Results of Conservative Follow-up or Surgical Treatment of Moyamoya Patients Who Present without Hemorrhage, Transient Ischemic Attack, or Stroke

[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.

Ischemic patterns and their angiographic risk factors in adult patients with moyamoya disease

OBJECTIVE

The present study aims to determine whether angiographic differences increase the risk of ischemic pattern among adult patients with moyamoya disease (MMD).

METHODS

From January 2020 to December 2021, we retrospectively enrolled 123 ischemic or asymptomatic adult patients diagnosed as MMD. Angiographic changes including Suzuki stage, moyamoya vessels, anterior choroidal artery (AChoA) dilatation, lenticulostriate artery (LSA) dilatation, posterior communicating artery (PcomA) dilatation, and posterior cerebral artery (PCA) involvement were evaluated for all patients.

RESULTS

Among the 123 participants, 35 ischemic patients and 88 asymptomatic patients were analyzed. There was no significant difference of Suzuki stage, AChoA dilatation, LSA dilatation, and PcomA dilatation between ischemic group and asymptomatic group. The grading of moyamoya vessels differed significantly but was not a factor associated with ischemic pattern after adjusting multiple related confounders. However, the frequency of PCA steno-occlusive changes in ischemic patients was statistically higher than that in asymptomatic patients (54.3% vs 34.1%, p = 0.039). Furthermore, PCA involvement was a risk factor associated with ischemic form and remained statistically significant after the multivariate adjustment (p = 0.033, 95% CI 1.092-8.310).

INTERPRETATION

PCA involvement is closely related to the presentation of ischemic stroke but other angiographic features had no association with ischemic pattern in adult MMD.

Association of Bypass Surgery and Mortality in Moyamoya Disease

Background Patients with moyamoya disease (MMD) have a high risk of stroke or death. We investigated whether extracranial to intracranial bypass surgery can reduce mortality by preventing strokes in patients with MMD. Methods and Results This nationwide retrospective cohort study encompassed patients with MMD registered under the Rare Intractable Diseases program via the Relieved Co-Payment Policy between 2006 and 2019, using the Korean National Health Insurance Service database. Following a 4-year washout period, landmark analyses were employed to assess mortality and stroke occurrence between the bypass surgery group and the nonsurgical control group at specific time points postindex date (1 month and 3, 6, 12, and 36 months). The study included 18 480 patients with MMD (mean age, 40.7 years; male to female ratio, 1:1.86) with a median follow-up of 5.6 years (interquartile range, 2.5-9.3; mean, 6.1 years [SD, 4.0 years]). During 111 775 person-years of follow-up, 265 patients in the bypass surgery group and 1144 patients in the nonsurgical control group died (incidence mortality rate of 618.1 events versus 1660.3 events, respectively, per 105 person-years). The overall adjusted hazard ratio (HR) revealed significantly lower all-cause mortality in the bypass surgery group from the 36-month landmark time point, for any stroke mortality from 3- and 6-month landmark time points, and for hemorrhagic stroke mortality from the 6-month landmark time point. Furthermore, the overall adjusted HRs for hemorrhagic stroke occurrence were beneficially maintained from all 5 landmark time points in the bypass surgery group. Conclusions Bypass surgery in patients with MMD was associated with a lower risk of all-cause and hemorrhagic stroke mortality and hemorrhagic stroke occurrence compared with nonsurgical control.

Five-Year Stroke Risk and Its Predictors in Asymptomatic Moyamoya Disease: Asymptomatic Moyamoya Registry (AMORE)

BACKGROUND

Long-term outcomes are unknown in patients with asymptomatic moyamoya disease. In this report, we aimed to clarify their 5-year risk of stroke and its predictors.

METHODS

We are conducting a multicenter, prospective cohort study (Asymptomatic Moyamoya Registry) in Japan. Participants were eligible if they were 20 to 70 years, had bilateral or unilateral moyamoya disease, experienced no episodes suggestive of TIA and stroke; and were functionally independent (modified Rankin Scale score 0-1). Demographic and radiological information was collected at enrollment. In this study, they are still followed up for 10 years. In this interim analysis, we defined the primary end point as a stroke occurring during a 5-year follow-up period. Independent predictors for stroke were also determined, using a stratification analysis method.

