Complaints about sleep disturbances are a common every-day problem in the general practitioner's surgery. Only a few patients need a thorough expert examination in a special sleep laboratory. Thanks to EEG, which makes available a continuous record of uninterrupted sleep cycles, knowledge of the physiology of sleep now includes important information about the normal circadian rhythm of waking and sleeping, the alternation of REM and non-REM periods, and the depth of the individual sleep cycles. EEG results are also an important basis for checking the effect of sleeping drugs. Analysis of sleep disturbances is based on the formal distinction between hypersomnia, and hyposomnia and parasomnia. Etiologically, a distinction must be made between exogenic and endogenic sleep disturbances and attention given to the fact that disturbances of night sleep also affect vigilance on the following day. These considerations are also important for the use of sleeping drugs, whose half-life and biological effect allow a useful differentiation between substances giving impulses to sleep, sleep-inducing drugs, and those enabling uninterrupted sleep during night-time. Sleep disturbances combined with certain other symptoms belong to particular syndromes in which it may be necessary to use sleeping drugs, but these should only be used in combination with other drugs, in order to reduce the risk of side effects, tolerance changes, dependence and addiction with long-term treatment. When a combination of different drugs is given, interference through interaction with lipid or protein binding, and induction or enzyme breakdown in the liver should be taken into account.
Circadian Rhythm Dreams