Revaluation of the head-shaking test as a method of nystagmus provocation
Part 2 : Its diagnostic significance for the site of lesion
1984 Volume 43 Issue 2 Pages 236-242
Details
1984 Volume 43 Issue 2 Pages 236-242
The head-shaking test provokes effectively a latent spontaneous vestibular nystagmus (head-shaking nystagmus). The diagnostic significance of head-shaking nystagmus for the site of lesion was studied on 191 patients who visited our otologic clinic from 1980 to 1982 with complaints of dizziness.
1. In 78.7% of the patients of unilateral lesion, the nystagmus was directed contralateral to the site of lesion, and in 21.3%, ipsilateral.
2. In 79.3% of the patients of unilateral hearing loss, the nystagmus was directed contralateral to the site of hearing loss, and in 20.7%, ipsilateral.
3. In 96.7% of the patients with caloric abnormality, the nystagmus was directed contralateral to the site of canal paresis (CP), and in 3.3%, ipsilateral.In 4 patients with directional preponderance (DP), the nystagmus had the same direction as DP.
4. The head-shaking nystagmus, which is directed contralateral to the site of lesion, the site of hearing loss, or the site of CP, is considered as the deficiency nystagmus, while the nystagmus, which is directed ipsilateral, is considered as the recovery nystagmus. The both types of nystagmus can be distinguished from their styles of beating.
5. The biphasic nystagmus was observed in 9 patients with peripheral lesions. The 1st phase was considered to be the deficiency nystagmus, and 2nd phase, recovery nystagmus.
