Epidemiology of Moyamoya Disease in China: Single-Center, Population-Based Study

Advances in moyamoya disease: pathogenesis, diagnosis, and therapeutic interventions

Moyamoya disease (MMD) is a type of cerebrovascular disease characterized by occlusion of the distal end of the internal carotid artery and the formation of collateral blood vessels. Over the past 20 years, the landscape of research on MMD has significantly transformed. In this review, we provide insights into the pathogenesis, diagnosis, and therapeutic interventions in MMD. The development of high-throughput sequencing technology has expanded our understanding of genetic susceptibility, identifying MMD-related genes beyond RNF213, such as ACTA2, DIAPH1, HLA, and others. The genetic susceptibility of MMD to its pathological mechanism was summarized and discussed. Based on the second-hit theory, the influences of inflammation, immunity, and environmental factors on MMD were also appropriately summarized. Despite these advancements, revascularization surgery remains the primary treatment for MMD largely because of the lack of effective in vivo and in vitro models. In this study, 16 imaging diagnostic methods for MMD were summarized. Regarding therapeutic intervention, the influences of drugs, endovascular procedures, and revascularization surgeries on patients with MMD were discussed. Future research on the central MMD vascular abnormalities and peripheral circulating factors will provide a more comprehensive understanding of the pathogenic mechanisms of MMD.

Pregnancy Risk Assessment, Management, and Delivery Plan for Pregnant Women with Moyamoya Disease Using a Multidisciplinary Collaborative Approach: A Case Series

Purpose

This case report aimed to summarize the risk factors, clinical characteristics, imaging changes, and maternal and fetal prognosis associated with Moyamoya disease in pregnant women and to explore effective management strategies and a comprehensive delivery plan.

Case Presentation

The clinical data of four pregnant women who were diagnosed with Moyamoya disease and admitted to our hospital between January 2010 and January 2019 were retrospectively analyzed. Their diagnosis, treatment, delivery, and postpartum management during the pregnancy were analyzed. Among the four pregnant women, three were primipara and one was multipara. The age ranged from 27 to 41 years old. The gestational week of termination of pregnancy ranged between 8 and 39 weeks. During pregnancy, one case died in utero; one case was complicated with postpartum hemorrhage; one case was complicated with chronic hypertension, multiple cerebral artery stenosis and occlusion, bilateral middle cerebral artery occlusion, bilateral internal carotid artery occlusion, and Hashimoto's thyroiditis. Under epidural anesthesia, two cases underwent a lower segment cesarean section; one case underwent artificial abortion; and one case underwent induced labor during late pregnancy. Two newborns survived.

Conclusion

Moyamoya disease is a rare and serious complication of pregnancy. Pregnancy and childbirth may exacerbate the progression of this disease or induce cerebrovascular accidents, with a high mortality and disability rate, which seriously threatens the safety of mother and infant lives; however, with the close collaboration of a multidisciplinary team, it is possible to maximize a good pregnancy outcome.

Exosomal MicroRNAs: Biomarkers of moyamoya disease and involvement in vascular cytoskeleton reconstruction

Moyamoya disease currently lacks a suitable method for early clinical screening.This study aimed to identify a simple and feasible clinical screening index by investigating microRNAs carried by peripheral blood exosomes. Experimental subjects participated in venous blood collection, and exosomes were isolated using Exquick-related technology. Sequencing was performed on the extracted exosomal ribonucleic acids (RNAs) to identify differential microRNAs. Verification of the results involved selecting relevant samples from the genetic database. The study successfully pinpointed a potential marker for early screening, hsa-miR-328-3p + hsa-miR-200c-3p carried by peripheral blood exosomes. Enrichment analysis of target genes revealed associations with intercellular junctions, impaired cytoskeletal regulation, and increased fibroblast proliferation, leading to bilateral internal carotid artery neointimal expansion and progressive stenosis. These findings establish the diagnostic value of hsa-miR-328-3p+hsa-miR-200c-3p in screening moyamoya disease, while also contributing to a deeper understanding of its underlying pathophysiology. Significant differences in microRNA expressions derived from peripheral blood exosomes were observed between moyamoya disease patients and control subjects. Consequently, the utilization of peripheral blood exosomes, specifically hsa-miR-328-3p + hsa-miR-200c-3p, holds potential for diagnostic screening purposes.

