A co-operative study: clinical characteristics of 334 Korean patients with moyamoya disease treated at neurosurgical institutes (1976-1994). The Korean Society for Cerebrovascular Disease

Vessel wall MRI in moyamoya disease: arterial wall enhancement varies depending on age, arteries, and disease progression

OBJECTIVE

To investigate the relationship of followings for patients with moyamoya disease (MMD): arterial wall enhancement on vessel wall MRI (VW-MRI), cross-sectional area (CSA), time-of-flight MR angiography (MRA), age, locations from intracranial internal carotid artery (ICA) to proximal middle cerebral artery (MCA), disease progression, and transient ischemic attack (TIA).

METHODS

Patients who underwent VW-MRI between October 2018 and December 2020 were enrolled in this retrospective study. We measured arterial wall enhancement (enhancement ratio, ER) and CSA at five sections of ICA and MCA. Also, we scored MRA findings. Multiple linear regression (MLR) analysis was performed to explore the associations between ER, age, MRA score, CSA, history of TIA, and surgical revascularization.

RESULTS

We investigated 102 sides of 51 patients with MMD (35 women, 16 men, mean age 31 years ± 18 [standard deviation]). ER for MRA score 2 (signal discontinuity) was higher than ER for other scores in sections D (end of ICA) and E (proximal MCA) on MLR analysis. ER in section E was significantly higher in patients for MRA score 2 with TIA history than without. ER significantly increased as CSA increased in section E, which suggests ER becomes less in decreased CSA due to negative remodeling.

CONCLUSION

Arterial wall enhancement in MMD varies by age, location, and disease progression. Arterial wall enhancement may be stronger in the progressive stage of MMD. Arterial wall enhancement increases with history of TIA at proximal MCA, which may indicate the progression of the disease.

CLINICAL RELEVANCE STATEMENT

Arterial wall enhancement in moyamoya disease varies by age, location of arteries, and disease progression, and arterial wall enhancement may be used as an imaging biomarker of moyamoya disease.

KEY POINTS

It has not been clarified what arterial wall enhancement in moyamoya disease represents. Arterial wall enhancement in moyamoya disease varies by age, location of arteries, and disease progression. Arterial wall enhancement in moyamoya disease increases as the disease progresses.

Proteomic and metabolomic characterizations of moyamoya disease patient sera

BACKGROUND

The pathogenesis of moyamoya disease (MMD) is unclear. Inflammation and immune imbalance have been identified as potential factors contributing to the occurrence and progression of MMD. However, the specific proteins and metabolites responsible for triggering this process are yet to be established. The purpose of this study is to identify differentially expressed proteins and metabolites in patients with MMD and perform Kyoto Encyclopedia of Genes and Genomes pathway integration analysis to pinpoint crucial proteins and metabolites involved in the disease.

METHODS

We performed untargeted metabolomic and data-independent acquisition proteomic analyses on the serum samples of individuals with MMD and healthy controls (HC).

RESULTS

In patients with MMD versus HC, 24 proteins and 60 metabolites, including 21 anionic metabolites and 39 cationic metabolites, which were significantly different, were identified. In patients with MMD, several proteins involved in inflammation and immune metabolism, such as tubulin beta-6 and complement C4, were found to have significantly altered levels. Similarly, many metabolites involved in inflammation and immune metabolisms, such as dimethyl 4-hydroxyisophthalate, beta-nicotinamide mononucleotide, 2-(3-(4-pyridyl)-1H-1,2,4-triazol-5-yl)pyridine, and PC (17:1/18:2), were significantly altered. Intriguingly, these proteins and metabolites are involved in the progression of atherosclerosis through immune and inflammatory pathways, although some have never been reported in MMD. Moreover, integrated proteomics and metabolomics studies were conducted to determine shared pathways involving cholesterol metabolism, vitamin digestion, fat digestion, and absorption pathways of proteins and metabolites, which warrant further investigation.

CONCLUSIONS

Significant increases in pro-inflammatory and immunosuppressive abilities have been observed in patients with MMD, accompanied by significant reductions in anti-inflammatory and immune regulation. Various metabolites and proteins implicated in these processes have been identified for the first time. These findings hold immense significance for comprehending the pathogenesis of MMD and for the development of future drug therapies.

Revascularization Surgery for Moyamoya Vasculopathy: An Australian Experience

BACKGROUND

Moyamoya vasculopathy is a rare steno-occlusive cerebrovascular disorder presenting with ischemia or hemorrhage. There are racial and geographic differences in presentation and outcome. There is little information regarding moyamoya in Australia.

METHODS

Moyamoya patients undergoing surgery from 2001 to 2022 were studied retrospectively. The outcomes of revascularization surgery in adult and pediatric patients, with ischemic and hemorrhagic disease were analyzed, including functional outcomes, postoperative complications, bypass patency, and long-term rates of ischemic and hemorrhagic events.

RESULTS

A total of 68 patients with 122 revascularized hemispheres and 8 posterior circulation revascularizations were included in this study. Eighteen patients were of Asian descent and 46 were of Caucasian origin. Presentation was with ischemia in 124 hemispheres and hemorrhage in six hemispheres. There were 92 direct, 34 indirect, and 4 combined revascularization surgeries performed. Early postoperative complications occurred in 3.1% (n = 4) of operations and delayed complications (infection, subdural hematoma) occurred after 4.6% (n = 6) of operations. Mean follow-up was 6.5 years (3-252 months). There was 100% patency of direct grafts at last follow-up. There were no hemorrhagic events following surgery and 1 new ischemic event 2 years after surgery. There was significant improvement in physical health functional outcomes at most recent follow-up (P < 0.05); mental health outcomes were not different between preoperative and postoperative assessments.

CONCLUSIONS

The majority of Australian moyamoya patients are Caucasian and the most common clinical presentation is ischemia. Revascularization surgery had excellent outcomes with very low rates of ischemia and hemorrhage, comparing favorably to the natural history of moyamoya vasculopathy.

Ethnic-Associated Phenotype Variations in Moyamoya Cerebrovascular Outcomes

INTRODUCTION

Moyamoya has been extensively described in East Asian populations, and despite its accepted clinical presentation and course, it is fundamental to describe major cerebrovascular complications in other ethnically diverse samples. Hence, we sought to determine if distinct ethnic groups are at higher risk of developing stroke using the National Inpatient Sample (NIS) database.

