The Effect of Elevated Intracranial Pressure on Frequency Tuning of Air-Conducted Ocular Vestibular Myogenic Potentials in Ménière's Disease Patients
To investigate the effect of increased intracranial pressure on ocular vestibular-evoked myogenic potential (oVEMP) amplitudes and frequency tuning in patients with Ménière'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 μV vs 1.17 μV, p = 0.005) and to a smaller one in the 1000 Hz tone burst (2.28 μV vs 1.78 μV, p = 0.013) in the Ménière's ear. Accordingly, the 500/1000 Hz frequency–tuning ratio was significantly decreased in the Ménière'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.