Renal artery lesions in patients with moyamoya disease: angiographic findings

Vascular Abnormalities and Neurofibromatosis Type 1: A Paediatric Case Series

Neurofibromatosis type 1 (NF1) is a multisystemic neurocutaneous disease caused by a heterozygous mutation of the NF1 gene that encodes neurofibromin. Complications include vascular and neurologic abnormalities such as moyamoya syndrome, a cerebrovascular disorder with progressive occlusion of the large intracranial arteries, leading to ischemic events and the formation of abnormal vascular networks. Stenosis of the renal artery is another frequent complication of neurofibromatosis type 1, and it represents the most common cause of secondary hypertension in these patients. The purpose of the article is to describe the clinical manifestations of neurofibromatosis type 1 vasculopathy in 4 patients presenting with a wide range of neurologic and reno-vascular manifestations, as well as to examine current diagnostic management and follow-up, current therapeutic options, and to discuss further perspectives in terms of screening, diagnosis, and treatment.

The impact of hypertension on clinical outcomes in moyamoya disease: a multicenter, propensity score-matched analysis

BACKGROUND

Moyamoya disease (MMD) is a rare cerebrovascular disorder characterized by progressive steno-occlusive changes in the internal carotid arteries, leading to an abnormal vascular network. Hypertension is prevalent among MMD patients, raising concerns about its impact on disease outcomes. This study aims to compare the clinical characteristics and outcomes of MMD patients with and without hypertension.

METHODS

We conducted a multicenter, retrospective study involving 598 MMD patients who underwent surgical revascularization across 13 academic institutions in North America. Patients were categorized into hypertensive (n=292) and non-hypertensive (n=306) cohorts. Propensity score matching (PSM) was performed to adjust for baseline differences.

RESULTS

The mean age was higher in the hypertension group (46 years vs. 36.8 years, p < 0.001). Hypertensive patients had higher rates of diabetes mellitus (45.2% vs. 10.7%, p < 0.001) and smoking (48.8% vs. 27.1%, p < 0.001). Symptomatic stroke rates were higher in the hypertension group (16% vs. 7.1%; OR: 2.48; 95% CI: 1.39-4.40, p = 0.002) before matching. After PSM, there were no significant differences in symptomatic stroke rates (11.1% vs. 7.7%; OR: 1.5; CI: 0.64-3.47, p = 0.34), perioperative strokes (6.2% vs. 2.1%; OR 3.13; 95% CI: 0.83-11.82, p = 0.09), or good functional outcomes at discharge (93% vs. 92.3%; OR 1.1; 95% CI: 0.45-2.69, p = 0.82).

CONCLUSION

No significant differences in symptomatic stroke rates, perioperative strokes, or functional outcomes were observed between hypertensive and non-hypertensive Moyamoya patients. Appropriate management can lead to similar outcomes in both groups. Further prospective studies are required to validate these findings.

Vascular risk profile and changes of arterial hypertension after surgical revascularization in adult Moyamoya patients

Moyamoya disease (MMD) is a rare stenoocclusive cerebral vasculopathy often treated by neurosurgical revascularization using extracranial-intracranial bypasses to prevent ischemic or hemorrhagic events. Little is known about the vascular risk profile of adult MMD patients compared to the general population. We therefore analyzed 133 adult MMD patients and compared them with data from more than 22,000 patients from the German Health Update database. Patients with MMD showed an age- and sex-adjusted increased prevalence of arterial hypertension, especially in women between 30 and 44 years and in patients of both sexes between 45 and 64 years. Diabetes mellitus was diagnosed significantly more frequently in MMD patients with increasing age, whereas the vascular risk profile in terms of obesity, nicotine and alcohol consumption was similar to that of the general population. Antihypertensive medication was changed one year after surgical revascularization in 67.5% of patients with a tendency towards dose reduction in 43.2% of all patients. After revascularization, physicians need to be aware of a high likelihood of changes in arterial hypertension and should adjust all other modifiable systemic vascular risk factors to achieve the best treatment possible.

Hypertensive disorders of pregnancy in moyamoya disease: A single institution experience

OBJECTIVE

The characteristics of pregnancy and delivery in patients with moyamoya disease (MMD) remain unclear. We retrospectively investigated perinatal outcomes in patients with MMD to evaluate the risks associated to this condition.

MATERIALS AND METHODS

Clinical data of women with MMD who delivered at the University of Tokyo Hospital between 2000 and 2021 were collected. Maternal characteristics including genetic data, obstetric complications, method of delivery and anesthesia, neonatal outcomes, neurological events during pregnancy, delivery, and postpartum course, were reviewed.

RESULTS

Thirteen pregnancies with MMD were identified. The median maternal age was 30 years. The initial clinical symptoms were identified as transient ischemic attack, infarction, and headache. Eight patients had a history of bypass surgery. The median gestational age at delivery was 37 weeks. DNA samples were collected from five patients, responsible for six pregnancies. Of these six cases, five had the RNF213 c.14429G > A (p.Arg4810Lys) heterozygous variant. Of the 13 pregnancies, seven had hypertensive disorder of pregnancy (HDP). Additionally, three of five pregnancy cases with RNF213 p.Arg4810Lys heterozygous variant presented with HDP. Nine patients underwent cesarean section, and four delivered vaginally with epidural anesthesia. One case of ischemic stroke was confirmed during the postpartum period. Regarding newborns, neither Apgar scores lower than 7 nor neonatal intensive care unit admissions were reported.

CONCLUSIONS

This study suggests that the frequency of HDP is higher in patients with MMD compared to those with normal pregnancies. Strict blood pressure control should be performed in patients with MMD during pregnancy and postpartum period.

Moyamoya disease-specific extracellular vesicle-derived microRNAs in the cerebrospinal fluid revealed by comprehensive expression analysis through microRNA sequencing

PURPOSE

To examine the specific changes that occur in the expression levels of extracellular vesicle-derived microRNAs (miRNAs) in intracranial cerebrospinal fluid (CSF) in moyamoya disease.

METHODS

Patients with arteriosclerotic cerebral ischemia were used as controls to eliminate the effects of cerebral ischemia. Intracranial CSF was collected from moyamoya disease and control patients during bypass surgery. Extracellular vesicles (EVs) were extracted from the CSF. Comprehensive expression analysis of miRNAs extracted from EVs by next-generation sequencing (NGS) and validation by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed.

RESULTS

Experiments were conducted on eight cases of moyamoya disease and four control cases. In the comprehensive miRNA expression analysis, 153 miRNAs were upregulated, and 98 miRNAs were downregulated in moyamoya disease compared to the control cases (q-value < 0.05 and |log2 fold change|> 1). qRT-PCR performed on the four most variable miRNAs (hsa-miR-421, hsa-miR-361-5p, hsa-miR-320a, and hsa-miR-29b-3p) associated with vascular lesions among the differentially expressed miRNAs gave the same results as miRNA sequencing. On gene ontology (GO) analysis for the target genes, cytoplasmic stress granule was the most significant GO term.

CONCLUSIONS

This study is the first comprehensive expression analysis of EV-derived miRNAs in the CSF of moyamoya disease patients using NGS. The miRNAs identified here may be related to the etiology and pathophysiology of moyamoya disease.

