Ect induced EEG seizure: validity of duration estimation by last spike.

The seizure EEG records of 25 depressives receiving ECT were 'blindly' rated by two trained raters using a uniform definition of seizure endpoint. The EEG seizure duration estimates were validated against five expected relationships. EEG seizure duration correlated with and was more than motor seizure duration, reduced over the course of ECTs, was consistent within subjects, and negatively varied with age. Within clinical constraints, the method of seizure duration estimation by the last spike is valid.