Clinical features, surgical treatment and long-term outcome in adult patients with Moyamoya disease in China

Stroke Events and Risk Factors in Older Patients with Moyamoya Disease

BACKGROUND

We aimed to comprehensively analyze the epidemiology, natural history, stroke events and their risk factors, and the RNF213 p.Arg4810Lys variant in older patients with moyamoya disease (MMD).

METHODS

We enrolled patients with MMD followed-up at our hospital between 2000 and 2023. Those who developed MMD at age ≥60 years or were diagnosed at a younger age and followed-up after age 60 years were included. Baseline characteristics, onset type, radiologic features, and RNF213 p.Arg4810Lys variant status were investigated.

RESULTS

Among 56 patients with 100 affected hemispheres, 62 were asymptomatic, 26 experienced ischemic onset, and 12 had hemorrhagic onset. A higher incidence of anterior choroidal artery (AchA) dilatation and lower proportion of favorable modified Rankin scale scores were detected in hemorrhagic onset, whereas greater prevalence of bypass surgery in ischemic onset. Of 76 asymptomatic hemispheres at the age of 60 years, subsequent stroke events occurred in 10 hemispheres, comprising 8 hemorrhages and 2 ischemias. Risk factors for de novo hemorrhage in asymptomatic hemispheres included AchA dilatation and choroidal anastomosis. Comparison of the RNF213 p.Arg4810Lys variant status showed no significant differences in baseline characteristics, onset types, or imaging findings, except for a higher percentage of patients in the GA group with a family history of MMD.

CONCLUSIONS

Hemorrhagic events were the most prevalent and prognostically deteriorating factors in older patients with MMD aged ≥60 years. AchA dilatation and choroidal anastomosis were predictors of de novo hemorrhage in asymptomatic nonsurgical hemispheres in older patients with MMD.

Nonalcoholic fatty liver disease is an independent risk factor for ischemic stroke after revascularization in patients with Moyamoya disease: a prospective cohort study

BACKGROUND

The study aimed to investigate the association between nonalcoholic fatty liver disease (NAFLD) and ischemic stroke events after revascularization in patients with Moyamoya disease (MMD).

METHODS

This study prospectively enrolled 275 MMD patients from September 2020 to December 2021. Patients with alcoholism and other liver diseases were excluded. NAFLD was confirmed by CT imaging or abdominal ultrasonography. Stroke events and modified Rankin Scale (mRS) scores at the latest follow-up were compared between the two groups.

RESULTS

A total of 275 patients were enrolled in the study, among which 65 were diagnosed with NAFLD. Univariate logistic regression analysis showed that NAFLD (P = 0.029) was related to stroke events. Multivariate logistic regression analysis showed that NAFLD is a predictor of postoperative stroke in MMD patients (OR = 27.145, 95% CI = 2.031-362.81, P = 0.013). Kaplan-Meier analysis showed that compared with MMD patients with NAFLD, patients in the control group had a longer stroke-free time (P = 0.004). Univariate Cox analysis showed that NAFLD (P = 0.016) was associated with ischemic stroke during follow-up in patients with MMD. Multivariate Cox analysis showed that NAFLD was an independent risk factor for stroke in patients with MMD (HR = 10.815, 95% CI = 1.259-92.881, P = 0.030). Furthermore, fewer patients in the NAFLD group had good neurologic status (mRS score ≤ 2) than the control group (P = 0.005).

CONCLUSION

NAFLD was an independent risk factor for stroke in patients with MMD after revascularization and worse neurological function outcomes.

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.

Future of Endovascular and Surgical Treatments of Atherosclerotic Intracranial Stenosis

Intracranial atherosclerotic disease and resultant intracranial stenosis is a global leading cause of stroke, and poses an ongoing treatment challenge. Among patients with intracranial stenosis, those with hemodynamic compromise are at high risk for recurrent stroke despite medical therapy and risk factor modification. Revascularization of the hypoperfused territory is the most plausible treatment strategy for these high-risk patients, yet surgical and endovascular therapies have not yet shown to be sufficiently safe and effective in randomized controlled trials. Advances in diagnostic and therapeutic technologies have led to a resurgence of interest in surgical and endovascular treatment strategies, with a growing body of evidence to support their further evaluation in the treatment of select patient populations. This review outlines the current and emerging endovascular and surgical treatments and highlights promising future management strategies.

[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.

ABO blood types may affect transient neurological events after surgical revascularization in patients with moyamoya disease: a retrospective single center study

BACKGROUND

Moyamoya disease (MMD) is a cerebrovascular disease with unknown cause. Patients with MMD disease usually experience transient neurological events (TNEs) after revascularization surgery. This retrospective single-center study was aimed to explore the risk factors of postoperative TNEs after surgical revascularization in patients with MMD.

METHODS

We selected 324 patients who underwent surgical revascularization between January 2017 and September 2022 in our center. The perioperative characteristics of the patients were recorded and the outcome was TNEs after surgery. An analysis of risk factors contributing to postoperative TNEs by using logistic regression model.

RESULTS

Three hundred twelve patients were enrolled, and the incidence of postoperative TNEs was 34% in our study. Males were more likely to suffer from postoperative TNEs (OR = 2.344, p = 0.002). Preoperative ischemic presentation (OR = 1.849, p = 0.048) and intraoperative hypotension (OR = 2.332, p = 0.002) were associated with postoperative TNEs. Compared to patients with blood type O, patients with blood type A (OR = 2.325, p = 0.028), B (OR = 2.239, p = 0.027) and AB (OR = 2.938, p = 0.019) had a significantly higher incidence of postoperative TNEs. A risk prediction model for postoperative TNEs was established, and the established risk prediction area under the receiver operating characteristic curve (ROC) of the model was 0.741.

CONCLUSIONS

Males, preoperative ischemic presentation and intraoperative hypotension were associated with postoperative TNEs. We also found a possible link between postoperative TNEs and ABO blood types after surgical revascularization for moyamoya patients.

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.

