moyamoya_disease

Moyamoya disease

Moyamoya disease is a chronic, occlusive cerebrovascular disease, characterized by bilateral steno-occlusive changes at the terminal portion of the internal carotid artery and an abnormal vascular network at the base of the brain.

These diagnostic criteria of the moyamoya disease, stated by the Research Committee on Spontaneous Occlusion of the Circle of Willis (moyamoya disease) in Japan, are well established and generally accepted as the definition of this rare entity. On the contrary to the diagnosis of definitive moyamoya disease, there is some confusion in the terminology and understanding of quasi-moyamoya disease; moyamoya disease in association with various disease entities, such as atherosclerosis, autoimmune diseases, Down syndrome, etc. Although the clinical management is not affected by these semantic distinctions, terminological confusion may interfere with the international collaboration of the clinical investigation of these rare conditions 1).

The perforating arteries in the basal ganglia and thalamus markedly dilate and function as an important collateral circulation, called as “moyamoya” vessels. The posterior cerebral artery are also involved in a certain subgroup of patients. Therefore, cerebral hemodynamics is often impaired especially in the frontal lobe, leading to transient ischemic attack (TIa) and cerebral infarction. Furthermore, the dilated, fragile moyamoya vessels often rupture and cause intracranial hemorrhage 2) 3).

Moyamoya Disease Epidemiology.

Moyamoya disease classification.

Unknown etiology.

A study indicated a higher overall autoimmune disease prevalence in unilateral than in bilateral MMD. Unilateral MMD may be more associated with autoimmune disease than bilateral MMD. Different pathogenetic mechanisms may underlie moyamoya vessel formation in unilateral and bilateral MMD 4).

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 5).

In the pathogenesis of MMD, the important role of genetic factors is being elucidated, and RNF213 has recently been identified as a susceptibility gene for MMD.

The aim of a retrospective study was to investigate the RNF213 genotype in patients with MMD and to determine their genotype-phenotype associations.

The study involved 165 Korean MMD patients from 155 unrelated families who were diagnosed with MMD at a single center from 1995 to 2013. Their demographic, radiological, and clinical findings were evaluated. Direct sequencing of the major RNF213 single nucleotide polymorphisms was performed. The association of the common RNF213 variant with MMD risk was evaluated using historical controls for comparison. Correlations between RNF213 genotype and phenotype were statistically analyzed.

The c.14429G>A (p.R4810K) variant was identified in 125 (75.8%) of 165 MMD patients. Most patients (112) were heterozygous, and 13 patients had 2 copies of the c.14429G>A variant. A novel heterozygous variant, c.12086A>G (p.Q4029R), was found in 1 additional patient. The minor allele frequency of the c.14429G>A variant was significantly higher in the MMD group (138 [41.8%] of 330 patients) than in the control group (8 [1.36%] of 588 subjects; p < 0.001). The c.14429G>A (p.R4810K) variant significantly increased the risk of MMD in Korean patients, with an OR of 52.11 (p < 0.001) compared with controls. Moreover, c.14429G>A (p.R4810K) genotypes occurred more frequently in patients with a family history of MMD. The homozygous variant was highly associated with early-onset MMD (age at onset < 5 years), cerebral infarction at diagnosis, and cognitive impairment in long-term outcome.

The findings indicate that the c.14429G>A (p.R4810K) allele of RNF213 is strongly associated with Korean patients with MMD. The homozygous c.14429G>A (p.R4810K) variant is particularly related to early-onset MMD, severe symptomatic manifestations at diagnosis, and poor prognosis. This genotypic variant may be a useful biomarker for early-onset MMD or unstable MMD with cerebral infarction, which requires early diagnosis and revascularization treatment 6).

see Moyamoya disease clinical features.

.

MoyaMoya Disease Diagnosis.

Quantification of the severity of vasculopathy and its impact on parenchymal hemodynamics is a necessary prerequisite for informing management decisions and evaluating intervention response in patients with moyamoya.

Computational fluid dynamics (CFD) analysis on eight patients (5 female, 3 male) with MMD treated by EDAS (encephalo-duro-arterio-synangiosis) between 2011 and 2012. All the eight patients presented with haemorrhage, with subsequent 4-12 month follow-up done using Magnetic Resonance Angiography (MRA) to capture auto-remodelling. Karunanithi et al. calculated percentage change in flow rate and pressure drop indicator (ΡDI) across the Left and Right ICA. Pressure drop indicator (PDI) is defined as the difference of pressure reduction within the carotid arteries, measured at post-op and follow up, using patient specific inflow rates. The measured percentage flow change and pressure reduction showed an increase at follow up for improved patients (characterised by angiography according to the method of Matsushima), who did not develop any complications after surgery. The inverse was observed in patients who were clinically classified as no change and retrogressed (according to the method of Matsushima) cases post-operation. This elucidates the findings of a new parameter that may well play a critical role as an assistive clinical decision making tool in MMD 7).

see Moyamoya disease treatment.

see Moyamoya disease outcome.

see Cerebral Infarction.

see Moyamoya disease case series.

Moyamoya disease case reports.


1)
Fujimura M, Tominaga T. Diagnosis of moyamoya disease: international standard and regional differences. Neurol Med Chir (Tokyo). 2015 Mar 15;55(3):189-93. doi: 10.2176/nmc.ra.2014-0307. Epub 2015 Feb 20. PubMed PMID: 25739428.
2)
Suzuki J, Takaku a: Cerebrovascular “moyamoya” disease. disease showing abnormal net-like vessels in base of brain. Arch Neurol 20: 288–299, 1969
3)
Kuroda S, Houkin K: Moyamoya disease: current concepts and future perspectives. Lancet Neurol 7: 1056–1066, 2008
4)
Chen JB, Liu Y, Zhou LX, Sun H, He M, You C. Increased prevalence of autoimmune disease in patients with unilateral compared with bilateral moyamoya disease. J Neurosurg. 2015 Sep 25:1-6. [Epub ahead of print] PubMed PMID: 26406790.
5)
Sun SJ, Zhang JJ, Li ZW, Xiong ZW, Wu XL, Wang S, Shu K, Chen JC. Histopathological features of middle cerebral artery and superficial temporal artery from patients with moyamoya disease and enlightenments on clinical treatment. J Huazhong Univ Sci Technolog Med Sci. 2016 Dec;36(6):871-875. PubMed PMID: 27924520.
6)
Kim EH, Yum MS, Ra YS, Park JB, Ahn JS, Kim GH, Goo HW, Ko TS, Yoo HW. Importance of RNF213 polymorphism on clinical features and long-term outcome in moyamoya disease. J Neurosurg. 2015 Oct 2:1-7. [Epub ahead of print] PubMed PMID: 26430847.
7)
Karunanithi K, Han C, Lee CJ, Shi W, Duan L, Qian Y. Identification of a hemodynamic parameter for assessing treatment outcome of EDAS in Moyamoya disease. J Biomech. 2015 Jan 21;48(2):304-9. doi: 10.1016/j.jbiomech.2014.11.029. Epub 2014 Nov 29. PubMed PMID: 25498370.
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  • Last modified: 2021/03/30 09:03
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