door-to-CT time of 38 ± 26 min, and non-activation has an average door-to-CT time of 1 h 04 ± 45 min. The need to implement an institutional protocol for activating the Stroke Code Protocol and provide specialised training for the multidisciplinary team is reiterated.

The Role of the Complement System in Synaptic Pruning after Stroke

Stroke is a serious disease that can lead to local neurological dysfunction and cause great harm to the patient's health due to blood cerebral circulation disorder. Synaptic pruning is critical for the normal development of the human brain, which makes the synaptic circuit completer and more efficient by removing redundant synapses. The complement system is considered a key player in synaptic loss and cognitive impairment in neurodegenerative disease. After stroke, the complement system is over-activated, and complement proteins can be labeled on synapses. Microglia and astrocytes can recognize and engulf synapses through corresponding complement receptors. Complement-mediated excessive synaptic pruning can cause post-stroke cognitive impairment (PSCI) and secondary brain damage. This review summarizes the latest progress of complement-mediated synaptic pruning after stroke and the potential mechanisms. Targeting complement-mediated synaptic pruning may be essential for exploring therapeutic strategies for secondary brain injury (SBI) and neurological dysfunction after stroke.

A Comparison of CT Perfusion Output of RapidAI and Viz.ai Software in the Evaluation of Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Automated CTP postprocessing packages have been developed for managing acute ischemic stroke. These packages use image processing techniques to identify the ischemic core and penumbra. This study aimed to investigate the agreement of decision-making rules and output derived from RapidAI and Viz.ai software packages in early and late time windows and to identify predictors of inadequate quality CTP studies.

MATERIALS AND METHODS

One hundred twenty-nine patients with acute ischemic stroke who had CTP performed on presentation were analyzed by RapidAI and Viz.ai. Volumetric outputs were compared between packages by performing Spearman rank-order correlation and Wilcoxon signed-rank tests with subanalysis performed at early (<6 hours) and extended (>6 hours) time windows. The concordance of selecting patients on the basis of DAWN and DEFUSE 3 eligibility criteria was assessed using the McNemar test.

RESULTS

One hundred eight of 129 patients were found to have adequate-quality studies. Spearman rank-order correlation coefficients were calculated on time-to-maximum >6-second volume, time-to-maximum >10-second volume, CBF <30% volume, mismatch volume, and mismatch ratio between both software packages with correlation coefficients of 0.82, 0.65, 0.77, 0.78, 0.59, respectively. The Wilcoxon signed-rank test was also performed on time-to-maximum >6-second volume, time-to-maximum >10-second volume, CBF <30% volume, mismatch volume, and mismatch ratio with P values of .30, .016, <.001, .03, <.001, respectively. In a 1-sided test, CBF <30% was greater in Viz.ai (P < .001). Although this finding resulted in statistically significant differences, it did not cause clinically significant differences when applied to the DAWN and DEFUSE 3 criteria. A lower ejection fraction predicted an inadequate study in both software packages (P = .018; 95% CI, 0.01-0.113) and (P = .024; 95% CI, 0.008-0.109) for RapidAI and Viz.ai, respectively.

CONCLUSIONS

Penumbra and infarct core predictions between Rapid and Viz.ai correlated but were statistically different and resulted in equivalent triage using DAWN and DEFUSE3 criteria. Viz.ai predicted higher ischemic core volumes than RapidAI. Viz.ai predicted lower combined core and penumbra values than RapidAI at lower volumes and higher estimates than RapidAI at higher volumes. Clinicians should be cautious when using different software packages for clinical decision-making.

Parallel activation of helicopter and ground transportation after dispatcher identification of suspected anterior large vessel occlusion stroke in rural areas: a proof-of-concept case with modeling from the LESTOR trial

BACKGROUND

When stroke patients with suspected anterior large vessel occlusion (aLVO) happen to live in rural areas, two main options exist for prehospital transport: (i) the drip-and-ship (DnS) strategy, which ensures rapid access to intravenous thrombolysis (IVT) at the nearest primary stroke center but requires time-consuming interhospital transfer for endovascular thrombectomy (EVT) because the latter is only available at comprehensive stroke centers (CSC); and (ii) the mothership (MS) strategy, which entails direct transport to a CSC and allows for faster access to EVT but carries the risk of IVT being delayed or even the time window being missed completely. The use of a helicopter might shorten the transport time to the CSC in rural areas. However, if the aLVO stroke is only recognized by the emergency service on site, the helicopter must be requested in addition, which extends the prehospital time and partially negates the time advantage. We hypothesized that parallel activation of ground and helicopter transportation in case of aLVO suspicion by the dispatcher (aLVO-guided dispatch strategy) could shorten the prehospital time in rural areas and enable faster treatment with IVT and EVT.