Surgical outcomes following encephaloduroarteriosynangiosis in moyamoya disease associated with hyperhomocysteinemia

INTRODUCTION

This study investigated the effect of indirect revascularization surgery in adult patients with moyamoya disease (MMD) complicated with hyperhomocysteinemia (HHcy), and the effect of HHcy on the progression of adult MMD.

METHODS

A retrospective case-control study was conducted in patients with MMD, with or without HHcy (n = 123). Postoperative collateral angiogenesis was evaluated using the Matsushima grading system and disease progression using the Suzuki staging system. Cerebral blood flow was evaluated before and after surgery using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) and neurological function prognosis using the improved Rankin score (mRS). Univariate and multivariate logistic regression analyses were performed to determine risk factors for the clinical outcomes.

RESULTS

There was no significant difference in the Suzuki stage composition ratios between the HHcy group and the non-HHcy group before and after surgery. Non-HHcy patients were more likely to grow new collateral circulating vessels after encephaloduroarteriosynangiosis (EDAS). Moreover, postoperative DSC-MRI indicated that the time to peak significantly improved.

CONCLUSIONS

HHcy level may be a specific predictor of adverse clinical outcomes after EDAS in patients with MMD and a risk factor for poor collateral circulation and poor prognosis. Patients with MMD complicated with HHcy need to strictly control homocysteine levels before EDAS surgery.

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

Rationale

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

Objective

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

Methods and results

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

Conclusions

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

Incidental Moyamoya Disease in an Elderly Patient Presenting With Acute Ischemic Pontine Stroke

Moyamoya disease (MMD) is a rare occlusive cerebrovascular disease that is characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches with compensatory development of dilated and fragile collateral vasculature at the base of the brain. MMD has a bimodal age distribution commonly affecting children and adults, whereas onset in the elderly population is a rare occurrence. Here, we present a case of a 78-year-old patient of Indonesian descent who was incidentally found to have moyamoya arteriopathy after presenting with acute ischemic stroke in the left pons. The patient underwent diagnostic cerebral angiogram that showed right middle cerebral artery stenosis with pathognomonic collateral moyamoya vessels. The patient was discharged on antiplatelet therapy. We report a rare case of an elderly patient with MMD. The role of medical or surgical management in asymptomatic MMD in elderly patients remains largely unknown.

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

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

Superficial temporal artery-middle cerebral artery bypass in combination with encephalo-myo-synangiosis in Chinese adult patients with moyamoya disease

Objective

To evaluate the feasibility and safety of superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis in combination with encephalo-myo-synangiosis (EMS) in Chinese adult patients with moyamoya disease (MMD).

Methods

A total of 65 patients with MMD who underwent combined STA-MCA bypass + EMS surgical revascularisation were included in this study. Each patient had a follow-up visit 6 months after discharge. Early bypass function was evaluated via computed tomography angiography and digital subtraction angiography, which were performed preoperatively and at 6 months after surgery. The perfusion parameters of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to peak (TTP) were obtained and analysed. The clinical status of each patient was evaluated using a modified Rankin scale (mRS) preoperatively and at 1 week and 6 months after surgery.

Results

Among the 65 enrolled patients, postoperative complications were observed in 5 (7.69%) patients, with 2 cases of dysphasia, 2 cases of new cerebral infarction and 1 case of seizure. Six months after surgery, 66 out of 68 hemispheres were found to have a functioning extra-intracranial bypass, and the patency rate was 97.06%. In terms of CBF perfusion, both the CBF and CBV increased significantly, while the MTT and TTP decreased after surgery. The mRS scores measured 1 week and 6 months after surgery were much lower than those measured preoperatively.

Conclusion

A direct STA-MCA bypass procedure in combination with indirect EMS bypass is feasible and safe for Chinese adult patients with MMD.

Short- and long-term outcomes of moyamoya patients post-revascularization

OBJECTIVE

The post-bypass stroke risk factors and long-term outcomes of moyamoya patients are not well documented. Therefore, the authors studied 30-day stroke risks and patients’ long-term physical, functional, and social well-being.

METHODS

This was a single-institution combined moyamoya disease (MMD) database interrogation and questionnaire study. From 1991 to 2014, 1250 revascularization procedures (1118 direct bypasses, 132 indirect bypasses) were performed in 769 patients. Completed questionnaires were received from and available for analysis on 391 patients, and 6-month follow-up data were available for 96.4% (741/769) of the patients.

RESULTS

The patients consisted of 548 females and 221 males, with a mean age of 32 years (range 1–69 years). Three hundred fifty-eight bypasses were performed in 205 pediatric patients (73% direct bypasses), and 892 revascularizations were performed in 564 adults (96% direct bypasses). Fifty-two patients (6.8%) developed major strokes with a worsening modified Rankin Scale (mRS) score within 30 days postoperatively. The 30-day major stroke risk was 5.3% (41/769) and 2.6% (12/467) after the first and second bypasses, respectively. Logistic regression analysis revealed that older age, modified MRI (mMRI) score, and hemodynamic reserve (HDR) score are clearly associated with higher postoperative stroke risks. Over a mean follow-up of 7.3 years (range 0.5–26 years), the long-term stroke risk among 741 patients was 0.6% per patient-year; 75% of these patients had excellent outcomes (mRS score 0–1). The long-term outcome questionnaire study showed that 84% (234/277) of patients reported resolution or improvement in their preoperative headache, 83% (325/391) remained employed or in school, and 87% (303/348) were self-caring.

CONCLUSIONS

In this large, single-center surgical series, most of the adult and pediatric patients had direct revascularization, with a 4.2% per-bypass-procedure (6.8% per patient) 30-day major stroke risk and a 0.6% per-patient-year long-term stroke risk. The authors identified various risk factors that are highly correlated with postoperative morbidity (age, mMRI score, and HDR score) and are involved in ongoing work to develop the predictive modeling for future patient selection and treatment.

Recognition of the Effect of Indirect Revascularization for Moyamoya Disease: The Balance Between the Stage Progression and Neoangiogenesis

Objective

To explore the long-term progression of neoangiogenesis after indirect revascularization for moyamoya disease (MMD).

