An unusual intranuclear structure (? viral nucleocapsid) in the brain in subacute sclerosing panencephalitis.

A brain biopsy was examined from a 7 year old boy with subacute sclerosing panencephalitis. Intranuclear deposits of measles antigens were demonstrated in parenchymal cells by immunofluorescence. Electron microscopy showed viral nucleocapsids in nucleoliform inclusions and unusual rod-like intranuclear structures which resemble structures previously described only in tissue cultures infected with measles virus.