Amyloid beta-related angiitis (ABRA) is a rare and extreme form of cerebral amyloid angiopathy (CAA) in which the deposition of amyloid beta in cerebrovascular vessels results in a transmural, granulomatous inflammatory vasculitis. Reported presentations include seizures, hallucinations, leukoencephalopathy, and neurologic deficits. Here, we present a novel case of ABRA characterized by intracerebral cortical hematoma with associated microhemorrhages in the absence of severe cognitive or neurologic deficits.

A 76-year-old female with history of hypertension, diabetes mellitus, hypothyroidism, and rheumatoid arthritis (on infliximab and methotrexate) presented with acute-onset headache, mild speech difficulties, difficulty grasping objects, and gait instability. CTH/CTA was notable for left temporo-occipital intraparenchymal hematoma with surrounding vasogenic edema. MRI Brain confirmed stable hematoma, subtle leptomeningeal enhancement, and left predominant microhemorrhages with hemosiderin deposits concerning for inflammatory CAA. Digital subtraction angiography showed no evidence of vasculitis or vascular malformations. CT chest, abdomen, and pelvis with contrast revealed no underlying malignancy. Rheumatology was consulted to evaluate for rheumatoid arthritis or drug-related inflammatory CAA, but alternative etiologies were excluded.

She underwent posterior left temporal craniotomy for open biopsy of dura, brain, and intraparenchymal hemorrhage with clot evacuation. Left brain biopsy returned with evidence of severe CAA-related inflammation and ABRA.

A five-day course of 1000mg methylprednisone was completed followed by a prednisone taper. At 3-week follow up, she reported improving headache and resolution of neurologic deficits. 

Although asymmetric distribution of microbleeds and edema are recognized in ABRA and other inflammatory CAA subtypes, the marked lateralization observed is unusual and raises the possibility of venous congestion, not typically associated with ABRA. This case broadens the spectrum of recognized presentations, highlights the complexity of diagnosis in considering ABRA for atypical hemorrhagic or inflammatory patterns. Early recognition and initiation of immunosuppressive therapy remain critical for optimizing outcomes.