Circadian variation of nystagmus in healthy and sick subjects.

Rhythmic activity of various biological systems and functions have been investigated extensively. However, information about diurnal variations of the vestibular system is scarce. In the present preliminary report, diurnal variations of the spontaneous and induced nystagmus in healthy subjects and in patients with peripheral vestibular disorders have been assessed. Circadian rhythms of the vestibular responses were demonstrated. In some variables significant differences have been found between health and sick examinees. These differences may have practical clinical implications on diagnosis and treatment.