[Atypical electroencephalographic activity in terminal phase subacute sclerosing panencephalitis].

The authors describe the evolution of the EEG during a 3-yr period in a case of subacute sclerosing panencephalitis (SSPE) revealed by epilepsy in a 9 yr-old boy. During the first 2 yr, the EEG was markedly abnormal (diffuse spike-waves, delta rhythms). During the static period, it looked like a continuous non-convulsive status epilepticus. The typical periodic abnormal activity only appeared at the terminal stage, and after a Valium test. Then slow wave complexes persisted on a dysrhythmic background. This type of EEG has never been described; our study stressed the efficacy of the Valium test in this particular case.