The publication of this monograph on moyamoya disease is well timed to provide inspiring guidance for future directions. The first monograph on moyamoya disease was published in 1986 by Professor Jiro Suzuki of Tohoku University, Japan.
Future Perspectives
Contributors
Ki Kwon MD, PhD
Department of Nuclear Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea. Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University of Medicine, Seoul, Republic of Korea.
Introduction
Moyamoya disease is a unique cerebrovascular disease with steno-occlusive changes at the terminal part of the internal carotid artery and fine vascular network, the so-called "moyamoya". Moyamoya disease shows racial differences in incidence and occurs mainly in East Asia with a worldwide distribution.
Definition and Diagnostic Criteria
MRA: stenosis or occlusion in the terminal part of the internal carotid artery without that in the proximal part of the anterior and/or middle cerebral artery. Note the stenosis at the terminal part of the internal carotid artery and the disappearance of the main trunks of the anterior and middle cerebral arteries on both sides.
Diagnosis
History
The title was "Hypoplasia of the bilateral internal carotid arteries" and they published this case in the Japanese journal Brain Nerve in 1957 [14]. In the same year, Kudo published a case report entitled "a case of hypoplasia of the circle of Willis" in the same journal [15].
Why “Moyamoya” (Fig. 5 )
Before the name 'moyamoya' disease appeared, several names were proposed for this pathological condition; cerebral juxta-basal telangiectasia, hemangiomatous malformation of the bilateral internal carotid arteries at the base of the brain, cerebral arterial rete and Nishimoto's disease (or Nishimoto-Takeuchi-Kudo)[19], etc. Due to the nuance of vague, mysterious, and unresolved in Japanese, the word 'moyamoya' also fits the unknown etiology of the disease.
Evolution of Research and Lessons from Moyamoya Disease
In the future, when the etiology of this disease is fully explained, the name "moyamoya" will become somewhat inappropriate. In addition, demands to prevent ischemic stroke have led to improvements in surgical procedures such as direct bypass techniques and indirect vascularization.
Introduction: Pathology of Moyamoya Disease
Histological Findings in Moyamoya Disease
Leptomeningeal Vessels
Vessels with Encephalo-myo-synangiosis
Perforators
Hemorrhage from Perforators
Furthermore, progressive stenoses of the moyamoya vessels, both in severity and distribution, may cause further stress on the remaining vessels, leading to eventual wall disruption. Small interrupted arteries organized within old hemorrhagic foci indicate that rupture of moyamoya vessels can also occur repeatedly.
Molecular Analysis with Intracranial Vessels
The increased blood supply would cause hemodynamic stress on these moyamoya vessels as a collateral pathway. In the last few decades, many studies have been carried out on genes or proteins (mostly growth factors or angiogenic factors) that were highly expressed in vessel walls, dura mater or cerebrospinal fluid [16–24].
Microbleeds in Moyamoya Disease
Although MBs are commonly located in both the basal ganglia and subcortical regions in patients with small vascular disease, MBs are primarily located in the periventricular white matter in patients with MMD. Development and dilation of the arteries located in the periventricular white matter, such as choroidal arteries and branches of posterior communicating arteries, have been reported as risk factors for hemorrhage in MMD [33, 34].
Epidemiology
According to their speculation, the difference in presentation between Asian and ethno-European patients is related to the later onset of vaso-occlusive vasculopathy in the ethno-European group [38]. Further research on MMD among ethno-Europeans could elucidate the underlying mechanism of racial differences associated with MMD.
Comparison with Moyamoya Syndrome
Irradiation
Contrast-enhanced MR imaging has revealed arterial wall thickening and enhancement in patients with radiation-induced large-vessel vasculopathy. These findings are similar to those frequently observed in patients with aortitis and atherosclerosis syndrome [46].
Down Syndrome
However, the arteries of patients with idiopathic MMD did not show marked strengthening of the arterial wall.
Postinfection
Endothelial Progenitor Cells in MMD
Genetic Analysis
Summary and Conclusion
Takagi Y, Kikuta K, Sadamasa N et al. 2006): Caspase-3-dependent apoptosis in middle cerebral arteries in patients with moyamoya disease. Aoyagi M, Fukai N, Yamamoto M et al. 1997): Development of intimal thickening in superficial temporal arteries in patients with moyamoya disease.
