Adult Moyamoya Disease and Syndrome: Current Perspectives and Future Directions: A Scientific Statement From the American Heart Association/American Stroke Association

Transfer RNAs and transfer RNA-derived small RNAs in cerebrovascular diseases

This article explores the important functions of transfer RNA and - transfer RNA derived small RNAs (tsRNAs) in cellular processes and disease pathogenesis, with a particular emphasis on their involvement in cerebrovascular disorders. It discusses the biogenesis and structure of tsRNAs, including types such as tRNA halves and tRNA-derived fragments, and their functional significance in gene regulation, stress response, and cell signaling pathways. The importance of tsRNAs in neurodegenerative diseases, cancer, and cardiovascular diseases has already been highlighted, while their role in cerebrovascular diseases is in early phase of exploration. This paper presents the latest advancements in the field of tsRNAs in cerebrovascular conditions, such as ischemic stroke, intracerebral hemorrhage, and moyamoya disease. Furthermore, revealing the aptitude of tsRNAs as biomarkers for the prediction of cerebrovascular diseases and as targets for therapeutic intervention. It provides insights into the role of tsRNAs in these conditions and proposes directions for future research.

Clinical Characteristics and Multi-Model Imaging Analysis of Moyamoya Disease: An Observational Study

PURPOSE

Previous studies have lacked a comprehensive analysis of imaging modalities for diagnosing Moyamoya disease (MMD). This study aims to bridge this gap by utilizing multi-modal imaging to provide a more detailed understanding of the clinical and imaging characteristics of MMD.

METHODS

A retrospective analysis was conducted on seventy-eight adult MMD patients enrolled from March 2018 to March 2021. The study focused on clinical features, imaging findings, and treatment outcomes, with a particular emphasis on the comparative efficacy of different imaging modalities.

RESULTS

In this series, clinical manifestations varied depending on the type of MMD, with intracerebral hemorrhage (ICH) being the most common (69.2%), followed by cerebral infarction (25.6%). Imaging techniques provided critical diagnostic insights: magnetic resonance imaging (MRI) demonstrated superior sensitivity over computed tomography (CT) in detecting hemorrhages, whereas computed tomography angiography (CTA) and digital subtraction angiography (DSA) identified intricate vascular lesions, including moyamoya vessels and aneurysms. Notably, cerebral perfusion imaging (CTP) highlighted significant differences in cerebral blood flow and volume between infarction and hemorrhage cases. This comprehensive imaging approach guided varied therapeutic strategies, including bypass surgery in 57 patients and interventional embolization for aneurysms in 14 patients.

CONCLUSION

The authors' findings underscore the critical role of early diagnosis using DSA, whereas highlighting CTA and MRA as valuable noninvasive tools for screening and follow-up. The integration of multi-modal imaging provides a detailed vascular assessment crucial for individualized patient management, facilitating timely interventions and significantly improving clinical outcomes.

Cerebrovascular implications of takayasu arteritis: a review

PURPOSE

Takayasu arteritis (TA) is a rare, chronic, inflammatory large-vessel vasculitis that affects the aorta and its main branches, including the cerebrovascular system. This review analyzes current knowledge and patient outcomes concerning the cerebrovascular implications of TA.

METHODS

A literature search, with publications from 1994 to 2024, identified pertinent studies through PubMed. An illustrative case report details a 19-year-old female with Type 1 TA, illustrating the complex decision required in the absence of surgical or endovascular options.

RESULTS

Our results offer a demographic analysis of 1,698 TA patients, highlighting a female predominance of 89.99% and a mean symptom onset at 33 years. The clinical spectrum of cerebrovascular involvement presented varied symptoms, most notably dizziness, with significant incidences of ischemic events and bilateral stenosis primarily affecting the carotid and subclavian arteries. The most common type of TA was Type V, affecting 40% of patients studied. Endovascular treatment had a 95% initial success rate, with a 67% restenosis rate. Surgical treatment was successful in 84% of cases, but 21% had notable post-operative complications. Similar to the endovascular population, those treated with stand-alone conservative therapy saw a 93% initial remission rate with 52% having relapsed.

CONCLUSION

Assessing the disease activity of TA is crucial when planning vascular intervention due to its significant impact on treatment outcomes. Despite its greater initial invasiveness, surgical interventions showed lower restenosis rates compared to either endovascular interventions or standalone conservative management. We emphasize advancements in TA management and the pressing need for continued research into diagnostic and treatment protocols for improved patient outcomes.

