Moyamoya Periventricular Choroidal Collateral Registry-A Multicenter Cohort Study of Moyamoya Disease with Choroidal Anastomosis: Study Protocol.

Recent cohort studies on hemorrhagic and asymptomatic moyamoya disease have revealed that choroidal anastomosis, a type of fragile periventricular collateral pathway (periventricular anastomosis) typical of the disease, is an independent predictor of hemorrhagic stroke. However, treatment strategies for less-symptomatic nonhemorrhagic patients with choroidal anastomosis remain unclear. The Moyamoya Periventricular Choroidal Collateral (P-ChoC) Registry is an ongoing multicentered observational study that will test the hypothesis that extracranial-intracranial bypass prevents de novo hemorrhagic stroke in less symptomatic, nonhemorrhagic patients with choroidal anastomosis and may thus contribute to improving the prognosis of moyamoya disease. In this study, we report the study protocol of the moyamoya P-ChoC Registry and review the literature on choroidal anastomosis as a fragile collateral pathway.

Alterations in the Glymphatic System and Association with Brain Structure and Cognitive Function in Moyamoya Disease.

The glymphatic system is crucial for clearing metabolic waste from the brain, maintaining neural health and cognitive function. This study explores the glymphatic system's role in Moyamoya disease (MMD), characterized by progressive cerebral artery stenosis and brain structural lesions. We assessed 33 MMD patients and 21 healthy controls using diffusion tensor imaging along the perivascular space (DTI-ALPS) and global cortical gray matter-cerebrospinal fluid (CSF) coupling indices (gBOLD-CSF), which are indirect measurements of the glymphatic system. Cerebral perfusion in patients was evaluated via computed tomography perfusion imaging. We also measured the peak width of skeletonized mean diffusivity (PSMD), white matter hyperintensity (WMH) burden, and cognitive function. MMD patients exhibited lower ALPS and gBOLD-CSF coupling indices compared to controls (P < 0.01), indicating disrupted glymphatic function. Significant cognitive impairment was also observed in MMD patients (P < 0.01). ALPS indices varied with cerebral perfusion stages, being higher in earlier ischemic stages (P < 0.05). Analysis of brain structure showed increased CSF volume, PSMD index, and higher WMH burden in MMD patients (P < 0.01). The ALPS index positively correlated with white matter volume and cognitive scores, and negatively correlated with CSF volume, PSMD, and WMH burden (P < 0.05). Mediation analysis revealed the number of periventricular WMH significantly mediated the relationship between glymphatic dysfunction and cognitive impairment. In summary, MMD patients exhibit significant glymphatic system impairments, associated with brain structural changes and cognitive deficits.

Proteomics and digital subtraction angiography approaches reveal CDH18 as a potential target for therapy of moyamoya disease.

Moyamoya disease, characterized by basal cerebral artery obstruction, was studied for differential protein expression to elucidate its pathogenesis. Proteomic analysis of cerebrospinal fluid from 10 patients, categorized by postoperative angiography into good and poor prognosis groups, revealed 46 differentially expressed proteins. Notably, cadherin 18 (CDH18) was the most significantly upregulated in the good prognosis group. In addition, the expression of cadherin 18 (CDH18) and phenotypic transformation-related proteins were measured by qRT-PCR and western blot. The effects of CDH18 in vascular smooth muscle cells were detected by CCK-8, EdU, transwell and wound healing assays. The overexpression of CDH18 in vascular smooth muscle cells (VSMCs) was found to inhibit proliferation, migration, and phenotypic transformation. These findings suggest CDH18 as a potential therapeutic target in moyamoya disease.

Intersecting Pathologies: A Case Report on the Co-presentation of Quasi-Moyamoya Disease and Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal Plasma Cell Disorder, and Skin Changes (POEMS) Syndrome.

