Moyamoya Syndrome as a rare vasculopathy of the Central Nervous System in children with Neurofibromatosis Type 1

Introduction: Neurofibromatosis 1(NF1) is a multisystem disease affecting the skin, the central nervous system and the bones. Vasculopathy, within NF1, is a significant but insufficiently recognized complication of the disease. The prevalence of Moyamoya syndrome(MMS) in patients with NF1 is estimated at 0.6%. MMS is linked to genetic factors: an abnormality was found on chromosome 17q25.2 close to the gene responsible for NF1(17q11.2). Case Presentation: We present two young girls. One was born as a twin who in infancy had multiple cafe-au- lait spots without other signs of NF1. At the age of 18 months right-sided hemiparesis was noticed. MRI of the brain showed bilateral optic nerve glioma, treated by chemotherapy. At the age of 5.5 years follow-up neuroradiology led to suspicion of MMS. Digital subtraction angiography (DSA) showed left-side occlusion of the middle cerebral artery (MCA), with many collaterals. The other girl was admitted to hospital at the age of 3.5 years for lethargy, dysarthria and ataxia, with suspected intoxication. In the hospital left- side transitory hemi-insufficiency was found. Physical examination revealed many cafe-au-lait spots and inguinal freckling. Given the positive family history, the criteria were met for NF1.TCCD showed pathological cerebral circulation in the area of the left MCA and anterior (ACA). Magnetic angiography showed left pial angiomatosis, and a hypoplastic spheroidal and opercular segment of the left MCA, with many collaterals. DSA showed bilateral stenosis of the internal carotid artery. After a PET-CT Diamox test in both, Encephaloduroarteriosynangiosis resulted in recovery without additional symptoms or stroke. Conclusion: Vasculopathy in NF1 is a potentially serious and under-appreciated complication. MRA screening and assessment of cerebral circulation by Doppler could help in the early detection of vascular lesions in asymptomatic patients with NF1.