Contralateral progression and its risk factor in surgically treated unilateral adult moyamoya disease with a review of pertinent literature

RNF213 Polymorphisms in Intracranial Artery Dissection

The ring finger protein 213 gene (RNF213) is involved in several vascular diseases, both intracranial and systemic ones. Some variants are common in the Asian population and are reported as a risk factor for moyamoya disease, intracranial stenosis and intracranial aneurysms. Among intracranial vascular diseases, both moyamoya disease and intracranial artery dissection are more prevalent in the Asian population. We performed a systematic review of the literature, aiming to assess the rate of RNF213 variants in patients with spontaneous intracranial dissections. Four papers were identified, providing data on 53 patients with intracranial artery dissection. The rate of RNF213 variants is 10/53 (18.9%) and it increases to 10/29 (34.5%), excluding patients with vertebral artery dissection. All patients had the RNF213 p.Arg4810Lys variant. RNF213 variants seems to be involved in intracranial dissections in Asian cohorts. The small number of patients, the inclusion of only patients of Asian descent and the small but non-negligible coexistence with moyamoya disease familiarity might be limiting factors, requiring further studies to confirm these preliminary findings and the embryological interpretation.

Progression of initially unilateral Moyamoya angiopathy in Caucasian Europeans

BACKGROUND

Moyamoya angiopathy (MMA) is a rare cause of stroke in Caucasians, but it is much more frequent in East Asia. Since 2021, diagnostic criteria not only comprise bilateral, but also unilateral MMA. Hitherto, progression of unilateral MMA has predominantly been described in East Asians. Our study aimed to analyze the occurrence and characteristics of progression of initially unilateral MMA in Caucasian Europeans.

METHODS

By retrospective analysis of medical records of 200 European Caucasians with MMA, admitted to our German center between 2010 and 2022, cases of unilateral MMA and its progression, i.e. progressive ipsi- or novel contralateral arterial stenosis, during follow-up were identified. Kruskal Wallis Test and Fisher's Exact Test were used to identify statistically significant differences between progressive and stable patients concerning demographic, clinical, laboratory, and radiographic features.

RESULTS

Our cohort comprised 63 patients with initially unilateral MMA. Fourteen (22.2%) had an ipsi- (n = 3, 21.4%) or contralateral (n = 11, 78.6%) progression. Mean age of patients with progressive MMA at symptom onset was 32 ± 14.1 years. The ratio of women to men in this subgroup was 2.5:1. Mean follow-up period was 5.4 ± 3.7 years, mean age at progression was 39.9 ± 12.7 years. Mean time interval between penultimate follow-up and progression was 4.8 ± 4.5 years. Patients with progression showed affection of the posterior cerebral artery (p = 0.009) and suffered from vertigo (p = 0.009) significantly more often.

CONCLUSION

Unilateral MMA progresses in a substantial proportion in European Caucasians. Long-term follow-up is required due to potential late progression with consecutive symptoms and the need for bypass surgery.

Potential predictors for progression of moyamoya disease: A systematic review and meta-analysis

Background

The progress of Moyamoya disease (MMD) is often accompanied by the occurrence of new ischemia or hemorrhagic events, which was difficult to predict. This systematic review and meta-analysis aimed to identify predictors for progression in MMD patients.

Methods

We searched PubMed, Web of Science, Cochrane Library, and Embase databases up to December 10th, 2022 for randomized controlled trials, case-control studies, or cohort studies reporting predictors of disease progression in MMD patients. The results of each predictor were pooled by meta-analysis and further analyzed by subgroup analysis for predictors of unilateral to bilateral progression of MMD.

Results

A total of 842 patients from 12 studies were included. The estimated pooled means indicated lower age (standard mean difference [SMD]: -0.29, 95% confidence interval [CI]: -0.55 to -0.03; P = 0.03), family history (odds ratio [OR] 3.97, 95% CI: 1.96 to 8.03; P < 0.001) and contralateral abnormality (OR 3.95, 95% CI: 1.10 to 14.20; P = 0.04) were associated with progression in MMD patients. Subgroup analyses indicated that the same three factors were associated with the progression of unilateral to bilateral MMD.