METHODS

As a proof-of-concept, we report a case from the LESTOR trial where the dispatcher suspected an aLVO stroke during the emergency call and dispatched EMS and HEMS in parallel. Based on this case, we compare the provided aLVO-guided dispatch strategy to the DnS and MS strategies regarding the times to IVT and EVT using a highly realistic modeling approach.

RESULTS

With the aLVO-guided dispatch strategy, the patient received IVT and EVT faster than with the DnS or MS strategies. IVT was administered 6 min faster than in the DnS strategy and 22 min faster than in the MS strategy, and EVT was started 47 min earlier than in the DnS strategy and 22 min earlier than in the MS strategy.

CONCLUSION

In rural areas, parallel activation of ground and helicopter emergency services following dispatcher identification of stroke patients with suspected aLVO could provide rapid access to both IVT and EVT, thereby overcoming the limitations of the DnS and MS strategies.

The Urban-Rural Divide in Neurocritical Care in Low-Income and Middle-Income Countries

The term "urban-rural divide" encompasses several dimensions and has remained an important concern for any country. The economic disparity; lack of infrastructure; dearth of medical specialists; limited opportunities to education, training, and health care; lower level of sanitation; and isolating effect of geographical location deepens this gap, especially in low-income and middle-income countries (LMICs). This article gives an overview of the rural-urban differences in terms of facilities related to neurocritical care (NCC) in LMICs. Issues related to common clinical conditions such as stroke, traumatic brain injury, myasthenia gravis, epilepsy, tubercular meningitis, and tracheostomy are also discussed. To facilitate delivery of NCC in resource-limited settings, proposed strategies include strengthening preventive measures, focusing on basics, having a multidisciplinary approach, promoting training and education, and conducting cost-effective research and collaborative efforts. The rural areas of LMICs bear the maximum impact because of their limited access to preventive health services, high incidence of acquired brain injury, inability to have timely management of neurological emergencies, and scarcity of specialist services in a resource-deprived health center. An increase in the health budget allocation for rural areas, NCC education and training of the workforce, and provision of telemedicine services for rapid diagnosis, management, and neurorehabilitation are some of the steps that can be quite helpful.

Air or Ground Transport to the Critical Care Resuscitation Unit: Does It Really Matter?

OBJECTIVE

Critically ill patients requiring urgent interventions or subspecialty care often require transport over significant distances to tertiary care centers. The optimal method of transportation (air vs. ground) is unknown. We investigated whether air transport was associated with lower mortality for patients being transferred to a specialized critical care resuscitation unit (CCRU).

METHODS

This was a retrospective study of all adult patients transferred to the CCRU at the University of Maryland Medical Center in 2018. Our primary outcome was hospital mortality. The secondary outcomes included the length of stay and the time to the operating room (OR) for patients undergoing urgent procedures. We performed optimal 1:2 propensity score matching for each patient's need for air transport.

RESULTS

We matched 198 patients transported by air to 382 patients transported by ground. There was no significant difference between demographics, the initial Sequential Organ Failure Assessment score, or hospital outcomes between groups. One hundred sixty-four (83%) of the patients transported via air survived to hospital discharge compared with 307 (80%) of those transported by ground (P = .46). Patients transported via air arrived at the CCRU more quickly (127 [100-178] vs. 223 [144-332] minutes, P < .001) and were more likely (60 patients, 30%) to undergo urgent surgical operation within 12 hours of CCRU arrival (30% vs. 17%, P < .001). For patients taken to the OR within 12 hours of arriving at the CCRU, patients transported by air were more likely to go to the OR after 200 minutes since the transfer request (P = .001).

CONCLUSION

The transportation mode used to facilitate interfacility transfer was not significantly associated with hospital mortality or the length of stay for critically ill patients.

