Differences in Ischemic Anterior and Posterior Circulation Strokes: A Clinico-Radiological and Outcome Analysis

Deep learning model integrating radiologic and clinical data to predict mortality after ischemic stroke

Objective

Most prognostic indexes for ischemic stroke mortality lack radiologic information. We aimed to create and validate a deep learning-based mortality prediction model using brain diffusion weighted imaging (DWI), apparent diffusion coefficient (ADC), and clinical factors.

Methods

Data from patients with ischemic stroke who admitted to tertiary hospital during acute periods from 2013 to 2019 were collected and split into training (n = 1109), validation (n = 437), and internal test (n = 654). Data from patients from secondary cardiovascular center was used for external test set (n = 507). The algorithm for predicting mortality, based on DWI and ADC (DLP_DWI), was initially trained. Subsequently, important clinical factors were integrated into this model to create the integrated model (DLP_INTG). The performance of DLP_DWI and DLP_INTG was evaluated by using time-dependent area under the receiver operating characteristic curves (TD AUCs) and Harrell concordance index (C-index) at one-year mortality.

Results

The TD AUC of DLP_DWI was 0.643 in internal test set, and 0.785 in the external dataset. DLP_INTG had a higher performance at predicting one-year mortality than premise score in internal dataset (TD- AUC: 0.859 vs. 0.746; p = 0.046), and in external dataset (TD- AUC: 0.876 vs. 0.808; p = 0.007). DLP_DWI and DLP_INTG exhibited strong discrimination for the high-risk group for one-year mortality.

Interpretation

A deep learning model using brain DWI, ADC and the clinical factors was capable of predicting mortality in patients with ischemic stroke.

Utilizing machine learning to facilitate the early diagnosis of posterior circulation stroke

BACKGROUND

Posterior Circulation Syndrome (PCS) presents a diagnostic challenge characterized by its variable and nonspecific symptoms. Timely and accurate diagnosis is crucial for improving patient outcomes. This study aims to enhance the early diagnosis of PCS by employing clinical and demographic data and machine learning. This approach targets a significant research gap in the field of stroke diagnosis and management.

METHODS

We collected and analyzed data from a large national Stroke Registry spanning from January 2014 to July 2022. The dataset included 15,859 adult patients admitted with a primary diagnosis of stroke. Five machine learning models were trained: XGBoost, Random Forest, Support Vector Machine, Classification and Regression Trees, and Logistic Regression. Multiple performance metrics, such as accuracy, precision, recall, F1-score, AUC, Matthew's correlation coefficient, log loss, and Brier score, were utilized to evaluate model performance.

RESULTS

The XGBoost model emerged as the top performer with an AUC of 0.81, accuracy of 0.79, precision of 0.5, recall of 0.62, and F1-score of 0.55. SHAP (SHapley Additive exPlanations) analysis identified key variables associated with PCS, including Body Mass Index, Random Blood Sugar, ataxia, dysarthria, and diastolic blood pressure and body temperature. These variables played a significant role in facilitating the early diagnosis of PCS, emphasizing their diagnostic value.

CONCLUSION

This study pioneers the use of clinical data and machine learning models to facilitate the early diagnosis of PCS, filling a crucial gap in stroke research. Using simple clinical metrics such as BMI, RBS, ataxia, dysarthria, DBP, and body temperature will help clinicians diagnose PCS early. Despite limitations, such as data biases and regional specificity, our research contributes to advancing PCS understanding, potentially enhancing clinical decision-making and patient outcomes early in the patient's clinical journey. Further investigations are warranted to elucidate the underlying physiological mechanisms and validate these findings in broader populations and healthcare settings.

Intravenous Thrombolysis in Posterior versus Anterior Circulation Stroke: Clinical Outcome Differs Only in Patients with Large Vessel Occlusion

The safety and efficacy of intravenous thrombolysis (IVT) are well established in anterior circulation stroke (ACS) but are much less clear for posterior circulation stroke (PCS). The aim of this study was to evaluate the occurrence of parenchymal hematoma (PH) and 3-month clinical outcomes after IVT in PCS and ACS. In an observational, cohort multicenter study, we analyzed data from ischemic stroke patients treated with IVT prospectively collected in the SITS (Safe Implementation of Treatments in Stroke) registry in the Czech Republic between 2004 and 2018. Out of 10,211 patients, 1166 (11.4%) had PCS, and 9045 (88.6%) ACS. PH was less frequent in PCS versus ACS patients: 3.6 vs. 5.9%, odds ratio (OR) = 0.594 in the whole set, 4.4 vs. 7.8%, OR = 0.543 in those with large vessel occlusion (LVO), and 2.2 vs. 4.7%, OR = 0.463 in those without LVO. At 3 months, PCS patients compared with ACS patients achieved more frequently excellent clinical outcomes (modified Rankin scale [mRS] 0-1: 55.5 vs. 47.6%, OR = 1.371 in the whole set and 49.2 vs. 37.6%, OR = 1.307 in those with LVO), good clinical outcomes (mRS 0-2: 69.9 vs. 62.8%, OR = 1.377 in the whole set and 64.5 vs. 50.5%, OR = 1.279 in those with LVO), and had lower mortality (12.4 vs. 16.6%, OR = 0.716 in the whole set and 18.4 vs. 25.5%, OR = 0.723 in those with LVO) (p < 0.05 in all cases). In PCS versus ACS patients, an extensive analysis showed a lower risk of PH both in patients with and without LVO, more frequent excellent and good clinical outcomes, and lower mortality 3 months after IVT in patients with LVO.

Revascularization of arterial occlusions in posterior circulation acute ischemic stroke

PURPOSE OF REVIEW

This review highlights the latest advancements achieved in the revascularization of arterial occlusions associated with an acute ischemic stroke affecting the posterior circulation. It delves into the frequency and outcomes based on specific arterial segments and presents current evidence supporting revascularization treatments, including intravenous thrombolysis and endovascular thrombectomy.

RECENT FINDINGS

Comprehensive evidence for treatment across major arterial segments of the posterior circulation -- vertebral artery, basilar artery, posterior cerebral artery, cerebellar arteries, and multilevel posterior occlusions -- is provided. Additionally, the latest findings from randomized clinical trials on basilar artery occlusion are explored alongside results from extensive retrospective analyses of isolated vertebral and posterior cerebral artery occlusions.

SUMMARY

Current research supports the treatment decision in acute ischemic strokes of the posterior circulation using both intravenous thrombolysis and endovascular thrombectomy. This review also emphasizes existing knowledge gaps in the management of these strokes and advocates for more randomized clinical trials, notably concerning the posterior cerebral artery (currently ongoing), isolated vertebral artery, and multilevel posterior circulation occlusions.