Moyamoya disease (MMD) is a rare chronic vasculopathy characterized by progressive stenosis of the internal carotid arteries and the formation of fragile collateral vessels in the brain. Polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes (POEMS) syndrome is a rare paraneoplastic syndrome with a complex presentation that includes polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes. Here, we report a unique case of a 54-year-old male with MMD presenting with recurrent speech loss and mumbling, later diagnosed with POEMS syndrome. Initial imaging revealed Moyamoya vasculopathy, confirmed by computed tomographic angiography (CTA) and magnetic resonance imaging (MRI). Further examination revealed polyneuropathy, organomegaly, and elevated vascular endothelial growth factor (VEGF), meeting the diagnostic criteria for POEMS syndrome. The patient was treated with a cyclophosphamide-bortezomib-dexamethasone regimen, followed by the addition of daratumumab, resulting in clinical improvement. This case highlights the importance of thorough diagnostics and a multidisciplinary treatment approach for patients with complex comorbidities, emphasizing the need for early detection and targeted therapy in managing dual pathologies of MMD and POEMS syndrome.

Pregnancy Risk Assessment, Management, and Delivery Plan for Pregnant Women with Moyamoya Disease Using a Multidisciplinary Collaborative Approach: A Case Series.

Purpose: This case report aimed to summarize the risk factors, clinical characteristics, imaging changes, and maternal and fetal prognosis associated with Moyamoya disease in pregnant women and to explore effective management strategies and a comprehensive delivery plan. Case Presentation: The clinical data of four pregnant women who were diagnosed with Moyamoya disease and admitted to our hospital between January 2010 and January 2019 were retrospectively analyzed. Their diagnosis, treatment, delivery, and postpartum management during the pregnancy were analyzed. Among the four pregnant women, three were primipara and one was multipara. The age ranged from 27 to 41 years old. The gestational week of termination of pregnancy ranged between 8 and 39 weeks. During pregnancy, one case died in utero; one case was complicated with postpartum hemorrhage; one case was complicated with chronic hypertension, multiple cerebral artery stenosis and occlusion, bilateral middle cerebral artery occlusion, bilateral internal carotid artery occlusion, and Hashimoto's thyroiditis. Under epidural anesthesia, two cases underwent a lower segment cesarean section; one case underwent artificial abortion; and one case underwent induced labor during late pregnancy. Two newborns survived. Conclusion: Moyamoya disease is a rare and serious complication of pregnancy. Pregnancy and childbirth may exacerbate the progression of this disease or induce cerebrovascular accidents, with a high mortality and disability rate, which seriously threatens the safety of mother and infant lives; however, with the close collaboration of a multidisciplinary team, it is possible to maximize a good pregnancy outcome.

Case Report: A rare presentation of rapidly progressive moyamoya disease refractory to unilateral surgical revascularization.

Moyamoya disease (MMD) is a chronic, occlusive cerebrovasculopathy typified by progressive steno-occlusive disease of the intracranial internal carotid arteries (ICAs) and their proximal branches. Moyamoya syndrome (MMS) categorizes patients with characteristic MMD plus associated conditions. As such, the most usual presentations are those that occur with cerebral ischemia, specifically transient ischemic attack, acute ischemic stroke, and seizures. Hemorrhagic stroke, headaches, and migraines can also occur secondary to the compensatory growth of fragile collateral vessels propagated by chronic cerebral ischemia. While the pathophysiology of MMD is unknown, there remain numerous clinical associations including radiation therapy to the brain, inherited genetic syndromes, hematologic disorders, and autoimmune conditions. We describe the case of a 31-year-old woman who presented with recurrent ischemic cerebral infarcts secondary to rapidly progressive, bilateral MMD despite undergoing early unilateral surgical revascularization with direct arterial bypass. She had numerous metabolic conditions and rapidly decompensated, ultimately passing away despite intensive and aggressive interventions. The present case highlights that progression of moyamoya disease to bilateral involvement can occur very rapidly, within a mere 6 weeks, a phenomenon which has not been documented in the literature to our knowledge.

