The damped pendular rotation test in central vestibular disorders

Effects of ocular fixation on perrotatory nystagmus in damped pendular rotation test

Effects of ocular fixation on pendular rotation nystagmus were investigated in 65 patients. There were 25 with peripheral vestibular or vestibulo-cochlear disorders, 17 with central vestibular disorders, five with congenital nystagmus, 16 patients over 60 years old with vertigo in whom peripheral vestibular disorders were ruled out, however, the causes were unknown. Damped pendular rotation test (DPRT) was performed both under darkness and employing mental arithmetic and under ocular fixation. These findings were related to those of caloric vestibular suppression test (VST) by Takemori and those of optokinetic pattern test (OKP), eye tracking test (ETT), and spontaneous nystagmus. Thirteen of 17 patients with central vestibular disorders and five with congenital nystagmus showed loss of visual suppression during ocular fixation in DPRT, whereas in cases of peripheral lesions, visual suppression was observed. Loss of visual suppression during ocular fixation in DPRT was often seen in cases of brainstem and cerebellar lesions. In brainstem lesions, perrotatory nystagmus was evoked during ocular fixation, whereas no nystagmus was seen in darkness with eyes open. In cerebellar lesions, perrotatory nystagmus was partly suppressed or decreased during ocular fixation. Relationships between the direction of the visual suppression during ocular fixation in DPRT and the side of the lesion were not apparent. Ocular fixation test in DPRT has a diagnostic value not only for central lesions, but for differentiating brainstem lesion from cerebellar lesion with the findings in DPRT under darkness. The findings under ocular fixation in DPRT are closely related to those of VST in cases of caloric nystagmus.

[Central nystagmus writing during the pendular test. Findings on post-punctural symptoms after lumbar puncture (author's transl)]

The central nystagmus writing (ecriture centrale) during the pendular test is characteristically found in cerebral organic or functional lesions. Thirty patients with symptoms following lumbar puncture (L.P.) were investigated with the pendular test. In 46.6% central nystagmus writing was found 3 days after L.P. After subsiding of post L.P. troubles all the nystagmograms became normal. A control group of 30 patients without symptoms after L.P. did not show patholgic variations in the nystagmus writing during the pendular test.

The nystagmus and the therapeutic effects on early-diagnosed cases of sudden deafness

We investigated the hearing prognoses of early diagnosed cases of sudden deafness. We tried to find the most reliable factor to determine the prognosis of hearing loss. Of various possibilities that affect the prognosis; the period of onset to first examination, therapeutic manner and vestibular test findings, the findings of caloric test and spontaneous nystagmus showed much better correlation with the hearing prognosis than others. Thus, we presume the vestibular dysfunction in cases of sudden deafness may reflect the extension and severity of inner ear involvement.