Prevalence and disease spectrum of fibromuscular dysplasia in patients with spontaneous cerebrovascular artery dissection

Objective: Spontaneous cervical artery dissection (sCeAD) is the most frequent cause of ischemic stroke in young adults and has been associated to various arteriopathies, such as fibromuscular dysplasia (FMD). The aim of this study was to assess the prevalence of both cervical and extra-cervical FMD in patients with a diagnosis of CeAD. Design and method: All patients discharged from the Stroke Unit of A.O.U. Città della Salute e della Scienza of Turin from 2016 to 2020 with a diagnosis of CeAD underwent a contrast-enhanced CTA from chest to pelvis to look for FMD-related lesions (multifocal stenosis, aneurysms, dissections, arterial tortuosity). FMD diagnosis was assessed in the presence of at least a multifocal stenosis in one of the vascular beds explored. Results: Among 56 patients with spontaneous CeAD, 72.7% were male of middle age (52±8.5 y.o.). According to radiological findings, 43.2% of patients showed extra-cervical arterial lesions, with a prevalence of overall FMD (defined as the presence of at least a multifocal stenosis) reaching 47.3% of the studied sample and affecting carotid (36.4%), renal (18.9%), visceral (16.2%), iliac (22.2%) and coronary arteries (2.7%) respectively. Renal involvement included multifocal renal stenosis (13.5%) and arterial aneurysms (5.4%). Visceral involvement included multifocal stenosis (13.5%), visceral aneurysms (2.7%) and silent mesenteric artery dissection (5.4%). Iliac involvement included multifocal stenosis (2.7%), silent artery dissection (2.7%) and tortuosity (16.7%). Furthermore, two spontaneous dissections, one of the left external iliac artery and the other of the coeliac trunk, clinically asymptomatic, were reported in two males with no multifocal stenosis. Two women suffered also from SCAD. Multivascular extra-cervical involvement was observed in almost one third of the patients (27.0%) with sever lesions (multifocal high degree stenosis and/or arterial dissections) affecting 13.5% of the population. Conclusions: According to our results, we demonstrated that FMD is frequently associated to CeAD and that silent FMD-related lesions, even severe as arterial dissections, may coexist in such patients. Therefore, FMD should always be taken in consideration in the differential diagnosis of spontaneous arterial dissection, especially in young subjects without major cardiovascular risk factors.