Vasculogenic and Angiogenic Pathways in Moyamoya Disease

HAPLN3 p.T34A contributes to incomplete penetrance of moyamoya disease in Chinese carrying RNF213 p.R4810K

BACKGROUND AND PURPOSE

The penetrance of the RNF213 p.R4810K, a founder mutation of moyamoya disease (MMD), is estimated to be only 1/150-1/300. However, the factors affecting its penetrance remain unclear. Therefore, our study aims to identify modifier genes associated with the incomplete penetrance of this founder mutation.

METHODS

Whole-exome sequencing (WES) was performed on 36 participants, including 22 MMD patients and 14 non-MMD controls with RNF213 p.R4810K mutation. Fisher's exact test was used to assess the presence of genetic variants that differed significantly between MMD patients and non-MMD controls. In order to exclude false-positive results, another 55 carriers were included to perform Fisher's exact test for the selected sites in the WES discovery stage. Subsequently, human brain microvascular endothelial cells were transfected with wild-type and mutant HAPLN3 for tube formation assays and western blotting to explore the impact of candidate genes on angiogenesis.

RESULTS

Analysis of variants from WES data revealed a total of 12 non-synonymous variants. Through bioinformatics analysis, the focus was on the HAPLN3 p.T34A variant with a significant p value of 0.00731 in Fisher's exact test. Validation through Sanger sequencing confirmed the presence of this variant in the WES data. In vitro experiments revealed that silencing HAPLN3 and transfecting HAPLN3 p.T34A significantly enhanced tube formation and increased the relative protein expression of vascular endothelial growth factor in endothelial cells.

CONCLUSIONS

These results suggest that HAPLN3 may function as a modifier gene of RNF213 p.R4810K, promoting the development of MMD and contributing to the incomplete penetrance of MMD founder mutations.

Bilateral STA-MCA bypass for Moyamoya angiopathy associated with severe erythrodermic psoriasis

OBJECTIVE

We report on the uncommon association between severe erythrodermic psoriasis and moyamoya angiopathy (MMA), a progressive cerebrovascular disorder characterized by steno-occlusive changes in the circle of Willis. Concomitant moyamoya and severe erythrodermic psoriasis is a rare pathology, with unknown pathogenesis. MMA with severe erythrodermic psoriasis, even in the setting of stroke, is often managed with non-curative medical intervention alone, due to concerns for surgical instability. Here we show with appropriate surgical consideration and medical management, patients can undergo curative surgical management, and remain stroke free during follow-up.

CASE REPORT

The patient, a 52-year-old female, with refractory psoriasis, presented with neurological deficits, leading to the diagnosis of bilateral moyamoya arteriopathy. Patients with these co-existing conditions have historically only been medially managed, due to concerns for surgical instability and inadequate candidacy. A comprehensive stroke workup revealed severe stenosis in the internal carotid arteries. A two-stage surgical revascularization, including right superficial temporal artery-middle cerebral artery (STA-MCA) bypass and subsequent left STA-MCA bypass, was successfully performed. Postoperatively, the patient experienced a severe psoriasis flare, requiring meticulous management to ensure post-operative surgical stability.

CONCLUSIONS

With appropriate medical and surgical management, the patient was amenable for curative surgical intervention. The successful surgical intervention, following medical optimization of psoriasis, demonstrated efficacy in preventing future cerebral ischemia events in this challenging patient.

Case Report: A rare presentation of rapidly progressive moyamoya disease refractory to unilateral surgical revascularization

Moyamoya disease (MMD) is a chronic, occlusive cerebrovasculopathy typified by progressive steno-occlusive disease of the intracranial internal carotid arteries (ICAs) and their proximal branches. Moyamoya syndrome (MMS) categorizes patients with characteristic MMD plus associated conditions. As such, the most usual presentations are those that occur with cerebral ischemia, specifically transient ischemic attack, acute ischemic stroke, and seizures. Hemorrhagic stroke, headaches, and migraines can also occur secondary to the compensatory growth of fragile collateral vessels propagated by chronic cerebral ischemia. While the pathophysiology of MMD is unknown, there remain numerous clinical associations including radiation therapy to the brain, inherited genetic syndromes, hematologic disorders, and autoimmune conditions. We describe the case of a 31-year-old woman who presented with recurrent ischemic cerebral infarcts secondary to rapidly progressive, bilateral MMD despite undergoing early unilateral surgical revascularization with direct arterial bypass. She had numerous metabolic conditions and rapidly decompensated, ultimately passing away despite intensive and aggressive interventions. The present case highlights that progression of moyamoya disease to bilateral involvement can occur very rapidly, within a mere 6 weeks, a phenomenon which has not been documented in the literature to our knowledge.

Comprehensive Profiling of Secreted Factors in the Cerebrospinal Fluid of Moyamoya Disease Patients

Moyamoya disease (MMD) is characterized by progressive occlusion of the intracranial internal carotid arteries, leading to ischemic and hemorrhagic events. Significant clinical differences exist between ischemic and hemorrhagic MMD. To understand the molecular profiles in the cerebrospinal fluid (CSF) of MMD patients, we investigated 62 secreted factors in both MMD subtypes (ischemic and hemorrhagic) and examined their relationship with preoperative perfusion status, the extent of postoperative angiographic revascularization, and functional outcomes. Intraoperative CSF was collected from 32 control and 71 MMD patients (37 ischemic and 34 hemorrhagic). Multiplex Luminex assay analysis showed that 41 molecules were significantly elevated in both MMD subtypes when compared to controls, including platelet-derived growth factor-BB (PDGF-BB), plasminogen activator inhibitor 1 (PAI-1), and intercellular adhesion molecule 1 (ICAM1) (p < 0.001). Many of these secreted proteins have not been previously reported in MMD, including interleukins (IL-2, IL-4, IL-5, IL-7, IL-8, IL-9, IL-17, IL-18, IL-22, and IL-23) and C-X-C motif chemokines (CXCL1 and CXCL9). Pathway analysis indicated that both MMD subtypes exhibited similar cellular/molecular functions and pathways, including cellular activation, migration, and inflammatory response. While neuroinflammation and dendritic cell pathways were activated in MMD patients, lipid signaling pathways involving nuclear receptors, peroxisome proliferator-activated receptor (PPAR), and liver X receptors (LXR)/retinoid X receptors (RXR) signaling were inhibited. IL-13 and IL-2 were negatively correlated with preoperative cerebral perfusion status, while 7 factors were positively correlated with the extent of postoperative revascularization. These elevated cytokines, chemokines, and growth factors in CSF may contribute to the pathogenesis of MMD and represent potential future therapeutic targets.

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.

Neuregulin 1 as a potential biomarker for disease progression in moyamoya disease: A case-control study in Chinese population

OBJECTIVE

Moyamoya disease (MMD) is a rare and progressive stenosis of cerebral arteries characterized by abnormally proliferative vasculopathy. Current studies have demonstrated that Neuregulin 1 (NRG1) plays a key role in angiogenesis-related disorders. Thus, the aim of our study is to investigate the serum NRG1 levels and their clinical correlations in MMD patients.

METHODS

In this study, thirty adult patients with MMD and age-gender matched healthy controls were enrolled from our hospital between July 2020 and April 2022. Peripheral blood samples were collected at baseline, and clinical data were obtained from the electronic medical record system. Serum NRG1 concentrations were measured by enzyme-linked immunosorbent assay. Sanger sequencing was applied to detect the RNF213 p.R4810K mutation.

