ABSTRACT

The term tracé alternant was first used in 1955 to describe in premature and newborn babies the periodic discontinuity of quiet sleep, the equivalent of non-rapid eye movement (NREM) sleep in adults. In the same period, the French school extended this notion to the oscillations of electroencephalographic (EEG) patterns associated with simultaneous modifications of arousal level, muscle tone, and neurovegetative activities in stage 2 coma. In the English-language articles, the French version of tracé alternant was converted into cyclic alternating pattern or CAP. In 1985, the term CAP was recovered to describe a physiological EEG component of NREM sleep.