The Furosemide VOR Test for Meniere's Disease

Clinical study of elderly patients with Meniere's and related diseases

In order to study the characteristics of elderly patients (70 or over at onset) with endolymphatic hydrops disorders, we selected six patients with Meniere's disease (MD), five patients with delayed endolymphatic hydrops (DEH), and two patients with syphilis of the labyrinth (SL) from 7112 patients who had visited the Neurotological Clinic of the Toyama Medical and Pharmaceutical University Hospital during 1979-1998. Clinical features were characterized as follows: (1) Since 1990, the proportion of elderly patients increased as lifespans lengthened. (2) A narrow fluctuation in hearing, low positive rate on glycerol test, high positive rate of dominant-SP in EcochG, and the moderate abnormal rate of the oculomotor system tests were found. (3) The prognosis was relatively good. From these neurotological observations, it could be concluded that elderly patients with endolymphatic hydrops disorders were characterized by the multipathological finding of the endolymphatic hydrops and the complications of CNS disorders.

Electrocochleography in syphilitic hearing loss

Syphilitic labyrinthitis presents such symptoms as hearing loss, tinnitus, vertigo and/or dizziness, and is well known as one of the endolymphatic hydropic diseases. In order to elucidate the relationship between syphilitic hydrops and ECochG findings, we performed ECochG in patients with syphilis following our previously reported study of patients with Meniere's disease. Twenty-two patients who have been serologically and clinically diagnosed as having syphilitic labyrinthitis were examined with ECochG between December, 1982 and November, 1991. Of the 27 ears tested with ECochG, 2 showed no response due to severe hearing loss, and increased SP (SP/AP ratio > 0.37) was observed in 14 (56.0%) out of the remaining 25 ears. The SP/AP ratio of patients with syphilitic labyrinthitis was not significantly different from that of the patients with Meniere's disease or delayed endolymphatic hydrops, while it was significantly higher than that of the patients with sudden deafness and other types of sensorineural hearing loss. We conclude that the electrocochleographic features of endolymphatic syphilitic lesions resemble those in Meniere's disease.

Furosemide VOR test for the detection of endolymphatic hydrops

In order to detect endolymphatic hydrops, we applied three neuro-otologic examination methods, including the furosemide VOR test, the glycerol dehydration test, and electrocochleography in 61 patients with unilateral Menière's disease, 21 patients with delayed endolymphatic hydrops, and 10 patients with syphilitic labyrinthitis. The positive rate of the furosemide VOR test in patients with endolymphatic hydrops was more than 50%. Inconsistencies were observed between the results of the furosemide VOR test, the glycerol test and/or electrocochleography. Therefore, combined test battery of these tests is useful clinically for detecting endolymphatic hydrops in the vestibular and cochlear systems.

Otoneurological findings in inner ear syphilis

Eighty-one ears in 48 patients who had had ear syphilis for the past ten years were studied and otoneurological examinations reviewed. Twenty-five of 48 cases complained of vertigo, 13 of giddiness and/or unsteadiness, and 10 cases denied dizziness. Approximately one half of the patients had abnormal findings on primary equilibrium examinations, such as Mann's test and stepping test. Spontaneous nystagmus and positional nystagmus were frequently seen on electronystagmographic examinations. Many patients showed abnormal responses to the bithermal caloric test and pendular rotation (VOR) test. Moreover, 5 of 8 patients had positive furosemide VOR tests. On transtympanic electrocochleography, 13 of 22 ears demonstrated a dominant -SP response. Eleven of 26 ears had positive findings on an intravenously administered glycerol test. In conclusion, some cases of inner ear syphilis show the characteristic findings of endolymphatic hydrops.