High prevalence of intracranial arterial stenosis among acute ischemic stroke patients in a Brazilian center: a transcranial color-coded duplex sonography study.

BACKGROUND: There is limited data available regarding the prevalence of intracranial arterial stenosis (ICAS) among acute ischemic stroke (AIS) patients in Brazil and Latin America. OBJECTIVE: The present study sought to investigate the frequency and predictors of ICAS among patients with AIS or transient ischemic attack (TIA) in a Brazilian center, with transcranial color-coded duplex sonography (TCCS) technique. METHODS: Consecutive AIS and TIA patients, admitted to an academic public comprehensive stroke center in Brazil from February to December 2014, evaluated by TCCS were prospectively selected. Vascular narrowings > 50% were considered as ICAS, based on ultrasound criteria previously defined in the literature. RESULTS: We assessed 170 consecutive patients with AIS or TIA, of whom 27 (15.9%) were excluded due to an inadequate transtemporal acoustic bone window. We confirmed ICAS in 55 patients (38.5%). The most common location was the proximal segment of the middle cerebral artery (28.2%), followed by the vertebral (15.4%), posterior cerebral (13.6%), terminal internal carotid (9.1%) and basilar (8.2%) arteries. On multivariate models adjusting for potential confounders, systolic blood pressure (OR: 1.03, 95%CI: 1.01-1.04; p = 0.008) was independently associated with ICAS. CONCLUSION: We found significant ICAS in approximately ⅓ of patients admitted with symptoms of AIS or TIA in a public tertiary academic stroke center in Brazil. The TCCS is an accessible and noninvasive technique that can be used to investigate the presence of moderate and severe ICAS, especially in patients who cannot be exposed to more invasive exams, such as the use of intravenous contrast agents.

ANTECEDENTES: Dados acerca da prevalência da estenose arterial intracraniana (EAIC) entre os pacientes com acidente vascular isquêmico (AVCi) agudo no Brasil e América Latina são limitados. OBJETIVO: O presente estudo pretendeu investigar a frequência e os preditores da EAIC nos pacientes AVCi ou ataque isquêmico transitório (AIT) em um centro brasileiro utilizando o Doppler transcraniano colorido (duplex transcraniano). MéTODOS: Pacientes consecutivos com AVCi ou AIT, admitidos entre fevereiro e dezembro de 2014 em um centro acadêmico brasileiro especializado em doenças cerebrovasculares, foram avaliados prospectivamente com duplex transcraniano. Os estreitamentos vasculares > 50% foram considerados como EAIC, baseado em critérios ultrassonográficos definidos previamente na literatura. RESULTADOS: Foram avaliados 170 pacientes com AVCi ou AIT, dos quais 27 (15,9%) foram excluídos em decorrência da janela óssea transtemporal acústica inadequada. Confirmamos EAIC em 55 pacientes (38,5%). A localização mais comum foi o segmento proximal da artéria cerebral média (28,2%), seguida pelas artérias vertebral (15,4%), cerebral posterior (13,6%), carótida interna terminal (9,1%) e basilar (8,2%). No modelo multivariado, ajustado para os potenciais confundidores, a pressão arterial sistólica aumentada (OR: 1,03; IC 95%: 1,01­1,04; p = 0,008) foi independentemente associada a EAIC. CONCLUSãO: Foi identificada EAIC significativa em quase ⅓ dos pacientes admitidos com sintomas de AVCi ou AIT em um serviço acadêmico público de atendimento especializado em doenças cerebrovasculares. O Doppler transcraniano colorido é uma ferramenta acessível e não invasiva que pode ser utilizada com segurança para a investigação da presença de EAIC moderada ou grave, especialmente nos pacientes que não podem ser expostos a exames complementares mais invasivos com uso de contraste intravenoso.

ASSESSING THE PATIENT WITH ANTIPHOSPHOLIPID SYNDROME IN LIGHT OF THE NEW 2023 ACR/EULAR ANTIPHOSPHOLIPID SYNDROME CLASSIFICATION CRITERIA - CASE REPORT.

Antiphospholipid syndrome (APS) is an acquired multisystem autoimmune disease characterized clinically by vascular thrombotic events, or pregnancy complications or nonthrombotic manifestations in the presence of persistently elevated antiphospholipid antibodies (aPL). We highlighted our case, which fulfills both the old APS classification criteria (1999,2006) _and the newest one (2023). The latest demonstrates very high specificity (99%) for APS diagnosis, compared to the older revised Sapporo criteria (86%). According to the new recommendation, the criteria are classified into 6 clinical and 2 laboratory domains, patient must accumulate at least 3 points from each clinical and laboratory domains. Our patient was diagnosed with antiphospholipid syndrome in 2018, as she had transient ischemic attack (TIA) without any changes on magnetic resonance tomography (MRI), and laboratory tests revealed triple positive antiphospholipid antibodies (12 points). Additional diagnostic tests were performed_thrombocytopenia, aortic valve thickening was noteworthy (4 points). Thus, TIA which had similar strength to stroke as the manifestation of arterial thrombosis by old guidelines, it is rejected according to the new recommendation, so the patient lost minimum 2 points; On the other hand, the current criteria added nonthrombotic events as weighted clinical domains, which gave the points to our patient. In conclusion we fully and highly specifically confirmed APS diagnosis as ACR/EULAR suggests.