Hypotension During Vasopressor Infusion Occurs in Predictable Clusters: A Multicenter Analysis

Background: Published evidence indicates that mean arterial pressure (MAP) below a goal range (hypotension) is associated with worse outcomes, though MAP management failures are common. We sought to characterize hypotension occurrences in ICUs and consider the implications for MAP management. Methods: Retrospective analysis of 3 hospitals' cohorts of adult ICU patients during continuous vasopressor infusion. Two cohorts were general, mixed ICU patients and one was exclusively acute spinal cord injury patients. "Hypotension-clusters" were defined where there were ≥10 min of cumulative hypotension over a 60-min period and "constant hypotension" was ≥10 continuous minutes. Trend analysis was performed (predicting future MAP using 14 min of preceding MAP data) to understand which hypotension-clusters could likely have been predicted by clinician awareness of MAP trends. Results: In cohorts of 155, 66, and 16 ICU stays, respectively, the majority of hypotension occurred within the hypotension-clusters. Failures to keep MAP above the hypotension threshold were notable in the bottom quartiles of each cohort, with hypotension durations of 436, 167, and 468 min, respectively, occurring within hypotension-clusters per day. Mean arterial pressure trend analysis identified most hypotension-clusters before any constant hypotension occurred (81.2%-93.6% sensitivity, range). The positive predictive value of hypotension predictions ranged from 51.4% to 72.9%. Conclusions: Across 3 cohorts, most hypotension occurred in temporal clusters of hypotension that were usually predictable from extrapolation of MAP trends.

Predictions for functional outcome and mortality in acute ischaemic stroke following successful endovascular thrombectomy

Background

Accurate outcome predictions for patients who had ischaemic stroke with successful reperfusion after endovascular thrombectomy (EVT) may improve patient treatment and care. Our study developed prediction models for key clinical outcomes in patients with successful reperfusion following EVT in an Australian population.

Methods

The study included all patients who had ischaemic stroke with occlusion in the proximal anterior cerebral circulation and successful reperfusion post-EVT over a 7-year period. Multivariable logistic regression and Cox regression models, incorporating bootstrap and multiple imputation techniques, were used to identify predictors and develop models for key clinical outcomes: 3-month poor functional status; 30-day, 1-year and 3-year mortality; survival time.

Results

A total of 978 patients were included in the analyses. Predictors associated with one or more poor outcomes include: older age (ORs for every 5-year increase: 1.22-1.40), higher premorbid functional modified Rankin Scale (ORs: 1.31-1.75), higher baseline National Institutes of Health Stroke Scale (ORs: 1.05-1.07) score, higher blood glucose (ORs: 1.08-1.19), larger core volume (ORs for every 10 mL increase: 1.10-1.22), pre-EVT thrombolytic therapy (ORs: 0.44-0.56), history of heart failure (outcome: 30-day mortality, OR=1.87), interhospital transfer (ORs: 1.42 to 1.53), non-rural/regional stroke onset (outcome: functional dependency, OR=0.64), longer onset-to-groin puncture time (outcome: 3-year mortality, OR=1.08) and atherosclerosis-caused stroke (outcome: functional dependency, OR=1.68). The models using these predictors demonstrated moderate predictive abilities (area under the receiver operating characteristic curve range: 0.752-0.796).

Conclusion

Our models using real-world predictors assessed at hospital admission showed satisfactory performance in predicting poor functional outcomes and short-term and long-term mortality for patients with successful reperfusion following EVT. These can be used to inform EVT treatment provision and consent.

Assessing the effectiveness of artificial intelligence (AI) in prioritising CT head interpretation: study protocol for a stepped-wedge cluster randomised trial (ACCEPT-AI)

INTRODUCTION

Diagnostic imaging is vital in emergency departments (EDs). Accessibility and reporting impacts ED workflow and patient care. With radiology workforce shortages, reporting capacity is limited, leading to image interpretation delays. Turnaround times for image reporting are an ED bottleneck. Artificial intelligence (AI) algorithms can improve productivity, efficiency and accuracy in diagnostic radiology, contingent on their clinical efficacy. This includes positively impacting patient care and improving clinical workflow. The ACCEPT-AI study will evaluate Qure.ai's qER software in identifying and prioritising patients with critical findings from AI analysis of non-contrast head CT (NCCT) scans.

METHODS AND ANALYSIS

This is a multicentre trial, spanning four diverse sites, over 13 months. It will include all individuals above the age of 18 years who present to the ED, referred for an NCCT. The project will be divided into three consecutive phases (pre-implementation, implementation and post-implementation of the qER solution) in a stepped-wedge design to control for adoption bias and adjust for time-based changes in the background patient characteristics. Pre-implementation involves baseline data for standard care to support the primary and secondary outcomes. The implementation phase includes staff training and qER solution threshold adjustments in detecting target abnormalities adjusted, if necessary. The post-implementation phase will introduce a notification (prioritised flag) in the radiology information system. The radiologist can choose to agree with the qER findings or ignore it according to their clinical judgement before writing and signing off the report. Non-qER processed scans will be handled as per standard care.

