Intracranial Calcification is Predictive for Hemorrhagic Transformation and Prognosis After Intravenous Thrombolysis in Non-Cardioembolic Stroke Patients

A weakly supervised deep learning model integrating noncontrasted computed tomography images and clinical factors facilitates haemorrhagic transformation prediction after intravenous thrombolysis in acute ischaemic stroke patients

BACKGROUND

Haemorrhage transformation (HT) is a serious complication of intravenous thrombolysis (IVT) in acute ischaemic stroke (AIS). Accurate and timely prediction of the risk of HT before IVT may change the treatment decision and improve clinical prognosis. We aimed to develop a deep learning method for predicting HT after IVT for AIS using noncontrast computed tomography (NCCT) images.

METHODS

We retrospectively collected data from 828 AIS patients undergoing recombinant tissue plasminogen activator (rt-PA) treatment within a 4.5-h time window (n = 665) or of undergoing urokinase treatment within a 6-h time window (n = 163) and divided them into the HT group (n = 69) and non-HT group (n = 759). HT was defined based on the criteria of the European Cooperative Acute Stroke Study-II trial. To address the problems of indiscernible features and imbalanced data, a weakly supervised deep learning (WSDL) model for HT prediction was constructed based on multiple instance learning and active learning using admission NCCT images and clinical information in addition to conventional deep learning models. Threefold cross-validation and transfer learning were performed to confirm the robustness of the network. Of note, the predictive value of the commonly used scales in clinics associated with NCCT images (i.e., the HAT and SEDAN score) was also analysed and compared to measure the feasibility of our proposed DL algorithms.

RESULTS

Compared to the conventional DL and ML models, the WSDL model had the highest AUC of 0.799 (95% CI 0.712-0.883). Significant differences were observed between the WSDL model and five ML models (P < 0.05). The prediction performance of the WSDL model outperforms the HAT and SEDAN scores at the optimal operating point (threshold = 1.5). Further subgroup analysis showed that the WSDL model performed better for symptomatic intracranial haemorrhage (AUC = 0.833, F1 score = 0.909).

CONCLUSIONS

Our WSDL model based on NCCT images had relatively good performance for predicting HT in AIS and may be suitable for assisting in clinical treatment decision-making.

Prediction factors and clinical significance of different types of hemorrhagic transformation after intravenous thrombolysis

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) after intravenous thrombolysis (IVT) in acute ischemic stroke seriously affects the prognosis of patients. This study aimed to investigate the risk factors of different types of HT and their correlation with prognosis after IVT.

METHODS

Based on the CASE II registry, we included patients with acute ischemic stroke who received IVT within 4.5 h of onset. HT was further divided into hemorrhagic infarction (HI) and parenchymal hemorrhage (PH). Poor outcome was defined as a modified Rankin Scale (mRS) score of 3-6 at 3 months. Multivariate logistic regression analysis was used to determine the independent influencing factors of HT subtypes and clinical outcome.

RESULTS

Among 13108 included patients, 541 (4.1%) developed HI and 440 (3.4%) developed PH. In multivariate analysis, age (OR 1.038, 95% CI 1.028 to 1.049, p < 0.001), atrial fibrillation (OR 1.446, 95% CI 1.141 to 1.943, p = 0.002), baseline diastolic pressure (OR 1.012, 95% CI 1.004 to 1.020, p = 0.005), baseline NIHSS score (OR 1.060, 95% CI 1.049 to 1.071, p < 0.001) and onset to treatment time (OR 1.002, 95% CI 1.000 to 1.004, p = 0.020) independently predicted PH after IVT. In the patients with HT, PH (OR 3.611, 95% CI 2.540 to 5.134, p < 0.001) and remote hemorrhage (OR 1.579, 95% CI 1.115 to 2.235, p = 0.010) were independently related to poor outcome.

CONCLUSIONS

Different types of HT after IVT had different risk factors and clinical significance. The occurrence of PH and remote hemorrhage independently increased the risk of poor outcome.