Superficial Temporal Artery Size Changes After Encephaloduroarteriosynangiosis for the Treatment of Moyamoya Disease

BACKGROUND AND OBJECTIVE

Surgery is the mainstay of stroke prevention in patients with symptomatic moyamoya disease (MMD). We present the results of a single-center retrospective study of indirect revascularization surgery for adult MMD, emphasizing angiographic outcomes, including dilation of the superficial temporal artery and formation of new collaterals.

METHODS

A prospectively maintained database of procedures performed for MMD was reviewed. Adult patients treated with indirect revascularization and with long-term angiographic follow-up were included. Preoperative and postoperative angiographic images and baseline and procedural characteristics were analyzed. A Wilcoxon signed-rank test was used to test the hypothesis that the superficial temporal artery increases in diameter postoperatively.

RESULTS

We identified 40 hemispheres in 27 patients, of which 35 had a sufficient angiographic follow-up. Bilateral procedures were performed on 16 patients. Most patients were female (72.5%), with a median age of 43 years old. The most common clinical presentation was ischemic stroke in 59.3% of cases. All patients underwent an encephaloduroarteriosynangiosis for treatment. A follow-up angiogram was performed at a median of 13.8 months postoperatively, showing superficial temporal artery (STA)-derived collaterals in 71.4% and collateral ingrowth via the burr holes in 61.8% of cases. Disease progression was evident in 34.3% of hemispheres. The normalized STA diameter was significantly increased postoperatively (2.4 to 3 mm; P < 0.05). A univariate analysis revealed that transdural collaterals and hyperlipidemia may affect collateral ingrowth from the STA, and no other patient- or procedure-related factors, including replacement of the bone flap, impacted on this.

CONCLUSIONS

A significant increase in STA diameter on follow-up angiography after encephaloduroarteriosynangiosis was found; however, this was not directly associated with STA collateral development. Rates of postoperative transient ischemic attacks were low, and no patients had a new ischemic or hemorrhagic stroke at last follow-up. The presence of transdural collaterals and the absence of hyperlipidemia were associated with STA collateral development on follow-up angiography, but the causality of this finding is unclear.

The Impact of Revascularization Surgery on Headaches in Association with Cerebrovascular Reactivity in Patients with Moyamoya Angiopathy

BACKGROUND/OBJECTIVES

Headaches in Moyamoya angiopathy are common but poorly understood. We aimed to investigate if headaches in Moyamoya angiopathy improve after revascularization surgery and whether this is associated with improvement in cerebrovascular reactivity on MRI (CVR-MRI).

METHODS

We included consecutive adult patients with Moyamoya angiopathy who had chart data on headaches, CVR-MRI, and underwent extracranial-intracranial bypass surgery between January 2010 and September 2022 at a tertiary neurovascular referral center. Clinical and CVR-MR imaging data of all patients were collected through systematic chart review, complemented by standard-of-care headache questionnaires from patients who were operated between 2018 and 2022. We evaluated headache features and explored the association between headaches and CVR before and after revascularization surgery.

RESULTS

Fifty-nine patients were included (mean age 47 ± 14 years, 43 females (73%)); among them, 41/59 (69%) reported headaches pre-surgery. Headache improved in 28/41 (68%) patients after revascularization surgery with a reduction in pain severity (median VAS-score from 5/10 to 2.5/10; p = 0.002), analgesic use (from 84% to 40%; p = 0.007), and sick leave (from 60% to 16%; p < 0.001). Improvement in headaches was associated with improvement in CVR (OR 5.3; 95% CI: 1.2-23.5) and sick leave reduction (OR 1.4; 95% CI: 1.6-121.4).

CONCLUSIONS

Headaches in Moyamoya angiopathy are common and disabling. They may improve in most patients after revascularization surgery and seem to be associated with improvement in CVR, supporting the hypothesis of a potential vascular origin of the headaches.

Identification of lysosome-related hub genes as potential biomarkers and immune infiltrations of moyamoya disease by multiple bioinformatics methods and machine-learning strategies

Background

Moyamoya disease (MMD), characterized by chronic cerebrovascular pathology, poses a rare yet significant clinical challenge, associated with elevated rates of mortality and disability. Despite intensive research endeavors, the exact biomarkers driving its pathogenesis remain enigmatic.