Nonalcoholic fatty liver disease is an independent risk factor for ischemic stroke after revascularization in patients with Moyamoya disease: a prospective cohort study

BACKGROUND

The study aimed to investigate the association between nonalcoholic fatty liver disease (NAFLD) and ischemic stroke events after revascularization in patients with Moyamoya disease (MMD).

METHODS

This study prospectively enrolled 275 MMD patients from September 2020 to December 2021. Patients with alcoholism and other liver diseases were excluded. NAFLD was confirmed by CT imaging or abdominal ultrasonography. Stroke events and modified Rankin Scale (mRS) scores at the latest follow-up were compared between the two groups.

RESULTS

A total of 275 patients were enrolled in the study, among which 65 were diagnosed with NAFLD. Univariate logistic regression analysis showed that NAFLD (P = 0.029) was related to stroke events. Multivariate logistic regression analysis showed that NAFLD is a predictor of postoperative stroke in MMD patients (OR = 27.145, 95% CI = 2.031-362.81, P = 0.013). Kaplan-Meier analysis showed that compared with MMD patients with NAFLD, patients in the control group had a longer stroke-free time (P = 0.004). Univariate Cox analysis showed that NAFLD (P = 0.016) was associated with ischemic stroke during follow-up in patients with MMD. Multivariate Cox analysis showed that NAFLD was an independent risk factor for stroke in patients with MMD (HR = 10.815, 95% CI = 1.259-92.881, P = 0.030). Furthermore, fewer patients in the NAFLD group had good neurologic status (mRS score ≤ 2) than the control group (P = 0.005).

CONCLUSION

NAFLD was an independent risk factor for stroke in patients with MMD after revascularization and worse neurological function outcomes.

High lipoprotein(a) concentration is associated with moyamoya disease

BACKGROUND

Moyamoya disease (MMD) has attracted the attention of scholars because of its rarity and unknown etiology.

METHODS

Data for this study were sourced from the Second Affiliated Hospital of Nanchang University. Regression analyses were conducted to examine the association in Lipoprotein [Lp(a)] and MMD. R and IBM SPSS were conducted.

RESULTS

A cohort comprising 1012 MMD patients and 2024 controls was established through the propensity score matching method. Compared with controls, MMD patients showed higher median Lp(a) concentrations [18.5 (9.6-37.8) mg/dL vs. 14.9 (7.8-30.5) mg/dL, P < 0.001]. The odds ratios and 95% confidence intervals for Lp(a) were calculated in three models: unadjusted model, model 1 (adjusted for body mass index and systolic blood pressure), and model 2 (adjusted for model 1 plus triglyceride, C-reactive protein, homocysteine, and low-density lipoprotein cholesterol). Results were [1.613 (1.299-2.002), P < 0.001], [1.598 (1.286-1.986), P < 0.001], and [1.661 (1.330-2.074), P < 0.001], respectively. Furthermore, age, sex, or hypertension status had nothing to do with this relationship.

CONCLUSIONS

Positive relationship exists between Lp(a) and MMD.

Prevalence and Associations of Cognitive Impairment in Adult Patients with Moyamoya Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Cognitive impairment, and in the long term Alzheimer's disease, vascular, or mixed dementia, are potential complications of moyamoya disease (MMD), of which the prevalence and associations are not well established.

OBJECTIVE

We performed a systematic review and meta-analysis to investigate the prevalence of cognitive impairment in adult patients with MMD as well as its clinical and demographic correlates.

METHODS

We performed a systematic search of four electronic databases: PubMed (MEDLINE), EMBASE, Scopus, and Cochrane Library, profiling studies from inception until 7 May 2023. Clinical data consisting of population characteristics, comorbidities, cognitive assessment tools used, and prevalence of cognitive impairment was extracted.