Hemorrhagic Transformation of Ischemic Strokes

Ischemic stroke, resulting from insufficient blood supply to the brain, is among the leading causes of death and disability worldwide. A potentially severe complication of the disease itself or its treatment aiming to restore optimal blood flow is hemorrhagic transformation (HT) increasing morbidity and mortality. Detailed summaries can be found in the literature on the pathophysiological background of hemorrhagic transformation, the potential clinical risk factors increasing its chance, and the different biomarkers expected to help in its prediction and clinical outcome. Clinicopathological studies also contribute to the improvement in our knowledge of hemorrhagic transformation. We summarized the clinical risk factors of the hemorrhagic transformation of ischemic strokes in terms of risk reduction and collected the most promising biomarkers in the field. Also, auxiliary treatment options in reperfusion therapies have been reviewed and collected. We highlighted that the optimal timing of revascularization treatment for carefully selected patients and the individualized management of underlying diseases and comorbidities are pivotal. Another important conclusion is that a more intense clinical follow-up including serial cranial CTs for selected patients can be recommended, as clinicopathological investigations have shown HT to be much more common than clinically suspected.

Dietary Flavonoid Intake and Carotid Calcification in Patients with Ischemic Stroke

INTRODUCTION

Owing to the antioxidant and anti-inflammatory effects, flavonoids can influence the initiation and development of atherosclerosis, but the underlying mechanisms remain largely undetermined. This study aimed to evaluate the associations between dietary flavonoids and carotid calcification in patients with ischemic stroke.

METHODS

This study screened consecutive patients with ischemic stroke via Nanjing Stroke Registry Program from February 2016 to April 2021. A semiquantitative food frequency questionnaire was used to evaluate dietary consumption of flavonoids and other nutritional components. Presence and degree of carotid calcification were determined according to Agatston scores on computer tomography angiography. Logistic regression was performed to evaluate the association between dietary flavonoids (total flavonoids, flavonols, flavones, flavanones, flavan-3-ols, anthocyanins, and isoflavones) and carotid calcification.

RESULTS

Of the 601 enrolled patients, 368 (61.2%) were detected with carotid calcification. Patients with high intake of total flavonoids (the fifth quintile) had a 52% lower carotid calcification risk than those with low intake (the first quintile; odds ratio [OR] = 0.48; 95% confidence interval [CI], 0.26-0.90; p = 0.007 for trends) after adjusting for major confounders. Patients with high intake of flavan-3-ols (the fifth quintile) had a 51% lower carotid calcification risk than those with low intake (the first quintile; OR = 0.49; 95% CI, 0.25-0.97; p = 0.016 for trends).

CONCLUSION

Dietary flavonoid intake is associated with carotid calcification, and, therefore, may influence the risk of stroke occurrence and recurrence.

Symptomatic Intracranial Hemorrhage after Ischemic Stroke Treated with Bridging Revascularization Therapy

(1) Background: bridging revascularization therapy is now the standard of care in patients with ischemic stroke due to large vessel occlusion. This study aimed to determine the frequency of symptomatic intracranial hemorrhage (sICH) related to this treatment, and to assess contributing factors and patients' outcomes. (2) Methods: consecutive ischemic stroke patients treated with bridging therapy were prospectively enrolled. sICH (intracranial hemorrhage with an increase in NIHSS score of ≥4 points) was assessed on imaging at 24 h. The functional status of patients was measured at 6 months using the mRS score; (3) Results: 176 patients were included (mean age 68.7 ± 1.2 years, 52.3% women), among whom 15 (8.5%) had sICH. Patients with sICH had more frequent alcohol abuse (30.1% versus 9.7%, p = 0.023), prestroke use of dual antiplatelet therapy (14.3% versus 1.3%, p = 0.002), higher NIHSS scores at admission (median score 20.5 versus 15, p = 0.01), greater systolic blood pressure upon admission, more frequent vascular intracranial calcifications (p = 0.004), leukoaraiosis (p = 0.001), and intracranial atheroma (p = 0.02), and higher neutrophil-to-lymphocyte ratios (p = 0.02) and neutrophil-to-platelet ratios (p = 0.04). At 6-month follow-up, 9 (60%) patients with sICH died, versus 18% of patients without sICH (p < 0.001). Only 1 (7%) patient with sICH had a good functional outcome, defined as an mRS score of 0 to 2, versus 51% of patients without sICH. (4) Conclusions: one in twelve ischemic stroke patients treated with bridging therapy suffered sICH. Given the observed poor outcomes after sICH, further studies are required to better identify patients at risk to help clinicians in guiding therapeutic strategies.

The correlation between intracranial arterial calcification and the outcome of reperfusion therapy

OBJECTIVE

Intracranial arterial calcification (IAC) is a risk factor of ischemic stroke. However, the relationship between IAC patterns and clinical outcome of ischemic stroke remains controversial. We aimed to investigate the correlation between IAC patterns and the effects of reperfusion therapy among acute stroke patients.