Methods

The expression patterns of GSE189993 and GSE141022 were retrieved from the Gene Expression Omnibus (GEO) repository to procure differentially expressed genes (DEGs) between samples afflicted with MMD and those under control conditions. The Least Absolute Shrinkage and Selection Operator (LASSO), Support Vector Machine with Recursive Feature Elimination (SVM-RFE), and Random Forest (RF) algorithms were employed for identifying candidate diagnostic genes associated with MMD. Subsequently, these candidate genes underwent validation in an independent cohort (GSE157628). The CMAP database was ultimately employed to forecast drugs pertinent to MMD for clinical translation.

Results

A collective of 240 DEGs were discerned. Functional enrichment scrutiny unveiled the enrichment of the cholesterol metabolism pathway, salmonella infection pathway, and allograft rejection pathway within the MMD cohort. EPDR1, DENND3, and NCSTN emerged as discerned diagnostic biomarkers for MMD. The CMAP database was ultimately employed to scrutinize the ten most auspicious pharmaceutical compounds for managing MMD. Finally, after validation through in vitro experiments, EPDR1, DENND3, and NCSTN were identified as the key genes.

Conclusion

EPDR1, DENND3, and NCSTN have emerged as potential novel biomarkers for MMD. The involvement of T lymphocytes, neutrophilic granulocytes, dendritic cells, natural killer cells, and plasma cells could be pivotal in the pathogenesis and advancement of MMD.

Approach to adult Moyamoya disease presenting as bilateral anterior circulation infarcts: a case report

Moyamoya disease (MMD) is a rare progressive condition of unknown etiology that affects the blood vessels in the brain and is characterized by narrowing or stenosis of the distal parts of the internal carotid and major intracranial arteries, leading to the development of fragile collateral supplies. This makes it a significant causative factor for both ischemic strokes as well as intracerebral hemorrhages. As per the recommendations by the Research Committee on Moyamoya disease in 2021, the diagnostic criteria for MMD are essentially based on indicative radiological findings on cerebral angiography or MRI Brain and MRA, after excluding possible differentials. In this case report, we present the case of a 45-year-old Asian lady who presented with sudden-onset headaches and right-sided weakness. Her admission non-contrast CT brain scan was undiagnostic. MRI brain and MRA scans revealed bilateral anterior circulation watershed infarcts of variable age along with supra-clinoid stenosis. She was initially treated with steroids for vasculitis after discussions with a multidisciplinary team involving neurologists, stroke physicians and neuro-radiologists; however, further imaging revealed a diagnosis of MMD, and she was subsequently referred for revascularization surgery. Given the limited number of similarly documented cases, we hope this report will contribute to the knowledge base.

Post-infectious Moyamoya Syndrome: A Review of Existing Scientific Literature From 2000 to 2023

Moyamoya disease (MMD) is considered a primary disorder of an unknown etiology. In contrast, Moyamoya syndrome (MMS) refers to MMD associated with other underlying diseases, such as meningitis in childhood, neurofibromatosis type II, Down syndrome, cranial irradiation, and different types of anemias, particularly hemoglobinopathies. We aimed to provide a comprehensive clinicopathological overview of MMS. All case reports and case series published from 2000 to 2023 pertaining to MMD were included in the study. Case studies, original articles, editorials, letters to editors, and clinical images were excluded. The search was conducted using the Boolean operators ("AND" and "OR") on PubMed and Google Scholar. A total of 13 case reports and one case series study were included. The study suggests infection might be a trigger in susceptible individuals. The autoimmune antibody findings (anti-double stranded DNA IgG) suggest a potential autoimmune component in some cases. There were diverse presentations and outcomes of post-infectious MMS, with a striking predominance of pediatric cases (66.66%) and a possible female predominance. Both computerized tomography (CT) and magnetic resonance imaging (MRI) showed evidence of restricted blood flow. CT showed that stenosis, occlusion, and collateral formation were frequent vascular findings, but often unspecified in severity. Infarction, hypodensities, and hematoma were the most common parenchymal findings (22.22% each). The findings on MRI were stenosis (50%) and collateral formation (44.44%). Infarction was the most common finding (66.66%) in parenchyma. Hydrocephalus, encephalomalacia, and atrophy were less frequent. Lesions were most frequent in the internal carotid artery (66.66%), middle cerebral artery (66.66%), and anterior cerebral artery (50%). Lesions were less frequent in the posterior cerebral, vertebral, and basilar arteries. The frontal lobe (38.89%) and basal ganglia (33.33%) were commonly affected parenchymal regions. The most common risk factor was human immunodeficiency virus (HIV) infection (50%), followed by trisomy 21, cryptococcal, and other types of meningitides. Aspirin (50%) and antiretroviral therapy (38.89%) were the cornerstones of treatment for MMS. This review accentuates the noteworthy obstacles presented by post-infectious MMS, especially its catastrophic effect on children and its correlation with HIV/AIDS. According to our elaborate literature search using PubMed and Google Scholar, this is the first narrative review in the existing scientific literature summarizing the literature on post-infectious MMS.

