A 64-year-old previously health gentleman was admitted with a 1.5 month history of severe headache, confusion, personality changes and progressive cognitive decline. Physical examination revealed ataxia. Laboratory test showed normal or negative ESR, autoimmune and infective profiles. Cerebrospinal fluid (CSF) protein concentration was 97 mg/dl, white cell count was 23/ul (90% lymphocytes); there were no atypical cells and infective tests were negative. Chest X-ray, echocardiogram, and duplex carotid ultrasonogram were unremarkable. Enhanced brain MRI showed diffuse bilateral leptomeningeal enhancement involving the cerebrum and the cerebellum, multiple infarcts, and patchy T2-weighted white matter signal abnormality. Cerebral angiography was normal. An open brain biopsy showed granulomatous leptomeningeal and intraparenchymal vasculitis as well as infarcts and vascular beta-A4 amyloid deposition consistent with cerebral amyloid angiopathy (CAA). Stains of biopsy specimens were negative for fungi and mycobacteria. Amyloid-related primary central nervous system vasculitis (PCNSV) was diagnosed and the patient was treated with oral prednisone (40 mg/day tapering) and pulse cyclophosphamide for 14 months. His neurologic state progressively improved within the first 3 months. He became much less confused, his headache resolved and he was able to resume many of his previous activities. A repeat MRI showed complete resolution of leptomeningeal enhancement and no new infarcts. At the final follow up visit 12 months later, the patients was off treatment and had only a minimal residual disability.
About a quarter of patients with biopsy-proven PCNSV have evidence of cerebral amyloid vascular deposition. These patients usually have cognitive dysfunction and/or seizures at presentation, high concentrations of CSF protein, and enhancing leptomeningeal lesions on MRI. Angiography is usually negative because the vasculitis is confined to small vessels below the power of resolution of conventional angiography. Cerebral biopsy is thus required for the diagnosis. Brain biopsy shows a granulomatous vasculitis with amyloid deposits. Response to immunosuppressive treatment is usually favorable with good outcome.
Disclosure of Interest None declared