METHODS

We included all moyamoya patients admitted from January 2013 until December 2018 in the NIS database. Multivariate regression analysis was used to determine the risk of developing stroke and poor outcomes in different races compared to white patients.

RESULTS

Out of the 6093 admissions with diagnosis of moyamoya disease that were captured, 2,520 were white (41.6%), 2,078 were African American (AA) (34.1%), 721 were Hispanic (11.8%), and 496 were Asian (8.14%). For arterial ischemic stroke (AIS), we found that AA race had a significantly reduced risk of AIS compared to white patients (odds ratio = 0.8, 95% confidence interval: 0.7-0.9, p = 0.031). While being Hispanic or Asian significantly increased 1.5 and 2-fold the risk of hemorrhagic stroke.

CONCLUSION

This study highlights the unique features and phenotypes of moyamoya cases among different ethnicities. While possibly AA are protected from developing AIS due to underlying causes of moyamoya such as sickle cell disease, Asians seems to be more susceptible to hemorrhagic stroke.

Long-term mortality in patients with moyamoya angiopathy according to stroke presentation type in South Korea

BACKGROUND

Incidence, prevalence, and long-term survival outcomes in patients with moyamoya angiopathy (MMA) according to stroke presentation type and age group have not been clearly elucidated.

METHODS

We investigated mortality in patients with MMA (moyamoya disease, probable moyamoya disease, moyamoya syndrome) of whose International Classification Disease 10 code was I67.5 from 2006 to 2015 using the Korean National Health Insurance database. MMA at diagnosis was classified into 3 types (ischemic, hemorrhagic, and asymptomatic or else) according to stroke presentation. Survival analysis was performed according to stroke presentation type and age group (< 15 years and ≥ 15 years) using the Kaplan-Meier method.

RESULTS

There were 12,146 newly diagnosed moyamoya cases, with a female-to-male ratio of 1.81; the ischemic type was identified in 3671 (30.2%) patients, the hemorrhagic type in 2449 (20.2%) patients, and the asymptomatic or else type in 6026 (49.6%) patients. The mean age at diagnosis according to stroke presentation was 33.1 (± 14.8) years in asymptomatic or else type, 41.2 (± 17.3) years in ischemic type, and 45.4 (± 14.3) years in hemorrhagic type (P < 0.001). The 10-year survival rates in ischemic-, hemorrhagic-, and asymptomatic or else-type patients were 88.9%, 76.3%, and 94.3%, respectively (log-rank test; P < 0.001). Pediatric MMA (< 15 years) and adult MMA (≥ 15 years) showed different survival curves according to stroke presentation type (log-rank test; P = 0.017, P < 0.001, respectively).

CONCLUSIONS

Our study showed that moyamoya patients had different diagnosis ages and distinct survival courses according to stroke presentation type. Adult moyamoya patients with hemorrhagic presentation had the worst survival outcomes.

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.

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.

Differences in Clinical Features among Different Onset Patterns in Moyamoya Disease

Moyamoya disease is characterized by severe stenosis at the ends of the bilateral internal carotid arteries and the development of collateral circulation. The disease is very diverse in terms of age at onset, onset patterns, radiological findings, and genetic phenotypes. The pattern of onset is mainly divided into ischemic and hemorrhagic onsets. Recently, the opportunity to identify asymptomatic moyamoya disease, which sometimes manifests as nonspecific symptoms such as headache and dizziness, through screening with magnetic resonance imaging has been increasing. Various recent reports have investigated the associations between the clinical features of different onset patterns of moyamoya disease and the corresponding imaging characteristics. In this article, we have reviewed the natural history, clinical features, and imaging features of each onset pattern of moyamoya disease.

Significance of Serum Angiopoietin-2 in Patients with Hemorrhage in Adult-Onset Moyamoya Disease

Background

Moyamoya disease (MMD) is a progressive occlusive cerebrovascular disease that is characterized by abnormal angiogenesis at the base of the brain. This pathological abnormal angiogenesis is susceptible to disturbances, including spontaneous hemorrhage and vasogenic edema. However, the underlying mechanisms of pathological angiogenesis and occurrence of hemorrhage are unclear. Angiopoietins play a fundamental role in the pathophysiology of central nervous system disorders in angiogenesis. This study was aimed at examining whether angiopoietins are associated with formation of abnormal collateral vessels and the occurrence of hemorrhage in adult-onset moyamoya disease (HMMD).

Methods

A total of 27 consecutive adult patients with HMMD were enrolled from June 2011 to May 2017. Serum levels of angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) were examined by enzyme-linked immunosorbent assay. Patients with HMMD were compared with those with spontaneous hemorrhage (controls) and nonhemorrhagic-onset MMD (NHMMD).

Results

Serum Ang-2 levels were significantly higher in patients with adult HMMD than in those with spontaneous hemorrhage and NHMMD. The ROC curve identified that a baseline serum Ang-2 level > 1230 ng/ml may be associated with adult HMMD with 88.39% sensitivity and 70.37% specificity (area under the curve (AUC), 0.89; 95% CI, 0.808-0.973; P < 0.001). Moreover, serum Ang-2 levels were significantly elevated in stages II, III, and IV. In subgroup analysis of a high and low degree of moyamoya vessels, serum Ang-2 levels were significantly higher in the high moyamoya vessel group than in the low moyamoya vessel group. Serum Ang-2 levels were also significantly higher in the low moyamoya vessel group compared with the control group. Serum Ang-1 levels were not significantly different among the groups.

Conclusion

Increased serum Ang-2 levels may contribute to pathological abnormal angiogenesis and/or to the instability of vascular structure and function, thus causing brain hemorrhage in adult HMMD.

Moyamoya disease and moyamoya syndrome in Ireland: patient demographics, mode of presentation and outcomes of EC-IC bypass surgery

BACKGROUND

There are no previously published reports regarding the epidemiology and characteristics of moyamoya disease or syndrome in Ireland.

AIMS

To examine patient demographics, mode of presentation and the outcomes of extracranial-intracranial bypass surgery in the treatment of moyamoya disease and syndrome in Ireland.

METHODS

All patients with moyamoya disease and syndrome referred to the National Neurosurgical Centre during January 2012-January 2019 were identified through a prospective database. Demographics, clinical presentation, radiological findings, surgical procedures, postoperative complications and any strokes during follow-up were recorded.

