Iatrogenic cerebral amyloid angiopathy: two new cases and systematic review of case reports with neuropathological data.

Awareness concerning iatrogenic cerebral amyloid angiopathy (iCAA) is increasing but its pathophysiology remains unclear. We discuss the implications of the clinical, imaging and neuropathological findings in two previously unpublished cases of probable iCAA: a 55-year-old female presenting with rapidly progressive cognitive impairment, showing imaging and histological evidence of CAA and having undergone neurosurgical treatment at the age of 6; and a 56-year-old male with a four-year history of recurring intracerebral hemorrhages (ICH) and neurosurgical intervention at the age of 5. In the first case, a brain biopsy was performed.Additionally, a systematic review of iCAA cases with neuropathological data suggests that most of the patients have concomitant amyloid parenchymal deposition and none or minimal tau pathology. The pathophysiological role of tau pathology in iCAA remains unclear. iCAA patients presenting with cognitive impairment without symptomatic ICH may be underdiagnosed.