Clinical Features and Long-Term Outcomes of Unilateral Moyamoya Disease

Clinical and genetic factors associated with contralateral progression in unilateral moyamoya disease: Longitudinal and Cross-Sectional Study

Objective

This study aimed to explore the long-term outcome of unilateral moyamoya disease and predict the clinical and genetic factors associated with contralateral progression in unilateral moyamoya disease.

Methods

We retrospectively recruited unilateral moyamoya disease patients with available genetic data who underwent encephaloduroarteriosynangiosis (EDAS) surgery at our institution from January 2009 to November 2017. Long-term follow-up data, including clinical outcomes, angiographic features, and genetic information, were analyzed.

Results

A total of 83 unilateral moyamoya disease patients with available genetic data were enrolled in our study. The mean duration of clinical follow-up was 7.9 ± 2.0 years. Among all patients, 19 patients demonstrated contralateral progression to bilateral disease. Heterozygous Ring Finger Protein 213 p.R4810K mutations occurred significantly more frequently in unilateral moyamoya disease patients with contralateral progression. Furthermore, patients with contralateral progression typically demonstrated an earlier age of onset than those with non-progressing unilateral moyamoya disease. In the contralateral progression group, posterior circulation involvement was observed in 11 (11/19, 57.9%) patients compared to 12 (12/64, 18.8%) in the non-contralateral progression group (P = 0.001). The time to peak of cerebral perfusion and neurological status showed significant postoperative improvement.

Conclusion

Long-term follow-up revealed that the EDAS procedure might provide benefits for unilateral moyamoya disease patients. Ring Finger Protein 213 p.R4810K mutations, younger age, and posterior circulation involvement might predict the contralateral progression of unilateral moyamoya disease.

[Moyamoya disease in adults: treatment methods in modern era]

Moyamoya angiopathy is a chronic progressive cerebrovascular disease characterized by stenosis and occlusion of the distal segments of the internal carotid arteries and/or proximal segments of the middle and anterior cerebral arteries, with a gradual compensatory restructuring of the cerebral circulation to the system of the external carotid arteries. Today, the main treatment method for Moyamoya angiopathy is surgical revascularization of the brain. A search and analysis of publications on the treatment of adult patients with Moyamoya angiopathy was carried out in the PubMed and Medscape databases over the past 10 years. We present a case of an adult female patient with a hemorrhagic form of Moyamoya angiopathy stage IV according to J. Suzuki, who underwent staged combined revascularization of both cerebral hemispheres. Surgical revascularization included the creation of a low-flow extra-intracranial shunt combined with a combination of indirect synangiosis. The combination of direct and indirect methods of surgical revascularization enables to achieve the development of an extensive network of collaterals and fully compensate for cerebral circulatory disorders both in the early and late postoperative periods, which is confirmed by instrumental diagnostic data. Combined revascularization is the most effective modern method of treating patients with Moyamoya angiopathy due to the complementary influence of direct and indirect components of revascularization.

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.

Factors Influencing Collateral Circulation Formation After Indirect Revascularization for Moyamoya Disease: a Narrative Review

Indirect revascularization is one of the main techniques for the treatment of Moyamoya disease. The formation of good collateral circulation is a key measure to improve cerebral blood perfusion and reduce the risk of secondary stroke, and is the main method for evaluating the effect of indirect revascularization. Therefore, how to predict and promote the formation of collateral circulation before and after surgery is important for improving the success rate of indirect revascularization in Moyamoya disease. Previous studies have shown that vascular endothelial growth factor, endothelial progenitor cells, Caveolin-1, and other factors observed in patients with Moyamoya disease may play a key role in the generation of collateral vessels after indirect revascularization through endothelial hyperplasia and smooth muscle migration. In addition, mutations in the genetic factor RNF213 have also been associated with this process. This study summarizes the factors and mechanisms influencing collateral circulation formation after indirect revascularization in Moyamoya disease.

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.

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.

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

Background

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

Methods

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

Results

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

Conclusion

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

Trial registration.