RESULTS

Twenty-one patients were identified. Sixteen underwent surgery. Median age at diagnosis was 19 years. Fifteen were female. Mode of presentation was ischaemic stroke in nine, haemodynamic TIAs in eight, haemorrhage in three and incidental in one. Sixteen patients had Moyamoya disease, whereas five patients had moyamoya syndrome. Surgery was performed on 19 hemispheres in 16 patients. The surgical procedures consisted of ten direct (STA-MCA) bypasses, five indirect bypasses and four multiple burr holes. Postoperative complications included ischaemic stroke in one patient and subdural haematoma in one patient. The median follow-up period in the surgical group was 52 months; there was one new stroke during this period. Two patients required further revascularisation following recurrent TIAs. One patient died during follow-up secondary to tumour progression associated with neurofibromatosis type 1.

CONCLUSIONS

Moyamoya is rare but occurs in Caucasians in Ireland. It most commonly presents with ischaemic symptoms. Surgical intervention in the form of direct and indirect bypass is an effective treatment in the majority of cases.

Effect of choroidal collateral vessels on de novo hemorrhage in moyamoya disease: analysis of nonhemorrhagic hemispheres in the Japan Adult Moyamoya Trial

OBJECTIVE

Following hemorrhagic stroke in moyamoya disease, de novo intracranial hemorrhage can occur in the previously unaffected nonhemorrhagic hemisphere. In the present analysis the authors intended to determine whether the presence in the nonhemorrhagic hemisphere of choroidal collateral vessels, which have been the focus of attention as a source of bleeding, affects the risk of de novo hemorrhage.

METHODS

The subject of focus of the present cohort study was the nonhemorrhagic hemispheres of adult patients with hemorrhagic moyamoya disease enrolled in the Japan Adult Moyamoya Trial and allocated to the nonsurgical arm. The variable of interest was the presence of choroidal collaterals (also termed choroidal anastomoses), identified with baseline angiography and represented by a connection (anastomosis) between the anterior or posterior choroidal arteries and the medullary arteries. The outcome measure was de novo hemorrhage during the 5-year follow-up period, assessed in all nonhemorrhagic hemispheres. The incidence of de novo hemorrhage in the collateral-positive and -negative groups was compared.

RESULTS

Choroidal collaterals were present in 15 of 36 (41.7%) nonhemorrhagic hemispheres analyzed. The overall annual risk of de novo hemorrhage was 2.0%. Three de novo hemorrhages occurred in the collateral-positive group, whereas no hemorrhage occurred in the collateral-negative group. The annual risk of de novo hemorrhage was significantly higher in the collateral-positive group than in the collateral-negative group (5.8% per year vs 0% per year; p = 0.017). All hemorrhage sites corresponded to the distribution of choroidal collaterals.

CONCLUSIONS

The present preliminary results suggest that the presence of choroidal collaterals affects the risk of de novo hemorrhage in the nonhemorrhagic hemisphere, subject to verification in larger studies. Further studies are needed to determine the optimal treatment strategy for nonhemorrhagic hemispheres and asymptomatic patients.

Coexisting Moyamoya Syndrome and Type 1 Diabetes Mellitus: A Case Report and Review of the Literature

Moyamoya disease (MMD) is an incompletely understood malady that affects many age groups, primarily in a bimodal age distribution. We present a patient with the association of type 1 diabetes mellitus (type 1 DM) and MMD followed by a review of the existing literature. We found five papers that describe this association, in the form of one case report, one case series, and three retrospective reviews. Despite a poor understanding of the underlying pathophysiology, a clear association between autoimmune conditions and MMD appears to exist. Clinicians who manage such patients ought to be vigilant and have a high index of suspicion when young patients with type 1 DM present with new onset of neurological symptoms.

Anesthetic challenges in pediatric moyamoya disease: A report of two cases

Moyamoya disease (MMD), a rare cause of pediatric stroke, is a cerebrovascular occlusive disorder resulting from progressive stenosis of the distal intracranial carotid arteries and their proximal branches. In response to brain ischemia, there is the development of basal collateral vessels, which gives rise to the characteristic angiographic appearance of moyamoya (puff of smoke). If left untreated, the disease can result in overwhelming permanent neurological and cognitive deficits. Whereas MMD refers to the idiopathic form, moyamoya syndrome refers to the condition in which children with moyamoya also have a recognized clinical disorder. The classic pediatric presentation in moyamoya is recurrent transient ischemic attacks (TIAs) and/or completed/repeated ischemic strokes. Surgical revascularization, including direct and indirect techniques, remains the mainstay of treatment and has been shown to improve long-term outcome in children with MMD. Various risk factors identified for perioperative complications are as follows: history of TIAs, severity of disease, intraoperative hypotension, hypercapnia and hypovolemia, and substantial reduction in hematocrit intraoperatively. Thus, providing perianesthetic care to pediatric patients undergoing revascularization procedure for MMD is like walking a tightrope, and we present two such cases handled successfully.

The Targeted Bypass Strategy for Preventing Hemorrhage in Moyamoya Disease: Technical Note

Although direct bypass is effective at preventing intracranial hemorrhage in moyamoya disease, the optimal strategy for achieving this purpose has rarely been addressed. The tailored targeting bypass strategy is a novel technical modification of direct bypass focused on hemorrhage prevention. The strategy is based on the promising theory of periventricular anastomosis, which explains the mechanism of hemorrhage in moyamoya disease. The strategy is defined as the use of multi-imaging modalities to predetermine in a tailored manner a target vessel at the point at which the medullary artery directly extends from the periventricular anastomosis of interest. Direct bypass with a wide craniotomy was performed on 13 hemispheres in eight patients according to this strategy. Marked shrinkage of the periventricular anastomosis of interest was observed in all but one hemisphere after surgery, and no new hemorrhages have occurred as of this writing. The present case series illustrates the technical aspects and preliminary results of the tailored targeting bypass strategy, an approach that might expand the potential of direct bypass in preventing hemorrhage.

Identification of the Bleeding Point in Hemorrhagic Moyamoya Disease Using Fusion Images of Susceptibility-Weighted Imaging and Time-of-Flight MRA

BACKGROUND AND PURPOSE

The location of intracerebral hemorrhage in Moyamoya disease is a prognostic factor for rebleeding and the degree of preventive effects obtainable with bypass surgery. We evaluated whether the bleeding point and responsible vessel were detectable using fusion images of SWI and time-of-flight MRA performed during chronic-phase hemorrhage.