RESULTS

The serum NRG1 levels were significantly higher in MMD patients compared to controls (14.48 ± 10.81 vs.7.54 ± 6.35mmol/L, p < 0.001). No statistical difference in baseline clinical characteristics was found between both groups. Correlation analyses showed that NRG1 levels were positively associated with Suzuki staging (r = 0.4137, p = 0.023) while not related to other clinical features (reduced cerebral blood flow, posterior cerebral artery involvement, bilateral or unilateral steno-occlusive changes). Furthermore, subgroup analysis revealed that MMD patients with the RNF213 p.R4810K mutation presented with significantly higher NRG1 levels than those without the mutation (9.60 ± 0.929 vs. 25.89 ± 4.338 mmol/L, p = 0.001).

CONCLUSIONS

Our study suggests that increased serum NRG1 levels may constitute a characteristic feature of MMD, indicating a potential positive correlation with disease progression and the presence of the RNF213 mutation. This positions NRG1 as a potentially crucial target for further studies aimed at comprehending the pathogenesis of MMD.

Liquid chromatography coupled to mass spectrometry metabolomic analysis of cerebrospinal fluid revealed the metabolic characteristics of moyamoya disease

Objective

Metabolomics has found extensive applications in the field of neurological diseases, significantly contributing to their diagnosis and treatment. However, there has been limited research applying metabolomics to moyamoya disease (MMD). This study aims to investigate and identify differential metabolites associated with MMD.

Methods

We employed a liquid chromatography coupled with mass spectrometry (LC-MS) approach, complemented by univariate and multivariate analyses, to discern metabolic biomarkers in cerebrospinal fluid samples. We then compared these biomarkers between MMD patients and healthy controls (Ctl).

Results

Sixteen patients diagnosed with MMD via cerebral angiography and eight healthy controls were enrolled in this study. Comparative analyses, including univariate and multivariate analyses, correlation studies, heatmaps, Volcano Plots, and KEGG pathway enrichment, were performed between MMD patients and controls. As a result, we identified 129 significant differential metabolites in the cerebrospinal fluid between MMD patients and controls. These metabolic biomarkers are associated with various pathways, with notable involvement in purine and pyrimidine metabolism.

Conclusion

Utilizing an LC-MS-based metabolomics approach holds promise for enhancing the clinical diagnosis of MMD. The identified biomarkers offer potential avenues for the development of novel diagnostic methods for MMD and offer fresh insights into the pathogenesis of the disease.

Molecular Biomarkers Affecting Moyamoya Disease

Although the pathogenetic pathway of moyamoya disease (MMD) remains unknown, studies have indicated that variations in the RING finger protein RNF 213 is the strongest susceptible gene of MMD. In addition to the polymorphism of this gene, many circulating angiogenetic factors such as growth factors, vascular progenitor cells, inflammatory and immune mediators, angiogenesis related cytokines, as well as circulating proteins promoting intimal hyperplasia, excessive collateral formation, smooth muscle migration and atypical migration may also play critical roles in producing this disease. Identification of these circulating molecules biomarkers may be used for the early detection of this disease. In this chapter, how the hypothesized pathophysiology of these factors affect MMD and the interactive modulation between them are summarized.

Association of thyroid peroxidase antibody with the RNF213 p.R4810K variant in ischemic stroke/transient ischemic attack

BACKGROUND AND AIMS

RNF213 is a susceptibility gene for moyamoya disease and vasospastic angina, with a second hit considered necessary for their development. Elevated thyroid peroxidase antibody (TPO-Ab) levels have been observed in both diseases, suggesting a possible role of TPO-Ab as a second hit for developing RNF213-related vasculopathy. We investigated the association of TPO-Ab levels with RNF213-related ischemic stroke (IS)/transient ischemic attack (TIA), other than moyamoya disease.

METHODS

From the National Cerebral and Cardiovascular Center Genome Registry, a multicenter, prospective, observational study, we enrolled patients with IS/TIA who were admitted within 1 week of onset. Patients with IS/TIA due to definite moyamoya disease or hemorrhagic stroke were excluded. Participants underwent genotyping for RNF213 p. R4810K, and baseline characteristics and TPO-Ab levels were compared between RNF213 p. R4810K variant carriers and non-carriers.

RESULTS

In total, 2090 IS/TIA patients were analyzed [733 women (35.1%); median age 74 (interquartile range, 63-81) years, baseline NIHSS score 3 (2-6)], and 85 (4.1%) of them carried the variant. Median TPO-Ab levels were significantly higher in variant carriers (8.5 IU/mL vs. 2.1 IU/mL, p < 0.01), who also showed a higher frequency of elevated TPO-Ab levels (>16 IU/mL) (27.1% vs. 4.4%). In the multivariate analysis, presence of the RNF213 p. R4810K variant (adjusted odds ratio, 12.42; 95% confidential interval, 6.23-24.75) was significantly associated with elevated TPO-Ab levels.

CONCLUSIONS

Elevated TPO-Ab levels may be significantly associated with presence of the RNF213 p. R4810K variant in IS/TIA patients. Thus, TPO-Ab may inherently modify IS/TIA development in RNF213 p. R4810K variant carriers.

Angiogenic and inflammatory responses in human induced microglia-like (iMG) cells from patients with Moyamoya disease

Angiogenic factors associated with Moyamoya disease (MMD) are overexpressed in M2 polarized microglia in ischemic stroke, suggesting that microglia may be involved in the pathophysiology of MMD; however, existing approaches are not applicable to explore this hypothesis. Herein we applied blood induced microglial-like (iMG) cells. We recruited 25 adult patients with MMD and 24 healthy volunteers. Patients with MMD were subdivided into progressive (N = 7) or stable (N = 18) group whether novel symptoms or radiographic advancement of Suzuki stage within 1 year was observed or not. We produced 3 types of iMG cells; resting, M1-, and M2-induced cells from monocytes, then RNA sequencing followed by GO and KEGG pathway enrichment analysis and qPCR assay were performed. RNA sequencing of M2-induced iMG cells revealed that 600 genes were significantly upregulated (338) or downregulated (262) in patients with MMD. Inflammation and immune-related factors and angiogenesis-related factors were specifically associated with MMD in GO analysis. qPCR for MMP9, VEGFA, and TGFB1 expression validated these findings. This study is the first to demonstrate that M2 microglia may be involved in the angiogenic process of MMD. The iMG technique provides a promising approach to explore the bioactivity of microglia in cerebrovascular diseases.

Physiological and pathophysiological mechanisms of the molecular and cellular biology of angiogenesis and inflammation in moyamoya angiopathy and related vascular diseases

Rationale

The etiology and pathophysiological mechanisms of moyamoya angiopathy (MMA) remain largely unknown. MMA is a progressive, occlusive cerebrovascular disorder characterized by recurrent ischemic and hemorrhagic strokes; with compensatory formation of an abnormal network of perforating blood vessels that creates a collateral circulation; and by aberrant angiogenesis at the base of the brain. Imbalance of angiogenic and vasculogenic mechanisms has been proposed as a potential cause of MMA. Moyamoya vessels suggest that aberrant angiogenic, arteriogenic, and vasculogenic processes may be involved in the pathophysiology of MMA. Circulating endothelial progenitor cells have been hypothesized to contribute to vascular remodeling in MMA. MMA is associated with increased expression of angiogenic factors and proinflammatory molecules. Systemic inflammation may be related to MMA pathogenesis.

Objective

This literature review describes the molecular mechanisms associated with cerebrovascular dysfunction, aberrant angiogenesis, and inflammation in MMA and related cerebrovascular diseases along with treatment strategies and future research perspectives.

