Cerebral amyloid angiopathy without and with cerebral hemorrhages: A comparative histological study

TLDR

The study aimed to identify factors associated with cerebral hemorrhage in brains with cerebral amyloid angiopathy (CAA). Researchers performed a comparative postmortem histopathological analysis of amyloid‑containing vessels in 136 brains without hemorrhage (elderly general hospital patients and neuropsychiatric disorder patients) and 17 brains with both CAA and hemorrhage. CAA was present in 45% of the elderly group and 54% of the neuropsychiatric group, but was more severe in the hemorrhage group, where fibrinoid necrosis and microaneurysms were observed only in brains with hemorrhage, indicating that severe CAA and fibrinoid necrosis are the key predictors of hemorrhage.

Abstract

Abstract To identify those factors associated with cerebral hemorrhage among brains with cerebral amyloid angiopathy (CAA), we undertook a comparative postmortem histopathological study of amyloid‐containing vessels in the brains of patients with and without hemorrhage. Those without hemorrhage were represented by the following two groups: (1) elderly patients from a large general hospital (n = 66; age range, 75–107 years) and (2) patients with various neuropsychiatric disorders (n = 70; age range, 27–96 years). CAA was found in 45% of thefirst group and in 54% of the second group. The findings in these patients were compared with those in 17 brains in which both CAA and cerebral hemorrhage were present. We found that CAA was more severe in the brains with cerebral hemorrhage than in those without, and that fibrinoid necrosis was seen only in the brains with cerebral hemorrhage (12 of the 17 brains). Microaneurysms occurred only in the presence of severe, rather than moderate or mild, CAA. Serial sections in 2 brains of patients with cerebral hemorrhage showed fibrinoid necrosis, microaneurysms, and vascular rupture in close association with the hemorrhage. In 2 patients, hemorrhage was precipitated by trauma, and in 1, it was secondary to metastatic carcinoma. The features of brains from patients with CAA that are most consistently related to cerebral hemorrhage are (1) a severe degree of CAA and (2) the presence of fibrinoid necrosis, with or without microaneurysms.