MATERIALS AND METHODS

We retrospectively enrolled 42 patients with hemorrhagic Moyamoya disease (48 hemorrhagic events). Fusion images of SWI and MRA were made using workstations, and we defined the bleeding point as the point at which the signal of an abnormally extended artery on MRA overlapped the hypointense area on SWI. Two independent raters identified the bleeding point, and classified the location and responsible vessels.

RESULTS

The bleeding point was detectable at a frequency of 79.2% by rater 1. Agreement for the presence of a bleeding point was high (interrater κ = 0.83; 95% CI, 0.65-1; intrarater κ = 0.86; 95% CI, 0.68-1). The frequency of a periventricular location of the bleeding point was 65.8% by rater 1, and agreement on the location was again high (interrater κ = 0.92; 95% CI, 0.82-1; intrarater κ = 0.85; 95% CI, 0.72-0.99). The choroidal artery was the most frequent responsible vessel (57.9% by rater 1), and agreement on the responsible vessel was high (interrater κ = 0.84; 95% CI, 0.69-1; intrarater κ = 0.90; 95% CI, 0.78-1).

CONCLUSIONS

Detection of the bleeding point in hemorrhagic Moyamoya disease using SWI and MRA fusion images offers highly reproducible results.

A perfusion territory shift attributable solely to the secondary collaterals in moyamoya patients: a potential risk factor for preoperative hemorrhagic stroke revealed by t-ASL and 3D-TOF-MRA

OBJECTIVE

The authors conducted a study to noninvasively and nonradioactively reveal moyamoya disease (MMD) intracerebral perfusion and perfusion territory supplied by the unilateral internal carotid artery (ICA) and external carotid artery (ECA) and bilateral vertebral arteries (VAs) before surgery and to further identify risk factors for preoperative hemorrhage in adult MMD.

METHODS

Forty-three consecutive adult patients with bilateral MMD underwent unenhanced T1-weighted MRI, territorial arterial spin labeling (t-ASL), and unenhanced 3D time-of-flight MRA (3D-TOF-MRA). Clinical factors, including age, sex, hypertension, diabetes mellitus, hyperlipidemia, current smoking status, and history of taking aspirin, were gathered and stratified. Univariate logistic regression analyses were used to examine the relationship between various risk factors and the occurrence of preoperative hemorrhage. Stepwise multivariate logistic regression analyses were used to determine independent risk factors of preoperative hemorrhage in MMD.

RESULTS

Among the 86 MMD hemispheres, t-ASL revealed 137 perfusion territory shifts in 79 hemispheres. Five distinct categories of perfusion territory shifts were observed on t-ASL maps. The subtypes of perfusion territory shift on t-ASL maps were further subdivided into 2 different categories, group A and group B, in combination with findings on 3D-TOF-MRA. A perfusion territory shift attributable solely to the secondary collaterals was a potential independent risk factor for preoperative hemorrhage (p = 0.026; 95% CI 1.201-18.615; OR 4.729). After eliminating the influence of the secondary collaterals, the primary collaterals had no significant effect on the risk of preoperative hemorrhage (p = 0.182).

CONCLUSIONS

t-ASL could reveal comprehensive MMD cerebral blood perfusion and the vivid perfusion territory shifts fed by the unilateral ICA and ECA and bilateral VAs in a noninvasive, straightforward, nonradioactive, and nonenhanced manner. 3D-TOF-MRA could subdivide t-ASL perfusion territory shifts according to their shunt arteries. A perfusion territory shift attributable to the secondary collaterals is a potential independent risk factor for preoperative hemorrhage in MMD patients. A perfusion territory shift fed by the primary collaterals may not have a strong effect on preoperative hemorrhage in MMD patients. These findings make the combined modalities of t-ASL and 3D-TOF-MRA a feasible tool for MMD disease assessment, management, and surgical strategy planning.

Encephaloduroarteriosynangiosis for hemorrhagic moyamoya disease: long-term outcome of a consecutive series of 95 adult patients from a single center

OBJECTIVE

The objective of this study was to investigate long-term outcomes after encephaloduroarteriosynangiosis (EDAS) for the treatment of hemorrhagic moyamoya disease (MMD) and identify the risk factors for recurrent hemorrhages.

METHODS

The authors retrospectively reviewed 95 patients with hemorrhagic MMD who were treated with EDAS at 307th Hospital PLA. Clinical features, angiographic findings, and clinical outcomes were investigated. Rebleeding incidences were compared between anterior or posterior hemorrhagic sites. Kaplan-Meier survival analysis and Cox proportional hazards regression models were used to estimate rebleeding risks after EDAS.

RESULTS

The average age at symptom onset was 37.1 years (range 20-54 years) for adult patients. The ratio of female to male patients was 1.16:1. In 61 of 95 hemorrhagic hemispheres (64.2%), the anterior choroidal artery (AChA) or posterior communicating artery (PCoA) was extremely dilated, with extensive branches beyond the choroidal fissure, which only occurred in 28 of 86 nonhemorrhagic hemispheres (32.6%). Fifty-seven incidences were classified as anterior hemorrhages and 38 as posterior. Sixteen of 95 patients (16.8%) suffered cerebral rebleeding after a median follow-up duration of 8.5 years. The annual rebleeding rate was 2.2% per person per year. The incidence rate was higher for the posterior group than for the anterior group, but this difference was not statistically significant (p > 0.05). Cox regression analysis revealed that the age of symptom onset (OR 1.075, 95% CI 1.008-1.147, p = 0.028) was a predictor of rebleeding strokes.

CONCLUSIONS

Through long-term follow up, EDAS proved beneficial for patients with hemorrhagic MMD. Dilation of the AChA-PCoA is associated with the initial hemorrhage of MMD, and rebleeding is age-related. Patients with hemorrhagic MMD should undergo follow-up over the course of their lives, even when neurological status is excellent.

Revascularization Surgery in Patients with Ischemic-Type Moyamoya Disease: Predictors for Postoperative Stroke and Long-Term Outcomes

BACKGROUND

Recurrent stroke after surgical revascularization is still a big issue for moyamoya disease (MMD). This study aims to identify predictors for postoperative stroke and unfavorable outcome in ischemic-type MMD.