Prediction of contralateral progression in patients with bilateral nonhemorrhagic moyamoya disease following unilateral revascularization surgery.

OBJECTIVE: This study was designed to identify predictive factors associated with substantial contralateral progression in adult patients with bilateral nonhemorrhagic moyamoya disease (MMD) who undergo revascularization surgery (RS) on one hemisphere. METHODS: The authors retrospectively analyzed 174 contralateral hemispheres of patients with bilateral nonhemorrhagic MMD (non-hMMD) who underwent RS on one side. The primary endpoint was defined as substantial contralateral progression requiring additional RS 6 months after the initial RS. The annual risk and predictive factors for contralateral progression were also analyzed. RESULTS: Of 174 patients included in the study, 57 (32.8%) experienced contralateral progression over a mean follow-up of 45.3 ± 31.6 months (range 12-196 months). The annual risk for contralateral progression after initial unilateral RS was 7.7% per person-year. Multivariable analysis revealed that age (HR 0.967, 95% CI 0.944-0.992; p = 0.009) and a BMI ≥ 25 (HR 1.946, 95% CI 1.126-3.362; p = 0.017) were significant predictors of contralateral progression. Specifically, the annual risk of contralateral progression was 12.1% in the higher BMI (≥ 25) group and 4.0% in the lower BMI (< 25) group per person-year. CONCLUSIONS: The study revealed a 7.7% per person-year rate of contralateral progression in patients with bilateral non-hMMD following unilateral RS. Younger age and a BMI ≥ 25 were identified as significant risk factors. For these patients, careful weight management and the use of antilipid agents may be crucial strategies for reducing the risk of contralateral progression after unilateral RS.

Exploring the impact of pre-anastomosis cerebral microcirculation on cerebral hyperperfusion syndrome in superficial temporal artery-middle cerebral artery bypass surgery of moyamoya disease.

Significance: Cerebral hyperperfusion syndrome (CHS), characterized by neurologic deficits due to postoperative high cerebral perfusion, is a serious complication of superficial temporal artery-middle cerebral artery (STA-MCA) surgery for moyamoya disease (MMD). Aim: We aim to clarify the importance of assessing pre-anastomosis cerebral microcirculation levels by linking the onset of CHS to pre- and post-anastomosis hemodynamics. Approach: Intraoperative laser speckle contrast imaging (LSCI) measured changes in regional cerebral blood flow (rCBF) and regional blood flow structuring (rBFS) within the cerebral cortical microcirculation of 48 adults with MMD. Results: Following anastomosis, all MMD patients exhibited a significant increase in rCBF ( 279.60 % ± 120.00 % , p < 0.001 ). Changes in rCBF and rBFS showed a negative correlation with their respective baseline levels (rCBF, p < 0.001 ; rBFS, p = 0.005 ). Baseline rCBF differed significantly between CHS and non-CHS groups ( p = 0.0049 ). The areas under the receiver operating characteristic (ROC) curve for baseline rCBF was 0.753. Hemorrhagic MMD patients showed higher baseline rCBF than ischemic patients ( p = 0.036 ), with a marked correlation between pre- and post-anastomosis rCBF in hemorrhagic cases ( p = 0.003 ), whereas ischemic MMD patients did not. Conclusion: Patients with low levels of pre-anastomosis baseline CBF induce a dramatic increase in post-anastomosis and show a high risk of postoperative CHS.

Contrast enhancement patterns associated with acute stroke in moyamoya disease using MR vessel wall imaging.

