Revision of a furosemide-loading vestibular-evoked myogenic potential protocol for detecting endolymphatic hydrops

Abstract

The revised FVEMP protocol using a 500 Hz tone burst stimulus and normalized amplitudes was defined as positive when IR exceeded 14.2% or when a biphasic wave could be detected after furosemide administration in cases without a detectable biphasic wave before administration.

Recent and Frequent Vertigo Attacks Produce Negative Findings on Furosemide-Loading Vestibular Evoked Myogenic Potential Testing in Meniere's Disease

“…The FVEMP examination procedure was conducted based on a previously reported method using the Neuropack system (Nihon-Kohden Co, Tokyo, Japan) ( 11 ). The active electrode was placed on the upper half of the sternocleidomastoid muscle, the reference electrode was placed on the upper manubrium sterni, and the ground electrode was placed on the forehead.…”

“…As described in previous reports, the improvement rate (IR) was obtained using the following formula: Where AB was the normalized amplitude observed before the administration of furosemide and AA was the normalized amplitude seen after the administration of furosemide ( 6 , 8 ). According to the previous study, the criteria for positivity were defined as IR > 14.2% or when the p13-n23 biphasic wave was detected only after the administration of furosemide ( 11 ). All subjects were prohibited from using diuretics and anti-vertigo drugs, which could affect the results, 24 h before examinations.…”

“…To revise the FVEMP, we studied cVEMP amplitudes that were stimulated at 250, 500, 700, 1,000, 1,500, and 2,000 Hz and were measured before and after furosemide administration in MD and normal control groups ( 11 ). The amplitudes after administration significantly increased at only 500 Hz in the subjects with MD.…”

“…Receiver operating characteristic curve analysis revealed an IR cut-off value of 14.2% at 500 Hz, with a sensitivity of 71% and a specificity of 81% for comparing MD to normal healthy subjects. Owing to this revision, the examination was more acceptable for the diagnosis of EHs in the saccule ( 11 ). On the other hand, EHs were detected in the saccule in 86% of patients with MD based on a human histopathological study and in 93% of patients with MD based on an MRI study ( 12 , 13 ).…”

Vestibular-Evoked Myogenic Potential Testing in Vestibular Localization and Diagnosis

“…47,58,59 Another application of VEMPs in MD has been in testing before and after a diuretic challenge, that is, with glycerol or furosemide; however, this procedure is not widely practiced. [63][64][65][66][67] In terms of localization of MD within the ear, abnormalities on audiovestibular tests may point to areas affected by endolymphatic hydrops, such as saccular hydrops in patients with abnormal AC cVEMPs, utricular involvement with oVEMP abnormalities, and cochlear involvement with audiological abnormalities (e.g., pure tone average or electrocochleography). In recent years, it has become possible to use magnetic resonance imaging (MRI) to visualize hydrops in the cochlea and vestibule.…”