Methods and results

References were identified through a systematic computerized search of the medical literature from January 1, 1983, through July 29, 2022, using the PubMed, EMBASE, BIOSIS Previews, CNKI, ISI web of science, and Medline databases and various combinations of the keywords "moyamoya," "angiogenesis," "anastomotic network," "molecular mechanism," "physiology," "pathophysiology," "pathogenesis," "biomarker," "genetics," "signaling pathway," "blood-brain barrier," "endothelial progenitor cells," "endothelial function," "inflammation," "intracranial hemorrhage," and "stroke." Relevant articles and supplemental basic science articles almost exclusively published in English were included. Review of the reference lists of relevant publications for additional sources resulted in 350 publications which met the study inclusion criteria. Detection of growth factors, chemokines, and cytokines in MMA patients suggests the hypothesis of aberrant angiogenesis being involved in MMA pathogenesis. It remains to be ascertained whether these findings are consequences of MMA or are etiological factors of MMA.

Conclusions

MMA is a heterogeneous disorder, comprising various genotypes and phenotypes, with a complex pathophysiology. Additional research may advance our understanding of the pathophysiology involved in aberrant angiogenesis, arterial stenosis, and the formation of moyamoya collaterals and anastomotic networks. Future research will benefit from researching molecular pathophysiologic mechanisms and the correlation of clinical and basic research results.

European Stroke Organisation (ESO) Guidelines on Moyamoya angiopathy: Endorsed by Vascular European Reference Network (VASCERN)

The European Stroke Organisation (ESO) guidelines on Moyamoya Angiopathy (MMA), developed according to ESO standard operating procedure and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, were compiled to assist clinicians in managing patients with MMA in their decision making. A working group involving neurologists, neurosurgeons, a geneticist and methodologists identified nine relevant clinical questions, performed systematic literature reviews and, whenever possible, meta-analyses. Quality assessment of the available evidence was made with specific recommendations. In the absence of sufficient evidence to provide recommendations, Expert Consensus Statements were formulated. Based on low quality evidence from one RCT, we recommend direct bypass surgery in adult patients with haemorrhagic presentation. For ischaemic adult patients and children, we suggest revascularization surgery using direct or combined technique rather than indirect, in the presence of haemodynamic impairment and with an interval of 6–12 weeks between the last cerebrovascular event and surgery. In the absence of robust trial, an Expert Consensus was reached recommending long-term antiplatelet therapy in non-haemorrhagic MMA, as it may reduce risk of embolic stroke. We also agreed on the utility of performing pre- and post- operative haemodynamic and posterior cerebral artery assessment. There were insufficient data to recommend systematic variant screening of RNF213 p.R4810K. Additionally, we suggest that long-term MMA neuroimaging follow up may guide therapeutic decision making by assessing the disease progression. We believe that this guideline, which is the first comprehensive European guideline on MMA management using GRADE methods will assist clinicians to choose the most effective management strategy for MMA.

Increase of Circulating Endothelial Progenitor Cells and Released Angiogenic Factors in Children with Moyamoya Arteriopathy

Moyamoya arteriopathy (MMA) is a rare cerebrovascular disorder that causes recurrent ischemic and hemorrhagic strokes, leading young patients to severe neurological deficits. The pathogenesis of MMA is still unknown. The disease onset in a wide number of pediatric cases raises the question of the role of genetic factors in the disease's pathogenesis. In these patients, MMA's clinical course, or progression, is largely unclear. By performing a comprehensive molecular and cellular profile in the plasma and CSF, respectively, of MMA pediatric patients, our study is aimed at assessing the levels of circulating endothelial progenitor cells (cEPC) and the release of selected proteins at an early disease stage to clarify MMA pathogenesis and progression. We employed cytofluorimetric methods and immunoassays in pediatric MMA patients and matched control subjects by age and sex. We detected increased levels of cEPC in peripheral blood and an upregulation of angiogenic markers in CSF (i.e., angiopoietin-2 and VEGF-A). This finding is probably associated with deregulated angiogenesis, as stated by the moderate severity of collateral vessel network development (Suzuki III-IV). The absence of significant modulation of neurofilament light in CSF led us to rule out the presence of substantial neuronal injury in MMA children. Despite the limited cohort of pediatric patients, we found some peculiar cellular and molecular characteristics in their blood and CSF samples. Our findings may be confirmed by wider and perspective studies to identify predictive or prognostic circulating biomarkers and potential therapeutic targets for personalized care of MMA pediatric patients.

RNF213 Loss-of-Function Promotes Angiogenesis of Cerebral Microvascular Endothelial Cells in a Cellular State Dependent Manner

Enhanced and aberrant angiogenesis is one of the main features of Moyamoya disease (MMD) pathogenesis. The ring finger protein 213 (RNF213) and the variant p.R4810K have been linked with higher risks of MMD and intracranial arterial occlusion development in east Asian populations. The role of RNF213 in diverse aspects of the angiogenic process, such as proliferation, migration and capillary-like formation, is well-known but has been difficult to model in vitro. To evaluate the effect of the RNF213 MMD-associated gene on the angiogenic activity, we have generated RNF213 knockout in human cerebral microvascular endothelial cells (hCMEC/D3-RNF213^-/-) using the CRISPR-Cas9 system. Matrigel-based assay and a tri-dimensional (3D) vascularized model using the self-assembly approach of tissue engineering were used to assess the formation of capillary-like structures. Quite interestingly, this innovative in vitro model of MMD recapitulated, for the first time, disease-associated pathophysiological features such as significant increase in angiogenesis in confluent endothelial cells devoid of RNF213 expression. These cells, grown to confluence, also showed a pro-angiogenic signature, i.e., increased secretion of soluble pro-angiogenic factors, that could be eventually used as biomarkers. Interestingly, we demonstrated that that these MMD-associated phenotypes are dependent of the cellular state, as only noted in confluent cells and not in proliferative RNF213-deficient cells.

Blood Vessels as a Key Mediator for Ethanol Toxicity: Implication for Neuronal Damage

Excessive intake of ethanol is associated with severe brain dysfunction, and the subsequent neurological and behavioral abnormalities are well-established social risks. Many research studies have addressed how ethanol induces neurological toxicity. However, the underlying mechanisms with which ethanol induces neurological toxicity are still obscure, perhaps due to the variety and complexity of these mechanisms. Epithelial cells are in direct contact with blood and can thus mediate ethanol neurotoxicity. Ethanol activates the endothelial cells of blood vessels, as well as lymphatic vessels, in a concentration-dependent manner. Among various signaling mediators, nitric oxide plays important roles in response to ethanol. Endothelial and inducible nitric oxide synthases (eNOS and iNOS) are upregulated and activated by ethanol and enhance neuroinflammation. On the other hand, angiogenesis and blood vessel remodeling are both affected by ethanol intake, altering blood supply and releasing angiocrine factors to regulate neuronal functions. Thus, ethanol directly acts on endothelial cells, yet the molecular target(s) on endothelial cells remain unknown. Previous studies on neurons and glial cells have validated the potential contribution of membrane lipids and some specific proteins as ethanol targets, which may also be the case in endothelial cells. Future studies, based on current knowledge, will allow for a greater understanding of the contribution and underlying mechanisms of endothelial cells in ethanol-induced neurological toxicity, protecting neurological health against ethanol toxicity.

Three Cases of Familial Moyamoya Disease with RASA1 Mutations-A Case Report

OBJECTIVE

The prevalence of moyamoya disease (MMD) is relatively high in East Asia, whereas the susceptibility genes of MMD have not been identified.

METHODS

Here, we reported 3 patients diagnosed with MMD from 1 single family, including a 53-year-old mother (case 1) and her 32-year-old and 29-year-old daughters (cases 2 and 3). The younger daughter was diagnosed with cerebral hemorrhage. Computed tomographic angiogram showed the typical signs of MMD in 3 patients.

