Incidence and Clinical Features of Disease Progression in Adult Moyamoya Disease

Significance of Cerebral Blood Flow Analysis in the Acute Stage after Revascularization Surgery for Moyamoya Disease

Moyamoya disease is a chronic, occlusive cerebrovascular disease with unknown etiology characterized by steno-occlusive changes at the terminal portion of the internal carotid artery, either bilaterally or unilaterally, and an abnormal vascular network at the base of the brain. Surgical revascularization such as extracranial-intracranial (EC-IC) bypass is the preferred procedure for moyamoya disease. Despite the favorable long-term outcome, cerebral infarction and hyperperfusion syndrome are potential complications of this procedure, which can lead to neurological deterioration in the acute stage. In light of the similar clinical presentations between perioperative ischemia and hyperperfusion, it is essential to attempt a prompt cerebral blood flow (CBF) measurement in the acute stage after EC-IC bypass for moyamoya disease to differentiate these distinct pathologies, because the management of cerebral ischemia and hyperperfusion is contradictory to each other. Routine CBF analysis by single-photon emission computed tomography and/or magnetic resonance imaging not only facilitated a safer perioperative management but also provided important information about dynamic pathology of the hemodynamic conversion in the acute stage after revascularization surgery for moyamoya disease. We represent the current status of CBF analysis during the perioperative period of revascularization surgery for moyamoya disease, and sought to discuss its significance and efficacy to avoid surgical complications.

Adult Moyamoya Disease: A Burden of Intracranial Stenosis in East Asians?

BACKGROUND

Both Moyamoya disease (MMD) and intracranial atherosclerotic stenosis (ICAS) are more prevalent in Asians than in Westerners. We hypothesized that a substantial proportion of patients with adult-onset MMD were misclassified as having ICAS, which may in part explain the high prevalence of intracranial atherosclerotic stroke in Asians.

METHOD

We analyzed 352 consecutive patients with ischemic events within the MCA distribution and relevant intracranial arterial stenosis, but no demonstrable carotid or cardiac embolism sources. Conventional angiography was performed in 249 (70.7%) patients, and the remains underwent MRA. The occurrence of the c.14429G>A (p.Arg4810Lys) variant in ring finger protein 213 (RNF213) was analyzed. This gene was recently identified as a susceptibility gene for MMD in East Asians.

RESULTS

The p.Arg4810Lys variant was observed in half of patients with intracranial stenosis (176 of 352, 50.0%), in no healthy control subjects (n = 51), and in 3.2% of stroke control subjects (4 of 124 patients with other etiologies). The presence of basal collaterals, bilateral involvement on angiography, and absence of diabetes were independently associated with the presence of the RNF213 variant. Among 131 patients who met all three diagnostic criteria and were diagnosed with MMD, three-fourths (75.6%) had this variant. However, a significant proportion of patients who met two criteria (57.7%), one criterion (28.6%), or no criteria (20.0%) also had this variant. Some of them developed typical angiographic findings of MMD on follow-up angiography.

CONCLUSIONS

Careful consideration of MMD is needed when diagnosing ICAS because differential therapeutic strategies are required for these diseases and due to the limitations of the current diagnostic criteria for MMD.

Moyamoya Biomarkers

Moyamoya disease (MMD) is an arteriopathy of the intracranial circulation predominantly affecting the branches of the internal carotid arteries. Heterogeneity in presentation, progression and response to therapy has prompted intense study to improve the diagnosis and prognosis of this disease. Recent progress in the development of moyamoya-related biomarkers has stimulated marked interest in this field. Biomarkers can be defined as biologically derived agents-such as specific molecules or unique patterns on imaging-that can identify the presence of disease or help to predict its course. This article reviews the current categories of biomarkers relevant to MMD-including proteins, cells and genes-along with potential limitations and applications for their use.

1H-NMR-based metabolomic analysis of cerebrospinal fluid from adult bilateral moyamoya disease: comparison with unilateral moyamoya disease and atherosclerotic stenosis

Although metabolomics has been increasingly used to observe metabolic pattern and disease-specific metabolic markers, metabolite profiling for moyamoya disease (MMD) has not yet been done in adults. This study investigated cerebrospinal fluid (CSF) metabolites specific to bilateral MMD (B-MMD) and compared them to those of unilateral MMD (U-MMD) or atherosclerotic stenosis with hydrogen-1 nuclear magnetic resonance spectroscopy to identify metabolic biomarkers associated with MMD in adults.CSF samples of B-MMD (n = 29), U-MMD (n = 11), and atherosclerotic cerebrovascular disease (ACVD) (n = 8) were recruited. Principal component analysis, partial least square discriminant analysis, and orthogonal projections to latent structure discriminant analysis (OPLS-DA) were done for the comparisons. Diagnostic performance was acquired by prediction of 1 left-out sample from the distinction model constructed with the rest of the samples.B-MMD showed an increase in glutamine (P < 0.001) and taurine (P = 0.004), and a decrease in glucose (P < 0.001), citrate (P = 0.002), and myo-inositol (P = 0.006) than those in ACVD. U-MMD showed a higher level of glutamine (P = 0.005) and taurine (P = 0.034), and a lower level of glutamate (P < 0.004) than those in ACVD. No difference at the metabolite level was observed between B-MMD and U-MMD. Cross-validation with the OPLS-DA model showed a high accuracy for the prediction of MMD.The results of the study suggest that a metabolomics approach may be helpful in confirming MMD and providing a better understanding of MMD pathogenesis. Elevated glutamine in the CSF may be associated with MMD pathogenesis, which was different from ACVD.

Clinical features and disease progression in moyamoya disease patients with Graves disease

OBJECT

The present study aimed to clarify the incidence and clinical features of disease progression in adult moyamoya disease (MMD) patients with Graves disease (GD) for better management of these patients.

