Recent advances in moyamoya disease: pathophysiology and treatment

Moyamoya disease in an adolescent with subarachnoid hemorrhage: a case report

PURPOSE/AIM OF THE STUDY

This study aims to present a case of Moyamoya disease (MMD) in an adolescent who experienced a subarachnoid hemorrhage (SAH). The purpose is to underscore the importance of considering MMD as a potential cause of SAH in adolescents, particularly in the absence of common causes such as trauma or aneurysmal rupture. The case further highlights the significance of early identification and appropriate management to prevent further complications and improve patient outcomes.

MATERIALS AND METHODS

The diagnosis was initially based on findings from a CT angiography and later confirmed through magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI).

RESULTS

The case study demonstrates the effectiveness of utilizing MRA and MRI in diagnosing MMD in adolescents. It emphasizes the challenges in areas with limited resources where advanced imaging techniques like digital subtraction angiography (DSA) may not be readily accessible or affordable. The gold standard for MMD diagnosis, DSA, is acknowledged, but the study underscores the importance of alternative imaging methods in resource-constrained settings.

CONCLUSION

In conclusion, this case underscores the importance of considering Moyamoya disease as a potential etiology for subarachnoid hemorrhage in adolescents, particularly when common causes are absent. The study highlights the crucial role of MRA and MRI in the diagnosis of MMD, emphasizing their significance in areas with limited resources. Early identification and appropriate management are essential for preventing complications and improving patient outcomes, acknowledging the challenges associated with the accessibility of gold standard diagnostic techniques in certain settings.

Low hemoglobin is associated with postoperative cerebral infarction in moyamoya disease: development of a predictive model based on low hemoglobin

Background

Anemia is considered a risk factor for cardiovascular disease. However, there is little evidence regarding the relationship between hemoglobin (HB) and cerebral infarction after revascularization in patients with moyamoya disease (MMD). This study aimed to explore the relationship between postoperative cerebral infarction and HB in patients with MMD and to establish a predictive model.

Methods

Demographic information and different HB levels (the preoperative and postoperative HB, highest and lowest HB, and mean HB during hospitalization) of 112 patients with MMD were collected, of which 11 had cerebral infarction after revascularization.

Results

In the binomial logistic regression analysis, low HB levels were an independent risk factor for cerebral infarction after revascularization, which also led to a worse long-term prognosis in patients with MMD. The risk factors, including Pre-HB, Post-HB, type of MMD, and hypertension (HTN), were incorporated into the receiver operating characteristic curve, which yielded an area under the curve (AUC) of 0.83.

Conclusion

The prediction model was visualized using a nomogram, and a clinical decision curve was drawn to evaluate the net benefit of clinical decisions.

Neuropsychological Test Performance Differentiates Subgroups of Individuals With Adult Moyamoya Disease: A Cross-Sectional Clinical Study

BACKGROUND AND OBJECTIVES

Moyamoya disease (MMD) is a rare noninflammatory disorder involving progressive intracranial vasculopathy and impaired cerebral blood flow in the anterior circulation, resulting in stroke and cognitive impairment. We aimed to characterize cognitive impairment and the possible predictive value of sociodemographic and clinical characteristics of adults with MMD.

METHODS

This cross-sectional study examined neurocognitive performance in a group of 42 consecutive adult patients (mean age = 40.52 years; 69% female) referred for a presurgical neuropsychological evaluation. Neuropsychological functioning was assessed with a comprehensive battery, and cognitive dysfunction was defined as 1.5 SDs below the mean. Neurocognitive performance correlated with clinical/demographic characteristics and disease markers.

RESULTS

Most patients (91%) had a history of stroke, and 45% had cognitive deficits, most notably on measures of attention/speed (48%), executive functioning (47%), visuoconstruction (41%), and memory (31%-54%). Only higher educational attainment and poor collateral blood flow in the right hemisphere differentiated cognitively impaired (n = 19) and intact groups (n = 23), and MMD-related characteristics (eg, disease duration, stroke history) did not differentiate the 2 groups.

CONCLUSION

Consistent with previous work, frontal-subcortical cognitive deficits (eg, deficits in mental speed, attention, executive functioning) were found in nearly half of patients with MMD and better cognitive performance was associated with factors related to cognitive reserve. Angiographic metrics of disease burden (eg, Suzuki rating, collateral flow) and hemodynamic reserve were not consistently associated with poorer cognitive outcomes, suggesting that cognition is a crucial independent factor to assess in MMD and has relevance for treatment planning and functional status.

Moyamoya Disease: Advances in Diagnosis, Treatment, and Surgical Interventions

Moyamoya disease (MMD) is a rare cerebrovascular disorder characterized by progressive narrowing of the brain's arteries, leading to an increased risk of stroke. The primary susceptibility gene, RNF213, has been identified in individuals of East Asian descent, contributing to ongoing research into potential therapeutic targets. The distinction between idiopathic MMD and secondary forms, such as Moyamoya syndrome (MMS), is discussed, focusing on associated conditions and risk factors. Surgical revascularization emerges as the mainstay of treatment, with direct, indirect, and combination bypass procedures explored. The review delves into advancements in imaging technology for diagnosis and treatment planning, emphasizing non-invasive magnetic resonance examination's role in identifying asymptomatic patients. Additionally, insights into anesthetic care and therapeutic approaches underscore the evolving understanding of this complex disease. The presented information aims to contribute to the ongoing dialogue surrounding MMD, providing a valuable resource for clinicians and researchers.

Upregulated Cytoskeletal Proteins Promote Pathological Angiogenesis in Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is a rare progressive vascular disease that leads to intracranial internal carotid artery stenosis and eventual occlusion. However, its pathogenesis remains unclear. The purpose of this study is to explore the role of abnormally expressed proteins in the pathogenesis of MMD.

METHODS

Data-independent acquisition mass spectrometry identifies the differentially expressed proteins in MMD serum by detecting the serum from 60 patients with MMD and 20 health controls. The differentially expressed proteins were validated using enzyme linked immunosorbent assays. Immunofluorescence for superficial temporal artery and middle cerebral artery specimens was used to explore the morphological changes of vascular wall in MMD. In vitro experiments were used to explore the changes and mechanisms of differentially expressed proteins on endothelial cells.

RESULTS

Proteomic analysis showed that a total of 14 726 peptides and 1555 proteins were quantified by mass spectrometry data. FLNA (filamin A) and ZYX (zyxin) proteins were significantly higher in MMD serum compared with those in health controls (Log2FC >2.9 and >2.8, respectively). Immunofluorescence revealed an intimal hyperplasia in superficial temporal artery and middle cerebral artery specimens of MMD. FLNA and ZYX proteins increased the proportion of endothelial cells in S phase and promoted their proliferation, angiogenesis, and cytoskeleton enlargement. Mechanistic studies revealed that AKT (serine/threonine kinase)/GSK-3β (glycogen synthase kinase 3β)/β-catenin signaling pathway plays a major role in these FLNA- and ZYX-induced changes in endothelial cells.

CONCLUSIONS

This study provides proteomic data on a large sample size of MMD. The differential expression of FLNA and ZYX in patient with MMD and following in vitro experiments suggest that these upregulated proteins are related to the pathology of cerebrovascular intimal hyperplasia in MMD and are involved in MMD pathogenesis, with diagnostic and therapeutic ramifications.