RESULTS

Seventeen studies were included in the meta-analysis, with a total study population of 1,190 patients. All studies assessed cognition, and the overall prevalence of cognitive impairment in MMD patients was 54.59%. A subgroup analysis identified that the prevalence of executive dysfunction in MMD patients was 31.55%. We performed a meta-regression analysis which identified that cognitive impairment was not associated with age, education level, or a history of ischemic or hemorrhagic stroke.

CONCLUSIONS

A substantial proportion of MMD patients have cognitive impairment, and cognitive impairment was found to have no association with a history of stroke. Further research is necessary to investigate the longitudinal relationship of MMD and cognitive impairment, and the impact of bypass surgery on cognitive impairment.

Risk factors and a novel cerebral infarction extent scoring system for postoperative cerebral ischemia in patients with ischemic Moyamoya disease

Postoperative cerebral ischemic complication is the most common complication of revascularization surgery for patients with moyamoya disease (MMD). This retrospective study was conducted on 63 patients with ischemic MMD. Postoperative ischemia occurred in 15 of the 70 revascularization operations performed for patients after surgical revascularization, translating to an incidence of 21.4%. Univariate analysis revealed that onset infarction (p = 0.015), posterior cerebral artery involvement (p = 0.039), strict perioperative management (p = 0.001), interval time between transient ischemic attack (TIA) or infarction presentation and operation (p = 0.002) and preoperatively cerebral infarction extent score (CIES) (p = 0.002) were significantly associated with postoperative cerebral ischemia. Multivariate analysis revealed that strict perioperative management (OR = 0.163; p = 0.047), and preoperatively CIES (OR = 1.505; p = 0.006) were independently associated with postoperative cerebral ischemia-related complications. After comprehensive improvement of perioperative management protocol, the incidence of symptomatic infarction declined to 7.4% (4 out of 54). Analysis of the area under the receiver operating characteristic curve (AUROC) indicated CIES was a predictor for both postoperative ischemia and high follow-up modified Rankin Scale scores. In summary, strict perioperative management and CIES were identified as independent risk factors for postoperative ischemic complications in ischemic MMD, demonstrating that comprehensive and individualized perioperative management improve postoperative outcomes in patients with MMD. Furthermore, application of CIES to evaluate pre-existing cerebral infarction can improve the management of patients.

MicroRNA Expression in Circulating Leukocytes and Bioinformatic Analysis of Patients With Moyamoya Disease

Objective: MicroRNAs (miRNAs) in exosomes had been implicated differentially expressed in patient with moyamoya disease (MMD), but the miRNAs expression in circulating leukocytes remains unclear. This study was investigated on the differential expression of miRNAs in peripheral leukocytes between MMD patients and healthy adults, and among patients with subtypes of MMD.

Materials and methods: A total of 30 patients with MMD and 10 healthy adults were enrolled in a stroke center from October 2017 to December 2018. The gene microarray was used to detect the differential expression profiles of miRNA in leukocytes between MMD patients and controls, and the differentially expressed miRNAs were verified by the method of real-time PCR. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to explore the key signaling pathways and possible pathogenesis of MMD.

Results: The microarray results showed 12 differentially expressed miRNAs in leukocytes of MMD patients compared with controls (fold change &gt;2.0, p &lt; 0.05 and FDR &lt;0.05), of which 8 miRNAs were upregulated (miRNA-142-5p, miRNA-29b-3p, miRNA-424-5p, MiRNA-582-5p, miRNA-6807-5p, miRNA-142-3p, miRNA-340-5p, miRNA-4270), and 4 miRNAs were downregulated (miRNA-144-3p, miRNA-451a, miRNA-486-5p, miRNA-363-3p). The real-time PCR confirmed seven differentially expressed miRNAs (p &lt; 0.05), of which 4 miRNAs (miRNA-29b-3p, miRNA-142-3p, miRNA-340-5p, miRNA-582-5p) were upregulated, and 3 miRNAs (miRNA-363-3p, miRNA-451a and miRNA-486-5p) were downregulated. Both GO and KEGG analysis suggested that the Wnt signaling pathway may be involved in the pathogenesis of MMD. In addition, miRNAs were also differentially expressed among patients with subtypes of MMD.