RESULTS

Clinical whole-exome sequencing was performed in 3 daughters of case 1, and RASA1 mutations in chr5: 87,376,389 and NM_002890.2: c.2012-4C > T were determined to have the strongest correlation with MMD. RASA1 mutations were verified in case 1, husband of case 1 and the descendant of case 3 by using Sanger sequencing.

CONCLUSIONS

According to the findings of literature review, this is the first study indicating the association between RASA1 mutations and MMD.

Angioarchitectural Factors Associated with Postoperative Cerebral Infarction in Ischemic Moyamoya Disease

Objective: To investigate the angioarchitectural factors associated with postoperative cerebral infarction in ischemic moyamoya disease. Methods: Data on patients who underwent surgery for ischemic MMD from 1 October 2015 to 31 October 2020, at Peking University International Hospital were collected and retrospectively analyzed. General conditions such as patient sex, age, site of surgery, preoperative manifestations such as TIA attack and old cerebral infarction, and seven angioarchitectural factors of the MMD based on DSA were selected and measured. Statistical analysis was performed by the Pearson chi-square statistic, analysis of variance (ANOVA), and multifactor logistic regression analysis. Results: Age (OR, 0.969; 95%CI, 0.939–1.000; p = 0.049), A1stenosis (OR, 5.843; 95%CI, 1.730–19.732; p = 0.004), M1stenosis (OR, 6.206; 95%CI, 2.079–18.526; p = 0.001), PCA anomalies (OR, 4.367; 95%CI, 1.452–13.129; p = 0.049), Unstable compensation (OR, 5.335; 95%CI, 1.427–19.948; p = 0.013), TIA (OR, 4.264; 95%CI, 1.844–9.863; p = 0.001), Old cerebral infarction (OR, 2.972; 95%CI, 1.194–7.397; p = 0.019). The above seven factors can be used in the regression equation to predict the probability of postoperative cerebral infarction. The prediction accuracy is 90.2%. Conclusions: Age, TIA attack, old cerebral infarction, and five angioarchitectural factors of MMD are strongly associated with postoperative cerebral infarction. Seven factors, including age, TIA attack, old infarction, and four angioarchitectural factors, can be taken to quantify the probability of surgical cerebral infarction in MMD.

Influence of Autologous Bone Marrow Stem Cell Therapy on the Levels of Inflammatory Factors and Conexin43 of Patients with Moyamoya Disease

Moyamoya disease is a medical condition that shows the typical characteristics like continuous and chronic thickening of the walls and the contraction of the internal carotid artery; as a result, the internal diameter of the artery gets narrowed. There are six phases of the disease ranging from I to VI (moyamoya vessels completely disappear, followed by the complete blockage of the arteries). Surgery is a commonly recommended treatment for the moyamoya disease. Our research study identifies the effect of autologous bone marrow stem cell therapy (ABMSCT) on the levels of inflammatory factors and Conexin43 (Cx43) protein in patients suffering from moyamoya. In our study, we have selected 52 moyamoya patients admitted to our hospital from 30 July 2019 to 10 February 2020. The control group (CG) was treated with superficial temporal artery to a middle cerebral artery (STA-MCA) bypass + encephalo-duro-myosinangiosis (EDMS). The experimental group (Exp. Grp) was treated with ABMSC. The cerebral vascular tissue of the patients was treated with hematoxylin-eosin (HE) staining. Immunohistochemical staining was used to identify the levels of Cx43 protein. The concentrations of vascular endothelial growth factor (VEGF), inflammatory factor interleukin-6 (IL6), interleukin-1β (IL1β), tumor necrosis factor (TNFα), and anti-inflammatory factor interleukin-1β (IL1β) were determined by enzyme-linked immunosorbent assay (ELISA). We have found that after treatment of the expression of Cx43 protein, the proportions of grade IV (7.7%), grade III (311.5%), and grade II (3.8%) patients in the Exp. Grp were lower than those in the CG. The proportion of grade I patients in the Exp. Grp (77%) was higher than that in the CG (38.5%). After treatment, the inflammatory factors IL6 (0.97 ± 0.82 pg/mL), IL1β (8.33 ± 1.21 pg/mL), and TNFα (1.73 ± 0.71 pg/mL) in the Exp. Grp were lower than those in the CG. The anti-inflammatory factor IL1β (15.09 ± 4.72 pg/mL) increased in the Exp. Grp compared with the CG (11.25 ± 3.48 pg/mL) post treatment. Intracranial infection, hydrocephalus, hemiplegia, and transient neurological dysfunction in the Exp. Grp were lower than those in the CG, with statistical differences (P < 0.05). Our study suggests that the treatment of autologous bone marrow stem cells (ABMSC) was beneficial to balance the inflammatory response of disorders, reduce the damage of vascular tissue in the brain, and regulate tissue repair by co-acting with various inflammatory factors as compared to traditional surgery. We conclude that the involvement of Cx43 in the occurrence and development of moyamoya. We also have found that the risk factors of intracranial infection after ABMSCT were less as compared to those after conventional surgery.

Study on the serum level of CoQ10B in patients with Moyamoya disease and its mechanism of affecting disease progression

BACKGROUND

At present, the etiology and pathogenesis of Moyamoya disease (MMD) are not completely clear. Patients are usually diagnosed after cerebrovascular events. Therefore, it is of great clinical significance to explore the predictive factors of MMD.

OBJECTIVE

This study aimed to investigate the serum level of CoQ10B, the amount of endothelial progenitor cells (EPCs), and mitochondrial function of EPCs in MMD patients.

METHODS

Forty-one MMD patients and 20 healthy controls were recruited in this study. Patients with MMD were divided into two groups: Ischemic type (n=23) and hemorrhagic type (n=18). Blood samples were collected from the antecubital vein and analyzed by CoQ10B ELISA and flow cytometry. Measures of mitochondrial function of EPCs include oxygen consumption rate (OCR), mitochondrial membrane potential, Ca2+ concentration, adenosine triphosphatases activity and ROS level.

RESULTS

The serum CoQ10B level in MMD patients was significantly lower than that in healthy controls (p<0.001). The relative number of EPCs in MMD patients was significantly higher than that in healthy controls (p<0.001). Moreover, the OCR, mitochondrial membrane potential and ATPase activity were decreased and the Ca2+ and reactive oxygen species levels were increased in MMD patients (p<0.001).

CONCLUSIONS

Our results showed obviously decreased serum CoQ10B level and increased EPCs number in patients with MMD compared with healthy patients, and the mitochondria function of EPCs in MMD patients was abnormal.

Salvage multiple burr hole surgery in patients with Moyamoya disease: efficacy evaluation using probabilistic independent component analysis of dynamic susceptibility contrast perfusion MRI

PURPOSE

Multiple burr hole surgery is considered to be an option for achieving indirect revascularization in patients with ischemic Moyamoya disease (MMD). We aimed to investigate the efficacy of stand-alone multiple burr hole surgery for salvage revascularization in patients with MMD by assessing the hemodynamic changes via normalized time-to-peak (nTTP) analysis and independent component analysis (ICA) of preoperative and postoperative dynamic susceptibility contrast (DSC) perfusion MRI data.

METHODS

The DSC perfusion MRI data of 25 hemispheres from 21 patients with MMD, who underwent multiple burr hole surgery for salvage revascularization due to persistent or recurrent symptoms after primary revascularization with modified encephaloduroarteriosynangiosis (mEDAS), were analyzed. The nTTP, which was measured using the region of interests covering the entire surgical hemisphere, was compared between the preoperative and postoperative images. ICA was used to compare the relative arterial and venous components of the surgical hemispheres between the respective preoperative and postoperative images.

