Cerebral Amyloid Angiopathy-Related Inflammation (CAA-ri) Masquerading as PRES
Taleen Shahrigian1, Jason Schick1, Lauren Turner1, Christopher Gilbert2, Muhammad Farooq1, Aileen Antonio1
1Hauenstein Neurosciences, Trinity Health Grand Rapids, 2Trinity Health Grand Rapids
Objective:
To present a case of cerebral amyloid angiopathy-related inflammation mimicking posterior reversible encephalopathy syndrome, highlighting the diagnostic challenge and importance of early recognition.
Background:
Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a distinct inflammatory subtype of cerebral amyloid angiopathy (CAA), characterized by an immune response targeting vascular beta-amyloid deposits. Clinically, CAA-ri may present with encephalopathy, headache, or seizures, and radiologically with asymmetric white matter changes and microhemorrhages. These features often overlap with Posterior Reversible Encephalopathy Syndrome (PRES), a condition marked by acute neurological symptoms and vasogenic edema, typically in the posterior brain regions and commonly associated with hypertension. This overlap poses a diagnostic challenge, as the management of these conditions differs significantly. PRES generally improves with correction of underlying triggers, while CAA-ri requires prompt immunosuppressive therapy. Delayed recognition of CAA-ri can lead to poor outcomes, underscoring the importance of early and accurate diagnosis.
Results:
A 75-year-old woman with hypertension, hyperlipidemia, and biopsy-proven CAA presented with acute encephalopathy. Head CT revealed bilateral parieto-occipital vasogenic edema, suggestive of PRES. Despite antihypertensive management, her mental status failed to improve.
Brain MRI showed diffuse, non-enhancing white matter hyperintensities, without diffusion restriction, and hemosiderin deposition – raising concern for CAA-ri. High-dose intravenous methylprednisolone and plasma exchange were initiated, but she showed no clinical improvement.
Due to refractory encephalopathy and progressive neurotoxicity, her family transitioned her to hospice care.
Conclusions:
This case highlights the diagnostic overlap between PRES and CAA-ri and the importance of distinguishing between them. CAA-ri should be considered in PRES-like presentations, especially in normotensive patients or those with posterior-predominant edema, cognitive decline, or a history of CAA. A non-responsive or atypical course following PRES management should prompt further evaluation. Early immunosuppressive therapy is essential, though outcomes may be poor in advanced disease.
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