BACKGROUND AND PURPOSE: High-resolution magnetic resonance imaging (HR-MRI) can provide valuable insights into the histopathological characteristics of moyamoya disease (MMD). However, the patterns of vessel wall contrast enhancement have not been well established. We aimed to identify the contrast enhancement patterns of the vessel walls associated with acute cerebral infarction using HR-MRI in MMD. METHODS: In this retrospective study, we conducted genetic tests for Ring Finger Protein 213 (RNF 213) and performed HR-MRI on patients suspected of having MMD. We analyzed wall enhancement patterns including concentric, eccentric, or mixed enhancement types, and the occurrence of acute cerebral infarction in patients who simultaneously tested positive for RNF 213 and exhibited definite features of MMD on HR-MRI. RESULTS: Among 306 patients who underwent RNF 213 tests for the evaluation of MMD, 56 showed positive RNF 213, and HR-MRI was performed on 32 of them. Among the patients with acute cerebral infarction, the incidence rate was significantly higher in the group with concentric wall enhancement compared to patients without acute cerebral infarction (73.3% vs. 17.0%, p < .002). Furthermore, the incidence was notably elevated, even in patients with pure concentric wall enhancement (40.0% vs. 5.9%, p = .033). The area under the curve (AUC) for the group with any concentric wall enhancement showed a significant result of .78 (95% confidence interval [CI]: .61-.95, p = .007), whereas the predictive ability for pure concentric wall enhancement did not reach significance (AUC = .67, 95% CI: .48-.86, p = .100). CONCLUSIONS: Concentric wall enhancement was a significant predictor of acute cerebral infarction in patients with MMD.

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.

Illness uncertainty, resilience, and perceived social support among patients with moyamoya disease: a cross-sectional study.

Objective: The present study aims to investigate the levels of illness uncertainty in patients with moyamoya disease and to determine the association of socio-demographic characteristics, perceived social support and resilience with illness uncertainty in patients with moyamoya disease. Method: A cross-sectional survey using convenience sampling was conducted in two hospitals in China from August to December 2023. A socio-demographic characteristics questionnaire, the Chinese versions of Mishel's Unsurety in Disease Scale (MUIS), the Chinese version of Connor-Davidson Resilience Scale (CD-RISC), and the Chinese version of Multidimensional Scale of Perceived Social Support (MSPSS) were used to perform this research. The collected data were analyzed using SPSS 24.0 statistical software. The t-test, one-way analysis of variance (ANOVA), pearson correlation analysis and hierarchical regression analysis were used to identify associated factors. Result: A total of 263 patients with moyamoya disease were recruited in this survey. The score of illness uncertainty was at a moderate level of (100.03 ± 18.59). The present study identified a negative correlation between illness uncertainty with resilience perceived social support. Hierarchical regression analysis showed that gender, occupation, education level, resilience and perceived social support were the related factors of illness uncertainty. Conclusion: Patients with moyamoya disease experienced moderate disease uncertainty on average, which was related to gender, occupation, education level, resilience and perceived social support. Future research is needed to better explore the complex relationships between illness uncertainty, resilience, and perceived social support with different types of moyamoya disease using longitudinal research.

Transarterial Embolization With N-Butyl-2-Cyanoacrylate for Rapidly Enlarging Distal Anterior Choroidal Artery Aneurysm Associated With Moyamoya Disease: A Case Report.

Peripheral aneurysms associated with moyamoya disease, particularly those originating from the anterior choroidal artery, often have a poor prognosis and are typically managed with endovascular treatments. Comprehensive imaging diagnostics and anatomical expertise are critical in minimizing ischemic complications during treatment. We present a case of a 55-year-old woman with a rapidly enlarging distal anterior choroidal artery aneurysm identified during an intracerebral hemorrhage associated with moyamoya disease. The patient underwent super-selective embolization using N-butyl-2-cyanoacrylate (NBCA) during the chronic phase, resulting in a favorable outcome. Detailed intraoperative imaging was essential in guiding the treatment and mitigating risks.

Ultrasonographic Predictors for Post-operative Ischemic Events After Indirect Revascularization Surgeries in Patients with Moyamoya Disease.