Conclusions

This meta-analysis revealed that lower age, family history and contralateral abnormality were associated with progression in MMD patients. The same three factors are associated with the progression of unilateral to bilateral MMD. Further studies are needed to validate our results.

RNF213 R4810K Variant in Suspected Unilateral Moyamoya Disease Predicts Contralateral Progression

Background Early-stage unilateral moyamoya disease (MMD) is difficult to discriminate from isolated intracranial atherosclerotic stenosis, and identification of contralateral progression may aid in the diagnosis of MMD. The RNF213 (ring finger protein 213) R4810K variant is a strong genetic susceptibility factor for MMD; however, the role of contralateral progression in unilateral MMD is unknown. Methods and Results Patients who had undergone RNF213 R4810K genotyping with suspected unilateral MMD between January 2017 and August 2021 from 2 tertiary university hospitals were retrospectively reviewed. We compared the clinical features and radiographic outcomes of patients with and without this variant. The risk factors of contralateral progression in patients with suspected unilateral MMD were evaluated. The RNF213 R4810K variant was observed in 72 of 123 patients with suspected unilateral MMD, all of which were heterozygous. The allele frequency of the R4810K variant was significantly higher in the suspected unilateral MMD group compared with the historical control group (29.3% versus 1.2%; P<0.0001). Family history of MMD was significantly more common in patients with the variant than in those without (17% versus 4%; P=0.003). Eleven of 72 patients with the variant developed contralateral progression, whereas only 1 of 51 patients without the variant developed contralateral progression during a median follow-up period of 28 months (log-rank test; P=0.03). The presence of the RNF213 R4810K variant significantly correlated with contralateral progression (adjusted odds ratio, 6.39 [95% CI, 1.11-36.63]; P=0.04). Conclusions Contralateral progression is more likely to occur in patients with suspected unilateral MMD with the RNF213 R4810K variant than in those without the variant. However, because our study used a small sample size, this finding should be carefully interpreted and requires further studies with more patients and longer follow-up periods.

Asymptomatic Moyamoya Disease in a North American Adult Cohort

OBJECTIVE

The natural history of asymptomatic adult moyamoya disease (MMD) is unclear, and the benefit of treatment remains controversial. This study aimed to investigate the natural history of asymptomatic MMD in a North American cohort and to evaluate risk factors associated with and the effects of treatment on disease progression.

METHODS

Medical records from 3 institutions of consecutive adult patients with MMD diagnosed between 1984 and 2018 were retrospectively reviewed. Patients with unilateral or bilateral asymptomatic MMD were evaluated for subsequent development of infarction or hemorrhage. Multivariate Cox proportional hazards regression assessed risk factors associated with infarction or hemorrhage, adjusting for age, sex, race, initial Suzuki grade, hypertension, hyperlipidemia, diabetes, obesity, presence of aneurysms, smoking status, aspirin, and statin use at diagnosis.

RESULTS

We identified 106 hemispheres with asymptomatic MMD in 97 patients with mean 5.1 years (interquartile range, 1.0-7.9 years) of follow-up. Of 106 hemispheres, 59 were treated medically, and 47 were treated with revascularization with direct or indirect bypasses. The medical and surgical cohorts had a 1.9% and 1.3% annual rate of radiographic infarction or hemorrhage per hemisphere, respectively. Cox regression for radiographic events, including early postoperative events, showed no significant difference between the treatment groups (adjusted hazard ratio 0.34 [95% confidence interval 0.05-2.5]).

CONCLUSIONS

We found an overall 1.7% annual rate of radiographic infarction or hemorrhage in asymptomatic MMD hemispheres. Although we did not find a benefit to surgical treatment within the study period, asymptomatic patients with expected long-term survival may benefit from surgery given the sustained long-term benefits after surgery despite an initial postoperative risk.

Genetic and nongenetic factors for contralateral progression of unilateral moyamoya disease: the first report from the SUPRA Japan Study Group

OBJECTIVE

Although many studies have analyzed risk factors for contralateral progression in unilateral moyamoya disease, they have not been fully elucidated. The aim of this study was to examine whether genetic factors as well as nongenetic factors are involved in the contralateral progression.