The Development and Effect of Systemic Hypertension on Clinical and Radiological Outcome in Adult Moyamoya Angiopathy Following Revascularization Surgery: Experience of a Single European Institution

Patients with Moyamoya Angiopathy (MMA) display structurally altered vessels with decreased cerebral autoregulatory capacity, so aggressive lowering of systemic hypertension may aggravate ischemic symptoms, whereas uncontrolled hypertension may promote hemorrhage. This study provides an in-depth analysis of the role of hypertension in adult MMA patients including long-term analysis of clinical and radiological development. In this single-center retrospective analysis of 137 adult MMA patients with 206 surgically treated hemispheres angiographic images, clinical/operative data were reviewed and scored. Univariate Cox-regression analysis was performed to evaluate hypertension as a predictor for negative angiographic and clinical outcomes following revascularization surgery. A total of 50% of patients were being treated for hypertension prior to the first surgery. Patients with and without hypertension did not differ in terms of age, gender, diagnosis, symptom onset or disease severity (Berlin and Suzuki Grades). Although hypertension did not statistically significantly affect postoperative collaterals, moyamoya vessels or STA-MCA bypass patency, patients with hypertension showed higher rates of bypass patency and better bypass filling compared to those without hypertension. No significant differences in adverse events were found in patients with and without systemic hypertension and the presence of systemic hypertension was not found to predict negative clinical or radiological outcomes. In conclusion, the rate of systemic hypertension in MMA patients appears to be higher than the general population; however, this is not associated with an increased risk of postoperative complications or negative angiographic development following revascularization procedures. Systemic hypertension may also positively influence the rate of bypass patency and filling following revascularization procedures.

Research progress of moyamoya disease combined with renovascular hypertension

Moyamoya disease (MMD) is an idiopathic cerebrovascular disease which was first described by Suzuki and Takaku in 1969. Moyamoya disease is a non-atherosclerotic cerebrovascular structural disorder. MMD has been found all over the world, especially in Japan, Korea, and China. In recent years, many reports pointed out that the changes of vascular stenosis in patients with moyamoya disease occurred not only in intracranial vessels, but also in extracranial vessels, especially the changes of renal artery. Renovascular hypertension (RVH) is considered to be one of the important causes of hypertension in patients with moyamoya disease. The pathogenesis of moyamoya disease combined with renovascular hypertension is still unclear, and the selection of treatment has not yet reached a consensus. This article reviews the latest research progress in epidemiology, RNF213 gene, pathomorphology, clinical characteristics and treatment of moyamoya disease combined with renovascular hypertension, in order to provide reference for clinical workers.

Structural and Functional Characteristics of Cerebral Arteries as an Explanation for Clinical Syndromes Limited to the Brain

Vascular disease affects many different arterial beds throughout the body. Yet the brain is susceptible to several vascular disorders that either are not found in other parts of the body or when found are much less likely to cause clinical syndromes in other organs. This specific vulnerability of the brain may be explained by structural and functional differences between the vessels of the brain and those of vessels in other parts of the body. In this review, we focus on how cerebrovascular anatomy and physiology may make the brain and its vessels more susceptible to unique vascular pathologies. To highlight these differences, we use our knowledge of five diseases and syndromes that most commonly manifest in the intracranial vasculature. For each, we identify characteristics of the intracranial arteries that make them susceptible to these diseases, while noting areas of uncertainty requiring further research.

RNF213-Associated Vascular Disease: A Concept Unifying Various Vasculopathies

The ring finger protein 213 gene (RNF213) encodes a 590 kDa protein that is thought to be involved in angiogenesis. This gene was first recognized as a vasculopathy-susceptibility locus through genome-wide association studies undertaken in a Japanese population, demonstrating that heterozygotes for RNF213 p.Arg4810Lys (c.14429G>A, rs112735431) had a greatly increased risk of moyamoya disease. The association of RNF213 p.Arg4810Lys as a susceptibility variant of moyamoya disease was reproduced in Korean and Chinese individuals and, later, in Caucasians. Variants of the RNF213 gene have been linked to a number of vascular diseases such as moyamoya disease, intracranial major artery stenosis, pulmonary arterial hypertension, and peripheral pulmonary artery stenosis, and have also been associated with co-occurrent diseases and vascular disease in different organs. Based on the findings that we have reported to date, our paper proposes a new concept of “RNF213-associated vascular disease” to unify these conditions with the aim of capturing patients with multiple diseases but with a common genetic background. This concept will be highly desirable for clarifying all of the diseases in the RNF213-associated vascular disease category by means of global epidemiological investigations because of the possibility of such diseases appearing asymptomatically in some patients.

A Magnetic Resonance Angiography-Based Study Comparing Machine Learning and Clinical Evaluation: Screening Intracranial Regions Associated with the Hemorrhagic Stroke of Adult Moyamoya Disease

OBJECTIVES

Moyamoya disease patients with hemorrhagic stroke usually have a poor prognosis. This study aimed to determine whether hemorrhagic moyamoya disease could be distinguished from MRA images using transfer deep learning and to screen potential regions that contain rich distinguishing information from MRA images in moyamoya disease.

MATERIALS AND METHODS

A total of 116 adult patients with bilateral moyamoya diseases suffering from hemorrhagic or ischemia complications were retrospectively screened. Based on original MRA images at the level of the basal cistern, basal ganglia, and centrum semiovale, we adopted the pretrained ResNet18 to build three models for differentiating hemorrhagic moyamoya disease. Grad-CAM was applied to visualize the regions of interest.

RESULTS

For the test set, the accuracies of model differentiation in the basal cistern, basal ganglia, and centrum semiovale were 93.3%, 91.5%, and 86.4%, respectively. Visualization of the regions of interest demonstrated that the models focused on the deep and periventricular white matter and abnormal collateral vessels in hemorrhagic moyamoya disease.

CONCLUSION

A transfer learning model based on MRA images of the basal cistern and basal ganglia showed a good ability to differentiate between patients with hemorrhagic moyamoya disease and those with ischemic moyamoya disease. The deep and periventricular white matter and collateral vessels at the level of the basal cistern and basal ganglia may contain rich distinguishing information.

Moyamoya Disease Susceptibility Gene RNF213 Regulates Endothelial Barrier Function

BACKGROUND

Variants in the ring finger protein 213 (RNF213) gene are known to be associated with increased predisposition to cerebrovascular diseases development. Genomic studies have identified RNF213 as a major risk factor of Moyamoya disease in East Asian descendants. However, little is known about the RNF213 (ring finger protein 213) biological functions or its associated pathogenic mechanisms underlying Moyamoya disease.

METHODS

To investigate RNF213 loss-of-function effect in endothelial cell, stable RNF213-deficient human cerebral endothelial cells were generated using the CRISPR-Cas9 genome editing technology.

RESULTS

In vitro assays, using RNF213 knockout brain endothelial cells, showed clear morphological changes and increased blood-brain barrier permeability. Downregulation and delocalization of essential interendothelial junction proteins involved in the blood-brain barrier maintenance, such as PECAM-1 (platelet endothelial cell adhesion molecule-1), was also observed. Brain endothelial RNF213-deficient cells also showed an abnormal potential to transmigration of leukocytes and secreted high amounts of proinflammatory cytokines.

CONCLUSIONS

Taken together, these results indicate that RNF213 could be a key regulator of cerebral endothelium integrity, whose disruption could be an early pathological mechanism leading to Moyamoya disease. This study also further reinforces the importance of blood-brain barrier integrity in the development of Moyamoya disease and other RNF213-associated diseases.