ETHICS AND DISSEMINATION

The study will be conducted in accordance with the principles of Good Clinical Practice. The protocol was approved by the Research Ethics Committee of East Midlands (Leicester Central), in May 2023 (REC (Research Ethics Committee) 23/EM/0108). Results will be published in peer-reviewed journals and disseminated in scientific findings (ClinicalTrials.gov: NCT06027411) TRIAL REGISTRATION NUMBER: NCT06027411.

Palliative Care of Stroke Patients

Critical care clinicians frequently care for patients with acute brain injury, such as stroke. Regardless of the severity of the neurologic insult, these patients have life-altering deficits that threaten their personal identity and quality of life. The sudden nature of the injury often means that there has been little discussion between patients and their families about life-sustaining treatments, and most patients are unable to speak for themselves because of impaired cognition and communication. Thus, individuals experiencing stroke and their families present clinicians with unique and complex care needs in the acute care setting. Key professional organizations have endorsed the early integration of palliative care into the treatment of patients with stroke and devastating neurologic injury. Implementing interdisciplinary primary or specialty palliative care helps clinicians adopt a patient-centered approach to care and aids in decision-making.

Knowledge of cardiovascular diseases and associated risk factors in the general adult population of Jeddah, Saudi Arabia: A cross-sectional study examining gender disparities

To assess knowledge about cardiovascular diseases (CVD) among the general population, we emphasized gender-related disparities and other lifestyle and health-related factors. This cross-sectional study was conducted among 395 individuals from the general population of Jeddah, Saudi Arabia. An online questionnaire was administered to assess knowledge of CVD types, symptoms, and risk factors. The majority of participants identified coronary heart disease (73.7%) as having CVD, with no sex effect. Males had higher knowledge regarding cerebrovascular disease (44% vs 31.5%) and congenital heart diseases (60% vs 51.9%) as being part of CVD, while they had lower knowledge of peripheral arterial disease (44% vs 50.7%) than females, respectively (P < .05). Males exhibited better knowledge of heart attack and stroke symptoms than females. Knowledge was optimal for major CVD risk factors, such as smoking (90.6%) and high low-density lipoprotein cholesterol levels (85.1%); however, gaps were observed in recognizing diabetes (56.2%) and stress (69.4%) as factors for CVD. The mean overall knowledge score was 16.33 ± 5.72 25, with no difference between sexes (P = .239). Predictors of good CVD knowledge included university-level education, daily healthy food consumption, and perceived life as highly stressful; nonetheless, sex showed no significant effect. While the general population displayed a suboptimal understanding of CVD, notable sex disparities were observed, highlighting the need for tailored public health interventions. Emphasizing cognitive and behavioral aspects can foster better prevention and management strategies, given the evident gender disparities.

Stroke and Transient Ischemic Attack

Cerebrovascular disease is a common and potentially life-threatening illness if not triaged and/or treated appropriately. The diagnosis is made based on a combination of clinical history and neuroimaging studies. The majority of strokes can be prevented, and this process often begins in the primary care office through the careful assessment of vascular risk factors. Appropriate workup aims to pinpoint a pathogenic mechanism and guide therapy. Stroke treatment has rapidly advanced over the past several years, resulting in improved outcomes.

Time is brain, so we must BEFAST: Improving stroke identification and triage in a rural emergency department

OBJECTIVE

Shoalhaven District Memorial Hospital is a rural (MM3) secondary hospital which is over an hour travel time from the nearest tertiary centre. The objective of the present study was to pilot the implementation of the BEFAST (Balance, Eyes, Face, Arms, Speech and Time) stroke screening tool at the ED, and determine whether its usage improved timely stroke detection.

METHODS

During initial implementation and training (October-December 2019), triage nurses consulted with senior medical officers before activating stroke calls. Data were collected for the subsequent 24 months (January 2020-2022), and retrospective records for confirmed strokes during a 24-month period prior to BEFAST implementation (October 2017-2019) were also collected. The main outcome measures were triage category, CT scan result time, discharge destination, length of stay (LOS) and Modified Rankin Score (MRS).

RESULTS

After BEFAST implementation, patients (n = 268) were three times more likely to be triaged at category 1 or 2, and door-to-CT scan time was reduced by 20.7 min on average. More patients were discharged to their usual residence and more quickly (LOS 7.9 vs 11.1 days). MRS 90 days after stroke was less, and patients were nearly twice as likely to experience an improvement in neurological symptoms.

CONCLUSIONS

Patient outcomes were improved after implementation of the BEFAST stroke triage tool. More stroke patients were identified upon presentation to the ED, and in a timely fashion. For those with a stroke diagnosis, time-critical interventions can take place earlier, allowing patients to return home sooner, and with less disability.

