Abstract: Objective To explore the relationship between dizziness-vertigo and nystagmus intensity, according to the nystagmus accompanied by dizziness and/or vertigo during caloric test. Methods The relationship between dizziness and vertigo sensations and nystagmus intensity was analyzed in 399 patients with peripheral vestibular disorders,who underwent routine caloric test. The nystagmus intensity is as an index, accompanied by dizziness and/or vertigo sensations induced during caloric test. Results Warm and cold stimulation induced dizziness and vertigo and associated nystagmus overall analysis, the intensity of nystagmus was always greater than that of dizziness when vertigo occurred. The nystagmus thresholds for dizziness and vertigo induced by warm and cold air stimulation in the left ears were 4.2°/s and 5.9°/s for cold, 4.2°/s and 8°/s for warm, in the right ears were 4.6°/s and 6.2°/s for cold, 5.3°/s and 6.5°/s for warm, respectively. Three hundred ninety nine patients were subjected to alternating warm and cold stimulation in both ears for a total of 1596 times, which induced dizziness 513 times(32.14%), of which 312 times only dizziness and 201 times vertigo ten seconds after dizziness. Vertigo was induced 906 times(56.77%), of which 705 occurred directly without transitioning from dizziness to vertigo, and another 201 times vertigo occurred after ten seconds of dizziness; 378(23.68%)times did not induce dizziness and vertigo. Conclusions Vertigo corresponds to a higher nystagmus intensity threshold than dizziness, with patients showing dizziness when the nystagmus is weak and vertigo when it is stronger. Warm and cold air stimulation induced nystagmus intensity from weak to strong, and from dizziness to vertigo sensations induced at the same time, suggesting that the symptoms of dizziness and vertigo are related to the asymmetric between the two vestibular tension.

Key words: Vertigo, Dizziness, Nystagmus, Caloric test, Slow phase velocity