[Restless legs and sleep apnea syndrome--random coincidence or causal relation?]

We report three cases of restless-legs syndrome in which by polygraphic sleep recordings an accompanying sleep-apnea syndrome was detected. Etiopathological factors, in particular a dysfunction of the sleep regulating centers in the brain stem as a cause of both diseases are discussed. Our observations suggest that a polysomnographic recording including respiration parameters should be carried out in every patient suffering from restless-legs syndrome.