METHODS

During the past 18 years, 320 adult Chinese patients at West China Hospital were diagnosed with MMD, and 29 were also diagnosed with GD. A total of 170 patients (25 with GD; 145 without GD) were included in this study and were followed up. The mean follow-up was 106.4 ± 48.6 months (range 6-216 months). The progression of the occlusive lesions in the major intracranial arteries was measured using cerebral angiography and was evaluated according to Suzuki's angiographic staging. Information about cerebrovascular strokes was obtained from the records of patients' recent clinical visits. Both angiographic progression and strokes were analyzed to estimate the incidences of angiographic progression and strokes using Kaplan-Meier analysis. A multivariate logistic regression model was used to test the effects of sex, age at MMD onset, disease type, strokes, and GD on the onset of MMD progression during follow-up.

RESULTS

During follow-up, the incidence of disease progression in MMD patients with GD was significantly higher than in patients without GD (40.0% vs 20.7%, respectively; p = 0.036). The interval between initial diagnosis and disease progression was significantly shorter in MMD patients with GD than in patients without GD (p = 0.041). Disease progression occurred in both unilateral MMD and bilateral MMD, but the interval before disease progression in patients with unilateral disease was significantly longer than in patients with bilateral disease (p = 0.021). The incidence of strokes in MMD patients with GD was significantly higher than in patients without GD (48% vs 26.2%, respectively; p = 0.027). The Kaplan-Meier survival curve showed significant differences in the incidence of disease progression (p = 0.038, log-rank test) and strokes (p = 0.031, log-rank test) between MMD patients with GD and those without GD. Multivariate analysis suggested that GD may contribute to disease progression in MMD (OR 5.97, 95% CI 1.24-33.76, p = 0.043).

CONCLUSIONS

The incidence of disease progression in MMD patients with GD was significantly higher than that in MMD patients without GD, and GD may contribute to disease progression in MMD patients. The incidence of strokes was significantly higher in MMD patients with GD than in patients without GD. Management guidelines for MMD patients with GD should be developed.

Noninvasive method for mapping CVR in moyamoya disease using ASL-MRI

PURPOSE

To project a noninvasive method for mapping cerebrovascular reserve (CVR) in moyamoya disease (MMD) using ASL-MRI.

METHODS

16 MMD patients underwent cerebral blood flow (CBF) examinations by standard ASL-MRI, pulse-wave-synchronized ASL-MRI (pulsy ASL-MRI) which tagged the arterial blood coincident with a peak of a pulse wave, and single photon emission computed tomography (SPECT) imagings with iodine-123-N-isopropyl-p-iodoamphetamine in the resting (rest-IMP) and after acetazolamide challenge (ACZ-IMP). Hemispheric 32-sided cerebral blood flow (CBF) values were measured with normalized CBF maps created from standard ASL-MRI (standard-ASL value), pulsy ASL-MRI (pulsy-ASL value), rest-IMP (rest-IMP value), and ACZ-IMP (ACZ-IMP value). CVR based on rest-IMP and ACZ-IMP values (IMP-CVR) was calculated. ASL-CVR was also calculated on the basis of corrected standard-ASL values and pulsy-ASL values, which were adjusted to the ACZ-IMP values and rest-IMP values, respectively, by the least-squares method. We assessed the relationships between rest-IMP values and pulsy-ASL values, ACZ-IMP values and standard-ASL values, and IMP-CVR and ASL-CVR.

RESULTS

Significant relationships were observed between rest-IMP values and pulsy-ASL values (correlation coefficient (r=0.557, p<0.01)), ACZ-IMP values and standard-ASL values (r=0.825, p<0.01), and IMP-CVR and ASL-CVR (r=0.736, p<0.01).

CONCLUSIONS

ASL-MRI is equivalent to SPECT and that it might serve as a noninvasive method for mapping CVR in MMD.

Asymptomatic moyamoya disease: literature review and ongoing AMORE study

Recent development of a non-invasive magnetic resonance examination has increased the opportunity to identify asymptomatic patients with moyamoya disease who have experienced no cerebrovascular events. However, their clinical features, prognosis, and treatment strategy are still unclear because of small number of subjects and short follow-up periods. Therefore, we have designed Asymptomatic Moyamoya Registry (AMORE) study in Japan. The objectives of this nation-wide, multi-center prospective study are to clarify long-term prognosis of asymptomatic patients with moyamoya disease and to determine the risk factors that cause ischemic and hemorrhagic stroke in them. In this article, we review the published data on asymptomatic moyamoya disease and report the on-going multi-center prospective cohort study, AMORE study. We would like to emphasize the importance to determine the clinical features, prognosis, and treatment strategies of asymptomatic moyamoya disease in very near future.

Moyamoya disease and syndromes: from genetics to clinical management

Moyamoya angiopathy is characterized by a progressive stenosis of the terminal portion of the internal carotid arteries and the development of a network of abnormal collateral vessels. This chronic cerebral angiopathy is observed in children and adults. It mainly leads to brain ischemic events in children, and to ischemic and hemorrhagic events in adults. This is a rare condition, with a marked prevalence gradient between Asian countries and Western countries. Two main nosological entities are identified. On the one hand, moyamoya disease corresponds to isolated moyamoya angiopathy, defined as being “idiopathic” according to the Guidelines of the Research Committee on the Pathology and Treatment of Spontaneous Occlusion of the Circle of Willis. This entity is probably multifactorial and polygenic in most patients. On the other hand, moyamoya syndrome is a moyamoya angiopathy associated with an underlying condition and forms a very heterogeneous group with various clinical presentations, various modes of inheritance, and a variable penetrance of the cerebrovascular phenotype. Diagnostic and evaluation techniques rely on magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) conventional angiography, and cerebral hemodynamics measurements. Revascularization surgery can be indicated, with several techniques. Characteristics of genetic moyamoya syndromes are presented, with a focus on recently reported mutations in BRCC3/MTCP1 and GUCY1A3 genes. Identification of the genes involved in moyamoya disease and several monogenic moyamoya syndromes unraveled different pathways involved in the development of this angiopathy. Studying genes and pathways involved in monogenic moyamoya syndromes may help to give insights into pathophysiological models and discover potential candidates for medical treatment strategies.