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

Supplementary Information

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

Image-based patient-specific flow simulations are consistent with stroke in pediatric cerebrovascular disease

Moyamoya disease (MMD) is characterized by narrowing of the distal internal carotid artery and the circle of Willis (CoW) and leads to recurring ischemic and hemorrhagic stroke. A retrospective review of data from 50 pediatric MMD patients revealed that among the 24 who had a unilateral stroke and were surgically treated, 11 (45.8%) had a subsequent, contralateral stroke. There is no reliable way to predict these events. After a pilot study in Acta-/- mice that have features of MMD, we hypothesized that local hemodynamics are predictive of contralateral strokes and sought to develop a patient-specific analysis framework to noninvasively assess this stroke risk. A pediatric MMD patient with an occlusion in the right middle cerebral artery and a right-sided stroke, who was surgically treated and then had a contralateral stroke, was selected for analysis. By using an unsteady Navier-Stokes solver within an isogeometric analysis framework, blood flow was simulated in the CoW model reconstructed from the patient's postoperative imaging data, and the results were compared with those from an age- and sex-matched control subject. A wall shear rate (WSR) > 60,000 s-1 (about 12 × higher than the coagulation threshold of 5000 s-1 and 9 × higher than control) was measured in the terminal left supraclinoid artery; its location coincided with that of the subsequent postsurgical left-sided stroke. A parametric study of disease progression revealed a strong correlation between the degree of vascular morphology altered by MMD and local hemodynamic environment. The results suggest that an occlusion in the CoW could lead to excessive contralateral WSRs, resulting in thromboembolic ischemic events, and that WSR could be a predictor of future stroke.

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.

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 and Long-Term Outcome of Headaches Associated With Moyamoya Disease in the Chinese Population-A Cohort Study

Background: Headache associated with Moyamoya disease (HAMD) in the Chinese population is not well-described. The long-term outcome of surgical revascularization and natural course of HAMD has not been disclosed either. Methods: A headache screening questionnaire in China based on the ICHD2 and a face-to-face interview performed by an experienced neurologist were used to investigate headache characteristics and frequency and pain intensity in the 3 months before admission, and a telephone interview was used for the follow-up of a large cohort of 119 Chinese patients with HAMD. Results: Headache intensity was rated as scores of 5.9 ± 2.0 on a visual analog scale (VAS), ranging from 0 to 10, in the 3 months before admission. Forty-six patients (38.6%) were categorized as having migraine-like headaches, 29 patients (24.3%) were categorized as having tension type-like headaches, and 44 patients (36.9%) had a combination of both. The majority of patients had migraine-like headaches (n = 34, 73.9%) with a migrainous aura. Both the frequency and intensity of the headache improved significantly in patients treated with surgical revascularization (n = 96, 80.7%) or the conservative treatment (n = 23, 19.3%) in a long-term follow-up. Conclusion: HAMD frequently presented with a migraine-like headache (75.5% in total). A tension type headache was present in 60.9% of patients. The symptom of dizziness is common in patients with HAMD (60.5%), and 19 of them (26.4%) met the diagnose of vestibular migraine. Both intensity and frequency of HAMD show a trend of spontaneous remission in a long-term follow-up, and there is no difference in long-term outcomes of HAMD between surgical revascularization and conservative treatment, which indicates that the effect of bypass intervention on HAMD may be a placebo effect.

Clinical Course of Unilateral Moyamoya Disease

BACKGROUND

The natural history of unilateral moyamoya disease (MMD) progressing to bilateral MMD remains an enigma in modern vascular neurosurgery. Few, small series with limited follow-up have reported relatively high rates of contralateral stenosis progression.

OBJECTIVE

To review our large series of unilateral MMD patients and evaluate radiographic and surgical progression rates, and identify any factors associated with progression.

METHODS

We included all unilateral MMD cases treated from 1991 to 2017 in an observational study. We examined time to contralateral radiographic progression and contralateral progression requiring surgery. Using Cox regression analysis, we evaluated factors potentially associated with contralateral progression.

RESULTS

There were 217 patients treated for unilateral MMD. About 71% were female, and the average age at first surgery was 33.8 yr. Average follow-up was 5.8 yr (range 1-22 yr). A total of 18 patients (8.3%) developed contralateral progression. And 8 of these (3.7%) developed progression requiring bypass surgery. Baseline stenosis and hyperlipidemia (HLD) were significantly associated with radiographic progression (hazard ratio [HR] = 9.7, P = .006; HR = 4.0, P = .024). Baseline stenosis was associated with surgical progression (HR = 44.2, P = .002). Results were similar when controlling for possible confounders using multivariate regression.

CONCLUSION

Previous series showed relatively high rates of progression in unilateral MMD (15%-30%), but these studies were small and long-term follow-up was rarely available. Our large series indicates that the rate of progression is lower than previously reported but still warrants yearly noninvasive screening. These data may provide indirect support for statin therapy in MMD.

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.

Angiographic characteristics in Moyamoya disease with the p.R4810K variant: a propensity score-matched analysis

BACKGROUND AND PURPOSE

The p.R4810K variant was identified as a strong susceptibility in patients with Moyamoya disease (MMD). The aim of this study was to investigate the angiographic characteristics in MMD with the p.R4810K variant.

