Western Moyamoya Phenotype: A Scoping Review

A Case of Moyamoya Vasculopathy Presenting as Simultaneous Ischemic and Hemorrhagic Strokes

Background

Moyamoya disease (MMD) is a rare pathological state characterized by progressive stenosis of the terminal portion of the internal carotid arteries (ICA). Complications include both ischemic and hemorrhagic strokes, for which there is no curative treatment for MMD. Early diagnosis with surgical intervention is vital for there is no definitive treatment. Due to the bimodal age distribution, moyamoya should be considered for patients presenting with stroke and supraclinoid ICA vasculopathy.

Case

We present a case of a 23-year-old female who presented with left arm weakness and sudden onset thunderclap headache. Upon further questioning, it was revealed that the patient had started an estrogen-containing birth control two weeks prior to presentation. Neuroimaging at our tertiary care center demonstrated simultaneous ischemic and hemorrhagic strokes in the bilateral hemispheres associated with vasculopathy seen in both invasive and noninvasive cerebrovascular imaging. She was diagnosed with idiopathic moyamoya disease since her serum and cerebrospinal fluid studies did not reveal any obvious precipitators to suggest moyamoya syndrome (MMS).

Conclusion

There were no obvious precipitating factors identified in the extensive workup for this patient. Therefore, further secondary prevention is difficult for this otherwise young and healthy individual. While there is data to support the use of antiplatelet medications for the prevention of ischemic stroke secondary to intracranial atherosclerotic disease, there are no clear guidelines for the treatment of MMD that simultaneously causes ischemic and hemorrhagic stroke. Further research on the pathophysiology and treatment modalities for MMD are needed to guide clinicians in treating this complex disease.

Moyamoya disease in Southeast Asians: genetic and autopsy data, new cases, systematic review, and meta-analysis of all patients from the literature

BACKGROUND

Moyamoya disease (MMD) is a rare disorder causing ischemic and hemorrhagic juvenile stroke. It is associated with the founder susceptibility variant p.R4810K in the RNF213 gene in East Asia. Our aim was to enhance understanding of MMD in so far poorly characterized Southeast Asians and exploring differences with Caucasian Europeans.

METHODS

By retrospective analysis of medical records and systematic database search on PubMed for all published cases, we identified Southeast Asian patients with MMD. We extracted and pooled proportions using fixed-effects models. Our own cohort was tested for the East Asian RNF213 founder variant p.R4810K. One of our Southeast Asian patients underwent post-mortem histopathological examination.

RESULTS

The study cohort comprised 32 Southeast Asians. Mean age at onset in the entire cohort was 32.5 ± 20.3 years (n = 24), 43.4 ± 8.7 years in patients admitted to our center (n = 11), and 23.4 ± 22.4 years in patients from the international literature (n = 13). Female-to-male ratio was 1.6:1. MMD predominantly affected bilateral anterior intracranial vessels. Cerebral ischemia outnumbered transient ischemic attacks (TIAs) and intracranial hemorrhage. TIAs, arterial hypertension and obesity were significantly less frequent in Southeast Asian patients compared to Caucasian Europeans. p.R4810K was absent in all examined Southeast Asians despite of typical histopathological signs of MMD in one autopsy case.

CONCLUSION

Clinical and histopathological manifestations of MMD in Southeast Asians are similar to those in Caucasian Europeans. The genotype of MMD in Southeast Asians differs from that of most East Asian patients.

[Moyamoya in Aragon: epidemiology and self-perception of quality of life]

INTRODUCTION

Moyamoya angiopathy is a vasculopathy caused by stenosis/occlusion of one or both intracranial internal carotid arteries. Although more common in Eastern countries, its prevalence is increasing in the West. An angioresonance or angiography is essential for its diagnosis. There are two options for treatment: conservative (medical) treatment or surgical bypass techniques.

PATIENTS AND METHODS

Nineteen patients were selected using International Classification of Diseases codes, and their demographic characteristics and health outcomes were studied. They were administered a scale for the screening of anxious-depressive syndrome (the Hospital Anxiety and Depression Scale - HADS) and another scale for self-perceived quality of life (SF-36). After applying the inclusion/exclusion criteria, eight of these patients were studied.

RESULTS

Nineteen patients were studied (52.63% male, 57.89% European) and the Aragonese prevalence was estimated at 1.37/100,000 inhabitants. The most frequent clinical presentation was ischaemic stroke (73.68%). The HADS detected two positive cases of anxiety and one case of depression. According to the SF-36, the worst self-rated aspects were vitality (median: 35/100) and general health (median: 42.5/100), while the best rated was physical function (mean: 93.57/100).

CONCLUSIONS

This is the Spanish series with the highest prevalence and the only one that addresses self-perceived health and screening of the anxious-depressive syndrome. Further research is needed to address this entity and determine its true prevalence in the West.

Ethnic-Associated Phenotype Variations in Moyamoya Cerebrovascular Outcomes

INTRODUCTION

Moyamoya has been extensively described in East Asian populations, and despite its accepted clinical presentation and course, it is fundamental to describe major cerebrovascular complications in other ethnically diverse samples. Hence, we sought to determine if distinct ethnic groups are at higher risk of developing stroke using the National Inpatient Sample (NIS) database.

METHODS

We included all moyamoya patients admitted from January 2013 until December 2018 in the NIS database. Multivariate regression analysis was used to determine the risk of developing stroke and poor outcomes in different races compared to white patients.

RESULTS

Out of the 6093 admissions with diagnosis of moyamoya disease that were captured, 2,520 were white (41.6%), 2,078 were African American (AA) (34.1%), 721 were Hispanic (11.8%), and 496 were Asian (8.14%). For arterial ischemic stroke (AIS), we found that AA race had a significantly reduced risk of AIS compared to white patients (odds ratio = 0.8, 95% confidence interval: 0.7-0.9, p = 0.031). While being Hispanic or Asian significantly increased 1.5 and 2-fold the risk of hemorrhagic stroke.

CONCLUSION

This study highlights the unique features and phenotypes of moyamoya cases among different ethnicities. While possibly AA are protected from developing AIS due to underlying causes of moyamoya such as sickle cell disease, Asians seems to be more susceptible to hemorrhagic stroke.