Cerebrovascular Stenosis Research Articles

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

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

Case report: Three characteristics of tyrosine kinase inhibitor-associated cerebrovascular stenosis. High threshold for infarction, atypical infarct area, and vascular recoverability under the use of ponatinib

While tyrosine kinase inhibitors (TKI)-associated cerebral vascular stenosis (CVS) exhibit distinct mechanisms compared to conventional stroke in basic research, the clinical strategy remains nearly the same other than TKI-switching. We present the case of a 22-year-old female with chronic myeloid leukemia without stroke risk factors, who developed ponatinib-associated CVS. Three potential characteristics of TKI-associated CVS were identified: a heightened threshold for infarction, an atypical infarct area, and vascular recoverability. Specifically, brain computed tomography remained normal despite 20 h of severe hemiplegia. The ischemic distribution was confined in gray matter and the anterior cerebral artery territory on magnetic resonance imaging, despite severe stenosis of the internal carotid artery. Ischemic changes resolved within 10 days and arterial stenosis improved after ponatinib withdrawal. These unique features, distinct from typical stroke, could lead to misdiagnosis as non-organic neurological disorders or other conditions in ponatinib-treated patients.

New evidence for fractional pressure ratio prediction by pulsatility index from transcranial Doppler in patients with symptomatic cerebrovascular stenosis disease.

The pulsatility index (PI) derived from transcranial Doppler (TCD) assessment may represent the cerebral resistance and altered cerebral blood flow. The purpose of this study was to assess the performance of the TCD PI in correlation with wire-based fractional pressure ratio (FPR). This study included 33 patients with symptomatic atherosclerotic lesions of the extracranial and intracranial large arteries, specifically the internal carotid artery, middle cerebral artery (MCA), vertebral artery (VA) V4 segment, and basilar artery (BA), all of which exhibited luminal stenosis ranging from 50% to 70%. TCD was performed prior to angiography in order to determine the flow distal to the lesion. We performed cerebrovascular angiography with a pressure wire to measure the FPR of vessels with stenotic lesions. Bland-Altman analysis and ordinal least square (OLS) linear regression were used to quantify the correlation between PI and FPR. A total of 42 TCD data points were analyzed. At the TCD locations distal to the lesions, the correlation coefficients were no less than 0.90%, with almost all P values <0.001, which indicated very strong positive correlations; the exception to this was the distal TCD for MCA segment lesions (r=0.897; P=0.015) and VA V4 segment (r=0.964; P=0.036). The Bland-Altman plot demonstrated a small difference (0.003) between the distal TCD PI and the FPR, with an acceptable 95% confidence interval [95% confidence interval (CI): 0.06-0.12]. The PI obtained through TCD assessment distal to the stenotic lesion exhibited a correlation with the FPR computed using pressure wire measurements.

Moyamoya disease mimicking primary central nervous system vasculitis: A case report

Rationale: Both Moyamoya disease (MMD) and primary central nervous system vasculitis (PCNSV) cause cerebrovascular stenosis resulting in similar ischemic neurological events, although therapeutic approaches are distinct from each other. High-resonance vascular wall imaging (HRVWI) with contrast-enhanced magnetic resonance imaging (MRI) is believed to be useful to differentiate PCNSV from MMD by detecting enhancement of cerebral vascular walls. However, recent studies have reported that the vascular walls of major arteries and superficial cerebral arteries are also enhanced by HRVWI in some MMD cases. Patient concerns: A 40-year-old Chinese woman admitted to our hospital with transient weakness of the right hand for a week. A cerebral infarction of the left frontal lobe was detected by diffusion-weighted brain MRI. Magnetic resonance angiography demonstrated severe stenosis of the left middle cerebral artery (MCA) and extensive vascular narrowing. Magnetic resonance angiography incidentally taken 3 years before admission showed only a mild stenosis at the proximal portion of right MCA with intact left internal carotid artery (ICA) and MCA. Moreover, on HRVWI with contrast-enhanced MRI after admission, the wall of ICA was strongly enhanced, and the superficial cerebral arteries were also highly enhanced, which initially suggested PCNSV. Despite these findings, reticular blood vessels were confirmed by digital subtraction angiography, and p.R4810K polymorphism in the ring finger protein 213 gene was detected. Diagnosis: Based on these result, the patient was diagnosed with MMD. Interventions: Bypass surgery was performed. Outcomes: Ischemic events have never been experienced since surgery. Lessons: Our MMD case demonstrated marked asymmetrical progression of cerebral artery stenosis, and enhanced vascular walls of ICA and superficial cerebral arteries by HRVWI, which made differential diagnosis from PCNSV difficult. Genetic analysis of SNP in the ring finger protein 213 gene should be performed to rule out MMD to avoid misdiagnosis of PCNSV particularly in Asian population.

