Giant Extracranial Aneurysms of Both Internal Carotid Arteries with Aberrant Jugular Veins in a Patient with Neurofibromatosis Type 1

Abstract

SUMMARY:Although neurofibromatosis type 1 (NF-1) is commonly considered neurocutaneous, severe arterial and venous abnormalities have been noted. Our patient, a 28-year-old woman, had bilateral giant extracranial aneurysms of the internal carotid arteries as well as skull base meningoceles involving the jugular foramina and aberrant jugular veins. CT and MR imaging, as well as digital subtraction and/or other angiography techniques, may be required to clarify pathology in patients with suggested vascular lesions.T he autosomal dominant mutation underlying neurofibromatosis type 1 (NF-1) has a very high prevalence, affecting 1 in 3000 Americans.1,2 Although NF-1 is defined by neurocutaneous findings, severe abnormalities of bone, 1 arteries, 2,3 and veins 4 have been noted. We describe a 28-year-old patient with bilateral giant extracranial aneurysms of the internal carotid arteries (ICAs), skull base meningoceles involving the jugular foramina, and aberrant jugular veins, who was treated successfully: After obtaining detailed imaging studies, we sacrificed her left ICA and used intravascular trapping with MicroCoils (MicroCoil System; Micrus, San Jose, Calif) in the right ICA and an endoluminal stent graft in the right external carotid artery (ECA) to bridge the orifice of the right ICA and exclude internal carotid flow. We discuss the pathogenesis of this multisystem disease to emphasize the importance of using MR imaging and CT techniques to clarify the lesions present in patients with suggested vascular abnormalities. Case ReportA 28-year-old woman with skin hyperpigmentation, multiple softtissue masses bilaterally at the neck, and multiple café-au-lait spots on the trunk since 3 years of age was diagnosed with NF-1. Her bilateral neck plexiform neurofibromas had grown slowly and were accompanied by cervical neuralgia. Progressive dysarthria and dysphagia and minimal right hemiparesis had also developed. Two years previously, the patient had experienced a large left middle cerebral artery (MCA) infarction.At admission, 2 large masses with bruit were noted bilaterally at the upper neck. Neurologic examination revealed dysfunction of cranial nerves IX-XII, with symptoms including dysphagia, dysarthria, hoarseness, and weakness of the left trapezius muscle. In addition, tongue deviation to the left on protrusion and right lower extremity spasticity were noted; these were considered sequelae of the infarction.MR imaging confirmed the large left MCA infarct near the left lateral ventricle and revealed recent infarcts in the left cerebral hemisphere, a giant aneurysm of the left cervical ICA (4 ϫ 5 cm in the transverse plane, 8 cm long) with mural thrombus, and another infarct of the right cervical ICA (3 ϫ 4 cm in the transverse plane, 5 cm long) (Fig 1), as well as infiltrative plexiform neurofibromas in the neck extending between the muscles of the left shoulder. A short stenotic segment of the right extracranial ICA was observed above the aneurysm tip. CT angiography was performed when the patient developed tac...

Intracranial and Extracranial Fusiform Aneurysms in a Patient with Neurofibromatosis Type 1: A Case Report

“…Our patient showed only aneurysmal lesions without definite stenotic lesion. Ku et al (5) reported a case of 28-year-old woman, had bilateral giant extracranial aneurysms of the internal carotid arteries, which shows very similar manifestation of cerebral vasculopathy in NF-1 to our patient. In comparison with our case of relatively asymptomatic 17-year-old boy, the patient developed sudden-onset symptoms related to her vascular lesions followed by prompt coil embolization and graft stent placement of the affected arteries.…”

“…Recent research on the morbidity and mortality in NF-1 disclosed 2 factors independently associated with an excess of mortality in children and adults under 30 years of age, soft tissue malignancies and vascular disease (5). …”

“…The precise mechanism involved in cerebral vasculopathy in NF-1 is still not well understood but are likely related to the function of neurofibromin, the protein product of the NF-1 gene (2, 5, 6). Neurofibromin has been shown to control cell growth by positively regulating intracellular level of cAMP and negatively regulating Ras signaling pathway (6).…”

Internal Carotid Artery Aneurysms in a Patient With Neurofibromatosis Type 1

“…These include compression or infiltration of adjacent blood vessels by a neurofibroma, anomalous vessels within a neurofibroma, spindle cell proliferation, and proliferation of nerves within blood vessel walls. 1,4 In the case herein described, histologic examination revealed a neurofibroma adjacent to the carotid artery aneurysm, which likely represent soft tissue involvement rather than the primary cause of the aneurysm. One theory is that the vascular lesions may result from a decrease in the protein product of NF-1 gene, neurofibromin, which shares sequence with the ras oncogene, leading to excessive endothelial and smooth muscle cells proliferation, a process analogous to that which produces the cutaneous neurofibromas.…”

Increased Risk of Cerebrovascular Disease Among Patients With Neurofibromatosis Type 1

“…Several case reports describe the link between stroke in NF1 patients with moyamoya syndrome [20][21][22] and other cerebral arteriopathies. 6,12,14,[23][24][25] Also, at least 1 case report describes a hypertensive stroke in a child with NF1. 26 However, to the best of our knowledge, there have been no population-based studies that address the risk of cerebrovascular events requiring hospitalization among patients with NF1.…”