[Significance of postrotatorius II within the scope of the rotatory test]

In 68 patients suffering from acute unilateral vestibular disorders 168 electronystagmograms could be analysed paying special attention to the nystagmographic reactions in the second postrotatory period. When the postrotatorius II was directed to the affected side (in 25% of our cases) this was an indication for an advanced extent of central compensation in the electronystagmogram. There was a good correlation between the postrotatorius II and the other nystagmographic reactions in the per- and postrotatory periods. However, the occurrence of the postrotatorius II agreed neither with the results of the vestibulo-spinal tests (Romberg, Unterberger) nor with the nystagmus findings observed with Frenzel's glasses. In many cases a latent spontaneous nystagmus could be detected with the postrotatorius II. Including the second postrotatory period in the evaluation of the electronystagmograms provides additional information permitting a much better assessment of the extent of central compensation.