RESULTS

The median postoperative nTTP (1.80 s) was significantly shorter than the median preoperative nTTP (4.10 s) (P < 0.001). The postoperative relative arterial component of the surgical hemisphere (median: 0.04) was significantly higher than the preoperative relative arterial component (median: - 0.02, P < 0.001). In contrast, the postoperative relative venous component of the surgical hemisphere (median: - 0.05) was significantly lower than the preoperative value (median: 0.05, P < 0.001).

CONCLUSION

The improvement in cerebral perfusion parameters observed on postoperative DSC perfusion MRI demonstrated that stand-alone multiple burr hole surgery could be a favorable salvage revascularization technique after mEDAS failure in patients with ischemic MMD.

Plasma Lipid Profiling Contributes to Untangle the Complexity of Moyamoya Arteriopathy

Moyamoya arteriopathy (MA) is a rare cerebrovascular disorder characterized by ischemic/hemorrhagic strokes. The pathophysiology is unknown. A deregulation of vasculogenic/angiogenic/inflammatory pathways has been hypothesized as a possible pathophysiological mechanism. Since lipids are implicated in modulating neo-vascularization/angiogenesis and inflammation, their deregulation is potentially involved in MA. Our aim is to evaluate angiogenic/vasculogenic/inflammatory proteins and lipid profile in plasma of MA patients and control subjects (healthy donors HD or subjects with atherosclerotic cerebrovascular disease ACVD). Angiogenic and inflammatory protein levels were measured by ELISA and a complete lipidomic analysis was performed on plasma by mass spectrometry. ELISA showed a significant decrease for MMP-9 released in plasma of MA. The untargeted lipidomic analysis showed a cumulative depletion of lipid asset in plasma of MA as compared to HD. Specifically, a decrease in membrane complex glycosphingolipids peripherally circulating in MA plasma with respect to HD was observed, likely suggestive of cerebral cellular recruitment. The quantitative targeted approach demonstrated an increase in free sphingoid bases, likely associated with a deregulated angiogenesis. Our findings indicate that lipid signature could play a central role in MA and that a detailed biomarker profile may contribute to untangle the complex, and still obscure, pathogenesis of MA.

Platelet-to-Lymphocyte Ratio and Neutrophil-to-Lymphocyte Ratio in Patients With Newly Diagnosed Moyamoya Disease: A Cross-Sectional Study

Inflammation has been proven to be one of the key factors in the pathogenesis of moyamoya disease (MMD). Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) are cheap and reliable biomarkers of inflammation. Nevertheless, evidence regarding the relationship among PLR and NLR in patients with MMD is limited. The focus of this subject was to explore the relationship between PLR and NLR in patients with newly diagnosed MMD.

Patients and methods: A cross-sectional study was performed including 261 patients with diagnosed MMD for the first time who were enrolled from our hospital, from 24 March 2013 to 24 December 2018. The clinical characteristics were collected for each patient. Univariate analysis, smooth curve fitting and multivariate piecewise linear regression were showed.

Results: The mean levels or median values (interquartile range) of PLR and NLR were 146.979 ± 51.203 and 2.241 (1.589–2.984), respectively. A significant positive correlation between PLR and NLR levels (P < 0.001) was showed by the univariate analysis. Furthermore, a non-linear relationship was detected between PLR and NLR by smooth curve fitting after adjusting for potential confounders. A multivariate piecewise linear regression model revealed a significant positive correlation between PLR and NLR when the PLR level was lower than 219.82 (β 0.012, 95% CI 0.005, 0.019; P = 0.001). PLR was also significantly positively associated with NLR when PLR concentrations were >219.82 (β 0.098, 95% CI 0.069, 0.128; P < 0.001).

Conclusion: There seemed to be a positive association between PLR and NLR in patients with MMD. This may help to further explain the role of inflammation in the occurrence and progress of MMD.

LncRNA-mRNA Co-expression Profiles Relative to Vascular Remodeling in Moyamoya Patients Without RNF213 Mutation

OBJECTIVE

Moyamoya disease (MMD) is an idiopathic cerebrovascular disease with unknown etiology. Long noncoding RNA (lncRNA) and messenger RNA (mRNA) profiles in MMD remain unknown. In this current study, we aim to investigate lncRNA-mRNA co-expression pattern and their biological functions in superficial temporal artery (STA) of MMD.

METHODS

STA of 3 MMD patients without RNF213 mutation and 3 age-matched controls were obtained for transcriptomic RNA sequencing. Bioinformatics analysis was performed to investigate their molecular functions and interactions. Then, differentially expressed genes relative to vascular remodeling were further validated by quantitative real-time polymerase chain reaction and immunofluorescence. WNT5A functions were tested by tube formation assay and wound scratching assay in human microvascular endothelial cells (HMECs).

RESULTS

We detected 6235 different lncRNAs and 2065 different mRNAs from the RNA-sequencing between MMD patients and controls (P < 0.05; fold change >2.0). Gene ontology showed that altered mRNAs were enriched for endothelial cell morphogenesis and positive regulation of angiogenesis, which were closely related with vascular remodeling. We then searched 76 altered genes related with vascular remodeling and applied Kyoto Encyclopedia of Genes and Genomes analysis. Integrated analysis of lncRNA-TF-mRNA co-expression networks and gene verifications indicated that molecular including WNT5A, TEK, and GATA2 may contribute to the vascular malformation of MMD. Overexpression of WNT5A in HMECs promoted tube formation and cell migration.

CONCLUSIONS

In MMD patients, genes related to vascular remodeling including WNT5A and their regulators were aberrantly disrupted. These results will help elucidate the complicated pathogenic mechanism of MMD and develop potential therapeutic targets facilitating MMD angiogenesis in the future.

Evaluation and treatment of headache associated with moyamoya disease - a narrative review

BACKGROUND

Headache in patients with moyamoya disease is an under-addressed topic in the medical literature. Delay in the diagnosis of moyamoya disease or inappropriate treatment of headache could lead to devastating cerebrovascular outcome. With the evolving understanding of moyamoya disease, migraine pathophysiology, and various migraine-specific medications that have become available, it is crucial to provide an updated overview on this topic.

METHODS

We searched PubMed for keywords including moyamoya disease, moyamoya syndrome, headache in moyamoya, surgical revascularization, surgical bypass, migraine and moyamoya, and calcitonin gene-related peptide (CGRP). We summarized the literature and provide a comprehensive review of the headache presentation, possible mechanisms, the impact of various surgical revascularizations on headache in patients with moyamoya disease, and the medical management of headache incorporating novel migraine-specific treatments.Results and conclusion: The most common headache phenotype is migraine; tension-type headache, hemiplegic migraine, and cluster headache have also been reported. Most patients experience improvement of headache after surgical revascularization, though some patients report worsening, or new-onset headache after surgery. Given the complexity of moyamoya disease, careful consideration of different types of medical therapy for headache is necessary to improve the quality of life while not increasing the risk of adverse cerebrovascular events. More prospective studies are warranted to better understand and manage headache in patients with moyamoya disease.