Unstable moyamoya disease: clinical features and impact on perioperative ischemic complications

OBJECT

Unstable moyamoya disease, reasonably defined as cases exhibiting either rapid disease progression or repeated ischemic stroke, represents a challenge in the treatment of moyamoya disease. Despite its overall efficacy, direct bypass for such unstable disease remains controversial in terms of safety. This study aims to reveal factors associated with unstable disease and to assess its impact on postoperative silent or symptomatic ischemic lesions.

METHODS

This retrospective cohort study included both pediatric and adult patients with moyamoya disease who had undergone 140 consecutive direct bypass procedures at Kyoto University Hospital. “Unstable moyamoya disease” was defined as either the rapid progression of a steno-occlusive lesion or repeat ischemic stroke, either occurring within 6 months of surgery. The extent of progression was determined through a comparison of the findings between 2 different MR angiography sessions performed before surgery. The clinical variables of the stable and unstable disease groups were compared, and the association between unstable disease and postoperative diffusion-weighted imaging (DWI)–detected lesion was assessed through univariate and multivariate analyses with generalized estimating equations.

RESULTS

Of 134 direct bypass procedures performed after patients had undergone at least 2 sessions of MR angiography, 24 (17.9%) were classified as cases of unstable disease. Age younger than 3 years (p = 0.029), underlying disease causing moyamoya syndrome (p = 0.049), and radiographic evidence of infarction (p = 0.030) were identified as factors associated with unstable disease. Postoperative DWI-defined lesions were detected after 13 of 140 procedures (9.3%), although only 4 lesions (2.9%) could be classified as a permanent complication. The incidence of postoperative DWI-detected lesions in the unstable group was notable at 33.3% (8 of 24). Univariate analysis revealed that unstable disease (p < 0.001), underlying disease (p = 0.028), and recent stroke (p = 0.012) were factors associated with DWI-detected lesions. Unstable disease remained statistically significant after adjustment for covariates in both the primary and sensitivity analyses (primary analysis: OR 6.62 [95% CI 1.79–24.5]; sensitivity analysis: OR 5.36 [95% CI 1.47–19.6]).

CONCLUSIONS

Unstable moyamoya disease, more prevalent in younger patients and those with underlying disease, is a possible risk factor for perioperative ischemic complications. Recognition of unstable moyamoya disease may contribute to an improved surgical result through focused perioperative management based on appropriate surgical risk stratification.

Clinical Features, Surgical Treatment, and Long-Term Outcome in Pediatric Patients with Moyamoya Disease in China

Background: There was few detailed demographic and clinical data about Chinese patients with moyamoya disease. Here we describe the clinical features, surgical treatment, and long-term outcome of pediatric patients with moyamoya disease at a single institution in China. Methods: Our cohort included 288 pediatric patients with moyamoya disease. The demographic and clinical characteristics were obtained by retrospective chart review and long-term outcome was evaluated using the stroke status. Univariate and multivariate logistic regression analyses were performed to determine the risk factors for clinical outcome. The risk of subsequent stroke was determined using the Kaplan-Meier method. Results: The median age for the onset of symptoms was 8.0 years. The ratio of female to male patients was 1:1. Familial occurrence of moyamoya disease was 9.4%. The incidence of postoperative complications was 4.2%. Postoperative ischemic events were identified as predictors of unfavorable clinical outcome, while older age of symptom onset was associated with a favorable clinical outcome. The Kaplan-Meier estimate stroke risk was 5% in the first 2 years, and the 5-year-Kaplan-Meier risk of stroke was 9% after surgery for all patients treated with surgical revascularization. Overall, 86% of patients had an independent life with no significant disability. Conclusion: This long-term survey demonstrated that most surgically treated pediatric patients with MMD maintain good outcomes. Our results indicate that an early diagnosis and active intervention before the establishment of irreversible hemodynamic change are essential to achieve a favorable clinical outcome.

Case Report: A case report of Moyamoya disease in a 36 year old African American woman

Moyamoya is a rare idiopathic progressive vaso-occlusive disease characterized by irreversible condition of main blood vessels to the brain as they enter into the skull. We present a case of 36 year old African American female presenting to the Out Patient Clinic with headache which were on and off for 4-6 months and did not relieve on routine medical therapy. It was associated with weakness on right side for last few days. The patient was investigated with CT Angiogram, diagnosed as Moyamoya disease and operated. She has been followed up for the last 5 years and the patient has not complained of any headaches or focal neurological symptoms.

Headache attack followed by rapid disease progression in pediatric moyamoya disease--how should we manage it?

CASE REPORT

A 4-year-old female was presented at our hospital with frequent right frontal headache attack. She was diagnosed with moyamoya disease and was conservatively followed up. One year later, the frequency of headache gradually decreased. However, follow-up MR imaging revealed that the disease stage markedly progressed in the right side and cerebral infarction occurred in the temporal lobe with atrophy of the right frontal lobe. She underwent direct and indirect revascularization on the right side.

CONCLUSION

Aware of this case, we would like to emphasize that headache may be one subtype of ischemic attacks and require frequent MR follow-up to see the disease course. If there is any sign of disease progression, immediate surgical intervention should be indicated to avoid irreversible brain damage.

Exacerbation of major artery aneurysms after revascularization in patients with moyamoya disease: two case reports

The natural history of aneurysms of the major arteries after revascularization in moyamoya disease has yet to be documented. At our institute, we treated two patients with moyamoya disease-associated aneurysms involving major arteries of the posterior cerebral circulation. The aneurysms became enlarged at an early stage after revascularization, necessitating coil embolization. Although cerebral blood flow was improved in the anterior circulation, revascularization for these patients did not decrease hemodynamic stress in the posterior circulation and was not able to attenuate aneurysmal growth. Therefore, patients with moyamoya disease-associated aneurysms of the major arteries should be carefully monitored after revascularization.

