[Physiological spontaneous and positional nystagmus. electronystagmographic examinations concerning type, frequency...

120 subjects were selected from a large number of healthy persons on the grounds of their medical history and preexaminations including audiogram, which excluded the possibility of previous cochelo-vestibular illness. These 120 healthy persons were examined by means of electronystagmography. We were searching for spontaneous and positional nystagmus in 5 positions with open eyes in darkness and with closed eyes. 50% proved to have a horizontal and 82% a vertical spontaneous nystagmus in at least 1 position. The sex had no influence on the frequency and there was no difference in results under smokers and non-smokers. There was the same frequency of nystagmus directed to right and left. We conclude that there is a physiological horizontal spontaneous nystagmus of low intensity if fixation is completedly excluded. In our opinion it is not possible to determine a certain level of intensity above which a spontaneous nystagmus is pathological as the intensity of nystagmus is essentially dependent upon non-vestibular elements.