Methods

We enrolled patients who were diagnosed with MMD and treated by encephaloduroarteriosynangiosis (EDAS) surgery at our center from December 2002 through September 2009. A comparative study between short-term (6–12 months) and long-term (duration ≥ 8 years) follow-up angiographies was performed. The development of collateral circulation through EDAS was graded according to the system described by the Matsushima grade system.

Results

A total of 78 patients who received indirect EDAS were enrolled in the study. The mean age at the first operation was 26.9 ± 15.0 years. The Matsushima grades of the same hemisphere were higher at the long-term follow-up compared with the short-term follow-up. Importantly, no attenuation was observed in any hemisphere during the long-term follow-up. In total, 51 hemispheres (32.7%) and 26 hemispheres (16.6%) had progression during the short-term and the long-term follow-up, respectively. The ipsilateral Suzuki stage showed a significant negative correlation with progression pace. Furthermore, higher Suzuki stages were significantly correlated with the postsurgical Matsushima grade at both time points. A total of nine strokes (11.5%) occurred in 78 patients was reported at the long-term follow-up. The annual incidence rate of recurrent strokes was higher for the stage progression group than for the stable group.

Conclusion

For patients with MMD, postsurgical neoangiogenesis after indirect bypass continuously improved with time. The short-term progression of the internal carotid artery (ICA) might be attributed to cerebral revascularization, while the long-term progression should be attributed to the natural progression of the disease.

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

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

Clinical and Genetic Risk Factors of Long-Term Outcomes after Encephaloduroarteriosynangiosis in Moyamoya Disease in China

OBJECTIVES

This retrospective study was conducted to analyze the associations between ring finger protein 213 p.R4810K variant, clinical features and long-term outcomes in patients with moyamoya disease (MMD) after encephaloduroarteriosynangiosis treatment.

MATERIALS AND METHODS

A total of 2,545 patients with MMD in China were included in this study (median of follow-up duration: 32.00 months). Multiple Cox regression models were used to assess the associations between p.R4810K variant, clinical features and long-term outcomes.

RESULTS

For all patients, in multivariate Cox analysis, no association was observed between p.R4810K and long-term outcomes. Pediatric onset (HR, 0.38; 95%CI, 0.25-0.59) and headache (HR, 0.26; 95%CI, 0.08-0.83) were inversely and hypertension (HR, 1.43 95%CI, 1.06-1.94), diabetes (HR, 1.55; 95%CI, 1.00-2.40), bilateral lesions (HR, 2.73; 95%CI, 1.12-6.65) and posterior cerebral artery involvement (HR, 1.44; 95%CI, 1.08-1.90) were positively associated with follow-up stroke (all P < 0.05). Pediatric onset (HR, 0.46; 95%CI, 0.26-0.82) was inversely and hyperlipidemia (HR, 1.83; 95%CI, 1.23-2.73), smoking (HR, 1.86; 95%CI, 1.13-3.07), high Suzuki angiographic stage (HR, 1.71, 95%CI, 1.09-2.70), poor admission neurologic status (HR, 8.93; 95%CI, 6.49-12.29) and follow-up stroke (HR, 8.31; 95%CI, 6.01-11.49) were positively associated with poor neurologic outcome at the last follow-up visit (all P < 0.05). The factors were not consistent in the different groups of age at onset.

CONCLUSIONS

In our study, p.R4810K may play no role in long-term outcomes in Chinese MMD. Clinical features including age at onset, initial symptoms, risk factors of stroke, imaging, poor admission neurologic status were associated with poor outcomes in MMD after EDAS.

Mapping Trends in Moyamoya Angiopathy Research: A 10-Year Bibliometric and Visualization-Based Analyses of the Web of Science Core Collection (WoSCC)

Background: Moyamoya angiopathy (MMA), which includes moyamoya disease (MMD) and moyamoya syndrome (MMS), is an uncommon cerebrovascular condition characterized by recurrent stroke. We carried out a bibliometric analysis to examine the development of and research trends in MMA research.

Methods: Studies published between 2010 and 2019 on MMA were retrieved from the Web of Science Core Collection (WoSCC) on August 14, 2020, and bibliometric and visualization-based analyses were performed by using three different scientometric tools: HistCite, VOSviewer, and CiteSpace.

Results: A total of 1,896 publications published in 384 journals by 6,744 authors, 1,641 institutions and 56 countries/regions were included in the analyses. Annual publication outputs increased from 2010 to 2019. The USA, Japan and China were three key contributors to this study field. Capital Medical University, Seoul National University, and Stanford University were three major institutions with larger numbers of publications. Zhang D, World Neurosurgery, Kuroda S, and STROKE were the most prolific author, prolific journal, top co-cited author and top co-cited journal, respectively. The top five keywords during this period were moyamoya disease, revascularization, stroke, children and surgery, while revascularization surgery and RNF213 were the most common frontier topics.

Conclusions: In this study, the research trends of global scientific research on MMA over the past decade were systematically analyzed. The study can provide guidance for scholars who want to understand current trends in research in this area and new research frontiers.

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.

Endothelial Progenitor Cells Induce Angiogenesis: a Potential Mechanism Underlying Neovascularization in Encephaloduroarteriosynangiosis

