To describe the outcomes of electroencephalography requested by general adult psychiatry over a 12-month period.
187 electroencephalograms (EEGs) were performed. In 71%, the request was to look for evidence of epilepsy. In 22%, it was to determine whether there was organic brain dysfunction. In only one patient was unequivocal evidence of an epileptic focus found. A further 11 patients demonstrated a liability to epilepsy. In none of the 33 patients where aggression was mentioned on the request form were any diagnostic features found.
The yield of EEG in psychiatry is low. To diagnose epilepsy, clinicians should continue to rely on the clinical history of attacks and not the EEG. The presence of aggression is rarely associated with meaningful EEG changes.