cerebral amyloid microangiopathy (Alzheimer type)

Etiology: 1) Alzheimer's disease 2) Down's syndrome 3) normal aging Pathology: 1) amyloid deposition in: a) leptomeninges (arachnoid & pia) -> amyloid within leptomeningeal vessels stops abruptly as vessels enter subcortical white matter b) arterioles, venules & capillaries of cerebral cortex 1] variable for any given burden of amyloid plaque 2] may occur the brains of elderly patients in the absence of AD or neuritic plaques c) rarely do vessels within white matter contain amyloid 2) ultrastructural pathology a) amyloid fibrils in abluminal basement membrane of vessels b) spillover of fibrils into perivascular neuropil (dyshorric angiopathy 3) hyaline necrosis surrounding amyloid deposits in vessel wall -> microvascular hemorrhages may occur) c) amyloid fibrils consist principally of A4/40

Related

A4 amyloid peptide; beta-peptide Alzheimer's disease (AD) amyloid (senile, neuritic) plaque

References

- Selkoe DJ. Alzheimer's disease: genes, proteins, and therapy. Physiol Rev. 2001 Apr;81(2):741-66. Review. PMID: 11274343