February 3, 1984

Fast Fourier Transformation of EEG Data

Author Affiliations

University of California San Francisco

JAMA. 1984;251(5):601. doi:10.1001/jama.1984.03340290021005

To the Editor.—  Several opinions expressed by the Diagnostic and Therapeutic Technology Assessment (DATTA) panel on the subject of intraoperative quantitative EEG monitoring1 might be considered controversial. The actual technique, Fast Fourier transform (FFT) of EEG data, is not per se a quantification of EEG data but merely a reformatting of data into component frequencies. This transformation is useful because many pathological EEG patterns produce spectral patterns that can be easily recognized without the extensive training required to interpret routine EEG tracings. The reformatting of EEG into respective frequency spectral patterns allows enormous compression in display of data over time, providing easy visualization of temporal trends. The currently available commercial EEG-FFT monitors are easy to set up and operate, obviating the need for a technician-operator, but do not provide as many EEG data channels as do routine clinical EEG recorders.The statement in the DATTA opinion that standard EEG