METHODS

Consecutive acute ischemic stroke patients who underwent reperfusion therapy were included. IAC was categorized as intimal or medial. Based on its involvement, IAC was further classified as diffuse or focal. Neurologic dysfunction was assessed by the National Institute of Health stroke scale (NIHSS). Clinical outcome including favorable neurologic outcome (FNO) and early neurologic deterioration (END) were assessed.

RESULTS

Of 130 patients, 117 had IAC. Intimal IAC was identified in 74.6% of patients and medial IAC was present in 64.6% of patients. Diffuse IAC was present in 31.5% of patients. All diffuse IACs were medial pattern. Diffuse IAC was associated with higher baseline NIHSS (p = 0.011) and less FNO (p = 0.047). Compared with patients with focal or single diffuse IAC, patients with multiple diffuse IAC had higher baseline NIHSS (p = 0.002) and less FNO (p = 0.024). Multivariable linear regression (p < 0.001) and logistic regression (p = 0.027) suggested that multiple diffuse IAC was associated with higher baseline NIHSS and less FNO. No significant association was found between END and different IAC patterns.

INTERPRETATION

Multiple diffuse medial IAC may predict severer neurologic dysfunction and less favorable neurologic outcome after reperfusion therapy in acute stroke patients.

Increased Serum EphrinA1 Is Associated with Parenchymal Hematoma after Ischemic Stroke

INTRODUCTION

Previous preclinical studies reported that the level of serum EphrinA1 was associated with blood-brain barrier disruption; however, its role in predicting parenchymal hematoma (PH) after ischemic stroke is underexplored. We aimed to explore the association between the level of serum EphrinA1 and PH in patients with ischemic stroke.

METHODS

Patients with ischemic stroke after onset from West China Hospital, Sichuan University, were prospectively enrolled between January 2017 and December 2019. The level of serum EphrinA1 at baseline was measured after admission. PH was diagnosed as hematoma within the infarct territory detected on the brain CT/MRI scans within 7 days after onset but not on the initial scan according to European Cooperative Acute Stroke Study (ECASS) III criteria. The association between the level of serum EphrinA1 and PH after ischemic stroke was assessed by multiple logistic regression analysis.

RESULTS

A total of 667 patients were included in the final analysis. The mean age was 67.20 ± 14.31 years, and 57.87% (368/667) were males. Of the 667 patients, 65 (9.75%) patients had PH. The median of EphrinA1 on admission was 82.83 ng/mL (IQR, 70.11-93.75 ng/mL). Compared with patients without PH, those with PH had a higher level of serum EphrinA1 (p = 0.024). Patients were divided into 3 categories based on EphrinA1 tertiles (T1, <79.11 ng/mL, n = 223; T2, 79.11-93.75 ng/mL, n = 222; and T3, >93.75 ng/mL, n = 222). After adjusting for age, sex, atrial fibrillation, smoking, statins, antiplatelets, Trail of Org 10172 in Acute Stroke Treatment (TOAST) classification and National Institutes of Health Stroke Scale (NIHSS) score ≥15, patients in the second and third EphrinA1 tertiles showed a significant increase in PH compared with those in the lowest tertile (OR 2.44, 95% CI: 1.10-5.40, p = 0.028; OR 2.61, 95% CI: 1.19-5.74, p = 0.017, respectively). Additionally, adjusting for reperfusion therapy (thrombolysis and/or endovascular therapy), only patients in the highest group (tertile 3) had a significantly higher risk of PH compared to the lowest group (OR 2.30, 95% CI: 1.03-5.13, p = 0.042).

CONCLUSION

Higher serum EphrinA1 is independently associated with a higher risk of PH after ischemic stroke. Future studies with larger sample sizes are needed to validate our findings and elucidate the potential role of EphrinA1 in PH.

ANALYSIS OF THE BLOOD HYPERCOAGULATION RISK IN PATIENTS WITH ISCHEMIC ATHEROTHROMBOTIC STROKE DEPENDING OF THE VDR GENE POLYMORPHISMS

OBJECTIVE

Aim: of our study was the analysis of the blood hypercoagulation risk in patients with ischemic atherotrombotic stroke depending of the VDR gene polymorphisms.

PATIENTS AND METHODS

Materials and Methods: Blood of 170 patients with ischemic atherothrombotic stroke (IATS) and 124 healthy individuals (control group) was used for genotyping. Four polymorphisms (FokI, BsmI, ApaI, TaqI) of gene VDR were examined with PCR-RFLP methodology. Statistical analysis was performed by using SPSS-17.0 program.