Preliminary study of neurocognitive dysfunction in adult moyamoya disease and improvement after superficial temporal artery-middle cerebral artery bypass

OBJECTIVE

Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disease of unknown etiology. In addition, the neurocognitive impairment of adults with MMD is infrequently reported and, to date, has not been well described. We attempted to determine both the neurocognitive profile of adult moyamoya disease and whether a superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis can improve the neurocognitive impairment in exhibiting hemodynamic disturbance without stroke.

METHODS

From September 2010 through November 2012, 12 patients with angiographically diagnosed MMD underwent STA-MCA anastomosis for hemodynamic impairment. Patients with hypoperfusion and impaired cerebrovascular reserve (CVR) capacity but without evidence of ischemic stroke underwent a cognitive function test, the Seoul Neuropsychological Screening Battery (SNSB). Five patients agreed to undergo a follow-up SNSB test. Data from preoperative and postoperative neurocognitive function tests were compared and analyzed.

RESULTS

Five of 12 patients were enrolled. The median age was 45 years (range, 24-55 years). A comparison of preoperative to postoperative status of SNSB, memory domain, especially delayed recall showed significant improvement. Although most of the domains showed improvement after surgery, the results were not statistically significant.

CONCLUSION

In our preliminary study, large proportions of adult patients with MMD demonstrate disruption of cognitive function. This suggests the possibility of chronic hypoperfusion as a primary cause of the neurocognitive impairment. When preoperative and postoperative status of cognitive function was compared, memory domain showed remarkable improvement. Although further study is needed, neurocognitive impairment may be an indication for earlier intervention with reperfusion procedures that can improve cognitive function.

Surgical outcomes and predictors of stroke in a North American white and African American moyamoya population

BACKGROUND

The majority of moyamoya surgical series have been confined to Asian and pediatric populations. Few have studied demographics, risk factors, and outcomes in adult North American populations.

OBJECTIVE

To examine outcomes after revascularization for moyamoya in white and African American adults and to assess for predictors of recurrent stroke.

METHODS

A retrospective review of 75 non-Asian patients undergoing 110 procedures at the Mayo Clinic was performed. Demographics, known moyamoya associations, cerebrovascular risk factors, and autoimmune diseases were recorded. Primary outcomes for vascular events were assessed with Kaplan-Meier analysis. Fisher exact methods were used to evaluate for associations with recurrent events.

RESULTS

Mean age was 42 years, and mean follow-up was 47 months. Seventy-one of the 75 patients were white. The majority had bilateral disease (n = 49). Perioperative ischemic events occurred in 5 patients (4.5%). The 5- and 10-year event rates were 5.8% and 9.9%. Significant associations were found with a history of thyroid disease (P = .05) and recurrent stroke. A trend was also found between hypertension and autoimmune disease with recurrent stroke.

CONCLUSION

Outcomes were favorable with revascularization in this subset with moyamoya. A significant association between a history of thyroid disease and recurrent stroke was found. Additionally, high prevalences of autoimmune disease, hypertension, and thyroid disease were found in our cohort, suggesting that they may play a role in the pathophysiology and progression of moyamoya disease in this population. A new classification for moyamoya is proposed based on these data.

Expression of cellular retinoic acid-binding protein-I (CRABP-I) in the cerebrospinal fluid of adult onset moyamoya disease and its association with clinical presentation and postoperative haemodynamic change

OBJECTIVE

The elevation of cellular retinoic acid-binding protein-I (CRABP-I) has been suggested as a candidate in the pathogenesis of paediatric moyamoya disease (MMD). However, few studies have addressed CRABP-I in adult onset MMD. The aim of this study was to examine the expression of CRABP-I in the cerebrospinal fluid (CSF) of adult onset MMD, and to evaluate its association with clinical presentation and postoperative haemodynamic change.

METHODS

This study examined the CSF from 103 patients: bilateral MMD, n=58 (56.3%); unilateral MMD, n=19 (18.4%); atherosclerotic cerebrovascular disease (ACVD), n=21 (20.4%); and control group, n=5 (4.9%). The intensity of CRABP-I was confirmed by western blotting and expressed as the median (25th-75th percentile). The differences in CRABP-I expression according to disease entity (unilateral MMD vs bilateral MMD vs ACVD), initial presenting symptoms (haemorrhage vs ischaemia) and postoperative haemodynamic change (vascular reserve in single photon emission CT and basal collateral vessels in digital subtraction angiography) were analysed.

RESULTS

CRABP-I intensities in bilateral MMD (1.45(0.86-2.52)) were significantly higher than in unilateral MMD (0.91(0.78-1.20)) (p=0.044) or ACVD (0.85(0.66-1.11)) (p=0.004). No significant differences were noted based on the initial presenting symptoms (p=0.687). CRABP-I was not associated with improvement in vascular reserve (p=0.327), but with decrease in basal collateral vessels (p=0.023) postoperatively.

CONCLUSIONS

Higher CRABP-I in the CSF can be associated with typical bilateral MMD pathogenesis in adults. Additionally, postoperative basal collateral change may be related to the degree of CRABP-I expression.

Recent advances in moyamoya disease: pathophysiology and treatment

Moyamoya disease is a progressive intracranial arteriopathy characterized by bilateral stenosis of the distal portion of the internal carotid artery and the proximal anterior and middle cerebral arteries, resulting in transient ischemic attacks or strokes. The pathogenesis of moyamoya disease remains unresolved, but recent advances have suggested exciting new insights into a genetic contribution as well as into other pathophysiological mechanisms. Treatment that may halt progression of the disease or even reverse the intracranial arteriopathy is yet to be found. There are strong indications that neurosurgical intervention, through direct, indirect, or combined revascularization surgery, can reduce the risk of ischemic stroke and possibly also cognitive dysfunction by improving cerebral perfusion, although randomized clinical trials have not been performed. Many questions regarding the indication for and timing of surgery remain unanswered. In this review, we discuss recent developments in the pathogenesis and treatment of moyamoya disease.

