Progressive multifocal leukoencephalopathy after natalizumab monotherapy.
Lindå H, von Heijne A, Major EO et al.
Editor’s note: This paper describes the case of a male patient with multiple sclerosis (MS) who developed progressive multifocal leukoencephalopathy (PML) after treatment with natalizumab. After 12 months of treatment with natalizumab, a small signal change was retrospectively noted on routine magnetic resonance imaging (MRI); at that time, JC virus DNA was not detected on polymerase chain reaction (PCR) assay of the cerebrospinal fluid (CSF).