How long should a routine EEG be?

Cost-benefit analysis in neurology practice deserves continual reassessment. One example is the duration of a routine electroencephalography (EEG) required to optimise accuracy of diagnosis. Recommended guidelines of recording a routine EEG for 20 or more minutes are not based on scientific evidence. In many countries, EEG is not economically viable with costs outweighing financial remuneration. We prospectively studied 420 consecutive routine EEGs to see if a shorter record decreased diagnostic accuracy. A carefully structured 15 min routine EEG protocol produced comparable results with the 25 min recording. Shorter routine EEGs would make EEG more cost effective without compromising diagnostic accuracy.