상반된 결과를 보이는 온도안진검사와 비디오 두부충동검사

Background and Objectives: The caloric test has been useful method to recognize the loss of peripheral vestibular function. The video head impulse test (vHIT) is also very simple and useful method to detect the peripheral vestibular loss by observing the corrective saccade as well as by measuring the gain of vestibulo-ocular reflex (VOR). But the results between these two tests can be different, depending on the functional status of clinical entity of dizziness. In this study, cases with different results between two tests were categorized to find out the further diagnostic value of these two tests and have useful insight for pathophysiology of the vestibular disease. Materials and Methods: 211 ears from 201 patients of dizziness who both bithermal caloric test and vHIT were performed, were included. vHIT was performed using ICS impulse^® (ICS impulse^®, Otometrics, Taastrup, Denmark) on horizontal plane and was repeated about 20 times in each direction randomly. Peak head velocity was controlled as 150-200 degree/second by monitoring the recording of head velocity during the test. Canal paresis (CP) more than 25% in caloric test and the presence of corrective saccade with low gain (less than 0.8) in vHIT were decided as abnormal. Clinical findings of the patients with different results between caloric test and vHIT were reviewed and categorized according to the causes of dizziness. Results: The results between caloric test and vHIT were opposite in 32.2% (68/211 ears) which were normal vHIT with canal paresis (‘CP+ & vHIT-’) in 92.6% (63 ears) and abnormal vHIT without canal paresis (‘CP- & vHIT+’) in 7.4% (5 ears). 63 ears of ‘CP+ & vHIT-’ included Meniere’s disease (32 ears, 50.8%), benign recurrent vertigo (12 ears, 19%), positional vertigo of unknown cause (9 ears, 14.3%) and other causes of dizziness (10 ears, 15.9%). In case of 55 ears of Meniere’s disease included in this study, the results were opposite in 32 ears (58.2%) which all of them were ‘CP+ & vHIT-’. ‘CP- & vHIT+’ were only 5 ears, which were acute vertigo syndrome in 2 ears, opposite ears of unilateral vestibular loss in 2 ears, and unknown cause of dizziness in 1 ear. Conclusions: In 32.2% of dizzy patients, the loss of VOR depends on the frequency range of VOR, and ‘CP+ & vHIT-’ is the most common pattern. The most common clinical entity of ‘CP+ & vHIT-’ is Meniere’s disease, but the frequency selective loss of VOR occurs in variety of causes of dizziness.. (J Clinical Otolaryngol 2016;27:269–274)