Subtyping treatment response of tirofiban in acute ischemic stroke based on neuroimaging features

In a previously published clinical trial, we demonstrated that tirofiban was effective and safe in acute ischemic stroke (AIS) patients who did not undergo early recanalization treatments. We aimed to evaluate neuroimaging characteristics and their clinical significance to guide tirofiban treatment. In this post hoc analysis, location of infarcts (anterior circulation stroke [ACS] vs. posterior circulation stroke [PCS]), degree of cerebral artery stenosis (≤69% vs. ≥70% or occlusion), total infarct volume, and ASPECTS were used to predict the treatment effects of tirofiban, defined as the proportions of excellent and favorable functional outcome (modified Rankin Scale [mRS] score of 0-1, 0-2) at 90 days. ACS patients were more likely to achieve excellent (OR 2.08; 95% CI 1.25-3.45; p = 0.004) and favorable functional outcome (OR 2.28; 95% CI 1.24-4.22; p = 0.008) when treated with tirofiban. However, there was no significant difference in PCS patients between tirofiban and the control group. For patients with severe stenosis (≥70% or occlusion), tirofiban treatment improved the proportion of good outcomes (OR 2.84; 95% CI 1.44-5.60; p = 0.002 for mRS 0-1; OR 2.42; 95% CI 1.22-4.77; p = 0.011 for mRS 0-2). Meanwhile, we found that tirofiban improved outcome in patients with ASPECTS 8-10 and was independent of total infarct volume. These findings support the hypothesis that patients with ACS and severe stenosis may be recommended for tirofiban treatment, which can be predicted independent of total infarct volume.

Posterior circulation cerebral infarction: A review of clinical, imaging features, management, and outcomes

Objective

This narrative review discusses posterior circulation cerebral infarcts (PCCI) and provides an update given recent randomized trials in the management of basilar artery occlusion (BAO). We examine clinical characteristics, imaging protocols, management updates, and outcomes of PCCI.

Methods

The following databases were searched: MEDLINE, Scopus, Google Scholar, and Web of Science for articles on PCCI. We included randomized trials and observational studies in humans. We also reviewed relevant references from the literature identified.

Results

PCCI and BAO is associated with high morbidity and mortality. Early assessment and accurate diagnosis of PCCI remains a clinical challenge. Neuroimaging advances have improved early detection, but barriers remain due to costs and availability. Recent randomized trials provide new insights for BAO patients and support the efficacy of endovascular thrombectomy.

Discussion

PCCI requires specific diagnostic and management that is distinct from anterior circulation stroke. While further studies are needed in varied populations and in the subset of BAO patients presenting with milder deficits, growing randomized data support the treatment of BAO patients with endovascular thrombectomy.

Sex differences in acute ischemic stroke presentation are a matter of infarct location

INTRODUCTION

Recognition of stroke by Emergency Medical Services (EMS) is critical to initiate rapid emergency department treatment. Most prehospital stroke screening tools rely heavily on presentation with the classic symptoms of facial droop, speech changes, unilateral weakness. However, women may be less likely to present with classic symptoms and may also have different distributions of stroke by anatomical location. This study seeks to determine the association between biological sex, presentation with classic symptoms, and the location of the infarcted tissue.

METHODS

This is a retrospective cohort study. Data from electronic health records were extracted for patients with acute ischemic stroke who presented via EMS to a single Comprehensive Stroke Center between January 1, 2018 and December 31, 2020. We used descriptive statistics characterize the cohort. Multivariable logistic regression identified factors associated with classic symptom presentation (facial droop, speech changes, and/or unilateral weakness). Biological sex, location of the infarct, stroke etiology, age and the interaction between sex and infarct location were assessed as covariates.

RESULTS

There were 364 (58.6%) males and 257 (41.1%) females with an acute ischemic stroke included in this study. EMS documented one or more classic symptoms in 125 (72.3%) males and 161 (67.9%) females. There were no baseline differences in infarct location or presentation with classic symptoms as documented by EMS comparing males and females. Multivariate logistic regression found no association between biological sex and presentation with classic symptoms (Odds Ratio 1.08; 95% CI 0.58 to 1.55) after controlling for age, stroke location, etiology of stroke or the interaction between sex and infarct location. Presence of an anterior circulation infarct compared to posterior circulation infarct was positively associated with a classic presentation to EMS (Odds Ratio 3.41; 95% CI 2.15 to 5.41).

CONCLUSIONS

This study found no difference in the frequency of patient presentation with classic stroke symptoms based on biological sex alone, nor a significant different in distribution of infarcts between males and females. Infarct location (i.e., involving the anterior circulation) was associated with a classic presentation. This suggests that the likelihood of presenting with classic stroke symptoms is not influenced by sex, but rather the location of the infarct.

Pearls for the Emergency Clinician: Posterior Circulation Stroke

BACKGROUND

Posterior circulation (PC) stroke in adults is a rare, frequently misdiagnosed, serious condition that carries a high rate of morbidity.

OBJECTIVE OF THE REVIEW

This review evaluates the presentation, diagnosis, and management of PC stroke in the emergency department (ED) based on current evidence.

DISCUSSION

PC stroke presents most commonly with dizziness or vertigo and must be distinguished from more benign diagnoses. Emergency clinicians should consider this condition in patients with dizziness, even in younger patients and those who do not have traditional stroke risk factors. Neurologic examination for focal neurologic deficit, dysmetria, dysarthria, ataxia, and truncal ataxia is essential, as is the differentiation of acute vestibular syndrome vs. spontaneous episodic vestibular syndrome vs. triggered episodic vestibular syndrome. The HINTS (head impulse, nystagmus, and test of skew) examination can be useful for identifying dizziness presentations concerning for stroke when performed by those with appropriate training. However, it should only be used in patients with continuous dizziness who have ongoing nystagmus. Contrast tomography (CT), CT angiography, and CT perfusion have limited sensitivity for identifying PC strokes, and although magnetic resonance imaging is the gold standard, it may miss some PC strokes early in their course. Thrombolysis is recommended in patients presenting within the appropriate time window for thrombolytic therapy, and although some data suggest endovascular therapy for basilar artery and posterior cerebral artery infarcts is beneficial, its applicability for all PC strokes remains to be determined.

CONCLUSIONS

An understanding of PC stroke can assist emergency clinicians in diagnosing and managing this disease.

The Efficacy and Safety of Mechanical Thrombectomy in Posterior Circulation Large Vessel Occlusion as Compared to Anterior Circulation Large Vessel Occlusion: A Systematic Review

Mechanical thrombectomy (MT) has been established as a standard of care for patients with stroke due to anterior circulation large vessel occlusion (AC-LVO). Due to a lack of robust evidence for the effectiveness of mechanical thrombectomy, intravenous thrombolysis (IVT) is still the only approved first-line acute reperfusion strategy for posterior circulation large vessel occlusion (PC-LVO). This systematic review analyzes and reports on the effectiveness and safety of MT in PC-LVO. A literature review was performed to identify all studies of patients with acute ischemic stroke due to PC-LVO who underwent MT with second-generation devices (stent retrievers and/or aspiration devices) that were reported between January 2017 and January 2023. The primary outcome was functional independence at 90 days, defined as a modified Rankin (mRS) score of ≤2. Secondary outcomes were successful recanalization (modified treatment in cerebral infarction score (mTICI) 2b/3), symptomatic intracerebral hemorrhage (sICH), and mortality at 90 days post-procedure. We looked at 13 studies with a total of 30,407 participants in four meta-analyses and 5951 participants in nine observational studies. In most studies, patients in the PC-LVO group were male and younger than the AC-LVO group. Higher baseline National Institutes of Health Stroke Scale (NIHSS) score, lower rates of IVT, longer onset-to-groin puncture time, lower likelihood of sICH, higher 90-day mortality rates, and higher futile recanalization rates were frequently observed in the PC-LVO group with a large discrepancy in the likelihood of functional independence at 90 days with majority studies showing comparable rates. Hence, in patients with acute ischemic stroke caused by the PC-LVO, successful reperfusion can be achieved via MT, though at the cost of higher mortality rates. Such futile recanalization can be avoided with the refinement of procedures through technical improvements, skills training, and recognition of reliable predictors associated with it, which might help increase the efficacy of MT in PC-LVO. Additionally, future large-scale RCTs comparing patient selection and interventional strategies to avoid futile interventions are also needed.