Anesthesia Depresses Cerebrovascular Reactivity to Acetazolamide in Pediatric Moyamoya Vasculopathy

Measurements of cerebrovascular reactivity (CVR) are essential for treatment decisions in moyamoya vasculopathy (MMV). Since MMV patients are often young or cognitively impaired, anesthesia is commonly used to limit motion artifacts. Our aim was to investigate the effect of anesthesia on the CVR in pediatric MMV. We compared the CVR with multidelay-ASL and BOLD MRI, using acetazolamide as a vascular stimulus, in all awake and anesthesia pediatric MMV scans at our institution. Since a heterogeneity in disease and treatment influences the CVR, we focused on the (unaffected) cerebellum. Ten awake and nine anesthetized patients were included. The post-acetazolamide CBF and ASL-CVR were significantly lower in anesthesia patients (47.1 ± 15.4 vs. 61.4 ± 12.1, p = 0.04; 12.3 ± 8.4 vs. 23.7 ± 12.2 mL/100 g/min, p = 0.03, respectively). The final BOLD-CVR increase (0.39 ± 0.58 vs. 3.6 ± 1.2% BOLD-change (mean/SD), p < 0.0001), maximum slope of increase (0.0050 ± 0.0040%/s vs. 0.017 ± 0.0059%, p < 0.0001), and time to maximum BOLD-increase (~463 ± 136 and ~697 ± 144 s, p = 0.0028) were all significantly lower in the anesthesia group. We conclude that the response to acetazolamide is distinctively different between awake and anesthetized MMV patients, and we hypothesize that these findings can also apply to other diseases and methods of measuring CVR under anesthesia. Considering that treatment decisions heavily depend on CVR status, caution is warranted when assessing CVR under anesthesia.

Vessel wall enhancement as a predictor of arterial stenosis progression and poor outcomes in moyamoya disease

OBJECTIVES

This study aimed to determine the association between vessel wall enhancement and progression of arterial stenosis and clinical outcomes in patients with moyamoya (MMD) using high-resolution magnetic resonance (HRMR) vessel wall imaging.

METHODS

Consecutive participants diagnosed with MMD were prospectively recruited and underwent HRMR at baseline and during follow-up, which had an interval period of ≥ 6 months and were clinically followed up for ≤ 24 months to record the occurrence of ischemic stroke. The relationship between vessel wall enhancement and arterial stenosis progression and stroke occurrence was evaluated.

RESULTS

HRMR vessel wall imaging was used to identify 309 stenotic lesions at the internal carotid artery (ICA) in 170 participants (mean age: 37.7 ± 11.3 years old, male: 44.1%). The baseline presence (adjusted odds ratio [aOR] = 3.57, 95% CI = 1.97-6.44, p < 0.001) and progression (aOR = 2.96, 95% CI = 1.29-6.80, p = 0.010) of vessel wall enhancement and middle cerebral artery (MCA) involvement (aOR = 4.98, 95% CI = 1.50-16.52, p = 0.009) were significantly associated with rapid progression of arterial stenosis. Furthermore, vessel wall enhancement (adjusted HR = 3.59, 95% CI = 1.33-9.70, p = 0.011) and rapid progression of arterial stenosis (adjusted HR = 4.52, 95% CI = 1.48-13.81, p = 0.008) were correlated with future stroke occurrence.

CONCLUSION

The baseline presence of vessel wall enhancement was associated with rapid progression of arterial stenosis and increased risk for stroke in MMD patients. Our findings suggest that vessel wall enhancement may serve as a predictor of disease progression and poor outcomes in MMD.

KEY POINTS

• The baseline presence of vessel wall enhancement was significantly associated with the rapid progression of arterial stenosis. • The baseline presence of vessel wall enhancement and rapid progression of arterial stenosis were both correlated with increased risk for future occurrence of stroke. • Our findings suggest that vessel wall enhancement may serve as a predictor of rapid progression of arterial stenosis and poor outcomes in MMD patients.

Circulating Inflammatory Cytokine Associated with Poor Prognosis in Moyamoya Disease: A Prospective Cohort Study

Inflammation is a key factor in the development of moyamoya disease. However, the cytokine distribution in moyamoya disease and its impact on prognosis remain unclear. A total of 204 patients with moyamoya disease were enrolled in this study. The peripheral blood was analyzed for baseline data and cytokines, which included IL-6, IL-1β, IL-2R, IL-8, and TNF-α. Patients with the RNF213 mutation and those without the mutation were compared in terms of their differences in cytokines. A mRS score ≥2 was defined as a poor prognosis, and a mRS score <2 was described as a good prognosis, and differences in cytokines were compared between the two groups. Regression analysis was performed to identify markers affecting prognosis. TNF-α and IL-6 levels were higher in the group without the RNF213 mutation compared to the mutation group. Multivariate stepwise regression analysis indicated that the G3 subgroup of IL-6 and the G4 subgroup of TNF-α were the independent risk factors for adverse prognosis in adults with moyamoya disease (OR 3.678, 95% CI [1.491, 9.074], p = 0.005; OR 2.996, 95% CI [1.180, 7.610], p = 0.021). IL-6 and TNF-α were associated with poor prognosis in adult patients with moyamoya disease.

The profile of cognitive impairment and hemodynamic compromise in moyamoya: a single-center prospective cohort study

OBJECTIVE

Patients with moyamoya vasculopathy often experience cognitive impairments. In this prospective single-center study, the authors investigated the profile of neurocognitive impairment and its relation with the severity of ischemic brain lesions and hemodynamic compromise.

METHODS

Patients treated in a Dutch tertiary referral center were prospectively included. All patients underwent standardized neuropsychological evaluation, MRI, digital subtraction angiography, and [15O]H2O-PET (to measure cerebrovascular reactivity [CVR]). The authors determined z-scores for 7 cognitive domains and the proportion of patients with cognitive impairment (z-score < -1.5 SD in at least one domain). The authors explored associations between patient characteristics, imaging and CVR findings, and cognitive scores per domain by using multivariable linear regression and Bayesian regression analysis.

RESULTS

A total of 40 patients (22 children; 75% females) were included. The median age for children was 9 years (range 1-16 years); for adults it was 39 years (range 19-53 years). Thirty patients (75%) had an infarction, and 31 patients (78%) had impaired CVR (steal phenomenon). Six of 7 cognitive domains scored below the population norm. Twenty-nine patients (73%) had cognitive impairment. Adults performed better than children in the cognitive domain visuospatial functioning (p = 0.033, Bayes factor = 4.0), and children performed better in processing speed (p = 0.041, Bayes factor = 3.5). The authors did not find an association between infarction, white matter disease, or CVR and cognitive domains.

CONCLUSIONS

In this Western cohort, cognitive functioning in patients with moyamoya vasculopathy was below the population norm, and 73% had cognitive impairment in at least one domain. The cognitive profile differed between adults and children. The authors could not find an association with imaging findings.

Arterial spin labeling for moyamoya angiopathy: A preoperative and postoperative evaluation method

Objectives

Studies have shown that arterial spin labeling (ASL) effectively replaces traditional MRI perfusion imaging for detecting cerebral blood flow (CBF) in patients with Moyamoya angiopathy (MMA). However, there are few reports on the relationship between neovascularization and cerebral perfusion in patients with MMA. The aim of this study is to investigate the effects of neovascularization on cerebral perfusion with MMA after bypass surgery.

Methods

We selected patients with MMA in the Department of Neurosurgery between September 2019 and August 2021 and enrolled them based on the inclusion and exclusion criteria. ASL imaging was used to monitor the baseline CBF level before surgery and determine the changes in cerebral vessels at postoperative 1 week and 6 months, respectively. The Alberta stroke grade, modified Rankin Scale (mRS), and digital subtraction angiography images were used to evaluate the effect of postoperative CBF status and prognosis. Ninety hemispheres from 51 patients were included in this study. There were no significant differences in the baseline data of the enrolled patients. At 1 week and 6 months post-surgery, the CBF state in the operation area was significantly changed compared with that at baseline (P < 0.05). The preoperative Alberta score (t = 2.714, P = 0.013) and preoperative mRS score (t = 6.678, P < 0.001) correlated with postoperative neovascularization.