OBJECTIVE: Recurrent stroke after revascularization surgeries predicts poor outcome in patients with moyamoya disease (MMD). Early identification of patients with stroke risk paves the way for rescue intervention. This study aimed to investigate the role of ultrasound in identifying patients at risk of post-operative ischemic events (PIEs). METHODS: This prospective study enrolled patients with symptomatic MMD who underwent indirect revascularization surgeries. Ultrasound examinations were performed preoperatively and at 3 mo post-operatively to evaluate the hemodynamic changes in extracranial and intracranial arteries on the operated side. PIE was defined as ischemic stroke or transient ischemic attack in the operated hemisphere within 1 y. The areas under receiver operating characteristic curves were compared between models for prediction of PIE. RESULTS: A total of 56 operated hemispheres from 36 patients (mean age, 23.0 ± 18.5 y) were enrolled in this study, and 27% developed PIE. In multivariate logistic regression models, PIE was associated with lower end-diastolic velocity and flow volume (FV) of the ipsilateral external carotid artery (ECA), and lower FV of ipsilateral superficial temporal artery and occipital artery at 3 mo post-operatively (all p < 0.05). Moreover, the post-operative FV of the ipsilateral ECA was the only one factor that significantly increased the areas under receiver operating characteristic curves from 0.727 to 0.932 when adding to a clinical-angiographic model for prediction of PIE (p = 0.017). This parameter was significantly lower in hemispheres with PIE, both in adult and pediatric patients. CONCLUSION: After indirect revascularization, surgeries in patients with symptomatic MMD, FV of ipsilateral ECA at 3 mo helps clinicians to identify patients at risk of PIE.

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.

Insights into the regulatory role of epigenetics in moyamoya disease: Current advances and future prospectives.

Moyamoya disease (MMD) is a progressive steno-occlusive cerebrovascular disorder that predominantly affecting East Asian populations. The intricate interplay of distinct and overlapping mechanisms, including genetic associations such as the RNF213-p.R4810K variant, contributes to the steno-occlusive lesions and moyamoya vessels. However, genetic mutations alone do not fully elucidate the occurrence of MMD, suggesting a potential role for epigenetic factors. Accruing evidence has unveiled the regulatory role of epigenetic markers, including DNA methylation, histone modifications, and non-coding RNAs (ncRNAs), in regulating pivotal cellular and molecular processes implicated in the pathogenesis of MMD by modulating endothelial cells and smooth muscle cells. The profile of these epigenetic markers in cerebral vasculatures and circulation has been determined to identify potential diagnostic biomarkers and therapeutic targets. Furthermore, in vitro studies have demonstrated the multifaceted effects of modulating specific epigenetic markers on MMD pathogenesis. These findings hold great potential for the discovery of novel therapeutic targets, translational studies, and clinical applications. In this review, we comprehensively summarize the current understanding of epigenetic mechanisms, including DNA methylation, histone modifications, and ncRNAs, in the context of MMD. Furthermore, we discuss the potential challenges and opportunities that lie ahead in this rapidly evolving field.

RNF213 Mutation Associated with the Progression from Middle Cerebral Artery Steno-Occlusive Disease to Moyamoya Disease.

Middle cerebral artery steno-occlusive disease (MCAD) has been recognized as a different clinical entity from moyamoya disease (MMD). Although MCAD can progress to MMD, the extent to which patients actually progress and the risk factors for this progression have not been fully elucidated. We retrospectively reviewed patients with MCAD who underwent RNF213 genotyping. Demographic features, RNF213 p.R4810K mutation, medical history, and longitudinal changes in angiography were analyzed. Sixty patients with 81 affected hemispheres were enrolled. During the follow-up period, 17 patients developed MMD, and the RNF213 p.R4810K mutation was the only factor significantly associated with progression to MMD (odds ratio, 16.1; 95% CI, 2.13-731; P = 0.001). The log-rank test demonstrated that patients with the mutation had a higher risk of progression to MMD (P = 0.007), stenosis progression (P = 0.010), and symptomatic cerebral infarction or hemorrhage (P = 0.026). In Cox regression analysis the p.R4810K mutation remained a significant factor after adjusting for age group (childhood or adult onset) at diagnosis (hazard ratio, 8.42; 95% CI, 1.10-64.4). Hemisphere-based analysis also showed that the mutation was associated with a higher risk of progression to the MMD hemisphere (P = 0.002), stenosis progression (P = 0.005), and cerebral infarction or hemorrhage (P = 0.012). The RNF213 p.R4810K mutation was identified as a risk factor for progression from MCAD to MMD. Genotyping for this mutation may contribute to risk stratification in MCAD.