Association of Acute Incidental Cerebral Microinfarcts With Subsequent Ischemic Stroke in Patients With Cancer: A Population-Based Study.

BACKGROUND AND OBJECTIVES: Incidental diffuse-weighted imaging (DWI)-positive subcortical and cortical lesions, or acute incidental cerebral microinfarcts (CMIs), are a common type of brain ischemia, which can be detected on magnetic resonance DWI for approximately 2 weeks after occurrence. Acute incidental CMI was found to be more common in patients with cancer. Whether acute incidental CMI predicts future ischemic stroke is still unknown. We aimed to examine the association between acute incidental CMI in patients with cancer and subsequent ischemic stroke or transient ischemic attack (TIA). METHODS: This is a retrospective cohort study. We used Clalit Health Services records, representing over half of the Israeli population, to identify adults with lung, breast, pancreatic, or colon cancer who underwent brain MRI between January 2014 and April 2020. We included patients who underwent scan between 1 year before cancer diagnosis and 1 year after diagnosis. Primary outcome was ischemic stroke or TIA using International Classification of Diseases, Ninth Revision codes. Secondary outcomes were intracranial hemorrhage (ICH) and mortality. Records were followed from first MRI until primary outcome, death, or end of follow-up (January 2023). Cox proportional hazards models were used to calculate hazard ratio (HR) for patients with and without acute incidental CMI, as a time-dependent covariate. RESULTS: The study cohort included 1,618 patients with cancer, among whom, 59 (3.6%) had acute incidental CMI on at least 1 brain MRI. The median (interquartile range) time from acute incidental CMI to stroke or TIA was 26 days (14-84). On multivariable analysis, patients with acute incidental CMI had a higher stroke or TIA risk (HR 2.97, 95% CI 1.08-8.18, p = 0.035) compared with their non-CMI counterparts. Acute incidental CMIs were also associated with mortality after multivariable analysis (HR 2.76, 95% CI 2.06-3.71, p < 0.001); no association with ICH was found. DISCUSSION: Acute incidental CMI on brain MRI in patients with active cancer is associated with an increased risk of near-future ischemic stroke or TIA and mortality. This finding might suggest that randomly detected acute incidental CMI in patients with cancer may guide primary cerebrovascular risk prevention and etiologic workup.

Constructing a Transient Ischemia Attack Model Utilizing Flexible Spatial Targeting Photothrombosis with Real-Time Blood Flow Imaging Feedback.

Transient ischemic attack (TIA) is an early warning sign of stroke and death, necessitating suitable animal models due to the associated clinical diagnostic challenges. In this study, we developed a TIA model using flexible spatially targeted photothrombosis combined with real-time blood flow imaging feedback. By modulating the excitation light using wavefront technology, we precisely created a square light spot (50 × 250 µm), targeted at the distal middle cerebral artery (dMCA). The use of laser speckle contrast imaging (LSCI) provided real-time feedback on the ischemia, while the excitation light was ceased upon reaching complete occlusion. Our results demonstrated that the photothrombus formed in the dMCA and spontaneously recanalized within 10 min (416.8 ± 96.4 s), with no sensorimotor deficits or infarction 24 h post-TIA. During the acute phase, ischemic spreading depression occurred in the ipsilateral dorsal cortex, leading to more severe ischemia and collateral circulation establishment synchronized with the onset of dMCA narrowing. Post-reperfusion, the thrombi were primarily in the sensorimotor and visual cortex, disappearing within 24 h. The blood flow changes in the dMCA were more indicative of cortical ischemic conditions than diameter changes. Our method successfully establishes a photochemical TIA model based on the dMCA, allowing for the dynamic observation and control of thrombus formation and recanalization and enabling real-time monitoring of the impacts on cerebral blood flow during the acute phase of TIA.

Robustness and classification capabilities of MRI radiomic features in identifying carotid plaque vulnerability.

