A pediatric case of transient ischemic attacks associated with a hypoplastic internal carotid artery and neurofibromatosis type 1

Neurofibromatosis type 1 (NF1; OMIM 162200 ) is associated with various cardiovascular abnormalities, including moyamoya syndrome, which often leads to cerebral ischemia. However, symptomatic internal carotid artery (ICA) hypoplasia necessitating revascularization surgery has not been previously reported in patients with NF1. Here, we present a pediatric NF1 case involving symptomatic unilateral ICA hypoplasia associated with transient ischemic attacks. Based on the presence of multiple café-au-lait spots and subcutaneous neurofibromas, a three-year-old girl, who presented at our hospital complaining of repeated episodes of transient right hemiparesis, was diagnosed with NF1. Head magnetic resonance imaging revealed an “ivy sign” in the left hemisphere on T2-fluid attenuated inversion recovery images. Cerebral angiography and magnetic resonance angiography revealed a left common carotid artery narrowing from its origin and a left ICA occlusion distal to the ophthalmic artery bifurcation. However, moyamoya vessels were not detected. Computed tomography scanning revealed a narrow left carotid canal, suggesting ICA hypoplasia. Cerebral perfusion imaging showed insufficient cerebral blood flow in the left middle cerebral artery territory. Therefore, the patient was diagnosed with symptomatic ICA hypoplasia associated with transient ischemic attacks, and revascularization surgery was performed. ICA hypoplasia, a congenital ICA narrowing, is typically asymptomatic. This case indicates that vascular smooth muscle proliferation associated with NF1 may have contributed to symptomatic ICA occlusion and that in patients with NF1 and ICA hypoplasia, careful long-term observation may be required.