METHODS

We identified a consecutive series of patients with ischemic-type MMD who underwent revascularization between January 2005 and December 2012. Predictors for postoperative stroke and functional outcomes were assessed with logistic and Cox regression analysis.

RESULTS

A total of 346 patients underwent 437 revascularization procedures and the mean follow-up period was 4.0 years. The incidence of perioperative stroke was 6.9%. Being adult at onset (odds ratio [OR], 5.033; 95% confidence interval [CI], 1.447-17.506; P = 0.011) and posterior cerebral artery (PCA) stenosis (OR, 3.364; 95% CI, 1.588-7.265; P = 0.002) before surgery were predictors of perioperative stroke. The annual subsequent stroke rate beyond 30 days after surgery was 1.2%. Subsequent stroke events tended to occur throughout the first 5 years after surgery in adults, whereas in children they mainly occurred within the first 2 years after surgery. Age at onset (OR, 1.025; 95% CI, 1.003-1.048; P = 0.023), ischemic stroke or transient ischemic attack at presentation (OR, 2.703; 95% CI, 1.062-6.875; P = 0.037), and PCA involvement (OR, 2.664; 95% CI, 1.462-4.854; P = 0.001) were associated with higher risk of overall postoperative stroke. PCA involvement (OR, 2.62; 95% CI, 1.33-5.15; P = 0.005), internal carotid artery supraclinoid segment occlusion (OR, 2.76; 95% CI, 1.27-6.03; P = 0.011), and older age at onset (OR, 1.03; 95% CI, 1.01-1.05; P = 0.033) were predictive of unfavorable outcome.

CONCLUSIONS

Patients with ischemic-type MMD at an older age and more severe angiopathy might be at higher risk of recurrent stroke and unfavorable outcome after revascularization.

Restoration of periventricular vasculature after direct bypass for moyamoya disease: intra-individual comparison

BACKGROUND

While periventricular anastomosis, a unique abnormal vasculature in moyamoya disease, has been studied in relation to intracranial hemorrhage, no study has addressed its change after bypass surgery. The authors sought to test whether direct bypass surgery could restore normal periventricular vasculature.

METHODS

Patients who had undergone direct bypass surgery for moyamoya disease at a single institution were eligible for the study. Baseline, postoperative, and follow-up magnetic resonance angiography (MRA) scans were scheduled before surgery, after the first surgery, and 3 to 6 months after contralateral second surgery, respectively. Sliding-thin-slab maximum-intensity-projection coronal MRA images of periventricular anastomoses were scored according to the three subtypes (lenticulostriate, thalamic, and choroidal anastomosis). Baseline and postoperative MRA images were compared to obtain a matched comparison of score changes in the surgical and nonsurgical hemispheres within individuals (intra-individual comparison).

RESULTS

Of 110 patients, 42 were identified for intra-individual comparisons. The periventricular anastomosis score decreased significantly in the surgical hemispheres (median, 2 versus 1; p < 0.001), whereas the score remained unchanged in the nonsurgical hemispheres (median, 2 versus 2; p = 0.57); the score change varied significantly between the surgical and nonsurgical hemispheres (p < 0.001). Of the 104 periventricular-anastomosis-positive hemispheres undergoing surgery, 47 (45.2%) were assessed as negative in the follow-up MRA. Among the subtypes, choroidal anastomosis was most likely to be assessed as negative (79.7% of positive hemispheres).

CONCLUSIONS

Periventricular vasculature can be restored after direct bypass. The likelihood of correction of choroidal anastomosis is a subject requiring further studies.

Intractable Medial Anastomotic Branches from the Lenticulostriate Artery Causing Recurrent Hemorrhages in Moyamoya Disease

BACKGROUND

Although superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis is a beneficial treatment for hemorrhagic moyamoya disease, indeterminate mechanisms can cause rebleeding even after successful bypass surgery. We describe a case with a prominent collateral from the lenticulostriate artery (LSA) causing multiple recurrent hemorrhages after successful STA-MCA anastomosis.

CASE DESCRIPTION

A 49-year-old Japanese woman with moyamoya disease was referred to our institution after suffering intracranial hemorrhage on 2 occasions. Angiography revealed multiple anastomotic vessels branching from a prominent LSA to connect medullary arteries in the periventricular area corresponding to the location of the hemorrhage. She underwent STA-MCA anastomoses and the bypass widely perfused the MCA territory; however, intracranial hemorrhage recurred in the same hemisphere. Angiography revealed sustained dilatation of the medial anastomotic branches from the LSA with de novo pseudoaneurysm, whereas the lateral branches showed shrinkage. Subsequent surgical treatment included direct bypass targeting the medial hemispheric surface in which the medial branches were distributed; marked shrinkage of the branches and disappearance of the aneurysm were obtained without infarct.

CONCLUSIONS

Lenticulostriate anastomotic branches distributed medially to the anterior cerebral artery territory should be given more attention as an intractable cause of hemorrhage after successful STA-MCA anastomosis. Although challenging, direct bypass targeting the area reached by collateral vessels could be considered an alternative treatment strategy for this pathologic condition.

Depression and Catatonia: A Case of Neuropsychiatric Complications of Moyamoya Disease

Moyamoya disease (MMD) is a rare idiopathic cerebrovascular disease most common among the Asian population. Studies have shown that patients with MMD are at increased risk for developing psychiatric complications. We present a patient with hemorrhagic MMD (RNF213 gene mutation) who developed depression and catatonia over time following MMD-related strokes. While no guidelines exist for the management of such an uncommon scenario, it at least requires an interdepartmental approach. Our report highlights the medical complications of untreated MMD and its neuropsychiatric association with depression and catatonia.

Peek through the smoke: a report of moyamoya disease in a 32-year-old female patient presenting with ischaemic stroke

Moyamoya disease is a vasculopathy causing chronic progressive stenosis and occlusion of the large arteries of the circle of Willis that could lead to brain ischaemia. The condition may also present with haemorrhagic strokes. This is a case report of moyamoya disease in a 32-year-old woman presenting with ischaemic stroke. The report describes her inpatient stay and investigations and findings.The report reviews the main aspects of moyamoya disease definition, epidemiology, clinical features, diagnosis, classification and treatment. This case is interesting because her first presentation occurred after 3 months of her second delivery. Whether the different physiological stresses of pregnancy, child birth and puerperium have had some effect in accelerating the pathogenesis of her moyamoya disease remains unknown. ¹.