OBJECTIVES: To assess how radiomic features may be combined with plaque morphological and compositional features identified by multi-contrast MRI to improve upon conventional risk assessment models in determining culprit carotid artery lesions. METHODS: Fifty-five patients (mean age: 62.6; 35 males) with bilateral carotid stenosis who experienced transient ischaemic attack (TIA) or stroke were included from the CARE-II multi-centre carotid imaging trial (ClinicalTrials.gov Identifier: NCT02017756). They underwent MRI within 2 weeks of the event. Classification capability in distinguishing culprit lesions was assessed by machine learning. Repeatability and reproducibility of the results were investigated by assessing the robustness of the radiomic features. RESULTS: Radiomics combined with a relatively conventional plaque morphological and compositional metric-based model provided incremental value over a conventional model alone (area under curve [AUC], 0.819 ± 0.002 vs 0.689 ± 0.019, respectively, P = .014). The radiomic model alone also provided value over the conventional model (AUC, 0.805 ± 0.003 vs 0.689 ± 0.019, respectively, P = .031). T2-weighted imaging-based radiomic features had consistently higher robustness and classification capabilities compared with T1-weighted images. Higher-dimensional radiomic features outperformed first-order features. Grey Level Co-occurrence Matrix, Grey Level Dependence Matrix, and Grey Level Size Zone Matrix sub-types were particularly useful in identifying textures which could detect vulnerable lesions. CONCLUSIONS: The combination of MRI-based radiomic features and lesion morphological and compositional parameters provided added value to the reference-standard risk assessment for carotid atherosclerosis. This may improve future risk stratification for individuals at risk of major adverse ischaemic cerebrovascular events. ADVANCES IN KNOWLEDGE: The clinical relevance of this work is that it addresses the need for a more comprehensive method of risk assessment for patients at risk of ischaemic stroke, beyond conventional stenosis measurement. This paper shows that in the case of carotid stroke, high-dimensional radiomics features can improve classification capabilities compared with stenosis measurement alone.

Anticoagulants versus Antiplatelet Treatment in the Medical Management of Carotid Floating Thrombus.

BACKGROUND: Carotid free-floating thrombus (CFT) is a rare cause of stroke describing an intraluminal thrombus that is loosely associated with the arterial wall and manifesting as a filling defect fully surrounded by flow on vascular imaging. Unfortunately, there is no clear consensus among experts on the ideal treatment for this pathology. METHODS: Retrospective analysis of acute ischemic stroke (AIS) and transient ischemic attack (TIA) patients diagnosed with CFT on computed tomography angiogram (CTA) between January 2015-March 2023. We aimed to compare two treatment regimens: anticoagulation (ACT) and antiplatelet (APT) in the treatment of CFT. APT regimens included the use of dual or single antiplatelets (DAPT or SAPT; aspirin, clopidogrel and ticagrelor) and ACT regimens included the use of direct oral anticoagulants, warfarin, heparin or low molecular weight heparin +/- ASA. Patients that underwent mechanical thrombectomy were excluded. RESULTS: During study time there were 8252 acute ischemic stroke hospitalizations, of which 135 (1.63 %) patients were diagnosed with CFT. Sixty-six patients were included in our analysis. Patients assigned to APT were older (60.41years ± 12.82;p < 0.01). Other demographic variables were similar between ACT and APT groups. Complete CFT resolution on repeat vascular imaging was numerically higher at 30 days (58.8 vs 31.6 %, respectively; p = 0.1) and at latest follow-up (70.8 vs 50 %; p = 0.1) on ACT vs APT, respectively without reaching statistical significance. Similarly, there was numerically higher rates of any ICH with ACT compared to APT but it did not achieve statistical significance (27.6 % vs 13.5 %; p = 0.5). There were similar rates of PH1/2 hemorrhagic transformation, independence at discharge and similar hospital length of stay between ACT and APT groups. Patients assigned to APT were more likely to be discharged on their assigned treatment compared to those assigned to ACT (86.5 vs 55.2 %; p < 0.001). The rate of 30-day recurrent stroke was comparable among ACT and APT at 30 days (3.4 vs 0 %; p = 0.1, respectively). Subgroup analysis comparing exclusive ACT vs Dual APT lead to similar results. CONCLUSION: Our study showed comparable efficacy and safety outcomes in CFT patients who were exclusively managed medically with ACT vs APT. Larger prospective studies are needed.

[Transient neurological deficits in a patient with chronic subdural hematoma].

A 62-year-old, right-handed man was diagnosed with asymptomatic bilateral chronic subdural hematomas and underwent hematoma removal on the left side only. At 1 month after surgery, he was admitted to our hospital because he began to have one or two attacks/day of apraxia of speech and dysesthesia of the right hand with a duration of approximately 5 |min. The left hematoma had not re-expanded, but fluid-attenuated inversion resonance imaging showed hyperintense lesions in the sulci adjacent to the hematoma. Moreover, single-photon emission computed tomography revealed low-uptake lesions in the left cerebrum adjacent to the hematoma. Electroencephalogram showed no abnormalities, and CT angiography showed a slight deviation of the left middle cerebral arteries due to the hematoma. The attacks disappeared within 10 days, although the volume of the hematoma was unchanged. It was suggested that his transient neurological deficits were caused by cerebral ischemia related to chronic subdural hematoma.

Short-term glycemic variability and intracranial atherosclerotic plaque stability assessed by high-resolution MR vessel wall imaging in type 2 diabetes mellitus.

