Clinical Usefulness of Vestibular Evoked Myogenic Potential in Unilateral Meniere's Disease / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Because the saccule, next to the cochlea, is the second most frequent site of hydrops formation, we evaluated whether vestibular evoked myogenic potential (VEMP) responses can reflect the diagnosis and the stage of Meniere's disease. SUBJECTS AND METHOD: Retrospectively, we analyzed the results of VEMP in 40 patients (11 men and 29 women) with unilateral definite Meniere's disease. All subjects underwent VEMP testing using ipsilateral 500 Hz-tone burst sound with 90 dBnHL (rise/fall time=2 msec, plateau time=3 msec). RESULTS: VEMP was present in 92.5% of Meniere's affected ear (37/40). The latency of p13 of affected ears in patients with Meniere's disease was significantly prolonged than that of normal ears in the control group (p=0.05). However, no relationship was found in latencies of p13, n23, and interpeak latency among groups classified by the stage of Meniere's disease. In the patients with Meniere's disease, the mean interaural amplitude difference (IAD) ratio was 23.9+/-16.9%. The IAD ratio of patients with Meniere's disease was larger than that of the control group, but it is statistically insignificant (p=0.133). CONCLUSION: Prolonged p13 latency of VEMP was a pathognomic finding for Meniere's disease in this study.

Comparative Study of the Sinusoidadal Harmonic Acceleration Test andthe Caloric Test in Peripheral Vestibular Disorders / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The shinusoidal harmonic acceleration (SHA) test is known to be useful for differentiating peripheral and central disorders and monitoring the progress of vestibular diseases. However, it is not fully known how SHA test results correlate with the degree of caloric response, which have been widely used and accepted as a standard test in evaluating vestibular functions. This study was designed to investigate the relationship between SHA test and caloric test in an attempt to further elucidate the clinical significance of SHA test. MATERIALS AND METHODS: Fifty-four patients who were diagnosed with peripheral vestibular disorder at Asan Medical Center participated in this study. All patients underwent caloric tests and SHA tests. The results of both tests were compared. RESULTS: The present study reveals that the results of the SHA test in peripheral vestibular disorder are correlated with those of the caloric test, that is, patients with unilateral canal paresis in the caloric test also tend to show phase leads at lower frequency and low response gain in the SHA test. CONCLUSION: This study could be used as a basis for further studies and for the clinical use of the SHA test.