Conclusion: This study indicated that miRNAs are differentially expressed in peripheral leukocytes between MMD patients and healthy adults, and among patients with subtypes of MMD. The Wnt signaling pathway is probably involved in the pathogenesis of MMD.

The contralateral progression in a cohort of Chinese adult patients with unilateral moyamoya disease after revascularization: a single-center long-term retrospective study

Background

Moyamoya disease (MMD) is a chronic progressive cerebrovascular disease mainly existing in the Asian population, which can be divided into unilateral and bilateral types. Contralateral progression has been reported in pediatric patients with unilateral MMD, while large series about contralateral progression in Chinese adult patients were rare. The goal of this study is to elucidate the clinical features and incidence of contralateral progression in Chinese MMD adult patients.

Methods

One hundred one Chinese adult patients with unilateral MMD who received surgery treatments between January 2015 and January 2017 in our hospital were enrolled in this study. This study contained 89 patients. Digital subtraction angiography was performed in all patients for initial diagnosis, and magnetic resonance angiography was repeated 6 months from the initial operation and then annually. Clinical characteristics, contralateral progression, and risk factors were studied. Previous related studies were also reviewed and meta-analyzed.

Results

Of these 89 patients, contralateral progression was identified in 8 patients (9.0%) within a median follow-up period of 63 months, which was lower than that in previous studies (25.9%). Single-factor analysis and multivariate analysis did not reveal significant risk factors related to the contralateral progression.

Conclusion

The progress rate in this cohort of Chinese adult patients with unilateral MMD after revascularization was 9.0%, which indicates that some of the unilateral MMD were an early form of bilateral MMD rather than a separate condition.

Trial registration.

This work was approved by the Medical Ethics Committee of Zhongnan Hospital of Wuhan University (approval number: Kelun-2017005).

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-022-05153-6.

Epidemiology of Moyamoya Angiopathy in Eastern India

Introduction

Moyamoya angiopathy (MMA) is a chronic, progressive intracranial vasculopathy with variation in prevalence and clinical manifestations across different populations. This study was aimed to estimate the frequency of MMA as an etiology of stroke and its epidemiological features in the largest cohort of MMA patients in India.

Method

A single-centered cross-sectional observational study over a period of 5 years (2016–2021) was undertaken among consecutive stroke and transient ischemic attack (TIA) patients to look for the presence of MMA angiographically. Each patient with angiographically proven MMA was further evaluated for demographic, clinical, and radiological characteristics.

Results

Among 10,250 consecutive stroke and TIA patients (ischemic = 78%, hemorrhagic = 22%), frequency of MMA was 1.56% (n = 160); 15.3% among children. Female preponderance (Male:Female = 1:1.4) was noted among 160 MMA patients, with bimodal age distribution, first peak at 3–8 years, and a shorter second peak at 41–47 years. Childhood-onset MMA was seen in 75 (46.9%) with commonest initial neurological symptom of fixed-motor-weakness (44.0%), followed by TIA (26.7%); while 85 (53.1%) had adult-onset MMA with fixed-motor-weakness (50.6%) followed by headache (24.7%) as the predominant initial neurological symptom; seizure significantly higher in children (p < 0.001) and headache in adults (p = 0.012). Transient and fixed neurological manifestations constituted 87.5 and 69.4% respectively, of symptoms throughout the disease course. Cerebral infarction (45.0%) and TIA (21.9%) were the commonest types of MMA. On brain imaging, infarction was noted in 80.6%, hemorrhage in 11.3%, significantly higher among adults (p < 0.001). Cortical infarct and Gyral pattern were commoner in children (p = 0.004), subcortical infarcts in adults (p = 0.018). Frequent Suzuki staging observed was stage 4 (31.3%), followed by stage 3 (30.0%). Involvement of posterior circulation was detected in 55.6%, brain atrophy at the time of diagnosis was seen in 65.0%.