OBJECTIVE: To investigate the relationship between short-term glycemic variability in patients with T2DM and the vulnerability of intracranial atherosclerotic plaques using HR-MR-VWI. MATERIALS AND METHODS: In total, 203 patients with acute ischemic stroke (AIS)/transient ischemia (TIA) combined with T2DM were enrolled. All of them underwent HR-MR-VWI during the period between July 2020 and July 2023. 203 patients were divided into groups with higher (1,5-AG≤ 30.7 µmol/L) and lower (1,5-AG> 30.7 µmol/L) short-term glycemic variability. Patients were also divided into the T1WI and non-T1WI hyperintensity groups. Associated factors(FBG, HbA1c, and 1,5-AG)for the T1WI hyperintensity were analyzed by binary logistic regression. We used the area under the curve (AUC), while the sensitivity and specificity were calculated at the optimal threshold. The Delong test was employed to compare the quality of the AUC of the predictors. RESULTS: The group with higher short-term glycemic variability had a higher incidence of the hyperintensity on T1WI, higher degree of enhancement, higher degree of stenosis and smaller lumen area (P < 0.05). The T1WI hyperintensity group had higher HbA1c levels, higher hemoglobin levels and lower 1,5-AG levels(P < 0.05). 1,5-AG (OR = 0.971, 95 % CI: 0.954∼0.988, P = 0.001), HbA1c (OR=1.305, 95 % CI: 1.065∼1.598, P = 0.01) and male sex (OR = 2.048, 95 % CI: 1.016∼4.128, P = 0.045)/(OR=2.102, 95 % CI: 1.058∼4.177, P = 0.034) were independent risk factors for the hyperintensity on T1WI. 1,5-AG demonstrated enhanced performance and yielded the highest AUC of the receiver operator characteristic curve (AUC = 0.726), with sensitivity and specificity values of 0.727 and 0.635 respectively. CONCLUSION: 1,5-AG, HbA1c and male sex are independent predictors of intracranial plaques with T1WI hyperintensity, the greater short-term glycemic variability, the higher incidence of vulnerable plaques.

A systematic review of the incidence and outcomes of ICD-11 defined stroke.

BACKGROUND: The World Health Organisation has expanded the definition of stroke to include people with symptoms less than 24 h if they have evidence of stroke on neuroimaging. The impact is that people previously diagnosed as having a transient ischaemic attack (TIA) would now be considered to have had a stroke. This change will impact incidence and outcomes of stroke and increase eligibility for secondary prevention. We aimed to evaluate the new ICD-11 criteria retrospectively to previous TIA studies to understand the change in incidence and outcomes of this type of stroke. METHODS: We conducted a systematic review of observational studies of the incidence and outcomes of clinically defined TIA. We searched PubMed, EMBASE, and Google Scholar from inception to 23rd May 2023. Study quality was assessed using a risk of bias tool for prevalence studies. FINDINGS: Our review included 25 studies. The rate of scan positivity for stroke among those with clinically defined TIA was 24 %, (95 % CI, 16-33 %) but with high heterogeneity (I2 = 100 %, p <0.001). Sensitivity analyses provided evidence that heterogeneity could be explained by methodology and recruitment method. The scan positive rate when examining only studies at low risk of bias was substantially lower, at 13 % (95 % CI, 11-15 %, I2 = 0, p = 0.77). We estimate from population-based incidence studies that ICD-11 would result in an increase stroke incidence between 4.8 and 10.5 per 100,000 persons/year. Of those with DWI-MRI evidence of stroke, 6 % (95 % CI, 3-11 %) developed a recurrent stroke in the subsequent 90 days, but with substantial heterogeneity (I2 = 67 %, p = 0.02). CONCLUSION: The impact of the ICD-11 change in stroke definition on incidence and outcomes may have been overestimated by individual studies. Community-based stroke services with access to DWI MRI are likely to accurately diagnose greater numbers of people with mild ICD-11 stroke, increasing access to effective prevention.

Alcohol consumption may be a risk factor for cerebrovascular stenosis in acute ischemic stroke and transient ischemic attack.

BACKGROUND: Atherosclerosis are well established risk factors for ischemic stroke, however the association between alcohol consumption and atherosclerosis is controversial. This study aims to explore the potential correlation between alcohol consumption and cerebral stenosis in patients with acute ischemic stroke and transient ischemic attack (TIA). METHODS: Nine hundreds and eighty-eight patients with first acute ischemic stroke attack or TIA were recruited retrospectively. Alcohol consumption was classified into five consumption categories (non-drinkers, occasional drinkers, < 140 g per week [mild drinkers], 140-279 g per week [moderate drinkers], ≥ 280 g per week [heavy drinkers]). Computed tomography angiography (CTA) and digital subtraction angiography (DSA) were utilized to assess the carotid and cerebral artery in all patients. Five-step scale for degree of stenosis was applied: normal (0, 0 points), mild (< 50%, 1 point), moderate (50-69%, 2 points), severe (70-99%, 3 points), and occlusion (100%, 4 points). RESULTS: The carotid and cerebral artery stenosis scores were positively correlated with moderate alcohol consumption (B = 1.695, P < 0.001). Compared with nondrinkers, moderate alcohol consumption had significant increasing risk of moderate carotid and cerebral artery stenosis (OR = 4.28, 95% CI: 1.47-12.49, P = 0.008) and severe stenosis (OR = 4.24, 95% CI: 1.55-11.64, P = 0.005) and occlusion (OR = 3.87, 95% CI: 1.65-9.06, P = 0.002). Compared with nondrinkers, heavy alcohol consumption patients had significant higher risk of carotid and cerebral artery occlusion (OR = 2.71, 95% CI: 1.36-5.41, P = 0.005). CONCLUSIONS: Higher alcohol consumption may associate with higher risk and more severity of carotid and cerebrovascular stenosis.