Diagnostic accuracy of large and medium vessel occlusions in acute stroke imaging by neurology residents and stroke fellows: A comparison of CT angiography alone and CT angiography with CT perfusion

INTRODUCTION

Neurology senior residents and stroke fellows are first to clinically assess and interpret imaging studies of patients presenting to the emergency department with acute stroke. The aim of this study was to compare the diagnostic accuracy of brain CT angiography (CTA) with and without CT perfusion (CTP) between neurology senior residents and stroke fellows.

METHODS

In this neuroimaging study, nine practitioners (four senior neurology residents (SNRs) and five stroke fellows (SFs)) clinically assessed and interpreted the imaging data of 50 cases (15 normal images, 21 large vessel occlusions (LVOs) and 14 medium vessel occlusions (MeVOs) in two sessions, 1 week apart in comparison to final diagnosis of experienced neuroradiologist and experienced stroke neurologist consensus. Interrater agreement of CTA alone and CTA with CTP was quantified using kappa statistics, sensitivity, specificity and overall accuracy.

RESULTS

Overall, arterial occlusions were correctly identified in 221/315 (70.1%) with CTA alone and in 266/315 (84.4%) with CTA and CTP (p < 0.001). The sensitivity of overall arterial occlusions detection with CTA alone was 94.2% (95% CI: 90.8%-96.6%) while with addition of CTP was 98% (95% CI: 95.6%-99.3%), The specificity of CTA alone was 74.7% (95% CI: 67.2%-81.3%) which increased with CTP to 84.4% (95% CI: 77.7%-89.8%). The likelihood of correct identification with CTA alone was 156/189 (82.54%) for LVOs and 65/126 (51.59%) for MeVOs. This increased to 169/189 (89.42%; p = 0.054) for LVOs and 97/126 (76.98%; p < 0.001) for MeVOs when the CTA images with CTP were viewed. There was good overall interrater agreement between readers when using CTA alone (k 0.71, 95% CI, 0.62-0.80) and almost perfect (k 0.85, 95% CI, 0.76-0.94) when CTP was added to the image for interpretation. CTA and CTP had a significantly lower median interquartile range (IQR) interpretation time than CTA alone (114 [IQR, 103-120] s vs 156 [IQR, 133-160] s, p < 0.001).

DISCUSSION

In cerebral arterial occlusions, the rate of LVO and MeVOs detections increases when adding CTP to CTA. The accuracy and time for diagnosing arterial occlusion can be significantly improved if CTP is added to CTA. As MeVOs are commonly missed by front-line neurology senior residents or stroke fellows, cases with significant deficits and no apparent arterial occlusions need to be reviewed with neuroradiological expertise.

Current neuroprotective agents in stroke

What is expected from neuroprotection is to inhibit neuronal death and halt or decelerate the neuronal loss to lower the mortality rates, decrease disability, and improve the quality of life following an acute ischemic stroke. Several agents were described as neuroprotective up to date; however, there is still debate which to use in the neurorehabilitation of stroke patients, in terms of both efficacy and also safety. In this review, we discuss the agents, citicoline, cerebrolysin and MLC901 (NeuroAiD II), the three agents which have started to be used frequently in neurorehabilitation clinics recently in the light of the current literature.

ACR Appropriateness Criteria® Cerebrovascular Diseases-Stroke and Stroke-Related Conditions

Cerebrovascular disease encompasses a vast array of conditions. The imaging recommendations for stroke-related conditions involving noninflammatory steno-occlusive arterial and venous cerebrovascular disease including carotid stenosis, carotid dissection, intracranial large vessel occlusion, and cerebral venous sinus thrombosis are encompassed by this document. Additional imaging recommendations regarding complications of these conditions including intraparenchymal hemorrhage and completed ischemic strokes are also discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Machine Meets Brain: A Systematic Review of Effectiveness of Robotically Performed Cerebral Angiography Interventions

BACKGROUND

Stroke is a leading cause of death in the United States, with significant economic and human costs. Early diagnosis and rapid treatment are critical for preventing stroke-related morbidity and mortality. However, accessibility to neurointerventional medical centers remains a challenge for many Americans, highlighting the need for innovative solutions to improve stroke management.

METHODS

This systematic review adhered to the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines and included 5 medical databases to identify relevant studies on robotically assisted cerebral angiography (RCA). Studies focusing on in-human robotic intracranial cerebral angiography were included. A bias assessment was conducted using appropriate tools for randomized controlled trials (RCTs) and non-RCTs.

