Unusual electroencephalographic findings in subacute sclerosing panencephalitis: a case report.

Subacute sclerosing panencephalitis (SSPE) is a rare infectious central nervous system (CNS) disease with a poor prognosis. We reported on the case of an adolescent girl with SSPE and characteristic periodic electroencephalographic (EEG) complexes. Her neurological deficits including generalized myoclonic seizures improved after intraventricular interferon (IFN) treatment. However, unusual EEG patterns consisting of bisynchronous occipital spikes preceding periodic complexes developed in follow-up EEGs.