Allopurinol and blood pressure variability following ischemic stroke and transient ischemic attack: a secondary analysis of XILO-FIST.

Blood Pressure Variability (BPV) is associated with cardiovascular risk and serum uric acid level. We investigated whether BPV was lowered by allopurinol and whether it was related to neuroimaging markers of cerebral small vessel disease (CSVD) and cognition. We used data from a randomised, double-blind, placebo-controlled trial of two years allopurinol treatment after recent ischemic stroke or transient ischemic attack. Visit-to-visit BPV was assessed using brachial blood pressure (BP) recordings. Short-term BPV was assessed using ambulatory BP monitoring (ABPM) performed at 4 weeks and 2 years. Brain MRI was performed at baseline and 2 years. BPV measures were compared between the allopurinol and placebo groups, and with CSVD and cognition. 409 participants (205 allopurinol; 204 placebo) were included in the visit-to-visit BPV analyses. There were no significant differences found between placebo and allopurinol groups for any measure of visit-to-visit BPV. 196 participants were included in analyses of short-term BPV at week 4. Two measures were reduced by allopurinol: the standard deviation (SD) of systolic BP (by 1.30 mmHg (95% confidence interval (CI) 0.18-2.42, p = 0.023)); and the average real variability (ARV) of systolic BP (by 1.31 mmHg (95% CI 0.31-2.32, p = 0.011)). There were no differences in other measures at week 4 or in any measure at 2 years, and BPV was not associated with CSVD or cognition. Allopurinol treatment did not affect visit-to-visit BPV in people with recent ischemic stroke or TIA. Two BPV measures were reduced at week 4 by allopurinol but not at 2 years.

Evaluation of the Correlation Between Distribution Location and Vulnerability of Carotid Plaque in Patients with Transient Ischemic Attack.

Purpose: To analyze the relationship among distribution location, characteristics, and vulnerability of carotid plaque using CTA and provide more information on the risk factors of carotid atherosclerotic plaque. Patients and Methods: We retrospectively analyzed the CTA images of the head and neck of 93 patients with carotid atherosclerosis. Atherosclerosis was developed in 148 carotid arteries. The plaques were divided into a high-risk plaque group and a low-risk plaque group according to whether the plaques had high-risk characteristics. The maximum cross-sectional area of carotid artery bifurcation plaque on the axial image was selected, and the cross-sectional lumen was equally divided into four 90-degree sectors, ventral side wall, dorsal side wall, inner side wall, and outer side wall. The differences in the characteristics and distribution locations of the plaques in the two groups were analyzed. The characteristic parameters of the cross-sectional plaques at the bifurcation of the carotid artery. The logistic regression analysis was used to further analyze the risk factors associated with plaque vulnerability. Results: Among 148 carotid arteries,80 were classified as high-risk and 68 as low-risk groups. There were significant differences between the two groups concerning the thickness, length, maximum cross-sectional area, burden, and cross-sectional distribution of the plaques (P < 0.05). The plaque distribution on the dorsal side wall of the carotid bifurcation was higher in the high-risk group than that in the low-risk group (P < 0.05), dorsal side wall plaque-independent risk factors for the development of vulnerability of plaques in transient ischemic attack (TIA) patients (95% CI:1.522~6.991, P<0.05). Conclusion: High-risk plaques tend to occur on the dorsal side wall of the carotid bifurcation, whereas low-risk plaques tend to occur on the outer side wall of the carotid bifurcation.

Magnetic Resonance Imaging Assists With Determining Etiology After Transient Ischemic Attack or Minor Stroke.