METHODS

Angiographic characteristics were compared between patients with wild-type p.R4810K variant (GG) and patients with heterozygous p.R4810K variant (GA) after 1:1 propensity score matching, including Suzuki stage, collateral circulation and external carotid artery (ECA) collateral. Collateral circulation was graded with scores ranging from 0 to 12: posterior collateral circulation from the posterior cerebral artery to the middle cerebral artery and anterior cerebral artery was scored from 0 to 6; anterior collateral circulation was scored as 6 to 0 corresponding to Suzuki stages 0 to 6.

RESULTS

A total of 489 patients were screened; 133 pairs were obtained after 1:1 propensity score matching. Compared with the patients in the GA group, unilateral MMD was more frequent in the GG group (P = 0.026). Hemispheres in the GA group (86/266) had more posterior cerebral artery involvement than hemispheres in the GG group (48/266) (P < 0.001). Hemispheres in the GA group had a lower grade in collateral circulation than hemispheres in the GG group (P = 0.011), but ECA collateral was more frequently observed in the GA group than in the GG group (53.4% vs. 39.8%, P = 0.002). Superficial temporal artery and occipital artery collateral was more frequently observed in the GA group than in the GG group (P < 0.05).

CONCLUSIONS

Patients in the GA group had lower grades in collateral circulation than patients in the GG group, but ECA collateral was more frequently observed in the GA group than in the GG group.

Digital subtraction angiographic characteristics of progression of moyamoya disease 6 months prior to surgical revascularisation

Background

Evidence on the natural angiographic course of moyamoya disease (MMD) is lacking. It takes about 6 months for waiting for revascularisation surgery. The issue of when to perform subtraction angiography (DSA) for follow-up remains unclear. We investigated the natural course of MMD by DSA and attempted to determine the best interval to perform the follow-up DSA.

Methods

This is a single-centre cohort study of Chinese MMD inpatients treated from 1 January 2015 to 31 August 2019. Their angiographic findings were evaluated on Suzuki stage and collateral circulation between two follow-ups of the same hemisphere.

Results

A total of 110 patients who met the criteria were enrolled in this study. After a median 6 months follow-up, five patients (4.5%) had progression, four females and one male. Time interval of progression ranged from 4 to 137 months with a mean of 61.4 months. Of five patients with progression, four had unilateral lesion (two ipsilateral and two contralateral) and one had bilateral lesions. Collateral circulation was changed in three of five patients.

Conclusions

The angiographic evidence of progression in MMD was rare in the short-term follow-up, and most patients with progression had initial unilateral involvement. DSA re-examination may be not needed in patients with bilateral MMD, but needed in unilateral MMD.

Association Between p.R4810K Variant and Long-Term Clinical Outcome in Patients With Moyamoya Disease

Objective: To estimate the association between p. R4810K variant and clinical outcomes of patients with moyamoya disease (MMD).

Methods: The p.R4810K genetic variant was genotyped among 498 Chinese patients with MMD conducted from June 1, 2012, to June 31, 2017. Data was obtained by retrospective chart review, follow-up information and outcome were obtained through clinical visits and telephone.

Results: Among 498 patients, 361 (72.5%) were wild-type patients (G/G), 133 (26.7%) heterozygous patients (G/A), and 4 (0.8%) homozygotes (A/A). Compared with GG group, the patients in the G/A+A/A group were younger at diagnosis and had more familial cases, more transient ischemic attack cases, more posterior cerebral artery involved hemispheres, less unilateral lesions. After the median 53 months follow-up, strokes occurred in 9 patients in the G/A+A/A group and in 52 in the G/G group. Multivariate Cox regression analysis showed that the history of hypertension (HR, 2.294; 95% CI, 1.251–4.206; p = 0.007), the presence of TIA (HR, 0.319; 95% CI, 0.120–0.846; p = 0.022), and the Suzuki stage (HR, 1.510; 95% CI, 1.129–2.018; p = 0.005) were associated with recurrent stroke. The p.R4810K (HR, 0.601; 95% CI, 0.292–1.239; p = 0.168) was not associated with recurrent stroke. Multivariate logistic regression analysis showed that recurrent stroke (OR, 5.997; 95% CI, 2.583–13.924; p = 0.000) was the only factor associated with unfavorable neurological status. And the p.R4810K (OR, 0.885; 95% CI, 0.482–1.627; p = 0.695) was not associated with neurological status.