The Genetic Basis of Moyamoya Disease

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive spontaneous bilateral occlusion of the intracranial internal cerebral arteries (ICA) and their major branches with compensatory capillary collaterals resembling a “puff of smoke” (Japanese: Moyamoya) on cerebral angiography. These pathological alterations of the vessels are called Moyamoya arteriopathy or vasculopathy and a further distinction is made between primary and secondary MMD. Clinical presentation depends on age and population, with hemorrhage and ischemic infarcts in particular leading to severe neurological dysfunction or even death. Although the diagnostic suspicion can be posed by MRA or CTA, cerebral angiography is mandatory for diagnostic confirmation. Since no therapy to limit the stenotic lesions or the development of a collateral network is available, the only treatment established so far is surgical revascularization. The pathophysiology still remains unknown. Due to the early age of onset, familial cases and the variable incidence rate between different ethnic groups, the focus was put on genetic aspects early on. Several genetic risk loci as well as individual risk genes have been reported; however, few of them could be replicated in independent series. Linkage studies revealed linkage to the 17q25 locus. Multiple studies on the association of SNPs and MMD have been conducted, mainly focussing on the endothelium, smooth muscle cells, cytokines and growth factors. A variant of the RNF213 gene was shown to be strongly associated with MMD with a founder effect in the East Asian population. Although it is unknown how mutations in the RNF213 gene, encoding for a ubiquitously expressed 591 kDa cytosolic protein, lead to clinical features of MMD, RNF213 has been confirmed as a susceptibility gene in several studies with a gene dosage-dependent clinical phenotype, allowing preventive screening and possibly the  development of new therapeutic approaches. This review focuses on the genetic basis of primary MMD only.

Clinical Management of Moyamoya Patients

Moyamoya angiopathy (MMA) is a peculiar cerebrovascular condition characterized by progressive steno-occlusion of the terminal part of the internal carotid arteries (ICAs) and their proximal branches, associated with the development of a network of fragile collateral vessels at the base of the brain. The diagnosis is essentially made by radiological angiographic techniques. MMA is often idiopathic (moyamoya disease-MMD); conversely, it can be associated with acquired or hereditary conditions (moyamoya Syndrome-MMS); however, the pathophysiology underlying either MMD or MMS has not been fully elucidated to date, and this poor knowledge reflects uncertainties and heterogeneity in patient management. MMD and MMS also have similar clinical expressions, including, above all, ischemic and hemorrhagic strokes, then headaches, seizures, cognitive impairment, and movement disorders. The available treatment strategies are currently shared between idiopathic MMD and MMS, including pharmacological and surgical stroke prevention treatments and symptomatic drugs. No pharmacological treatment able to reverse the progressive disappearance of the ICAs has been found to date in both idiopathic and syndromic cases. Antithrombotic agents are usually prescribed in ischemic MMA, although the coexisting hemorrhagic risk should be considered. Surgical revascularization techniques, which are currently the best available treatment in symptomatic MMA, are associated with good long-term outcomes and reduced ischemic and hemorrhagic risks. Given the lack of dedicated randomized clinical trials, current treatment is mainly based on observational studies and physicians’ and surgeons’ expertise.

Endothelial Progenitor Cells in Moyamoya Disease: Current Situation and Controversial Issues

Due to the lack of animal models and difficulty in obtaining specimens, the study of pathogenesis of moyamoya disease (MMD) almost stagnated. In recent years, endothelial progenitor cells (EPCs) have attracted more and more attention in vascular diseases due to their important role in neovascularization. With the aid of paradigms and methods in cardiovascular diseases research, people began to explore the role of EPCs in the processing of MMD. In the past decade, studies have shown that abnormalities in cell amounts and functions of EPCs were closely related to the vascular pathological changes in MMD. However, the lack of consistent criteria, such as isolation, cultivation, and identification standards, is also blocking the way forward. The goal of this review is to provide an overview of the current situation and controversial issues relevant to studies about EPCs in the pathogenesis and etiology of MMD.

Characteristics of Moyamoya Disease in the Older Population: Is It Possible to Define a Typical Presentation and Optimal Therapeutical Management?

Whereas several studies have been so far presented about the surgical outcomes in terms of mortality and perioperative complications for elderly patients submitted to neurosurgical treatments, the management of elderly moyamoya patients is unclear. This review aims to explore the available data about the clinical manifestation, characteristics, and outcome after surgery of older patients with moyamoya arteriopathy (MA). We found only two articles strictly concerning elderly patients with MA. We have also evaluated other reported adult series of moyamoya patients, including elderly cases in their analysis. Patients with MA above 50 years old may be considered a peculiar subset in which patients are often presenting with ischemic symptoms and a higher Suzuki grade. Conservative treatment may be proposed in asymptomatic or stable cases due to their fragility and possible increase of post-operative complications, while the best surgical options in symptomatic cases are still under investigation, although we believe that a minimal invasive superficial temporal artery—middle cerebral artery bypass could be considered the treatment of choice for the immediate effect on brain perfusion with a limited rate of post-operative complications.

Genetic and Proteomic Contributions to the Pathophysiology of Moyamoya Angiopathy and Related Vascular Diseases

RATIONALE

This literature review describes the pathophysiological mechanisms of the current classes of proteins, cells, genes, and signaling pathways relevant to moyamoya angiopathy (MA), along with future research directions and implementation of current knowledge in clinical practice.

OBJECTIVE

This article is intended for physicians diagnosing, treating, and researching MA.

METHODS AND RESULTS

References were identified using a PubMed/Medline systematic computerized search of the medical literature from January 1, 1957, through August 4, 2020, conducted by the authors, using the key words and various combinations of the key words "moyamoya disease," "moyamoya syndrome," "biomarker," "proteome," "genetics," "stroke," "angiogenesis," "cerebral arteriopathy," "pathophysiology," and "etiology." Relevant articles and supplemental basic science articles published in English were included. Intimal hyperplasia, medial thinning, irregular elastic lamina, and creation of moyamoya vessels are the end pathologies of many distinct molecular and genetic processes. Currently, 8 primary classes of proteins are implicated in the pathophysiology of MA: gene-mutation products, enzymes, growth factors, transcription factors, adhesion molecules, inflammatory/coagulation peptides, immune-related factors, and novel biomarker candidate proteins. We anticipate that this article will need to be updated in 5 years.

CONCLUSION

It is increasingly apparent that MA encompasses a variety of distinct pathophysiologic conditions. Continued research into biomarkers, genetics, and signaling pathways associated with MA will improve and refine our understanding of moyamoya's complex pathophysiology. Future efforts will benefit from multicenter studies, family-based analyses, comparative trials, and close collaboration between the clinical setting and laboratory research.

iTRAQ-based Quantitative Proteomic Analysis of Dural Tissues Reveals Upregulated Haptoglobin to be a Potential Biomarker of Moyamoya Disease

Background:

Moyamoya Disease (MMD) is a rare cerebrovascular disease with a high rate of disability and mortality. Immune reactions have been implicated in the pathogenesis of MMD, however, the underlying mechanism is still unclear.

Objective:

To identify proteins related to MMD specially involved in the immunogenesis, we performed a proteomic study.

Methods:

In this work, dural tissues or plasma from 98 patients with MMD, 17 disease controls without MMD, and 12 healthy donors were included. Proteomic profiles of dural tissues from 4 MMD and 4 disease controls were analyzed by an isobaric tag for relative and absolute quantitation (iTRAQ)- based proteomics. The immune-related proteins were explored by bioinformatics and the key MMDrelated proteins were verified by western blot, multiple reaction monitoring methods, enzyme-linked immunosorbent assay, and tissue microarray.

Results:

1,120 proteins were identified, and 82 MMD-related proteins were found with more than 1.5 fold difference compared with those in the control samples. Gene Ontology analysis showed that 29 proteins were immune-related. In particular, Haptoglobin (HP) was up-regulated in dural tissue and plasma of MMD samples compared to the controls, and its up-regulation was found to be sex- and MMD Suzuki grade dependent. Through Receiver Operating Characteristic (ROC) analysis, HP can well discriminate MMD and healthy donors with the Area Under the Curve (AUC) of 0.953.

Conclusion:

We identified the biggest protein database of the dura mater. 29 out of 82 differentially expressed proteins in MMD are involved in the immune process. Of which, HP was up-regulated in dural tissue and plasma of MMD, with sex- and MMD Suzuki grade-dependence. HP might be a potential biomarker of MMD.