BACKGROUND: Magnetic resonance imaging infarct topography may assist with determining stroke etiology. The influence of diffusion-weighted imaging (DWI)-positive lesions on etiology determination in patients with transient ischemic attack or minor stroke is not well studied. METHODS AND RESULTS: We prospectively enrolled patients between 2010 and 2017 in 2 studies; participants with a final diagnosis of probable or definite transient ischemic attack or stroke were pooled for analysis. The primary outcome was the adjudicated ischemic etiology. We compared proportion of each etiology (cardioembolic, large-vessel, small-vessel disease, other) in patients who had DWI positivity compared with DWI negativity. We used logistic regression to determine the adjusted odds ratio (OR) for each etiology compared with undetermined by DWI positivity. The final analysis included 1498 patients: 832 (55.5%) were DWI-positive. DWI-positive patients were more likely to be diagnosed with small-vessel disease (19.1% versus 5.3%) and less likely with undetermined etiology (36.9% versus 53.0%; P<0.001). After adjustment, the presence of any DWI lesion was associated with increased odds of assigning any etiology (OR, 1.8 [95% CI, 1.3-2.5]). A single DWI lesion was associated with increased odds of small-vessel disease diagnosis (OR, 9.5 [95% CI, 6.4-14.0]), and multiple DWI lesions with reduced odds of small-vessel disease (OR, 0.2 [95% CI, 0.1-0.4]) but increased odds of all other etiologies compared with undetermined etiology. CONCLUSIONS: Any DWI-positive lesion after suspected transient ischemic attack or minor stroke was associated with increased odds of assigning a etiology. Presence and topography of DWI lesions on magnetic resonance imaging may assist with etiology determination and may impact stroke prevention therapies.

Measurement of optic nerve sheath diameter on computed tomography for the differentiation of transient ischemic attacks.

OBJECTIVE: The objective of this study was to investigate whether the measurement of mean optic nerve sheath diameter in patients with transient ischemic attack could be used to distinguish between control groups, the acute ischemic stroke group, and subgroups within the acute ischemic stroke category. METHODS: Retrospectively, the mean optic nerve sheath diameters of patients aged 18 years and older belonging to control, transient ischemic attack, acute ischemic stroke, and subgroups within the acute ischemic stroke category were measured with initial computed tomography conducted in the emergency department. RESULTS: Out of the 773 patients included in the study, 318 (41.1%) were in the control group, 77 (10%) had transient ischemic attack, and 378 (49%) were categorized as stroke patients. The average mean optic nerve sheath diameter was significantly higher in both the stroke and transient ischemic attack groups compared with the control group (p<0.001 for both comparisons). Furthermore, the mean optic nerve sheath diameter in the stroke subgroups was significantly higher than in both the transient ischemic attack and control groups (p<0.001 for all comparisons). In transient ischemic attack patients, the mean optic nerve sheath diameter showed a significant ability to predict transient ischemic attack (AUC=0.913, p<0.001), with a calculated optimal cutoff value of 4.72, sensitivity of 94.8%, and specificity of 73.9%. CONCLUSION: The mean optic nerve sheath diameter of patients in the transient ischemic attack group was lower compared with those in the stroke subgroups but higher compared with the control group.

Impact of early MRI in ischemic strokes beyond hyper-acute stage to improve patient outcomes, enable early discharge, and realize cost savings.

BACKGROUND: Early in-patient MR Imaging may assist in identifying stroke etiology, facilitating prompt secondary prevention for ischemic strokes (IS), and potentially enhancing patient outcomes. This study explores the impact of early in patient MRI on IS patient outcomes and healthcare resource use beyond the hyper-acute stage. METHODS: In this retrospective registry-based study, 771 admitted transient ischemic attack (TIA) and IS patients at Halifax's QEII Health Centre from 2015 to 2019 underwent in-patient MRI. Cohort was categorized into two groups based on MRI timing: early (within 48 h) and late. Logistic regression and Poisson log-linear models, adjusted for age, sex, stroke severity, acute stroke protocol (ASP) activation, thrombolytic, and thrombectomy, were employed to examine in-hospital, discharge, post-discharge, and healthcare resource utilization outcomes. RESULTS: Among the cohort, 39.6 % received early in-patient MRI. ASP activation and TIA were associated with a higher likelihood of receiving early MRI. Early MRI was independently associated with a lower rate of symptomatic changes in neurological status during hospitalization (adjusted odds ratio [OR], 0.42; 95 % confidence interval [CI], 0.20-0.88), higher odds of good functional outcomes at discharge (1.55; 1.11-2.16), lower rate of non-home discharge (0.65; 0.46-0.91), shorter length of stay (regression coefficient, 0.93; 95 % CI, 0.89-0.97), and reduced direct cost of hospitalization (0.77; 0.75-0.79). CONCLUSION: Early in-patient MRI utilization in IS patients post-hyper-acute stage was independently associated with improved patient outcomes and decreased healthcare resource utilization, underscoring the potential benefits of early MRI during in-patient management of IS. Further research, including randomized controlled trials, is warranted to validate these findings.

Long-term recurrence of ischemic events in patients with intracranial atherosclerotic stenosis stratified by symptoms and pathogenesis.