Conclusion

ASL is an effective method for detecting CBF and plays an important role in the long-term follow-up of patients with MMA. Combined cerebral revascularization significantly improves CBF in the operation area both in the short and long terms. Patients with lower preoperative Alberta scores and higher mRS scores were more likely to benefit from combined cerebral revascularization surgery. However, regardless of the type of patient, CBF reconstruction can effectively improve prognosis.

Clinical Outcome, Cognition, and Cerebrovascular Reactivity after Surgical Treatment for Moyamoya Vasculopathy: A Dutch Prospective, Single-Center Cohort Study

Background: It remains unclear whether revascularization of moyamoya vasculopathy (MMV) has a positive effect on cognitive function. In this prospective, single-center study, we investigated the effect of revascularization on cognitive function in patients with MMV. We report clinical and radiological outcome parameters and the associations between clinical determinants and change in neurocognitive functioning. Methods: We consecutively included all MMV patients at a Dutch tertiary referral hospital who underwent pre- and postoperative standardized neuropsychological evaluation, [15O]H2O-PET (including cerebrovascular reactivity (CVR)), MRI, cerebral angiography, and completed standardized questionnaires on clinical outcome and quality of life (QOL). To explore the association between patient characteristics, imaging findings, and change in the z-scores of the cognitive domains, we used multivariable linear- and Bayesian regression analysis. Results: We included 40 patients of whom 35 (27 females, 21 children) were treated surgically. One patient died after surgery, and two withdrew from the study. TIA- and headache frequency and modified Rankin scale (mRS) improved (resp. p = 0.001, 0.019, 0.039). Eleven patients (seven children) developed a new infarct during follow-up (31%), five of which were symptomatic. CVR-scores improved significantly (p < 0.0005). The language domain improved (p = 0.029); other domains remained stable. In adults, there was an improvement in QOL. We could not find an association between change in imaging and cognitive scores. Conclusion: In this cohort of Western MMV patients, TIA frequency, headache, CVR, and mRS improved significantly after revascularization. The language domain significantly improved, while others remained stable. We could not find an association between changes in CVR and cognitive scores.

Preoperative Collateral Perfusion Using Arterial Spin Labeling: A Predictor of Surgical Collaterals in Moyamoya Angiopathy

Objectives

Various degrees of surgical collateral circulation are often found in moyamoya angiopathy (MMA) patients after revascularization. Little is known about arterial spin labeling (ASL) that affects surgical collateral circulation. This study aimed to investigate the effect of ASL on surgical collaterals in patients with MMA after combined bypass surgery.

Methods

MMA patients with complete radiological and clinical information, who had undergone combined bypass, were enrolled in this study. Surgical collaterals were classified as good or poor based on the Matsushima standard. Cerebral perfusion on ASL was quantitatively analyzed as relative cerebral blood flow (rCBF). The qualitative collateral score was calculated using a four-grade scale. Univariable and multivariable logistic regressions were performed to identify the predictors for surgical collaterals after combined bypass.

Results

In total, 66 hemispheres of 61 patients (47 years old ± 8.66) were prospectively included (29 and 37 hemispheres with good and poor surgical collaterals, respectively). The presurgical collateral score was significantly lower in patients with good surgical collaterals (13.72 scores ± 7.83) than in those with poor surgical collaterals (19.16 scores ± 6.65, P = 0.005). The presurgical rCBF and modified Rankin scale (mRS) scores were not significantly different between the two groups (P_rCBF = 0.639, P_mRS = 0.590). The collateral score was significantly elevated (good: 13.72 scores ± 7.83 vs. 20.79 scores ± 6.65, P < 0.001; poor: 19.16 scores ± 6.65 vs. 22.84 scores ± 5.06, P < 0.001), and the mRS was reduced (good: 1.66 scores ± 1.14 vs. 0.52 scores ± 0.83, P < 0.001; poor: 1.49 scores ± 0.90 vs. 0.62 scores ± 0.76, P < 0.001) in patients after revascularization. Multivariable logistic regression showed that preoperative collateral scores [odds ratio (OR): 0.791; 95% confidence interval (CI): 0.695, 0.900; P < 0.001], age (OR: 0.181; 95% CI: 0.039, 0.854; P = 0.031), sex (OR: 0.154; 95% CI: 0.035, 0.676; P = 0.013), and hypertension (OR: 0.167; 95% CI: 0.038, 0.736; P = 0.018) were predictors of surgical collaterals after combined revascularization.

Conclusion

The preoperative collateral score based on ASL could be a predictor for surgical collaterals in patients with MMA after combined bypass surgery. Combined with age, sex, and hypertension, it may have a better predictive effect.

Cerebral Ischemic Complications After Surgical Revascularization for Moyamoya Disease: Risk Factors and Development of a Predictive Model Based on Preoperative Nutritional Blood Parameters

Objectives

Cerebral ischemic complications are common after revascularization in patients with moyamoya disease (MMD). Risk factors from specific laboratory variables have only been assessed by limited research. This study was to investigate the association between postoperative cerebral ischemia and nutritional blood parameters and examine predictive values of such risk factors in adults.

Methods

Preoperative demographics and nutritional blood parameters of patients with MMD who received revascularization at our institution from 2012 to 2021 were retrospectively reviewed. Univariate analysis and multivariable logistic regression were used to identify independent risk factors for the onset of postoperative cerebral ischemic complications. Predictive values were tested and a model incorporating these independent risk factors was created using the R program. Area under the receiver operating characteristic curve (AUC) was used for testing its discriminability.

Results

Postoperative cerebral ischemic complications occurred in 32 patients of 100 included procedures. Surgery on the left hemisphere, lower admission modified Rankin Scale (mRS) score, aberrant nutritional parameters including low white blood cell (WBC), and high total cholesterol (TC) were significantly associated with cerebral ischemic complications after revascularization. The intriguing role of WBC might be explained by altered immunomodulation. The AUC of this model with novel nutritional parameters yielded a value of 0.811, presenting better predictive accuracy. Additionally, the model was visualized in the form of a nomogram and translated into a user-friendly calculator to generate individual risk.

Conclusions

Surgical side, admission mRS score, WBC, and TC were independent risk factors for postoperative cerebral ischemic complications. The model composed of these four parameters was promising to be adopted in clinical practice.

Quantitative Optical Coherence Tomography Angiography in Patients with Moyamoya Vasculopathy: A Pilot Study

Moyamoya (MM) disease is a chronic cerebrovascular disease that can lead to progressive stenosis of the terminal portions of the internal carotid arteries and their proximal branches. We sought to investigate and quantify retinal vascular changes in patients with MM vasculopathy (MMV) using optical coherence tomography angiography (OCTA) compared to healthy controls. Our findings reveal retinal microvascular changes in patients with MMV and highlights the potential of OCTA imaging for the detection of subclinical retinal pathology.

Western Moyamoya Phenotype: A Scoping Review

Moyamoya, a rare angiographic finding, is characterized by chronic and progressive stenosis at the terminal end of the internal carotid artery, followed by collateralization of the cerebral vasculature at the base of the skull. Coined by Suzuki and Takaku in 1969, the term "moyamoya" means a "puff of smoke" in Japanese, a reference to the angiographic appearance of moyamoya collateralization. Moyamoya is most commonly found in East Asian countries, where much governmental and civilian effort has been expended to characterize this unique disease process. However, despite its rarity, the occurrence of moyamoya in Western countries is associated with significant divergence regarding incidence, gender, sex, age at diagnosis, clinical presentation, and outcomes. Here, we attempted to review the Western literature on moyamoya presentation using the PubMed database to characterize the Western phenotype of moyamoya. We were guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). We reviewed papers generated from a search with keywords "moyamoya case report," those reported from a Western institution, and those reported on a relevant association. Our scoping review demonstrated various clinical associations with moyamoya. Moreover, we summarized the demographic profile and clinical symptomatology, as well as reported disease associations to better elucidate the Western phenotype of moyamoya.

