Cerebral amyloid angiopathies

Pathology findings: Cerebral amyloid angiopathies are defined by the presen ce of amyloid deposits on the wails of cerebral vessels. These amyloid depo sits are found in the media of arterioles of the leptomeninges and the cort ex. They are sometimes associated with Alzheimer-type lesions. Overt amyloi d vasculopathy characterized by lesions of the vascular wall with a media t otally replaced by amyloid substance may be observed. Clinical expression: Lobular hemorrhage, often with recurrent episodes is t he most frequent manifestation of cerebral amyloid angiopathy. Cerebral inf arcts or leukoencephalopathy may also be observed. An association with cere bral angeitis has been reported in a few cases. Sporadic or familial disease: Several types can be distinguished depending on the sporadic or familiar nature of the disease pattern as well as the ch emical make-up of the protein deposit. In sporadic cerebral amyloid angiopa thy the deposit is composed of protein A beta, and in familial cases, of pr otein A beta, cystatine C, gelsosine or transthyretine. Mutation of the gen es coding for amyloid substance constituents have been identified in divers e forms of familial cerebral amyloid angiopathy. (C) 2000, Masson, Paris.