Fast Computational Approaches to Derive Fractional Pressure Ratio in Patients with Extracranial or Intracranial Symptomatic Stenosis

We aimed to evaluate the performance of fast and straightforward μQFR computation in cerebrovascular stenosis lesions. A total of 30 patients with symptomatic stenosis lesions of 50-70% luminal stenosis and underwent FPR assessment at our hospital were included in this study. μQFR was applied to the interrogated vessel. An artificial intelligence algorithm was proposed for automatic delineation of lumen contours of cerebrovascular stenosis. We used invasive fractional pressure ratios (FPRs) as a reference standard. Pearson's correlation coefficient (r) was used to assess the correlation strength between μQFR and FPR, while Bland-Altman plots were used to evaluate the agreement between μQFR and FPR. An analysis of receiver-operating characteristics (ROC) was used to evaluate the performance of μQFR. Our result displayed strong positive correlations (r = 0.92; p<0.001) between μQFR and pressure wire FPR. An excellent agreement was observed between μQFR and FPR with a mean difference of 0.01 + 0.08; p=0.263; range from -0.16 to 0.14. The overall accuracy for identifying an FPR of <0.7 was 92% (95% CI: 85% to 100%). The area under the receiver-operating characteristic curve was higher for μQFR (0.92 [95% CI: 0.81 to 0.98]) than diameter stenosis (DS) (0.88 [95% CI: 0.75 to 0.95]. The positive likelihood ratio was 3.9 for μQFR with a negative likelihood ratio of 0, respectively. The μQFR computation has a strong correlation and agrees with the FPR calculated from the pressure wire. Therefore, μQFR may provide an essential therapeutic aid in patients with symptomatic stenosis lesions.

LC-MS/MS based metabolomic analysis of serum from patients with cerebrovascular stenosis

Cerebrovascular stenosis (CVS) is the main cause of ischemic stroke, which greatly threatens human life. Hence, it’s important to perform early screenings for CVS. Metabolomics is an emerging omics approach that has great advantages in disease screening and diagnosis. Therefore, we aim to elucidate the correlation between CVS and metabolomics, which can aid in conducting CVS screening at an early stage. Patients with CVS in Beijing Hospital were included in the study. A total of 36 participants, including 18 patients diagnosed with CVS and 18 healthy individuals, were recruited at Beijing Hospital between May 2022 and October 2021. The serum samples were analyzed for liquid chromatography-tandem mass spectrometry (LC-MS/MS). Then, multivariate statistical methods, including principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) were performed. Differential metabolites were obtained and demonstrated by volcano plot and heatmap. The study recruited 36 participants, including 18 patients with CVS and 18 healthy participants. A total of 150 metabolites were identified. Multivariate statistical analysis revealed significant differences between patients and healthy participants. Furthermore, 30 serum metabolites levels differed significantly between two groups. Differential metabolites were enriched in phenylalanine, tyrosine, and tryptophan biosynthesis; primary bile acid biosynthesis, and other pathways. This study identified differential metabolites in patients with CVS and elucidated the relevant metabolic pathways. Thus, these findings aid in the study of the pathogenesis of CVS and its early diagnosis. Data Availability StatementThe datasets generated for this study are available on request to the corresponding author.