Involuntary movement in pediatric moyamoya disease patients: consideration of pathogenetic mechanism using neuroimaging studies

PURPOSE

Involuntary movement is a rare symptom of moyamoya disease (MMD). No consensus has been reached regarding its clinical features and pathogenetic mechanism. Therefore, pediatric MMD patients presenting with involuntary movement were retrospectively analyzed, focusing on the image findings.

METHODS

A total of 513 patients who were treated for MMD were reviewed. After exclusion of MMD syndromes and those with accompanying conditions related to involuntary movements, five patients (mean age: 11.6 years, range: 5-13 years) were evaluated.

RESULTS

All of the patients improved their symptoms rapidly after the indirect bypass operations to the contralateral hemisphere. All remained symptom-free during the long follow-up period. Comprehensive evaluation of the preoperative imaging findings failed to suggest a characteristic feature in common, corresponding to the existing hypotheses or a new hypothesis. Only one patient showed infarction preoperatively, and only one patient showed prominently enhanced collateral vessels in the basal ganglia. Although a decrease in vascular reserve was observed in all patients, the location and laterality were nonspecific.

CONCLUSION

There still appears to be confusion regarding the pathogenetic mechanism of involuntary movement in MMD with no repetitive, established imaging features to explain the phenomenon. Nonetheless, with its excellent response to surgical treatment, clinical awareness of this rare symptom of MMD should be emphasized as a differential diagnosis for secondary movement disorder in children.

Moyamoya in Hispanics: not Only in Japanese

Moyamoya disease was first described in 1957 as hypoplasia of the bilateral internal carotid arteries, the characteristic appearance of the associated network of abnormally dilated collateral vessels on angiography was later likened to something hazy, like a puff of cigarette smoke, which, in Japanese, is moyamoya. This paper describes two cases of moyamoya presentations, including moyamoya disease and moyamoya syndrome. Moyamoya may rarely occur in North American Hispanic patients. The presentation can vary significantly and ranges bwtween fulminant outcome and prolonged survival. Awareness about moyamoya and its different presentations may be beneficial for the patients and can improve the outcome.

Treatment of Moyamoya disease in the adult population with pial synangiosis

OBJECT

Surgical treatment of moyamoya disease in the adult population commonly uses direct revascularization, the superficial temporal artery (STA) to middle cerebral artery (MCA) bypass (STA-MCA). Pial synangiosis, a method of indirect revascularization, has been used in adult patients with moyamoya when STA-MCA bypass was not technically feasible. Although the effectiveness of pial synangiosis has been well described in children, only limited reports have examined its role in adult patients with moyamoya disease. In this study the authors report on their experience with pial synangiosis revascularization for this population.

METHODS

The authors reviewed the clinical and radiographic records of all adult patients (≥ 18 years of age) with moyamoya disease who underwent cerebral revascularization surgery using pial synangiosis at a single institution.

RESULTS

From 1985 to 2010, 66 procedures (6 unilateral, 30 bilateral) were performed on 36 adult patients with moyamoya disease. The mean age at surgery was 28.3 years, and 30 patients were female. Twenty-eight patients (77.8%) presented with transient ischemic attacks (TIAs), 24 (66.7%) with stroke, and 3 (8.3%) with hemorrhage. Preoperative Suzuki stage was III or higher in 50 hemispheres (75.8%) and 3 patients had undergone prior treatments to the affected hemisphere before pial synangiosis surgery. Clinical follow-up was available for an average of 5.8 years (range 0.6-14.1 years), with 26 patients (72.2%) followed for longer than 2 years. Postoperative angiography was available for 24 patients and 46 revascularized hemispheres, and 39 (84.8%) of the 46 hemispheres demonstrated good collateral formation (Matsushima Grade A or B). Postoperative complications included 3 strokes, 5 TIAs, and 2 seizures, and there was no hemorrhage during the follow-up period. One patient required additional revascularization surgery 8 months after pial synangiosis.

CONCLUSIONS

Pial synangiosis is a safe and durable method of cerebral revascularization in adult patients with moyamoya and can be considered as a potential treatment option for moyamoya disease in adults.

Contralateral progression and its risk factor in surgically treated unilateral adult moyamoya disease with a review of pertinent literature

BACKGROUND

The fate of the contralateral unaffected side of the surgically treated unilateral moyamoya disease (MMD) in adults has not been well described due to the limited number of cases and the heterogeneous ages and treatment methods. The aim of this study was to evaluate the contralateral angiographic progression rate and its risk factors in homogeneous adult MMD patients who underwent surgical revascularization, with a review of pertinent literature.

METHODS

Forty-one surgically treated unilateral MMD patients were retrospectively evaluated. We reviewed medical and radiological records including data on gender, age, hypertension (HTN), smoking, familial MMD, presenting symptom, surgical method, Suzuki stage, and contralateral progression. Then, we conducted univariate and multivariate analyses to determine risk factors.

RESULTS

Six of the 41 cases (14.6%) exhibited contralateral progression during the mean follow-up of 34 months. Four of those six patients (66.7%) were asymptomatic. Additional revascularization surgery was performed in the two symptomatic patients. The presence of a contralateral angiographic abnormality on initial angiography was a statistically significant risk factor for progression (OR, 49.00; p = 0.04). Younger age at diagnosis (32.7 ± 7.8 years in progression group vs. 42.5 ± 10.3 years in non-progression group, p = 0.046) was statistically significant in the univariate analysis, but age was not a significant factor in the multivariate analysis (p = 0.82). Other variables, such as gender (p = 0.13), HTN (p = 0.24), smoking (p = 0.47), and familial MMD (p = 0.20), did not show statistical significance.