RESULTS

A total of 7 studies met the inclusion criteria, with 1 RCT and 6 non-RCTs included in the analysis. Robotic systems such as CorPath GRX, Magellan robot, YDHB-NS01, VIR-2 (vascular interventional robot), and RobEnt were evaluated. The studies reported various success rates, procedure times, and complications associated with robotically assisted procedures. Overall, the robotic interventions demonstrated promising results in terms of safety and efficacy, with comparable outcomes to manual methods. Despite the promising findings, several limitations were identified, including technical issues with the robotic systems, the high costs, and limited long-term data. Future research should focus on standardizing protocols, conducting larger trials with longer follow-up periods, and assessing cost-effectiveness to determine the role of RCA in clinical practice.

CONCLUSIONS

RCA shows potential as a valuable tool in neuroendovascular interventions. Addressing the technical challenges and conducting further research will be crucial to fully realize the clinical benefits of this innovative technology and improve patient outcomes in stroke management.

Percutaneous Closure Device for the Carotid artery: An integrated review and design analysis

Endovascular thrombectomies (EVTs) are the current standard of care therapy for treating acute ischemic strokes. While access through the femoral or radial arteries is routine, up to 20% of EVTs through these sites are unable to access the cerebral vasculature on the first pass. These shortcomings are commonly due to tortuous vasculature, atherosclerotic arteries, and type III aortic arch, seen especially in the elderly population. Recent studies have shown the benefits of accessing the cerebral vasculature through a percutaneous direct carotid puncture (DCP), which can reduce the time of the procedure by half. However, current vascular closure devices (VCDs) designed for the femoral artery are not suited to close the carotid artery due to the anatomical differences. This unmet clinical need further limits a DCP approach. Thus, to foster safe adoption of this potential approach, a VCD designed specifically for the carotid artery is needed. In this review, we outline the major biomechanical properties and shortcomings of current VCDs and propose the requirements necessary to effectively design and develop a carotid closure device.

Viz LVO versus Rapid LVO in detection of large vessel occlusion on CT angiography for acute stroke

BACKGROUND

Endovascular thrombectomy improves outcomes and reduces mortality for large vessel occlusion (LVO) and is time-sensitive. Computer automation may aid in the early detection of LVOs, but false values may lead to alarm desensitization. We compared Viz LVO and Rapid LVO for automated LVO detection.

METHODS

Data were retrospectively extracted from Rapid LVO and Viz LVO running concurrently from January 2022 to January 2023 on CT angiography (CTA) images compared with a radiologist interpretation. We calculated diagnostic accuracy measures and performed a McNemar test to look for a difference between the algorithms' errors. We collected demographic data, comorbidities, ejection fraction (EF), and imaging features and performed a multiple logistic regression to determine if any of these variables predicted the incorrect classification of LVO on CTA.

RESULTS

360 participants were included, with 47 large vessel occlusions. Viz LVO and Rapid LVO had a specificity of 0.96 and 0.85, a sensitivity of 0.87 and 0.87, a positive predictive value of 0.75 and 0.46, and a negative predictive value of 0.98 and 0.97, respectively. A McNemar test on correct and incorrect classifications showed a statistically significant difference between the two algorithms' errors (P=0.00000031). A multiple logistic regression showed that low EF (Viz P=0.00125, Rapid P=0.0286) and Modified Woodcock Score >1 (Viz P=0.000198, Rapid P=0.000000975) were significant predictors of incorrect classification.

CONCLUSION

Rapid LVO produced a significantly larger number of false positive values that may contribute to alarm desensitization, leading to missed alarms or delayed responses. EF and intracranial atherosclerosis were significant predictors of incorrect predictions.

New Diagnostic Tools for Pulmonary Embolism Detection

The presentation of pulmonary embolism (PE) varies from asymptomatic to life-threatening, and management involves multiple specialists. Timely diagnosis of PE is based on clinical presentation, D-dimer testing, and computed tomography pulmonary angiogram (CTPA), and assessment by a Pulmonary Embolism Response Team (PERT) is critical to management. Artificial intelligence (AI) technology plays a key role in the PE workflow with automated detection and flagging of suspected PE in CTPA imaging. HIPAA-compliant communication features of mobile and web-based applications may facilitate PERT workflow with immediate access to imaging, team activation, and real-time information sharing and collaboration. In this review, we describe contemporary diagnostic tools, specifically AI, that are important in the triage and diagnosis of PE.