Clinical Features of Unilateral Moyamoya Disease
Also, until now, the natural history of unilateral moyamoya disease has been unclear, and whether it is an early form of moyamoya disease remains controversial. Here, although there have been only a small number of reports on this topic, we will review the clinical features and progression of disease in unilateral moyamoya disease.
Progression of Unaffected Hemisphere
Because bleeding in Moyamoya disease is believed to be caused by rupture of friable transmedullary collateral vessels or related aneurysms, the angiographic comparison between unilateral and typical Moyamoya disease may be important for comparing the incidence between the two diseases. Based on this limited reference, we cannot conclude whether the incidence of bleeding is higher with unilateral moyamoya.
Management Plans
Matsushima T, Take S, Fujii K et al (1988) A case of moyamoya disease with progressive involvement from unilateral to bilateral. Yoshida S, Matsumoto S, Ban S et al (1992) Moyamoya disease progressing from unilateral to bilateral involvement - a case report.
Prevalence and Incidence (Especially in Japan)
In the early 1970s, several studies first reported the epidemiological characteristics of moyamoya disease in Japan. A study on Moyamoya disease was first conducted in the Republic of Korea in 1988, and several reports on the epidemiology of this disease in the Republic of Korea have been published [ 6 , 7 ].
Gender Differences
The widespread use of non-invasive MRI may increase the detection of asymptomatic people with an occlusion of the circle of Willis. Further discussion is needed to determine whether these asymptomatic people with occlusion of the circle of Willis should be considered to have moyamoya disease.
Familial Occurrence
However, there is a possibility that many people who have not been diagnosed with moyamoya disease due to their mild symptoms may be present. These results suggest that familial moyamoya disease is strongly associated with genetic anticipation and female dominance [11].
Age at Onset
Types of Clinical Findings
The distribution of age of onset also showed two peaks, similar to the results observed in Japan. A discrepancy between the age of onset distribution for ischemic and hemorrhagic type was also observed in the Republic of Korea.
World Distribution of Moyamoya Disease
To compare the clinical and epidemiological features of moyamoya disease between the Republic of Korea and Japan, a collaborative study with Korean neurosurgeons was organized as a major project of the RCMJ in 1995 [7]. In this study, 296 definite cases of moyamoya disease were collected from 26 hospitals in the Republic of Korea and compared with 731 definite cases registered in Japan by the RCMJ.
Conclusion
Research Committee on Spontaneous Occlusion of the Circle of Willis (Moyamoya Disease) Kyoto, Japan, p. 15-20. The incidence of the offspring of the proband is approximately 2.4%, which is 34 times higher than in the general population [4].
Mode of Inheritance
Choi The incidence in siblings of a proband with this disease is about 3%, which is 42 times higher than in the general population.
Diagnosis and Clinical Aspect
Research and Genetics on FMMD
Seol HJ, Wang KC, Kim SK et al (2006) Familial occurrence of moyamoya disease: a clinical study. Kitahara T, Ariga N, Yamaura A et al (1979) Familial occurrence of moyamoya disease: report of three Japanese families.
Genetics
Four Lines of Evidence for Involvement of Genetic Factors in the Etiology of Moyamoya Disease
The incidence of moyamoya disease in Japan is therefore estimated to be approximately ten times higher than in Western countries. In patients with Down syndrome, the incidence of moyamoya-like disease is 30 times higher than in the general population [13].
Approaches to Identify the Moyamoya Disease Genes
In Asian Americans, the incidence of moyamoya disease is four times higher than in non-Asian Americans, providing compelling evidence that genetic factors play a dominant role compared to environmental factors [ 11 ]. Abnormal regulation of migration and proliferation of vascular SMCs is hypothesized to underlie the etiology of moyamoya disease [ 21 , 22 ].
Identification of the First Gene Mutated in Moyamoya Disease
Two approaches have been used for the identification of predisposing genes for moyamoya disease: linkage analysis and candidate gene analysis. Candidate gene approaches consist of association and/or mutational analyzes of genes presumed to be functionally related to pathological states of moyamoya disease.