Exclusively Posterior Circulation Stroke Caused by Internal Carotid Artery Thrombosis

A fetal posterior cerebral artery (FPCA) is an anatomic variant in which the posterior cerebral artery (PCA) is an embryological derivative of the internal carotid artery (ICA). Patients with FPCA may experience posterior circulation stroke (PCS) after a thrombotic event in the ICA system, while exclusively PCS caused by thrombosis of the ICA has rarely been reported. We report a patient with FPCA and summarize 3 types of exclusively PCS caused by FPCA due to thrombotic events in the ICA system. Type A: the thrombus involves the opening of the FPCA and obstructs the blood flow of the entire ICA. The contralateral ICA compensates the ipsilateral middle cerebral artery (MCA) and anterior cerebral artery (ACA) through the anterior communicating artery (ACOM). Type B: the thrombus involves the opening of the FPCA but does not block the blood flow of the entire ICA, which still perfuses the ipsilateral ACA and MCA. Type C: the thrombus only involves the FPCA and not the ipsilateral ICA. Patients with types A and B may obtain a good prognosis through endovascular treatment (EVT), while the benefits of this procedure in type C patients are unclear.

Single-center experience of endovascular treatment for patients with progressive posterior circulation cerebral infarction exceeding 24 h

Background

Evidence of endovascular treatment (ET) for patients with progressive infarction of the posterior circulation exceeding 24 h is lacking.

Objective

To evaluate the efficacy and safety of ET for progressive posterior circulation cerebral infarction.

Methods

This retrospective study evaluated the ET for 18 patients with posterior circulation infarction caused by vertebrobasilar artery occlusion from July 2017 to November 2018. The conditions of patients worsened despite receiving intravenous thrombolysis or combination therapy with clopidogrel and aspirin. The time from the onset of cerebral infarction to puncture was >24 h. The preoperative National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), and related risk factors of patients at 3 months were analyzed postoperatively.

Results

The preoperative NIHSS score was 10.6 (IQR: 6.5), and the time from onset to puncture was 163.5 ± 144.7 h. Postoperative blood flow was modified thrombolysis in cerebral infarction (mTICI) grade 2b or above. During the follow-up period, 1 patient died of basilar artery re-occlusion and pulmonary infection, and 1 died of postoperative hyperperfusion hemorrhage, with a mortality rate of 11.1% (2/18). No recurrent ischemic events were observed in any of the 16 patients during the 3-month follow-up period. The mean mRS score was 1.3 (IQR: 2.3), and 75% patients (12/16) had an mRS score of 0-2. There were no significant differences in age, gender, clinical characteristics, and stroke subtype between patients with mRS scores ≤2 and >2.

Conclusion

In patients with progressive posterior circulation cerebral infarction caused by vertebral basilar artery occlusion, ET is effective and safe even if the time from onset to puncture exceeds 24 h.

Outcome predictors in anterior and posterior ischemic strokes: a study based on the Iranian SITS registry

Ischemic stroke is the major form of stroke with two separate vascular territories. Many risk factors are related to stroke outcomes in both territories. The present descriptive research was carried out on the basis of data obtained from the Safe Implementation of Treatments in Stroke (SITS) registry on Iranian intravenous thrombolysis ischemic stroke cases. Vascular territory involved in each case and three-month excellent outcome, functional independence, mortality rate, and brain hemorrhage occurrence were determined. Univariable and multivariable logistics regression analyses were utilized in order to investigate association of ischemic stroke outcomes with the vascular territory involved and other related factors. Among 1566 patients 95.4% was anterior circulation stroke patients and 4.6% was posterior circulation stroke cases. There is no significant association between vascular territory with mortality (OR of PCS vs ACS: 0.74, 95% CI 0.37-1.46), excellent functional outcome (OR 0.72, 95% CI 0.44-1.19), functional outcome (OR 0.86, 95% CI 0.52-1.42) and local hemorrhage (OR 0.98, 95% CI 0.30-3.21). Among major risk factors, age, diabetes, NIHSS score and admission duration, increased significantly odds of three-month mortality, excellent outcome, and functional independence in the multivariate analysis. The highest of odds was in NIHSS score with a dose-response association. The vascular territory was not an outcome predictor in ischemic strokes. The most important predictor was baseline NIHSS.

Automatic detection and vascular territory classification of hyperacute staged ischemic stroke on diffusion weighted image using convolutional neural networks

Automated ischemic stroke detection and classification according to its vascular territory is an essential step in stroke image evaluation, especially at hyperacute stage where mechanical thrombectomy may improve patients' outcome. This study aimed to evaluate the performance of various convolutional neural network (CNN) models on hyperacute staged diffusion-weighted images (DWI) for detection of ischemic stroke and classification into anterior circulation infarct (ACI), posterior circulation infarct (PCI) and normal image slices. In this retrospective study, 253 cases of hyperacute staged DWI were identified, downloaded and reviewed. After exclusion, DWI from 127 cases were used and we created a dataset containing total of 2119 image slices, and separates it into three groups, namely ACI (618 slices), PCI (149 slices) and normal (1352 slices). Two transfer learning based CNN models, namely Inception-v3, EfficientNet-b0 and one self-derived modified LeNet model were used. The performance of the models was evaluated and activation maps using gradient-weighted class activation mapping (Grad-Cam) technique were made. Inception-v3 had the best overall accuracy (86.3%), weighted F1 score (86.2%) and kappa score (0.715), followed by the modified LeNet (85.2% accuracy, 84.7% weighted F1 score and 0.693 kappa score). The EfficientNet-b0 had the poorest performance of 83.6% accuracy, 83% weighted F1 score and 0.662 kappa score. The activation map showed that one possible explanation for misclassification is due to susceptibility artifact. A sufficiently high performance can be achieved by using CNN model to detect ischemic stroke on hyperacute staged DWI and classify it according to vascular territory.

Predictive value of serum initial brain natriuretic peptide and troponin on functional prognosis in noncardiogenic patients with anterior and posterior circulation cerebral infarction

BACKGROUND

Brain natriuretic peptide (BNP) and troponin have a close relationship with cardiogenic cerebral embolism (CCE), but their relationship with noncardiogenic patients with anterior circulation ischemia (ACI) and posterior circulation ischemia (PCI) is not clear.

OBJECTIVE

To explore the predictive value of serum initial BNP and troponin on the functional prognosis of patients with noncardiogenic ACI and PCI.

METHODS

Consecutive patients with first-episode cerebral infarction within 12 hours of symptom onset were enrolled in the present 1-year prospective cohort study. Serum levels of BNP and troponin were collected within 12 hours of onset. Infarction location was classified as ACI and PCI by magnetic resonance imaging (MRI). According to the modified Rankin Scale (mRS) score at 90 days after onset, ACI and PCI cases were respectively divided into a good prognosis group (mRS score between 0 and 2) and a poor prognosis group (mRS score between 3 and 6). The general state of health and results of laboratory examinations and other auxiliary examinations of all patients were recorded. Single-factor analysis and multivariate logistic regression analysis were used to assess the relationship between serum levels of BNP, troponin, and functional outcome.

