This case highlights several imaging features of cerebral amyloid angiopathy, namely micro-haemorrhages, 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 (haemorrhage) and ARIA-E (edema/oedema).
Amyloid related haemorrhage (ARIA-H) has several manifestations:
- micro-haemorrhages, typically sub-cortical in distribution, correlating with disease progression and cognitive impairment
- lobar haematoma, in the same distribution as micro-haemorrhages
- sub-arachnoid haemorrhage, typically at the vertex and often associated clinically with seizures and/or TIA like symptoms
- superfical siderosis, the result of sub-arachnoid haemorrhage, frequently at cerebral vertex, rarely in the posterior fossa
Amyloid related inflammation with oedema (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 recognised as a manifestation of the disease. They probably reflect occlusive arteriopathy, and may be clinically silent.