Novel analysis of functional relationship linking moyamoya disease to moyamoya syndrome.

Objective: The aim of this study was to elucidate the genetic pathways associated with Moyamoya disease (MMD) and Moyamoya syndrome (MMS), compare the functional activities, and validate relevant related genes in an independent dataset. Methods: We conducted a comprehensive search for genetic studies on MMD and MMS across multiple databases and identified related genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments analyses were performed for these genes. Commonly shared genes were selected for further validation in the independent dataset, GSE189993. The Sangerbox platform was used to perform statistical analysis and visualize the results. P＜0.05 indicated a statistically significant result. Results: We included 52 MMD and 51 MMS-related publications and identified 126 and 51 relevant genes, respectively. GO analysis for MMD showed significant enrichment in cytokine activity, cell membrane receptors, enzyme binding, and immune activity. A broader range of terms was enriched for MMS. KEGG pathway analysis for MMD highlighted immune and cellular activities and pathways related to MMS prominently featured inflammation and metabolic disorders. Notably, nine overlapping genes were identified and validated. The expressions of RNF213, PTPN11, and MTHFR demonstrated significant differences in GSE189993. A combined receiver operating characteristic curve showed high diagnostic accuracy (AUC = 0.918). Conclusions: The findings indicate a close relationship of MMD with immune activity and MMS with inflammation, metabolic processes and other environmental factors in a given genetic background. Differentiating between MMD and MMS can enhance the understanding of their pathophysiology and inform the strategies for their diagnoses and treatment.

Assessing superficial temporal artery-middle cerebral artery anastomosis patency using FLOW 800 hemodynamics.

OBJECTIVE: The objective of this study was to investigate the use of indocyanine green videoangiography with FLOW 800 hemodynamic parameters intraoperatively during superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery to predict patency prior to anastomosis performance. METHODS: A retrospective and exploratory data analysis was conducted using FLOW 800 software prior to anastomosis to assess four regions of interest (ROIs; proximal and distal recipients and adjacent and remote gyri) for four hemodynamic parameters (speed, delay, rise time, and time to peak). Medical records were used to classify patients into flow and no-flow groups based on immediate or perioperative anastomosis patency. Hemodynamic parameters were compared using univariate and multivariate analyses. Principal component analysis was used to identify high risk of no flow (HRnf) and low risk of no flow (LRnf) groups, correlated with prospective angiographic follow-ups. Machine learning models were fitted to predict patency using FLOW 800 features, and the a posteriori effect of complication risk of those features was computed. RESULTS: A total of 39 cases underwent STA-MCA bypass surgery with complete FLOW 800 data collection. Thirty-five cases demonstrated flow after anastomosis revascularization and were compared with 4 cases with no flow after revascularization. Proximal and distal recipient speeds were significantly different between the no-flow and flow groups (proximal: 238.3 ± 120.8 and 138.5 ± 93.6, respectively [p < 0.001]; distal: 241.0 ± 117.0 and 142.1 ± 103.8, respectively [p < 0.05]). Based on principal component analysis, the HRnf group (n = 10) was characterized by high-flow speed (> 75th percentile) in all ROIs, whereas the LRnf group (n = 10) had contrasting patterns. In prospective long-term follow-up, 6 of 9 cases in the HRnf group, including the original no-flow cases, had no or low flow, whereas 8 of 8 cases in the LRnf group maintained robust flow. Machine learning models predicted patency failure with a mean F1 score of 0.930 and consistently relied on proximal recipient speed as the most important feature. Computation of posterior likelihood showed a 95.29% chance of patients having long-term patency given a lower proximal speed. CONCLUSIONS: These results suggest that a high proximal speed measured in the recipient vessel prior to anastomosis can elevate the risk of perioperative no flow and long-term reduction of flow. With an increased dataset size, continued FLOW 800-based ROI metric analysis could be used to guide intraoperative anastomosis site selection prior to anastomosis and predict patency outcome.

