• Amyloid
• cerebrovascular disease

Serendipitously, two unrelated case reports in Practical Neurology illustrate the spectrum of inflammatory amyloid cerebrovasculopathies.1 2 Amyloid in the brain—wrong type, place or quantity—spells trouble. Plaques of amyloid between neurones help to generate Alzheimer’s disease, far and away the most common manifestation. Less frequently but often no less severely, amyloid in blood vessels causes cerebrovascular mischief. There are three recognised histopathological patterns, and three related but likely distinct amyloid cerebrovasculopathies distinguished by the presence and distribution of inflammatory change, with variably overlapping clinical phenotypes.

The first of these to be recognised—during the 1970s—was cerebral amyloid angiopathy (CAA),3 4 with little or no inflammation at all. Here, amyloid Aβ40 is deposited in the media and adventitia particularly of small meningeal and cortical vessels. Multiple TIA-like episodes occur—‘amyloid spells’—some (curiously) with migraine-like features5; progressive dementia, and lobar haemorrhage may also occur. CAA encompasses a …