RESULTS

Between 2012 and 2015, we enrolled 109 patients, of whom 103 patients with 182 involved hemispheres completed the 5-year follow-up. According to the findings on DSA and MRA, 143 hemispheres were judged as moyamoya disease and 39 hemispheres as questionable manifestations (isolated middle cerebral artery stenosis). The patients with questionable hemispheres were significantly older, more often male, and more frequently had hypertension than those with moyamoya hemisphere. Moyamoya hemispheres developed 7 strokes, including 6 hemorrhagic and 1 ischemic stroke, during the first 5 years. The annual risk of stroke was 1.4% per person, 0.8% per hemisphere, and 1.0% per moyamoya hemisphere. Independent predictor for stroke was Grade-2 choroidal anastomosis (hazard ratio, 5.05 [95% CI, 1.24-20.6]; P=0.023). Furthermore, microbleeds (hazard ratio, 4.89 [95% CI, 1.13-21.3]; P=0.0342) and Grade-2 choroidal anastomosis (hazard ratio, 7.05 [95% CI, 1.62-30.7]; P=0.0093) significantly predicted hemorrhagic stroke. No questionable hemispheres developed any stroke.

CONCLUSIONS

The hemispheres with asymptomatic moyamoya disease may carry a 1.0% annual risk of stroke during the first 5 years, the majority of which are hemorrhagic stroke. Grade-2 choroidal anastomosis may predict stroke, and the microbleeds and Grade-2 choroidal anastomosis may carry the risk for hemorrhagic stroke.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: UMIN000006640.

Computational Modelling of Cerebral Blood Flow Rate at Different Stages of Moyamoya Disease in Adults and Children

Moyamoya disease is a cerebrovascular disorder which causes a decrease in the cerebral blood flow rate. In this study, a lumped parameter model describing the pressures and flow rates in the heart chambers, circulatory system, and cerebral circulation with the main arteries in the circle of Willis, pial circulation, cerebral capillaries, and veins was used to simulate Moyamoya disease with and without coarctation of the aorta in adults and children. Cerebral blood flow rates were 724 mL/min and 1072 mL/min in the healthy adult and child cardiovascular system models. The cerebral blood flow rates in the adult and child cardiovascular system models simulating Moyamoya disease were 676 mL/min and 1007 mL/min in stage 1, 627 mL/min and 892 mL/min in stage 2, 571 mL/min and 831 in stage 3, and 444 and 537 mL/min in stage 4. The cerebral blood flow rates were 926 mL/min and 1421 mL/min in the adult and child cardiovascular system models simulating coarctation of the aorta. Furthermore, the cerebral blood flow rates in the adult and child cardiovascular system model simulating Moyamoya disease with coarctation of the aorta were 867 mL/min and 1341 mL/min in stage 1, 806 mL/min and 1197 mL/min in stage 2, 735 mL/min and 1121 in stage 3, and 576 and 741 mL/min in stage 4. The numerical model utilised in this study can simulate the advancing stages of Moyamoya disease and evaluate the associated risks with Moyamoya disease.

Asymptomatic Moyamoya Disease in a North American Adult Cohort

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Distinct Clinical and Radiographic Phenotypes in Pediatric Patients With Moyamoya

BACKGROUND

Given the expanding evidence of clinico-radiological differences between moyamoya disease (MMD) and moyamoya syndrome (MMS), we compared the clinical and radiographic features of childhood MMD and MMS to identify predictors of ischemic event recurrence.

METHODS

We reviewed a pediatric moyamoya cohort followed between 2003 and 2019. Clinical and radiographic characteristics at diagnosis and follow-up were abstracted. Comparisons between MMD and MMS as well as between MMD and two MMS subgroups (neurofibromatosis [MMS-NF1] and sickle cell disease [MMS-SCD]) were performed.

RESULTS

A total of 111 patients were identified. Patients with MMD presented commonly with transient ischemic attacks (TIAs) (35 % MMD versus 13% MMS-NF1 versus 9.5% MMS-SCD; P = 0.047). Symptomatic stroke presentation (MMD 37% versus MMS-NF1 4% versus 33%; P = 0.0147) and bilateral disease at diagnosis (MMD 73% versus MMS-NF1 22 % versus MMS-SCD 67%; P = 0.0002) were uncommon in MMS-NF1. TIA recurrence was common in MMD (hazard ratio 2.86; P = 0.001). The ivy sign was absent on neuroimaging in a majority of patients with MMS-SCD (MMD 67% versus MMS-NF1 52% versus MMS-SCD 9.5%; P = 0.0002). Predictors of poor motor outcome included early age at diagnosis (odds ratio [OR] 8.45; P = 0.0014), symptomatic stroke presentation (OR 6.6; P = 0.019), and advanced Suzuki stage (OR 3.59; P = 0.019).