Trends in Literature on Cerebral Bypass Surgery: A Systematic Review

INTRODUCTION

Ever since the beginning of cerebral bypass surgery, the role of the bypass has been debated and indications have changed over the last 5 decades. This systematic literature research analysed all clinical studies on cerebral bypass that have been published from January 1959 to January 2020 for their year of publication, country of origin, citation index, role of and indication for bypass, bypass technique, revascularized territory, flow capacity, and title (for word cloud analysis per decade).

METHODS

A systematic literature research was conducted using PubMed, Web of Science, EMBASE, and SCOPUS databases. All studies that have been published until January 1, 2020, were included.

RESULTS

Of 6,013 identified studies, 2,585 were included in the analysis. Of these, n = 1,734 (67%) studies addressed flow-augmentation bypass and n = 701 (27%) addressed flow-preservation bypass. The most common indication reported for flow augmentation is moyamoya (n = 877, 51%), followed by atherosclerotic steno-occlusive disease (n = 753, 43%). For flow preservation, the most common indication is studies reporting on cerebral aneurysm surgery (n = 659, 94%). The increasing popularity of reporting on these bypass operations almost came to an end with the FDA approval of flow diverters for aneurysm treatment in 2011. Japan is the country with the most bypass studies (cumulatively published 933 articles), followed by the USA (630 articles) and China (232 articles).

DISCUSSION/CONCLUSION

Clinical studies on cerebral bypass surgery have become increasingly popular in the past decades. Since the introduction of moyamoya as a distinct pathologic entity, Asian countries in particular have a very active community regarding this disease, with an increasing number of articles published every year. Studies on bypass for chronic steno-occlusive disease peaked in the 1980s but have remained the main focus of bypass research, particularly in many European departments. The number of reports published on these bypass operations significantly decreased after the FDA approval of flow diverters for aneurysm treatment in 2011.

Patients with Moyamoya Vasculopathy Evaluated at a Single-Center in The Netherlands; Clinical Presentation and Outcome

Information on presentation and outcome of moyamoya vasculopathy (MMV) in European countries is limited. We investigated patient characteristics, treatment and outcome of patients with MMV. We retrieved patient characteristics and treatment information and determined functional outcome (modified Rankin Score (mRS); type of school/work) by structured telephone interviews. We performed uni- and multivariable logistic regression analysis to determine predictors of poor outcome. We included 64 patients with bilateral MMV. In children (31 patients), median age was 5 years (interquartile range (IQR) 2-11) and in adults (33 patients), it was 33 years (IQR 28-41). Predominant mode of presentation was ischemia (children 84%; adults 88%). Modified Rankin Scale (mRS) at presentation was ≤2 in 74%. Revascularization was performed in 42 patients (23 children). Median follow-up time was 46 months (IQR 26-90). During this period, 16 patients had recurrent stroke(s) and four patients died. In 73% of the patients (83% surgical group; 55% medically treated group), mRS was ≤2; 46% were able to return to regular school or work, of whom only 41% were on the same level. Univariable analysis revealed that surgical treatment was associated with lower odds of poor outcome ((mRS ≥ 3), OR 0.24; p = 0.017). This association was no longer statistically significant (OR 3.47; p = 0.067) in the multivariable model, including age and diagnosis (moyamoya disease or moyamoya syndrome). In this cohort of patients with MMV who presented in a single European center, a large proportion had good functional outcome. Nevertheless, less than half were able to attend regular school or were able to work at their previous level, indicating a large impact of the disease on their life.

Contralateral improvement of cerebrovascular reactivity and TIA frequency after unilateral revascularization surgery in moyamoya vasculopathy

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Contralateral cerebrovascular reactivity may improve after unilateral surgery in moyamoya.

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TIA frequency from the contralateral hemisphere can decrease after unilateral moyamoya surgery.

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These findings support staged rather than direct bilateral surgery in moyamoya.

Objective

Moyamoya vasculopathy is a rare, often bilateral disease characterized by progressive stenosis and occlusion of the distal internal carotid artery, leading to a progressive deterioration of cerebrovascular reactivity (CVR) and increased risk of transient ischemic attacks (TIAs), infarction and hemorrhage. Surgical revascularization is a widely accepted symptomatic treatment, often performed bilaterally in one or two stages. To possibly further optimize treatment strategy, we investigated the effect of unilateral revascularization surgery on the CVR of, and TIA frequency originating from, the contralateral hemisphere.

Methods

From our database of 143 moyamoya vasculopathy patients we selected those with bilateral disease, who underwent hemodynamic imaging ([15O]H2O positron emission tomography (PET)-CT with acetazolamide challenge) before and 14 months (median) after unilateral revascularization. We evaluated CVR in three regions per hemisphere, and averaged these per hemisphere for statistical comparison. Conservatively treated patients were showed as a comparison group. To examine TIA frequency, we selected patients who presented with TIAs that (also) originated from the contralateral – not to be operated – hemisphere. We scored changes in CVR and TIA frequency of the ipsilateral and contralateral hemisphere over time.

Results

Seven surgical and seven conservative patients were included for CVR comparison. Of the 20 scored contralateral regions in the surgical group, 15 showed improved CVR after unilateral revascularization, while 5 remained stable. The averaged scores improved significantly for both hemispheres. In conservatively treated patients, however, only 3 of the 20 scored regions improved in the least-affected (contralateral) hemispheres, and 9 deteriorated. From the 6 patients with contralateral TIAs at presentation, 4 had a decreased TIA frequency originating from the contralateral hemisphere after unilateral surgery, while 2 patients remained stable.

Conclusion

Both CVR and TIA frequency in the contralateral hemisphere can improve after unilateral revascularization surgery in bilateral MMV.

Individualized Perioperative Blood Pressure Management for Adult Moyamoya Disease: Experience from 186 Consecutive Procedures

BACKGROUND

In adult patients with moyamoya disease (MMD) underwent combined revascularization, cerebral infarction during the acute postoperative phase is common and can lead to neurological dysfunction after revascularization in MMD patients. The aim of this study was to share the experience of individualized perioperative blood pressure (BP) management for adult MMD patients in one single center.

METHODS

We retrospectively reviewed 144 adult patients with MMD who underwent 186 procedures of combined revascularization at our institution from March 2013 to July 2019. Clinical features and outcomes were analyzed, in particular regarding cerebral infarction and hyperperfusion syndrome (HPS). All of the patients received individualized management perioperatively, especially about the blood pressure management according to the characteristics of moyamoya disease.

RESULTS

Postoperative cerebral infarction and HPS within 14 days after revascularization were recorded. Cerebral infarction occurred in four (2.1%) procedures among four patients. No patients suffered from a malignant cerebral infarction and only one patient had permanent neurological deficits. The incidence of HPS was 10.8% and no one presented with intracranial hemorrhage. All of the symptoms were reversible without any brain parenchymal injury.

CONCLUSIONS

Our findings suggest that we can decrease the incidence and extent of cerebral infarction in adult MMD patients following combined revascularization by individualized perioperative BP management.

Severe cerebral edema induced by watershed shift after bypass in a patient with chronic steno-occlusive disease: a case report and short literature review

Background

Carotid occlusive disease is a type of progressive disease resulting in ischemic stroke. Extracranial-intracranial bypass surgery represents a valid therapeutic option when medical treatment does not make effects. The appearance of cerebral edema following bypass is common during acute stage. Additionally, there are many causes of mild cerebral edema, such as hemodynamic changes, venous congestion and others. However, severe edema involving large brain tissue, which presents as reversible aphasia and hemiplegia, remains to be elucidated.

