Investigators at the Alberta Children’s Hospital Research Institute, University of Calgary; the Hospital for Sick Children, Toronto, and other centers in Canada screened Canadian pediatric stroke registries and the literature and found 81 cases (15 new, 66 from the literature) of pediatric stroke associated with fibromuscular dysplasia or renal arteriopathy. Twenty-seven patients had pathologically proven fibromuscular dysplasia, with predominant intimal fibroplasia in 89%; none had typical adult medial fibroplasia. Stroke was ischemic in 63% and hemorrhagic in 37%; multifocal in 40%. Onset was early and <12 months in 33%. Angiography showed a focal, stenotic arteriopathy in 78% and “string of beads” in 22%. Renal arteriopathy (63%) with hypertension (92%) was common, with systemic arteriopathy in 72%, and moya-moya in 35%. Therapies were anti-inflammatory in 29% and anti-thrombotic in 27%, and outcomes were poor in 63%, with stroke recurrence in 36%. Patients with clinically suspected fibromuscular dysplasias (n=31) were older, normotensive, and with string-of-breads angiography and good outcome. [1]

COMMENT. Fibromuscular dysplasias (FMDs) are a group of idiopathic, non-inflammatory arteriopathies with medial fibroplasia, typically affecting young adult females, with renal and cerebral vessel involvement, “string-of-beads” angiography, hypertension, and stroke [2]. Three main categories of FMD are classified as medial, intimal, and perimedial fibroplasia, based on the site of disease in the arterial wall. Most pathologically proven cases of FMD reported in children do not have medial fibroplasia and the characteristic “string-of-beads” sign on angiography, and intimal fibroplasia predominates. Arterial imaging, craniocervical and systemic, should be considered in pediatric stroke when fibromuscular dysplasia is suspected. In a case-report of a 12-year-old boy with ischemic stroke caused by intracranial fibromuscular dysplasia, preliminary imaging investigations included CT and MR angiography, but a definitive diagnosis was reached following a conventional cerebral angiogram. [3]