[Comments on the rules by Rechtschaffen and Kales about the visual scoring of sleep EEG recordings]

The rules by Rechtschaffen and Kales present numerous problems; they sometimes even contradict physiological facts. This is due on the one hand to the manual being limited to central leads only, and on the other hand to rules which are partly too narrow, partly too broad and partly too complex. Furthermore, there are situations and physiological facts for which the manual does not have any rules. The exclusive evaluation of central leads has to result in a different scoring for numerous epoches of stages than an evaluation of leads from all hemisphere electrodes. In addition, frontal or occipital graphoelements such as mitten-pattern and sleep lambda are not even included. It is often difficult to make a distinction between an "alpha-sleep type" and pre-arousals (micro-arousals); the latter also applies to alpha groups in REM sleep. In particular however, if frontal, parietal and occipital leads are included, then the stage 2, above all however stages 3 and 4 will be represented more frequently, as sigma spindles, K-complexes and delta-waves are frequently found in a recognizable form only in the non-central leads. Further difficulties result from different paper speeds of 15 or 10 mm/s and from the rule concerning the allocation from stage 1 to stages 2 or REM.