Conclusion

MMA is an important etiological consideration in patients with stroke, especially in children. It can present with a myriad of transient neurological symptoms, frequently overlooked, leading to delayed diagnosis, and contributing to socio-economic burden. Indian MMA showed aberrations in its gender predisposition, age distribution, frequency of familial cases, disease manifestation, and type of stroke, in comparison to its Japanese and Caucasian counterparts pointing to the inter- and intra-continent differences of MMA phenotype. Future development of the Indian MMA national registry is of essence.

Epidemiology of Moyamoya disease in China: A nationwide hospital-based study

Background

The national epidemiologic data in mainland China is still absent for moyamoya disease (MMD).

Methods

This study was a nationwide hospital-based observational retrospective study to estimate epidemiological characteristics of MMD. The data was based on the Hospital Quality Monitoring System (HQMS), a national database which covers all tertiary hospitals in mainland China. This system consistently collects medical records including demographic characteristics, diagnoses, procedures, and expenses etc. for all inpatients. MMD was identified by ICD-10 code (I67·5) in HQMS.

Findings

A total of 47,443 new-onset patients with total 69,680 hospitalization records from 1312 hospitals during 2016 to 2018 were included. The annual incidence rate was 1·14 per 100,000 inhabitants (95% CI, 1·12–1·16) and approximately a 2-fold increase from 2016 to 2018. The incidence in children (0·18 per 100,000 inhabitants per year; 95% CI, 0·17–0·20) was significantly lower than that in adults (1·40 per 100,000; 95% CI, 1·38–1·42) (P<0·001) and the peak incidence was 45–54 years. The distribution model of incidence rate was presented as a clustered regional pattern (Moran's I = 0·155, P = 0·018, Z = 2·375) by global spatial correlation analysis.

Interpretation

Our study reported the annual incidence of MMD was 1·14 per 100,000 inhabitants in mainland China during 2016 to 2018, and it was increasing year by year. The geographical distribution of MMD incidence presented as a clustered regional pattern, which may provide new view for future study on the etiology for MMD.

Funding

National Natural Science Foundation of China and “13th Five-Year Plan” National Science and Technology Supporting Plan.

Progression in Moyamoya Disease: Clinical Feature, Neuroimaging Evaluation and Treatment

Moyamoya disease (MMD) is a chronic cerebrovascular disease characterized by progressive stenosis of the arteries of the circle of Willis, with the formation of collateral vascular network at the base of the brain. Its clinical manifestations are complicated. Numerous studies have attempted to clarify the clinical features of MMD, including its epidemiology, genetic characteristics, and pathophysiology. With the development of neuroimaging techniques, various neuroimaging modalities with different advantages have deepened the understanding of MMD in terms of structural, functional, spatial, and temporal dimensions. At present, the main treatment for MMD focuses on neurological protection, cerebral blood flow reconstruction, and neurological rehabilitation, such as pharmacological treatment, surgical revascularization, and cognitive rehabilitation. In this review, we discuss recent progress in understanding the clinical features, in the neuroimaging evaluation and treatment of MMD.

Case of de novo cerebral microbleeds in ischemic-type pediatric moyamoya disease

Background:

Studies on pediatric patients with moyamoya disease who presented with de novo cerebral microbleeds (CMBs) are extremely rare.

Case Description:

Herein, we report a 7-year-old boy with moyamoya disease who had de novo CMBs during treatment. He presented with transient left-side motor weakness and was diagnosed with moyamoya disease. He underwent revascularization surgery on the right cerebral hemisphere. Six months after the surgery, he presented with transient right-side motor weakness and MRA revealed progression of stenosis in the left middle cerebral artery. After another 3 months, three de novo CMBs were identified. He underwent revascularization surgery on the left side. The symptom disappeared completely after surgery and no additional de novo CMBs were identified 1 year after surgery.

Conclusion:

This is the first report on de novo CMBs in pediatric patients. Although the significance of de novo CMBs in pediatric patients is completely unknown, attention should be paid to not only ischemic stroke but also hemorrhagic stroke. Although the short-term course is good in the current case, follow-up period is too short to assess for rebleeding and long-term follow-up is still important. Further, more cases should be collected.

