[A case of subtentorial progressive multifocal leucoencephalopathy in a patient treated with natalizumab].

This paper presents a case report of subtentorial progressive multifocal leukoencephalopathy (PML) in a 26-year-old female patient treated with natalizumab. The evolution of clinical features, neuroimaging data and treatment as well as the development of immune reconstitution inflammatory syndrome (IRIS) are described. This case emphasizes the importance to keep accurately the risk management plan during natalizumab treatment. This includes performing MRI scans in order to detect changes typical for PML at the earliest (preclinical) stage in time.