Conclusions
Wakai K, Tamakoshi A, Ikezaki K et al (1997) Epidemiological characteristics of moyamoya disease in Japan: findings from a nationwide survey. Inoue TK, Ikezaki K, Sasazuki T et al (1997) HLA DNA typing in patients with moyamoya disease.
Chromosome 3p24-26
They conducted the case-control study using 28 patients with moyamoya disease and 198 control subjects, and found that the frequency of HLA-B35 allele was significantly increased in patient group compared to the control group (32.1 vs. 10.1%, P < 0.008). The frequency of the HLA allele was most significantly increased among the female patients with late-onset Moyamoya disease.
Chromosome 8q21-22
They concluded that HLA-B35 is a useful genetic marker for moyamoya disease in Republic of Korea. Furthermore, levels of TGF b 1 in serum of patients with moyamoya disease are significantly higher than those of controls [12].
Chromosome 17q25
TGF b 1 gene expression in cultured smooth muscle cells (SMCs) derived from superficial temporal arteries of patients with moyamoya disease was significantly increased compared to those from controls [11]. Peak levels of elastin synthesis and elastin RNA in response to exogenous TGF b 1 were significantly greater in moyamoya SMCs than control SMCs [11].
Chromosome 17q25.3
Hojo M, Hoshimaru M, Miyamoto S et al (1998) Role of transforming growth factor-beta1 in the pathogenesis of moyamoya disease. Kang HS, Kim SK, Cho BK et al (2006) Single-nucleotide polymorphisms of tissue inhibitor of metalloproteinase genes in familial moyamoya disease.
Single Nucleotide Polymorphisms: A Brief Review
Single nucleotide polymorphisms (SNPs) are unique genetic differences between individuals that may contribute to disease susceptibility. Although more than 12 million SNPs have been identified, most of them are not associated with disease susceptibility [1].
Single Nucleotide Polymorphism and Moyamoya Disease
Moyamoya Disease and Single Nucleotide Polymorphisms
Yamauchi T, Tada M, Houkin K et al (2000) Linkage of familial moyamoya disease (spontaneous occlusion of the circle of Willis) to chromosome 17q25. Although the pathogenesis of moyamoya disease (MMD) is still unclear [1], several lines of evidence suggest the involvement of genetic factors in this disease [2].
HLA and Disease Associations
The possible mechanisms of HLA and disease associations are (1) molecular mimicry, (2) the role of HLA molecules acting as receptors for microbes and drugs, and (3) the role of HLA genes as disease-associated markers, closely linked with disease-related non-HLA genes [15]. If the HLA allele significantly associated with a given disease in the first study with a P value of <0.05 shows a significant association in a second study, that HLA allele is considered significantly associated with the disease [ 16].
HLA Studies in MMD
Another important mechanism of HLA-disease associations is the involvement of non-HLA genes closely related to HLA genes in disease pathogenesis. Interestingly, a recent study of the TIMP2 gene in Korean patients with MMD showed a difference in the reported associations of HLA class II alleles with moyamoya disease in Table 2.
Protein, Cell, and Immunology
Because of these limitations, the analysis of peripheral blood and cerebrospinal fluid (CSF) of patients has been an effective tool for investigating the pathogenesis of this disease. This chapter describes the role of proteins, cells and immunity in the pathogenesis of MMD.
Proteins
The rare occurrence and low mortality rate of the disease, the limited availability of surgical specimens from affected internal carotid arteries, and the lack of animal models of MMD represent obstacles to the basic research of MMD.
Proteins, Cells, and Immunity
Similar to bFGF, elevated levels of CRABP-I were also observed in the CSF of patients with cavernous malformations. Notably, the CSF of MMD patients does not show significant increases in the levels of angiogenic factors, including PDGF, TGF-b, interleukin-8, and vascular endothelial growth factor (VEGF), compared to the control group [7].
Cells
Notably, bFGF is significantly elevated in the CSF of patients with Chiari malformation, tethered cord, arteriovenous malformation, and brain tumors [4]. The levels of expression of TGF-b are increased in cultured SMCs derived from superficial temporal arteries and in serum of MMD patients [8].