Encephaloduroarteriosynangiosis (EDAS) is one of the most commonly used indirect vascular reconstruction methods. EDAS aids in the formation of collateral vessels from the extracranial to the intracranial circulation in patients with moyamoya disease (MMD). However, the underlying mechanism of collateral vessel formation is not well understood. Endothelial progenitor cells (EPCs) differentiate to form the vascular endothelial cells and play a very important role in angiogenesis. We designed this prospective clinical trial to investigate the presence of EPCs in patients with MMD and to explore the neovascularization mechanism mediated by the EPCs in EDAS. The patients who were diagnosed with MMD were recruited between February 5, 2017, and January 7, 2018. The blood samples were obtained from an antecubital vein and were analyzed using flow cytometry. EPCs were defined as CD34^brCD133⁺CD45^dimKDR⁺. All the patients enrolled in the study underwent EDAS. Cerebral arteriography was performed 6 months post-EDAS to assess the efficacy of synangiosis. The correlation between EPC count and good collateral circulation was evaluated. Among the 116 patients with MMD enrolled in this study, 73 were women and 43 were men. The average age of the patients was 33.8 ± 15.2 years. The EPC count of the patients with MMD was 0.071% ± 0.050% (expressed as percentage of the peripheral blood mononuclear cells). The EPC count in the good postoperative collateral circulation group was significantly higher (0.085% ± 0.054%) than that in the poor collateral circulation group (0.048% ± 0.034%) (P = 0.000). The age, modified Suzuki-Mugikura grade, and EPC count were significantly correlated with the good collateral circulation post-EDAS in the multivariate analysis (P = 0.018, P = 0.007, and P = 0.003, respectively). The formation of collateral vessels by EDAS is primarily driven by angiogenesis. The EPC count may be the most critical factor for collateral circulation. The therapeutic effect of EDAS is more likely to benefit younger or severe ischemic patients with MMD.

Basal and Acetazolamide Brain Perfusion SPECT in Internal Carotid Artery Stenosis

Internal carotid artery (ICA) stenosis including Moyamoya disease needs revascularization when hemodynamic insufficiency is validated. Vascular reserve impairment was the key to find the indication for endarterectomy/bypass surgery in the atherosclerotic ICA stenosis and to determine the indication, treatment effect, and prognosis in Moyamoya diseases. Vascular reserve was quantitatively assessed by 1-day split-dose I-123 IMP basal/acetazolamide SPECT in Japan or by Tc-99m HMPAO SPECT in other countries using qualitative or semi-quantitative method. We summarized the development of 1-day basal/ acetazolamide brain perfusion SPECT for ICA stenosis, both quantitative and qualitative methods, and their methodological issues regarding (1) acquisition protocol; (2) qualitative assessment, either visual or deep learning-based; (3) clinical use for atherosclerotic ICA steno-occlusive diseases and mostly Moyamoya diseases; and (4) their impact on the choice of treatment options. Trials to use CT perfusion or perfusion MRI using contrast materials or arterial spin labeling were briefly discussed in their endeavor to use basal studies alone to replace acetazolamide-challenge SPECT. Theoretical and practical issues imply that basal perfusion evaluation, no matter how much sophisticated, will not disclose vascular reserve. Acetazolamide rarely causes serious adverse reactions but included fatality, and now, we need to monitor patients closely in acetazolamide-challenge studies.

Natural Course of Moyamoya Disease in Patients With Prior Hemorrhagic Stroke

Background and Purpose- Evidence on the natural history of hemorrhagic moyamoya disease is still insufficient. We investigated the incidence of recurrent intracranial bleeding, mortality, and risk factors for rebleeding in patients with moyamoya disease. Methods- A total of 128 conservatively managed patients with hemorrhagic presentation and complete follow-up data were included. Recurrent hemorrhages during long-term follow-up were documented. Annual and cumulative incidence rate of bleeding was generated via Kaplan-Meier survival analysis, and risk factors were analyzed using logistic regression analysis. Results- The median follow-up time was 10.1 (1-27) years. During a total of 1300.7 patient-years, 47 (36.7%) patients experienced 59 occurrences of recurrent hemorrhages, rendering an average annual incidence of 4.5%. Among them, 9 patients (19.1%) died from rebleeding and 12 patients sustained severe disability (modified Rankin Scale score of ≥3). The cumulative risk of rebleeding was 7.8% at 5 years, 22.6% at 10 years, and 35.9% at 15 years. Only 4 (3.1%) patients experienced ischemic stroke, yielding an average annual incidence of 0.3%. Multivariate analysis showed that smoking (odds ratio, 4.85; P=0.04) was an independent risk factor of rebleeding. Rebleeding (hazard ratio, 11.04; P=0.02) and hypertension (hazard ratio, 4.16; P=0.04) were associated with increased mortality. Age, type of initial bleeding, digital subtraction angiography staging, family history, and coexisting cerebral aneurysms were not associated with increased risk of rebleeding. Conclusions- Rebleeding events were common and the main cause of death in patients with hemorrhagic moyamoya disease. The risk of rebleeding steadily increased during long-term follow-up. Smoking was a risk factor for rebleeding, and hypertension was associated with increased mortality.

Gene dysregulation in peripheral blood of moyamoya disease and comparison with other vascular disorders

Objective

Moyamoya disease (MMD) is a chronic occlusive cerebrovascular disease with unknown etiology, sharing many similar clinical symptoms with other vascular disorders. This study aimed to investigate gene dysregulation in peripheral blood of MMD and compare it with other vascular disorders.

Methods

Transcriptomic profiles of 12 MMD patients and 8 healthy controls were obtained using RNA sequencing. Differentially expressed genes (DEGs) were identified and several were validated by quantitative real-time PCR in independent samples. Biological pathway enrichment analysis of DEGs and deconvolution of leukocyte subsets in peripheral blood were performed. Expression profiles for other vascular diseases were downloaded from public database and consistent DEGs were calculated. Gene set enrichment analysis (GSEA) was conducted to compare gene dysregulation pattern between MMD and other vascular diseases.

Results

A total of 533 DEGs were identified for MMD. Up-regulated genes were mainly involved in extracellular matrix (ECM) organization, whereas down-regulated genes were primarily associated with inflammatory and immune responses. As for cell populations, significantly increased naïve B cells and naïve CD4 cells as well as obviously decreased resting natural killer cells were observed in peripheral blood of MMD patients. GSEA analysis indicated that only up-regulated genes of ischemic stroke and down-regulated genes of coronary artery disease and myocardial infarction were enriched in up-regulated and down-regulated genes of MMD, respectively.

Conclusion

Dysregulated genes in peripheral blood of MMD mainly played key roles in ECM organization, inflammatory and immune responses. This gene dysregulation pattern was specific compared with other vascular diseases. Besides, naïve B cells, naïve CD4 cells and resting natural killer cells were aberrantly disrupted in peripheral blood of MMD patients. These results will help elucidate the complicated pathogenic mechanism of MMD.

