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Background: The gold standard for evaluation of the severity of moyamoya vasculopathy is the Suzuki grade determined with cerebral catheter angiography (CA). With greater use of magnetic resonance angiography (MRA) it is important to understand if MRA is truly comparable to CA., Methods: Children with moyamoya were evaluated using the Suzuki score for CA and the modified MRA six-stage Suzuki score to describe the angiographic findings in moyamoya from initial narrowing of the distal internal carotid artery to the "puff of smoke" appearance of the lenticulostriate collaterals and finally to the disappearance of this network of collaterals. Using Cohen kappa we compared Suzuki grade based on CA with MRA in the same patients., Results: A total of 27 children with moyamoya were reviewed. We calculated a weighted Cohen kappa of 0.49 (P < 0.0001), which is a moderate correlation., Conclusions: We suggest caution in the reliance on MRA for the diagnosis and evaluation of severity of moyamoya in children., Competing Interests: Declaration of competing interest Nothing to report., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Moyamoya is a progressive, non-atherosclerotic cerebral arteriopathy that may present in childhood and currently has no cure. Early diagnosis is critical to prevent a lifelong risk of neurological morbidity. Blood-oxygen-level-dependent (BOLD) MRI cerebrovascular reactivity (CVR) imaging provides a non-invasive, in vivo measure of autoregulatory capacity and cerebrovascular reserve. However, non-compliant or younger children require general anesthesia to achieve BOLD-CVR imaging., Objective: To determine the same-day repeatability of BOLD-CVR imaging under general anesthesia in children with moyamoya., Materials and Methods: Twenty-eight examination pairs were included (mean patient age = 7.3 ± 4.0 years). Positive and negatively reacting voxels were averaged over signals and counted over brain tissue and vascular territory. The intraclass correlation coefficient (ICC), Wilcoxon signed-rank test, and Bland-Altman plots were used to assess the variability between the scans., Results: There was excellent-to-good (≥ 0.59) within-day repeatability in 18 out of 28 paired studies (64.3%). Wilcoxon signed-rank tests demonstrated no significant difference in the grey and white matter CVR estimates, between repeat scans (all p-values > 0.05). Bland-Altman plots of differences in mean magnitude of positive and negative and fractional positive and negative CVR estimates illustrated a reasonable degree of agreement between repeat scans and no systematic bias., Conclusion: BOLD-CVR imaging provides repeatable assessment of cerebrovascular reserve in children with moyamoya imaged under general anesthesia., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Moyamoya disease is a major arteriopathy characterised by progressive steno-occlusion of the arteries of the circle of Willis. Studies in adults with moyamoya suggest an association between abnormal fronto-parietal and white matter regional haemodynamics and cognitive impairments, even in the absence of focal infarction. However, these associations have not been investigated in children with moyamoya. We examined the relationship between regional haemodynamics and ratings of intellectual ability and executive function, using hypercapnic challenge blood oxygen level-dependent magnetic resonance imaging of cerebrovascular reactivity in a consecutive cohort of children with confirmed moyamoya. Thirty children were included in the final analysis (mean age: 12.55 ± 3.03 years, 17 females, 15 idiopathic moyamoya and 15 syndromic moyamoya). Frontal haemodynamics were abnormal in all regardless of stroke history and comorbidity, but occipital lobe haemodynamics were also abnormal in children with syndromic moyamoya. Executive function deficits were noted in both idiopathic and syndromic moyamoya, whereas intellectual ability was impaired in syndromic moyamoya, even in the absence of stroke. Analysis of the relative effect of regional abnormal haemodynamics on cognitive outcomes demonstrated that executive dysfunction was predominantly explained by right parietal and white matter haemodynamics independent of stroke and comorbidity, while posterior circulation haemodynamics predicted intellectual ability. These results suggest that parietal and posterior haemodynamics play a compensatory role in overcoming frontal vulnerability and cognitive impairment., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Given the expanding evidence of clinico-radiological differences between moyamoya disease (MMD) and moyamoya syndrome (MMS), we compared the clinical and radiographic features of childhood MMD and MMS to identify predictors of ischemic event recurrence., Methods: We reviewed a pediatric moyamoya cohort followed between 2003 and 2019. Clinical and radiographic characteristics at diagnosis and follow-up were abstracted. Comparisons between MMD and MMS as well as between MMD and two MMS subgroups (neurofibromatosis [MMS-NF1] and sickle cell disease [MMS-SCD]) were performed., Results: A total of 111 patients were identified. Patients with MMD presented commonly with transient ischemic attacks (TIAs) (35 % MMD versus 13% MMS-NF1 versus 9.5% MMS-SCD; P = 0.047). Symptomatic stroke presentation (MMD 37% versus MMS-NF1 4% versus 33%; P = 0.0147) and bilateral disease at diagnosis (MMD 73% versus MMS-NF1 22 % versus MMS-SCD 67%; P = 0.0002) were uncommon in MMS-NF1. TIA recurrence was common in MMD (hazard ratio 2.86; P = 0.001). The ivy sign was absent on neuroimaging in a majority of patients with MMS-SCD (MMD 67% versus MMS-NF1 52% versus MMS-SCD 9.5%; P = 0.0002). Predictors of poor motor outcome included early age at diagnosis (odds ratio [OR] 8.45; P = 0.0014), symptomatic stroke presentation (OR 6.6; P = 0.019), and advanced Suzuki stage (OR 3.59; P = 0.019)., Conclusions: Moyamoya exhibits different phenotypes based on underlying etiologies. Frequent TIAs is a common phenotype of MMD and symptomatic stroke presentation a common feature of MMD and MMS-SCD, whereas unilateral disease and low infarct burden are common in MMS-NF1. In addition, absence of ivy sign is a common phenotype in MMS-SCD., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Aim:   Moyamoya vasculopathy is characterized by progressive stenosis of the major arteries of the Circle of Willis, resulting in compromised cerebral blood flow and increased risk of stroke. The objectives of the current study were to examine intellectual and executive functioning of children with moyamoya and to evaluate the impact of moyamoya type, stroke (clinical or silent), vasculopathy laterality, and disease duration on neurocognitive abilities., Method:   Thirty pediatric participants (mean age 10 y 10 mo, SD 4 y; 18 females, 12 males) completed age-appropriate Wechsler Intelligence Scales before any therapeutic revascularization procedures. Reports of executive function were obtained from parents and teachers using the Behavior Rating Index of Executive Function., Results:   Children with moyamoya scored significantly lower than the test standardization samples on all indices of intelligence and ratings of executive functioning (p<0.001). Patients did not differ by type of moyamoya or history of stroke. Patients with bilateral disease and stroke scored significantly lower than those with unilateral disease on measures of overall intellectual function (p=0.035) and verbal comprehension (p=0.04). Deficits in metacognitive executive functions were also more pronounced in bilateral patients according to teacher ratings., Interpretation:   Children with moyamoya are at risk for intellectual and executive problems, exacerbated by bilateral disease and clinical stroke history., (© The Authors. Developmental Medicine & Child Neurology © 2011 Mac Keith Press.)