[Clinical comparison of perrotatory and postrotatory nystagmus characteristics (author's transl)].

Rotatory stimulation is a physiological stimulation of the vestibular canalicular organs. In every day's neurootological routine it is applied in sinusoidal, triangular and trapezoidal shape. The rotatory intensity damping test (RIDT) applies a perrotatory and postrotatory test combination of a trapezoidal stimulus pattern. Thus the perrotatory as well as the postrotatory nystagmus can be recorded during several phases of the after phenomena. In terms of acceleration/time plots the supraliminal perrotatory acceleration exhibits a rectangular or step-like stimulus characteristic. The supramaximal postrotatory stimulus however has a needle-like impulse pattern. The nystagmus reaction being recorded by the ENG is evaluated according to frequency or beat-rate distributions. The perrotatory nystagmus can be linearily optimalized in a linear to linear plot during its maximal reactional dynamics. The postrotatory nystagmus distribution can also be linearily graphed in a nomogram. However this nomogram is a log.log intensity/time-chart. This paper clinically compares per- and postrotatory reactions of the rotatory intensity damping test. It can be seen that this test adds important information to the clinical study of the dizzy patient.