Moyamoya: An Update and Review

This article is a clinical review of Moyamoya disease (MMD) and Moyamoya syndrome (MMS). We review the incidence, epidemiology, pathology, historical context, clinical and radiographic findings, diagnostic imaging modalities, radiographic grading systems, the effectiveness of medical, interventional, and surgical treatment, and some of the nuances of surgical treatment options. This article will help pediatricians, neurologists, neurosurgeons, and other clinical practitioners who are involved in caring for patients with this rare clinical entity. MMD is an intrinsic primary disease process that causes bilateral progressive stenosis of the anterior intracranial circulation with the involvement of the proximal portions of the intracranial internal carotid artery (ICA) extending to involve the proximal portions of the anterior cerebral artery (ACA) and middle cerebral artery (MCA); posterior circulation involvement is very rare. This causes a compensatory response where large numbers of smaller vessels such as the lenticulostriate arteries begin to enlarge and proliferate, which gives the angiographic appearance of a "Puff of Smoke", which is translated into Japanese as "Moyamoya". MMS is a secondary process that occurs in response to another underlying pathological process that causes stenosis of intracranial blood vessels, such as radiation. For example, an external source of radiation causes stenosis of the ICA with a compensatory response of smaller blood vessels, which then enlarge and proliferate in response and has the same "Puff of Smoke" appearance on the diagnostic cerebral angiogram (DCA). Histological findings include an irregular internal elastic lamina with luminal narrowing, hyperplasia of the tunica media, and intimal thickening with vacuolar degeneration in smooth muscle cells in the tunica media. Compensation for diminishing blood supply occurs through angiogenesis, which causes the proliferation and enlargement of smaller collateral blood vessels to increase blood supply to under-perfused areas of the brain. MMD is rare in the United States, with just 0.086 newly diagnosed cases per 100,000 individuals per year, which is approximately one per million new cases annually. Risk factors for MMD include Eastern Asian ancestry and predisposing conditions such as neurofibromatosis and Down's syndrome. Clinically, patients often present with stroke signs and symptoms from cerebral ischemia. The proliferation of collateral blood vessels within the basal ganglia can produce movement disorders. Catheter-based DCA is the current gold standard for obtaining a diagnosis. CT perfusion allows preoperative identification of ischemic vascular territories, which may be amenable to surgical intervention. MRI enables rapid detection of acute ischemic stroke using diffusion-weighted Imaging (DWI) and apparent diffusion coefficient (ADC) sequences to assess for any diffusion restriction. Non-contrast CT of the head is used to rule out acute hemorrhage in the presentation of a progressive neurological deficit. The treatment option for Moyamoya is generally surgical; medical treatment has failed to halt disease progression and neuro-interventional techniques such as attempted stenting of stenosed vessels have failed. Surgical options include direct and indirect cerebrovascular bypass.

Vascular Remodeling in Moyamoya Angiopathy: From Peripheral Blood Mononuclear Cells to Endothelial Cells

The pathophysiological mechanisms of Moyamoya angiopathy (MA), which is a rare cerebrovascular condition characterized by recurrent ischemic/hemorrhagic strokes, are still largely unknown. An imbalance of vasculogenic/angiogenic mechanisms has been proposed as one possible disease aspect. Circulating endothelial progenitor cells (cEPCs) have been hypothesized to contribute to vascular remodeling of MA, but it remains unclear whether they might be considered a disease effect or have a role in disease pathogenesis. The aim of the present study was to provide a morphological, phenotypical, and functional characterization of the cEPCs from MA patients to uncover their role in the disease pathophysiology. cEPCs were identified from whole blood as CD45^dimCD34⁺CD133⁺ mononuclear cells. Morphological, biochemical, and functional assays were performed to characterize cEPCs. A significant reduced level of cEPCs was found in blood samples collected from a homogeneous group of adult (mean age 46.86 ± 11.7; 86.36% females), Caucasian, non-operated MA patients with respect to healthy donors (HD; p = 0.032). Since no difference in cEPC characteristics and functionality was observed between MA patients and HD, a defective recruitment mechanism could be involved in the disease pathophysiology. Collectively, our results suggest that cEPC level more than endothelial progenitor cell (EPC) functionality seems to be a potential marker of MA. The validation of our results on a larger population and the correlation with clinical data as well as the use of more complex cellular model could help our understanding of EPC role in MA pathophysiology.

Heritable and non-heritable uncommon causes of stroke

Despite intensive investigations, about 30% of stroke cases remains of undetermined origin. After exclusion of common causes of stroke, there is a number of rare heritable and non-heritable conditions, which often remain misdiagnosed, that should be additionally considered in the diagnosis of cryptogenic stroke. The identification of these diseases requires a complex work up including detailed clinical evaluation for the detection of systemic symptoms and signs, an adequate neuroimaging assessment and a careful family history collection. The task becomes more complicated by phenotype heterogeneity since stroke could be the primary or unique manifestation of a syndrome or represent just a manifestation (sometimes minor) of a multisystem disorder. The aim of this review paper is to provide clinicians with an update on clinical and neuroradiological features and a set of practical suggestions for the diagnostic work up and management of these uncommon causes of stroke. The identification of these stroke causes is important to avoid inappropriate and expensive diagnostic tests, to establish appropriate management measures, including presymptomatic testing, genetic counseling, and, if available, therapy. Therefore, physicians should become familiar with these diseases to provide future risk assessment and family counseling.

A rare case of pediatric moyamoya disease with reversible white matter lesions in a 3-year-old Chinese girl

Moyamoya disease is a chronic cerebral vascular disease characterized by progressive occlusion of the cerebral arteries and resulting in the development of abnormal collateral circulation. We report a case of moyamoya disease in a 3-year-old Chinese girl with partly reversible white matter lesions. This case indicates that, in pediatric moyamoya disease, white matter lesions may be associated with cerebral ischemia, and they may be reversible after treatment.

Standardized MR Perfusion Scoring System for Evaluation of Sequential Perfusion Changes and Surgical Outcome of Moyamoya Disease

BACKGROUND AND PURPOSE

Simple-but-precise evaluation of cerebral perfusion is crucial for the treatment of Moyamoya disease. We aimed to develop a standardized scoring system for MR perfusion suitable for Moyamoya disease evaluation and investigate the postoperative serial changes and outcome predictors.

MATERIALS AND METHODS

From January 2013 to December 2016, patients diagnosed with Moyamoya disease and receiving indirect revascularization were recruited prospectively. Clinical data and serial imaging studies were analyzed. The TTP maps were standardized using cerebellar reference values. We developed a scoring system of standardized TTP maps: 14 points for each hemisphere with higher points indicating better perfusion.

RESULTS

In total, 24 children (4-17 years of age, 41 hemispheres) and 20 adults (18-51 years of age, 34 hemispheres) were included. The mean preoperative TTP scores were higher in children (7.34 ± 3.90) than in adults (4.88 ± 3.24). The standardized TTP maps revealed dynamic improvement with an increase in the corresponding scores at the 1-, 3-, and 6-month postoperative follow-ups; the scores stabilized after 6 months. The mean improvement in the 6-month scores of the pediatric and adult groups was 4.15 ± 3.55 and 6.03 ± 3.04, respectively. The 6-month TTP score improvements were associated with Matsushima grades. If we took score improvement as the outcome, the preoperative TTP score was the only significant predictor in multivariable analysis.

CONCLUSIONS

The standardized TTP maps and scoring system facilitated the quantification of the sequential perfusion changes during Moyamoya disease treatment. The preoperative perfusion status was the only predictor of indirect revascularization outcome.

