Evidence for progressive neurodegeneration in iatrogenic cerebral amyloid angiopathy

INTRODUCTION: Iatrogenic transmission of amyloid beta can cause cerebral amyloid angiopathy (CAA) and Alzheimer's disease (AD), but the relationship between these phenotypes is unclear. METHODS: We retrospectively analyzed standardized neuropsychological and neuroimaging data from 11 patients with iatrogenic CAA (iCAA). Brain MRI was assessed for medial temporal lobe atrophy (MTA), the posterior atrophy score for parietal atrophy, and global cortical atrophy (GCA). RESULTS: All patients (mean age 42 ± 8.3 years) had childhood neurosurgery; 91% had confirmed cadaveric dura exposure. Six patients (55%) presented with intracerebral hemorrhage, and none showed MTA, parietal atrophy, or GCA at presentation. Over a median 5-year follow-up, 8/11 (73%) developed atrophy on at least one score, moderate to severe in three patients. Cognitive impairment was present in 9/11 (82%) at a median 3-year follow-up. AD was confirmed histopathologically in 2/4 (50%) examined cases. DISCUSSION: Progressive brain atrophy and cognitive impairment are common in iCAA, suggesting frequent co-existing neurodegeneration and possible AD pathology. Vigilance for cognitive decline may enable earlier identification and management.