Neurovascular Issues in Antiphospholipid Syndrome: Arterial Vasculopathy from Small to Large Vessels in a Neuroradiological Perspective

Antiphospholipid syndrome (APS) is an autoimmune prothrombotic condition characterized by venous thromboembolism, arterial thrombosis, and pregnancy morbidity. Among neurological manifestations, arterial thrombosis is only one of the possible associated clinical and neuroradiological features. The aim of this review is to address from a neurovascular point of view the multifaceted range of the arterial side of APS. A modern neurovascular approach was proposed, dividing the CNS involvement on the basis of the size of affected arteries, from large to small arteries, and corresponding clinical and neuroradiological issues. Both large-vessel and small-vessel involvement in APS were detailed, highlighting the limitations of the available literature in the attempt to derive some pathomechanisms. APS is a complex disease, and its neurological involvement appears multifaceted and not yet fully characterized, within and outside the diagnostic criteria. The involvement of intracranial large and small vessels appears poorly characterized, and the overlapping with the previously proposed inflammatory manifestations is consistent.

Identification of oxidative phosphorylation-related genes in moyamoya disease by combining bulk RNA-sequencing analysis and machine learning

Introduction: Moyamoya disease (MMD) is a chronic cerebrovascular disease that can lead to ischemia and hemorrhagic stroke. The relationship between oxidative phosphorylation (OXPHOS) and MMD pathogenesis remains unknown. Methods: The gene expression data of 60 participants were acquired from three Gene Expression Omnibus (GEO) datasets, including 36 and 24 in the MMD and control groups. Differentially expressed genes (DEGs) between MMD patients MMD and control groups were identified. Machine learning was used to select the key OXPHOS-related genes associated with MMD from the intersection of DEGs and OXPHOS-related gene sets. Gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), gene set enrichment analysis (GSEA), Immune infiltration and microenvironments analysis were used to analyze the function of key genes. Machine learning selected four key OXPHOS-related genes associated with MMD: CSK, NARS2, PTPN6 and SMAD2 (PTPN6 was upregulated and the other three were downregulated). Results: Functional enrichment analysis showed that these genes were mainly enriched in the Notch signaling pathway, GAP junction, and RNA degradation, which are related to several biological processes, including angiogenesis, proliferation of vascular smooth muscle and endothelial cells, and cytoskeleton regulation. Immune analysis revealed immune infiltration and microenvironment in these MMD samples and their relationships with four key OXPHOS-related genes. APC co-inhibition (p = 0.032), HLA (p = 0.001), MHC I (p = 0.013), T cellco- inhibition (p = 0.032) and Type I IFN responses (p < 0.001) were significantly higher in the MMD groups than those in the control groups. The CSK positively correlated with APC co-inhibition and T cell-co-inhibition. The NARS2 negatively correlated with Type I IFN response. The SMAD2 negatively correlated with APC co-inhibition and Type I IFN response. The PTPN6 positively correlated with HLA, MHC I and Type I IFN responses. Discussion: This study provides a comprehensive understanding of the role of OXPHOS in MMD and will contribute to the development of new treatment methods and exploration of MMD pathogenesis.

Vascular architecture characters and risk factors analysis of unstable moyamoya disease

Background

In some MMD patients, the digital subtraction angiography (DSA) examination found, occlusion in the ipsilateral internal carotid artery or middle cerebral artery, accompanied by the formation of numerous moyamoya vessels. Conversely, the contralateral internal carotid artery or middle cerebral artery shows signs of stenosis without the presence of moyamoya vessels. Notably, cerebral perfusion studies reveal a similar or even more severe reduction in perfusion on the occluded side compared to the stenotic side. Importantly, clinical symptoms in these patients are typically attributed to ischemia caused by the stenotic side. This condition is referred to as unstable moyamoya disease (uMMD).