The clinical and radiological cerebrovascular abnormalities associated with renovascular hypertension in children: a systematic review

Renovascular disease is an important secondary cause of hypertension in childhood. In this cohort, many may have undiagnosed cerebrovascular disease, and some children present acutely with cerebrovascular complications. However, these associations are yet to be defined in the literature.A systematic review of clinical and radiological abnormalities associated with renovascular hypertension in the global pediatric (< 18 years) population. The MEDLINE, Embase, and Google Scholar databases were searched, from database inception to 26 January 2021. Primary articles were unrestricted by study design and geographical location but were limited to those published in English.A total of 303 individuals (median age: 7.6 years [range 10 days-17.9 years]; M:F, 174:129) from 34 studies were included, across 13 countries. Twenty-seven individual cases were published for children with coexisting renovascular hypertension and cerebrovascular disease. Most children had bilateral renal artery stenosis, secondary to fibromuscular dysplasia and had coexisting occlusive cerebrovascular disease. The majority presented with neurological symptoms, and cerebral complication ranged from asymptomatic cerebrovascular stenosis to acute stroke and posterior reversible encephalopathy syndrome. The location or underlying etiology of the renovascular disease did not predict the location or extent of the cerebrovascular disease. The evidence from the cohort studies was limited, as none specifically established a cohort of children with coexisting disease. Furthermore, the conclusions drawn were subjected to considerable bias from the treating clinicians.A prospective cohort of children with renovascular hypertension and cerebrovascular complications should be established so the long-term prognosis and impact of treatment may be better understood.

Cephalic/cardiac neural crest cell and moyamoya disease

BACKGROUND

The neural crest is a transient structure present in early embryogenesis. Cephalic neural crest cells migrate into the pharyngeal arches and the frontonasal process that becomes the forehead and midfacial structures. They also contribute to forming the media of the arteries of the circle of Willis and their branches. The cardiac neural crest produces vascular smooth muscle cells in the ascending aorta, cardiac septum and coronary arteries.

METHODS

In this review, we evaluate the role of the neural crest in moyamoya disease and the pathological implications from the concurrence of moyamoya disease and cardiovascular diseases from the point of view of neural crest cell distributions.

RESULTS

Midline craniofacial and central nervous system anomalies with eye anomalies, morning glory disc anomaly in patients with moyamoya disease can both be explained as a subtype of cephalic neurocristopathy. Further, the association between moyamoya disease and cardiac manifestations (congenital cardiac defects and coronary artery disease) have also been reported. Both the cephalic neural crest and cardiac neural crest contribute to these concurrent arterial diseases, as cardio-cephalic neurocristopathy.

CONCLUSION

The concept of cephalic/cardio-cephalic neurocristopathy provides a new perspective to understanding the underlying aetiological associations and to developing future therapeutic approaches for concomitant moyamoya disease and cardiovascular diseases.

Pathophysiology of Vascular Stenosis and Remodeling in Moyamoya Disease

Moyamoya disease (MMD) and moyamoya syndrome (MMS) are progressive vascular pathologies unique to the cerebrovasculature that are important causes of stroke in both children and adults. The natural history of MMD is characterized by primary progressive stenosis of the supraclinoid internal carotid artery, followed by the formation of fragile collateral vascular networks. In MMS, stenosis and collateralization occur in patients with an associated disease or condition. The pathological features of the stenosis associated with MMD include neointimal hyperplasia, disruption of the internal elastic lamina, and medial attenuation, which ultimately lead to progressive decreases in both luminal and external arterial diameter. Several molecular pathways have been implicated in the pathophysiology of stenosis in MMD with functions in cellular proliferation and migration, extracellular matrix remodeling, apoptosis, and vascular inflammation. Importantly, several of these molecular pathways overlap with those known to contribute to diseases of systemic arterial stenosis, such as atherosclerosis and fibromuscular dysplasia (FMD). Despite these possible shared mechanisms of stenosis, the contrast of MMD with other stenotic pathologies highlights the central questions underlying its pathogenesis. These questions include why the stenosis that is associated with MMD occurs in such a specific and limited anatomic location and what process initiates this stenosis. Further investigation of these questions is critical to developing an understanding of MMD that may lead to disease-modifying medical therapies. This review may be of interest to scientists, neurosurgeons, and neurologists involved in both moyamoya research and treatment and provides a review of pathophysiologic processes relevant to diseases of arterial stenosis on a broader scale.

Microcephalic osteodysplastic primordial dwarfism type II is associated with global vascular disease

BACKGROUND

Microcephalic osteodysplastic primordial dwarfism type II (MOPDII) is the most common form of primordial dwarfism, caused by bialleic mutations in the pericentrin gene (PCNT). Aside from its classic features, there are multiple associated medical complications, including a well-documented risk of neurovascular disease. Over the past several years, it has become apparent that additional vascular issues, as well as systemic hypertension and kidney disease may also be related to MOPDII. However, the frequency and extent of the vasculopathy was unclear. To help address this question, a vascular substudy was initiated within our Primordial Dwarfism Registry.

RESULTS

Medical records from 47 individuals, living and deceased, ranging in age from 3 to 41 years of age were interrogated for this purpose. Of the total group, 64% were diagnosed with moyamoya, intracranial aneurysms, or both. In general, the age at diagnosis for moyamoya was younger than aneurysms, but the risk for neurovascular disease was throughout the shortened lifespan. In addition to neurovascular disease, renal, coronary and external carotid artery involvement are documented. 43% of the total group was diagnosed with hypertension, and 17% had myocardial infarctions. A total of 32% of the entire cohort had some form of chronic kidney disease, with 4% of the total group necessitating a kidney transplant. In addition, 38% had diabetes/insulin resistance. Ages of diagnoses, treatment modalities employed, and location of vasculopathies were notated as available and applicable, as well as frequencies of other comorbidities.

CONCLUSIONS

It is now clear that vascular disease in MOPDII is global and screening of the cardiac and renal vessels is warranted along with close monitoring of blood pressure. We recommend a blood pressure of 110/70 mmHg as a starting point for an upper limit, especially if the individual has a history of neurovascular disease, chronic kidney disease and/or diabetes. Additionally, providers need to be at high alert for the possibility of myocardial infarctions in young adults with MOPDII, so that appropriate treatment can be initiated promptly in an acute situation.

Moyamoya disease with refractory hypertension associated with peripheral arterial stenosis in the renal parenchyma

Moyamoya disease (MMD) has long been known to be associated with hypertension. While renal artery stenosis (RAS) is considered one of the causes of hypertension with MMD, most hypertension causes remain unexplained. A boy with MMD was diagnosed with renovascular hypertension (RVH) due to left-sided RAS by angiography. Although nephrectomy on the affected side for unilateral RVH was performed, hypertension poorly improved. Histopathological examination of the resected specimens revealed that the vascular lumen not only of the renal artery but also of peripheral vessels in the renal parenchyma was narrowed. He developed end-stage renal disease caused by multiple wasp stings and received a kidney transplant from a living donor with his remaining right kidney resected. His hypertension improved dramatically just after the operation. In histopathological findings, the narrowed vascular lumen was also observed in the resected right renal parenchyma similar to that in the left kidney. In our case, these pathological findings were the same as those of major vessels previously reported in MMD patients. Immunohistochemical staining with anti-renin antibody on bilateral intrinsic kidneys was strongly revealed in the Juxtaglomerular apparatus. He has been normotensive with the minimum amount of amlodipine since transplantation and resection of his intrinsic right kidney. This is the first report to show the possibility that peripheral arterial stenosis in the renal parenchyma due to MMD would result in refractory hypertension. If MMD patients have hypertension of unknown origin without significant RAS, it should be considered that the etiology may be peripheral arterial stenosis in the renal parenchyma.