METHODS

The authors performed a multicenter cohort study in which 93 cases with unilateral moyamoya disease were retrospectively reviewed. The demographic features, RNF213 R4810K mutation, lifestyle factors such as smoking and drinking, past medical history, and angiographic findings were analyzed. A Cox proportional hazards model was used to find risk factors for contralateral progression.

RESULTS

Contralateral progression was observed in 24.7% of cases during a mean follow-up period of 72.2 months. Clinical characteristics were not significantly different between 67 patients with the R4810K mutation and those without it. Cox regression analysis showed that the R4810K mutation (hazard ratio [HR] 4.64, p = 0.044), childhood onset (HR 7.21, p < 0.001), male sex (HR 2.85, p = 0.023), and daily alcohol drinking (HR 4.25, p = 0.034) were independent risk factors for contralateral progression.

CONCLUSIONS

These results indicate that both genetic and nongenetic factors are associated with contralateral progression of unilateral moyamoya disease. The findings would serve to help us better understand the pathophysiology of moyamoya disease and to manage patients more appropriately.

Modifiable Risk Factors Associated With Moyamoya Disease: A Case-Control Study

BACKGROUND AND PURPOSE

The cause of moyamoya disease (MMD) remains unknown. We aimed to investigate the association between modifiable risk factors and MMD in a prospective, case-control study.

METHODS

Clinical and laboratory characteristics were evaluated in consecutively recruited adult patients with MMD and age-matched healthy control individuals. The potential risk factors for MMD were estimated by logistic regression analysis.

RESULTS

Our prospective study included 138 adult patients and 138 healthy control subjects. Logistic regression analyses showed that increased body mass index (odds ratio [OR], 1.121 [95% CI, 1.018-1.234]; P=0.020) and homocysteine (OR, 1.201 [95% CI, 1.081-1.334]; P=0.001) were associated with higher risk of MMD. Whereas increased albumin (OR, 1.043 [95% CI, 1.004-1.082]; P=0.028) and high-density lipoprotein cholesterol (OR, 1.043 [95% CI, 1.004-1.082]; P=0.028) were correlated with a lower risk of MMD. Furthermore, homocysteine (OR, 1.070 [95% CI, 1.010-1.134]; P=0.023) was significantly related to unilateral lesions.

CONCLUSIONS

Increased body mass index and homocysteine were associated with a higher risk of MMD. In contrast, increased albumin and high-density lipoprotein cholesterol were correlated with a lower risk of MMD. Furthermore, increased homocysteine was related to a higher prevalence of unilateral MMD. More attention should be paid to the modifiable risk factors of MMD, as these might help us finding its cause and new therapeutic regimen. Registration: URL: http://www.chictr.org. Unique identifier: ChiCTR2000031412.

Surgery for Moyamoya Disease in Children

Moyamoya disease is a chronic progressive cerebrovascular occlusive disease of the terminal portion of the internal carotid arteries associated with an acquired abnormal vascular network at the base of the brain, often leading to ischemic or hemorrhagic stroke. Moyamoya disease is a relatively common cause of pediatric stroke with a specific racial and well-identified clinical and imaging phenotype. Moyamoya disease is more prevalent in East Asian countries compared with other geographic regions with a higher incidence of familial cases and clinically more aggressive form. Moyamoya disease is one of the few causes of stroke that is amenable to effective surgical revascularization treatment. There are various surgical options available for revascularization, including the direct, indirect, or combined bypass techniques, each with variable responses. However, due to the heterogeneity of the diseases, different clinical course, geographical variables associated with the disease, and availability of a wide variety of surgical revascularization procedures, optimal selection of a surgical candidate and the surgical technique becomes challenging, particularly in the pediatric population. This brief review presents pertinent literature of clinical options for the diagnosis and surgical treatment of moyamoya disease in children.

