3D analysis of nystagmus during peripheral vertiginous attacks.

In order to localize the site of lesion of peripheral vertigo, 3D analysis of nystagmus during peripheral vertiginous attacks was carried out. In comparison between the three components, the horizontal component had the largest ratio in each disease. Spontaneous nystagmus was directed toward the affected side in 3 cases and to the opposite side in 15. In patients with Menière's disease (MD), all subjects had horizontal and torsional components and had almost the same slow phase velocity in these two components. In patients with vestibular neuritis (VN) and Hunt's syndrome (HS), nystagmus was directed toward the opposite side. Furthermore, in VN, all subjects had an upward component, in addition to horizontal and torsional components. Inferring the focus from the character of nystagmus, it is speculated that the pathological changes are located in the entire inner ear in MD, whereas in VN the lesion is located in the horizontal and anterior semicircular canal or the superior vestibular nerve.