Hypertension and childhood stroke

Cerebrovascular disease (stroke) is one of the ten leading causes of death in children and adolescents. Multiple etiologies, from arteriopathies to prothrombic states, can cause stroke in youth. In adult stroke, hypertension has been shown to be the single most important modifiable risk factor. Although hypertension has not been strongly identified as a risk factor in childhood stroke to date, there is preliminary evidence that suggests that hypertension may also be associated with stroke in children. In this review, we summarize the literature that may link hypertension to stroke in the young. We have identified a series of barriers and limitations in the fields of pediatric hypertension and pediatric neurology that might explain why hypertension has been overlooked in childhood stroke. We suggest that hypertension may be a relevant risk factor that, alone or in combination with other multiple factors, contributes to the development of stroke in children. Currently, there are no consensus guidelines for the management of post-stroke hypertension in children. Thus, we recommend that blood pressure be assessed carefully in every child presenting with acute stroke in order to better understand the effects of hypertension in the development and the outcome of childhood stroke. We suggest a treatment algorithm to help practitioners manage hypertension after a stroke.

Meta-analysis of genotype and phenotype studies to confirm the predictive role of the RNF213 p.R4810K variant for moyamoya disease

BACKGROUND AND PURPOSE

The aim of this meta-analysis study was to assess the predictive effects of RNF213 p.R4810K on phenotype in moyamoya disease (MMD).

METHODS

Electronic databases (e.g., Pubmed and EMBASE) were searched, and relevant articles published up to August 2020 were retrieved. Review Manager 5.3 and Stata 12.0 were used for all statistical analyses. Pooled odds ratios, with 95% confidence intervals, and three comparison models were evaluated to analyze the association between RNF213 pR4810K variant and clinical characteristics of MMD patients using a fixed-effects model.

RESULTS

A total of 2798 patients with MMD were selected and the effects of the heterozygous or homozygous RNF213 p.R4810K variant on 18 clinical features were identified. There were more patients aged <15 years in the GA and AA groups (AA vs GA: p = 0.009; AA vs GG: p = 0.003; GA vs GG: p = 0.001). Among homozygous patients, the majority experienced MMD onset before the age of 4 years (AA vs. GA: p < 0.00001; AA vs GG: p < 0.00001). The frequency of infarctions and transient ischemic attack was significantly higher in homozygotes and heterozygotes，respectively. However, the frequency of intracerebral/intraventricular hemorrhage was lower in patients with the GA than the GG genotype. More MMD patients with AA and GA genotypes had a family history of the disease (p = 0.003, p < 0.00001, respectively). Posterior cerebral artery involvement was more common in patients with the GA genotype (p < 0.00001).

CONCLUSION

The homozygous or heterozygous RNF213 variant may be an efficient biomarker with which to classify different clinical phenotypes of MMD.

Clinical characteristics of the pregnancies and deliveries of patients with moyamoya disease: A single-center analysis over three decades

BACKGROUND AND AIMS

As moyamoya disease in pregnancy is clinically rare, it is poorly understood. We therefore analyzed our experiences of moyamoya disease pregnancies and deliveries over three decades.

METHODS

The clinical data of 78 pregnancies and 77 deliveries among 62 moyamoya disease cases at Tokyo Medical and Dental University Hospital from 1991 to 2019 were retrospectively reviewed.

RESULTS

There were six, 17 and 55 pregnancies in the first, second, and last decades, respectively. The mean patient age at delivery was 29.3 ± 5.0 years. The primary symptoms of moyamoya disease at diagnosis were ischemia in 50 cases (64.1%) and intracranial hemorrhage in eight cases (10.2%). Cesarean section was performed in 75 cases (96.2%). Fifteen pregnancies (19.2%) developed hypertensive disorders of pregnancy; of these, 13 (86.7%) developed hypertensive disorders of pregnancy after 34 weeks of gestation and 9 (60%) required emergency cesarean section because of a sudden increase in blood pressure. Four (5.1%) women experienced renal artery stenosis complications and three of them developed hypertension during pregnancy. Two (2.6%) experienced cerebral infarctions several days after delivery, both of whom had no subsequent aftereffects. No cases of hemorrhagic stroke were reported in the peripartum period.

CONCLUSIONS

To date, this is the largest single-center analysis. It showed the number of moyamoya disease pregnancies has risen rapidly over the last decade. The hypertensive disorders of pregnancy and emergency cesarean section rates were high among moyamoya disease patients. Minor ischemic stroke was observed, but its prevalence was low. Therefore, pregnant women with moyamoya disease should be managed with the understanding that hypertensive disorders of pregnancy is a common complication.

Association of single nucleotide polymorphisms of MTHFR, TCN2, RNF213 with susceptibility to hypertension and blood pressure

Methylenetetrahydrofolate reductase gene (MTHFR), transcobalaminII (TCN2) and ring finger protein 213 (RNF213) are related to homocysteine (Hcy) level and are of great significance for hypertension. We aimed to evaluate the associations of MTHFR (rs1801133, rs1801131, rs9651118), TCN2 (rs117353193) and RNF213 (rs9916351) with hypertension and blood pressure (BP). A total of 953 patients with hypertension and 1103 controls were enrolled. Genotyping was performed by Taqman. Logistic regression analysis indicated that A allele of TCN2 rs117353193 under the dominant model had a significantly protective effect (P=0.045) after adjustment, which showed that AA+GA genotype has a lower risk than GG. Additionally, the average diastolic BP (DBP) (P=0.044) and mean arterial pressure (MAP) (P=0.035) levels were significantly different between genotypes of RNF213 rs9916351. Further pairwise comparison showed that the average systolic BP (SBP) level of the TT genotype carriers were significantly higher than in CC (P=0.024), and the average DBP and MAP levels of the TT genotype carriers were higher than in CT (P=0.044, P=0.012, respectively) and CC (P=0.048, P=0.010, respectively). In the recessive model, the average SBP (P=0.043), DBP (P=0.018) and MAP (P=0.017) levels with the TT genotype carriers were significantly higher than in CT+CC. Multiple linear regression analysis suggested that RNF213 rs9916351 in the recessive model had significant effects on SBP (P=0.025), DBP (P=0.017) and MAP (P=0.010) as a risk factor. However, no associations were observed between MTHFR and hypertension. TCN2 rs117353193 might serve as a protective factor in hypertension, and RNF213 rs9916351 might be a risk factor that is linked to increase BP level in Northeast Chinese population.

Prospective Screening of Extracranial Systemic Arteriopathy in Young Adults with Moyamoya Disease

Background

RNF213 is a major susceptibility gene for moyamoya disease (MMD), characterized by chronic progressive steno‐occlusion of the intracranial arteries. However, coincidental extracranial arteriopathy is sporadically described in a few cases and in children with MMD.