Association of Hyperthyroidism and Thyroid Autoantibodies with Moyamoya Disease and Its Stroke Event: A Population-based Case-control Study and Meta-analysis

The aim of this study was to investigate the specific thyroid condition and thyroid autoantibodies in adult moyamoya disease (MMD) according to clinical presentation (ischemia vs. hemorrhage stroke). In addition, a meta-analysis was performed to reveal the association between adult MMD and elevated thyroid function, or autoantibodies. Prospectively collected data on 169 consecutive patients with MMD at a single institution were analyzed. Community-based controls matched for age and sex were selected for comparison. Penalized multinomial logistic regression analysis was used for factors affecting stroke. For meta-analysis, heterogeneity was evaluated by using the I² test. If I² < 50%, a fixed effect model was used. Fifty-four cases (32.0%) presented with ischemic stroke and 37 cases (21.9%) with hemorrhage stroke. Hyperthyroidism had a marginally increased risk of MMD with ischemic stroke with reference value of MMD without stroke [odds ratio (OR), 2.53; P = 0.055]. Anti-thyroperoxidase antibody (TPOAb) increased the risk of MMD presenting with ischemic stroke significantly (OR, 2.99; P = 0.020). A meta-analysis revealed that adult MMD was significantly associated with elevated autoantibodies (OR, 7.663; P = 0.002) and hyperthyroidism (OR, 10.936; P < 0.001). Elevated TPOAb and hyperthyroidism may play important roles in adult MMD with ischemic stroke. Studies focusing on targeted hyperthyroidism and thyroid autoantibodies are necessary in treating adult MMD patients in the future.

Meta-analysis of the surgical outcomes of symptomatic moyamoya disease in adults

OBJECTIVE The purpose of this study was to evaluate treatment outcomes of future stroke prevention, perioperative complications, and angiographic revascularization in adults with symptomatic moyamoya disease (MMD) according to treatment modalities and surgical techniques. METHODS A systemic literature review was performed based on searches of the PubMed, Embase, and Cochrane Central databases. A fixed-effects model was used in cases of heterogeneity less than 50%. Publication bias was determined by Begg's funnel plot, Egger's test of the intercept, and the Begg and Mazumdar rank correlation test. RESULTS Eleven articles were included in the meta-analysis. Bypass surgery significantly decreased the future stroke events compared with conservative treatments in adult MMD (odds ratio [OR] 0.301, p < 0.001). Direct bypass showed better future stroke prevention than indirect bypass (OR 0.494, p = 0.028). There was no meaningful difference in perioperative complications between direct and indirect bypass (OR 0.665, p = 0.176). Direct bypass was associated with better angiographic outcomes than indirect bypass (OR 6.832, p < 0.001). CONCLUSIONS Bypass surgery can be effective in preventing future stoke events in adults with MMD. Direct bypass seems to provide better risk reduction with respect to stroke than indirect bypass in these patients.

Evaluation of Encephaloduroarteriosynangiosis Efficacy Using Probabilistic Independent Component Analysis Applied to Dynamic Susceptibility Contrast Perfusion MRI

BACKGROUND AND PURPOSE

Indirect cerebral revascularization has been successfully used for treatment in Moyamoya disease and symptomatic intracranial atherosclerosis. While angiographic neovascularization has been demonstrated after surgery, measurements of local tissue perfusion are scarce and may not reflect the reported successful clinical outcomes. We investigated probabilistic independent component analysis and conventional perfusion parameters from DSC-MR imaging to measure postsurgical changes in tissue perfusion.

MATERIALS AND METHODS

In this prospective study, 13 patients underwent unilateral indirect cerebral revascularization and DSC-MR imaging before and after surgery. Conventional perfusion parameters (relative cerebral blood volume, relative cerebral blood flow, and TTP) and probabilistic independent components that reflect the relative contributions of DSC signals consistent with arterial, capillary, and venous hemodynamics were calculated and examined for significant changes after surgery. Results were compared with postsurgical DSA studies to determine whether changes in tissue perfusion were due to postsurgical neovascularization.

RESULTS

Before surgery, tissue within the affected hemisphere demonstrated a high probability for hemodynamics consistent with venous flow and a low probability for hemodynamics consistent with arterial flow, whereas the contralateral control hemisphere demonstrated the reverse. Consistent with symptomatic improvement, the probability for venous hemodynamics within the affected hemisphere decreased with time after surgery (P = .002). No other perfusion parameters demonstrated this association. Postsurgical DSA revealed an association between an increased preoperative venous probability in the symptomatic hemisphere and neovascularization after surgery.