CONCLUSIONS

The presence of a contralateral angiographic abnormality on initial angiography was a significant risk factor for progression in surgically treated unilateral adult MMD. Consequently, patients with contralateral abnormalities should be monitored closely.

Posterior cerebral artery involvement in moyamoya disease: initial infarction and angle between PCA and basilar artery

PURPOSE

Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disease, and progressive involvement of the posterior cerebral artery (PCA) has been reported. However, majority of MMD articles are presenting classic anterior circulation related issues. This study investigates the preoperative factors related to the long-term outcome of posterior circulation in MMD.

METHODS

Retrospective review of 88 MMD patients (166 PCAs in either hemisphere) without symptomatic disease involvement of PCA at initial diagnosis was done. Data at initial diagnosis regarding age, presence of infarction, status of the PCA, type of posterior communicating artery, and the angle between PCA and basilar artery were reviewed. Progressive stenosis of PCA was evaluated by symptom or radiological imaging during follow up.

RESULTS

During an average follow up of 8.3 years, 29 out of 166 (18 %) evaluated PCAs showed progressive disease involvement. The average time of progression from the initial operation was 4.9 years, with the latest onset at 10.8 years. The patients who showed progressive stenosis of the PCA tended to be younger, present with infarction, have smaller angle between PCA and basilar artery, and have asymptomatic stenosis of the PCA at initial presentation. However, multivariate analysis confirmed only the presence of initial infarction and a smaller angle between PCA and basilar artery to be significantly associated with progressive stenosis of PCA.

CONCLUSIONS

Involvement of PCA in MMD may occur in a delayed fashion, years after the completion of revascularization of anterior circulation. Persistent long-term follow-up regarding the posterior circulation is recommended.

A case with unusual stroke and fulminant outcome in a Hispanic male

Patient: Male, 42

Final Diagnosis: Moyamoya disease (MMD)

Symptoms: Aphasia • concentration difficulty • dysarthria • personality change

Medication: —

Clinical Procedure: —

Specialty: Radiology

Spontaneous Recanalization of an Occluded Middle Cerebral Artery in a Patient With Moyamoya

Moyamoya disease is a rare cerebrovascular disorder that is characterized by progressive stenosis of the distal portion of the internal carotid artery and its main branches. Here the authors present the first case of spontaneous recanalization of an occluded middle cerebral artery in a woman with moyamoya who had not undergone surgical or endovascular treatment. Although the exact mechanisms remain unclear, spontaneous recanalization in moyamoya could be considered a possible phenomenon. Thus, the neurosurgeons should always pay attention to the pathological variety of dynamic changes in the cerebrovascular structure in moyamoya.

Moyamoya disease: a case of vanishing cerebral vessels

PURPOSE

To provide an overview of moyamoya disease (MMD) including pathophysiology, epidemiology, clinical presentation, diagnosis, treatment, and prognosis.

DATA SOURCES

Selected clinical and epidemiological studies, review articles, and diagnostic guidelines for MMD.

CONCLUSIONS

MMD is a rare cerebrovascular disease characterized by progressive stenosis of the distal internal carotid arteries and their major branches. The dilated and fragile basal collateral circulations display a "puff of smoke" appearance and thus are called moyamoya vessels. Other unique features of MMD include 2:1 female preponderance and its peak incidence in two age groups: early childhood and adults in their mid-40s. The pathophysiology of MMD is unclear and possible causes include genetic linkage, angiogenesis, autoimmune disease, cranial radiation, and infection of the head and neck. Most patients are symptomatic and may present with ischemic or hemorrhagic strokes, seizure, or headache. The diagnosis depends on clinical presentation and radiographic imaging, and disease progression may be halted with direct or indirect cerebral revascularization.

IMPLICATIONS FOR PRACTICE

It is important to make a correct diagnosis and provide appropriate treatment to reduce the morbidity and mortality associated with MMD. A prompt referral for possible surgical revascularization offers the best chance to reduce additional cerebral injuries and improve clinical outcomes.

Clinical features, surgical treatment and long-term outcome in adult patients with Moyamoya disease in China

BACKGROUND

Moyamoya disease (MMD) develops mostly in Asian countries including Japan, Korea, mainland China and Taiwan. However, there are few detailed demographic and clinical data about Chinese patients with MMD. Currently, the most effective treatment in adult patients with MMD is unknown. There have only been a few small case series reporting on encephaloduroarteriosynangiosis (EDAS) in an adult population. Here we describe the clinical features, surgical treatment and long-term outcome of adults with MMD treated at a single institution in China.

METHODS

Our cohort included 470 adult patients with MMD. The demographic and clinical characteristics were obtained by retrospective chart review and long-term outcome was evaluated using the stroke status. The modified Rankin Scale (mRS) was used to determine the neurological functional outcome. Univariate and multivariate logistic regression analyses were performed to determine risk factors for postoperative morbidity and functional outcome. The risk of subsequent stroke was determined using the Kaplan-Meier method and Cox regression was used to determine risk factors for postoperative or subsequent strokes.

RESULTS

The median age for the onset of symptoms was 36.8 (range, 18-59) years. The ratio of female to male patients was 1:1 (231/239). Familial occurrence of MMD was 2.3%. The most common initial symptom was a cerebral ischemic event. The incidence of postoperative ischemic events or hemorrhage was 5.9% (9.8% of patients). Older age at symptom onset, posterior cerebral artery (PCA) involvement and the presence of transient ischemic attack (TIA) were identified as predictors of adverse postoperative events. The Kaplan-Meier estimate stroke risk was 10.1% in the first 2 years, and the 5-year Kaplan-Meier risk of stroke was 13% after surgery for all patients treated with surgical revascularization. Older age at symptom onset, PCA involvement and the presence of TIA were identified as predictors of postoperative or subsequent strokes. Overall, 73.2% of patients had an independent life with no significant disability, with the strongest predictor being the preoperative mRS score.