Methods and Results

This study prospectively enrolled 63 young adults (aged 20–49 years) without a known history of systemic vascular diseases who were confirmed to have definite (bilateral, n=54) or probable (unilateral, n=9) MMD, as per typical angiographic findings. Coronary and aorta computed tomography angiography was performed to characterize extracranial arteriopathy and investigate its correlation with clinical characteristics and MMD status, including the RNF213 p.Arg4810Lys variation (c.14429G>A, rs112735431). Altogether, 11 of 63 patients (17%) had significant (>50%) stenosis in the coronary (n=6), superior mesenteric (n=2), celiac (n=2), renal (n=1), and/or internal iliac artery (n=1). One patient showed both mesenteric and iliac artery stenosis. Patients with extracranial arteriopathy were more likely to have diabetes mellitus and posterior cerebral artery involvement. Moreover, a higher prevalence of extracranial arteriopathy was observed in the presence of the RNF213 p.Arg4810Lys variant (67% in homozygotes). After controlling for diabetes mellitus and posterior cerebral artery involvement, the p.Arg4810Lys variant was independently associated with extracranial arteriopathy (additive model; P=0.035; adjusted odds ratio, 4.57; 95% CI, 1.11–27.20).

Conclusions

Young adults with MMD may have concomitant extracranial arteriopathy in various locations. Patients with RNF213 variants, especially the p.Arg4810Lys homozygous variant, should be screened for systemic arteriopathy.

High prevalence of pro-thrombotic conditions in adult patients with moyamoya disease and moyamoya syndrome: a single center study

BACKGROUND

Moyamoya Disease (MMD) and moyamoya Syndrome (MMS) have been reported to be associated with pro-thrombotic states in some patients. To date, however, such reports have been limited to case reports or small case series. We sought to determine the prevalence of pro-thrombotic states among a large cohort of both MMD and MMS patients.

METHODS

We retrospectively reviewed the medical records of all adult patients who were diagnosed with MMD or MMS from our institution. In addition to basic demographic and clinical data, the presence of certain pro-thrombotic conditions was noted. The presence of such conditions was determined based on review of clinical diagnoses and laboratory reports. The length of follow-up and the presence of interval ischemic events were obtained.

RESULTS

Out of a total of 180 patients diagnosed with MMD or MMS, 33 were found to have a concomitant pro-thrombotic condition (18.3%). Of 147 patients with MMD, 23 were found to have a pro-thrombotic condition (15.6%). There were 10 out of 33 total patients (30.3%) in the MMS cohort that had a concomitant pro-thrombotic condition. There were no differences in specific pro-thrombotic conditions between MMD and MMS cohorts. There were no differences in future ischemic events between moyamoya patients with pro-thrombotic tendencies compared to those without (13.3% versus 23.7%, respectively, P = 0.32), and this was also true for patients who underwent revascularization procedures (22.6% versus 29.4%, P = 0.76). There was also no difference in prevalence of revascularization graft occlusion between moyamoya patients with pro-thrombotic tendencies and those without at follow-up (1.2% versus 5.9%, P = 0.31).

CONCLUSIONS

It is likely that both MMD and MMS are associated with or predispose to pro-thrombotic conditions in adult patients, although the clinical and surgical significance is uncertain. Further study is needed in order to further elucidate and characterize this potential association.

Comparison of clinical outcomes and characteristics between patients with and without hypertension in moyamoya disease

OBJECTIVE

Our study aimed to compare the disparity of patients with moyamoya disease (MMD) between hypertension group and non-hypertension group. And we attempt to explore the risk factors for MMD with hypertension.

METHODS

We retrospectively analyze 542 adult patients with moyamoya disease admitted to our hospital from 2009 to 2016. In view of inclusion criteria, we divided patients with moyamoya disease into two groups (hypertension group and non-hypertension group) and summarized their clinical characteristics. Furthermore, we explore the risk factors for unfavorable outcomes in hypertension group.

RESULTS

Of 542 adult patients with moyamoya disease, we identified 156 patients (28.8%) with hypertension and 386 patients (71.2%) without hypertension. During follow-up, we hold the views that the prognosis of non-hypertension group was obviously better than hypertension group (P = 0.005) and the complications were prone to occurring to patients with hypertension (P = 0.037). In the multivariate analysis, severe hypertension (OR, 2.746; 95% CI, 1.096-6.822; P = 0.031) and no anti-hypertensive medication (OR, 0.342; 95% CI, 0.131-1.895; P = 0.029) were the independent predictors for postoperative unfavorable outcomes. The common surgical modalities of moyamoya disease (direct and indirect bypass) had no significant difference in future unfavorable outcomes prevention in adult MMD patients with hypertension.

CONCLUSIONS

We suggested severe hypertension and no anti-hypertensive medication as the independent risk factors for unfavorable clinical outcomes in adult MMD with hypertension.

De Novo Renal Artery Stenosis Developed in Initially Normal Renal Arteries during the Long-Term Follow-Up of Patients with Moyamoya Disease

BACKGROUND

The de novo occurrence of renal artery stenosis in renal arteries that were angiographically confirmed to be normal in the past has never been reported before in patients with moyamoya disease.

CASE DESCRIPTION

During the long-term follow-up of pediatric patients with moyamoya disease, we observed 3 patients who developed de novo renal artery stenosis in arteries that had been angiographically confirmed to be normal 1 year after the surgery (7 years on average, ranging from 4 to 11 years). All of these patients were neurologically stable after successful indirect bypass surgery during childhood. However, more than 10 years after the surgery (15 years on average, ranging from 14 to 23 years), they developed hypertension and were found to have de novo renal artery stenosis, which was ameliorated by endovascular angioplasty. During the follow-up after angioplasty, 1 patient experienced a recurrence of hypertension and required a second and third angioplasty for restenosis. Another patient died of intracranial hemorrhage 2 years after angioplasty. In the 2 surviving patients, gene analysis of the ring finger protein 213 (RNF213; p.R4810K) point mutation, the susceptibility gene for moyamoya disease in the Asian population, was positive for the heterozygous variant.

CONCLUSIONS

De novo renal artery stenosis might develop in initially normal arteries during long-term follow-up, particularly among pediatric patients with moyamoya disease. Considering the extracranial manifestations of moyamoya disease, clinicians should keep in mind that de novo renal artery stenosis could emerge later in their life. Thus, it is crucial to continue to follow these patients for decades, even if the patients are neurologically stable after bypass surgery. Monitoring for blood pressure and the de novo occurrence of renal artery stenosis is important to prevent hypertension-related morbidity and mortality, such as intracranial hemorrhage, in this disease population.

High prevalence of systemic hypertension in pediatric patients with moyamoya disease years after surgical treatment

OBJECTIVE

Although an association between moyamoya disease (MMD) and renovascular hypertension has been acknowledged, the literature on systemic hypertension without renal artery stenosis among patients with MMD is scarce. The authors aimed to evaluate the prevalence and risk factors of hypertension using data from MMD patients who visited an outpatient clinic of a pediatric neurosurgical department in 2016.

METHODS

The authors evaluated the blood pressure (BP) of pediatric MMD patients at their postsurgical appointment following the American Academy of Pediatrics clinical practice guideline on high BP, in which hypertension was defined as BP measurements higher than the value of age-, sex-, and height-specific 95th percentile of the general population from at least 3 separate visits. Growth of patients was determined using 2017 Korean National Growth Charts for children and adolescents. The cutoff value of the 95th percentile of BP was determined by referring to normative BP tables of Korean children and adolescents. A logistic regression model was used to assess the associations between patients' clinical characteristics and prevalent hypertension.