CONCLUSIONS

Moyamoya exhibits different phenotypes based on underlying etiologies. Frequent TIAs is a common phenotype of MMD and symptomatic stroke presentation a common feature of MMD and MMS-SCD, whereas unilateral disease and low infarct burden are common in MMS-NF1. In addition, absence of ivy sign is a common phenotype in MMS-SCD.

Comparison of Operative and Conservative Treatment for Asymptomatic Moyamoya Disease: Preliminary Experience in Small Retrospective Series

OBJECTIVE

The best management of asymptomatic moyamoya disease (MMD) remains controversial. In this study, the authors aimed to explore an experience for treatment modality for asymptomatic MMD.

METHODS

The authors retrospectively reviewed a total of 23 patients (age range 30-58 years) with asymptomatic MMD during the past 5 years at their institutions. The patients were divided into 2 groups: The surgical group included 11 patients, and the conservative group included 12 patients. The demographic, radiologic, and clinical findings of the patients were evaluated. At follow-up over 13-65 months, the future clinical and radiologic progression events were evaluated.

RESULTS

During the follow-up period, 3 patients suffered from future clinical progression events in the conservative group: 1 experienced stroke, and 2 experienced transient ischemic attack. Among the patients in the surgical group, only 1 experienced transient ischemic attack. Kaplan-Meier analysis showed that patients undergoing surgeries had longer clinical progression-free survival times compared with patients in the conservative group (P = 0.002).

CONCLUSIONS

Surgical treatment may be an alternative choice for patients with asymptomatic MMD. However, the best strategy for asymptomatic MMD in order to reduce future cerebrovascular risks still needs to be further explored.

Moyamoya: An Update and Review

This article is a clinical review of Moyamoya disease (MMD) and Moyamoya syndrome (MMS). We review the incidence, epidemiology, pathology, historical context, clinical and radiographic findings, diagnostic imaging modalities, radiographic grading systems, the effectiveness of medical, interventional, and surgical treatment, and some of the nuances of surgical treatment options. This article will help pediatricians, neurologists, neurosurgeons, and other clinical practitioners who are involved in caring for patients with this rare clinical entity. MMD is an intrinsic primary disease process that causes bilateral progressive stenosis of the anterior intracranial circulation with the involvement of the proximal portions of the intracranial internal carotid artery (ICA) extending to involve the proximal portions of the anterior cerebral artery (ACA) and middle cerebral artery (MCA); posterior circulation involvement is very rare. This causes a compensatory response where large numbers of smaller vessels such as the lenticulostriate arteries begin to enlarge and proliferate, which gives the angiographic appearance of a "Puff of Smoke", which is translated into Japanese as "Moyamoya". MMS is a secondary process that occurs in response to another underlying pathological process that causes stenosis of intracranial blood vessels, such as radiation. For example, an external source of radiation causes stenosis of the ICA with a compensatory response of smaller blood vessels, which then enlarge and proliferate in response and has the same "Puff of Smoke" appearance on the diagnostic cerebral angiogram (DCA). Histological findings include an irregular internal elastic lamina with luminal narrowing, hyperplasia of the tunica media, and intimal thickening with vacuolar degeneration in smooth muscle cells in the tunica media. Compensation for diminishing blood supply occurs through angiogenesis, which causes the proliferation and enlargement of smaller collateral blood vessels to increase blood supply to under-perfused areas of the brain. MMD is rare in the United States, with just 0.086 newly diagnosed cases per 100,000 individuals per year, which is approximately one per million new cases annually. Risk factors for MMD include Eastern Asian ancestry and predisposing conditions such as neurofibromatosis and Down's syndrome. Clinically, patients often present with stroke signs and symptoms from cerebral ischemia. The proliferation of collateral blood vessels within the basal ganglia can produce movement disorders. Catheter-based DCA is the current gold standard for obtaining a diagnosis. CT perfusion allows preoperative identification of ischemic vascular territories, which may be amenable to surgical intervention. MRI enables rapid detection of acute ischemic stroke using diffusion-weighted Imaging (DWI) and apparent diffusion coefficient (ADC) sequences to assess for any diffusion restriction. Non-contrast CT of the head is used to rule out acute hemorrhage in the presentation of a progressive neurological deficit. The treatment option for Moyamoya is generally surgical; medical treatment has failed to halt disease progression and neuro-interventional techniques such as attempted stenting of stenosed vessels have failed. Surgical options include direct and indirect cerebrovascular bypass.

Characteristics of cognitive impairment in adult asymptomatic moyamoya disease

Background

Cognitive impairment in adult moyamoya disease (MMD) is thought to be the result of ischemic stroke; however, the presence and extent of cognitive decline in asymptomatic patients is unclear.