RESULTS

The multivariate logistic regression found that higher levels of initial BNP (odds ratio [OR] = 1.024; 95% confidence interval [CI]: 1.006-1.041; p = 0.007) and C-reactive protein (CRP) (OR = 1.184; 95%CI: 1.024-1.369; p = 0.022) were independent predictors of poor functional prognosis of noncardiogenic PCI at 90 days after onset after adjusting for age, gender, ethnicity, history of hypertension and of diabetes.

CONCLUSIONS

The levels of initial BNP and CRP were related to poor functional outcomes in noncardiogenic PCI patients at 3 months, independent of troponin.

Long-Term Disability Outcomes for Patients With Ischemic Stroke Presenting With Visual Deficits

BACKGROUND

Ischemic strokes in both the anterior and posterior circulation can lead to visual deficits, which can affect functional ability. Thrombolytic therapies are often withheld to patients with visual deficits because of either being missed on initial evaluation or because of the misconception that their deficits are not as severe or as disabling. Alternatively, delays in patient arrival for emergent evaluation lead to missed opportunities for acute stroke treatment. This retrospective study aims to explore the differences in perceived long-term disability for patients with stroke who present with visual deficits vs those who do not as a manifestation of their acute stroke syndrome. In addition, we explore the differences in treatment effect with thrombolytics and further analyze if the region of ischemia causing the deficit leads to differences in disability outcomes.

METHODS

We conducted a retrospective analysis of patients with visual deficits as evidenced by an abnormal score on NIHSS categories related to vision (gaze palsy, visual fields, or extinction/inattention). Patients with Acute Ischemic Stroke were reviewed from the Houston Methodist Hospital Outcomes-based Prospective Endpoints in Stroke (HOPES) Registry from 2016-2021 for visual deficits. In total, 155 patient charts with visual deficits and 155 patient charts without a documented visual deficit were reviewed for ischemic stroke location (anterior vs posterior circulation), NIHSS scores, and thrombolytic therapies. The outcome variable was categorized using mRS, as mRS between 0 and 3 while mRS 4 to 6 was considered as poor functional outcome at 90 days. The independent variable was the vision group. A multivariable logistic regression model was constructed adjusting for demographics and comorbidities on the binary outcome.

RESULTS

Multivariable logistic model after adjusting for demographics and comorbidities showed that patients with acute ischemic stroke with vision defects were 4 times more likely to have poor functional outcomes at 90 days, with most of these patients (14% vs 6%; P < 0.05) suffering from severe disability compared with patients in the control group (i.e., patients with acute ischemic stroke without vision defects) (OR = 4.05; 95% CI [2.28-7.19]; P < 0.001). The application of thrombolytics and the location of ischemia (ACS vs PCS) did not result in a significant change in disability outcomes in patients with visual defects in this limited sample size.

CONCLUSIONS

The results of this study indicated that a large population of patients with ischemic stroke experience visual deficits and are, therefore, at an increased likelihood of worse functional outcome. This reveals the necessity for rehabilitation techniques that specifically target visual deficits to speed up the recovery process of these patients. Further studies with larger sample size are needed to assess whether the location of ischemic event and the application of thrombolytic treatments plays a role in the disability outcomes of these patients.

Timing of symptomatic intracranial hemorrhage after endovascular stroke treatment

INTRODUCTION

Little is known about the timing of occurrence of symptomatic intracranial hemorrhage (sICH) after endovascular therapy (EVT) for acute ischemic stroke. A better understanding could optimize in-hospital surveillance time points and duration. The aim of this study was to delineate the probability of sICH over time and to identify factors associated with its timing.

PATIENTS AND METHODS

We retrospectively analyzed data from the Dutch MR CLEAN trial and MR CLEAN Registry. We included adult patients who underwent EVT for an anterior circulation large vessel occlusion within 6.5 h of stroke onset. In patients with sICH (defined as ICH causing an increase of ⩾4 points on the National Institutes of Health Stroke Scale [NIHSS]), univariable and multivariable linear regression analysis was used to identify factors associated with the timing of sICH. This was defined as the time between end of EVT and the time of first CT-scan on which ICH was seen as a proxy.

RESULTS

SICH occurred in 205 (6%) of 3391 included patients. Median time from end of EVT procedure to sICH detection on NCCT was 9.0 [IQR 2.9-22.5] hours, with a rapidly decreasing incidence after 24 h. None of the analyzed factors, including baseline NIHSS, intravenous alteplase treatment, and poor reperfusion at the end of the procedure were associated with the timing of sICH.

CONCLUSION

SICHs primarily occur in the first hours after EVT, and less frequently beyond 24 h. Guidelines that recommend to perform frequent neurological assessments for at least 24 h after intravenous alteplase treatment can be applied to ischemic stroke patients treated with EVT.

Risk factors, infarct patterns and outcome differ between anterior and posterior circulation strokes attributed to intracranial large artery atherosclerotic steno-occlusive disease

BACKGROUND

Intracranial large artery atherosclerotic steno-occlusive disease (ICLAS) is the leading cause of acute ischemic stroke (AIS). The differences between anterior circulation stroke (ACS) and posterior circulation stroke (PCS) based on the TOAST classification have been well studied. However, data on the differences between ACS and PCS related to ICLAS are scarce, particularly from Saudi Arabia (SA). This study aimed to investigate the differences in demographics and clinico-radiological characteristics between patients with ACS and PCS attributed to ICLAS.

METHODS

This retrospective study included data for patients with ICLAS-related AIS grouped into two phenotypes as ACS and PCS. Demographics and clinico-radiological characteristics were compared between defined phenotypes using the chi-square test. The difference in the distribution of risk factors and radiological variables was ascertained by estimating the odds ratios (ORs) and 95 % confidence intervals (CI).

RESULTS

Data pertaining to 147 patients were included. Anterior circulation was involved in 66 % of patients. Territorial infarct pattern (68.7 %) was the most prevalent infarct pattern and artery to artery embolization (49 %) was the most prevalent mechanism for AIS. Watershed infarct pattern due to hemodynamic impairment was more prevalent in ACS than PCS (P = 0.0011). Diabetes mellitus (P = 0.02) and perforator infarct pattern (P = 0.001) were more prevalent in PCS than ACS. Baseline NIHSS, stroke severity and discharge status were statistically different between two phenotypes. Patients with infarction in posterior circulation have better functional outcome than those having in anterior circulation.

CONCLUSION

AIS attributed to ICLAS differs between ACS and PCS. Observed differences in risk factors' distribution, infarct pattern, underlying mechanism and outcome between two phenotypes carry important therapeutic and prognostic implications.

Neuroanatomical regions associated with non-progressive dysarthria post-stroke: a systematic review

Background

Dysarthria is a common and persisting sequela to stroke. It can have a negative influence on psychological wellbeing, and quality of life. This systematic review aimed to describe and identify the neuroanatomical regions associated with non-progressive dysarthria following stroke.