Case presentation

A 55-year-old man was admitted to the neurosurgery department for repeated dizziness for over a year and sudden onset of syncope 1 month prior, and he was diagnosed with carotid occlusive disease. After surgical contraindications were excluded, dual bypass and encephalo-duro-myo-synangiosis were performed. Although blood pressure and fluid management were strictly under control promptly after surgery, massive cerebral edema involving the left anterior cerebral artery and middle cerebral artery territories occurred from the 6th day after surgery. Additionally, no discernible cerebral infarction or hemorrhage occurred. Moreover, the cerebral blood flow of the middle cerebral artery displayed an early decrease followed by delayed elevation on the left side. Without restricting the spreading of cerebral edema, life-threatening cerebral herniation could develop at any time. Mannitol and furosemide were administered for impending cerebral herniation. The amelioration of symptoms was noticed on the 16th day after surgery. The patient felt relief on the 21st day after surgery. Digital subtraction angiography performed on the 180th day after surgery demonstrated the patency of dual anastomosed vessels, and the patient recovered without any permanent neurological deficit.

Conclusion

Based on changes in cerebral blood flow and reversible symptoms, the “watershed shift” phenomenon could explain such a severe deficit. However, this deficit was not the same as the classical presentation of the “watershed shift”, which involves a moderate amount of brain tissue and presents significant increases in cerebral blood flow. In addition to the “watershed shift”, a swollen temporal muscle may also participate in the progression of focal edema.

A critical appraisal of bypass surgery in moyamoya disease

Moyamoya disease (MMD) is a complex cerebrovascular disorder about which little is known. Conventionally, revascularization surgery is recommended for patients, despite an absence of conclusive data from adequate clinical trials. Underscoring the uncertainty that exists in treating MMD patients, investigators continue to present data comparing revascularization with conservative or medical management, most of which originates from East Asia where MMD is most prevalent. The purpose of this manuscript is to review contemporary large case series, randomized trials, and recent meta-analyses that compare surgical and medical treatments in adult patients with MMD, and to critically analyze the modern literature in the context of current practice standards. Data from the available literature is limited, but revascularization seems superior to conservative therapy in adult patients presenting with hemorrhage, and in preventing future hemorrhages. Conversely, evidence that surgery is superior to medical therapy is not convincing in adult patients presenting with cerebral ischemia, or for the prevention of future ischemic events. In contrast to East Asian populations, MMD in Europe and in the Americas is predominantly an ischemic disease that presents in adulthood. Adequate multinational trials are warranted.

Impact of Endothelial Shear Stress on the Bilateral Progression of Unilateral Moyamoya Disease

Background and Purpose—

In unilateral moyamoya disease, altered endothelial shear stress on the intact-side terminal internal carotid artery might trigger the progression to bilateral disease. We analyzed the endothelial shear stress parameters of the normally appearing terminal internal carotid artery in unilateral moyamoya disease and its association with the progression to bilateral disease.

Methods—

This retrospective cohort study included patients diagnosed with unilateral moyamoya disease by cerebral angiography and followed-up with regular magnetic resonance imaging/magnetic resonance angiography evaluations for >1 year. Endothelial shear stress parameters acquired were mean and maximum signal intensity gradients (SIG) and SIG SD at the vessel boundary in time-of-flight sequences in initial brain magnetic resonance imaging/magnetic resonance angiography. Contralateral disease progression defined as the detection of newly developed vessel steno-occlusion with an magnetic resonance angiography steno-occlusive stage of ≥2, in the previously intact side of the brain on follow-up magnetic resonance imaging/magnetic resonance angiography evaluation.

Results—

Among 146 patients (66 males [45.2%] and 80 females [54.8%]; 76 pediatric [52.1%]), contralateral disease progression was detected in 43 patients (29.5%) after a mean follow-up of 4.3±2.4 years. Multivariate analysis showed that SIG SD was significantly associated with this progression (odds ratio, 13.001 [95% CI, 1.764−95.794], P =0.012). In receiver operating characteristic curve analysis, SIG SD predicted the contralateral progression with area under the curve values of 0.803 (95% CI, 0.726−0.880, P <0.001). The regression model was reproduced in the external cohort of 31 patients.

Conclusions—

Increased spatial variability of the endothelial shear stress around the normally appearing terminal internal carotid artery, as measured by SIG SD in time-of-flight sequences, may predict the contralateral progression of unilateral moyamoya disease.

Decreased frontal white-matter diffusion and improved cognitive flexibility after burr-hole surgery in moyamoya angiopathy

BACKGROUND

In Moyamoya Angioplasty (MMA), increased apparent diffusion coefficient (ADC) in frontal white matter (WM) with a normal appearance has been associated with frontal hypoperfusion and executive dysfunction. Multiple burr-hole surgery enables the revascularization of large frontal areas.

GOAL

To assess the effect of multiple burr-hole surgery on the ADC and cognitive functions in adults with MMA.

METHODS

ADC was measured in 26 brain hemispheres of 14 consecutive adults with MMA (9 women, mean age ± SD: 38.1 ± 10.7 years) prior to and 6 months after burr-hole surgery. ADC was obtained from regions of interest located in frontal and posterior (temporo-occipital) normal-appearing WM. Ten patients had neuropsychological assessment that focused on executive and attentional functions before and after surgery.

RESULTS

Anterior and posterior ADC values did not differ before surgery (815.8 ± 60.1 vs. 812.1 ± 35.3 mm²/s, p = 0.88). After surgery, frontal ADC was lower than prior to surgery (789.9 ± 64.5 vs. 815.8 ± 60.1 mm²/s; p <0.001) whereas no change occurred in posterior ADC (p = 0.31). Trail-making test part B median z-score increased from - 1.47 to - 0.21 (p = 0.018), suggesting improved cognitive flexibility.

CONCLUSION

In adults with MMA, indirect revascularization with burr-hole is followed by a decrease of ADC in normal-appearing frontal WM and may have improved some executive functions in the flexibility process. Change in ADC may reflect the improvement in cerebral perfusion after surgery. The measuring of ADC may be a promising tool in exploring potentially reversible microstructural WM damage related to hypoperfusion and cognitive change in MMA.

Neuropsychological profile associated with Moyamoya disease: A case report

BACKGROUND

Moyamoya disease (MMD) is a rare cardiovascular condition characterized by stenosis and gradual occlusion of the internal carotid arteries near the Circle of Willis. Current research on the disease has primarily been restricted to its medical implications, without adequate appreciation for its neurocognitive and/or neuropsychiatric implications.

OBJECTIVES

The current study presents the neurocognitive profile of a 31-year-old woman diagnosed with MMD, further complicated by cerebral vascular accidents (CVAs) and history of bilateral craniotomy aimed at providing maximal revascularization.

METHODS

Although speech and motor disturbances experienced by Ms. Doe around the time of her craniotomy and CVA were resolved at the time of current evaluation, she reported experiencing continued difficulties in processing speed, concentration, memory, word-retrieval, and planning. The patient underwent comprehensive neuropsychological evaluation assessing multiple cognitive domains.

RESULTS

Neurocognitive evaluation revealed the presence of a lateralized profile as well as impairments in simple auditory attention, processing speed, working memory, verbal learning, verbal fluency, and speeded fine-motor dexterity.

CONCLUSIONS

MMD significantly impacts cognition and daily functioning in affected individuals. This is often further exacerbated by additional CVAs requiring surgical intervention. While there is a clear growth of research on MMD, limited information is available on the neurocognitive and neuropsychiatric outcomes of the disease process. Neuropsychological data from the current case study is closely examined to provide a unique example of the lateralized neuropsychological profile and deficit pattern in a historically high functioning individual diagnosed with MMD following a stroke.

Outcomes in Patients with Moyamoya Syndrome and Sickle Cell Disease: A Systematic Review

BACKGROUND

Moyamoya syndrome, a progressive, idiopathic stenosis of the internal carotid arteries, results in increased risk for both ischemic and hemorrhagic strokes. Revascularization procedures have been shown in small studies to be both safe and efficacious for these patients; however, randomized controlled trials are lacking. The goal of this systematic review is to organize the literature evaluating surgical intervention versus conservative medical management.

