THE DEVELOPMENT OF CEREBRAL AMYLOID ANGIOPATHY IN CEREBRAL VESSELS . A REVIEW WITH ILLUSTRATIONS BASED UPON OWN INVESTIGATED POST MORTEM CASES

The process of β-amyloid accumulation in cerebral vessels is presented. Cerebral amy loid angiopathy (CAA) was confirmed during an autopsy. It was diagnosed accord ing to the Boston criteria. Cerebral amyloid angiopathy can involve all kinds of cere bral vessels (cortical and leptomeningeal arterioles, capillaries and veins). The development of CAA is a progressive process. β-amyloid appears first in the tunica media, surrounding smooth muscle cells, and in the adventitia. β-amyloid is pro gressively accumulated, causing a gradual loss of smooth muscle cells in the vessel wall and finally replacing them. Then, the detachment and delamination of the out er part of the tunica media results in the “double barrel” appearance, fibrinoid necro sis, and microaneurysm formation. Microbleeding with perivascular deposition of ery throcytes and blood breakdown products can also occur. β-amyloid can also be deposited in the surrounding of the affected vessels of the brain parenchyma, known as “dys phoric CAA”. Ultrastructurally, when deposits of amyloid fibers were localized in or outside the arteriolar wall, the degenerating vascular smooth muscle cells were ob served. In the Institute of Psychiatry and Neurology the study was carried out in a group of 48 patients who died due to intracerebral hemorrhage caused by sporadic CAA.