Methods

A systematic search of PubMed, Ovid Medline, CINAHL, Cochrane, Scopus, and ScienceDirect was conducted to identify all relevant articles published in peer-reviewed journals up to December 2021. Following data extraction, the National Institutes of Health (NIH) quality assessment tools were used to evaluate the methodological quality of the included studies.

Results

Out of 2186 papers found in the literature related to dysarthria post-stroke, 24 met the inclusion criteria. Eligible articles assessed 1150 post-stroke subjects. Out of them, 420 subjects had dysarthria from isolated lesions. Regarding dysarthric subjects with ischemic strokes, 153 sustained supratentorial infarctions, while 267 had infratentorial infarctions. The majority had pontine infarctions (n = 142), followed by infarctions in the corona radiata (n = 104), and the cerebellum (n = 64).

Conclusion

This systematic review is the first step toward establishing a neuroanatomical model of dysarthria throughout the whole brain. Our findings have many implications for clinical practice and provide a framework for implementing guidelines for early detection and management of dysarthria post-stroke.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02877-x.

Cognitive screen and employment long-term after infratentorial stroke

OBJECTIVES

Motor problems are well-described neurological deficits that occur commonly after an infratentorial ischemic stroke. However, the brain stem and cerebellum are also part of the neural interconnections responsible for cognition, emotions, and behavioral responses. We lack studies on long-term cognitive outcomes and patient employment after an infratentorial stroke. In the present study, we described and compared long-term poststroke cognitive outcomes and employment between patients that experienced infratentorial and supratentorial ischemic strokes.

MATERIALS AND METHODS

We included consecutive patients that experienced an acute ischemic stroke at ≤58 years of age. Patients were classified according to the stroke location. At seven years poststroke, surviving participants were assessed for neurological deficits (National Institutes of Health Stroke Scale [NIHSS]), functional outcome (modified Rankin Scale [mRS]), cognitive function Barrow Neurological Institute Screen (BNIS), and employment.

RESULTS

Among 141 participants, 25 (18%) had infratentorial and 116 (82%) had supratentorial strokes. At the 7-year poststroke follow-up, there was no significant difference in BNIS total scores; with a median of 43 (IQR 40.5-46) and 41 (IQR 38-46) in the infratentorial and supratentorial groups, respectively. This result indicated that cognitive dysfunction occurred frequently in both groups. Similar employment rates were observed in the infratentorial (48%) and supratentorial (55%) groups. Both groups had a median NIHSS score of 0 and a median mRS score of 2 at the 7-year follow-up.

CONCLUSION

Patients who survived an infratentorial or supratentorial ischemic stroke had similar rates of long-term cognitive dysfunction and difficulties in returning and/or remaining at work.

The Safety and Efficacy of Endovascular Treatment in Acute Ischemic Stroke Patients Caused by Large-Vessel Occlusion with Different Etiologies of Stroke: Data from ANGEL-ACT Registry

This study aimed to investigate the safety and efficacy of endovascular treatment (EVT) in acute ischemic stroke (AIS) patients caused by large-vessel occlusion (LVO) with different etiologies of stroke. A total of 928 AIS patients were assigned into intracranial atherosclerotic stenosis (ICAS)-LVO, cardioembolic (CE)-LVO, and artery to artery embolism (ATA)-LVO groups. The safety and efficacy endpoints were symptomatic intracranial hemorrhage (SICH) at 24 h after EVT, 90-day favorable outcomes (modified Rankin Scale (mRS) of 0-2), successful recanalization (modified thrombolysis in cerebral infarct (mTICI) 2b/3), and complete recanalization (mTICI 3). The logistic regression analysis was used to determine the associations between the safety and efficacy endpoints. There were 305 (32.9%), 535 (57.6%), and 88 (9.5%) patients in ICAS-LVO, CE-LVO, and ATA-LVO groups, respectively. No significant difference was found in the 90-day mRS and successful recanalization among the three groups. However, compared with the ICAS-LVO group, complete recanalization rate was higher in the CE-LVO (adjusted odds ratio, 4.50; 95% confidence interval (CI), 2.37-8.56) and ATA-LVO groups (aOR, 2.43; 95% CI, 1.16-5.10). The results of subgroup analysis showed a significant association between CE-LVO stroke etiology and complete recanalization in the age population < 65 years old (aOR, 14.33; 95% CI, 4.39-46.79, P = 0.019). Functional outcomes were similar among different etiologies of stroke. CE-LVO and ATA-LVO could be related to a higher rate of complete recanalization, and there was a trend of the increased risk of parenchymal hemorrhage in the CE-LVO group.

Prevalence and Risk Factors Comparison of Anterior and Posterior Intracranial Arterial Stenosis

The prevalence and risk factors of intracranial atherosclerotic stenosis (ICAS) located in the anterior circulation (AC) and posterior circulation (PC) has been scarcely noted in the general population. We aimed to determine ICAS prevalence and risk factor profile of AC and PC in a representative population. Data were from the China Hypertension Survey of Beijing. In total, 4800 people aged 35 years or older were enrolled in this subsurvey for ICAS, and 3954 participants were eligible for analysis. ICAS was assessed by transcranial Doppler. The prevalence of ICAS in AC was much greater than that in PC (11.9% vs. 4.2%), and subjects with ICAS in PC were 3.9 years older than those with ICAS in AC. Multivariable logistics regression showed that the odds of hypertension and diabetes increased by 79% (OR: 1.79, 95% CI: 1.40-2.27) and 35% (OR: 1.35, 95% CI: 1.04-1.75) in those with AC vascular lesions and by 3.35 times (OR: 3.35, 95% CI: 2.49-4.50) and 71% (OR: 1.71, 95% CI: 1.19-2.46) in those with PC vascular lesions compared with those without vascular lesions. Most modifiable vascular risk factors for ICAS appeared to exert similar magnitudes of risk for PC to AC lesions.

Stimulating the Facial Nerve to Treat Ischemic Stroke: A Systematic Review

Acute ischemic stroke (AIS) is a common devastating disease that has increased yearly in absolute number of cases since 1990. While mechanical thrombectomy and tissue plasminogen activator (tPA) have proven to be effective treatments, their window-of-efficacy time is very short, leaving many patients with no viable treatment option. Over recent years there has been a growing interest in stimulating the facial nerves or ganglions to treat AIS. Pre-clinical studies have consistently demonstrated an increase in collateral blood flow (CBF) following ganglion stimulation, with positive indications in infarct size and neurological scores. Extensive human trials have focused on trans-oral electrical stimulation of the sphenopalatine ganglion, but have suffered from operational limitations and non-significant clinical findings. Regardless, the potential of ganglion stimulation to treat AIS or elongate the window-of-efficacy for current stroke treatments remains extremely promising. This review aims to summarize results from recent trial publications, highlight current innovations, and discuss future directions for the field. Importantly, this review comes after the release of four important clinical trials that were published in mid 2019.

Patterns of ischemic posterior circulation strokes: A clinical, anatomical, and radiological review

Background

Posterior circulation and anterior circulation strokes share many clinical, pathogenetic and radiological features, although some clinical signs are highly specific to posterior circulation strokes. Arterial stenosis and occlusions occur in significant numbers in both acute posterior circulation and anterior circulation strokes, making them good candidates for endovascular treatment. Among posterior circulation strokes, basilar artery occlusions stand out because of the diagnostic and acute treatment challenges.