Cerebrovascular events after surgery versus conservative therapy for moyamoya disease: a meta-analysis

The background of this article is to determine the effect of a neurosurgical intervention in patients with moyamoya disease (MMD) on the risk of cerebrovascular events. We included studies with at least ten MMD patients in either intervention or control group which investigated cerebrovascular events during a minimal follow-up period of 1 year after neurosurgical intervention vs. conservative therapy. The primary outcome was all strokes; secondary outcome events were mortality, hemorrhagic, and ischemic stroke. Effects were evaluated for three prespecified subpopulations: adult, ischemic, and hemorrhagic moyamoya patients. We performed random-effects meta-analyses on odds ratios (ORs). We included 2,484 patients from 10 studies. The rate of all stroke was 14.1% in surgical treated compared to 30.0% in non-surgical-treated patients [pooled OR 0.38, 95%; confidence interval (CI) 0.23-0.64]. In subgroup analyses, we identified an association between surgery and all stroke in patients presenting with hemorrhagic, but not in patients with ischemic MMD. Hemorrhagic stroke during follow-up was less frequent in patients who underwent a surgical intervention, 4.6% compared to 18.6% of the conservatively treated patients (pooled OR 0.27, 95% CI 0.14-0.53). In addition, we observed a difference in mortality, 0.6% vs. 2.9% (pooled OR 0.32, 95% CI 0.13-0.77), but did not identify an association between surgical treatment and ischemic stroke (pooled OR 0.71, 95% CI 0.46-1.09). Surgical intervention in MMD is associated with a decreased risk of stroke most striking in patients presenting with hemorrhagic MMD. The relationship was present between surgical treatment and the outcome of hemorrhagic, but not ischemic stroke.

High variance of intraoperative blood pressure predicts early cerebral infarction after revascularization surgery in patients with Moyamoya disease

Few studies focused on the intraoperative blood pressure in Moyamoya disease (MMD) patients. We aimed to clarify whether or not it relates to early cerebral infarction after revascularization. We reviewed a retrospective cohort of Moyamoya disease from 2011 to 2018 in Beijing Tiantan Hospital, and patients with radiologically confirmed early postoperative infarction were included in the analysis. Controls were matched based on age, sex, and revascularization modality at a ratio of 1:5. Perioperative clinical factors and intraoperative blood pressure data were collected and analyzed. A total of 52 patients out of 1497 revascularization surgeries (3.5%) who experienced CT or MRI confirmed early postoperatively cerebral infarction, aged 38.46 ± 11.70; 26 were male (50.0%). Average real variability (ARV)-systolic blood pressure (SBP) (OR 3.29, p = 0.003), ARV-diastolic blood pressure (DBP) (OR 4.10, p = 0.005), ARV-mean arterial pressure (MAP) (OR 4.08, p = 0.004), and the maximum drops of DBP (OR 1.08, p = 0.003) and MAP (OR 1.06, p = 0.004) were associated with early postoperative infarction. In patients who experienced massive cerebral infarction, the maximum drops of DBP (OR 1.11, p = 0.004) and MAP (OR 1.11, p = 0.003) are independent risk factors, whereas ARVs of SBP (OR 3.90, p < 0.001), DBP (OR 4.69, p = 0.008), and MAP (OR 4.72, p = 0.003) are significantly associated with regional infarction. High variance of intraoperative blood pressure and drastic blood pressure decline are independent risk factors for postoperative infarction in MMD patients who underwent revascularization surgery. Maintaining stable intraoperative blood pressure is suggested to prevent early postoperative cerebral infarction in MMD patients.

Risk factors for postoperative stroke in adults patients with moyamoya disease: a systematic review with meta-analysis

Background

This systematic review and meta-analysis aimed to clarify the risk factors for postoperative stroke in adult patients with moyamoya disease (MMD).

Methods

We comprehensively searched MEDLINE/PubMed, Web of Science, and Cochrane Library for eligible published literature with regard to the risk factors and postoperative complications in adult patients with MMD. Statistical analysis was conducted using Stata version 12.0. Pooled odds ratio (OR) with 95% confidence interval (CI) were assessed for each risk factor.

Results

There were 8 studies encompassing 1649 patients who underwent surgery with MMD were selected for analysis. Preoperative ischemic event significantly increase the risk of postoperative stroke events (OR = 1.40; 95%CI = 1.02–1.92; P = 0.039). PCA involvement correlate with an increased risk of post-infarction (OR = 4.60; 95%CI = 2.61–8.11; P = 0.000). Compared to direct bypass, patients who underwent indirect bypass or combined bypass could significantly increase the risk of postoperative stroke events. (OR = 1.17; 95%CI = 1.03–1.33; p = 0.017). MMD patients with diabetes were associated with an increased risk of postoperative stroke events (OR = 4.02, 95% CI = 1.59–10.16; p = 0.003). MMD patients with hypertension, age at onset and male sex were not associated with an increased risk of postoperative stroke events (P > 0.05).

Conclusions

This systematic review and meta-analysis indicated that preoperative ischemic events, PCA involvement and diabetes were independent risk factors for postoperative stroke in MMD patients. Therefore, in order to ensure the curative effect of patients with MMD, it is very necessary to detect these risk factors and prevent postoperative complications in time.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Improving Indirect Revascularization for Effective Treatment of Adult Moyamoya Disease: A Prospective Clinical, Cerebral Angiographic, and Perfusion Study

BACKGROUND

Indirect revascularization is simple and safe, but it is not commonly used in adult moyamoya disease owing to its unreliable effect. This prospective study aimed to evaluate the effectiveness of indirect revascularization in treating adult moyamoya disease after refinement of the surgical technique and perioperative care.

