Early ependymal changes in experimental hydrocephalus after mumps virus inoculation in hamsters

Summary To elucidate the pathogenesis of early ventricular dilatation in hydrocephalus, we examined early morphological changes in ependymal layers at the lateral ventricles in suckling hamsters without aqueductal stenosis 5 days after the intracerebral inoculation of mumps virus. Mumps virus antigen was detectable in all ependymal cells. The ependymal cilia had almost disappeared and only the microvilli remained. A number of supra-ependymal cells were also observed on the surface of the lateral ventricles. Transmission electron microscopy revealed intracytoplasmic viral-like inclusions in the infected ependymal cells. These results suggest that functional and morphological disturbances in infected ependymal cells may cause early ventricular dilatation before aqueductal stenosis occurs.Supported by a Grant-in-Aid from the Japanese Ministry of Health and Welfare for scientific research into intractable hydrocephalus,-and by a Grant-in-Aid for scientific research from the Ministry of Education, Japan (C.No. 02670435)