Vibration induced nystagmus in normal subjects and in patients with dizziness. A videonystagmography study.
OBJECTIVE
To analyze the incidence and characteristics of vibration-induced nystagmus in normal subjects and in patients with vertigo.


METHODS
This is a prospective analysis of the effect of vibration on several points of the skull in 38 normal subjects, 10 patients who had undergone labyrinthectomy and 125 consecutive patients with dizziness referred to a tertiary care center. Nystagmus was documented and its corresponding slow phase velocity measured with a videonystagmography system.


RESULTS
In 81.6% of normal subjects and 80.8% of all patients, nystagmus could be provoked by stimulation of at least one of the points on the skull to which the vibrator was applied. In normals, however, no subject had nystagmus greater than 2.8 degrees s-1 whereas 35.2% of patients did.


CONCLUSIONS
The value of the slow-phase velocity of vibration-induced nystagmus can be used to identify a sizeable proportion of patients with a vestibular disorders. Vibration-induced nystagmus is a frequent sign in patients with dizziness and can provide complimentary information about vestibular system function.
Perez
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Clínica Universitaria de Navarra, Dpto. de ORL, Pio XII 36, 31008 Pamplona, Navarra, Spain. nperezfer@unav.es
D000328:Adult; D004244:Dizziness / Q000150:complications*; D004584:Electronystagmography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000150:complications* / Q000175:diagnosis / Q000209:etiology*; D014732:Vibration / Q000009:adverse effects*; D014743:Videotape Recording