Atypical clinical and electroencephalographic pattern in a patient with subacute sclerosing panencephalitis

We describe an atypical clinical and electroencephalographic (EEG) pattern observed during the course of subacute sclerosing panencephalitis in a 14 year-old boy. In this patient with a two weeks history of partial complex seizures, the atypical EEG pattern was characterized by an initial left temporal focus which evolved to periodic lateralized epileptiform discharges (PLEDs) and, only during the 3rd and 4th weeks the typical bilateral and generalized periodic complexes appeared.