Amyloid β-related angiitis of the central nervous system: Report of 3 cases

Objective: Amyloid-β (Aβ) related angiitis (ABRA) is a recently described clinicopathological entity characterized by cerebrovascular Aβ deposition and arteritis. Cerebral Aβ deposition is commonly present in cerebal amyloid angiopathy (CAA) and Alzheimer's disease (AD) but is rarely associated with inflammatory infiltration of vessel walls. Our objective is to help clarify the clinical spectrum, radiographic findings, response to treatment, and outcomes of ABRA. The neuropathological relationship between ABRA, cerebral amyloid angiopathy, and Alzheimer's disease is discussed. Methods: We present three cases of ABRA managed at a tertiary care centre. Results: All three patients presented with seizures and cognitive dysfunction; one had multifocal neurologic findings. Brain biopsies revealed inflammatory arteritis with Aβ deposits in the vessel walls. All were treated with steroids and cyclophosphamide. Two had favorable outcomes and one stabilized but with severe residual neurologic disability. Conclusions: ABRA is an unusual but likely under-recognized and potentially treatable disorder. As in other reported cases, our findings suggest that many patients respond favorably to immunosuppressive therapy. We believe that all biopsy specimens consistent with primary angiitis of the central nervous system (CNS) should be further examined for vascular Aβ deposition.