Ependymitis in Mumps Virus Meningitis: Electron Microscopical Studies of Cerebrospinal Fluid

Cerebrospinal fluid (CSF) sediment from six patients with mumps meningitis was examined with the electron microscope and the findings compared with those in six other cases of presumed viral meningitis or encephalitis. Ependymal cells and cytoplasmic inclusions of viral nucleocapsid-like material were found in the CSF of each of the six patients with mumps. Ependymal cells were found in only one of the CSF sediments from the other patients, and no viral inclusions were found. These findings indicate that ependymitis regularly occurs in mumps meningitis. This supports the hypothesis that mumps virus may be a cause of aqueductal stenosis and hydrocephalus in man.