Methods

We reviewed the literature on clinical stroke syndromes and neuroimaging findings and systematically describe for each anatomical site of stroke the detailed clinical and radiological information (anatomical representation, diffusion weighted imaging and angiographic sequences). The principles of neuroimaging of posterior circulation strokes and the prognosis for each stroke localization are also discussed.

Review summary

Stroke syndromes in the territories of the vertebral, basilar, cerebellar, and posterior cerebral arteries are presented. Features typical of posterior circulation strokes are highlighted, including patterns of basilar artery occlusions. Clinical severity and prognosis of posterior circulation strokes are highly variable, and given that they are more difficult to detect on CT-based neuroimaging, magnetic resonance imaging is the technique of choice in suspected posterior circulation strokes. Rapid identification of arterial occlusion patterns may provide prognostic information and support acute revascularization decisions.

Conclusions

Posterior circulation stroke syndromes tightly reflect lesion localization and arterial occlusion patterns. Although many clinical and pathogenetic features are similar to anterior circulation strokes, notable differences exist in terms of clinical presentation, stroke mechanism, prognosis, and response to acute recanalization.

IV-Thrombolysis in Ischemic Stroke With Unknown Time of Onset-Safety and Outcomes in Posterior vs. Anterior Circulation Stroke

Background: rt-PA for ischemic stroke in the unknown or extended time window beyond the first 4. 5 h after symptom onset is safe and effective for certain patients after selection by multimodal neuroimaging. However, the evidence for this approach comes mainly from patients with anterior circulation stroke (ACS), while the data on posterior circulation stroke (PCS) are scarce.

Methods: Ischemic stroke patients treated with IV-thrombolysis in the unknown or extended time window between January 2011 and May 2019 were identified from an institutional registry. The patients were categorized into PCS or ACS based on clinico-radiological findings. We analyzed the hemorrhagic complications, clinical and imaging efficacy outcomes, and mortality rates by comparing the PCS and ACS patient groups. Adjusted outcome analyses were performed after propensity score matching for the relevant factors.

Results: Of the 182 patients included, 38 (20.9%) had PCS and 144 (79.1%) had ACS. Symptomatic acute large vessel occlusion (LVO) was present in 123 patients on admission [27 (22.0%) PCS and 96 (78.0%) ACS]. The score on the National Institutes of Health Stroke Scale (NIHSS), the time from last seen normal, and the door-to-needle times were similar in PCS and ACS. In patients with LVO, the NIHSS score was lower [8 (5–15) vs. 14 (9–18), p = 0.005], and infarction visible on follow-up imaging was less common [70.4 vs. 87.5%; aRD, −18.9% (−39.8 to −2.2%)] in the PCS patient group. There was a trend toward a lower risk for intracranial hemorrhage (ICH) following intravenous thrombolysis in PCS vs. ACS, without reaching a statistical significance [5.3 vs. 16.9%; aRD, −10.4% (−20.4 to 4.0%)]. The incidence of symptomatic ICH [according to the ECASS III criteria: 2.6 vs. 3.5%; aRD, −2.9% (−10.3 to 9.2%)], efficacy outcomes, and mortality rates were similar in PCS and ACS patients.

Conclusions: In this real-world clinical cohort, the safety and the efficacy of rt-PA for ischemic stroke in the unknown or extended time window did not show relevant differences between PCS and ACS, with a trend toward less hemorrhagic complications in PCS. The findings reconfirm the clinician in the usage of rt-PA beyond the first 4.5 h also in selected patients with PCS.

Pitfalls in the Diagnosis of Posterior Circulation Stroke in the Emergency Setting

Posterior circulation stroke (PCS), caused by infarction within the vertebrobasilar arterial system, is a potentially life-threatening condition and accounts for about 20–25% of all ischemic strokes. Diagnosing PCS can be challenging due to the vast area of brain tissue supplied by the posterior circulation and, as a consequence, the wide range of—frequently non-specific—symptoms. Commonly used prehospital stroke scales and triage systems do not adequately represent signs and symptoms of PCS, which may also escape detection by cerebral imaging. All these factors may contribute to causing delay in recognition and diagnosis of PCS in the emergency context. This narrative review approaches the issue of diagnostic error in PCS from different perspectives, including anatomical and demographic considerations as well as pitfalls and problems associated with various stages of prehospital and emergency department assessment. Strategies and approaches to improve speed and accuracy of recognition and early management of PCS are outlined.

Predictors for affected stroke territory and outcome of acute stroke treatments are different for posterior versus anterior circulation stroke

Distinct patient characteristics have been proposed for ischaemic stroke in the anterior versus posterior circulation. However, data on functional outcome according to stroke territory in patients with acute stroke treatment are conflicting and information on outcome predictors is scarce. In this retrospective study, we analysed functional outcome in 517 patients with stroke and thrombolysis and/or thrombectomy treated at the University Hospital Zurich. We compared clinical factors and performed multivariate logistic regression analyses investigating the effect of outcome predictors according to stroke territory. Of the 517 patients included, 80 (15.5%) suffered a posterior circulation stroke (PCS). PCS patients were less often female (32.5% vs. 45.5%, p = 0.031), received thrombectomy less often (28.7% vs. 48.3%, p = 0.001), and had lower median admission NIHSS scores (5 vs. 10, p < 0.001) as well as a better median three months functional outcome (mRS 1 vs. 2, p = 0.010). Predictors for functional outcome were admission NIHSS (OR 0.864, 95% CI 0.790–0.944, p = 0.001) in PCS and age (OR 0.952, 95% CI 0.935–0.970, p < 0.001), known symptom onset (OR 1.869, 95% CI 1.111–3.144, p = 0.018) and admission NIHSS (OR 0.840, 95% CI 0.806–0.876, p < 0.001) in ACS. Acutely treated PCS and ACS patients differed in their baseline and treatment characteristics. We identified specific functional outcome predictors of thrombolysis and/or thrombectomy success for each stroke territory.

Impact of revascularization therapies on outcome of posterior circulation ischemic stroke: The Indo-US stroke project

INTRODUCTION

Posterior circulation strokes (PCS) have been less extensively studied than anterior circulation strokes (ACS), especially regarding revascularization therapies. We analyzed the differences in baseline stroke characteristics, revascularization therapy and 3-month outcomes between PCS and ACS in a large prospective multicentre Indian stroke registry.

METHODS

Patients with acute ischemic stroke recruited in the Indo-US collaborative stroke project from January 2012 to August 2014 were classified into PCS and ACS based on imaging-confirmed infarct location. Demographics, stroke severity, risk factors, and mechanisms were compared. We further compared these parameters in the subgroups who received revascularization therapies (RT) and no revascularization therapies (NRT). The primary outcome was 3-month modified Rankin scale (mRS).

RESULTS

Of 1889 patients (1270 males), 1478 (78.2%) had ACS and 411 (21.8%) PCS. The median NIHSS was lower in PCS (7 vs 11, p < 0.001). Diabetes mellitus and hypertension were more common in PCS and rheumatic heart disease in ACS. Small artery occlusion was higher in PCS (23.8% vs 12.9%, p < 0.001). Only 28 (6.8%) PCS received RT compared to 213 (14.4%) ACS. At 90 days, a good functional outcome (mRS 0-2) was more common in PCS (56.4% vs 45.9%, p < 0.001) in NRT group, while no significant difference was noted in RT group. Stroke territory was not an independent predictor of 3-month outcome in regression analysis. In-hospital mortality was not different between the groups.