Encephaloduroarteriosynangiosis for pediatric moyamoya disease: long-term follow-up of 100 cases at a single center

OBJECTIVE The object of this study was to summarize the long-term effect of encephaloduroarteriosynangiosis (EDAS) for the treatment of pediatric moyamoya disease (MMD) and to investigate factors influencing the clinical outcomes of EDAS. METHODS Clinical features, angiographic findings, and clinical outcomes were analyzed among MMD patients younger than 18 years who had been treated with EDAS between 2002 and 2007 at the authors' institution. The Kaplan-Meier method was used to estimate stroke risk after EDAS. Predictors of neurological outcome were assessed. RESULTS One hundred fifteen patients were identified. The mean age at symptom onset was 7.3 ± 4.0 years. The incidence of familial MMD was 11.3%. The female/male ratio was 1:1.16. A total of 232 EDAS procedures were performed, and the incidence of postoperative complications was 3%. Postoperative digital subtraction angiography was performed in 54% of the patients, and about 80% of the hemispheres showed good or excellent results. Neovascularization showed significant correlations with delay time (from symptom onset to first operation), Suzuki stage, and preoperative stroke (all p < 0.05). Clinical follow-up was available in 100 patients with a mean follow-up of 124.4 ± 10.5 months. Ten-year cumulative survival was 96.5% after surgery, and the risk of stroke was 0.33%/person-year. An independent life with no significant disability was reported by 92% of the patients. A good outcome correlated with a low Suzuki stage (p = 0.001). Older children and those without preoperative stroke had better clinical outcomes (p < 0.05). CONCLUSIONS On the basis of long-term follow-up data, the authors concluded that EDAS is a safe and effective treatment for pediatric MMD, can reduce the risk of subsequent neurological events, and can improve quality of life. The risk of ischemia-related complications was higher in younger patients, and older children showed better outcomes. Compensation was greater with more prominent cerebral ischemia. The long-term clinical outcome largely depended on the presence and extent of preoperative stroke.

Direct versus indirect bypasses for adult ischemic-type moyamoya disease: a propensity score–matched analysis

OBJECTIVE

The optimal surgical modality for moyamoya disease (MMD) remains unclear. The aim of this study was to compare the surgical effects of direct bypass (DB) and indirect bypass (IB) in the treatment of adult ischemic-type MMD.

METHODS

Adult patients with ischemic-type MMD who underwent either DB or IB from 2009 to 2015 were identified retrospectively from a prospective database. Patients lost to follow-up or with a follow-up period less than 12 months were excluded. Recurrent stroke events and modified Rankin Scale (mRS) scores at the last follow-up were compared between the 2 surgical groups after 1:1 propensity score matching.

RESULTS

A total of 220 patients were considered, including 143 patients who underwent DB and 77 patients who underwent IB. After propensity score matching, 70 pairs were obtained. The median follow-up period was 40.5 months (range 14–75 months) in the DB group and 31.5 months (range 14–71 months) in the IB group (p = 0.004). Kaplan-Meier analysis showed that patients who received DB had a longer stroke-free time (mean 72.1 months) compared with patients who received IB (mean 61.0 months) (p = 0.045). Good neurological status (mRS score ≤ 2) was achieved in 64 patients in the DB group (91.4%) and 66 patients in the IB group (94.3%), but there was no significant difference (p = 0.512).

CONCLUSIONS

Although neurological function outcome was not determined by the surgical modality, DB is more effective in preventing recurrent ischemic strokes than IB for adult ischemic-type MMD.

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.

Clinical features, course, and outcomes of a UK cohort of pediatric moyamoya

Objective

To describe characteristics and course of a large UK cohort of children with moyamoya from multiple centers and examine prognostic predictors.

Methods

Retrospective review of case notes/radiology, with use of logistic regression to explore predictors of outcome.

Results

Eighty-eight children (median presentation age 5.1 years) were included. Thirty-six presented with arterial ischemic stroke (AIS) and 29 with TIA. Eighty had bilateral and 8 unilateral carotid circulation disease; 29 patients had posterior circulation involvement. Acute infarction was present in 36/176 hemispheres and chronic infarction in 86/176 hemispheres at the index presentation. Sixty-two of 82 with symptomatic presentation had at least one clinical recurrence. Fifty-five patients were treated surgically, with 37 experiencing fewer recurrences after surgery. Outcome was categorized as good using the Recovery and Recurrence Questionnaire in 39/85 patients. On multivariable analysis, presentation with TIA (odds ratio [OR] 0.09, 95% confidence interval [CI] 0.02–0.35), headache (OR 0.10, 95% CI 0.02–0.58), or no symptoms (OR 0.08, 95% CI 0.01–0.68) was less likely to predict poor outcome than AIS presentation. Posterior circulation involvement predicted poor outcome (OR 4.22, 95% CI 1.23–15.53). Surgical revascularization was not a significant predictor of outcome.

Conclusions

Moyamoya is associated with multiple recurrences, progressive arteriopathy, and poor outcome in half of patients, especially with AIS presentation and posterior circulation involvement. Recurrent AIS is rare after surgery. Surgery was not a determinant of overall outcome, likely reflecting surgical case selection and presentation clinical status.

The Role of RNF213 4810G>A and 4950G>A Variants in Patients with Moyamoya Disease in Korea

Although a founder variant of RNF213 4810G>A is a major genetic risk factor for moyamoya disease (MMD) in East Asians, the frequency and disease susceptibility of RNF213 variants remain largely unknown. This study investigated the mutation analysis of RNF213 (4448, 4810, 4863, and 4950) between Korean MMD and healthy controls. We performed a polymerase chain reaction-restriction fragment length polymorphism analysis. To identify the association between RNF213 gene polymorphisms and MMD disease, we performed statistical analyses such as multivariable logistic regression and Fisher’s exact test. Genetic data from 117 MMD patients were analyzed and compared with 253 healthy controls. We assessed and compared single nucleotide polymorphisms of RNF213 (4448, 4810, 4863, and 4950) between MMD and control groups. We performed genome-wide association studies to investigate the genetic pathophysiology of MMD. Among the RNF213 variants (4448G>A, 4810G>A, 4863G>A, and 4950G>A), RNF213 4810G>A and 4950G>A variants were more frequent in MMD patients. In a subgroup analysis, the RNF213 4810G>A was more frequent in moyamoya disease, and the comparison with GG+AA genotype was also significantly different in moyamoya patients. These results confirm that RNF213 4810G>A and RNF213 4950G>A were more frequent in MMD patients. We have confirmed that RNF213 4810G>A and 4950G>A are strongly associated with Korean MMD in children and adults as well as for the ischemic and hemorrhagic types.