Sex difference in cerebral atherosclerotic stenosis in Chinese asymptomatic subjects

Background and purposeSex difference in cerebral atherosclerosis has been noted in previous studies, but the precise characteristics remain incompletely elucidated. This study aims to identify the sex difference in patients with asymptomatic cerebrovascular stenosis. Materials and methodsThe image and clinical data of 1305 consecutive patients who had head and neck computed tomography angiography (CTA) were collected. Fifty hundred and seventy-three patients (287 males) with asymptomatic atherosclerotic stenosis in cerebral arteries were finally included. The stenosis number, distribution, severity and their changes with age were analyzed and compared between males and females. Simple linear regression was used to assess the change in lesions with age. ResultsA total of 2097 stenoses were identified in 573 patients, males had more stenoses than females (3 [2, 5] vs 3 [2, 4], p=0.015). The number of stenoses in extracranial arteries was much higher in males (p = 0.001). Females had higher percentage of stenosis in anterior (89.6% vs 85.9%, p = 0.012) and intracranial arteries (63.3% vs 57.1%, p = 0.004) than males. Males had higher percentage of moderate-severe stenosis (5.1% vs 3.2%, p = 0.026). Age (OR = 1.67; 95% CI 1.24–2.25; p < 0.001) and hypertension (OR = 2.53; 95% CI 1.24–5.15; p = 0.01) were associated with moderate-severe stenosis. In patients over 50 years old, the number of stenoses increased by 1.03 per 10 years (p < 0.001), with 0.72 more stenoses in males (p = 0.003). ConclusionsCerebral atherosclerotic stenosis was different between sexes regarding the distribution, severity and the change pattern with age, which underline the sex specific management in patients with cerebral atherosclerosis.

Association between DIAPH1 variant and posterior circulation involvement with Moyamoya disease

Moyamoya disease (MMD) is a chronic and progressive cerebrovascular stenosis or occlusive disease that occurs near Willis blood vessels. The aim of this study was to investigate the mutation of DIAPH1 in Asian population, and to compare the angiographic features of MMD patients with and without the mutation of the DIAPH1 gene. Blood samples of 50 patients with MMD were collected, and DIAPH1 gene mutation was detected. The angiographic involvement of the posterior cerebral artery was compared between the mutant group and the non-mutant group. The independent risk factors of posterior cerebral artery involvement were determined by multivariate logistic regression analysis. DIAPH1 gene mutation was detected in 9 (18%) of 50 patients, including 7 synonymous mutations and 2 missense mutations. However, the incidence of posterior cerebral artery involvement in mutation positive group was very higher than that in mutation negative group (77.8% versus 12%; p = 0.001). There is an association between DIAPH1 mutation and PCA involvement (odds ratio 29.483, 95% confidence interval 3.920–221.736; p = 0.001). DIAPH1 gene mutation is not a major genetic risk gene for Asian patients with moyamoya disease but may play an important role in the involvement of posterior cerebral artery.

Intracranial Spotty Calcium Predicts Recurrent Stroke in Patients with Symptomatic Intracranial Atherosclerotic Stenosis

PurposeAccumulating evidence highlights the association of calcium characteristics and cardiovascular events, but its role in cerebrovascular stenosis has not been well studied. We aimed to investigate the contribution of calcium patterns and density to recurrent ischemic stroke in patients with symptomatic intracranial atherosclerotic stenosis (ICAS).MethodsIn this prospective study, 155 patients with symptomatic ICAS in the anterior circulation were included, and all subjects underwent computed tomography angiography. The median follow-up for all patients was 22 months and recurrent ischemic stroke were recorded. Cox regression analysis was performed to examine whether calcium patterns and density were associated with recurrent ischemic stroke.ResultsDuring the follow-up, 29 patients who experienced recurrent ischemic stroke were older than those without recurrent ischemic stroke (62.93 ± 8.10 years vs. 57.00 ± 12.07 years, p = 0.027). A significantly higher prevalence of intracranial spotty calcium (86.2% vs. 40.5%, p < 0.001) and very low-density intracranial calcium (72.4% vs. 37.3%, p = 0.001) were observed in patients with recurrent ischemic stroke. Multivariable Cox regression analysis showed that intracranial spotty calcium, rather than very low-density intracranial calcium, remained an independent predictor of recurrent ischemic stroke (adjusted hazard ratio 5.35, 95% confidence interval 1.32–21.69, p = 0.019).ConclusionIn patients with symptomatic ICAS, intracranial spotty calcium is an independent predictor of recurrent ischemic stroke, which will further facilitate risk stratification and suggest that more aggressive treatment should be considered for these patients.

