Subacute Sclerosing Panencephalitis

Abstract

Laboratory findings from a new case of subacute sclerosing panencephalitis included (1) burst-suppression electroencephalographic pattern, (2) elevation of the spinal fluid γ-globulin level, and (3) increased measles serum and spinal fluid antibody titers. These findings were examined in light of clinical features suggesting progressive gray and white matter involvement. Electron microscopical study of brain biopsy material revealed unusual nuclear inclusions in the nerve cells in addition to the typical paramyxovirus nucleocapsids. When compared with in vitro systems, viral maturation in brain appeared to be blocked at the cell membrane level and, consequently, no complete virus was formed. Possibly a partial defect in synthesis of the fuzzy nucleocapsids was also present. This peculiar incomplete viral maturation may be the expression of a genetic variant of measles virus.