Objective

This clinical research focuses on evaluating risk factors related to MMD and developing strategies to minimize postoperative complications. The study aims to analyze vascular characteristics and identify potential risk factors in patients with uMMD.

Methods

The authors reviewed consecutive cases with complete clinical and radiological documentation of patients who underwent surgery between January 2018 and June 2023. Univariate analysis and multivariate logistic regression analysis were employed to understand the risk factors and prognosis of postoperative complications in uMMD.

Results

Postoperative complications were retrospectively analyzed in 1481 patients (aged 14 to 65). Among them, 1,429 patients were assigned to the conventional treatment group, while 52 were in the unstable moyamoya disease group. The uMMD treatment group showed a significantly higher incidence of early postoperative complications such as RIND, cerebral infarction, and cerebral hemorrhage (p < 0.05). Univariate and multivariate logistic regression analyses were conducted on the postoperative complications of 52 uMMD patients. Initial symptoms of stenosis ≤50% (univariate: p = 0.008, multivariate: p = 0.015; OR [95% CI] =23.149 [1.853-289.217]) and choosing occluded side surgery (univariate: p = 0.043, multivariate: p = 0.018; OR [95% CI] =0.059 [0.006-0.617]) were identified as significant risk factors for postoperative neurological complications.

Conclusion

Compared to the conventional treatment group, uMMD has higher complication rates, with vascular stenosis degree and surgical side selection identified as significant risk factors. A comprehensive understanding of preoperative clinical symptoms and vascular characteristics in moyamoya disease patients, coupled with the formulation of rational surgical plans, contributes positively to decreasing postoperative mortality and disability rates in uMMD.

Characterization of PANoptosis-related genes and the immune landscape in moyamoya disease

Moyamoya disease (MMD) is a cerebrovascular narrowing and occlusive condition characterized by progressive stenosis of the terminal portion of the internal carotid artery and the formation of an abnormal network of dilated, fragile perforators at the base of the brain. However, the role of PANoptosis, an apoptotic mechanism associated with vascular disease, has not been elucidated in MMD. In our study, a total of 40 patients' genetic data were included, and a total of 815 MMD-related differential genes were screened, including 215 upregulated genes and 600 downregulated genes. Among them, DNAJA3, ESR1, H19, KRT18 and STK3 were five key genes. These five key genes were associated with a variety of immune cells and immune factors. Moreover, GSEA (gene set enrichment analysis) and GSVA (gene set variation analysis) showed that the different expression levels of the five key genes affected multiple signaling pathways associated with MMD. In addition, they were associated with the expression of MMD-related genes. Then, based on the five key genes, a transcription factor regulatory network was constructed. In addition, targeted therapeutic drugs against MMD-related genes were obtained by the Cmap drug prediction method: MST-312, bisacodyl, indirubin, and tropanyl-3,5-dimethylbenzoate. These results suggest that the PANoptosis-related genes may contribute to the pathogenesis of MMD through multiple mechanisms.

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.

Comparison between moyamoya disease and moyamoya syndrome in Israel

BACKGROUND AND AIMS

Moyamoya is a chronic brain vasculopathy involving the distal intracranial internal carotid artery (ICA) or proximal middle cerebral artery (MCA). Moyamoya patients can be divided into those with primary moyamoya disease (MMD) and those with moyamoya secondary to other known causes such as intracranial atherosclerosis (moymoya syndrome [MMS]). Our aim was to compare the characteristics of MMD patients to those of MMS patients in a sample of Israeli patients seen over the course of 20 years at a tertiary referral center.

METHODS

Included patients were diagnosed with either MMD or MMS based on typical imaging findings and the presence or absence of known concomitant vascular risk factors or associated disorders and vascular disease. Patients with MMS were compared to those with MMD. Demographics, symptoms, signs, and radiological data were compared between the groups. Treatment options and long-term rates of recurrent stroke and functional outcome were also studied.