Incidence and prevalence of moyamoya disease in urban China: a nationwide retrospective cohort study

BACKGROUND AND OBJECTIVE

Moyamoya disease (MMD) is an increasingly recognised cause of stroke, mainly described in East Asia. China is the largest nation in Asia, but few studies reported the epidemiology of MMD, especially at a national level. We aimed to estimate the incidence and prevalence of MMD in China.

METHODS

We performed a population-based study using data from the national databases of Urban Basic Medical Insurance between 2013 and 2016, covering approximately 0.50 billion individuals. MMD cases were identified by diagnostic code (International Classification of Diseases, 10th Revision I67.5) or related diagnostic text.

RESULTS

A total of 1987 MMD patients (mean age 44.45±14.30 years, female-to-male ratio 1.12) were identified, representing a national crude incidence of 0.59 (95% CI: 0.49 to 0.68) and a prevalence of 1.01 (95% CI: 0.81 to 1.21) per 100 000 person-years in 2016. Rates were higher in females than in males for the incidence (0.66 vs 0.52) and prevalence (1.05 vs 0.90). And the age-specific rates showed a bimodal distribution, with the highest peak in middle-aged group and the second peak in child group.

CONCLUSIONS

Our results confirm that MMD is relatively common in East Asians, but the rates in China were lower than those in other East Asian countries such as Japan and Korea. The unique epidemiological features, including a relatively weak female predominance and a shift in the highest peak of incidence from children to adults, revealed new sight into MMD. Further research is expected to explore the potential pathogenesis of MMD.

Pathophysiological Significance of Neutrophilic Transfer RNA-Derived Small RNAs in Asymptomatic Moyamoya Disease

Understanding asymptomatic moyamoya disease (aMMD), for which treatment options are currently limited, is key to the development of therapeutic strategies that will slow down the progression of this disease, as well as facilitate the discovery of therapeutic targets for symptomatic MMD. Newly found transfer RNA-derived small RNAs (tsRNAs) perform potential regulatory functions in neovascularization, which is a well-known pathological manifestation of MMD. In this study, the neutrophilic tsRNA transcriptome in aMMD was profiled using next-generation RNA sequencing in five patients and five matched healthy subjects. A negative binominal generalized log-linear regression was used to identify differentially expressed (DE)-tsRNAs in aMMD. Gene Ontology and functional pathway analyses were used to identify biological pathways involved with the targeted genes of the DE-tsRNAs. Four tsRNAs were selected and validated using quantitative reverse transcription polymerase chain reaction. In total, 186 tsRNAs were DE between the two groups. Pathophysiological events, including immune response, angiogenesis, axon guidance, and metabolism adjustment, were enriched for the DE-tsRNAs. The expression levels of the four DE-tsRNAs were consistent with those in the neutrophilic transcriptome. These aberrantly expressed tsRNAs and their targeted pathophysiological processes provide a basis for potential future interventions for aMMD.

Construction and Comprehensive Analysis of Dysregulated Long Noncoding RNA-Associated Competing Endogenous RNA Network in Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by chronic progressive stenosis or occlusion of the bilateral internal carotid artery (ICA), the anterior cerebral artery (ACA), and the middle cerebral artery (MCA). MMD is secondary to the formation of an abnormal vascular network at the base of the skull. However, the etiology and pathogenesis of MMD remain poorly understood.

METHODS

A competing endogenous RNA (ceRNA) network was constructed by analyzing sample-matched messenger RNA (mRNA), long non-coding RNA (lncRNA), and microRNA (miRNA) expression profiles from MMD patients and control samples. Then, a protein-protein interaction (PPI) network was constructed to identify crucial genes associated with MMD. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were employed with the DAVID database to investigate the underlying functions of differentially expressed mRNAs (DEmRNAs) involved in the ceRNA network. CMap was used to identify potential small drug molecules.

