Atypical Arteritis in Internal Carotid Arteries: A Novel Concept of Isolated Internal Carotid Arteritis.

We presented a 38-year-old woman suffering from acute cerebral infarction due to arteritis limited to bilateral internal carotid arteries without a condition of giant cell arteritis or granulomatosis with polyangitis. Our case is unprecedented and characterized by a young woman with wall enhancement in the internal carotid arteries on contrast-enhanced magnetic resonance imaging (MRI), therapeutic effects of steroids, and positive status for human leucocyte antigen-B39, -B51 and -DR4. These disease characteristics were not in accordance with existing diagnostic criteria of vasculitis, such as Takayasu's arteritis, giant cell arteritis, granulomatosis with polyangiitis, and Behcet's disease. We suggested consideration of a novel "isolated internal carotid arteritis" disease concept.