Immunity
Kim SK, Yoo JI, Cho BK et al (2003) Elevation of CRABP-I in the cerebrospinal fluid of patients with Moyamoya disease. Noda A, Suzuki Y, Takayasu M et al (2000) Elevation of nitric oxide metabolites in the cerebrospinal fluid of patients with moyamoya disease.
Vascular Smooth Muscle Cell-Related Molecules and Cells
Yamamoto M, Aoyagi M, Fukai N et al (1999) Increase in prostaglandin E(2) production by interleukin-1beta in arterial smooth muscle cells derived from patients with moyamoya disease. Yamamoto M, Aoyagi M, Fukai N et al (1998) Differences in cellular responses to mitogens in arterial smooth muscle cells derived from patients with moyamoya disease.
Ischemia/Angiogenesis-Related Molecules Fibroblast Growth Factor
Ischemia/Angiogenesis-Related Molecules and Cells
VEGF and FGF-2 increase the expression of several members of the integrin family in endothelial cells [13]. Therefore, VE-cadherin contributes to the maintenance of the stable monolayer of endothelial cells in the vessel wall.
Ischemia/Angiogenesis-Related Cells Endothelial Progenitor Cells
Rafat N, Beck GCh, Peña-Tapia PG et al (2009) Increased levels of circulating endothelial progenitor cells in patients with Moyamoya disease. Fujimura M, Watanabe M, Narisawa A et al (2009) Increased expression of serum matrix metallo-proteinase-9 in patients with moyamoya disease.
Pathological Evidence
Hepatocyte growth factor, a potent angiogenic factor and inducer of smooth muscle cell migration, is also elevated in the CSF of patients with moyamoya disease [ 11 ]. Proteomic analysis of the CSF of patients with moyamoya disease showed that cellular retinoic acid-binding protein 1 (CRABP-1) was significantly elevated [ 12 ].
Association with Autoimmune Diseases
Although it is difficult to obtain pathologic specimens of affected arteries in patients with moyamoya disease, several autopsy studies have provided a consistent description of the vascular pathology of moyamoya disease. Despite the lack of evidence of immune cell infiltration in the vascular lesions of patients with moyamoya disease, the roles of cytokines in the proliferation and migration of smooth muscle cells have been intensively investigated.
Association with Infectious Diseases
However, the prevalence and significance of detectable APL antibodies are unknown for patients with primary moyamoya disease. It is noteworthy that one of the three patients with APL antibodies in the previous study had Down syndrome as the underlying disease.
Kawasaki, Takayasu, and Moyamoya Disease
Houkin K, Yoshimoto T, Abe H et al (1998) Role of basic fibroblast growth factor in the pathogenesis of moyamoya disease. Greco F, Castellano Chiodo D, Sorge A et al (2006) Multiple arterial ischemic strokes in a child with moyamoya disease and Mycoplasma pneumoniae infection.
Pathophysiology II: Hemodynamics,
Biomechanical Aspect
When the shear force F is applied to a plate, the deformation of the block increases with time, while that of a solid is proportional to the applied shear stress. This is the equation for a parabola, where u = 0 when r = R and a maximum when r = 0 at the center line of the pipe.
Blood Flow in Arteries
To study the hemodynamics of the arterial system, knowledge of the elastic properties of the arterial wall is of fundamental importance. 7 Diagrammatic representation of the concept of input impedance (left) and the representation of modulus (| Z |) and phase (q) (right.
Regional Predilection of Lesions and Stages of Moyamoya Disease
As vessel shear stress decreases, endothelin is secreted, resulting in vascular smooth muscle contraction. This in turn results in narrowing of the vessel diameter as well as increased flow rate.
How Is the Hemodynamics in Distal ICA and/or BA?
In the ICA model of MMD, the predisposing areas of proximal MCA and proximal ACA (points 1 and 2, respectively) and the non-predisposing area of ICA (point 3) were evaluated in light of shear stress (Fig. 2a. In our simulation, points 1 and 2 in the ICA model showed lower values of shear stress.
Could This Hemodynamic Factor of Shear Stress Be an Etiology of This Predilection?
Repeated contraction and relaxation from stimulation can result in proliferation of smooth muscle cells [11]. However, in the future, studies incorporating more complex flow patterns may further improve our understanding of MMD.