GEN-O-MA project: an Italian network studying clinical course and pathogenic pathways of moyamoya disease-study protocol and preliminary results

BACKGROUND

GENetics of mOyaMoyA (GEN-O-MA) project is a multicenter observational study implemented in Italy aimed at creating a network of centers involved in moyamoya angiopathy (MA) care and research and at collecting a large series and bio-repository of MA patients, finally aimed at describing the disease phenotype and clinical course as well as at identifying biological or cellular markers for disease progression. The present paper resumes the most important study methodological issues and preliminary results.

METHODS

Nineteen centers are participating to the study. Patients with both bilateral and unilateral radiologically defined MA are included in the study. For each patient, detailed demographic and clinical as well as neuroimaging data are being collected. When available, biological samples (blood, DNA, CSF, middle cerebral artery samples) are being also collected for biological and cellular studies.

RESULTS

Ninety-eight patients (age of onset mean ± SD 35.5 ± 19.6 years; 68.4% females) have been collected so far. 65.3% of patients presented ischemic (50%) and haemorrhagic (15.3%) stroke. A higher female predominance concomitantly with a similar age of onset and clinical features to what was reported in previous studies on Western patients has been confirmed.

CONCLUSION

An accurate and detailed clinical and neuroimaging classification represents the best strategy to provide the characterization of the disease phenotype and clinical course. The collection of a large number of biological samples will permit the identification of biological markers and genetic factors associated with the disease susceptibility in Italy.

Microduplication of 15q13.3 and Microdeletion of 18q21.32 in a Patient with Moyamoya Syndrome

Moyamoya angiopathy (MA) is a cerebrovascular disease determining a progressive stenosis of the terminal part of the internal carotid arteries (ICAs) and their proximal branches and the compensatory development of abnormal “moyamoya” vessels. MA occurs as an isolated cerebral angiopathy (so-called moyamoya disease) or in association with various conditions (moyamoya syndromes) including several heritable conditions such as Down syndrome, neurofibromatosis type 1 and other genomic defects. Although the mechanism that links MA to these genetic syndromes is still unclear, it is believed that the involved genes may contribute to the disease susceptibility. Herein, we describe the case of a 43 years old woman with bilateral MA and peculiar facial characteristics, having a 484-kb microduplication of the chromosomal region 15q13.3 and a previously unreported 786 kb microdeletion in 18q21.32. This patient may have a newly-recognized genetic syndrome associated with MA. Although the relationship between these genetic variants and MA is unclear, our report would contribute to widening the genetic scenario of MA, in which not only genic mutation, but also genome unbalances are possible candidate susceptibility factors.

Circulating endothelial progenitor cells and endothelial cells in moyamoya disease

INTRODUCTION

There is no well-recognized biomarker for accurately predicting outcome in the presence of moyamoya disease (MMD), a progressive occlusive cerebrovascular disease of the internal carotid arteries or their branches. The aim of this study was to investigate the presence of endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) in MMD and correlate the findings with clinical features.

METHODS

Patients with MMD (n = 66) were compared with healthy controls (n = 81). Blood samples were obtained from an antecubital vein and analyzed using flow cytometry. EPCs were defined as CD31⁺ CD45^dim CD34^br CD133⁺ and CECs as CD31^br CD45^- CD34^dim CD133^- . Univariate and multivariate linear regression analyses were carried out.

RESULTS

The CEC counts were significantly higher in the patients than in the controls (p = 0.008). In multivariate analysis, EPC counts were independently associated with age of patients with MMD (p = 0.049) and CEC counts were independently negatively associated with concomitant disease such as hypertension, diabetes mellitus, and coronary heart disease (p = 0.034).

CONCLUSIONS

This is the first study to investigate the presence of CECs in the plasma of patients with MMD, and the amount of CECs was negatively correlated with concomitant disease in these patients.

Visualization and Classification of Deeply Seated Collateral Networks in Moyamoya Angiopathy with 7T MRI

BACKGROUND AND PURPOSE

Collateral networks in Moyamoya angiopathy have a complex angioarchitecture difficult to comprehend on conventional examinations. This study aimed to evaluate morphologic patterns and the delineation of deeply seated collateral networks using ultra-high-field MRA in comparison with conventional DSA.

MATERIALS AND METHODS

Fifteen white patients with Moyamoya angiopathy were investigated in this prospective trial. Sequences acquired at 7T were TOF-MRA with 0.22 × 0.22 × 0.41 mm³ resolution and MPRAGE with 0.7 × 0.7 × 0.7 mm³ resolution. Four raters evaluated the presence of deeply seated collateral networks and image quality in a consensus reading of DSA, TOF-MRA, and MPRAGE using a 5-point scale in axial source images and maximum intensity projections. Delineation of deeply seated collateral networks by different imaging modalities was compared by means of the McNemar test, whereas image quality was compared using the Wilcoxon signed-rank test.

RESULTS

The relevant deeply seated collateral networks were classified into 2 categories and 6 pathways. A total of 100 collateral networks were detected on DSA; 106, on TOF-MRA; and 73, on MPRAGE. Delineation of deeply seated collateral networks was comparable between TOF-MRA and DSA (P = .25); however, both were better than MPRAGE (P < .001).

CONCLUSIONS

This study demonstrates excellent delineation of 6 distinct deeply seated collateral network pathways in Moyamoya angiopathy in white adults using 7T TOF-MRA, comparable to DSA.

Intracranial artery to artery spontaneous revascularization in a child

INTRODUCTION

Intracranial artery-to-artery antegrade revascularization is a poorly recognized entity, more so when it involves main stem arteries. The etiology, appearance, and significance of this condition are not described in the literature.

CASE PRESENTATION

We describe a case of spontaneous revascularization of a chronically occluded middle cerebral arterial branch by collaterals from the proximal segment reconstituting distal flow, mimicking a brain arteriovenous malformation in a 9-year old boy. We discuss the nature of these channels, presumed to be related to artery to artery collaterals that are either dilated adventitial vasa vasorum, or, more likely, leptomeningeal collaterals that are hypertrophied in response to cerebral demand. We review the literature regarding intracerebral vasa vasorum and leptomeningeal collaterals including their imaging.

CONCLUSION

Recognizing the tortuous channels associated with this type of vascular abnormality as normal vessels reconsituting distal flow may prevent unnecessary and potentially dangerous treatments.

Autocrine release of angiopoietin-2 mediates cerebrovascular disintegration in Moyamoya disease

Moyamoya disease is a rare steno-occlusive cerebrovascular disorder often resulting in hemorrhagic and ischemic strokes. Although sharing the same ischemic stimulus with atherosclerotic cerebrovascular disease, Moyamoya disease is characterized by a highly instable cerebrovascular system which is prone to rupture due to pathological neovascularization. To understand the molecular mechanisms underlying this instability, angiopoietin-2 gene expression was analyzed in middle cerebral artery lesions obtained from Moyamoya disease and atherosclerotic cerebrovascular disease patients. Angiopoietin-2 was significantly up-regulated in Moyamoya vessels, while serum concentrations of soluble angiopoietins were not changed. For further evaluations, cerebral endothelial cells incubated with serum from these patients in vitro were applied. In contrast to atherosclerotic cerebrovascular disease serum, Moyamoya disease serum induced an angiopoietin-2 overexpression and secretion, accompanied by loss of endothelial integrity. These effects were absent or inverse in endothelial cells of non-brain origin suggesting brain endothelium specificity. The destabilizing effects on brain endothelial cells to Moyamoya disease serum were partially suppressed by the inhibition of angiopoietin-2. Our findings define brain endothelial cells as the potential source of vessel-destabilizing factors inducing the high plasticity state and disintegration in Moyamoya disease in an autocrine manner. We also provide new insights into Moyamoya disease pathophysiology that may be helpful for preventive treatment strategies in future.