Artificial intelligence to enhance prehospital stroke diagnosis and triage: a perspective

As health systems organize to deliver the highest quality stroke care to their patients, there is increasing emphasis being placed on prehospital stroke recognition, accurate diagnosis, and efficient triage to improve outcomes after stroke. Emergency medical services (EMS) personnel currently rely heavily on dispatch accuracy, stroke screening tools, bypass protocols and prehospital notification to care for patients with suspected stroke, but novel tools including mobile stroke units and telemedicine-enabled ambulances are already changing the landscape of prehospital stroke care. Herein, the authors provide our perspective on the current state of prehospital stroke diagnosis and triage including several of these emerging trends. Then, we provide commentary to highlight potential artificial intelligence (AI) applications to improve stroke detection, improve accurate and timely dispatch, enhance EMS training and performance, and develop novel stroke diagnostic tools for prehospital use.

Robust Ensemble of Two Different Multimodal Approaches to Segment 3D Ischemic Stroke Segmentation Using Brain Tumor Representation Among Multiple Center Datasets

Ischemic stroke segmentation at an acute stage is vital in assessing the severity of patients' impairment and guiding therapeutic decision-making for reperfusion. Although many deep learning studies have shown attractive performance in medical segmentation, it is difficult to use these models trained on public data with private hospitals' datasets. Here, we demonstrate an ensemble model that employs two different multimodal approaches for generalization, a more effective way to perform on external datasets. First, after we jointly train a segmentation model on diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) MR modalities, the model is inferred on the DWI images. Second, a channel-wise segmentation model is trained by concatenating the DWI and ADC images as input, and then is inferred using both MR modalities. Before training with ischemic stroke data, we utilized BraTS 2021, a public brain tumor dataset, for transfer learning. An extensive ablation study evaluates which strategy learns better representations for ischemic stroke segmentation. In our study, nnU-Net well-known for robustness is selected as our baseline model. Our proposed method is evaluated on three different datasets: the Asan Medical Center (AMC) I and II, and the 2022 Ischemic Stroke Lesion Segmentation (ISLES). Our experiments are widely validated over a large, multi-center, and multi-scanner dataset with a huge amount of 846 scans. Not only stroke lesion models can benefit from transfer learning using brain tumor data, but combining the MR modalities using different training schemes also highly improves segmentation performance. The method achieved a top-1 ranking in the ongoing ISLES'22 challenge and performed particularly well on lesion-wise metrics of interest to neuroradiologists, achieving a Dice coefficient of 78.69% and a lesion-wise F1 score of 82.46%. Also, the method was relatively robust on the AMC I (Dice, 60.35%; lesion-wise F1, 68.30%) and II (Dice; 74.12%; lesion-wise F1, 67.53%) datasets in different settings. The high segmentation accuracy of our proposed method could improve radiologists' ability to detect ischemic stroke lesions in MRI images. Our model weights and inference code are available on https://github.com/MDOpx/ISLES22-model-inference .

Current evidence of synaptic dysfunction after stroke: Cellular and molecular mechanisms

BACKGROUND

Stroke is an acute cerebrovascular disease in which brain tissue is damaged due to sudden obstruction of blood flow to the brain or the rupture of blood vessels in the brain, which can prompt ischemic or hemorrhagic stroke. After stroke onset, ischemia, hypoxia, infiltration of blood components into the brain parenchyma, and lysed cell fragments, among other factors, invariably increase blood-brain barrier (BBB) permeability, the inflammatory response, and brain edema. These changes lead to neuronal cell death and synaptic dysfunction, the latter of which poses a significant challenge to stroke treatment.

RESULTS

Synaptic dysfunction occurs in various ways after stroke and includes the following: damage to neuronal structures, accumulation of pathologic proteins in the cell body, decreased fluidity and release of synaptic vesicles, disruption of mitochondrial transport in synapses, activation of synaptic phagocytosis by microglia/macrophages and astrocytes, and a reduction in synapse formation.

CONCLUSIONS

This review summarizes the cellular and molecular mechanisms related to synapses and the protective effects of drugs or compounds and rehabilitation therapy on synapses in stroke according to recent research. Such an exploration will help to elucidate the relationship between stroke and synaptic damage and provide new insights into protecting synapses and restoring neurologic function.

Review of Cerebral Collateral Circulation and Insight into Cardiovascular Strategies to Limit Collateral Damage in Ischemic Stroke

Cerebral collateral circulation is a dynamic and adaptive process by which alternative vascular pathways supply perfusion to ischemic brain tissue in the event of an arterial occlusion. This complicated network of blood vessels that acts as a natural bypass plays a pivotal role in stroke pathophysiology and has become a key area of study given its significance in stroke treatment and patient outcomes. In this review, we will study the factors influencing the formation, recruitment, and endurance of collateral vessels; discuss imaging modalities for quantitative and qualitative assessment of this network; explore the role of collaterals in stroke management; and highlight several cardiovascular strategies to minimize damage to collaterals and optimize stroke outcomes.