RESULTS

A total of 94 miRNAs, 3649 lncRNAs, and 2294 mRNAs were differentially expressed between MMD patients and control samples. A synergistic ceRNA lncRNA-miRNA-mRNA regulatory network was constructed. Core regulatory miRNAs (miR-107 and miR-423-5p) and key mRNAs (STAT5B, FOSL2, CEBPB, and CXCL16) involved in the ceRNA network were identified. GO and KEGG analyses indicated that the DEmRNAs were involved in the regulation of the immune system and inflammation in MMD. Finally, two potential small molecule drugs, CAY-10415 and indirubin, were identified by CMap as candidate drugs for treating MMD.

CONCLUSIONS

The present study used bioinformatics analysis of candidate RNAs to identify a series of clearly altered miRNAs, lncRNAs, and mRNAs involved in MMD. Furthermore, a ceRNA lncRNA-miRNA-mRNA regulatory network was constructed, which provides insights into the novel molecular pathogenesis of MMD, thus giving promising clues for clinical therapy.

Clinical and Radiological Outcomes After Revascularization of Hemorrhagic Moyamoya Disease

Objective: To evaluate clinical and radiological outcomes after revascularization of hemorrhagic moyamoya disease (MMD).

Materials and Methods: We retrospectively collected patients with hemorrhagic MMD who received revascularization from January 2011 to June 2018 at a high-volume stroke center. Rebleeding, ischemic stroke, modified Rankin Scale (mRS) and death after revascularization were used to evaluate long-term clinical outcome. Poor neurological outcome was defined as a mRS>2. The changes of original and revascularization collaterals were used to evaluate radiological outcome. The clinical and radiological outcomes between patients with different surgical revascularization were compared.

Results: A total of 312 patients (319 hemispheres) were recruited, including 133 hemispheres (41.7%) with indirect revascularization and 186 hemispheres (58.3%) with direct revascularization. In 308 hemispheres with clinical follow-up data, Postoperative rebleeding, ischemic stroke, poor neurological outcome and death occurred in 13.0% (40/308), 2.6% (8/308), 12.0% (37/308), and 6.2% (19/308) of the hemispheres, respectively. The rates of postoperative rebleeding (8.5 vs. 19.1%, P = 0.006) and poor neurological outcome (8.5 vs. 16.8%, P = 0.026) were lower in hemispheres with direct revascularization than those with indirect revascularization. However, there was no statistically significant difference in the rates of postoperative ischemic stroke (1.1 vs. 4.6%, P = 0.129) and death (4.5 vs. 8.4%, P = 0.162) between the two groups. Multivariate logistic regression analysis indicated that the risk of postoperative rebleeding was higher in those with untreated aneurysms, repetitive bleeding episodes, normal perfusion status, and indirect revascularization (P < 0.05). In 78 hemispheres with radiological follow-up data, the regression of moyamoya vessels, anterior choroidal artery (AchA), posterior communicating artery (PcomA) and aneurysms were present in 44.9, 47.4, 25.6, and 11.5% of the hemispheres, respectively. The regression of original collaterals and establishment of revascularization collaterals were more significant in hemispheres with direct revascularization than those with indirect revascularization (P < 0.05).

Conclusion: Direct revascularization may be superior to indirect revascularization for prevention of rebleeding and poor neurological outcome in adults with hemorrhagic MMD. The risk of postoperative rebleeding was higher in those with untreated aneurysms, repetitive bleeding episodes, normal perfusion status, and indirect revascularization. The regression of original collaterals and establishment of revascularization collaterals after revascularization were more significant in hemispheres with direct revascularization than those with indirect revascularization.

Cerebral Hemodynamic Changes After Revascularization in Patients With Hemorrhagic Moyamoya Disease

Objective: To explore the cerebral hemodynamic changes after revascularization in patients with hemorrhagic moyamoya disease (MMD).

Materials and Methods: We retrospectively included 57 hemorrhagic MMD patients in a high-volume stroke center from January 2016 to December 2018. All subjects were evaluated with whole-brain CT perfusion (CTP) before and after surgical revascularization. Absolute and relative CTP values in the regions of cortical middle cerebral artery territory (CMT) and deep brain area (DBA) of hemorrhagic hemispheres were measured. Differences between pre- and post-operative CTP values were assessed comprehensively. The patients were categorized into subgroups based on revascularization subtypes and postoperative CTP intervals.

