Clinical and Angiographic Features of Patients with Moyamoya Disease and the p.R4810K Heterozygous Variant.

OBJECTIVE

To elucidate the clinical and angiographic features in patients with moyamoya disease (MMD) and the p.R4810K heterozygous variant and present an angiographic grading system to evaluate disease severity.

METHODS

We retrospectively reviewed 87 patients with MMD and the p.R4810K variant treated at Beijing Tiantan Hospital. Clinical features, stroke subtype, and angiographic characteristics were analyzed.

RESULTS

The median age at diagnosis was 25 years (range, 3-59). The ratio of women to men was 1.2:1. The familial occurrence of MMD was 14.9%. The primary symptom at diagnosis was ischemia, hemorrhage, or other in 67, 16, and 4 patients, respectively. Angiographic features correlating with ischemic stroke or stroke, including Suzuki grade, external carotid artery collaterals, leptomeningeal collaterals, and Mugikura grade, were identified. A binary logistic regression model demonstrated a significant correlation of Suzuki grade (P = 0.008) and posterior cerebral artery grade (P = 0.029) with ischemic stroke (142 hemispheres). A modified Suzuki-Mugikura grading system was developed. The areas under the receiver operating characteristic curves used to predict ischemic stroke based on the Suzuki grading, Mugikura grading, and modified Suzuki-Mugikura grading systems were 0.736, 0.69, and 0.741, respectively. Furthermore, the modified Suzuki-Mugikura grades were significantly correlated with infarction in posterior circulation and the number of infarcted regions.

CONCLUSIONS

The clinical and angiographic features of a Chinese MMD population with the p.R4810K variant were similar to those of a Japanese MMD population; they might be a distinct cerebrovascular disease entity and represent a separate subgroup. A modified Suzuki-Mugikura grading system was valuable for predicting stroke and evaluating disease severity.