Bypass surgery versus medical treatment for symptomatic moyamoya disease in adults

OBJECTIVE

In this study the authors evaluated whether extracranial-intracranial bypass surgery can prevent stroke occurrence and decrease mortality in adult patients with symptomatic moyamoya disease (MMD).

METHODS

The medical records of 249 consecutive adult patients with symptomatic MMD that was confirmed by digital subtraction angiography between 2002 and 2011 at 8 institutions were retrospectively reviewed. The study outcomes of stroke recurrence as a primary event and death during the 6-year follow-up and perioperative complications within 30 days as secondary events were compared between the bypass and medical treatment groups.

RESULTS

The bypass group comprised 158 (63.5%) patients, and the medical treatment group comprised 91 (36.5%) patients. For 249 adult patients with MMD, bypass surgery showed an HR of 0.48 (95% CI 0.27–0.86, p = 0.014) for stroke recurrence calculated by Cox regression analysis. However, for the 153 patients with ischemic MMD, the HR of bypass surgery for stroke recurrence was 1.07 (95% CI 0.43–2.66, p = 0.887). For the 96 patients with hemorrhagic MMD, the multivariable adjusted HR of bypass surgery for stroke recurrence was 0.18 (95% CI 0.06–0.49, p = 0.001). For the treatment modality, indirect bypass and direct bypass (or combined bypass) did not show any significant difference for stroke recurrence, perioperative stroke, or mortality (log rank; p = 0.524, p = 0.828, and p = 0.616, respectively).

CONCLUSIONS

During the treatment of symptomatic MMD in adults, bypass surgery reduces stroke recurrence for the hemorrhagic type, but it does not do so for the ischemic type. The best choice of bypass methods in adult patients with MMD is uncertain. In adult ischemic MMD, a prospective randomized study to evaluate the effectiveness and safety of bypass surgery to prevent recurrent stroke is necessary.

Integrated Analysis of LncRNA-mRNA Co-Expression Profiles in Patients with Moyamoya Disease

Moyamoya disease (MMD) is an idiopathic disease associated with recurrent stroke. However, the pathogenesis of MMD remains unknown. Therefore, we performed long noncoding RNA (lncRNA) and messenger RNA (mRNA) expression profiles in blood samples from MMD patients (N = 15) and healthy controls (N = 10). A total of 880 differentially expressed lncRNAs (3649 probes) and 2624 differentially expressed mRNAs (2880 probes) were obtained from the microarrays of MMD patients and healthy controls (P < 0.05; Fold Change >2.0). Gene ontology (GO) and pathway analyses showed that upregulated mRNAs were enriched for inflammatory response, Toll-like receptor signaling pathway, chemokine signaling pathway and mitogen-activated protein kinase (MAPK) signaling pathway among others, while the downregulated mRNAs were enriched for neurological system process, digestion, drug metabolism, retinol metabolism and others. Our results showed that the integrated analysis of lncRNA-mRNA co-expression networks were linked to inflammatory response, Toll-like signaling pathway, cytokine-cytokine receptor interaction and MAPK signaling pathway. These findings may elucidate the pathogenesis of MMD, and the differentially expressed genes could provide clues to find key components in the MMD pathway.

Ultrasonographic Changes after Indirect Revascularization Surgery in Pediatric Patients with Moyamoya Disease

The marked cerebral hypoperfusion of moyamoya disease (MMD) can be treated with encephaloduroarteriosynangiosis (EDAS), an indirect revascularization surgery. Collateral establishment after the surgery is a gradual process; thus, easy access to serial assessment is of great importance. We prospectively recruited 15 pediatric moyamoya patients who underwent EDAS surgeries on a total of 19 hemispheres. Ultrasonography of extracranial and intracranial arteries was performed pre-operatively and post-operatively at 1, 3 and 6 mo. Among the extracranial arteries, the superficial temporal artery had the most pronounced increase in flow velocity and decrease in flow resistance from 1 mo post-surgery (p < 0.01). Among the large intracranial arteries, a significant increase in peak systolic velocity was observed in the anterior cerebral artery from 3 mo post-surgery (p < 0.05). These findings indicate significant hemodynamic changes on ultrasonography in pediatric moyamoya patients after indirect revascularization surgery.

[Clinical manifestations of the onset and diagnostic problems in children with moyamoya disease]

Moyamoya disease in children is a rarely diagnosed entity. Frequent headache is the first symptom of the disease. Headache associated with moya-moya disease (HAMD) is a separated entity reported in the literature. Variants of onset, a spectrum of primary diagnoses and diagnosis verification rate of moyamoya disease in 7 children are presented. A clinical case of moya-moya disease in a 9-year boy, who was primarily diagnosed with migraine with aura, is reported. The results presented by the authors as well as literature data indicate the necessity of using magnetic-resonance angiography in children with headache attacks and focal neurologic symptoms to identify this progressive vascular pathology and timely recommend a surgical treatment.

A Case of Homocystinuria Misdiagnosed as Moyamoya Disease: A Case Report

Introduction

Homocystinuria is a hereditary disease caused by a defect in the enzymes involved in metabolizing methionine. Homocystinuria can influence many systems and may be mistaken for other diseases, including Moyamoya disease. Here, we report the case of a 10-year-old male patient with a diagnosis of Moyamoya disease who had been monitored for that for an extended period. The patient’s diagnosis was changed to homocystinuria as a result of lens subluxation and cataract findings.

Case Presentation

A 10-year-old male patient presented with vomiting, headache, lethargy, muscular weakness, and eye redness. The patient was mentally retarded, his right pupil was hyperemic, and he had muscle weakness on his left side. In addition, his blood pressure was high. The patient’s history included a diagnosis of Moyamoya. A neck and cranial computed tomography (CT) angiography showed no flow bilaterally past the bifurcation of the carotid artery. The patient’s bilateral internal carotid arteries were determined to be occluded. It was considered that his eye findings could be compatible with a metabolic disease. On metabolic screening, the patient’s homocysteine level was very high. In addition, a heterozygous A1298C mutation was identified in MTHFR. Therefore, the patient was started on a diet free from homocysteine and methionine. In addition, his treatment regimen included vitamins B12 and B6. With these treatments, the patient’s complications regressed.