CONCLUSION

Clinical characteristics of adult MMD in China are different from those in other Asian countries. EDAS in adult patients with MMD carries a low risk, is effective at preventing future ischemic events and improves quality of life.

Discovery of asymptomatic moyamoya arteriopathy in pediatric syndromic populations: radiographic and clinical progression

OBJECT

Limited data exist to guide management of incidentally discovered pediatric moyamoya. Best exemplified in the setting of unilateral moyamoya, in which the unaffected side is monitored, this phenomenon also occurs in populations undergoing routine surveillance of the cerebral vasculature for other conditions, such as sickle cell disease (SCD) or neurofibromatosis Type 1 (NF1). The authors present their experience with specific syndromic moyamoya populations to better characterize the natural history of radiographic and clinical progression in patients with asymptomatic moyamoya.

METHODS

The authors performed a retrospective review of the clinical database of the neurosurgery department at Children's Hospital Boston, including both nonoperative referrals and a consecutive series of 418 patients who underwent surgical revascularization for moyamoya disease between 1988 and 2010.

RESULTS

Within the period of time studied, 83 patients were asymptomatic at the time of radiographic diagnosis of moyamoya, while also having either unilateral moyamoya or moyamoya in association with either SCD or NF1. The mean age at presentation was 9.1 years (range 1-21 years), and there were 49 female (59%) and 34 male (41%) patients. The mean follow-up duration was 5.4 ± 3.8 years (mean ± SD), with 45 patients (54%) demonstrating radiographic progression and 37 (45%) becoming symptomatic within this period. Patients with SCD had the highest incidence of both radiographic (15 patients [75%]) and clinical (13 patients [65%]) progression, followed by NF1 (20 patients [59%] with radiographic progression and 15 patients [44%] with clinical progression) and patients with unilateral moyamoya (10 patients [35%] with radiographic progression and 9 patients [31%] with clinical progression).

CONCLUSIONS

Radiographic progression occurred in the majority of asymptomatic patients and generally heralded subsequent clinical symptoms. These data demonstrate that moyamoya is a progressive disorder, even in asymptomatic populations, and support the rationale of early surgical intervention to minimize morbidity from stroke.

Long-term follow-up results in 142 adult patients with moyamoya disease according to management modality

BACKGROUND

To clarify the most beneficial treatment of the management modality based on our experience with adult moyamoya disease (MMD).

METHODS

From 1998 to 2010, clinical results of 142 patients (ischemic, 98; hemorrhagic, 44) with adult MMD were investigated according to management modality. Revascularization surgery (direct, indirect, and combined bypass) was performed in 124 patients. We observed the clinical course of 18 patients who were treated conservatively. Clinical outcome, angiographic features, hemodynamic change, and incidence of recurrent stroke were investigated pre- and postoperatively.

RESULTS

In patients with ischemic MMD, direct and combined bypasses were more effective treatments to prevent recurrent ischemic stroke than indirect bypass surgery (P < 0.05). In patients with hemorrhagic MMD, rebleeding was less likely to occur in patients who had undergone bypass surgery. However, no significant difference was observed in the rebleeding rate between patients with and without revascularization surgery (P > 0.05). An angiogram after bypass surgery comparing the extent of revascularization and reduction of moyamoya vessels in patients treated with direct, indirect, and combined bypass showed a significant difference (P < 0.05) in favor of direct and combined bypass. Postoperative angiographic changes and SPECT results demonstrated significant statistical correlation (P < 0.05).

CONCLUSION

Revascularization surgery was effective in further ischemic stroke prevention to a statistically significant extent. Direct and combined bypasses were more effective to prevent recurrent ischemic stroke than indirect bypass. However, there is still no clear evidence that revascularization surgery significantly prevents rebleeding in adult MMD patients. More significant angiographic changes were observed in direct and combined bypasses compared with indirect bypass.

Hemorrhage and risk of further hemorrhagic strokes following cerebral revascularization in Moyamoya disease: A review of the literature

Background:

We sought to review the current literature with regards to future risks of hemorrhage following cerebral revascularization in Moyamoya disease (MMD).

Methods:

We performed a comprehensive literature review using PubMed to inspect the available data on the risk of hemorrhage after revascularization in MMD.

Results:

In this review, we identify the risk factors associated with hemorrhage in MMD both before and after cerebral revascularization. We included proposed pathophysiology of the hemorrhagic risk, role of the type of bypass performed, treatment options, and future needs for investigation.

Conclusions:

The published cases and series of MMD treatment do show a risk of hemorrhage after treatment with either direct or indirect bypass both in the immediate as well as long-term future. While there are no discernible patterns in the rate of these hemorrhages, there is Class III evidence for the predictive effect of multiple microbleeds on preoperative imaging. Also, whereas revascularization, both direct and indirect, has been shown to reduce ischemic complications from MMD, there is not an association with the risk of hemorrhage after the procedure. Further studies need to be performed to help evaluate what the risk factors are and how to counsel patients as to the long-term outlook of this disease process.

Spontaneous occlusion of the circle of Willis in a young woman with epilepsy: epileptic-type Moyamoya disease

The authors report a case of a 31-year-old woman from India with history of seizure disorder who presented with sudden onset right hemiparesis and right-sided upper motor neuron type facial palsy. No identifiable risk factors were noted on admission and all laboratory investigations were negative. MR angiography helped in arriving at the diagnosis of moyamoya disease as the aetiology of her symptoms.

Cerebral microbleeds in patients with moyamoya-like vessels secondary to atherosclerosis

OBJECTIVE

Hemorrhagic risk is unknown in patients with moyamoya-like vessels associated with atherosclerotic intracranial cerebral artery occlusion. This study was undertaken to investigate the association between moyamoya-like vessels and cerebral microbleeds (CMBs) in patients with atherosclerotic steno-occlusive disease.

