# Probable cerebral amyloid angiopathy - related inflammation in a 32-year-old woman with down syndrome

## TL;DR

A 32-year-old woman with Down syndrome developed cerebral amyloid angiopathy-related inflammation, showing that this rare condition can cause sudden neurological decline.

## Contribution

This case report highlights CAA-RI as a potential cause of acute neurological decline in young individuals with Down syndrome.

## Key findings

- MRI showed asymmetric T2/FLAIR hyperintensities and leptomeningeal enhancement in a young DS patient.
- Corticosteroids and rituximab were used to treat persistent symptoms of CAA-RI in a patient with Down syndrome.
- CSF analysis revealed significant inflammation in the patient with no microbleeds detected.

## Abstract

Inflammatory cerebral amyloid angiopathy (CAA-RI) is a variant of CAA, rarely seen in young individuals with Down syndrome (DS). We describe a 32-year-old female with DS who developed a systemic inflammatory state followed by acute neurological symptoms, including seizures and hemiparesis. Brain MRI disclosed asymmetric T2/FLAIR hyperintensities with leptomeningeal enhancement and focal superficial siderosis on susceptibility-weighted imaging, without microbleeds; cerebrospinal fluid showed marked inflammation. After partial improvement with corticosteroids, rituximab was started due to persistent symptoms. This case highlights CAA-RI as a cause of acute decline in DS and supports the use of rituximab in refractory cases.