[Value of the rotation test in acute unilateral vestibular disorders]

The electronystagmographically recorded response of the spontaneous nystagmus and of the per- and postrotatory nystagmus were examined in 70 patients suffering from acute unilateral vestibular disorders. Within a short time the SPN declined logarithmically compared to the reduction of the perrotatory directional preponderance. But the postrotatory nystagmus levels changed only a little in the course of time. The patient's symptoms did not correlate with results of the rotatory test or the intensity of the SPN. The graphs of both parameters (maximal velocity of the slow nystagmus phase and nystagmus frequency in culmination range) which had been analysed showed an almost identical course. Obviously two independent functions are recorded by the caloric and rotatory vestibular test: the rotatory test is said to describe the extent of the central compensation. The lack of conformity in the results of various vestibular tests, including the rotating chair, limit the reliability of the individual tests and indicate that different methods of investigation should always be carried out especially in medico-legal cases.