METHODS

Adult patients who underwent indirect revascularization as the primary treatment for moyamoya disease between November 2013 and January 2017 were studied. The indirect revascularization procedures included encephalo-duro-arterio-synangiosis and encephalo-myo-synangiosis in the temporal region and encephalo-pericranio-synangiosis in other hypoperfusion areas. The preoperative and postoperative clinical conditions, cerebral angiography findings, and time-to-peak prolongation areas on magnetic resonance perfusion studies were assessed to evaluate the revascularization effect. Refinements of the surgical technique included the selection of surgical area based on perfusion imaging, craniotomy size, and number of affected hemispheres, along with the inclusion of a dural flap in every procedure.

RESULTS

Nineteen patients (17 females and 2 males), and a total of 31 cerebral hemispheres, were included. The mean patient age was 32.7 ± 11.4 years. After a mean follow-up of 38.6 ± 11.5 months, all patients showed clinical improvement or stabilization. Available postoperative angiography demonstrated Matsushima grade A or B in 19 of 21 hemispheres. The mean time-to-peak prolongation index of all 31 hemispheres improved from 24.09 ± 9.83% preoperatively to 12.82 ± 6.75% at 3-6 months after surgery (P < 0.001). The complication rate was 12.9%, and all complications were transient.

CONCLUSIONS

With refinements of surgical techniques and perioperative care, indirect revascularization is more reliable and can be a viable alternative treatment for adult moyamoya disease. In our cohort, outcomes were satisfactory, with mean 38.6-month follow-up.

Risk Factors Associated with Neurologic Deterioration After Combined Direct and Indirect Revascularization in Patients with Moyamoya Disease on the East Coast of China

OBJECTIVE

Neurologic deterioration is the primary distinctive complication after revascularization surgery in patients with moyamoya disease (MMD). The present study investigated the risk factors for neurologic deterioration after combined direct and indirect revascularization in patients with MMD.

METHODS

A retrospective review of 123 patients with MMD undergoing 138 combined direct and indirect revascularization procedures was performed. Demographics, clinical manifestation, medical history, neurologic deterioration complications, and relevant information of the operation were recorded.

RESULTS

There were 25 (18.12%) postoperative neurologic deterioration complications (13 reversible neurologic deficits, 9 infarctions with neurologic sequelae, and 3 hemorrhages). Preoperative multiple symptom episodes and one-staged bilateral revascularization were significantly correlated with postoperative neurologic deterioration complications (P < 0.05 and P < 0.01, respectively). The incidence rate (26.39%) of postoperative neurologic deterioration in ischemic MMDs was significantly greater than hemorrhagic MMDs (7.69%; P < 0.01) In total, 34.78% of patients with transient ischemic attack onset and 22.45% of patients with infarction onset suffered from postoperative neurologic deterioration, and there was no significant difference between them (P > 0.05). Postoperative neurologic deterioration complications had no significant correlation with sex, age at the time of surgery, type of surgical procedure, unilateral MMD or not, interval between the last attack and operation, and history of thyroid disease, hypertension, and autoimmune disease.

CONCLUSIONS

Preoperative multiple symptom episodes and one-staged bilateral revascularization are risk factors associated with postoperative neurologic deterioration in patients with MMD. Therefore, 2 unilateral revascularization procedures performed successively rather than one-staged bilateral revascularization procedures should be performed in patients with bilateral MMD.

Comparison of Therapeutic Efficacy Between Isolated Encephaloduroarteriosynangiosis and Medical Treatment in Patients with Atherosclerotic Middle Cerebral Artery Occlusion

BACKGROUND

Encephaloduroarteriosynangiosis (EDAS) as a form of indirect revascularization has been recently proposed as a potentially promising alternative for patients with intracranial atherosclerotic disease (ICAD). The object of this study was to compare the prognostic roles between isolated EDAS and medical therapy in patients with atherosclerotic middle cerebral artery occlusion (MCAO).

METHODS

From January 2014 to June 2017, 125 patients with atherosclerotic MCAO were enrolled in this prospective nonrandomized controlled cohort study. Patients who underwent EDAS (n = 60) were compared with those treated medically (n = 65). Early and late adverse events and functional outcomes including memory ability were compared between groups.

RESULTS

During 23.7 months of mean follow-up, rates of adverse events, including ischemic events in the territory of the qualifying middle cerebral artery, and death from any causes, were not significantly different in patients treated with EDAS and with medical therapy (6.7% vs. 12.3%; P = 0.285). Landmark analyses showed that at initial 6-month follow-up, there was no significant difference for adverse event rates, whereas the opposite finding was shown for the subsequent period (EDAS 1/57 [1.7%] vs. medical management 7/64 [10.9%]; P = 0.024). The P value for the interaction between time (first 6 months vs. subsequent period) was 0.044. No significant differences were found with respect to neural function status and cognitive ability.

CONCLUSIONS

In the long-term, isolated EDAS can be considered effective and safe for patients with atherosclerotic MCAO, whereas it may need additional medical therapy support in the short-term.

Surgical Treatment of Adult Moyamoya Disease

PURPOSE OF REVIEW

Moyamoya disease (MMD) is being increasingly diagnosed with the development of radiological surveillance technology and increased accessibility to medical care. Accordingly, there have been several recent reports on treatment outcomes in MMD. In this review, we summarize recent advances in surgical treatment and outcomes of adult MMD, while addressing related controversies.

RECENT FINDINGS

Recent studies suggest that revascularization surgery leads to significantly more favorable outcomes for stroke prevention, angiographic and hemodynamic changes, and clinical outcomes than does conservative treatment for adult patients with ischemic MMD. Moreover, direct revascularization methods should be considered as the first-line treatment over indirect methods, although the latter may be considered if a direct method is not possible. In cases of hemorrhagic MMD, several studies have demonstrated that surgical treatment is more effective than conservative treatment in preventing further hemorrhage. In addition to revascularization surgery, endovascular treatment is emerging as a breakthrough therapy for hemorrhagic MMD. Accumulating evidence regarding the surgical treatment of adult MMD suggests the benefit of revascularization over conservative management for both ischemic and hemorrhagic patients. However, the benefit of revascularization in asymptomatic adult MMD remains unclear.

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.

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.