Conclusions: Compared to the patients in G/G group, patients in G/A+A/A group exhibited different clinical features, and had a lower rate of recurrent stroke and better clinical outcome after early medical and surgical interventions. Multivariate COX and logistic regression analysis showed that p.R4810Kvariant was not related to either recurrent stroke or neurological status. The p.R4810Kvariant may not be associated with long-term clinical outcome in Chinese patients with MMD.

Patterns of Acute Intracranial Hemorrhage in Adult Patients with Bilateral and Unilateral Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is a rare cerebrovascular disease. The difference of hemorrhagic patterns in adult patients with bilateral and unilateral MMD is still unclear.

OBJECTIVE

For a better understanding of their characteristics, we compared the patterns of acute intracranial hemorrhage in adult patients with bilateral and unilateral MMD.

METHODS

Adult MMD patients with acute intracranial hemorrhage were retrospectively included. Clinical and radiological characteristics of adult patients with bilateral and unilateral MMD were collected and analyzed. Chi-square test, t-test, or rank sum test were used for statistical analyses.

RESULTS

A total of 107 patients were included. Among 74 patients with bilateral MMD, 9 (12.2%) were at Suzuki Stage 2, 48 (64.9%) were at Stage 3, 16 (21.6%) were at Stage 4, and another (1.4%) was at Stage 5. However, in patients with unilateral MMD, 8 (24.2%) were at Stage 2, 23 (69.7%) were at Stage 3, and 2 (6.1%) were at Stage 4. Intraparenchymal hemorrhage was found in 40 (54.1%) patients with bilateral MMD and 16 (48.5%) patients with unilateral MMD (P=0.594). Intraventricular hemorrhage was shown in 65 (87.8%) patients with bilateral MMD and 19 (57.6%) patients with unilateral MMD (P<0.001). Subarachnoid hemorrhage was observed in 17 (23.0%) patients with bilateral MMD and 18 (54.5%) patients with unilateral MMD (P=0.001).

CONCLUSION

Unilateral MMD patients with acute intracranial hemorrhage are at the earlier Suzuki stage than the bilateral MMD patients. Intraventricular hemorrhage occurs more frequently in bilateral MMD, while subarachnoid hemorrhage is more frequent in unilateral MMD.

Long-term Outcomes After Encephaloduroarteriosynangiosis in Adult Patients with Moyamoya Disease Presenting with Ischemia

BACKGROUND

In adult Moyamoya disease (MMD), there remains controversy about the effectiveness of revascularization surgeries because randomized studies have not been performed to compare the efficacy of surgical techniques. This study was conducted to assess the most appropriate surgical treatment for adult patients with MMD.

METHODS

Encephaloduroarteriosynangiosis (EDAS) was performed on 247 hemispheres in 145 patients. The clinical and demographic characteristics of patients were obtained via retrospective chart review. Clinical and angiographic states were evaluated retrospectively using quantitative methods. The mean duration of clinical follow up was 141.4 ± 19.5 months.

RESULTS

A total of 247 EDAS procedures were performed in 145 patients, including 15 EDAS performed using the occipital artery as the donor vessel. The mortality rate was 0%, and the permanent morbidity rates were 1.2% per operation and 2.0% per person. The mean modified Rankin Scale score was 1.21 ± 1.31 postoperatively and 1.01 ± 1.39 at the last follow-up. Of the 109 hemispheres studied, 45% were classified as grade A, 34% as grade B, and 21% as grade C collateral circulation. The annual rates of stroke were calculated to be 0.73% per person-year. Overall, the 1-,5-, and 10-year actuarial stroke rates were 2.1±1.2%, 6.8±2.1%, and 8.9±2.4%, respectively. Bilateral involvement was a common significant factor in any, hemorrhagic, and ischemic strokes. Hypertension was a risk factor for ischemic strokes during follow-up.

CONCLUSIONS

EDAS is an effective procedure in a Chinese cohort of patients with MMD. EDAS resulted in satisfactory long-term improvement of clinical states and prevention of recurrent strokes.

Clinical Features, Surgical Treatment, and Long-Term Outcome in Children with Hemorrhagic Moyamoya Disease

BACKGROUND

The objective of this study was to elucidate the clinical features, surgical treatment, and long-term outcome in pediatric patients with moyamoya disease (MMD).

METHODS

We retrospectively reviewed 46 pediatric patients with hemorrhagic MMD at Beijing Tiantan Hospital. Clinical features, radiological findings, and outcomes were analyzed.