METHODS

The study population comprised 34 patients with steno-occlusive lesions in the intracranial cerebral artery caused by atherosclerosis. We evaluated the presence of moyamoya-like vessels at the base of the brain by cerebral angiography, and the presence of CMBs by T2*-weighted MRI. Patients were divided into 2 groups: those with and those without moyamoya-like vessels; clinical histories and the incidence of CMBs were compared between the groups.

RESULTS

Sixteen patients had moyamoya-like vessels. Twelve of 16 patients with moyamoya-like vessels had a history of ischemic stroke or transient ischemic attack, whereas only 1 patient had a history of symptomatic cerebral hemorrhage. The incidence of CMBs did not differ between the 2 groups (31% vs. 28%, p=0.82). The location of CMBs varied and was not associated with the site of moyamoya-like vessels.

CONCLUSION

CMBs were not associated with moyamoya-like vessels in patients with atherosclerotic cerebral artery occlusion. These patients may not have a high risk of cerebral hemorrhage.

Clinical and immunopathological features of Moyamoya disease

BACKGROUND

Moyamoya disease (MMD) is a cerebrovascular disease characterized by progressive stenosis or occlusion of the terminal portion of internal carotid arteries and the formation of a vascular network at the base of the brain. The pathogenesis of MMD is still unclear.

METHODOLOGY/PRINCIPAL FINDINGS

We retrospectively analyzed clinical data for 65 consecutive patients with MMD in our institutions and evaluated the histopathological and immunohistochemical findings of intracranial vessels from 3 patients. The onset age distribution was found to have 1 peak at 40-49 year-old age group, no significant difference was observed in the female-to-male ratio (F/M = 1.2). Intracranial hemorrhage was the predominant disease type (75%). Positive family history was observed in 4.6% of patients. Histopathological findings were a narrowed lumen due to intimal fibrous thickening without significant inflammatory cell infiltration, and the internal elastic lamina was markedly tortuous and stratified. All 3 autopsy cases showed vacuolar degeneration in the cerebrovascular smooth muscle cells. Immunohistochemical study showed the migration of smooth muscle cells in the thickened intima, and aberrant expression of IgG and S100A4 protein in vascular smooth muscle cells. The Complement C3 immunoreactivity was negative.

CONCLUSION/SIGNIFICANCE

This study indicated that aberrant expression of IgG and S100A4 protein in intracranial vascular wall of MMD patients, which suggested that immune-related factors may be involved in the functional and morphological changes of smooth muscle cells, and finally caused the thickened intima. A possible mechanism is that deposits of IgG in the damaged internal elastic lamina may underlie the disruption of internal elastic lamina, which facilitated S100A4 positive SMCs migrated into intima through broken portions of the internal elastic lamina, resulting in lumen stenosis or occlusion, leading to compensatory small vessels proliferation.

Moyamoya disease in China: its clinical features and outcomes

BACKGROUND AND PURPOSE

Here we describe the clinical features and outcomes of patients with moyamoya disease who were surgically treated at a single institution in China.

METHODS

Our cohort included 802 patients with moyamoya disease. Demographic and clinical characteristics were obtained by retrospective chart review; follow-up information and outcome were obtained through clinical visits, telephone, or letter interview. We used the Kaplan-Meier methods to estimate stroke risk by treatment status.

RESULTS

The median age for the onset of symptoms was 28 (range, 0.5-77) years. Two definite peaks in age distribution were found. The ratio of women to men was 1:1 (398/404). Familial occurrence of moyamoya disease was 5.2%. The initial symptom was ischemia, hemorrhage, or others in 564, 113, and 125 patients, respectively. Twenty-nine of the 802 patients (3.6%) received conservative management. The remaining 773 patients (96.4%) underwent neurosurgical revascularization procedures, and 502 of these were bilateral. The median follow-up after surgery (n=773) or conservative management (n=26) was 26.3 months (range, 6.0-101.9 months). Most subsequent ischemic events appeared in the first 2 years after surgery. The Kaplan-Meier estimated stroke risk was 10.1% in the first 2 years, and the 5-year-Kaplan-Meier risk of stroke was 12.7% after surgery for all patients treated with surgical revascularization.

CONCLUSIONS

This study on the clinical features of moyamoya disease in mainland China indicated bimodal incidence distribution with women-to-men ratios of 1:1 and lower rate of hemorrhages in adults compared with in children. Patients had low rates of postoperative ischemic or hemorrhagic strokes, and the majority of patients had preserved functional status after revascularization.

Focal time-to-peak changes on perfusion MRI in children with Moyamoya disease: correlation with conventional angiography

BACKGROUND

Moyamoya disease is a chronic progressive steno-occlusion of the distal internal carotid arteries with unknown etiology. As the classical presentation of childhood Moyamoya disease is ischemic stroke, cerebral hemodynamic evaluation is important for patient selection for surgery to prevent recurrent ischemic attacks. Perfusion MR imaging has been applied to evaluate cerebral hemodynamics.

PURPOSE

To correlate the 'basal time-to-peak preservation sign', 'auto-synangiosis sign', and 'posterior involvement sign' on time-to-peak map of perfusion MRI with catheter angiography.

MATERIAL AND METHODS

Thirty-four children (6.91 ± 3.08 years) with Moyamoya disease who underwent both perfusion-weighted MRI and catheter angiography were enrolled in this study. Given catheter angiography as a reference standard, basal time-to-peak preservation sign, auto-synangiosis sign, and posterior involvement sign were evaluated on time-to-peak maps.

RESULTS

The basal time-to-peak preservation sign was accurate for the diagnosis of childhood Moyamoya disease; both sensitivity and specificity were 100%. The auto-synangiosis sign showed lower sensitivity (65%), however, with an acceptable specificity (98%). The posterior involvement sign showed lower sensitivity (61%) but had an acceptable specificity (96%).

CONCLUSION

The basal time-to-peak preservation sign may be a universal finding in childhood Moyamoya disease. The auto-synangiosis and posterior involvement sign may be useful in determining transdural collateral status and posterior circulation involvement in childhood Moyamoya disease.