RESULTS

Results: Among patients with IATS who are carriers of the f/f genotype, FokI polymorphism of VDR gene by high thrombin time and a decrease in the rate of spontaneous fibrinolysis was registered. In individuals with the B/B genotype homozygous for the polymorphic variant, BsmI had significantly lower mean values of prothrombin and thrombin time and increased the rate of spontaneous fibrinolysis. The homozygotes for the A-allele ApaI polymorphism have 2.7 times higher risk of developing blood hypercoagulation than homozygotes for the a-allele was found.

CONCLUSION

Conclusions: Biochemical signs of hypercoagulation syndrome among patients with IATS who are carriers of the f/f genotype of the FokI polymorphic variant and among B/B homozygotes of the BsmI polymorphic variant and homozygotes for the A-allele of the AрaI polymorphism of the VDR gene were registered.

Pre-treatment spectral CT combined with CT perfusion can predict hemorrhagic transformation after thrombolysis in patients with acute ischemic stroke

OBJECTIVE

To investigate the value of pre-treatment spectral CT angiography (CTA) in predicting hemorrhagic transformation (HT) after intravenous thrombolysis (IVT) treatment in acute ischemic stroke (AIS) patients.

MATERIALS AND METHODS

AIS patients who underwent IVT with recombinant tissue plasminogen activator and pre-treatment head and neck spectral CTA and head CT perfusion (CTP) from January 2018 to June 2020 were reviewed retrospectively. Finally, 20 patients were included in the HT group and 22 age-matched patients were included in the non-HT group. Spectral and CTP parameters of the region of interest on pre-treatment CTA axial raw images and CTP images, including the infarct core (IC) and ischemic penumbral (IP) regions, were recorded. The differences in clinical variables, CTP, collateral scores and spectral parameters between the two groups were analyzed. Three multivariate logistic regression models were then developed, where model 1 included clinical and spectral parameters, model 2 included clinical and CTP parameters and a combined model included clinical, CTP, and spectral parameters. Receiver operating characteristic analysis was used to evaluate the performance of the multivariate model.

RESULTS

Patients with HT had higher Safe Implementation of Treatments in Stroke (SITS) score (p = 0.023), the volume of perfusion lesions (p = 0.005), the volume of IP (p = 0.003), the mean transit time (MIT) in the IC area (p = 0.012), as well as the TTP in IP area (p = 0.015) compared with patients without HT. The HT group showed significantly lower CBF in the IC area (p = 0.019), iodine concentration (p = 0.017) and the effective atomic number (p = 0.024) in the IP area than non-HT group. And the slope of the spectral curve of the HT group in the IP region was larger than that of the non-HT group (p = 0.023). Gender, age, SITS score, the volume of entire perfusion lesion, CBF and MIT in the IC area, TTP in the IP area, as well as iodine concentration in the IP area were included in the final multivariate model for predicting HT. And CBF in the IC area (OR = 0.779, 95 % CI:0.609-0.996, p = 0.046) as well as the iodine concentration of IP area (OR = 0.343, 95 % CI: 0.131-0.901, p = 0.030) were proved to be independent predictors for HT. The combined model including clinical, spectral, and CTP parameters, showed improved accuracy compared to the other two models, while the Delong test did not suggest a statistically significant difference (both p values > 0.05).

CONCLUSIONS

The iodine concentration of IP area derived from pre-treatment spectral CTA was an independent predictor of HT after IVT treatment for AIS patients. Moreover, multivariate models combined with clinical, spectral, and CTP parameters may be able to predict HT.

Intracranial Arterial Calcifications: Potential Biomarkers of Stroke Risk and Outcome

Intracranial artery calcifications (IAC), a common and easily identifiable finding on computed tomorgraphy angiography (CTA), has gained recognition as a possible risk factor for ischemic stroke. While atherosclerosis of intracranial arteries is believed to be a mechanism that commonly contributes to ischemic stroke, and coronary artery calcification is well-established as a predictor of both myocardial infarction (MI) and ischemic stroke risk, IAC is not currently used as a prognostic tool for stroke risk or recurrence. This review examines the pathophysiology and prevalence of IAC, and current evidence suggesting that IAC may be a useful tool for prediction of stroke incidence, recurrence, and response to acute ischemic stroke therapy.