Intraoperative neuromonitoring as real-time diagnostic for cerebral ischemia in endovascular treatment of ruptured brain aneurysms

OBJECTIVE

To evaluate the diagnostic accuracy of intraoperative neurophysiological monitoring (IONM) during endovascular treatment (EVT) of ruptured intracranial aneurysms (rIA).

METHODS

IONM and clinical data from 323 patients who underwent EVT for rIA from 2014-2019 were retrospectively reviewed. Significant IONM changes and outcomes were evaluated based on visual review of data and clinical documentation.

RESULTS

Of the 323 patients undergoing EVT, significant IONM changes were noted in 30 patients (9.29%) and 46 (14.24%) experienced postprocedural neurological deficits (PPND). 22 out of 30 (73.33%) patients who had significant IONM changes experienced PPND. Univariable analysis showed changes in somatosensory evoked potential (SSEP) and electroencephalogram (EEG) were associated with PPND (p-values: <0.001 and <0.001, retrospectively). Multivariable analysis showed that IONM changes were significantly associated with PPND (Odd ratio (OR) 20.18 (95%CI:7.40-55.03, p-value: <0.001)). Simultaneous changes in both IONM modalities had specificity of 98.9% (95% CI: 97.1%-99.7%). While sensitivity when either modality had a change was 47.8% (95% CI: 33.9%-62.0%) to predict PPND.

CONCLUSIONS

Significant IONM changes during EVT for rIA are associated with an increased risk of PPND.

SIGNIFICANCE

IONM can be used confidently as a real time neurophysiological diagnostic guide for impending neurological deficits during EVT treatment of rIA.

Health Care Disparities in Stroke Rehabilitation

Stroke outcomes are influenced by factors such as education, lifestyle, and access to care, which determine the extent of functional recovery. Disparities in stroke rehabilitation research have traditionally included age, race/ethnicity, and sex, but other areas make up a gap in the literature. This article conducted a literature review of original research articles published between 2008 and 2022. The article also expands on research that highlights stroke disparities in risk factors, rehabilitative stroke care, language barriers, outcomes for stroke survivors, and interventions focused on rehabilitative stroke disparities.

Subcranial Encephalic Temnograph-Shaped Helmet for Brain Stroke Monitoring

In this contribution, a wearable microwave imaging system for real-time monitoring of brain stroke in the post-acute stage is described and validated. The system exploits multistatic/multifrequency (only 50 frequency samples) data collected via a low-cost and low-complexity architecture. Data are collected by an array of only 16 antennas moved by pneumatic system. Phantoms, built from ABS material and filled with appropriate Triton X-100-based mixtures to mimic the different head human tissues, are employed for the experiments. The microwave system exploits the differential scattering measures and the Incoherent MUSIC algorithm to provide a 3D image of the region under investigation. The shown results, although preliminary, confirm the potential of the proposed microwave system in providing reliable results, including for targets whose evolution is as small as 16 mL in volume.

Effectiveness of the acute stroke care map program in reducing in-hospital delay for acute ischemic stroke in a Chinese urban area: an interrupted time series analysis

Background

Timely intravenous thrombolysis (IVT) is crucial for improving outcomes in acute ischemic stroke (AIS) patients. This study evaluates the effectiveness of the Acute Stroke Care Map (ASCaM) initiative in Shenyang, aimed at reducing door-to-needle times (DNT) and thus improving the timeliness of care for AIS patients.

Methods

An retrospective cohort study was conducted from April 2019 to December 2021 in 30 hospitals participating in the ASCaM initiative in Shenyang. The ASCaM bundle included strategies such as EMS prenotification, rapid stroke triage, on-call stroke neurologists, immediate neuroimaging interpretation, and the innovative Pre-hospital Emergency Call and Location Identification feature. An interrupted time series analysis (ITSA) was used to assess the impact of ASCaM on DNT, comparing 9 months pre-intervention with 24 months post-intervention.

Results

Data from 9,680 IVT-treated ischemic stroke patients were analyzed, including 2,401 in the pre-intervention phase and 7,279 post-intervention. The ITSA revealed a significant reduction in monthly DNT by -1.12 min and a level change of -5.727 min post-ASCaM implementation.

Conclusion

The ASCaM initiative significantly reduced in-hospital delays for AIS patients, demonstrating its effectiveness as a comprehensive stroke care improvement strategy in urban settings. These findings highlight the potential of coordinated care interventions to enhance timely access to reperfusion therapies and overall stroke prognosis.