Differences in Clinical Features among Different Onset Patterns in Moyamoya Disease

Knockdown the moyamoya disease susceptibility gene, RNF213, upregulates the expression of basic fibroblast growth factor and matrix metalloproteinase-9 in bone marrow derived mesenchymal stem cells

Moyamoya disease (MMD) is a chronic, progressive cerebrovascular occlusive disease. Ring finger protein 213 (RNF213) is a susceptibility gene of MMD. Previous studies have shown that the expression levels of angiogenic factors increase in MMD patients, but the relationship between the susceptibility gene RNF213 and these angiogenic mediators is still unclear. The aim of the present study was to investigate the pathogenesis of MMD by examining the effect of RNF213 gene knockdown on the expression of matrix metalloproteinase-9 (MMP-9) and basic fibroblast growth factor (bFGF) in rat bone marrow-derived mesenchymal stem cells (rBMSCs). Firstly, 40 patients with MMD and 40 age-matched normal individuals (as the control group) were enrolled in the present study to detect the levels of MMP-9 and bFGF in serum by ELISA. Secondly, Sprague-Dawley male rat BMSCs were isolated and cultured using the whole bone marrow adhesion method, and subsequent phenotypic analysis was performed by flow cytometry. Alizarin red and oil red O staining methods were used to identify osteogenic and adipogenic differentiation, respectively. Finally, third generation rBMSCs were transfected with lentivirus recombinant plasmid to knockout expression of the RNF213 gene. After successful transfection was confirmed by reverse transcription-quantitative PCR and fluorescence imaging, the expression levels of bFGF and MMP-9 mRNA in rBMSCs and the levels of bFGF and MMP-9 protein in the supernatant of the culture medium were detected on the 7th and 14th days after transfection. There was no significant difference in the relative expression level of bFGF among the three groups on the 7th day. For the relative expression level of MMP-9, there were significant differences on the 7th day and 14th day. In addition, there was no statistically significant difference in the expression of bFGF in the supernatant of the RNF213 shRNA group culture medium, while there was a significant difference in the expression level of MMP-9. The knockdown of the RNF213 gene affects the expression of bFGF and MMP-9. However, further studies are needed to determine how they participate in the pathogenesis of MMD. The findings of the present study provide a theoretical basis for clarifying the pathogenesis and clinical treatment of MMD.

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.

High-resolution MRI vessel wall enhancement in moyamoya disease: risk factors and clinical outcomes

OBJECTIVES

Intracranial vessel wall enhancement (VWE) on high-resolution magnetic resonance imaging (HRMRI) is associated with the progression and poor prognosis of moyamoya disease (MMD). This study assessed potential risk factors for VWE in MMD.

METHODS

We evaluated MMD patients using HRMRI and traditional angiography examinations. The participants were divided into VWE and non-VWE groups based on HRMRI. Logistic regression was performed to compare the risk factors for VWE in MMD. The incidence of cerebrovascular events of the different subgroups according to risk factors was compared using Kaplan-Meier survival and Cox regression.

RESULTS

We included 283 MMD patients, 84 of whom had VWE on HRMRI. The VWE group had higher modified Rankin Scale scores at admission (p = 0.014) and a higher incidence of ischaemia and haemorrhage (p = 0.002) than did the non-VWE group. Risk factors for VWE included the ring finger protein 213 (RNF213) p.R4810K variant (odds ratio [OR] 2.01, 95% confidence interval [CI] 1.08-3.76, p = 0.028), hyperhomocysteinaemia (HHcy) (OR 5.08, 95% CI 2.34-11.05, p < 0.001), and smoking history (OR 3.49, 95% CI 1.08-11.31, p = 0.037). During the follow-up of 63.9 ± 13.2 months (median 65 months), 18 recurrent stroke events occurred. Cox regression showed that VWE and the RNF213 p.R4810K variant were risk factors for stroke.

CONCLUSION

The RNF213 p.R4810K variant is strongly associated with VWE and poor prognosis in MMD. HHcy and smoking are independent risk factors for VWE.

CLINICAL RELEVANCE STATEMENT

Vessel wall enhancement in moyamoya disease is closely associated with poor prognosis, especially related to the ring finger protein 213 p.R4810K variant, hyperhomocysteinaemia, and smoking, providing crucial risk assessment information for the clinic.

KEY POINTS

• The baseline presence of vessel wall enhancement is significantly associated with poor prognosis in moyamoya disease. • The ring finger protein 213 p.R4810K variant is strongly associated with vessel wall enhancement and poor prognosis in moyamoya disease. • Hyperhomocysteinaemia and smoking are independent risk factors for vessel wall enhancement in moyamoya disease.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

INTERPRETATION

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

Moyamoya Disease and Steno-Occlusive Disease in a Young Stroke Patient: A Case Report

Moyamoya disease is a rare cerebrovascular disorder characterized by progressive stenosis and occlusion of the intracranial arteries, resulting in the formation of collateral vessels. We present a case of a 24-year-old South Asian female with no prior medical history who presented with persistent headaches, right-hand numbness and pain, and global aphasia. Imaging revealed severe steno-occlusive disease involving the left internal carotid artery terminus, the proximal middle cerebral artery (MCA), and the anterior cerebral artery. The patient underwent a hemicraniectomy due to malignant MCA syndrome and was prescribed aspirin and fluoxetine. Further evaluation with a cerebral angiogram revealed severe steno-occlusive disease involving the left internal carotid artery terminus, the proximal middle cerebral artery, and the anterior cerebral artery. The patient had Moyamoya disease. This case emphasizes the necessity of including Moyamoya disease in the differential diagnosis, as it can result in serious neurological impairments.

Moyamoya Vasculopathy in Neurofibromatosis Type 1 Pediatric Patients: The Role of Rare Variants of RNF213

Neurofibromatosis type 1 (NF1) is a neurocutaneous disorder caused by mutations in NF1 gene, coding for neurofibromin 1. NF1 can be associated with Moyamoya disease (MMD), and this association, typical of paediatric patients, is referred to as Moyamoya syndrome (MMS). MMD is a cerebral arteriopathy characterized by the occlusion of intracranial arteries and collateral vessel formation, which increase the risk of ischemic and hemorrhagic events. RNF213 gene mutations have been associated with MMD, so we investigated whether rare variants of RNF213 could act as genetic modifiers of MMS phenotype in a pediatric cohort of 20 MMS children, 25 children affected by isolated MMD and 47 affected only by isolated NF1. By next-generation re-sequencing (NGS) of patients' DNA and gene burden tests, we found that RNF213 seems to play a role only for MMD occurrence, while it does not appear to be involved in the increased risk of Moyamoya for MMS patients. We postulated that the loss of neurofibromin 1 can be enough for the excessive proliferation of vascular smooth muscle cells, causing Moyamoya arteriopathy associated with NF1. Further studies will be crucial to support these findings and to elucidate the possible role of other genes, enhancing our knowledge about pathogenesis and treatment of MMS.