How Is the Hemodynamic Change Higher According to the Stage of MMD?
The remodeling of the fluid-solid interface, which reflects the thickness and properties of the vessel wall, can be useful in simulating the dynamic state in MMD. Chiu JJ, Chen LJ, Lee PL et al (2003) Shear stress inhibits the expression of adhesion molecules in vascular endothelial cells induced by coculture with smooth muscle cells.
Clinical Features
Most children with Moyamoya disease develop transient ischemic attacks (TIA) or cerebral infarction, while approximately half of adult patients develop intracranial hemorrhage, and half develop TIA or cerebral infarction, or both. Regarding the ethnic difference, the clinical features and course of moyamoya disease in Caucasians are clearly different from moyamoya disease in Asians in terms of the timing of the onset of vasculopathy and the lower rate of bleeding [2].
Ischemic Attacks
Clinical Features of Moyamoya Disease
Over time, moyamoya disease can remain stable, but more typically follows a progressive course with severe motor impairment and intellectual deterioration [6].
Intracranial Hemorrhage
Seizure, Headache, Involuntary Movement and Other Neurologic Symptoms
Clinical presentation of moyamoya disease includes transient ischemic attack (TIA), cerebral infarction, intracerebral hemorrhage, and seizure [ 2 ]. Recently, headache is also considered as one of the common clinical presentations of moyamoya disease.
Headache as the Common Clinical Presentation of Moyamoya Disease
TIA is one of the most common clinical manifestations of Moyamoya disease in both children and adults [2], while intracerebral hemorrhage occurs mainly in adults [3]. According to the research of the association of patients with Moyamoya disease and their families, this is more than 50%.
Headache and Revascularization Surgery
Although the underlying mechanism and optimal treatment of such headache are not determined, it is believed that decreased cerebral blood flow and the gradual acquisition and redistribution of blood flow are the cause of headache in patients with moyamoya disease. Seol HJ, Wang KC, Kim SK et al. 2005) Headache in pediatric moyamoya disease: a review 204.
Characteristics of the Patients
Involuntary movements are a relatively rare symptom of this condition, with an estimated frequency of 3 to 6% [3–5]. In this chapter, we focus on the involuntary movements caused by moyamoya disease and discuss the patient characteristics, symptoms, underlying mechanisms, and treatment of this condition.
Symptoms
Mechanisms
Treatment
Lyoo CH, Kim DJ, Chang H et al (2007) Moyamoya disease with paroxysmal exercise-induced dyskinesia. Miura T, Kobayashi M, Sonoo M et al (2002) An adult case of moyamoya disease with transient hemichorea.
Angiographical Progression
Moyamoya disease is characterized by progressive stenosis of the terminal part of the internal carotid artery (ICA) and its main branches [1]. Most patients present with intermediate stages and are treated promptly; therefore, the advanced stage is rarely seen nowadays [3].
Age and Progression
Unilateral to Bilateral
Those Who Are Likely to Progress
Angiography showed occlusion of the terminal part of the left internal carotid artery (ICA) and stenosis of the proximal part of the right anterior cerebral artery (ACA). One year later, he developed left hemiparesis, and diffusion-weighted MRI revealed fresh infarction in the right frontal lobe (b.
Mechanism of Progression
MRI fluid-attenuated inversion recovery (FLAIR) image showed ischemic lesion in the left frontal deep white matter (b. Four years later she experienced transient ischemic attack and angiography revealed occlusion of right ACA and left ICA.
Progression of Clinical Sign
Moyamoya disease usually causes some cerebral ischemia in the territory of the ICA, especially in the frontal lobe [21, 22]. There are two main causes of intracranial hemorrhage in Moyamoya disease: rupture of dilated, vulnerable moyamoya vessels or rupture of the saccular aneurysm in the circle of Willis [24].
Imaging Studies to Detect Progression
Therefore, most patients with moyamoya disease present with focal neurological signs, such as dysarthria, aphasia, or hemiparesis. Rebleeding is the most important factor in the poor outcomes of patients with hemorrhagic moyamoya disease and occurs at an increased rate when patients reach the age of 46–55 years [ 25 ].
