A case of atypical progressive multifocal encephalopathy mimicking acute ischemic stroke: case report and review of literature

Progressive multifocal encephalopathy (PML) is a rare but often fatal infectious brain disease caused by the reactivation of John Cunningham polyomavirus. Reactivation occurs in immunocompromised individuals with AIDS and leukemia, on chemotherapy or being treated with immunosuppressant drugs (e.g. monoclonal antibodies). Cases of PML have been described in patients treated with natalizumab, efalizumab and rituximab used, respectively, for the treatment of (1) multiple sclerosis, (2) psoriasis and (3) haematological malignancies or systemic autoimmune diseases (rheumatoid arthritis and systemic lupus erythematosus). The authors describe an unusual case of acute brainstem and cerebellar PML following chemotherapy for chronic lymphatic leukemia diagnosed 4 years before the onset of PML in a 75-year-old man. The patient was treated with high dose chemotherapy and rituximab with complete response. The onset of symptoms of PML was very rapid and occurred after more than two years from last rituximab infusion; patient had a sudden neurological deterioration, with rapid progression to death in about a month from the onset of symptoms. Lesions were localized in the cerebellum, brainstem and such pattern has been reported in very few cases in the literature