Neurofibromatosis type 1 associated with moyamoya syndrome in children.

Vascular abnormalities in neurofibromatosis type 1 may arise anywhere in the cardiovascular system, and cerebrovascular involvement is the predominant feature of moyamoya syndrome. Because neurofibromatosis type 1 is a neurocutaneous disorder and routine follow-up with cranial MRI is not standard practice in asymptomatic children, accurate epidemiologic data are lacking. On follow-up, clinical and radiologic progression is often found in patients with moyamoya syndrome.We performed a retrospective analysis on children with neurofibromatosis type 1 who had been diagnosed with moyamoya syndrome on cranial MRI.Of the 197 children diagnosed with neurofibromatosis type 1, 168 had undergone a cranial MRI, and four (2.3%) of them had moyamoya syndrome. At diagnosis, one child had headache and vomiting related to a right frontal hematoma and the other three children were asymptomatic, including one child with a previous history of renal arteriopathy. In two children moyamoya syndrome was unilateral.The association between moyamoya syndrome and neurofibromatosis type 1 is rare, but it poses a potential risk of clinicoradiologic progression. Targeted monitoring of children with neurofibromatosis type 1 ensures an early diagnosis of moyamoya syndrome.