Anti-neutrophil Cytoplasmic Antibody-Associated Vasculitis Complicated by Subarachnoid Hemorrhage due to a Ruptured Cerebral Aneurysm: A Case Report

Anti-neutrophil cytoplasmic antibody-associated vasculitis is an autoimmune disorder characterized by inflammation of small vessels, with potential for multi-organ involvement. Anti-neutrophil cytoplasmic antibody-associated vasculitis can affect blood vessels throughout the body, but involvement of cerebral vessels is relatively rare. We report a case of anti-neutrophil cytoplasmic antibody-associated vasculitis complicated by a subarachnoid hemorrhage due to the rupture of a cerebral artery pseudoaneurysm, which was successfully managed with endovascular intervention. A 61-year-old man presented with headache, purpura on the extremities, profound fatigue, and diffuse myalgia. Computed tomography revealed subarachnoid hemorrhage. Based on clinical, laboratory, brain magnetic resonance imaging, and cerebral angiography findings, the patient was diagnosed with anti-neutrophil cytoplasmic antibody-associated vasculitis and subarachnoid hemorrhage secondary to the rupture of pseudoaneurysm formed in perforating branch arising from the vertebral artery. Parent artery occlusion of the vertebral artery resulted in the complete obliteration of the aneurysm and no rebleeding occurred during the course. Despite intensive care management, the patient developed renal and putaminal hemorrhages, resulting in a fatal outcome. Anti-neutrophil cytoplasmic antibody-associated vasculitis may involve the cerebral vessels, and in cases complicated by ruptured aneurysms, implementing appropriate re-rupture prevention alongside adequate treatment of anti-neutrophil cytoplasmic antibody-associated vasculitis may help improve clinical outcomes.