Relations between antinuclear, antineutrophil cytoplasmic, anticardiolipin antibodies and degree of neurological deficit, cerebrovascular stenosis in cerebral infarction patients.

To investigate the correlation of antinuclear antibody (ANA), antineutrophil cytoplasmic antibody (ANCA) and anticardiolipin antibody (ACA) with the degree of the neurological defect and cerebrovascular stenosis in patients with cerebral infarction. Clinical data of 99 patients with acute cerebral infarction (ACI) admitted to the Department of Neurology of Baoding First Central Hospital from June 2020 to December 2021 were retrospectively analyzed, and their ANA, ACA, ANCA, neurological deficit (NIHSS) scores as well as cerebrovascular stenosis were detected and assessed. Moreover, the correlation between the positive expression rates of ANA, ANCA, ACA and the degree of the neurological deficit, as well as the location and degree of cerebrovascular stenosis, were analyzed. All patients had ANA, ACA, ANCA antibodies with positive rates of 68.69%, 70.71%, 69.70%, and mild, moderate, and severe cerebrovascular stenosis with incidence rates of 28.28%, 32.32%, and 39.39% respectively; Moreover, their incidence of mild, moderate, and severe neurological deficits were 15.15%, 44.44%, and 40.40%, respectively. Statistically significant differences could be observed in the degree of cerebrovascular stenosis and neurological deficit between the ANA, ACA and ANCA antibody positive group and the negative group (p<0.05). ANA, ACA, ANCA antibody positive was moderately positively correlated with cerebrovascular stenosis rate and NIHSS score (0.40<r<0.60, p<0.05). The positive rates of ANA, ACA and ANCA antibodies were higher in patients with ACI, which was closely correlated with the degree of cerebrovascular stenosis and neurological deficit.

Frequency of Asymptomatic Intracranial and Extracranial Arterial Stenosis in a Group of Healthy General Papulation in Kerman (South of Iran).

This study aimed to investigate the frequency of asymptomatic intracranial and extracranial artery stenosis in healthy volunteers in Kerman, Iran, in 2019 using Doppler ultrasound imaging. This cross-sectional study was conducted on healthy volunteers in Kerman in 2019 following a public elicitation. After the general examination, 138 healthy volunteers who had no history of any disease and were not treated with any medication underwent cerebrovascular evaluation with Doppler ultrasound. Demographic information, history of addiction, and sonographic findings were recorded in a checklist and then analyzed using SPSS 22. Stenosis was found in 14.4% of volunteers. The mean age of participants was 45.8±10.12 years, and 74 (54%) of them were male. In volunteers with stenosis, a significant correlation was found between age (P = 0.03) and addiction (P = 0.04) with the involved artery. There was also a significant correlation between addiction and intracranial and extracranial artery stenosis (P = 0.04). Logistic regression analysis showed a significant relationship between being female, addiction, and age with stenosis, as well as between addiction and intracranial artery stenosis (P <0.05). The majority of healthy residents of Kerman have asymptomatic cerebrovascular stenosis, and this is more prevalent in the elderly, addicts, and women.

A novel computational fluid dynamic method and validation for assessing distal cerebrovascular microcirculatory resistance

