Rapidly Progressive Intracranial Arterial Stenosis in Giant Cell Arteritis: A Case Report with Longitudinal Imaging and Implications for Endovascular Management.

Objective: The natural history of intracranial arterial stenosis caused by giant cell arteritis (GCA) and the effects of therapeutic interventions remain unclear. We report a case of rapidly progressive intracranial arterial stenosis associated with GCA and discuss its clinical course and the implications for endovascular management. Case Presentation: A 75-year-old man developed multiple intracranial arterial stenoses and occlusions over several months, resulting in cerebral infarction. Percutaneous transluminal angioplasty was performed for severe stenosis of the cavernous segment of the right internal carotid artery, which exhibited delayed distal contrast opacification. Temporal artery biopsy confirmed the diagnosis of GCA. Although inflammatory markers improved with optimal medical treatment, the untreated intracranial arterial stenoses progressed rapidly, leading to extensive cerebral infarction. In contrast, no restenosis was observed at the site treated with angioplasty during the 6-month follow-up period. Conclusion: Rapidly progressive intracranial involvement in GCA may lead to a devastating clinical course, with progression of arterial stenosis occurring despite apparent control of systemic inflammation. This case highlights that intracranial arterial stenosis due to GCA can progress rapidly even under immunosuppressive therapy, underscoring the importance of serial vascular imaging and suggesting that some patients may benefit from early consideration of endovascular treatment.