RESULTS

Overall, 64 patients were included (25 MMD, 39 MMS). Patients with MMD were significantly younger (median IQR 20 (7-32) vs. 40 (19-52); p=0.035). Patients with MMS more often had vascular risk factors but there were no significant differences in clinical presentations or long-term disability rates between the groups and a similar proportion of patients underwent surgical interventions to restore hemispheric perfusion in both groups (48% vs. 44% MMS vs. MMD; p=0.7). Almost one in four patient had a recurrent stroke after the initial diagnosis in both groups. Most recurrences occurred in the pre-surgery period in the MMS group and in the post-surgery period in the MMD group.

CONCLUSIONS

There were no statistically significant differences in clinical or radiological presentations between the MMS and MMD patients. The course is not benign with recurrent stroke occurring in as many as 25%. More data is needed in order to identify those at high risk for stroke occurrence and recurrence.

Neuregulin 1 as a potential biomarker for disease progression in moyamoya disease: A case-control study in Chinese population

OBJECTIVE

Moyamoya disease (MMD) is a rare and progressive stenosis of cerebral arteries characterized by abnormally proliferative vasculopathy. Current studies have demonstrated that Neuregulin 1 (NRG1) plays a key role in angiogenesis-related disorders. Thus, the aim of our study is to investigate the serum NRG1 levels and their clinical correlations in MMD patients.

METHODS

In this study, thirty adult patients with MMD and age-gender matched healthy controls were enrolled from our hospital between July 2020 and April 2022. Peripheral blood samples were collected at baseline, and clinical data were obtained from the electronic medical record system. Serum NRG1 concentrations were measured by enzyme-linked immunosorbent assay. Sanger sequencing was applied to detect the RNF213 p.R4810K mutation.

RESULTS

The serum NRG1 levels were significantly higher in MMD patients compared to controls (14.48 ± 10.81 vs.7.54 ± 6.35mmol/L, p < 0.001). No statistical difference in baseline clinical characteristics was found between both groups. Correlation analyses showed that NRG1 levels were positively associated with Suzuki staging (r = 0.4137, p = 0.023) while not related to other clinical features (reduced cerebral blood flow, posterior cerebral artery involvement, bilateral or unilateral steno-occlusive changes). Furthermore, subgroup analysis revealed that MMD patients with the RNF213 p.R4810K mutation presented with significantly higher NRG1 levels than those without the mutation (9.60 ± 0.929 vs. 25.89 ± 4.338 mmol/L, p = 0.001).

CONCLUSIONS

Our study suggests that increased serum NRG1 levels may constitute a characteristic feature of MMD, indicating a potential positive correlation with disease progression and the presence of the RNF213 mutation. This positions NRG1 as a potentially crucial target for further studies aimed at comprehending the pathogenesis of MMD.

Moyamoya Disease in a Child With Fanconi Anemia: An Anomaly or a Complication

Fanconi anemia (FA) is an inherited bone marrow failure syndrome associated with congenital anomalies and a predisposition to cancer. We report the case of a 9-year-old boy with FA who developed an abrupt onset of hemiplegia and dysarthria. The diagnosis of moyamoya disease (MMD) was suggested by magnetic resonance angiography (MRA) which demonstrated severe stenosis in the right internal carotid artery along with collateral vessel formation in the right basal ganglia. It is questioned whether the moyamoya pattern in this case is part of congenital malformations associated with FA or is the result of recurrent bleedings around the carotid siphon.

Switching of brain networks across different cerebral perfusion states: insights from EEG dynamic microstate analyses

The alteration of neural interactions across different cerebral perfusion states remains unclear. This study aimed to fulfill this gap by examining the longitudinal brain dynamic information interactions before and after cerebral reperfusion. Electroencephalogram in eyes-closed state at baseline and postoperative 7-d and 3-month follow-ups (moyamoya disease: 20, health controls: 23) were recorded. Dynamic network analyses were focused on the features and networks of electroencephalogram microstates across different microstates and perfusion states. Considering the microstate features, the parameters were disturbed of microstate B, C, and D but preserved of microstate A. The transition probabilities of microstates A-B and B-D were increased to play a complementary role across different perfusion states. Moreover, the microstate variability was decreased, but was significantly improved after cerebral reperfusion. Regarding microstate networks, the functional connectivity strengths were declined, mainly within frontal, parietal, and occipital lobes and between parietal and occipital lobes in different perfusion states, but were ameliorated after cerebral reperfusion. This study elucidates how dynamic interaction patterns of brain neurons change after cerebral reperfusion, which allows for the observation of brain network transitions across various perfusion states in a live clinical setting through direct intervention.