METHODS

A systematic review was performed including studies with 3 or more participants with moyamoya syndrome in the setting of sickle cell disease and a measured outcome after either medical or surgical intervention. Relevant studies were identified using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria and a set of predetermined key words.

RESULTS

Sixty-one articles were identified with 6 articles ultimately included in this review (N = 122). Of the patients, 73 (59.8%) were revascularized surgically (all indirect procedures), whereas 49 (40.2%) remained on chronic transfusion therapy. Of the patients that underwent indirect revascularization surgery, a total of 1 perioperative (1.4%) and 4 postoperative strokes (5.5%) were reported over 44 months (1 stroke per 53.3 patient-years). In comparison, an average of 46.5% of patients who were receiving chronic transfusions had major events (stroke or transient ischemic attack) while undergoing therapy (1 stroke per 13.65 patient-years, P = 0.00215).

CONCLUSIONS

We present a large systematic review of the literature regarding outcomes of surgical and medical management for patients with moyamoya syndrome and sickle cell disease. The findings redemonstrate the efficacy and safety of surgical revascularization, and advocate for earlier discussion around surgical intervention.

Circular RNAs and neutrophils: Key factors in tackling asymptomatic moyamoya disease

Moyamoya disease (MMD) represents a rare steno-occlusive disorder affecting the terminal ends of the internal carotid artery and promoting the development of a poor, abnormal vascular network at the brain's base. Primarily affecting East Asian countries over Western populations, MMD can be further divided into symptomatic and asymptomatic subtypes. The current knowledge of the underlying mechanisms and potential management strategies for asymptomatic cases of MMD are largely lacking and thus warrant investigation to elucidate the pathology of this rare disorder. Here, we assess research examining the expression profile of circular RNAs (circRNAs) of neutrophil transcriptome in asymptomatic MMD patients. These findings conclude that 123 differentially expressed circRNAs significantly contributed to metabolism, angiogenesis, and immune response. The hypoxia-inducing factor-1α signaling pathway was also revealed to be crucial in angiogenesis. We also evaluate current therapeutic options demonstrating the potential for MMD patients, such as EC-IC bypass and ischemic pre- and post-conditioning. These approaches combined with recent findings on the circRNA expression profile suggest a crucial role of anti-inflammatory and angiogenic-related mechanisms underlying MMD. Investigating the role of circRNAs and neutrophils in the asymptomatic MMD subtype may provide insight into its elusive pathology and direct future approaches to combat the progression of this rare disease.

Tyrosine kinase inhibitor toxicity manifesting as comorbid Moyamoya syndrome and obstructive coronary artery disease: A case report and review of the literature

Tyrosine kinase inhibitors (TKIs) have assumed an increasingly vital role in treating various hematologic and oncologic malignancies. However, adverse effects with respect to vascular disease have been reported following administration of this class of medications. Here, we present a case report of TKI toxicity, manifesting as comorbid Moyamoya syndrome and obstructive coronary artery disease leading to a type 1 non-ST-elevation myocardial infarction. This patient eventually required percutaneous coronary intervention with drug-eluting stent placement in the right coronary artery. Given the expanding indications of TKI therapy, this case highlights a growing population subset which may require coronary and/or peripheral interventions to treat sequela from otherwise life-prolonging treatment.

Cerebrovascular Reactivity Measured with ASL Perfusion MRI, Ivy Sign, and Regional Tissue Vascularization in Moyamoya

BACKGROUND

Arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) may be used to determine brain regions at risk for ischemia in patients with moyamoya vasculopathy and to identify patients who may benefit from surgical revascularization. We aimed to investigate whether 1) the severity of moyamoya is related to the presence of leptomeningeal collaterals and cerebrovascular reactivity (CVR), 2) the presence of collaterals and ivy sign reflects disturbed CVR, and 3) arterial transit artefacts (ATAs) and ivy sign reflect the presence of collaterals.

METHODS

We determined severity of moyamoya on digital subtraction angiography (DSA) according to the modified Suzuki classification in 20 brain regions and scored regional tissue revascularization using a 4-point scale. Regional CVR and ATAs were assessed on ASL perfusion MRI, ivy sign on fluid attenuation inversion recovery MRI.

RESULTS

In 11 patients (median age 36 years; 91% female), we studied 203 regions. ATAs were associated with the presence of collaterals on DSA (P < 0.01). Of all regions with clearly visible collateral vessels on DSA, however, only 24% had ATAs. Ivy sign was not related to the presence or absence of collaterals nor to CVR. In 10% of regions with good vascularization on DSA, CVR was poor or showed steal.

CONCLUSIONS

ATAs were associated with the presence of collaterals on DSA. Although DSA vascularization scores correlated with CVR, 10% of regions with good vascularization on DSA had absent CVR or steal on ASL-MRI. DSA and ivy sign did not provide adequate information on the hemodynamic status of brain tissue in patients with moyamoya vasculopathy.

A Comprehensive Meta-Analysis for Bypass Surgery in Adult Moyamoya

OBJECTIVE

To evaluate the outcomes of bypass surgery for adult moyamoya and compare different surgical modalities by performing a comprehensive meta-analysis of relevant studies.

METHODS

A systematic literature search was performed and articles regarding different treatments for adult patients with moyamoya were included. Odds ratios (ORs) were calculated to evaluate stroke recurrence, mortality, perioperative complications, and angiographic revascularization among different surgical methods and conservative treatment (CT).

RESULTS

A total of 17 studies with 2224 adult patients with moyamoya were included in the meta-analysis. Compared with CT, surgical revascularization significantly decreased the future stroke events in the total population ([OR] 0.404; 95% confidence interval [CI] 0.279-0.585; P < 0.001) and in the hemorrhagic-onset patients as well (OR 0.259; 95% CI 0.138-0.486; P < 0.001). However, for those patients with moyamoya and ischemia, there was no significant difference for future stroke events between the bypass and CT groups (OR 0.470; 95% CI 0.140-1.579; P = 0.222). Bypass also showed no mortality reduction compared with CT (OR 0.372; 95% CI 0.120-1.154; P = 0.087). For different surgical techniques, no differences for future stroke events, mortality, and perioperative complications were found between direct bypass and indirect bypass, whereas the degree of angiographic revascularization was better in the direct bypass group than in the indirect group (OR 4.720; 95% CI 1.222-18.230; P = 0.024).

CONCLUSIONS

The bypass treatment was superior to conservative treatment in preventing recurrent stroke in adult patients with moyamoya, especially in those with a hemorrhagic onset. Direct bypass is associated with better revascularization results compared with indirect bypass.

Proximal internal carotid artery stenosis associates with diffuse wall thickening in petrous arterial segment of moyamoya disease patients: a three-dimensional magnetic resonance vessel wall imaging study

PURPOSE

To investigate the association between proximal internal carotid artery (ICA) luminal narrowing and diffuse wall thickening (DWT) in ipsilateral petrous ICA in moyamoya disease (MMD) patients.

METHODS

Forty-one MMD (mean age 42.8 ± 11.0 years, 19 males) and 36 atherosclerotic patients (mean age 61.5 ± 7.1 years, 31 males) and 41 healthy controls were recruited and underwent carotid MR vessel wall imaging. The luminal narrowing of proximal ICA was evaluated by the diameter ratio of ICA to common carotid artery (DR_ICA/CCA). The wall thickness of petrous ICA was measured on T1-VISTA images. The enhancement degree of petrous ICA was recorded and graded into four grades (none to marked) on the CE-T1-VISTA images. The correlation between wall thickness in petrous ICA and DR_ICA/CCA was analyzed_. RESULTS: In total, 81 arteries of MMD patients and 64 arteries of atherosclerotic patients were included for analysis. The DR_ICA/CCA was significantly correlated with the wall thickness in petrous ICA in MMD (r = - 0.434, P < 0.001) and atherosclerotic groups (r = - 0.604, P < 0.001). Logistic regression analysis revealed that odds ratio (OR) of DR_ICA/CCA was 4.433 (95% CI 1.980-9.925, P < 0.001) and 2.212 (95% CI 1.253-3.905, P = 0.006) in MMD and atherosclerotic groups in discriminating petrous ICA DWT after adjusting for confounding factors. An increasing trend was found in prevalence of DWT and wall thickness with enhancement grades in petrous ICA in MMD (P = 0.02 and P = 0.01) and atherosclerotic groups (P < 0.001 and P < 0.001), respectively.

