Technical standards for digital electroencephalogram recording in epilepsy practice

With the advent of digital technology in the recording of the electroencephalogram (EEG) in the last decade, analogue paper-EEG machines have all but disappeared. While there are several advantages of digital EEG over its analog counterpart, like being paperless and therefore easy to store and the ability to change montages and filter settings during review, there is wide disparity in the standards of EEG recording, display and reporting in laboratories across the country. Colorful brain maps conveying little meaning are usually appended to reports. This article reviews the minimum standards that must be observed for recording digital EEG as recommended by the International Federation of Clinical Neurophysiology (IFCN) and illustrates the importance of use of appropriate derivations, montages, filters and gains during recording and review of digital EEG in the context of evaluation of patients with suspected epilepsy.