An unusual case of subacute sclerosing panencephalitis

A 25-year-old man was admitted following deterioration in behavior and onset of blindness. He soon became comatose and died 6 weeks later. Brain biopsy showed nuclear inclusion bodies resembling viral capsids, astrocytosis and perivascular lymphocytic cuffing but no demyelination. The diagnosis of subacute sclerosing panencephalitis was made on finding: measles virus antigens in both serum and cerebrospinal fluid, the identification of measles RNA sequences in brain tissue by the polymerase chain reaction, and intense, oligoclonal, IgG-banding in the CSF. However, the relatively advanced age of the patient, the absence of myoclonus and the nondistinctive EEG profile lacking synchronous bursts of high-voltage slow and sharp waves, are unusual.