Introduction Bilateral chronic internal carotid artery (ICA) occlusion in young adults is rare and poses unique diagnostic and management challenges. while moyamoya is a common suspicion in bilateral stenosis in the young, other pathologies such as fibromuscular dysplasia, vasculitis, dissection, post‐radiation changes, atypical atherosclerosis should be considered. The Circle of Willis often serves as a vital compensatory network, sustaining cerebral viability when primary inflow is compromised. Digital subtraction angiography (DSA) remains the gold standard for mapping these complex collateral pathways, while functional imaging defines their physiological limits. Together, they inform revascularization decisions. Purpose To present a case of bilateral ICA occlusion and its diagnostic consideration and management consideration. Materials and Method Case was encounter in routine clinical encounter. Result A 34‐year‐old female with type 1 Diabetes Mellitus and a History of Deep vein thrombosis and pulmonary embolism presented with two weeks of right‐sided numbness and global headache. MRI remarked for acute ischemic stroke on left watershed MCA and PCA territory with left parietal hemorrhage. CT angiography revealed bilateral ICA occlusion shortly after their origin with Para clinoid reconstitution on left. Digital Subtraction Angiography remarkable for bilateral chronic internal carotid artery occlusions, from cervical origin to the intracranial segment onto the carotid terminus on the right and minimal antegrade flow to the proximal cavernous segment on the left with retrograde collateral filling from the left ophthalmic artery and branches of the middle meningeal artery to the intracranial middle cerebral artery branches. There was minimal retrograde filling of the right internal carotid artery terminus, atypical for moyamoya appearance without significant lenticular striatal neovascular genesis. Diamox Perfusion imaging showed Preserved cerebrovascular reserve (CVR) in most territories except the left MCA vertex region, which showed paradoxical flow reduction (CVR 55%), consistent with exhausted autoregulation in an area of prior infarction. Conclusion In young patients with chronic bilateral ICA occlusion, the Circle of Willis may sustain life‐sustaining perfusion but cannot always protect all territories. DSA precisely defines the structural collateral network, while Diamox perfusion identifies regions at highest hemodynamic risk. This integrated approach provides essential guidance for management, including consideration of extra cranial‐intracranial bypass surgery. This case underscores the importance of pattern recognition and the nuanced interpretation of collateral circulation in decision‐making. image
Baniya et al. (Sat,) studied this question.