Magnetic Resonance Angiography Alone Is Insufficient for Diagnosis and Surgical Planning in Children With Moyamoya.

BACKGROUND: The gold standard for evaluation of the severity of moyamoya vasculopathy is the Suzuki grade determined with cerebral catheter angiography (CA). With greater use of magnetic resonance angiography (MRA) it is important to understand if MRA is truly comparable to CA. METHODS: Children with moyamoya were evaluated using the Suzuki score for CA and the modified MRA six-stage Suzuki score to describe the angiographic findings in moyamoya from initial narrowing of the distal internal carotid artery to the "puff of smoke" appearance of the lenticulostriate collaterals and finally to the disappearance of this network of collaterals. Using Cohen kappa we compared Suzuki grade based on CA with MRA in the same patients. RESULTS: A total of 27 children with moyamoya were reviewed. We calculated a weighted Cohen kappa of 0.49 (P < 0.0001), which is a moderate correlation. CONCLUSIONS: We suggest caution in the reliance on MRA for the diagnosis and evaluation of severity of moyamoya in children.

Clinical Features and Treatment Outcomes in Patients in Their Twenties with Ischemic Moyamoya Disease.

INTRODUCTION: Revascularization surgery is recommended for all pediatric patients with moyamoya disease (MMD) with ischemic symptoms because the brains of such patients are still developing. By contrast, no clear guidelines for selective revascularization surgery in adult patients (30 years or more) with ischemic presentation have been established. Regarding the age of initial onset of ischemic MMD, patients in their 20s are at the bottom of the distribution and this age group may share features with both adult and pediatric patients. The present prospective study aimed to clarify the clinical features and treatment outcomes of patients in their 20s (younger patients) with ischemic MMD compared with patients aged 30-60 years (older patients). METHODS: While patients with misery perfusion in the symptomatic cerebral hemisphere on 15O-positron emission tomography underwent combined surgery including direct and indirect revascularizations in the first study period and indirect revascularization alone in the second study period, patients without misery perfusion in that hemisphere received pharmacotherapy alone through the two study periods. Cerebral angiography via arterial catheterization and neuropsychological testing were performed before and after surgery. RESULTS: During 12 years, 12 younger patients were included and comprised 6% of all adult patients (194 patients). The incidence of misery perfusion in the affected hemisphere was significantly higher in younger (12/12 [100%]) than in older patients (57/182 [31%]) (p < 0.0001). No difference in the incidence of cerebral hyperperfusion syndrome and postoperatively declined cognition was seen between younger (2/5 [40%] and 2/5 [40%], respectively) and older (11/36 [31%] and 15/36 [42%], respectively) cerebral hemispheres undergoing combined revascularization surgery. No difference in the incidence of postoperatively formed collateral flows feeding more than one-third of the middle cerebral artery cortical territory on angiograms and postoperatively improved cognition was seen between younger (9/10 [90%] and 6/10 [60%], respectively) and older (18/22 [83%] and 14/22 [64%], respectively) cerebral hemispheres undergoing indirect revascularization surgery alone. CONCLUSION: Patients in their 20s with ischemic MMD always exhibit misery perfusion in the affected hemisphere, unlike older patients, and sometimes develop cerebral hyperperfusion syndrome after combined revascularization surgery, leading to cognitive decline, similar to older patients. Moreover, indirect revascularization surgery alone forms sufficient collateral circulation and restores cognitive function in patients in their 20s, similar to older patients.