Analysis of Vertical Semicircular Canal Rotational Test in Healthy Adults

Han, Gyu Cheol

Abstract

BACKGROUND AND OBJECTIVES: Vestibular function tests of the semicircular canal (SCC) are limited to horizontal SCC since stimulating a vertical SCC is difficult. The purpose of this study is to develop a vestibular function test of vertical SCC and analyze its function in healthy adults. MATERIAL AND METHODS: Thirty healthy adults were placed down in supine position on a rotating table with their heads turned 45 degrees to left or 45 degrees to right side. The table was rotated in a sinusoidal rotational mode at 0.05 Hz and 0.1 Hz frequency. Nystagmus was observed through a videooculographic device or Frenzel glasses and recorded with a romputerized electronystagmography. An analysis was made on the vertical nystagmus.
RESULTS
Rotatory nystagmus was observed: the slow component of eye velocity and the gain were increased at a higher frequency while the phase was decreased at higher frequency (p<0.05). Gain, phase and directional preponderance did not show any significant difference at each head position.
CONCLUSION
Resulting nystagmus from the rotating chair stimulation on a vertical SCC has been analyzed. The test can be utilized to analyze the function of a vertical SCC as a positional/positioning test, a head impulse or self rotation test.