NF1 and Moyamoya disease: FCA was also a significant etiology and FCA-I was identified in four patients, two of them with varicella virus infection, a condition with an established association with childhood AIS [6,10,11]. In Portugal, varicella virus vaccination is not included in the national vaccination program, and the incidence of vasculopathy related to this infection may become important to plan for healthcare resources. Moyamoya disease is also a significant cause of AIS and can be idiopathic (as in one of our patients) or associated with other conditions such as NF-1 (as in another of our patients).