CONCLUSIONS

The 3-month functional outcome and in-hospital mortality were not different between ACS and PCS. Compared to ACS, PCS received revascularization therapies less often.

Transcranial Doppler Combined With Quantitative Electroencephalography Brain Function Monitoring for Estimating the Prognosis of Patients With Posterior Circulation Cerebral Infarction

Posterior circulation cerebral infarction (PCCI) can lead to deceased infratentorial cerebral blood flow (CBF) and metabolism. Neural activity is closely related to regional cerebral blood flow both spatially and temporally. Transcranial Doppler (TCD) combined with quantitative electroencephalography (QEEG) is a technique that evaluates neurovascular coupling and involves synergy between the metabolic and vascular systems. This study aimed to monitor brain function using TCD-QEEG and estimate the efficacy of TCD-QEEG for predicting the prognosis of patients with PCCI. We used a TCD-QEEG recording system to perform quantitative brain function monitoring; we recorded the related clinical variables simultaneously. The data were analyzed using a Cox proportional hazards regression model. Receiver-operating characteristic (ROC) curve analysis was used to evaluate the cut-off for the diastolic flow velocity (VD) and (delta + theta)/(alpha + beta) ratio (DTABR). The area under the ROC curve (AUROC) was calculated to assess the predictive validity of the study variables. Forty patients (aged 63.7 ± 9.9 years; 30 men) were assessed. Mortality at 90 days was 40%. The TCD indicators of VD [hazard ratio (HR) 0.168, confidence interval (CI) 0.047-0.597, p = 0.006] and QEEG indicators of DTABR (HR 12.527, CI 1.637-95.846, p = 0.015) were the independent predictors of the clinical outcomes. The AUROC after combination of VD and DTABR was 0.896 and showed better predictive accuracy than the Glasgow Coma Scale score (0.75), VD (0.76), and DTABR (0.781; all p < 0.05). TCD-QEEG provides a good understanding of the coupling mechanisms in the brain and can improve our ability to predict the prognosis of patients with PCCI.

Treatment strategies for patients with concurrent blunt cerebrovascular and traumatic brain injury

Patients who present with traumatic brain injury (TBI) combined with blunt cerebrovascular injuries (BCVI) are difficult to manage, in part because treatment for each entity may exacerbate the other. It is necessary to develop a treatment paradigm that ensures maximum benefit while mitigating the opposing risks. A cohort of 150 patients from 2015 to present, with either internal carotid artery (ICA) and/or vertebral artery (VA) dissections or pseudoaneurysms, was cross-referenced with those who had sustained TBI. Of the 38 patients identified with both TBI and BCVI, 25 suffered ICA injuries, 10 had VA injuries and 3 had combined ICA/VA injuries. Unilateral BCVI occurred in 30 patients, while 8 had bilateral BCVI. Two patients required surgical intervention for TBI, and 5 patients required endovascular intervention for BCVI. Positive emboli detection studies (EDS) on transcranial dopplers (TCD) were demonstrated in 19 patients, with 9 patients having radiographic evidence of stroke. Anti-platelet therapy was initiated in 32 patients, and anti-coagulation in 10 patients, without new or worsening intracranial hemorrhages (ICH). Overall, 76% of patients were able to be discharged home or to rehabilitation, with good recovery demonstrated in 73% of the patients who had appropriate follow-up. In the setting of concurrent TBI and BCVI, use of anti-platelet/coagulation to prevent stroke can be safe if monitored closely. Here we describe a treatment paradigm which weighs the risk and benefits of therapies based on severity of ICH and stroke prevention, which tended to result in good disposition and recovery.

Acute Management Should Be Optimized in Patients with Less Specific Stroke Symptoms: Findings from a Retrospective Observational Study

Anterior circulation stroke (ACS) is associated with typical symptoms, while posterior circulation stroke (PCS) may cause a wide spectrum of less specific symptoms. We aim to assess the correlation between the initial presentation of acute ischemic stroke (AIS) symptoms and the treatment timeline. Using a retrospective, observational, single-center study, the set consists of 809 AIS patients treated with intravenous thrombolysis (IVT) and/or endovascular treatment (EVT). We investigate the impact of baseline clinical AIS symptoms and the affected vascular territory on recanalization times in patients treated with IVT only and EVT (±IVT). Regarding the IVT-only group, increasing the National Institutes of Health Stroke Scale (NIHSS) score on admission and speech difficulties are associated with shorter (by 1.59 ± 0.76 min per every one-point increase; p = 0.036, and by 24.56 ± 8.42 min; p = 0.004, respectively) and nausea/vomiting with longer (by 43.72 ± 13.13 min; p = 0.001) onset-to-needle times, and vertigo with longer (by 8.58 ± 3.84 min; p = 0.026) door-to-needle times (DNT). Regarding the EVT (±IVT) group, coma is associated with longer (by 22.68 ± 6.05 min; p = 0.0002) DNT, anterior circulation stroke with shorter (by 47.32 ± 16.89 min; p = 0.005) onset-to-groin time, and drooping of the mouth corner with shorter (by 20.79 ± 6.02 min; p = 0.0006) door-to-groin time. Our results demonstrate that treatment is initiated later in strokes with less specific symptoms than in strokes with typical symptoms.

Thrombectomy for Posterior Circulation Stroke: Predictors of Outcomes in a Brazilian Registry

BACKGROUND

Acute basilar artery occlusion is a devastating life-threatening condition. Early recanalization is the therapeutic goal in patients with acute ischemic stroke. Despite the high rates of recanalization achieved with modern devices for basilar occlusions, many patients have had poor clinical outcomes. This study aimed to assess the predictors of good and poor outcomes among patients with basilar artery occlusion treated with thrombectomy.

METHODS

A consecutive registry of 80 patients was included in this retrospective study. The primary end point was to access variables associated with neurologic outcomes defined by a modified Rankin Scale (mRS) score of 0-2, symptomatic intracranial hemorrhage (sICH), and mortality at 3 months follow-up.

RESULTS

Recanalization was achieved in 86.2%, and the sICH rate was 8.7%. A good neurologic outcome (mRS score 0-2) was observed in 26.2% and a moderate outcome (mRS score 0-3) in 32.5% of patients. The mortality was 38.7% at 3 months follow-up.

CONCLUSIONS

After thrombectomy for posterior circulation strokes, young patients, V4-proximal basilar occlusion, (high) baseline posterior circulation Alberta Stroke Program Early CT Score, and complete recanalization were independent predictors of good neurologic outcomes. Failure to recanalize was strongly related to sICH and mortality. In addition, diabetes, atrial fibrillation, and baseline National Institutes of Health Stroke Scale scores ≥10 had an independent association with mortality. This study contributes to the knowledge required to optimize recanalization treatments for posterior circulation strokes and may help to improve future clinical studies.

