To analyze clinical characteristics extracranial stenosis of internal carotid artery (ICA) in moyamoya disease (MMD).

The cases of MMD admitted to Peking University International Hospital from January 1, 2018 to September 30, 2019 were retrospectively analyzed. A total of 177 patients with MMD were included. Further analysis included basic data including age, sex, presence of hemorrhage, presence of a new infarction after surgery. The angiographic data were also analyzed, including Suzuki stage, moyamoya vessel volume, ICA stenosis, and posterior cerebral artery (PCA) lesions. CT perfusion (CTP) was analyzed by a pre-infarction staging system. Spearman's correlation was used to analyze the corre lation of intracranial stenosis of internal carotid artery with the above date.

There were 43 children and 134 adults included. A total of 83 sides of ICA had extracranial stenosis, accounting for 23.45% of all sides. All of the stenosis of the extracranial ICA were whole-course (non-focal). ICA stenosis was positively correlated with age, Suzuki stage, CTP grading, and PCA lesion, with correlation coefficients of (r=0.122, P=0.020; r=0.333, P＜0.001; r=0.373, P＜0.001; r=0.131, P=0.010) respectively. High resolution magnetic resonance imaging (Hr-MRI) examination showed that the stenosis was centripetal without plaque formation.

As an independent part of MMD, extracranial ICA stenosis should be paid more attention to. The typical characteristics of stenosis are whole course, uniform distribution and centripetal stenosis. Hr-MRI has important significance in examining extracranial stenosis of ICA. The higher the Suzuki staging, the greater the likelihood of extracranial carotid stenosis. But stenosis was also seen in Suzuki's early stage. The stenosis may result in decreased cerebral perfusion, which exacerbates the symptoms.