Influence of Bypass Surgery to Progression
Ezura M, Yoshimoto T, Fujiwara S et al (1995) Clinical and angiographic follow-up of childhood moyamoya disease. Seol HJ, Wang KC, Kim SK et al (2006) Unilateral (probable) moyamoya disease: long-term follow-up of seven cases.
Prevalence of Renal Arterial Involvement in Moyamoya Disease
Moyamoya disease is a rare cerebrovascular occlusive disorder characterized by stenosis or occlusion of the distal internal carotid artery or proximal anterior or middle cerebral arteries, causing the formation of multiple small collateral vascular networks (moyamoya vessels) at the base of the brain [1 – 3].
Systemic Arterial Involvement in Moyamoya Disease
In all six cases, the stenotic lesion was located in the proximal part of the renal artery. In the three patients with moderate stenosis, the renal artery stenosis was located in the proximal region of the main branch.
Radiologic and Pathologic Findings of Renal Arteries Involved in Moyamoya Disease
Treatment of Renovascular Hypertension in Moyamoya Disease
Renovascular hypertension Choi because patients with moyamoya disease occasionally present with renovascular hypertension as the first symptom [21].
Other Extracranial Artery Involvement in Moyamoya Disease
Akasaki T, Kagiyama S, Omae T et al (1998) Asymptomatic moyamoya disease associated with coronary and renal artery stenosis – a case report. Kaczorowska M, Jóźwiak S, Litwin M et al (2005) Moyamoya disease associated with extracranial artery stenosis: case report and literature review.
Akin Moyamoya Disease (Quasi-Moyamoya Disease)
Association with Vascular Malformations
Arteriovenous Malformation
Right frontal arteriovenous malformation was also demonstrated in the feeding veins of the branch of anterior cerebral artery and part of the abnormal vascular network. Since he was diagnosed with asymptomatic, uninterrupted arteriovenous malformation and single-photon emission computed tomography did not detect any hemodynamic compromise, we followed him conservatively every 6 months with outpatient magnetic resonance imaging.
Association with Cavernous Malformation and Venous Malformation
Korematsu K, Yoshioka S, Maruyama T et al (2007) De novo appearance of cerebellar cavernous malformation in a patient with moyamoya disease: case report and literature review. Fujimura M, Watanabe M, Narisawa A et al (2009) Increased expression of serum matrix metalloproteinase-9 in patients with moyamoya disease.
Diagnostic Evaluation I
Morphological Imaging
Digital Subtraction Angiography
CT Scan
However, on CT scan, steno-occlusive change and development of moyamoya vessels are not depicted as the vascular system such as the circle of Willis shows non-specific density. In all cases of supratentorial intracerebral hemorrhage seen on CT scan, hemorrhage due to moyamoya disease should be considered as a differential diagnosis.
Magnetic Resonance Image
Susceptibility-weighted imaging (SWI) can also be very sensitive to these small hemorrhages that do not show up well on a CT scan. 4 Left A small asymptomatic infarct is seen in the right frontal lobe, but this infarct is not specific for moyamoya disease.
Magnetic Resonance Angiography
On the other hand, steno-occlusive changes are often overestimated in MRA (Figures 11 and 12). Right inverted heavy T2-weighted image clearly shows steno-occlusive changes of the middle cerebral artery.
3D-CTA
Yamada I, Suzuki S, Matsushima Y (1995) Moyamoya disease: comparison of evaluation with MR angiography and MR imaging versus conventional angiography. Yamada I, Nakagawa T, Matsushima Y et al (2001) High-resolution turbo magnetic resonance angiography for the diagnosis of Moyamoya disease.
Diagnostic Criteria for Moyamoya Disease with MRA
Quality of MRA for the Diagnosis of Moyamoya Disease
Especially in both the early and end stages of moyamoya disease, the diagnosis by MRA should be carefully evaluated, as in these stages typical findings of steno-occlusive change and the development of moyamoya vessels are not always demonstrated.
Novel Staging of Moyamoya Disease
However, it is well known that the development of the basal vessels of moyamoya is not linearly related to the stage of the disease [ 3 , 23 ]. Evaluation of the moyamoya vessels is indispensable for the primary diagnosis of the disease by MRA.
