The Inflammatory Form of Cerebral Amyloid Angiopathy or “Cerebral Amyloid Angiopathy-Related Inflammation” (CAARI)

Cerebral amyloid angiopathy-related inflammation (CAARI) is a recently recognized syndrome of reversible encephalopathy seen in a subset of patients with cerebral amyloid angiopathy (CAA). CAA is a disorder of the elderly in which amyloid peptides are deposited in the walls of cerebral arteries, leading to microhemorrhages, macrohemorrhages, and eventually dementia. In a few cases, the amyloid deposition is accompanied by inflammation or edema. The clinical syndrome of CAARI is distinguished by subacute neurobehavioral symptoms, headaches, seizures, and stroke-like signs, contrasting the acute intracranial hemorrhage typically seen in CAA. Magnetic resonance imaging findings may be symmetric or asymmetric and involve patchy or confluent T2 hyperintense lesions in the cortex and subcortical white matter. Recent diagnostic criteria have been proposed which help distinguish CAARI from alternative diagnoses. Improvement has been reported in most cases with immunosuppression, although a few cases have had recurrent symptoms. Here, we review the clinical and radiologic features of CAARI and compare these with CAA.