Recent silent infarcts do not increase the risk of haemorrhage after intravenous thrombolysis

BACKGROUND AND PURPOSE

Haemorrhagic transformation (HT) is one of the main risks of intravenous thrombolysis (IVT) for acute ischaemic stroke. Contraindications serve to exclude patients at high risk of HT after IVT. One of these contraindications is a stroke within the preceding 3 months. It is unclear if this contraindication should include recent clinically silent infarcts (RSIs). The aim of this study was to investigate whether RSIs are associated with a higher risk of HT and a worse clinical outcome after IVT for acute ischaemic stroke.

METHODS

In a retrospective monocentric cohort study, all patients who received IVT for acute ischaemic stroke based on magnetic resonance imaging were assessed over 5 years. RSIs were defined as lesions with diffusion restriction and positive signal on fluid attenuated inversion recovery sequences. Patients with RSIs (RSI+) were compared to patients without RSIs (RSI-) regarding HT after IVT and clinical outcome.

RESULTS

In all, 981 patients who had received IVT for acute ischaemic stroke demonstrated by magnetic resonance imaging were identified. RSIs were detected in 115 patients (11.5%). HT after IVT was observed in 32 (28.3%) RSI+ and 56 (25.8%) RSI- patients (P = 0.624). Symptomatic intracerebral haemorrhage was noted in two (1.8%) RSI+ and five (2.3%) RSI- patients (P = 1.000). No differences in clinical outcome were observed.

CONCLUSIONS

The detection of RSIs in patients treated with IVT for acute ischaemic stroke was not associated with a higher risk of HT or a worse clinical outcome. The results of this study argue against considering RSIs as a contraindication for IVT.

Timing of initiation of oral anticoagulants in patients with acute ischemic stroke and atrial fibrillation comparing posterior and anterior circulation strokes

Introduction

The aim of this study in patients with acute posterior ischaemic stroke (PS) and atrial fibrillation (AF) was to evaluate (1) the risks of recurrent ischaemic event and severe bleeding and (2) these risks in relation with oral anticoagulant therapy (OAT) and its timing.

Materials and Methods

Patients with PS were prospectively included; the outcome events of these patients were compared with those of patients with anterior stroke (AS) which were taken from previous registries. The primary outcome was the composite of stroke recurrence, transient ischaemic attack, symptomatic systemic embolism, symptomatic cerebral bleeding and major extracranial bleeding occurring within 90 days from acute stroke.

Results

A total of 2470 patients were available for the analysis: 473 (19.1%) with PS and 1997 (80.9%) with AS. Over 90 days, 213 (8.6%) primary outcome events were recorded: 175 (8.7%) in patients with AS and 38 (8.0%) in those with PS. In patients who initiated OAT within 2 days, the primary outcome occurred in 5 out of 95 patients (5.3%) with PS compared to 21 out of 373 patients (4.3%) with AS (OR 1.07; 95% CI 0.39-2.94). In patients who initiated OAT between days 3 and 7, the primary outcome occurred in 3 out of 103 patients (2.9%) with PS compared to 26 out of 490 patients (5.3%) with AS (OR 0.54; 95% CI 0.16-1.80).

Discussion

our findings suggest that, when deciding the time to initiate oral anticoagulation, the location of stroke, either anterior or posterior, does not predict the risk of outcome events.

Conclusions

Patients with PS or AS and AF appear to have similar risks of ischaemic or haemorrhagic events at 90 days with no difference concerning the timing of initiation of OAT.

Detection of Migrainous Infarction with Formal Visual Field Testing: A Case Report

Introduction

Cerebrovascular accidents (CVA) of the posterior circulation are a rare complication of migraine, and present with atypical CVA symptomatology.

Case Report

A 49-year-old-male presented with complaint of persistent visual aura and resolved mild cephalgia. His exam corroborated his reported incomplete left inferior quadrantanopia, and was confirmed by immediate formal optometry evaluation. Occipital CVA was confirmed on admission.

Conclusion

Migrainous strokes of posterior circulation should be considered as a potential diagnosis in any headache patient with persistent visual aura. This case suggests that incorporation of formal visual field testing in the emergent setting can shorten the time required for diagnosis in certain circumstances.

Detailed phenotyping of posterior vs. anterior circulation ischemic stroke: a multi-center MRI study

OBJECTIVE

Posterior circulation ischemic stroke (PCiS) constitutes 20-30% of ischemic stroke cases. Detailed information about differences between PCiS and anterior circulation ischemic stroke (ACiS) remains scarce. Such information might guide clinical decision making and prevention strategies. We studied risk factors and ischemic stroke subtypes in PCiS vs. ACiS and lesion location on magnetic resonance imaging (MRI) in PCiS.

METHODS

Out of 3,301 MRIs from 12 sites in the National Institute of Neurological Disorders and Stroke (NINDS) Stroke Genetics Network (SiGN), we included 2,381 cases with acute DWI lesions. The definition of ACiS or PCiS was based on lesion location. We compared the groups using Chi-squared and logistic regression.

RESULTS

PCiS occurred in 718 (30%) patients and ACiS in 1663 (70%). Diabetes and male sex were more common in PCiS vs. ACiS (diabetes 27% vs. 23%, p < 0.05; male sex 68% vs. 58%, p < 0.001). Both were independently associated with PCiS (diabetes, OR = 1.29; 95% CI 1.04-1.61; male sex, OR = 1.46; 95% CI 1.21-1.78). ACiS more commonly had large artery atherosclerosis (25% vs. 20%, p < 0.01) and cardioembolic mechanisms (17% vs. 11%, p < 0.001) compared to PCiS. Small artery occlusion was more common in PCiS vs. ACiS (20% vs. 14%, p < 0.001). Small artery occlusion accounted for 47% of solitary brainstem infarctions.

CONCLUSION

Ischemic stroke subtypes differ between the two phenotypes. Diabetes and male sex have a stronger association with PCiS than ACiS. Definitive MRI-based PCiS diagnosis aids etiological investigation and contributes additional insights into specific risk factors and mechanisms of injury in PCiS.

Posterior circulation ischaemic stroke-a review part I: anatomy, aetiology and clinical presentations

Posterior circulation ischaemia is a clinicopathological condition with complex symptomatology associated with an infarction within the vertebrobasilar arterial system. Posterior circulation strokes account for about 20-25% of all ischemic strokes and remain a significant cause of patient disability and mortality. Diagnosis can be challenging because presenting symptoms are often non-focal and because there is a substantial overlap in symptoms and signs of ischaemia in the anterior circulation. Despite better imaging techniques, diagnosis and treatment of life-threatening conditions, such as basilar artery occlusions, are often delayed. Therefore, early detection of symptoms and causes of posterior circulation ischaemia is essential for choosing the most appropriate therapy. In this review, we summarise the anatomy, aetiology, typical presentations and characteristic findings of common strokes resulting from disease in the vertebrobasilar arterial system.

Posterior circulation ischemic stroke-a review part II: imaging and acute treatment

Posterior circulation strokes affect the vertebrobasilar arterial system, account for about 20-25% of all ischemic strokes, and are a significant cause of patient disability and mortality. Diagnosis can be challenging; clinical presentation and common pitfalls facing posterior circulation stroke have been discussed elsewhere. In the first part of the review, we focus on the imaging, discussing the information that can be gathered through a correct selection and interpretation of different possible studies helping to achieve an early diagnosis and to select the best medical treatment. In the second part of the review, we will discuss the best therapeutic treatments available at the moment for posterior circulation ischemia.