RESULTS

In total, 131 surgically treated pediatric MMD patients were included, of whom 38.9% were male and the median age at diagnosis was 8.0 years (range 1.2-15.0 years). The definition of hypertension was met in 38 patients, with a prevalence of 29.0% (95% CI 21.2%-36.8%). A tendency was observed for a higher prevalence of hypertension in male patients (31.4%), in patients with posterior cerebral artery (PCA) involvement (47.8%), and in cases in which infarction was shown on initial MRI (37.3%). Age at diagnosis (adjusted OR [aOR] 0.82, 95% CI 0.70-0.97), PCA involvement (aOR 3.81, 95% CI 1.29-11.23), body mass index (aOR 1.30, 95% CI 1.13-1.51), and years of follow-up since surgery (aOR 0.80, 95% CI 0.68-0.94) were related to systemic hypertension.

CONCLUSIONS

A high prevalence of hypertension was demonstrated in pediatric MMD patients. Therefore, adequate attention should be paid to reduce BP and prevent subsequent events.

[Coronary artery spasm revealed by an out-of-hospital cardiac arrest associated with a moyamoya disease. A case report of multimodality imaging]

Moyamoya disease is a rare angiopathy characterized by a progressive distal occlusion of the internal carotid arteries and their branches. Extracerebral involvement, including coronary arteries, has been described. We report the case of a patient with moyamoya disease who suffered an out-of-hospital cardiac arrest associated with coronary spasm. We discussed the possible links between coronary spasm and moyamoya, as well as the contribution of multimodal cardiac imaging, combining conventional and intracoronary imaging, cardiac MRI, provocative tests for spasm, in the exploration of out-of-hospital cardiac arrest without obvious electrocardiographic and angiographic cause.

Late Cerebrovascular Events and Social Outcome after Adolescence: Long-term Outcome of Pediatric Moyamoya Disease

In this article, the authors review the literature related to long-term outcome of pediatric moyamoya disease, focusing on late cerebrovascular events and social outcome of pediatric patients once they reach adulthood. Late-onset de novo hemorrhage is rare but more serious than recurrence of ischemic stroke. Long-term follow-up data on Asian populations suggest that the incidence of de novo hemorrhage might increase at age 20 or later, even more than 10 years after bypass surgery. Social adaptation difficulty, possibly related to cognitive impairment caused by frontal ischemia, continues in 10-20% of patients after they reach adulthood, even if no significant disability is present in daily life. A treatment strategy aimed at improving long-term outcome and careful follow-up might be required.

Low frequency of cervicocranial artery involvement in Japanese with renal artery fibromuscular dysplasia compared with that of Caucasians

BACKGROUND

Fibromuscular dysplasia (FMD), which usually affects the renal artery, also affects the carotid, vertebral, and intracranial arteries. Previous studies have shown a high prevalence of concomitant renal artery and cervicocranial lesions in FMD patients. However, the analyzed subjects were mostly Caucasians in Western countries.

METHOD

We performed a retrospective analysis to examine the prevalence of cervicocranial vascular lesions in Japanese FMD patients with renal artery involvement at a single institution. The presence of cervicocranial lesions was evaluated by Doppler echography and magnetic resonance angiography. We compared this prevalence with that reported in the literature.

RESULT

Thirty-one Japanese FMD patients with renal artery lesions were studied. The mean age was 30 ± 12 years, 71% were women, and 16% were smokers; all patients were Asians and had hypertension. Multifocal, tubular, and unifocal types of renal lesions were found in 52, 35, and 13% of patients, respectively. Bilateral renal lesions were found in 13% of patients. None of the patients had a cervical vascular lesion associated with FMD. Only two patients (8%) had a lesion in the intracranial artery, of which one was a known case of moyamoya disease.

CONCLUSION

These findings suggest that cervical artery involvement and intracranial artery involvement are not common in renal FMD patients in Japan, which is in contrast to the data reported for Caucasian patients in Western countries. Ethnic differences could influence the occurrence of cervicocranial lesions. A study with a larger sample size should be performed to validate these findings.

Moya-Moya syndrome after cranial radiation for optic glioma with NF1. Case report and literature review of syndromic cases

INTRODUCTION

Moya-Moya angiopathy is a neurovascular disease that predisposes to ischemic or hemorrhagic strokes. It is generated by a steno-occlusion of the terminal portion of the internal carotid arteries, which induces the development of abnormal neovessels in the deep regions of the brain. Some pathologies such as sickle cell disease, Down syndrome or Graves' disease may be associated with Moya-Moya angiopathy. These syndromic forms harbor several differences compared with idiopathic Moya-Moya disease.

CASE REPORT

We report the case of a young patient who presented with a syndromic form of Moya-Moya angiopathy after cranial radiation therapy for an optic glioma associated with type 1 neurofibromatosis treated by combined revascularization. We discuss the particularities of syndromic forms, in their presentation and management based on a review of the literature.

CONCLUSION

Many diseases can be associated with Moya-Moya syndrome. Symptomatic patients should undergo surgery, but the risk of postoperative complications appears to be greater than that encountered in patients with non-syndromic Moya-Moya angiopathy.

Novel and recurrent RNF213 variants in Japanese pediatric patients with moyamoya disease

Moyamoya disease is a progressive steno-occlusive condition of the main intracranial arteries that results in the compensatory formation of fragile moyamoya vessels at the base of the brain. RNF213 is the most significant susceptibility gene and is often found with the p.Arg4810Lys founder variant in East Asian patients. We identified three putatively deleterious variants of this gene from three pediatric patients: two were novel, and one was a recurrent missense variant previously reported in other pediatric patients.

Long-Term Outcomes of Pediatric Renovascular Hypertension

BACKGROUND/AIMS

Renovascular hypertension (RVHT) is an important cause of childhood hypertension. This study evaluated the clinical characteristics and outcomes of Korean children with RVHT.

METHODS

Children treated for RVHT between 2000 and 2015 at our center were retrospectively reviewed.

RESULTS

Forty-six children were followed for a median of 6.5 (0.66-27.23) years. Forty-five percutaneous transluminal angioplasties (PTAs) were performed in 32 children. At the last visit, clinical benefit was observed in 53.3% of children. Patients with comorbid cerebrovascular disease (CVD) showed less favorable long-term outcomes after PTA (clinical benefit in 41.7% vs. 61.1% in others) and higher restenosis rates (50% vs. 31.6% in others). Surgical procedures (bypass or nephrectomy) were performed in 8 patients. After surgery, blood pressure was normalized in 2 patients, improved in 3 patients, and unchanged in the remaining patients. Between PTA group (n=21) and medication group (n=14), percentage of atrophic kidneys became higher after follow-up period in medication group than in PTA group (60.0% vs. 26.1%, P=0.037).

CONCLUSION

Aggressive treatment of pediatric RVHT yielded fair outcomes in our cohort. CVD comorbidity was associated with relatively poor PTA outcomes. To confirm our findings, larger cohort studies with a longer follow-up period are warranted.

