Detection of peripheral vestibular disorders by the pendular rotation test in cats.
Unilateral vestibular disorders were induced in 3 cats by means of the injection of a small amount of sodium hydroxide into the middle ear, and vestibulo-ocular responses (VOR) to various kinds of pendular stimulation were investigated at 1 week and at 1, 2, 3, 4, and 5 months after the operation. The pendular rotation test was performed at frequencies of 0.025, 0.1, 0.25 and 0.5 Hz, and peak velocities of 50, 100, 150, and 200 degrees/s, and the directional preponderance of the VOR gain (DP%) was measured using a computer. DP% 1 week after the operation was still very high at each frequency and velocity of the stimulation. On the other hand, DP% more than 1 month after the operation had decreased markedly, although it increased with an increase in the velocity of stimulation at all frequencies except at 0.5 Hz, and DP% at a velocity of 200 degrees/s was still high even 5 months later. This suggests that high velocity pendular stimulation should be used to detect unilateral vestibular disorders.
Sano
R
R
Department of Otolaryngology, Yamagata University School of Medicine, Japan.
Nakamura
T
T
Kanayama
R
R
Okuyama
T
T
Koike
Y
Y
D000818:Animals; D002150:Caloric Tests; D002415:Cats; D004585:Electrooculography; D005133:Eye Movements / Q000502:physiology; D009760:Nystagmus, Physiologic / Q000502:physiology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D012399:Rotation; D013997:Time Factors; D015837:Vestibular Diseases / Q000175:diagnosis* / Q000503:physiopathology; D014724:Vestibular Function Tests / Q000379:methods*