CONCLUSIONS

The proximal ICA luminal narrowing is significantly associated with wall thickness and diffuse wall thickening in ipsilateral petrous ICA in patients with carotid steno-occlusive diseases regardless of MMD or atherosclerosis.

Moyamoya Disease in Pregnancy: A 20-Year Single-Center Experience and Literature Review

BACKGROUND

Pregnancy is a potential risk factor for stroke in women with Moyamoya disease. However, the rarity of the disease has limited clinical expertise to ensure a healthy pregnancy. The aim of the present study was to explore the possible risk factors for hemorrhagic and ischemic stroke in pregnant women with Moyamoya disease.

METHODS

A retrospective review of cases in our hospital during a 20-year period and a review of the reported data were conducted to investigate pregnancy-related cerebrovascular events in women with Moyamoya disease.

RESULTS

Thirty pregnancies in 20 women with Moyamoya disease were identified in the case review of our hospital. All were previously diagnosed cases, and no stroke had occurred during the study period. In the reported data review, pregnancy-related stroke in women with Moyamoya disease was identified in 54 (44 intracranial hemorrhage and 10 cerebral infarction). Intracranial hemorrhage occurred most commonly during the antepartum period (n = 39; 88.6%), with most events occurring at ≥24 weeks. Of the intracranial hemorrhage cases, 7 (15.9%) were complicated by hypertensive disorders of pregnancy, and 8 patients (18.2%) died of stroke. The onset of cerebral infarction was either in the antepartum (n = 4; 40.0%) or postpartum (n = 6; 60.0%) period. All postpartum cases occurred within 3-7 days after delivery.

CONCLUSION

Pregnancy-related stroke in patients with Moyamoya disease might be susceptible to gestational age. Intracranial hemorrhage is prone to occur during the antepartum period, especially at ≥24 weeks, and cerebral infarction tends to occur postpartum.

Cognitive Functions in Children and Adults with Moyamoya Vasculopathy: A Systematic Review and Meta-Analysis

Background and Purpose

Patients with moyamoya vasculopathy (MMV) may experience cognitive impairment, but its reported frequency, severity, and nature vary. In a systematic review and metaanalysis, we aimed to assess the presence, severity, and nature of cognitive impairments in children and adults with MMV.

Methods

We followed the MOOSE guidelines for meta-analysis and systematic reviews of observational studies. We searched Ovid Medline and Embase for studies published between January 1, 1969 and October 4, 2016. Independent reviewers extracted data for mean intelligence quotient (IQ) and standardized z-scores for cognitive tests, and determined percentages of children and adults with cognitive deficits, before and after conservative or surgical treatment. We explored associations between summary measures of study characteristics and cognitive impairments by linear regression analysis.

Results

We included 17 studies (11 studies reporting on 281 children, six on 153 adults). In children, the median percentage with impaired cognition was 30% (range, 13% to 67%); median IQ was 98 (range, 71 to 107). Median z-score was –0.39 for memory, and –0.43 for processing speed. In adults, the median percentage with impaired cognition was 31% (range, 0% to 69%); median IQ was 95 (range, 94 to 99). Median z-scores of cognitive domains were between –0.9 and –0.4, with multiple domains being affected. We could not identify determinants of cognitive impairment.

Conclusions

A large proportion of children and adults with MMV have cognitive impairment, with modest to large deficits across various cognitive domains. Further studies should investigate determinants of cognitive deficits and deterioration, and the influence of revascularization treatment on cognitive functioning.

Visualization and Classification of Deeply Seated Collateral Networks in Moyamoya Angiopathy with 7T MRI

BACKGROUND AND PURPOSE

Collateral networks in Moyamoya angiopathy have a complex angioarchitecture difficult to comprehend on conventional examinations. This study aimed to evaluate morphologic patterns and the delineation of deeply seated collateral networks using ultra-high-field MRA in comparison with conventional DSA.

MATERIALS AND METHODS

Fifteen white patients with Moyamoya angiopathy were investigated in this prospective trial. Sequences acquired at 7T were TOF-MRA with 0.22 × 0.22 × 0.41 mm³ resolution and MPRAGE with 0.7 × 0.7 × 0.7 mm³ resolution. Four raters evaluated the presence of deeply seated collateral networks and image quality in a consensus reading of DSA, TOF-MRA, and MPRAGE using a 5-point scale in axial source images and maximum intensity projections. Delineation of deeply seated collateral networks by different imaging modalities was compared by means of the McNemar test, whereas image quality was compared using the Wilcoxon signed-rank test.

RESULTS

The relevant deeply seated collateral networks were classified into 2 categories and 6 pathways. A total of 100 collateral networks were detected on DSA; 106, on TOF-MRA; and 73, on MPRAGE. Delineation of deeply seated collateral networks was comparable between TOF-MRA and DSA (P = .25); however, both were better than MPRAGE (P < .001).

CONCLUSIONS

This study demonstrates excellent delineation of 6 distinct deeply seated collateral network pathways in Moyamoya angiopathy in white adults using 7T TOF-MRA, comparable to DSA.

Association of increased Treg and Th17 with pathogenesis of moyamoya disease

Immuno-inflammation has been shown to play a pivotal role in the pathogenesis of moyamoya disease (MMD). However, how did circulating Treg/Th17 cells involve in MMD patients remains unclear. 26 MMD, 21 atherothrombotic stroke, and 32 healthy controls were enrolled in this study. MMD patients have a significantly higher percentage of circulating Treg and Th17 cells as well as their dominantly secreting cytokines than other groups (P < 0.0001), whereas no difference was found in the ratio of Treg/Th17 between patients in MMD and atherothrombotic stroke group or control subjects (P = 0.244). However, the increased Treg in MMD patients which were enriched with FrIII Treg cells had deficient suppressive functions (P = 0.0017) compared to healthy volunteers. There was a positive correlation between Treg or TGF-β and MMD Suzuki’s stage. And the level of circulating Treg was as an independent factor associated with MMD stage. Besides, TGF-β was also correlated with the increased expression of VEGF in MMD patients. Our findings indicated an important involvement of circulating Treg in the pathogenic development of MMD and TGF-β in Treg induced VEGF.

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.

Hemodynamic Changes after Unilateral Revascularization for Moyamoya Disease: Serial Assessment by Quantitative Magnetic Resonance Angiography

BACKGROUND: Ultrasonic flow meters and quantitative magnetic resonance angiography quantitatively assess flow during hemodynamic evaluation of cerebral ischemia. Although their reliability and reproducibility have been verified, their clinical impact in moyamoya disease has rarely been reported.

OBJECTIVE: To investigate flow measurement outcomes in moyamoya disease patients pre- and postoperatively through a retrospective observational study.

METHODS: We evaluated 41 patients undergoing their first revascularization surgery who were followed ≥6 mo. Hemodynamic parameters were recorded preoperatively, at 1 and 6 mo postoperatively, and at the last follow-up. Demographic factors, Suzuki stage, and stroke development were also analyzed.