BACKGROUND: Intracranial atherosclerotic stenosis (ICAS) can cause either transient ischemic attack (TIA) or acute ischemic stroke (AIS). Pathogenesis of ICAS-AIS can be divided into artery-to-artery embolism(A-A), hypoperfusion(HP), and parent-artery atherosclerosis occluding penetrating artery(POPA). However, the prognosis of each type remains uncertain. Our study aimed to investigate potential disparities in the recurrent risk among these four subtypes of symptomatic ICAS. METHODS: From a prospective, single-center cohort study of acute cerebrovascular diseases from January 2017 to November 2021, we recruited 120 ICAS patients and classified them into four groups based on diffusion weighted imaging. Patients were retrospectively followed up for recurrence in December 2022. The primary outcome was recurrent cerebral vascular events (RCVE) in the same territory. RESULTS: Among 120 recruited patients, POPA(33%) was the most common subtype, followed by A-A(32%), HP(29%), and TIA(6%). Cumulative recurrent rate was 31.2% with median months of follow-up as 27(20-45.5). There was no significant difference in the risk of RCVE in the same territory among four subgroups within three months. However, when considering the risk after three months, TIA(57%) had the highest risk of RCVE, followed by A-A(26%), while HP(4%) and POPA(8%) had lower risks (P = 0.001). Cox regression model indicated that symptom and pathogenesis was an independent risk factor for RCVE in long-term prognosis (P = 0.022), after adjusting for a history of hypertension and cerebral infarction. CONCLUSIONS: Distinctive symptoms and pathogenesis of ICAS exhibit varying risks of RCVE in long-term prognosis. The differentiation in recurrent risk may provide valuable insights for guiding secondary prevention strategies.

Clinical Associations and Prognostic Value of MRI-Visible Perivascular Spaces in Patients With Ischemic Stroke or TIA: A Pooled Analysis

BACKGROUND AND OBJECTIVES: Visible perivascular spaces are an MRI marker of cerebral small vessel disease and might predict future stroke. However, results from existing studies vary. We aimed to clarify this through a large collaborative multicenter analysis. METHODS: We pooled individual patient data from a consortium of prospective cohort studies. Participants had recent ischemic stroke or transient ischemic attack (TIA), underwent baseline MRI, and were followed up for ischemic stroke and symptomatic intracranial hemorrhage (ICH). Perivascular spaces in the basal ganglia (BGPVS) and perivascular spaces in the centrum semiovale (CSOPVS) were rated locally using a validated visual scale. We investigated clinical and radiologic associations cross-sectionally using multinomial logistic regression and prospective associations with ischemic stroke and ICH using Cox regression. RESULTS: We included 7,778 participants (mean age 70.6 years; 42.7% female) from 16 studies, followed up for a median of 1.44 years. Eighty ICH and 424 ischemic strokes occurred. BGPVS were associated with increasing age, hypertension, previous ischemic stroke, previous ICH, lacunes, cerebral microbleeds, and white matter hyperintensities. CSOPVS showed consistently weaker associations. Prospectively, after adjusting for potential confounders including cerebral microbleeds, increasing BGPVS burden was independently associated with future ischemic stroke (versus 0-10 BGPVS, 11-20 BGPVS: HR 1.19, 95% CI 0.93-1.53; 21+ BGPVS: HR 1.50, 95% CI 1.10-2.06; p = 0.040). Higher BGPVS burden was associated with increased ICH risk in univariable analysis, but not in adjusted analyses. CSOPVS were not significantly associated with either outcome. DISCUSSION: In patients with ischemic stroke or TIA, increasing BGPVS burden is associated with more severe cerebral small vessel disease and higher ischemic stroke risk. Neither BGPVS nor CSOPVS were independently associated with future ICH.

The mid-term results of the Carotid Asymptomatic Stenosis (CARAS) observational study.

INTRODUCTION: Carotid endarterectomy (CEA) in patients with asymptomatic carotid stenosis (ACAS) remains a subject of debate. Current recommendations are based on randomized trials conducted over 20 years ago and improvements in medical therapies may have reduced the risk of cerebral ischemic events (CIE). This study presents a mid-term analysis of results from an ongoing prospective observational study of ACAS patients to assess their CIE risk in a real-world setting. METHODS: This is a prospective observational cohort study of patients with ACAS >60 % (NASCET criteria) identified in a single duplex ultrasonography (DUS) vascular laboratory (trial registered: NCT04825080). Patients were not considered for CEA due to their short life expectancy (<3 year) or absence of signs of plaque vulnerability (ulceration, ipoechogenic core). Patient enrollment started in January 2019 and ended in March 2020 with a targeted sample size of 300 patients.A 5-year follow-up was scheduled. Clinical characteristics, risk factors, and medical therapies were documented, and, when necessary, the best medical therapy (BMT), involving antiplatelet agents, blood pressure control, and statins, was recommended during clinical visits. The primary endpoint was to asses CIEs (including strokes, transient ischemic attacks, amaurosis-fugax) ipsilateral to ACAS along with plaque progression rate and patients survival. Follow-up involved annual clinical visit and carotid DUS examination, complemented by telephone interviews at six-month intervals. RESULTS: The study included 307 patients, with an average age of 80 ± 7 years, of whom 55 % were male. Contralateral stenosis exceeding 60 % was present in 61 (20 %) patients. Seventy-seven percent of patients were on BMT. At a mean follow-up of 41±9 months, 7 ispilateral strokes and 9 TIAs occurred, resulting in 14 CIEs (2 patients experienced both TIA and stroke). According to Kaplan-Meier analysis, the 4-year CIE rate was 6±2 %, with an annual CIE rate of 1.5 %. Fifty-eight (19 %) patients had a stenosis progression which was associated with a higher 4-year estimated CIE rate compared to patients with stable plaque (10.3 % vs 3.2 %, P=.01). Similarly, a contralateral carotid stenosis >60 % was associated with a higher 4-year estimated CIE rate: 11.7 % vs 2.9 %, P=.002. These factors were independently associated with high risk for CIE at the multivariate COX analysis: Hazard Ratio (HR): 3.2; 95 % Confidence Interval: 1.1-9.2 and HR: 3.6; 95 % CI: 1.2-10.5. CONCLUSION: The mid-term results of this prospective study suggest that the incidence of CIE in ACAS patients should not be underestimated, with plaque progression and contralateral stenosis serving as primary predictors of CIEs.