Prognostic values of serum alkaline phosphatase and globulin levels in patients undergoing intravenous thrombolysis

Background

In previous studies, alkaline phosphatase (ALP) level was a prognostic factor for patients with ischemic stroke, and globulin level was associated with hemorrhagic transformation (HT) after intravenous thrombolysis (IVT). However, the association between these serum biomarkers and prognosis in patients with acute ischemic stroke (AIS) who undergo IVT remains unclear. This study aimed to investigate the characteristics of serum ALP and globulin levels after IVT and to assess the relationship between these serum biomarkers and prognosis.

Materials and methods

This retrospective study used a prospectively collected database. We included patients with AIS who received recombinant tissue plasminogen activator (rt-PA) IVT. Demographic information, vascular risk factors, laboratory test results, and other stroke-related data were collected for analysis. Clinical outcomes included HT and 3-month poor outcome (modified Rankin Scale scores ≥ 2) after IVT. The association of ALP and globulin levels with HT and poor outcome was investigated using multivariate logistic regression analysis. An individualized prediction model based on ALP and globulin levels for functional outcomes was established.

Results

We enrolled 750 patients in this study; 452 patients (60.3%) had poor outcome, and 117 patients (15.6%) had HT after IVT. After adjusting for all confounders, serum globulin level [OR = 1.055; 95% confidence intervals (CI): 1.006–1.107; P = 0.028] was independently associated with HT in patients with IVT. Serum ALP (OR = 1.009; 95% CI: 1.002–1.016; P = 0.010) and globulin levels (OR = 1.062; 95% CI: 1.020–1.107; P = 0.004) were associated with 3-month poor outcome in these patients. The constructed individualized prediction model for the 3-month poor outcome comprised the National Institutes of Health Stroke Scale (NIHSS) score, Trial of Org 10172 in Acute Stroke Treatment (TOAST), history of antihypertensive therapy, ALP and globulin levels. The area under the curve of the training and validation sets were 0.726 and 0.706, respectively, revealing that the model had good discriminating power. The P-values for the Hosmer-Lemeshow test in the training and validation sets were 0.978 and 0.148, respectively, indicating the model had good calibration.

Conclusion

This study found that higher serum globulin levels were independently associated with HT. Additionally, higher serum ALP and globulin levels were independently associated with a poor outcome in patients after IVT.

Carotid Siphon Calcification Predicts the Symptomatic Progression in Branch Artery Disease With Intracranial Artery Stenosis

Arterial calcification in the aortic arch, carotid bifurcation, or siphon on computed tomography was associated with cardiovascular disease. The association between arterial calcification prevalence and progression of branch atheromatous disease (BAD) in intracranial artery atherosclerosis was little investigated.

Silent brain infarction is associated with carotid siphon calcification in ischemic stroke patients

BACKGROUND

Silent brain infarction (SBI) had a higher prevalence in ischemic stroke patients than healthy population. Intracranial artery calcification, as the important component of atherosclerosis, is a known risk factor of ischemic stroke. Whether it is also the risk factor of SBI is uncertain. We aimed to assess the association between SBI and carotid siphon calcification (CSC) in ischemic stroke patients.

METHODS

We retrospectively collected consecutive data of acute ischemic stroke patients with and without SBI by Magnetic Resonance Imaging (MRI) and calcification using non-contrast Computerized Tomography (NCCT). We used a histopathologically validated method to score the circularity, thickness, and morphology of calcification. Clinical characteristics, prevalence and pattern (intimal and medial) of CSC were compared between patients with and without SBI. The association of CSC and SBI was investigated by logistic regression analysis.

RESULTS

Totally, 303 acute ischemic stroke patients were enrolled, of whom 260 (85.8%) had CSC. Patients with SBI were older (64.5 ± 10.4 years vs. 61.3 ± 12.1 years, P = 0.032), had a higher proportion of hypertension (77.5% vs. 65.7%, P = 0.035). Of the 260 CSC patients, there's no significant difference except for hyperlipidemia between patients with SBI and without SBI. The prevalence of intimal pattern of CSC was higher in those with SBI (adjusted odds ratio 2.42, 95% CI 1.219-4.794).

CONCLUSIONS

Patients with SBI at acute phase of ischemic stroke have more risk factors than mentioned previously. SBI associated with the intimal pattern of CSC which relate to the atherosclerosis process in symptomatic ischemic stroke patients.