Conclusions

In cases of unusual vascular lesions, metabolic diseases must be considered. In homocystinuria, early diagnosis and treatment are important. Blood homocysteine levels can be returned to normal, and some complications can be prevented.

Long term outcome and predictors of ischemic stroke recurrence in adult moyamoya disease

OBJECTIVE

We sought to identify the clinical outcome and predictors for ischemic stroke recurrence in adults with symptomatic moyamoya disease (MMD).

METHODS

We analyzed 104 adult MMD patients with ischemic stroke or TIA registered at our institution. All patients underwent digital subtraction angiography and single photon emission computed tomography to measure disease severity and cerebral vascular reserve (CVR). A Cox regression model was used to identify predictors of recurrent ischemic stroke.

RESULTS

Fifty-nine patients were non-surgically treated and 45 patients were surgically treated. In the non-surgical group, the Kaplan-Meier estimate of ischemic stroke recurrence was 1.6% in the first year and 11.8% in the 5th year. Hypertension (hazard ratio [HR]=0.07, 95% confidence interval [CI] 0.01-0.99), diabetes (HR=35.16, 95% CI 2.61-474.16), presence of steno-occlusive lesion in posterior cerebral arteries (HR=17.53, 95% CI 2.02-152.43), and extended or global decreased CVR (HR=13.62, 95% CI 1.55-119.84) were independent predictors of recurrence. In the surgical group, the Kaplan-Meier estimate of ischemic stroke recurrence was 24.4% in the first year and 24.4% in the 5th year. Half of the recurred patients experienced recurrent ischemic strokes postoperatively. Diabetes was the only predictor of recurrent ischemic stroke (HR=6.17, 95% CI 1.31-29.14).

CONCLUSIONS

In non-surgically treated MMD, PCA stenosis and CVR were identified as predictors of ischemic stroke recurrence. Diabetes was an independent predictor of recurrent ischemic stroke in both non-surgical and surgically treated MMD groups.

Moyamoya angiopathy - Is there a Western phenotype?

Moyamoya disease (MMD) is a chronic cerebrovascular disease involving progressive bilateral stenosis of the intracranial segments of the internal carotid arteries. It results in the development of a rich, but friable collateral supply, prone to rupture. The disease is well described in Japanese literature and was originally thought to be a predozminantly Eastern disease. However, the recent literature describes a Western phenotype that may present with a different clinical course. This review aims to describe the variations in the epidemiology of the MMD between Eastern and Western populations, the possible reasons for them and highlight their implications for clinical practise and future research.

Inherited neurovascular diseases affecting cerebral blood vessels and smooth muscle

Neurovascular diseases are among the leading causes of mortality and permanent disability due to stroke, aneurysm, and other cardiovascular complications. Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and Marfan syndrome are two neurovascular disorders that affect smooth muscle cells through accumulation of granule and osmiophilic materials and defective elastic fiber formations respectively. Moyamoya disease, hereditary hemorrhagic telangiectasia (HHT), microcephalic osteodysplastic primordial dwarfism type II (MOPD II), and Fabry's disease are disorders that affect the endothelium cells of blood vessels through occlusion or abnormal development. While much research has been done on mapping out mutations in these diseases, the exact mechanisms are still largely unknown. This paper briefly introduces the pathogenesis, genetics, clinical symptoms, and current methods of treatment of the diseases in the hope that it can help us better understand the mechanism of these diseases and work on ways to develop better diagnosis and treatment.

Single Nucleotide Polymorphism in Patients with Moyamoya Disease

Moyamoya disease (MMD) is a chronic, progressive, cerebrovascular occlusive disorder that displays various clinical features and results in cerebral infarct or hemorrhagic stroke. Specific genes associated with the disease have not yet been identified, making identification of at-risk patients difficult before clinical manifestation. Familial MMD is not uncommon, with as many as 15% of MMD patients having a family history of the disease, suggesting a genetic etiology. Studies of single nucleotide polymorphisms (SNPs) in MMD have mostly focused on mechanical stress on vessels, endothelium, and the relationship to atherosclerosis. In this review, we discuss SNPs studies targeting the genetic etiology of MMD. Genetic analyses in familial MMD and genome-wide association studies represent promising strategies for elucidating the pathophysiology of this condition. This review also discusses future research directions, not only to offer new insights into the origin of MMD, but also to enhance our understanding of the genetic aspects of MMD. There have been several SNP studies of MMD. Current SNP studies suggest a genetic contribution to MMD, but further reliable and replicable data are needed. A large cohort or family-based design would be important. Modern SNP studies of MMD depend on novel genetic, experimental, and database methods that will hopefully hasten the arrival of a consensus conclusion.

Foramen spinosum and middle meningeal artery in moyamoya disease: Preliminary results of a pilot study

OBJECT

This study investigated whether the size of the middle cranial fossa foramina reflects the severity of moyamoya disease (MMD).

METHODS

It compared 20 adult patients managed without surgical revascularization with 2 age- and sex-matched controls. MR angiography scores were assigned by the severity of occlusive changes of the internal carotid artery, the middle cerebral artery, the anterior and the posterior cerebral arteries and the signals of the distal branches of these arteries. These scores were stratified into MR angiography grades (Houkin's grade: 1-4). The relationships between the Houkin's grade and the size of the foramen spinosum (FS), foramen ovale, carotid canal and middle meningeal artery (MMA) were evaluated.

RESULTS

Simple regression analysis showed the correlation between the Houkin's grade and the bilateral FS (right, r = 0.56, p = 0.010; left, r = 0.46, p = 0.044) and MMA (right, r = 0.89, p = 0.0050; left, r = 0.47, p = 0.036). It also showed the correlation between the FS and MMA (right, r = 0.53, p = 0.018; left, r = 0.55, p = 0.013). There were no significant differences between the Houkin's grade, the size of the carotid canal and the foramen ovale.

CONCLUSIONS

The larger FS and MMA on brain CT, which might be performed for patients suspected of intracranial lesions, could aid the diagnosis of MMD.