Detection of delayed endolymphatic hydrops by the furosemide test

Delayed endolymphatic hydrops, an entity which can be differentiated from Meniere's disease, was first reported simultaneously by Nadol et al. (1975) and Wolfson & Leiberman (1975) and specified by Schuknecht (1978). They diagnosed it from the anamnesis of patients and confirmed the hydropic condition of the labyrinth solely by evidence obtained from surgical procedures such as labyrinthectomy. The aim of the present study was to emphasize the usefulness of the furosemide test for distinguishing this entity before surgery by detecting the hydropic condition in the labyrinth. In these 3 years, we encountered 11 cases of endolymphatic hydrops, 9 ipsilateral and 2 contralateral, in our clinic (Univ. of Tokyo Hospital). Among the ipsilateral cases, the estimated genesis of pre-existing hearing loss was most frequent in mumps (44%). The result of the furosemide test in this group was 89% positive. On the basis of this result, we have been able to choose the method of treatment, i.e. 4 cases treated by epidural shunt operation on the endolymphatic sac, 2 by labyrinthectomy, one by cochleosacculotomy and 2 by medication with steroids and diuretics. In the 2 contralateral cases, one was treated by epidural shunt and the other by medication. The authors are therefore able to confirm the usefulness of the furosemide test for detecting delayed endolymphatic hydrops.