The Contrast Enhancement of Intracranial Arterial Wall on High-resolution MRI and Its Clinical Relevance in Patients with Moyamoya Vasculopathy

The purpose of this study is to investigate the characteristics of intracranial vessel wall enhancement and its relationship with ischemic infarction in patients with Moyamoya vasculopathy (MMV). Forty-seven patients with MMV confirmed by angiography were enrolled in this study. The vessel wall enhancement of the distal internal carotid artery, anterior cerebral artery and middle cerebral artery was classified into eccentric and concentric patterns, as well as divided into three grades: grade 0, grade 1 and grade 2. The relationship between ischemic infarction and vessel wall enhancement was also determined. Fifty-six enhanced lesions were found in patients with (n = 25) and without acute infarction (n = 22). The incidence of lesions with grade 2 enhancement in patients with acute infarction was greater than that in those without acute infarction (p = 0.011). In addition, grade 2 enhancement of the intracranial vessel wall was significantly associated with acute ischemic infarction (Odds ratio, 26.7; 95% confidence interval: 2.8-258.2; p = 0.005). Higher-grade enhancement of the intracranial vessel wall is independently associated with acute ischemic infarction in patients with MMV. The characteristics of intracranial vessel wall enhancement may serve as a marker of its stability and provide important insight into ischemic stroke risk factors.

Clinical Features, Surgical Treatment, and Long-Term Outcome in Elderly Patients with Moyamoya Disease

OBJECTIVE

To elucidate the clinical features, surgical treatment, and long-term outcome in elderly patients with moyamoya disease (MMD).

METHODS

We retrospectively reviewed 87 elderly patients with MMD at Beijing Tiantan Hospital. Clinical features, radiologic findings, and outcomes were analyzed.

RESULTS

The mean age at diagnosis was 54.0 ± 3.7 years. Familial occurrence was 2.3%. Underlying vascular risk factors was 74.7%. Infarction was the most common symptom in elderly MMD (40.2%). Most patients presented with Suzuki stage 4 or 5 MMD (51.2%). Posterior cerebral artery involvement was observed in 22 (25.3%) patients. The incidence of postoperative infarction or hemorrhages was 6.9%. Diabetes was identified as a predictor of adverse postoperative events. During the average follow-up of 35.5 ± 22.2 months, rebleeding in patients with hemorrhagic MMD was higher than in those with ischemic MMD (P < 0.05). What's more, the rate of perfusion improvement in surgically treated patients was higher than in conservatively treated patients 3 months after discharge (P < 0.05).

CONCLUSIONS

Infarction was the most common symptom in elderly MMD. More vascular risk factors, a higher grade of Suzuki stage, fewer familial cases, and posterior cerebral artery involvement were observed in elderly patients with MMD. Diabetes was a risk factor of postoperative events for elderly patients. Hemorrhagic MMD had a higher rate of rebleeding than the ischemic type. Although surgical revascularization procedures can improve cerebral perfusion, further study is needed to determine whether surgical revascularization is effective in elderly patients or with certain techniques.

Indirect Revascularization for Non-Moyamoya Disease Anterior Circulation Arterial Steno-occlusion: Clinical Features, Surgical Treatment, and Medium-Term Outcomes in Adults

BACKGROUND

Symptomatic anterior arterial steno-occlusion is often associated with neurofunctional deficits or a high risk of recurrent stroke or both. Although both medical and endovascular treatments are useful and suitable, few studies have investigated the continued use of indirect encephaloduroarteriosynangiosis (EDAS) bypass in patients with non-moyamoya disease ischemia. We retrospectively investigated clinical features, surgical treatments, and medium-term outcomes of indirect revascularization for patients with non-moyamoya disease anterior circulation arterial steno-occlusion in China.

METHODS

EDAS without burr holes was performed in 51 adult patients with cerebral ischemic events and diagnosed nonmoyamoya anterior circulation arterial steno-occlusion. Preoperative, postoperative, and follow-up neurologic status was evaluated using the National Institutes of Health Stroke Scale; changes on angiography and perfusion-weighted magnetic resonance imaging were evaluated.

RESULTS

Unilateral EDAS was performed in 48 patients, and bilateral EDAS was performed in 3 patients. Four patients experienced complications before hospital discharge; only 23 patients underwent follow-up angiograms. Of the 51 patients, 44 (86.3%) exhibited improved muscle strength; 21 of 23 patients (91.3%) with follow-up angiography data exhibited evidence of new visible branches from the superficial temporal artery or middle meningeal artery or both. Preoperative and postoperative perfusion-weighted magnetic resonance imaging was performed for 5 patients. Despite clinical improvement in all patients, only 2 exhibited hemodynamic improvement.

CONCLUSIONS

Indirect revascularization may be safe and effective for improving blood flow to the ischemic region following nonmoyamoya anterior circulation arterial steno-occlusion, especially in patients with residual postinfarction neurologic deficits. Our study demonstrates that improvements in ischemic symptoms after EDAS correspond to neovascularization from the superficial temporal artery or middle meningeal artery in ischemic brain areas.

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.

Surgical outcomes following encephaloduroarteriosynangiosis in adult moyamoya disease associated with Type 2 diabetes