CONCLUSIONS

Probabilistic independent component analysis yielded sensitive measurements of changes in local tissue perfusion that may be associated with newly formed vasculature after indirect cerebral revascularization surgery.

Moyamoya Disease with Coexistent Hypertriglyceridemia in Pediatric Patient

Moyamoya disease is a rare chronic and progressive cerebrovascular disease of the arteries of the circle of Willis that can affect children and adults. It has been associated with multiple diseases, including immunologic, like Graves' disease, diabetes mellitus, and SLE. Hyperlipidemia has been recognized in patients with Moyamoya disease with an incidence of 27-37%. However, no case in pediatric patients has been reported of the coexistence of Moyamoya disease and hyperlipidemia. Here we present a case of a 9-year-old female diagnosed with Moyamoya disease after a stroke with incidental finding of familial hypercholesterolemia. This finding will make our patient a very unique case, since there has not been any reporting of Moyamoya disease and hypercholesterolemia association.

A Recent Update of Clinical and Research Topics Concerning Adult Moyamoya Disease

A better understanding of moyamoya disease (MMD), such as natural clinical course, surgical outcomes and research, has been obtained. This review article focuses on an giving an update for adult MMD in the Korean population. In this paper, we mainly discuss the results of our domestic investigations including meta-analysis, and related subjects from other countries.

Nonatheroscleotic Isolated Middle Cerebral Artery Disease May Be Early Manifestation of Moyamoya Disease

Background and Purpose—

Middle cerebral artery steno-occlusive disease (MCAD) is not an uncommon cause of ischemic stroke in young Asians. Aside from atherosclerosis, the pathogenesis of MCAD include various nonatherosclerotic vasculopathies, most of which are yet to be defined. This study investigated the pathogenesis of symptomatic isolated MCAD in young Asian patients using high-resolution magnetic resonance imaging (HR-MRI) and mutation analysis of RNF213 .

Methods—

Patients aged <60 years with stroke or transient ischemic attack caused by MCAD were prospectively enrolled. Patients with a confirmed diagnosis of moyamoya disease, dissection, and vasculitis; with significant steno-occlusion in cerebral arteries other than the MCA; or with high-risk cardioembolic source were excluded. Using high-resolution MRI, patients were classified into an atherosclerosis group and a nonatherosclerosis group.

Results—

Eighty-one patients were enrolled, 45 (56.6%) in the atherosclerosis and 36 (44.4%) in the nonatherosclerosis group. The nonatherosclerosis group was significantly younger ( P =0.013), had a smaller number of vascular risk factors ( P =0.001), showed a lower homocysteine level ( P <0.001), thinner intima-media thickness ( P =0.006), and had more frequent heterozygotes at RNF213 ( P =0.045) than the atherosclerosis group. Diffusion-weighted image lesion pattern showed no significant differences in assumed stroke mechanisms between the 2 groups.

Conclusions—

Nonatherosclerotic pathogenesis are common in young Asians with symptomatic isolated MCAD. Clinical findings, high-resolution MRI features, and results of RNF213 mutation analysis suggest that moyamoya disease is responsible etiologically for a significant portion of nonatherosclerotic lesions. Symptomatic isolated MCAD may be an early manifestation of moyamoya disease in young Asian adults.

Moyamoya Disease: Treatment and Outcomes

Although the pathogenesis of moyamoya disease (MMD) has not been fully elucidated, the effectiveness of surgical revascularization in preventing stroke has been addressed by many studies. The main mechanism of surgical revascularization is augmenting the intracranial blood flow using an external carotid system by either direct bypass or pial synangiosis. This can improve resting cerebral blood flow as well as vascular reserve capacity. For direct revascularization, the superficial temporal artery is used as the donor artery in most cases, although the occipital artery may be used in limited cases. Usually, the cortical branch of the middle cerebral artery is selected as the recipient of direct anastomosis. As for indirect revascularization, various techniques using different kinds of connective tissues have been introduced. In some cases, reinforcing the anterior cerebral artery and the posterior cerebral artery territories can be considered. The effectiveness of surgical revascularization for preventing ischemic stroke had been generally accepted by many studies. However, for preventing hemorrhagic stroke, new evidence has been added by a recent randomized controlled trial. The incidence of peri-operative complications such as stroke and hyperperfusion syndrome seems to be high due to the nature of the disease and technical demands for treatment. Preventing and adequately managing these complications are essential for ensuring the benefits of surgery.

