The caloric test is usually performed in open-loop system. Although the closed loop caloric test has many advantage, which can e used in the patient with perforation of tympanic membrane and middle ear pathology, but it has not been used
popularly.
The
purposes of this study were to establish normal responses for normal subject using a closed-loop caloric irrigator and to know test-retest correlations of responses to closed-loop irrigations.
Normal subjects(n=55) were studied with eye-opened in dark field(n=35) and eye-closed in dark field(n=20). We used Brooder-Grams closed loop irrigator with 27(0.5℃ and 44(0.5℃ water, irrigation times of 40seconds, and nystagmus was detected
more
than
120 seconds by Electronystagmography, Using Jongkees' formula, directional preponderance, canal paresis and temperature effect were analysed.
As a result, the eye-opened test group had more correct response, and test-retest was highly correlated. And directional prepondrance was distributed in less than 30% and canal paresis was distributed in less than 29%(p<0.05). It was found that
water
temperature was appropriate because temperature effect was distributed in less than 30%.
As a conclusion, the closed loop caloric test has many advantages and good test-retest reliability, therefore it is clinically useful method. (Korean J otolaryngol 39 : 2, 1996)
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