EEG in psychiatric practice : to do or not to do ?

The first electro encephalo graphy (EEG) on a human was reported by Hans Berger in 1920. The fundamental principle of EEG is to record the electrical activity produced by the brain, using electrodes. In considering the role of EEG in psychiatry almost 25 years later, Dennis Williams (1954) observed that studies of EEG recordings had offered the clinical psychiatrist little of positive value. He suggested several reasons for this: EEG does not give a true record of cerebral action potentials; attempts at correlating EEG recordings from millions of cells, the electrical activity of which was not understood, with patients’ clinical picture proved meaningless; the recording techniques used were crude; and EEG records simple physiological changes in neuronal activity which are not reflected in the complex integration of the human brain. Nevertheless, Williams did not dismiss EEG out of hand. He outlined its usefulness in the exclusion of gross organic disorder; the study and modification of local cerebral disorders related to abnormal behaviour; the correlation of changes in EEG recordings with single aspects of temperament or personality; and the use of activation techniques to demonstrate hidden pathologies. There have been technological advances since his erudite article was published, but the fundamental problems remain. In this article, we focus on the role of EEG in current psychiatric practice, EEG findings in specific psychiatric syndromes, clinical indications for requesting EEG, and interpretations of EEG recordings. We will also highlight measures to ensure appropriate and competent use of EEG in the routine clinical practice of psychiatrists.