Moyamoya disease and syndromes: from genetics to clinical management

Moyamoya angiopathy is characterized by a progressive stenosis of the terminal portion of the internal carotid arteries and the development of a network of abnormal collateral vessels. This chronic cerebral angiopathy is observed in children and adults. It mainly leads to brain ischemic events in children, and to ischemic and hemorrhagic events in adults. This is a rare condition, with a marked prevalence gradient between Asian countries and Western countries. Two main nosological entities are identified. On the one hand, moyamoya disease corresponds to isolated moyamoya angiopathy, defined as being “idiopathic” according to the Guidelines of the Research Committee on the Pathology and Treatment of Spontaneous Occlusion of the Circle of Willis. This entity is probably multifactorial and polygenic in most patients. On the other hand, moyamoya syndrome is a moyamoya angiopathy associated with an underlying condition and forms a very heterogeneous group with various clinical presentations, various modes of inheritance, and a variable penetrance of the cerebrovascular phenotype. Diagnostic and evaluation techniques rely on magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) conventional angiography, and cerebral hemodynamics measurements. Revascularization surgery can be indicated, with several techniques. Characteristics of genetic moyamoya syndromes are presented, with a focus on recently reported mutations in BRCC3/MTCP1 and GUCY1A3 genes. Identification of the genes involved in moyamoya disease and several monogenic moyamoya syndromes unraveled different pathways involved in the development of this angiopathy. Studying genes and pathways involved in monogenic moyamoya syndromes may help to give insights into pathophysiological models and discover potential candidates for medical treatment strategies.

Unstable moyamoya disease: clinical features and impact on perioperative ischemic complications

OBJECT

Unstable moyamoya disease, reasonably defined as cases exhibiting either rapid disease progression or repeated ischemic stroke, represents a challenge in the treatment of moyamoya disease. Despite its overall efficacy, direct bypass for such unstable disease remains controversial in terms of safety. This study aims to reveal factors associated with unstable disease and to assess its impact on postoperative silent or symptomatic ischemic lesions.

METHODS

This retrospective cohort study included both pediatric and adult patients with moyamoya disease who had undergone 140 consecutive direct bypass procedures at Kyoto University Hospital. “Unstable moyamoya disease” was defined as either the rapid progression of a steno-occlusive lesion or repeat ischemic stroke, either occurring within 6 months of surgery. The extent of progression was determined through a comparison of the findings between 2 different MR angiography sessions performed before surgery. The clinical variables of the stable and unstable disease groups were compared, and the association between unstable disease and postoperative diffusion-weighted imaging (DWI)–detected lesion was assessed through univariate and multivariate analyses with generalized estimating equations.

RESULTS

Of 134 direct bypass procedures performed after patients had undergone at least 2 sessions of MR angiography, 24 (17.9%) were classified as cases of unstable disease. Age younger than 3 years (p = 0.029), underlying disease causing moyamoya syndrome (p = 0.049), and radiographic evidence of infarction (p = 0.030) were identified as factors associated with unstable disease. Postoperative DWI-defined lesions were detected after 13 of 140 procedures (9.3%), although only 4 lesions (2.9%) could be classified as a permanent complication. The incidence of postoperative DWI-detected lesions in the unstable group was notable at 33.3% (8 of 24). Univariate analysis revealed that unstable disease (p < 0.001), underlying disease (p = 0.028), and recent stroke (p = 0.012) were factors associated with DWI-detected lesions. Unstable disease remained statistically significant after adjustment for covariates in both the primary and sensitivity analyses (primary analysis: OR 6.62 [95% CI 1.79–24.5]; sensitivity analysis: OR 5.36 [95% CI 1.47–19.6]).

CONCLUSIONS

Unstable moyamoya disease, more prevalent in younger patients and those with underlying disease, is a possible risk factor for perioperative ischemic complications. Recognition of unstable moyamoya disease may contribute to an improved surgical result through focused perioperative management based on appropriate surgical risk stratification.