OBJECTIVE Debate exists regarding the merits and shortcomings of an indirect bypass procedure for treating adult patients with moyamoya disease (MMD). Considerable variation in neovascularization occurs among different organs in patients with diabetes mellitus. Here, the effect of encephaloduroarteriosynangiosis on MMD associated with Type 2 diabetes mellitus (T2DM) is evaluated. METHODS A retrospective and 1:2 matched case-control study was conducted in moyamoya patients with or without T2DM (n = 180). Postoperative collateral formations were graded according to the Modified Collateral Grading System that originated from the Matsushima Angiographic Stage Classification. Neurological function outcomes before and after the operation were evaluated according to the modified Rankin Scale. Univariate and multivariate logistic regression analyses were performed to determine the risk factors for clinical outcome. RESULTS There was no statistically significant difference in the constituent ratios of initial symptom and preoperative Suzuki stage between patients with and without T2DM. Progression of angiopathy around the circle of Willis was postoperatively observed in bilateral internal carotid arteries in both groups. Patients with T2DM had a higher postoperative Suzuki stage (p < 0.01) and more frequent development of collateral angiogenesis germinating from the external carotid after indirect revascularization procedures in the surgical cerebral hemisphere (82.7% vs 72.2%; p < 0.05). The extent of postoperative collateral formation in patients with diabetes mellitus was significantly higher (p < 0.01). Postoperative clinical improvement in the diabetes group was more common after revascularization procedures (p < 0.05), and the diabetes group had lower modified Rankin Scale scores (p < 0.05) in comparison with the nondiabetes group. Late postoperative stroke and posterior cerebral artery involvement were identified as predictors of unfavorable clinical outcome in both groups, while T2DM was associated with a favorable clinical outcome. CONCLUSIONS Encephaloduroarteriosynangiosis is an efficacious treatment for adult patients with MMD. Patients with T2DM could achieve better collateral circulation and clinical improvement following surgery.

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.

First autopsy analysis of a neovascularized arterial network induced by indirect bypass surgery for moyamoya disease: case report

The object of this study was to analyze the pathology of collateral vessels newly induced by indirect bypass surgery for moyamoya disease (MMD). An autopsy analysis was conducted on a 39-year-old woman with MMD who had died of a brainstem infarction. The patient had undergone bilateral indirect bypass surgeries 22 years earlier. Sufficient revascularization via bilateral external carotid arterial systems was confirmed by cerebral angiography before her death. Macroscopic observation of the operative areas revealed countless meandering vessels on the internal surface of the dura mater connected with small vessels on the brain surface and in the subpial brain tissue. Notably, microscopic analysis of these vessels revealed the characteristic 3-layer structure of an arterial wall. This autopsy analysis was the first to confirm that indirect bypass surgery had induced the formation of a new arterial network (arteriogenesis) and that this network had been maintained for more than 20 years to compensate for the chronic cerebral ischemia caused by the MMD.

Clinical Features, Surgical Treatment, and Long-Term Outcome in Pediatric Patients with Moyamoya Disease in China

Background: There was few detailed demographic and clinical data about Chinese patients with moyamoya disease. Here we describe the clinical features, surgical treatment, and long-term outcome of pediatric patients with moyamoya disease at a single institution in China. Methods: Our cohort included 288 pediatric patients with moyamoya disease. The demographic and clinical characteristics were obtained by retrospective chart review and long-term outcome was evaluated using the stroke status. Univariate and multivariate logistic regression analyses were performed to determine the risk factors for clinical outcome. The risk of subsequent stroke was determined using the Kaplan-Meier method. Results: The median age for the onset of symptoms was 8.0 years. The ratio of female to male patients was 1:1. Familial occurrence of moyamoya disease was 9.4%. The incidence of postoperative complications was 4.2%. Postoperative ischemic events were identified as predictors of unfavorable clinical outcome, while older age of symptom onset was associated with a favorable clinical outcome. The Kaplan-Meier estimate stroke risk was 5% in the first 2 years, and the 5-year-Kaplan-Meier risk of stroke was 9% after surgery for all patients treated with surgical revascularization. Overall, 86% of patients had an independent life with no significant disability. Conclusion: This long-term survey demonstrated that most surgically treated pediatric patients with MMD maintain good outcomes. Our results indicate that an early diagnosis and active intervention before the establishment of irreversible hemodynamic change are essential to achieve a favorable clinical outcome.

Recent progress in hemorrhagic moyamoya disease

Moyamoya disease (MMD) is a chronic progressive cerebrovascular disease, which can be divided into three types: ischemic, hemorrhagic, and asymptomatic. Hemorrhagic MMD has attracted considerable attention due to its distinctive imaging features and the controversy over the treatment. This report presents a comprehensive review of the literature on hemorrhagic MMD, focusing on the epidemiological characteristics, etiology and pathogenesis, imaging features, predictors of hemorrhage, and treatment options and their efficacy of hemorrhagic MMD. Hemorrhagic MMD mainly occurs in adult patients in Asian countries, and many factors may contribute to the etiology and development of this disease. Hemorrhagic MMD has two major imaging features: the dilatation and abnormal branching of anterior choroidal artery or posterior communicating artery, and multiple microbleeds, which may predict subsequent hemorrhage. The treatment for hemorrhagic MMD is not standardized, and large sample prospective randomized clinical trials may help to determine which method is better. In hemorrhagic MMD patients, more attention should be paid to cognitive function and quality of life, and these assessments should be included in the evaluation of effectiveness of treatment modalities.

Moyamoya syndrome associated with Graves' disease: a case series study

OBJECTIVE

The aim of this study was to describe the clinical and radiological findings of patients with moyamoya syndrome and Graves' disease. Possible mechanisms predisposing these individuals to ischemic stroke are discussed.

METHODS

We retrospectively analyzed 12 consecutive patients with both moyamoya syndrome and Graves' disease. Moyamoya vasculopathy was diagnosed by digital subtract angiography or magnetic resonance angiography (MRA). The clinical characteristics, laboratory data, vascular radiological characteristics and outcome were reported.

RESULTS

All patients were female and mean age was 33.33±12.65 years. Stenosis or occlusion of bilateral terminal internal carotid artery and/or proximal anterior/middle cerebral arteries was found in nine patients. Among them, three patients displayed asymmetrical stenosis. In addition, there were three patients with probable unilateral moamoya syndrome. Eleven patients presented with ischemic stroke and/or transient ischemic attack (TIA) and one with dizziness. Thyroid function tests demonstrated elevated thyroid hormone levels and suppressed thyroid stimulating hormone levels in all the patients with ischemic events. All patients received anti-thyroid therapy and two had recurrent ischemic attack after drug withdrawal.

CONCLUSIONS

Moyamoya syndrome associated Graves' disease often presented with asymmetric stenosis or occlusion. We hypothesize cerebrovascular hemodynamic changes due to thyrotoxicosis contribute to the ischemic events.