Detection of mumps virus RNA in cerebrospinal fluid of patients with neuromyelitis optica

Neuromyelitis optica (NMO) is an acute inflammatory disease that preferentially involves the optic nerves and spinal cord. Although many infectious agents, including mumps virus, are postulated to have a role in the pathogenesis of multiple sclerosis (MS), the relationship between NMO and infectious agents remains uncertain. To investigate the relationship between NMO and viruses that have special affinity for the central nervous system, we performed a nested polymerase chain reaction (PCR) to detect mumps virus or enterovirus RNA in cerebrospinal fluid samples from 13 patients with MS, 8 with NMO and 20 with other neurological diseases (ONDs). Nested PCR was positive for mumps virus in 2 (25%) of NMO patients, but in none of those with MS and ONDs. Moreover, nested PCR results became negative in the remission phase in the two PCR-positive NMO patients. Mumps virus may have some role in the pathogenesis of NMO.