The Utility of Echocardiogram in the Workup of Ischemic Stroke Patients.

BACKGROUND: Cardiac sources of emboli can be identified by transthoracic echocardiogram (TTE). The Canadian Best Practice Guidelines recommend routine use of TTE in the initial workup of ischemic stroke when an embolic source is suspected. However, TTEs are commonly ordered for all patients despite insufficient evidence to justify cost-effectiveness. We aim to evaluate the TTE ordering pattern in the initial workup of ischemic stroke at a regional Stroke Center in Central South Ontario and determine the proportion of studies which led to a change in management and affected length of stay (LOS). METHODS: Hospital records of 520 patients with a discharge diagnosis of TIA or ischemic stroke between October 2016 and June 2017 were reviewed to gather information. RESULTS: 477 patients admitted for TIA or ischemic stroke met inclusion criteria. 67.9% received TTE, out of which 6.0% had findings of cardiac sources of emboli including left ventricular thrombus, atrial septal aneurysm, PFO, atrial myxoma, and valvular vegetation. 2.5% of all TTE findings led to change in medical management. The median LOS of patients who underwent TTE was 2 days longer (p < 0.00001). CONCLUSION: TTE in the initial workup of TIA or ischemic stroke remains common practice. The yield of TTEs is low, and the proportion of studies that lead to changes in medical management is minimal. TTE completion was associated with increased LOS and may result in increased healthcare spending; however, additional factors prolonging the LOS could not be excluded.

A new predictor of coronary artery disease in acute ischemic stroke or transient ischemic attack patients: pericarotid fat density.

OBJECTIVES: The study aims to evaluate the incremental predictive value of pericarotid fat density (PFD) on head and neck computed tomography angiography (CTA) for the obstructive coronary artery disease (CAD) (≥ 50% stenosis) relative to a clinical risk model (Framingham risk score (FRS)) and the degree of carotid artery stenosis and plaque type in acute ischemic stroke (AIS) or transient ischemic attack (TIA) patients without a known history of CAD. METHODS: In a cohort of 134 consecutive stable patients diagnosed with AIS or TIA undergoing head and neck CTA between January 2010 and December 2021, pericarotid adipose tissue density (PFD) was quantified using a dedicated software. We collected demographic and clinical data, assessed the risk of CAD using the FRS, and analyzed coronary and carotid artery CTA images. Univariate and multivariate logistic regression analyses were performed to assess associations between FRS, PFD, CTA variables, and obstructive CAD risk. Four prediction models were established to evaluate the incremental predictive value of PFD relative to FRS, stenosis degree, and plaque types. Receiver operating characteristic (ROC) curves were generated, and the areas under the curves (AUC) were compared. RESULTS: Increasing FRS, stenosis degree, and PFD values were positively correlated with obstructive CAD (all p < 0.05). In the predictive models for obstructive CAD, the model incorporating carotid stenosis exhibited superior predictive performance compared to FRS alone (p < 0.05). Moreover, the predictive model integrating PFD demonstrated enhanced performance and yielded the highest AUC of the receiver operator characteristic curve (AUC = 0.783), with sensitivity and specificity values of 86.89% and 65.75%, respectively. CONCLUSION: CTA-derived PFD measurements offer supplementary predictive value for obstructive CAD beyond FRS and stenosis, thereby facilitating improved risk stratification of TIA or stroke patients without a history of CAD history. CLINICAL RELEVANCE STATEMENT: CTA-derived PFD provides incremental predictive value for obstructive coronary artery disease in acute ischemic stroke or transient ischemic attack patients without CAD history, beyond Framingham risk score and carotid artery stenosis degree, improving risk stratification. KEY POINTS: • Pericarotid fat density is associated with obstructive coronary artery disease in acute ischemic stroke or transient ischemic attack patients. • Higher pericarotid fat density corresponds to an increased risk of obstructive coronary artery disease. • Estimation of pericarotid fat density using computed tomography angiography imparts additional predictive value for obstructive CAD in risk stratification of acute ischemic stroke or transient ischemic attack patients.