Background and objectiveThe non-invasive assessment of microcirculatory resistance could improve the treatment of cerebrovascular stenosis. This study aimed to validate a novel computational strategy for determining the reference value of microcirculatory resistance in patients with cerebrovascular stenosis. MethodsWe reconstructed a patient-specific 3-dimensional model of the extracranial-intracranial arteries. A computational strategy incorporating patient-specific pressure-wire measurements was developed to estimate the blood flow rate and microcirculatory resistance. Throughout the computational fluid dynamics (CFD) simulation, the boundary conditions were adjusted according to the developed algorithm. Pearson correlation and Bland-Altman analyses were used to quantify the correlation and agreement between CFD calculations and transcranial Doppler (TCD) assessment. ResultsA strong correlation was found between the CFD-based and invasive distal pressure measurements (P<0.0001). Meanwhile, the CFD and TCD-based flow measurements were highly correlated (r = 0.853; P = 0.001). Furthermore, there was a correlation between the mean velocity measured by CFD and the mean velocity measured by TCD (r = 0.777; P<0.001). Good agreement was observed between the mass flow by CFD simulation and volumetric flow by TCD (P = 0.0266, mean difference: -0.7814 mmHg, limits of agreement, -4.0905 - 2.5276). However, the mean velocities from CFD simulation were in less agreement with those from the TCD assessment (P = 0.3992, mean difference, -0.0485; limits of agreement, -0.6141 - 0.5170). Results of the CFD simulation indicate that the flow resistance varies greatly between individuals. ConclusionsThe computational strategy of incorporating patient-specific pressure-wire measurements may serve as an effective approach to evaluate the actual reference values of microcirculatory resistance. In addition, an individualized assessment of non-invasive flow resistance is necessary for the accurate determination of non-invasive cerebrovascular pressure.

The Utility of Arterial Transit Time Measurement for Evaluating the Hemodynamic Perfusion State of Patients with Chronic Cerebrovascular Stenosis or Occlusive Disease: Correlative Study between MR Imaging and 15O-labeled H2O Positron Emission Tomography.

To verify whether arterial transit time (ATT) mapping can correct arterial spin labeling-cerebral blood flow (ASL-CBF) values and to verify whether ATT is a parameter that correlates with positron emission tomography (PET)-oxygen extraction fraction (OEF) and PET-mean transit time (MTT). Eleven patients with unilateral major cerebral artery stenosis or occlusion underwent MRI and PET in the chronic or asymptomatic phase. ASL-MRI acquisitions were conducted with each of two post-label delay (PLD) settings (0.7s and 2.0s) using a pseudo-continuous ASL pulse sequence and 3D-spin echo spiral readout with vascular crusher gradient. ATT maps were obtained using a low-resolution pre-scan approach with five PLD settings. Using the ASL perfusion images and ATT mapping, ATT-corrected ASL-CBF images were obtained. Four kinds of ASL-CBF methods (PLD 0.7s with or without ATT correction and PLD 2.0s with or without ATT correction) were compared to PET-CBF, using vascular territory ROIs. ATT and OEF were compared for all ROIs, unaffected side ROIs, and affected side ROIs, respectively. ATT and MTT were compared by the ratio of the affected side to the unaffected side. Transit time-based ROIs were used for the comparison with ATT. Comparing ASL-CBF and PET-CBF, the correlation was higher with ATT correction than without correction, and for a PLD of 2.0s compared with 0.7s. The best correlation was for PLD of 2.0s with ATT correction (R2 = 0.547). ROIs on the affected side showed a low but significant correlation between ATT and PET-OEF (R2 = 0.141). There was a low correlation between the ATT ratio and the MTT ratio (R2 = 0.133). Low-resolution ATT correction may increase the accuracy of ASL-CBF measurements in patients with unilateral major cerebral artery stenosis or occlusion. In addition, ATT itself might have a potential role in detecting compromised hemodynamic state.

Impact of magnetic resonance angiography parameters on stroke prevention therapy in pediatric patients with sickle cell anemia.

Degree of cerebrovascular stenosis in pediatric patients with sickle cell anemia (SCA) informs need for chronic transfusion therapy, which has significant risks. Flow artifact, intrinsic to magnetic resonance angiography (MRA), is dependent on technical parameters and can lead to overinterpretation of stenosis. The primary objective of this study was to document any change in stroke prevention therapy that could be attributed to the implementation of a standardized MRA scanning protocol for patients with SCA. A standardized MRA scanning protocol with an echo time of less than 5ms was implemented at Montefiore Medical Center (MMC), NY in May 2016. Retrospective chart review identified 21 pediatric patients with SCA, with an MRA head both pre- and post-May 2016. Arterial stenosis on MRA, machine parameters, and treatment plans were compared pre- and post-implementation. Ten of the 21 patients met inclusion criteria. Previously seen stenosis was re-classified to a lower degree in six of the 10 patients, leading to discontinuation of transfusions in five patients. No patients required escalation of therapy to chronic transfusions. Optimizing flow artifact by decreasing echo time to less than 5ms can improve accurate interpretation of cerebrovascular disease, and ensure appropriate treatment plans are in place for stroke prevention. This is especially important for implementing "TCD With Transfusions Changing to Hydroxyurea (TWiTCH)" clinical trial results in the real-world setting.

