The goal of this retrospective case review was to review cases of Cerebral Amyloid Angiopathy Related Inflammation (CAARI) to identify clinical patterns, radiographic features and response to treatment. We will also seek to clarify the diagnostic approach.

CAARI is an uncommon complication of cerebral amyloid angiopathy (CAA) that manifests with a subacute onset of various neurologic symptoms including: neuropsychiatric changes, cognitive decline, seizure, and focal deficits.  There is significant variability in the literature in both terminology and diagnostic criteria that can make it difficult for proper identification and management.

Patients treated at Vanderbilt University Medical Center (VUMC) with clinical and radiographic features consistent with probable CAA who developed subacute neurologic deficits meeting criteria for CAARI were identified.  Clinical history and presentation, radiologic features and available serologic, ApoE genetic testing, and cerebrospinal fluid including ADmark testing were reviewed.

A total of 8 patients with definite or probable CAARI were identified with chart review.  Three patients had a preceding infectious or immunologic challenge including one patient who was receiving allergy desensitization shots. A key imaging feature of interest was the clustering of cerebral microhemorrhages in regions of cerebral edema – this finding appears to be distinctive for CAARI and was seen in all 8 of our patients. Three patients died in the setting of the disease, the rest responded well to immunotherapy.

Two clinical patterns of interest were observed: (1) A post-infectious or post-immunologic challenge pattern was observed in a substantial portion of the patients. (2) Imaging revealed clustering of microhemorrhages in the areas of edema/inflammation. This latter observation may be particularly helpful in distinguishing CAARI from other disease with diffuse T2 and FLAIR signal changes such as tumor or infection and would be a useful addition to current diagnostic criteria.