The "mustache sign": a radiographic biomarker of angiogenic potential in advanced moyamoya disease.

Abstract

Objective: Moyamoya disease (MMD) is a progressive arteriopathy of intracranial internal carotid arteries. The authors identified a characteristic angiographic finding associated with arterio-arterial collaterals in which ischemic brain recruits blood supply from the posterior circulation with robust splenial-to-anterior pericallosal artery anastomoses, manifesting as a characteristic "mustache" appearance on an anterior-posterior angiogram projection. In this paper, a cohort of pediatric patients with MMD is presented to assess the utility of this finding as a potential marker of disease severity and angiogenic potential and its predictive value for surgical intervention.

Methods: A retrospective single-center review of pediatric patients with MMD who underwent bilateral surgical revascularization from 2014 to 2020 was performed. The presence of a mustache sign was determined and its presence or absence was correlated with Suzuki and Matsushima grades and clinical outcome.

Results: A total of 100 pediatric patients (200 total hemispheres) with MMD were identified (mean age 11 [SD 7] years). Of the total hemispheres, 12% exhibited a low Suzuki grade (I or II) with the remainder exhibiting a high Suzuki grade (III-VI), and 59% demonstrated a mustache sign. If a mustache sign was present, this demonstrated a 94% positive predictive value for the presence of a high Suzuki grade and 77% positive predictive value for a Matsushima grade A/B outcome postoperatively.

Conclusions: As MMD severity correlated with the development of different forms of collateralization, a unique angiographic finding of a mustache sign is highlighted, which is seen in advanced MMD and indicates robust arterio-arterial collateralization with anticipated benefit from surgical revascularization.