Impact of MRA Echo Time on Stroke Prevention Therapy in Pediatric Patients with Sickle Cell Disease

Background and Purpose: Magnetic Resonance Angiography (MRA) is performed on pediatric patients with sickle cell disease (SCD) to classify degree of cerebrovascular stenosis, informing stroke risk and treatment plan for stroke prevention. Flow artifact intrinsic to MRA and influenced primarily by TE (echo time) can lead to overinterpretation of stenosis. A standardized MRA protocol with shorter TE for patients with sickle cell disease was implemented at our institution. The primary objective of this study was to document any change in stroke prevention therapy that could be attributed to the implementation of this standardized MRA scanning protocol. Methods: A standardized MRA scanning protocol with an TE of <5msec based on the SWiTCH study protocol for patients with SCD was implemented at Montefiore Medical Center, NY (MMC) May 2016. This project included a retrospective chart review of patients at MMC ≤ 21 years with SCD who had one MRA head pre- AND one MRA post-May 2016. Of the 81 patients that met inclusion criteria, 29 patients were found to have vasculopathy on pre-May 2016 imaging and were included in this analysis. Level of arterial stenosis on MRA, TE, and treatment plans were documented both pre- and post-May 2016. McNemar analysis was used to determine the significance of change in treatment plans before and after implementation of the standardized scanning protocol. Results: 24/29 (83%) patients were on chronic transfusion therapy for CNS vasculopathy pre-May 2016 whereas 18/29 (62%) were on chronic transfusion therapy post May 2016. Notably, 6 patients had a resolution of vasculopathy on MRA post implementation of the scanning protocol, leading to discontinuation of chronic transfusion therapy. McNemar analysis showed this difference to be statistically significant (p = 0.042). Conclusion: Implementing a standardized MRA scanning protocol allowed for chronic transfusion therapy to be discontinued in 6 out of 24 patients due to minimizing flow artifact. Screening for arterial stenosis with TE <5msec can improve accurate interpretation of true cerebrovascular disease and ensure appropriate treatment plans are in place for SCD stroke prevention.

Thrombus Inhibition and Neuroprotection for Ischemic Stroke Treatment through Platelet Regulation and ROS Scavenging.

Ischemic stroke is caused by cerebrovascular stenosis or occlusion. Excessive reactive oxygen species (ROS) are the focus-triggering factor of irreversible injury in ischemic regions, which result in harmful cascading effects to brain tissue, such as inflammation and microthrombus formation. In the present work, we designed nanodelivery systems (NDSs) based on MnO2 loaded with Ginkgolide B (GB) for restoring the intracerebral microenvironment in ischemic stroke, such as ROS scavenging, O2 elevation, thrombus inhibition and damage repair. GB can activate the endogenous antioxidant defense of cells by enhancing the nuclear factor-E2-related factor 2 (Nrf2) signalling pathway, thus protecting brain tissue from oxidative damage. However, the blood-brain barrier (BBB) is also a therapeutic obstacle for the delivery of these agents to ischemic regions. MnO2 nanoparticles have an inherent BBB penetration effect, which enhances the delivery of therapeutic agents within brain tissue. MnO2 , with mimicking enzymatic activity, can catalyze the decomposition of overproduced H2 O2 in the ischemic microenvironment to O2 , meanwhile releasing platelet-antagonizing GB molecules, thus alleviating cerebral hypoxia, oxidative stress damage, and microthrombus generation. This study may provide a promising therapeutic route for regulating the microenvironment of ischemic stroke through a combined function of ROS scavenging, microthrombus inhibition, and BBB penetration.

