Cerebral amyloid angiopathy related inflammation: An under recognized but treatable complication of cerebral amyloid angiopathy

Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a subset of cerebral amyloid angiopathy (CAA) causing a reversible encephalopathy characterized by seizures and focal neurological deficit. Previously, biopsy was required to make this diagnosis, distinct radiological features have allowed development for clinicoradiological criteria to assist in diagnosis. CAA-ri is an important condition to recognize as patients respond to high dose corticosteroids with significant resolution of symptoms. A 79-year-old woman presents with new onset seizures and delirium with prior history of mild cognitive impairment. An initial computed tomography (CT) brain demonstrated vasogenic oedema in the right temporal lobe, and magnetic resonance imaging (MRI) showed bilateral subcortical white matter change and multiple microhemorrhages. The MRI findings were suggestive of cerebral amyloid angiopathy. Cerebrospinal fluid analysis demonstrated raised protein and oligoclonal bands. A thorough septic and autoimmune screen demonstrated no abnormality. Following a multidisciplinary discussion, a diagnosis of CAA-ri was made. She was commenced on dexamethasone and her delirium improved. CAA-ri is an important diagnostic consideration in an elderly patient who presents with new seizures. Clinicoradiological criteria are useful diagnostic tools and may avoid the need for invasive histopathological diagnosis.