Presentation
Expressive dysphasia and visual disturbance.
Patient Data
Confluent areas of sub-cortical and deep white matter high T2 signal within the left frontal, parietal and temporal lobes. Mild positive mass effect in the left frontal lobe. Punctate foci of restricted diffusion in left frontal and parietal lobes. Superficial siderosis of both cerebral hemispheres and multiple intraparenchymal sub-cortical microhemorrhages.
Case Discussion
This case highlights several imaging features of cerebral amyloid angiopathy, namely micro-hemorrhages, superficial siderosis, infarcts and amyloid related inflammation.
Imaging features of cerebral amyloid angiopathy or 'amyloid related imaging abnormalities' (ARIA) have been loosely divided into 2 groups, ARIA-H (hemorrhage) and ARIA-E (edema/edema).
Amyloid related hemorrhage (ARIA-H) has several manifestations:
- micro-hemorrhages, typically sub-cortical in distribution, correlating with disease progression and cognitive impairment
- lobar hematoma, in the same distribution as micro-hemorrhages
- sub-arachnoid hemorrhage, typically at the vertex and often associated clinically with seizures and/or TIA like symptoms
- superfical siderosis, the result of sub-arachnoid hemorrhage, frequently at cerebral vertex, rarely in the posterior fossa
Amyloid related inflammation with edema (ARIA-E):
- is a form of vasculitis
- may be associated with headache, cognitive decline and seizures
- manifests on imaging as confluent white matter T2 signal change, possibly involving cortex and with mass effect
- is potentially treatable - may respond to immunosuppression
Infarcts in patients with cerebral amyloid angiopathy are increasingly recognized as a manifestation of the disease. They probably reflect occlusive arteriopathy, and may be clinically silent.