Methods

After classification using T2-weighted fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI), a total of 19 MMD patients with a history of cerebral infarction, 21 asymptomatic MMD patients, and 20 healthy controls matched for age, sex, and years of education were prospectively included in this study. A detailed neuropsychological evaluation of two moyamoya subgroups and normal controls was conducted.

Results

Asymptomatic patients showed varying degrees of decline in intelligence (Raven’s Standard Progressive Matrices, P = 0.001), spatial imagination (mental rotation, P = 0.014), working memory (verbal working memory-backward digit span, P = 0.011), and computational ability (simple subtraction, P = 0.014; complex subtraction, P < 0.001) compared with normal controls. MMD patients with cerebral infarction had more severe impairment in complex arithmetic (P = 0.027) and word short-term memory (P = 0.01) than those without symptoms.

Conclusion

In asymptomatic MMD patients, a variety of cognitive impairment precedes the onset of clinical symptoms such as cerebral infarction, which may be a long-term complication of conservative treatment.

[Modern trends in diagnosis and surgical treatment of moyamoya disease]

This review is devoted to moyamoya disease. It is a rare chronic steno-occlusive cerebrovascular disease. However, moyamoya disease is increasingly diagnosed by neurosurgeons in our country. Unlike atherosclerotic lesions of cerebral arteries, pathogenesis and course of this disease are much more complex and variable. Therefore, specialists often have certain difficulties in diagnosis, management and treatment of these patients. To date, a large number of surgical interventions have been proposed for the treatment of moyamoya disease. Revascularization approaches include direct procedures (extra-intracranial microanastomoses), indirect methods (synangioses) and combined revascularization. The purpose of the review is to systematize current literature data on the pathogenesis, diagnosis, clinical patterns and surgical treatment of patients with moyamoya disease. results Outcomes of surgical revascularization and the role of its various components in combined approach are under particular attention.

Ischemic sequelae and other vascular diseases

Although pediatric stroke is associated with higher survival rates compared with adult stroke, a substantial body of evidence indicates significant neuropsychologic morbidity in pediatric stroke survivors. Neuroplasticity does not guarantee good outcome in children. The general trends observed in the literature are reviewed as is the profile observed in common causes of pediatric stroke: congenital heart disease, moyamoya disease, and sickle cell disease. The neuropsychologic profile of pediatric stroke patients is heterogeneous due to the multiplicity of associated causes. Stroke in early infancy and large strokes are associated with cognitive impairment while more limited disorders, such as phasic deficit, are observed in childhood stroke. Executive dysfunction is common in pediatric stroke, but social interaction skills are usually preserved. Congenital heart disease and sickle cell disease are associated with global neuropsychologic dysfunction while cognition is usually preserved in moyamoya. Executive dysregulation is instead more frequently reported in this population. Further study of maladaptive processes after pediatric stroke will allow identification of predictors of functional and neuropsychologic outcomes and permit personalization of care.

Meta-Analysis of Prognosis of Different Treatments for Symptomatic Moyamoya Disease

OBJECTIVE

The purpose of this study was to evaluate the efficacy of surgical revascularization versus conservative treatment and different surgical modalities, in order to provide evidence for the patient with moyamoya disease (MMD) to choose the appropriate treatment.

METHODS

We comprehensively searched PubMed, Embase, Web of Science, and the Cochrane Library for articles published regarding MMD treatment. If the I² value, which evaluated the heterogeneity, was <50%, a fixed-effect model was used; if not, a random effect model was applied.

RESULTS

Twenty-seven articles were included in the meta-analysis. The surgery group is more advantageous in reducing the risk of future stroke events than conservative treatment in MMD patients (odds ratio [OR] 0.26, 95% confidence interval [CI] 0.20-0.33, P < 0.001). In addition, the surgical group also had an advantage in terms of increased cerebral perfusion (OR 7.16, 95% CI 3.28-15.64, P < 0.001) and death due to rebleeding (OR 0.27, 95% CI 0.10-0.72, P < 0.01). Direct surgery showed a significant efficacy over indirect surgery (OR 2.03, 95% CI 1.32-3.13, P < 0.01). No obvious difference was found between the direct and indirect bypass subset (OR 0.76, 95% CI 0.51-1.14, P = 0.185). Angiographic results in patients undergoing direct bypass surgery are more pronounced (OR 0.20, 95% CI 0.06-0.67, P < 0.01).

CONCLUSIONS

In patients with symptomatic moyamoya disease, bypass surgery is more effective than conservative treatment to prevent future strokes. In surgical patients, direct bypass seems to reduce the risk of stroke more than an indirect bypass.

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.