The Effect of Elevated Intracranial Pressure on Frequency Tuning of Air-conducted Ocular Vestibular Myogenic Potentials in Meniere's Disease Patients.

Objective: To investigate the effect of increased intracranial pressure on ocular vestibular-evoked myogenic potential (oVEMP) amplitudes and frequency tuning in patients with Meniere's disease (MD) to elucidate whether oVEMPS recorded under such conditions could provide a simple and accurate diagnostic test for MD. Setting: Tertiary referral center for otology and neurotology. Patients: Ten patients with certain unilateral MD (mean age = 48.2 yr, range 25-75 yr, 6 males and 4 females) as confirmed by a locally enhanced inner ear MRI (LEIM) were enrolled in this study. Design: Air-conducted tone-burst oVEMP amplitudes were measured in response to 500 Hz and 1000 Hz in the horizontal plane (0 degree), a 20-degree head-down position. Results: Tilting the patients from the horizontal position to the 20-degree head-down position led to a large reduction in oVEMP amplitudes to the 500 Hz tone burst (3.02 [mu]V vs 1.17 [mu]V, p = 0.005) and to a smaller one in the 1000 Hz tone burst (2.28 [mu]V vs 1.78 [mu]V, p = 0.013) in the Meniere's ear. Accordingly, the 500/1000 Hz frequency-tuning ratio was significantly decreased in the Meniere's ear as a result of this manoeuver (1.36 vs 0.75, p = 0.005). Conclusion: oVEMP amplitudes and frequency tuning in MD patients show a similar behavior to that found in healthy control subjects. oVEMP testing of putative MD patients in the tilted position is therefore unlikely to be diagnostically useful. Copyright (C) 2017 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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