Atypical presentation of subacute sclerosing panencephalitis in 3 patients.

Experience with some of our patients suggests that the diagnosis of subacute sclerosing panencephalitis (SSPE) may be made early and confirmed by the demonstration of high levels of measles complement-fixing antibodies in the cerebrospinal fluid (CSF) and serum, in the absence of classic clinical, electroencephalographic or brain biopsy support for the diagnosis. It is not known when the measles-specific antibodies first appear in the CSF, but these 3 atypical cases suggest that they were present in high titre early in the disease.