Atypical moyamoya syndrome with brain calcification and stenosis of abdominal aorta and renal arteries

Moyamoya syndrome is a progressive cerebrovascular disease that is characterized by stenosis of the terminal portion of the internal carotid artery and its main branches, in combination with an accompanying disease. We herein describe an 8-year-old boy exhibiting transient loss of consciousness, who had recurrent seizures in infancy with progressive brain calcification. On admission, he was alert but magnetic resonance angiography showed bilateral stenosis of the whole internal carotid artery and proliferation of vascular collaterals, and brain CT revealed calcification on bilateral putamen. Given that this fulfilled diagnostic criteria, we finally diagnosed him as having moyamoya syndrome, though the etiology was unclear. Interestingly, a whole vessel survey revealed vascular stenosis of abdominal aorta and renal arteries, in which the former has not been reported in moyamoya syndrome. We considered that brain calcification was gradually formed by decreased cerebral vascular flow from infancy, and stenosis of abdominal aorta was possibly extended from renal arteries. This is, moyamoya syndrome with brain calcification and stenosis of abdominal aorta, suggesting that morphological screening of whole vessels containing cerebral and abdominal arteries should be considered in cases of slowly progressive brain calcification.

Prevalence of and risk factors for enlarged perivascular spaces in adult patients with moyamoya disease

Background

Enlarged perivascular spaces (EPVS) are often observed with magnetic resonance imaging in patients with small vessel disease. However, the risk factors, radiological features, and clinical relevance of EPVS in patients with moyamoya disease are poorly understood. The purpose of this study was to evaluate EPVS, the risk factors of many EPVS, and the pathophysiology of EPVS in adult patients with moyamoya disease.

Methods

One hundred cerebral hemispheres of 50 adult patients with moyamoya disease were examined. The control group consisted of 50 age/sex-matched patients without ischemic disease. The numbers of EPVS at the level of the centrum semiovale per hemisphere were compared between the moyamoya disease and control groups. In each hemisphere, the total numbers of EPVS were categorized into five grades (0–4), and the clinical and radiological characteristics of the predictive factors in patients in the high EPVS grade group (EPVS grade = 4) were assessed.

Results

The EPVS counts and grades were significantly higher in the moyamoya disease group. Analyses of the background characteristics of the patients with moyamoya disease revealed that significantly higher prevalence of high EPVS grades were associated with the female sex, hypertension, high magnetic resonance angiography scores, high numbers of flow voids in the basal ganglia, high brain atrophy scores, ivy signs, and white matter lesions. A logistic multivariate analysis of the patients with high EPVS grades revealed significant associations with the female sex, hypertension, and flow voids in the basal ganglia.

Conclusions

Increased EPVS were confirmed in adult patients with moyamoya disease, and the associated clinical and radiological factors were identified. The presence of hypertension, the female sex, and flow voids in the basal ganglia were important for predicting high EPVS grades in patients with moyamoya disease. Reductions in arterial pulsations with steno-occlusive changes can inhibit the flow of interstitial fluid, which can increase the number of EPVS in patients with moyamoya disease. Other clinical factors, such as the female sex and hypertension, may promote secondary brain damage in patients with moyamoya disease. Further evaluations of EPVS in patients with moyamoya disease are needed to better understand their pathophysiological importance.

Histopathological features of middle cerebral artery and superficial temporal artery from patients with moyamoya disease and enlightenments on clinical treatment

The histopathological features of the middle cerebral artery (MCA) and superficial temporal artery (STA) from moyamoya disease (MMD) and their relationships with gender, age, angiography stage were explored. The causes and the clinical significance of vasculopathy of STA were also discussed. The clinical data and specimens of MCA and STA from 30 MMD patients were collected. Twelve samples of MCA and STA from non-MMD patients served as control group. Histopathological examination was then performed by measuring the thickness of intima and media, and statistical analysis was conducted. The MCA and STA specimens from MMD group had apparently thicker intima and thinner media than those from the control group. There was no significant pathological difference between the hemorrhage group and non-hemorrhage group, and between the males and females in MMD patients. Neither the age nor the digital subtraction angiography (DSA) stage was correlated with the thickness of intima in MCA and STA. MMD is a systemic vascular disease involving both intracranial and extracranial vessels. Preoperative external carotid arteriography, especially super-selective arteriography of the STA, benefits the selection of donor vessel.

Prevalence and clinical implications of renal artery stenosis in pediatric moyamoya disease

PURPOSE

Until recently, extracranial involvement of moyamoya disease (MMD) had not been fully elucidated. The purpose of this study was to determine the prevalence and clinical implications of renal artery stenosis in pediatric MMD patients.

MATERIALS & METHODS

This retrospective study included 101 pediatric (<18 years old) MMD patients who visited our hospital from July 2008 to May 2013. All patients had legible abdominal or renal angiography. Baseline characteristics, including hypertension (HT) and angiographic findings, were retrospectively evaluated.

RESULT

The median age was 8 (range 2-16) years. Six patients (5.9%) had HT. Renal artery stenosis was identified in 8 patients (7.9%). Five of 8 renal artery stenosis patients had HT. Statistical analysis showed that advanced stages of MMD and HT were associated with renal artery stenosis (p < 0.05).

CONCLUSION

Renal artery stenosis was not uncommon in pediatric MMD. Renal artery evaluation could help determine the cause of HT in advanced pediatric MMD cases. Further prospective and large-scale studies may be helpful in elucidating the extracranial manifestation of MMD.

A new horizon of moyamoya disease and associated health risks explored through RNF213

The cerebrovascular disorder moyamoya disease (MMD) was first described in 1957 in Japan, and is typically considered to be an Asian-specific disease. However, it is globally recognized as one of the major causes of childhood stroke. Although several monogenic diseases are known to be complicated by Moyamoya angiopathy, the ring finger protein 213 gene (RNF213) was identified as a susceptibility gene for MMD. RNF213 is unusual, because (1) it induces MMD with no other recognizable phenotypes, (2) the RNF213 p.R4810K variant is an Asian founder mutation common to Japanese, Korean and Chinese with carrier rates of 0.5–2 % of the general population but a low penetrance, and (3) it encodes a relatively largest proteins with a dual AAA+ ATPase and E3 Ligase activities. In this review, we focus on the genetics and genetic epidemiology of RNF213, the pathology of RNF213 R4810K, and the molecular functions of RNF213, and also address the public health contributions to current unresolved issues of MMD. We also emphasize the importance of a more updated definition for MMD, of qualified cohort studies based on genetic epidemiology and an awareness of the ethical issues associated with genetic testing of carriers.

Research Progress of Moyamoya Disease in Children

During the onset of Moyamoya disease (MMD), progressive occlusion occurs at the end of the intracranial internal carotid artery, and compensatory net-like abnormal vessels develop in the skull base, generating the corresponding clinical symptoms. MMD can affect both children and adults, but MMD in pediatric patients exhibits distinct clinical features, and the treatment prognoses are different from adult patients. Children are the group at highest risk for MMD. In children, the disease mainly manifests as ischemia, while bleeding is the primary symptom in adults. The pathogenesis of MMD in children is still unknown, and some factors are distinct from those in adults. MMD in children could result in progressive, irreversible nerve functional impairment, and an earlier the onset corresponds to a worse prognosis. Therefore, active treatment at an early stage is highly recommended. The treatment methods for MMD in children mainly include indirect and direct surgeries. Indirect surgeries mainly include multiple burr-hole surgery (MBHS), encephalomyosynangiosis (EMS), and encephaloduroarteriosynangiosis (EDAS); direct surgeries mainly include intra- and extracranial vascular reconstructions that primarily consist of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. Indirect surgery, as a treatment for MMD in children, has shown a certain level of efficacy. However, a standard treatment approach should combine both indirect and direct procedures. Compared to MMD in adults, the treatment and prognosis of MMD in children has higher clinical significance. If the treatment is adequate, a satisfactory outcome is often achieved.