Cerebral Protection of Intraoperative Infusion of Dexmedetomidine in Patients with Chronic Cerebrovascular Stenosis Undergoing Endovascular Interventional Therapies: A Prospective Randomized Controlled Trial

To investigate the cerebral protective effect of intraoperative dexmedetomidine infusion on patients with chronic cerebral vascular stenosis receiving endovascular interventional therapy. Sixty patients with carotid artery or cerebral artery stenosis or occlusion stenting under elective general anesthesia were divided into dexmedetomidine group (group D) and normal saline group (group N). Group D was given dexmedetomidine loading dose 1.0μg/kg after peripheral vein opening for 10min, and then adjusted infusion rate to 0.5μg/kg/h until stopped 30min before end. At 7days after operation, the contents of S100β, neuron-specific enolase (NSE) and interleukin-6 (IL-6) in group D were apparently lower than those in group N (P<0.05), while the contents of IL-1β and tumor necrosis factor-α in 2 groups showed no statistical significance (P>0.05). Additionally, at 4days and 7days after operation, the scores of Mini-Mental State Scale (MMSE) and Wechsler Memory Scale (WMS) in group D were significantly higher than those in group N (P<0.05). Thirtydays after surgery, the cerebral hemodynamic indexes (relative mean transit time, relative time to peak) in group D were significantly improved, and obviously better than those in group N (P<0.05). The S-100β, NSE, and inflammatory mediator IL-6 in group D were significantly decreased compared with group N, the MMSE and WMS cognitive function scores, and the cerebral blood perfusion were apparently improved in group D, clarifying dexmedetomidine has protective effect on nerve tissue injury by inhibiting inflammation.

Risk Factors and Imaging Biomarkers Associated With Perioperative Stroke in Pediatric Moyamoya Arteriopathy.

Patients with moyamoya arteriopathy are at high risk for developing ischemic stroke in the perioperative period. We sought to evaluate whether preoperative clinical and neuroimaging biomarkers are associated with postoperative stroke and transient ischemic attack in children with moyamoya following revascularization surgery. We performed a retrospective chart review of pediatric patients who underwent revascularization surgery for moyamoya in the last 15 years. Fifty-three patients who underwent 69 surgeries met the inclusion criteria. We recorded clinical predictors of stroke or transient ischemic attack within 7 days following surgery. We used Suzuki stage and Composite Cerebrovascular Stenosis Score to analyze neuroimaging. Significant risk factors for developing postoperative stroke or transient ischemic attack were younger age at surgery (P = .004) and transient ischemic attack less than 1 month prior to surgery (P < .001). Children under 5 and those with recent preoperative ischemic events should be the focus of investigation to evaluate modifiable risk factors and targeted interventions.

Application of DTI and fMRI in moyamoya disease.

Moyamoya disease (MMD) is a chronic and progressive cerebrovascular stenosis or occlusive disease that occurs near Willis blood vessels. Diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) are used to detect the microstructure of white matter and the function of gray matter, respectively. The damage of these structures will lead to the change of cognitive level in patients with moyamoya disease. In this paper, the principles of DTI and fMRI, their applications and challenges in moyamoya disease are reviewed.

Preoperative Serum Alkaline Phosphatase and Neurological Outcome of Cerebrovascular Surgery.

This study evaluated the relationship between the preoperative alkaline phosphatase (ALP) level and major postoperative neurological complications in patients undergoing cerebral bypass surgery. This was a retrospective analysis of a prospective database of all patients undergoing cerebral bypass surgery after a diagnosis of cerebrovascular stenosis or occlusion between May 2003 and August 2017. The patients were divided into tertiles based on serum alkaline phosphatase (ALP) levels (low: <63, intermediate: 63~79, and high: ALP > 79 IU/mL). The incidence of neurological events according to ALP level was analyzed. The study analyzed 211 cases. The incidence of acute infarction was highest in the third serum ALP tertile (5.7% vs. 2.9% vs. 16.9% in the first, second, and third tertile, respectively, p = 0.007). Logistic regression analysis showed that the third tertile of serum ALP was an independent predictor of acute cerebral infarction (odds ratio 3.346, 95% confidence interval 1.026–10.984, p = 0.045). On Kaplan–Meier time-to-event curves, the incidence of acute infarction increased significantly with ALP (log rank = 0.048). Preoperative serum ALP level can be used as a biomarker to predict acute cerebral infarction in patients undergoing cerebral bypass surgery for vascular stenosis or occlusion.