Current Overview of Clinical and Radiological Findings Associated With Cerebral Amyloid Angiopathy

Cerebral amyloid angipopathy (CAA), the second most common cause of spontaneous acute intracerebral hemorrhage after hypertension in the elderly population is characterized by brain parenchymal damage secondary to hemorrhage and ischemia caused by the accumulation of Aβ protein in the walls of small arteries and arterioles. Advanced age is the most significant risk factor for CAA. While the definitive diagnosis requires histopathological examination through autopsy/biopsy, the probable or possible diagnosis of CAA is based on clinical features as well as characteristic neuroimaging findings. With the increasing elderly population and the growing prevalence of succesibility-weighted magnetic resonance imaging sequences in routine, it becomes imperative to have a thorough understanding of the imaging spectrum associated with CAA. Early diagnosis is extremely critical in patients with CAA who have not yet developed intracranial hemorrhage. Furthermore, patients with CAA may present clinically transient focal neurological episodes or cognitive impairment, which can be mistaken for transient ischemic attacks caused by convexity subarachnoid hemorrhage. Additionally, before initiating newly introduced anti-amyloid monoclonal antibody drugs in Alzheimer's disease, it is necessary to exclude signs of CAA. Moreover, the anticipated side effects of these drugs often manifest imaging abnormalities resembling inflammation or bleeding associated with CAA, necessitating familiarity with the imaging findings of CAA. In this review, the pathophysiology, clinical manifestations, and radiological findings of sporadic CAA will be detailed.