Delayed endolymphatic hydrops: Study and review of clinical implications and surgical treatment - Brief Article

Ear, Nose & Throat Journal, Feb, 2001 by Tsun-Sheng Huang, Ching-Chen Lin

Abstract

Delayed endolymphatic hydrops (DEH) differs from Meniere's disease in that it occurs in pre-existing ear pathology in patients who have a profound unilateral or total deafness that was caused by infection, trauma, or unknown causes during childhood or adulthood. We performed a retrospective review of 160 patients with ipsilateral, contralateral, or bilateral DEH. Eighty-seven patients who did not respond to medical therapy underwent surgical treatment. Our findings indicate that the more conservative surgical procedures--endolymphatic sac surgery, cochleosacculotomy, and streptomycin perfusion--are all as effective as and less destructive than labyrinthectomy for controlling vertigo. The clinical results of this study would seem to support the observations of others that DEH and Meniere's disease are related disorders caused predominantly by cases of viral labyrinthitis with unknown etiology.

Introduction

Delayed endolymphatic hydrops (DEH) was first reported in 1975 in papers by both Nadol et al [1] and Wolfson and Leiberman. [2] The condition was named and further elaborated on by Schuknecht, who classified DEH as either ipsilateral, contralateral, or bilateral. [3] Ipsilateral DEH is characterized by the early onset of a profound or total hearing loss in one ear in conjunction with Meniere's-type vertigo. Ipsilateral DEH is often accompanied by nausea and vomiting. It is occasionally associated with tinnitus, pressure, or fullness in the same ear after a period of years has elapsed. In the contralateral expression, the patient experiences a fluctuating and progressive hearing loss--with or without Meniere's-type episodic vertigo--in the ear opposite the one that earlier experienced the hearing loss. Patients with bilateral DEH experience hearing loss in both ears some years before the onset of symptomatic endolymphatic hydrops.

The most common causes of DEH are inflammation, trauma, and unknown events during childhood. Schuknecht et al made a histopathologic analysis of the temporal bones of two patients with contralateral DEH. [4] They reported that the pathologic changes in the deaf ears were consistent with viral labyrinthitis, whereas the changes in the hearing ears were similar to those seen in Meniere's disease.

The first-line treatment is medical therapy. If DEH proves to be refractory to this, surgery is indicated. The type of surgical procedure depends on whether the patient has ipsilateral or contralateral DEH. For patients with ipsilateral DEH, labyrinthectomy has proved to be curative. For contralateral DEH, Schuknecht reported in 1978 that there was no satisfactory surgical treatment. [3] Since then, however, Hicks and Wright reported that endolymphatic sac (ELS) surgery in patients with contralateral hydrops is relatively safe, provides an excellent chance of eliminating or controlling vertigo and maintaining or improving hearing, and carries a low risk of surgical anacusis. [5] They consider ELS surgery to be the only option when symptoms of contralateral DEH are debilitating and refractory to medical treatment.

In this article, we describe our retrospective review of 160 patients with DEH. We discuss the clinical implications of medical treatment and evaluate the surgical options for those patients whose symptoms do not respond to medical therapy. We introduce alternate surgical modalities for ipsilateral DEH, and we emphasize the need for caution in the surgical treatment of contralateral and bilateral DEH.

Patients and methods

Between 1979 and late 1998, 160 cases of DEH in 161 ears were diagnosed at Chang Gung Memorial Hospital in Taipei. Of these, 105 were ipsilateral, and 54 were contralateral, and one was bilateral. Just less than half of these patients responded to conservative treatment with a combination of a vasodilator, labyrinthine sedative, diuretic, low-salt diet, and psychological support. In 87 patients (54%), symptoms were refractory to medical therapy, and they required surgical treatment. (In another case that is not included in this series, a patient whose symptoms mimicked delayed hydrops was found during surgery to have an intravestibular lipoma. [6])

As is the procedure for assessing other patients with dizziness and vertigo, the evaluation of these 160 patients included (1) a careful history, (2) an otolaryngologic examination, (3) a blood workup, (4) an audiometric profile, (5) electronystagmography (ENG) with caloric testing, (6) radiologic studies, and (7) a dehydration test if necessary.

ENG with caloric testing showed that cochlear function was generally not parallel to vestibular function, particularly in the contralateral cases. Not all of the deafened ears showed a reduced vestibular response, and the better-hearing ears did not always show a normal vestibular response.

Ipsilateral and bilateral DEH. Among the 105 patients with ipsilateral DEH, the presumed causes of hearing loss were otitis media and mastoiditis in 21 cases, sudden deafness in 12, mumps and viral labyrinthitis in 10, head injury in 10, high fever in three, acoustic trauma in three, drug intoxication in two, and anaphylactic shock in one case (table 1). There were also 35 cases caused by an unknown etiology during childhood and eight cases of unknown cause during adulthood. At their initial visit, these patients' ages ranged from 16 to 72 years (mean: 41). Their ages at the onset of hearing loss ranged from 2 to 50 years (mean: 15), and their ages at the onset of vertigo ranged from 9 to 71 years (mean: 33). The length of the delay between the onset of deafness and the onset of vertigo ranged from 2 to 53 years (mean: 22). All patients with ipsilateral DEH had normal or satisfactory hearing in the opposite ear.