Postoperative MRA
Suzuki R, Matsushima Y, Takada Y et al (1989) Changes in cerebral hemodynamics after encephalo-duro-arterio-synangiosis (EDAS) in young patients with Moyamoya disease. Houkin K, Nakayama N, Kuroda S et al (2004) How does angiogenesis develop after surgery in pediatric moyamoya disease.
Importance of MRI/MRA for the Management of Moyamoya Disease
The recent advent of magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) has contributed significantly to the diagnosis of moyamoya disease. This section will present the latest knowledge regarding the MRI/MRA findings of moyamoya disease and their contribution to the management of this entity.
Diagnostic Evaluation: Morphological Imaging MRI
According to the guidelines for the diagnosis and treatment of spontaneous occlusion of the circle of Willis, i.e. moyamoya disease, cerebral angiography is not mandatory if MRI and MRA establish all findings necessary for diagnosis [1].
Morphological Evaluation MRI
In the very early stage, MRA shows slight stenosis of the ICA terminal portion (Fig. 5a. As the disease progresses, MRA reveals the typical findings of moyamoya disease, including the steno-occlusive change in the ICA and its tributaries, the development of moyamoya vessels, and an increase in the diameter of the ECA system (Fig. 5b) [21, 40].
Hemodynamic Evaluation
Kuroda S, Ishikawa T, Houkin K et al (2005) Incidence and clinical features of disease progression in adult moyamoya disease. Yoon HK, Shin HJ, Lee M et al (2000) MR angiography of moyamoya disease before and after encephaloduroarteriosynangiosis.
Diagnostic Evaluation II
Functional Imaging
Generally, most pediatric patients who have usually suffered from recurrent TIA may show severe hemodynamic cerebral ischemia such as the misery perfusion [3-5]. The misery perfusion is generally considered to be an impaired cerebral hemodynamics suitable for surgical revascularization [6, 7].
15 O-PET
CBF-SPECT
4 Stratification of hemodynamic cerebral ischemia using quantitative rest and acetazolamide-activated CBF-SPECT (slope of oblique line corresponds to vascular reserve). Therefore, the severity of hemodynamic cerebral ischemia can be classified by the combination of Z-score values estimated from resting and acetazolamide-activated Z-score maps (Table 2.
Perfusion MRI/CT
Ikezaki K, Matsushima T, Kuwabara Y, et al (1994) Cerebral circulation and oxygen metabolism in childhood moyamoya disease: a perioperative positron emission tomography study. Iida H, Akutsu T, Endo K, et al (1996) A multicenter validation of regional cerebral blood flow quantification using [123I] iodoamphetamine and single photon emission computed tomography.
Imaging Techniques
Although the uptake of 99m Tc-HMPAO in the brain is also partly dependent on glutathione activity of the ischemic brain tissues. In brain perfusion SPECT with 99m Tc-HMPAO or 99m Tc-ECD MBq (15–30 mCi) radioactivity is injected in an adult and the injected dose is adjusted according to the body weight in a pediatric patient.
Clinical Applications
In MMD, the characteristic hemodynamic change is 'reduced CVR' in the brain region suppressing the affected cerebral artery, which is demonstrated as increased perfusion on acetazolamide stress SPECT (Fig. 2. Movement disorders such as chorea and dystonia are presented in cases where CBF and CVR is reduced in the striatum [15].
Other Issues with Spect
So Y, Lee HY, Kim SK et al (2005) Prediction of clinical outcome of pediatric moyamoya disease by postoperative basal/acetazolamide stress perfusion brain SPECT after revascularization surgery. Lee JW, Kim YK, Lee SM et al (2008) Assessment of hyperperfusion by brain perfusion SPECT in.
Kinetics of Iomazenil and the Indicator of the Intactness of the Cortical Neurons
Diagnosis of Incomplete Brain Infarction in Moyamoya Disease
An incomplete cerebral infarction defined by 3D-SSP analysis of IMZ-SPECT (Z-score > 2) was observed in the right superior frontal lobe, consistent with persistent stage II ischemia. After the left EC-IC bypass surgery was performed, the severity of hemodynamic cerebral ischemia in the left hemisphere was improved from stage II ischemia to stage I ischemia using SEE analysis.
Diagnosis of Higher Brain Dysfunction in Moyamoya Disease