Variant angina in moyamoya disease--a correlative etiology and different presentation: a case report

INTRODUCTION

Moyamoya disease is characterized by progressive steno-occlusive changes of the distal internal carotid and developed collateral vasculature, so called 'moyamoya' vessels at the base of the brain. Variant angina is a rare occurrence in patients with moyamoya disease.

CASE PRESENTATION

Here we report the case of a 41-year-old Korean woman who developed chest pain after indirect revascularization surgery of moyamoya disease. A treadmill test and an exercise stress echocardiograph showed positive results, but there was no significant major coronary arteries stenosis. Suspicious of vasospasm, we conducted an ergonovine spasm stimulation test, which demonstrated tight stenosis of her proximal left anterior descending artery. At the site of spasm, intravascular ultrasound virtual histology showed intraluminal fibrous plaque.

CONCLUSION

Physicians who follow up patients with moyamoya disease would need to be aware of the possibility of cardiac ischemia as well as neurological manifestations.

Coronary heart disease in moyamoya disease: are they concomitant or coincidence?

The purpose of this study was to determine the prevalence and characteristics of symptomatic coronary heart disease (CHD) in patients with moyamoya disease (MMD). This retrospective study evaluated 456 patients who received examination for MMD between 1995 and 2012. We reviewed the patients' medical history and coronary imaging, including conventional coronary angiography and coronary computed tomography angiogram (CTA). Among 456 patients with MMD, 21 (4.6%) patients were found to have symptomatic CHD. Ten patients were treated with coronary artery bypass graft or percutaneous coronary intervention for unstable angina or myocardial infarction. Eleven were treated with medication for stable angina (n = 6) and variant angina with mild degree of stenosis (n = 5).The median age of these patients was 44 yr (range, 27-59). The median Framingham score at diagnosing MMD was < 1% (range, < 1%-16%). The old age was associated with CHD in uni- and multivariate analyses (P = 0.021, OR, 1.053; 95% CI, 1.008-1.110). Considering low age of onset and low stroke risk factor, CHD might be a systemic manifestation that is clinically relevant to MMD.

External carotid stenting for symptomatic stenosis in a patient with patent EDAS for Moyamoya disease

BACKGROUND

Moyamoya disease is characterized by progressive narrowing of the internal carotid artery (ICA). Symptomatic patients typically undergo cerebrovascular intervention via extracranial-intracranial (EC-IC) bypass, most often with the use of the superficial temporal artery. This case of Moyamoya disease is of particular interest as the patient presented with a unilateral atherosclerotic external carotid artery (ECA) stenosis after EC-IC bypass that eliminated the benefit of his original surgery, resulting in a symptomatic presentation.

CLINICAL PRESENTATION

A 53-year-old man presenting with Moyamoya disease and known left ICA occlusion had received a bilateral encephaloduroarteriosynangiosis (EDAS) bypass 10 years previously. He re-presented complaining of right-sided tingling, weakness, and numbness radiating up the arm. CT angiography indicated significant stenosis of the left ECA. ECA angioplasty and stenting with a distal protection device resulted in resolution of his symptoms.

CONCLUSIONS

This case illustrates that a patient presenting with Moyamoya disease and concurrent symptomatic ECA stenosis post-EDAS can be effectively and safely treated with ECA stenting.

External carotid stenting for symptomatic stenosis in a patient with patent EDAS for Moyamoya disease

BACKGROUND

Moyamoya disease is characterized by progressive narrowing of the internal carotid artery (ICA). Symptomatic patients typically undergo cerebrovascular intervention via extracranial-intracranial (EC-IC) bypass, most often with the use of the superficial temporal artery. This case of Moyamoya disease is of particular interest as the patient presented with a unilateral atherosclerotic external carotid artery (ECA) stenosis after EC-IC bypass that eliminated the benefit of his original surgery, resulting in a symptomatic presentation.

CLINICAL PRESENTATION

A 53-year-old man presenting with Moyamoya disease and known left ICA occlusion had received a bilateral encephaloduroarteriosynangiosis (EDAS) bypass 10 years previously. He re-presented complaining of right-sided tingling, weakness, and numbness radiating up the arm. CT angiography indicated significant stenosis of the left ECA. ECA angioplasty and stenting with a distal protection device resulted in resolution of his symptoms.

CONCLUSIONS

This case illustrates that a patient presenting with Moyamoya disease and concurrent symptomatic ECA stenosis post-EDAS can be effectively and safely treated with ECA stenting.

Moyamoya syndrome and neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is the most prevalent autosomal dominant genetic disorder among humans. NF1 vasculopathy is a significant but underrecognized complication of the disease, affecting both arterial and venous blood vessels of all sizes. Moyamoya syndrome is a cerebral vasculopathy that is only rarely observed in association with NF1, particularly in the pediatric age range. Herein, we report of a 5-year-old female with NF1 and moyamoya syndrome and we briefly review the existing literature.

Aggressive blood pressure control for chronic kidney disease unmasks moyamoya!

Hypertensive crises in children or adolescents are rare, but chronic kidney disease (CKD) is a major risk factor for occurrence. Vesicoureteral reflux nephropathy is a common cause of pediatric renal failure and is associated with hypertension. Aggressive blood pressure (BP) control has been shown to delay progression of CKD and treatment is targeted for the 50th percentile for height when compared with a target below the 90th percentile for the general pediatric hypertensive patient. We present a case of an adolescent presenting with seizures and renal failure due to a hypertensive crisis. Hypertension was thought to be secondary to CKD as she had scarred echogenic kidneys due to known reflux nephropathy. However, aggressive BP treatment improved kidney function which is inconsistent with CKD from reflux nephropathy. Secondly, aggressive BP control caused transient neurological symptoms. Further imaging identified moyamoya disease. We present this case to highlight the consideration of moyamoya as a diagnosis in the setting of renal failure and hypertensive crisis.

How commonly do children with complex cerebral arteriopathy have renovascular disease?

AIM

To describe the frequency of renovascular abnormalities and hypertension in an opportunistic cohort of children with complex cerebrovascular disease from a single tertiary/quaternary referral centre.

METHOD

This was a retrospective case note and imaging review of children who had had cerebral and renal angiography, with a diagnosis of moyamoya or other occlusive cerebrovascular disease (OCVD). Hypertension was defined as at least three systolic blood pressure readings of the 95th centile or above.

RESULTS

Of 34 children (12 males, 22 females; median age 5y 11mo, range 2mo-15y 3mo; 20 with moyamoya, 14 with OCVD), primary presentation was neurological in 29 (arterial ischaemic stroke, transient ischaemic attack, or headache) and with hypertension in five. Renovascular abnormalities were identified in 17, of whom 10 had main renal artery stenosis. Renovascular involvement was not predictable according to arteriopathy diagnosis. Blood pressure was rarely plotted on centile charts. Using the 50th height centile for blood pressure, and based on a median of five systolic blood pressure readings per patient, 20 out of 34 met the definition for hypertension (15/29 patients with primary neurological presentation).

INTERPRETATION

Renovascular abnormalities were common in this group of children with complex cerebrovascular disease. Blood pressure was frequently abnormal but rarely measured and infrequently plotted on centile charts. Neurologists should be alert to potential systemic vascular involvement and its sequelae in children with complex cerebrovascular disease.