Is electroencephalographic monitoring of electroconvulsive therapy clinically useful?

Electroencephalographic (EEG) monitoring was carried out in 169 bilateral and 114 unilateral applications of electroconvulsive therapy (ECT), given to 51 patients in an everyday setting within the National Health Service by junior medical staff. In 2.5% of bilateral and 8% of unilateral applications there was disagreement between clinical and EEG assessment as to whether a fit had occurred. When an EEG fit was said to have occurred only if it lasted longer than 25 seconds, then disagreement rose to 7% in bilateral and 28% in unilateral applications; disagreement was higher with unilateral applications, as they produced more short fits than bilateral applications. If future work shows duration of seizure is clearly associated with clinical efficacy, it is suggested the case for routine EEG monitoring is greatly strengthened.