RESULTS: Patients’ median age was 37 yr (interquartile range [IQR], 27-43), and 16 (39.0%) patients were men. During follow-up, 9 (22.0%) patients experienced postoperative stroke (4 major strokes). Hemodynamic status was improved in 34 (82.9%) patients at the 6-mo follow-up. Median intraoperative flow was 41 mL/min (IQR, 25-59). Bypass flow peaked at 6 mo (median, 67 mL/min; IQR, 35-99). At the 1- and 6-mo follow-ups, ipsilateral hemispheric flow was significantly increased. The median proportion of posterior circulation at 6 mo was 44.4%, significantly lower than the preoperative proportion (50.1%). Abundant intraoperative bypass flow was associated with hemodynamic improvement, while low contralateral hemispheric flow was related with immediate postoperative ischemic stroke.

CONCLUSION: Ipsilateral hemispheric flow was increased during 6-mo follow-up, and posterior circulation flow burden was diminished. Abundant intraoperative bypass flow was associated with postoperative hemodynamic improvement. Low preoperative contralateral hemispheric flow was related with immediate postoperative ischemic stroke.

Neuropathology of cerebrovascular diseases

The chapter describes the epidemiology of cerebrovascular diseases, anatomy of the cerebral blood vessels, pathophysiology of ischemia, hypoxia, hypoxemia, anemic hypoxia, histotoxic hypoxia, carbon monoxide damage, hyperoxid brain damage and decompression sickness, and selective cell and regional vulnerability; diseases of the blood vessels including atherosclerosis, hypertensive angiopathy, small vessel disease, inflammatory vascular diseases, cerebral amyloid angiopathies, CADASIL, CARASIL and other diseases that can lead to cerebrovascular occlusion; intracranial and intraspinal aneurysms and vascular malformations; hematologic disorders that can cause cerebral infarct or hemorrhage; brain ischemic damage; and spontaneous intracranial bleeding. Within ischemic brain damage, focal cerebral ischemia, hemorrhagic infarct, brain edema, penumbra, global cerebral ischemia, venous thrombosis, lacunas and lacunar state, status cribosus, granular atrophy of the cerebral cortex, hippocampal sclerosis, vascular leukoencephalopathy Binswanger type and multi-infarct encephalopathy are discussed in detail. Cognitive impairment of vascular origin deserves an individual section.

Histopathological features of middle cerebral artery and superficial temporal artery from patients with moyamoya disease and enlightenments on clinical treatment

The histopathological features of the middle cerebral artery (MCA) and superficial temporal artery (STA) from moyamoya disease (MMD) and their relationships with gender, age, angiography stage were explored. The causes and the clinical significance of vasculopathy of STA were also discussed. The clinical data and specimens of MCA and STA from 30 MMD patients were collected. Twelve samples of MCA and STA from non-MMD patients served as control group. Histopathological examination was then performed by measuring the thickness of intima and media, and statistical analysis was conducted. The MCA and STA specimens from MMD group had apparently thicker intima and thinner media than those from the control group. There was no significant pathological difference between the hemorrhage group and non-hemorrhage group, and between the males and females in MMD patients. Neither the age nor the digital subtraction angiography (DSA) stage was correlated with the thickness of intima in MCA and STA. MMD is a systemic vascular disease involving both intracranial and extracranial vessels. Preoperative external carotid arteriography, especially super-selective arteriography of the STA, benefits the selection of donor vessel.

Cerebrovascular disease

With 16.9 million people who suffered a first-ever stroke in 2010 worldwide, stroke is a very common vascular disease. Epidemiologic studies have played an essential role in assessing this burden and in detecting the risk factors for stroke. Primary prevention of these risk factors, primarily hypertension, smoking, diabetes, and atrial fibrillation, has reduced the incidence in high-income countries. However, stroke remains a major cause of death and disability, and therefore research should be continued. Subarachnoid hemorrhages are less prevalent than strokes but have an even higher risk of death. Similar to stroke, epidemiologic studies identified smoking and hypertension as its most important risk factors, together with excessive alcohol intake. Although rare, arterial dissections, CADASIL, arteriovenous malformations, venous sinus thrombosis, moyamoya disease, and vasculitis can lead to serious symptoms. The burden and risk factors of those rare diseases are more challenging to assess. Whenever possible, they should be recognized in a timely manner for their increased risk of stroke, but most often they are diagnosed only at the time of stroke. Some cerebrovascular abnormalities do not result in immediate symptoms. This subclinical cerebrovascular disease includes silent infarcts, white-matter lesions, and microbleeds, and is incidentally found by neuroimaging. These lesions are not innocent, as several epidemiologic studies have associated subclinical cerebrovascular disease with an increased risk of stroke, cognitive decline, dementia, and death.

Diagnosing moyamoya syndrome using ultrasound - a case report

Background

Moyamoya syndrome is a vasculopathy characterised by progressive occlusion of the cerebral arteries resulting in the development of abnormal collateral circulation. To diagnose this syndrome, imaging of the cerebral arteries is required including CT- or MR-angiography and conventional angiography. We present a case of moyamoya disease with typical findings detected in the sonography. The diagnosis was suspected after reviewing the initial ultrasound images of the cerebral arteries with evidence for obliterated intracranial arteries and the detection of an existing collateral circulation network.

Case presentation

A 62 years old male patient presented in the hospital’s emergency department with symptoms indicating a subacute cerebrovascular event. Immediate sonographic studies showed a right-sided pulsatile Doppler-signal in the common and internal carotid arteries, suggestive of distal stenoses. In addition, the transcranial examination indicated obliteration of both middle cerebral arteries. Numerous arterial vessels suggestive of leptomeningeal collateral arteries revealed a strong arterial leptomeningeal flow. At this stage of the diagnostic work-up, the collateral circulation network, characteristic of moyamoya disease, was indicated by sonography. Moyamoya syndrome was verified by conventional angiography. The aetiological work remained empty, so the diagnosis of moyamoya disease was established.

Conclusion

Our case report indicates that sonography can be a useful tool for detecting the vaculopathy in moyamoya syndrome. In case routine procedures, such as the CT- or MR-angiography, with evidence for obliterated intracerebral arteries, ultrasound studies might provide important information regarding an existing collateral network in the scope of a moyamoya syndrome.

Sonographic findings associated with stenosis progression and vascular complications in moyamoya disease

OBJECT The progression of arterial stenosis in patients with moyamoya disease (MMD) has variable courses and an unclear mechanism. The authors hypothesized that elevated wall shear stress (WSS) at the terminal internal carotid artery (ICA) and proximal middle cerebral artery (MCA) may facilitate MMD progression. They indirectly evaluated the relative magnitude of WSS (WSS value [WSSV]) with MR angiography (MRA) and transcranial Doppler to determine its predictive value for stenosis progression (SP) and the development of vascular complications. METHODS Thirty-one medically treated patients (58 hemispheres and 95 nonoccluded vessels) were analyzed with serial MRA (median follow-up 23 months). The parameters studied were SP, SP rates (SPRs) for individual ICAs/MCAs, and their mean values from the ipsilateral hemispheres as mean SP (MSP) and MSP rates (MSPRs). Significant progression was defined as decrements of ≥ 20% for SP and MSP and ≥ 10%/year for SPR and MSPR. The development of vascular complications in relevant hemispheres was also recorded. The WSSV (dyne/cm(2)) was defined as the shear rate multiplied by blood viscosity. RESULTS After adjusting the initial stenosis degree and MRA stage of MMD, an SP of ≥ 20% and an SPR of ≥ 10%/year were associated with the highest-quartile WSSVs for all individual vessels and for MCAs and ICAs separately. For each hemisphere, an MSP of ≥ 20% and an MSPR of ≥ 10%/year were associated with the highest-quartile mean WSSVs. Furthermore, significant SP was highly correlated with vascular complications, and the highest-quartile mean WSSV was independently associated with vascular complications in relevant hemispheres. CONCLUSIONS An elevated WSSV is an independent predictor for SP and vascular complications in nonoccluded MMD.