Results: The relative cerebral blood volume (rCBV) in DBA and CMT significantly reduced in postoperative CTP (P < 0.05). The median and interquartile range of the proportion of rCBV decrease (rCBVc%) were 7.2% (2.3–13.2%). The rCBV reduction retained statistical significant in patients who received subtypes of revascularization, and in patients with variable intervals of follow-up (P < 0.05). There was no significant difference of rCBVc% between patients who received different revascularization and among patients with different postoperative CTP intervals (P > 0.05). The relative mean transit time (rMTT) and relative time to peak (rTTP) also showed downward trends, but without retainable statistical significance in stratified analysis. There was no significant change in relative cerebral blood flow (rCBF) (P > 0.05).

Conclusion: In patients with hemorrhagic MMD, the CBV appeared to decrease and be relatively stable in the chronic phase after revascularization, with varying degrees of MTT and TTP shortening. However, there was no significant change in CBF.

Circular RNAs and neutrophils: Key factors in tackling asymptomatic moyamoya disease

Moyamoya disease (MMD) represents a rare steno-occlusive disorder affecting the terminal ends of the internal carotid artery and promoting the development of a poor, abnormal vascular network at the brain's base. Primarily affecting East Asian countries over Western populations, MMD can be further divided into symptomatic and asymptomatic subtypes. The current knowledge of the underlying mechanisms and potential management strategies for asymptomatic cases of MMD are largely lacking and thus warrant investigation to elucidate the pathology of this rare disorder. Here, we assess research examining the expression profile of circular RNAs (circRNAs) of neutrophil transcriptome in asymptomatic MMD patients. These findings conclude that 123 differentially expressed circRNAs significantly contributed to metabolism, angiogenesis, and immune response. The hypoxia-inducing factor-1α signaling pathway was also revealed to be crucial in angiogenesis. We also evaluate current therapeutic options demonstrating the potential for MMD patients, such as EC-IC bypass and ischemic pre- and post-conditioning. These approaches combined with recent findings on the circRNA expression profile suggest a crucial role of anti-inflammatory and angiogenic-related mechanisms underlying MMD. Investigating the role of circRNAs and neutrophils in the asymptomatic MMD subtype may provide insight into its elusive pathology and direct future approaches to combat the progression of this rare disease.

Circular RNA profiling of neutrophil transcriptome provides insights into asymptomatic Moyamoya disease

Moyamoya disease (MMD) is a rare cerebrovascular disorder with higher incidences in Eastern Asian countries but the natural course remains uncertain. Circular RNAs (circRNAs) have been implicated in brain disorders, but their role in the development of MMD is unclear. Neutrophil depletion has been shown to affect stem cell migration, fate, and therapeutic outcomes. We investigated the circRNAs expression profile of neutrophil transcriptome in patients with asymptomatic MMD. Microarray based circRNAs profiling was determined between neutrophil samples from patients with asymptomatic MMD and healthy subjects. The microarray results were followingly confirmed by quantitative reverse-transcription PCR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses (KEGG) were adopted for annotation and predicting the functions of differentially expressed circRNAs. From this comparative circRNA microarray analysis of neutrophil samples from patients with asymptomatic MMD and healthy subjects, 123 circRNAs were identified differentially expressed between the two groups. Of these, 54 were upregulated and 69 were downregulated compared to controls (fold change >2.0 and P < 0.05). GO and KEGG analyses revealed that the differentially expressed circRNAs were mainly involved in immune responses, angiogenesis and metabolism in asymptomatic MMD. Besides, the hypoxia inducing factor-1α signaling pathway was found to be the critical pathway involved in the angiogenesis of disease pathogenesis. This is a pilot study on the neutrophils from the asymptomatic MMD and aberrantly expressed circRNAs in the profiling obtained by high-throughput microarray may help provide insights into MMD.