Visual deterioration as presentation of subacute sclerosing panencephalitis.

A 7-year-old boy presented with deteriorating vision and macular degenerative changes. A month later he had developed unusual behaviour and increasing forgetfulness. An electroencephalogram showing periodic complexes, and high measles complement-fixation titres in the cerebrospinal fluid and blood, confirmed the diagnosis of subacute sclerosing panencephalitis. Four months after the onset of visual symptoms he started having myoclonic jerks.