Arterial Calcification and Its Association With Stroke: Implication of Risk, Prognosis, Treatment Response, and Prevention

Stroke is a leading cause of death worldwide. Vascular calcification (VC), defined as deposition of calcium-phosphate complexes in the vessels, is considered as the characteristic of vascular aging. Calcifications at different vessel layers have different implications. Intimal calcification is closely related to atherosclerosis and affects plaque stability, while medial calcification can cause arterial stiffening and reduce compliance. Accumulating evidence suggested that arterial calcifications, including calcifications in the intracranial artery, coronary artery, and carotid artery, are associated with the risk, prognosis, and treatment response of stroke. VC can not only serve as a marker of atherosclerosis, but cause cerebral hemodynamic impairment. In addition, calcifications in large arteries are associated with cerebral small vessel disease. In this review, we summarize the findings of recently published studies focusing on the relationship between large artery calcification and the risk, prognosis, treatment response, and prevention of stroke and also discuss possible mechanisms behind those associations.

Histology-Verified Intracranial Artery Calcification and Its Clinical Relevance With Cerebrovascular Disease

Intracranial artery calcification (IAC) was regarded as a proxy for intracranial atherosclerosis (ICAS). IAC could be easily detected on routine computer tomography (CT), which was neglected by clinicians in the previous years. The evolution of advanced imaging technologies, especially vessel wall scanning using high resolution-magnetic resonance imaging (HR-MRI), has aroused the interest of researchers to further explore the characteristics and clinical impacts of IAC. Recent histological evidence acquired from the human cerebral artery specimens demonstrated that IAC could mainly involve two layers: the intima and the media. Accumulating evidence from histological and clinical imaging studies verified that intimal calcification is more associated with ICAS, while medial calcification, especially the internal elastic lamina, contributes to arterial stiffness rather than ICAS. Considering the highly improved abilities of novel imaging technologies in differentiating intimal and medial calcification within the large intracranial arteries, this review aimed to describe the histological and imaging features of two types of IAC, as well as the risk factors, the hemodynamic influences, and other clinical impacts of IAC occurring in intimal or media layers.

Comparison of symptomatic vertebrobasilar plaques between patients with and without Diabetes Mellitus using computed tomographic angiography and vessel wall magnetic resonance imaging

OBJECTIVES

Diabetes mellitus is significantly associated with posterior circulation ischemic stroke. We aimed to compare the characteristics of vertebrobasilar plaques in symptomatic patients with and without diabetes using high-resolution vessel wall magnetic resonance imaging and computed tomographic angiography.

METHODS

From April 2017 to May 2021, cases from patients with transient ischemic attack or stroke in the posterior circulation territory who underwent high-resolution vessel wall magnetic resonance imaging and computed tomographic angiography were reviewed. Characteristics of culprit vertebrobasilar plaques were compared between patients with and without diabetes. Multivariate regression analysis was performed to assess the correlation between culprit plaque characteristics and diabetes.

RESULTS

A total of 148 patients were included and 75 patients were diagnosed with diabetes mellitus. Patients with diabetes had more intraplaque hemorrhage, calcification, spotty calcification presence, and higher calcification volume (all p < 0.05) compared with those without diabetes. Multivariate analysis demonstrated differences in the presence of intraplaque hemorrhage (p = 0.045) and number of spotty calcifications (p = 0.047) were statistically significant after adjusting for baseline characteristics.

CONCLUSIONS

Symptomatic patients with diabetes have a higher incidence of intraplaque hemorrhage and larger calcification burden than those without diabetes, indicating the association of diabetes with more advanced plaque features in the posterior circulation.

Intracranial Bleeding After Reperfusion Therapy in Acute Ischemic Stroke

Intracranial hemorrhage is one of the most feared complications following brain infarct. Ischemic tissues have a natural tendency to bleed. Moreover, the first recanalization trials using intravenous thrombolysis have shown an increase in mild to severe intracranial hemorrhage. Symptomatic intracerebral hemorrhage is strongly associated with poor outcomes and is an important factor in recanalization decisions. Stroke physicians have to weigh the potential benefit of recanalization therapies, first, with different risks of intracranial hemorrhage described in randomized controlled trials, and second with numerous risk markers that have been found to be associated with intracranial hemorrhage in retrospective series. These decisions have become quite complex with different intravenous thrombolytics and mechanical thrombectomy. This review aims to outline some elements of the pathophysiological mechanisms and classifications, describe most of the risk factors identified for each reperfusion therapy, and finally suggest future research directions that could help physicians dealing with these complications.