RESULTS

The mean age at diagnosis was 13.6 ± 3.6 years. The ratio of girls to boys was 1.0:1.1. Familial occurrence was 4.3%. The primary symptoms at initial presentation were intraventricular hemorrhage (IVH) (47.8%), intracerebral hemorrhage (ICH) (37.0%), ICH with IVH (13.0%), and subarachnoid hemorrhage (2.2%). Most patients presented with Suzuki stage 3 or 4 MMD. Posterior cerebral artery involvement was observed in 22 (18.4%) patients. During the average follow-up of 126.1 ± 96.0 months, 11 of 53 (20.8%) conservatively treated hemispheres and 1 of 36 (2.8%) surgically treated hemispheres experienced a stroke event (P < .05). There was a difference in the Kaplan-Meier curve of stroke between the 2 groups (log rank test, P < .05). What is more, the rate of perfusion improvement in surgically treated patients was higher than in those conservatively treated patients 3 months after discharge (P < .05).

CONCLUSIONS

Revascularization surgery has a role in the prevention of recurrent strokes and can improve cerebral perfusion in pediatric patients with hemorrhagic MMD. Further study is needed to determine which bypass surgery is more beneficial for pediatric patients with hemorrhagic MMD.

Baseline Hemodynamic Impairment and Future Stroke Risk in Adult Idiopathic Moyamoya Phenomenon: Results of a Prospective Natural History Study

BACKGROUND AND PURPOSE

The purpose was to test the hypothesis that increased oxygen extraction fraction (OEF), a marker of severe hemodynamic impairment measured by positron emission tomography, is an independent risk factor for subsequent ischemic stroke in this population.

METHODS

Adults with idiopathic moyamoya phenomena were recruited between 2005 and 2012 for a prospective, multicenter, blindly adjudicated, longitudinal cohort study. Measurements of OEF were obtained on enrollment. Subjects were followed up for the occurrence of ipsilateral ischemic stroke at 6-month intervals. Patients were censored at the time of surgical revascularization or at last follow-up. The primary analysis was time to ischemic stroke in the territory of the occlusive vasculopathy.

RESULTS

Forty-nine subjects were followed up during a median of 3.7 years. One of 16 patients with increased OEF on enrollment had an ischemic stroke and another had an intraparenchymal hemorrhage. Three of 33 patients with normal OEF had an ischemic stroke. On a per-hemisphere basis, 21 of 79 hemispheres with moyamoya vasculopathy had increased OEF at baseline. No ischemic strokes and one hemorrhage occurred in a hemisphere with increased OEF (n=21). Sixteen patients (20 hemispheres), including 5 with increased OEF at enrollment, were censored at a mean of 5.3 months after enrollment for revascularization surgery.

CONCLUSIONS

The risk of new or recurrent stroke was lower than expected. The low event rate, low prevalence of increased OEF, and potential selection bias introduced by revascularization surgery limit strong conclusions about the association of increased OEF and future stroke risk.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00629915.

Long-Term Outcome After Conservative Treatment and Direct Bypass Surgery of Moyamoya Disease at Late Suzuki Stage

OBJECTIVE

To investigate the long-term outcomes after conservative and direct surgical treatment for patients with moyamoya disease (MMD) at late Suzuki stage.

METHODS

We retrospectively reviewed 82 patients (164 hemispheres) with MMD at late Suzuki stage at Beijing Tiantan Hospital. Clinical features, radiologic findings, and outcomes were analyzed.

RESULTS

The mean age at diagnosis was 36.4 ± 11.7 years. The distribution of the initial Suzuki stage of MMD was as follows: stage 4, n = 113; stage 5, n = 45; stage 6, n = 6, posterior cerebral artery involvement was observed in 41 hemispheres (25.0%). The incidence of postoperative stroke (<48 hours) was 6.7%. During the average follow-up of 55.1 ± 16.2 months, including postoperative and follow-up strokes, 7 of 75 conservatively treated hemispheres (9.3%) and 9 of 89 surgically treated patients (10.1%) experienced a stroke event; there was no statistical significance in the Kaplan-Meier curve of stroke incidence between the surgical group and conservative group (log-rank test, P = 0.848). However, the rate of perfusion improvement in direct bypass surgically treated patients was higher than in those conservatively treated patients 3 months after discharge (P < 0.05).

CONCLUSIONS

Although direct bypass surgery was shown to effectively improve the cerebral perfusion in patients with MMD at late Suzuki stage, compared with conservative treatment, it did not reduce the risk of recurrent stroke. Further study is needed to determine whether direct bypass surgery is effective in patients with MMD at late Suzuki stage.