Meningovascular Inflammation in Cerebral Amyloid Angiopathy‐Related Cortical Superficial Siderosis

The role of inflammation in cortical superficial siderosis (cSS), a marker of cerebral amyloid angiopathy (CAA) linked to high hemorrhage risk, is unclear. We examined 15 patients with cSS using 3 T post-contrast vessel wall MRI (VWI) and CSF analysis. Although only 27% met current CAA-ri criteria, 93% showed vessel wall enhancement or sulcal hyperintensities near cSS, frequently extending beyond. Seven patients with follow-up VWI demonstrated corticosteroid-responsive regression of inflammation. CSF albumin quotients, indicating blood-brain barrier dysfunction, correlated with MRI inflammation scores. These findings reveal subclinical meningovascular inflammation in cSS and support VWI for detecting a broader CAA-related inflammation spectrum.