HSC Section 8_April 2017

throughout the cases, the thickness of the round window

membrane may be the most important reason determin-

ing permeability. Thus, a thickened or false round win-

dow membrane could have obscured drug passage,

which may be missed under the operating microscope.

Another possible reason is that large endolymphatic

hydrops in the vestibule may prevent the drug from

moving into the vestibule. That has been shown by

direct visualization of the blocked movement of intra-

tympanically administered gadolinium by three-

dimensional fluid-attenuated inversion recovery (3D-

FLAIR) MRI.

This could be supported by the fact that

ETG was carried out at the time of a recurrent severe

vertigo attack in most cases.

With regard to why ETG improved some cases,

although no definite problem was found or corrected in

the middle ear space, the increased contact time of gen-

tamicin with the round window membrane should be

considered. A previous study revealed that gadolinium

contrast medium stayed in middle ear cavity for far less

than 1 hour.

By applying gentamicin-soaked gelfoam

directly on the round window membrane, the contact

time could be extended considerably.

ETG seems to be necessary for patients who failed to

achieve sufficient attenuation of vestibular function even

after three or four rounds of ITG. For intractable cases

even with profound ipsilateral canal paresis after ITG/

ETG, definitive surgical ablations could be necessary

because ITG/ETG could not achieve complete ablation of

vestibular function. In addition, ETG or definite ablative

procedures could provide additional information about

undiscovered or missed disease. One patient experienced

recurrent vertigo and a Tumarkin attack even after three

rounds of ITG. Unilateral hearing loss had started more

than 10 years previously. It was progressive, and the sub-

ject has been completely deaf for the past 3 years. Unilat-

eral weakness was already 77% on a bithermal caloric

test prior to ITG. Because this patient had undergone

brain MRIs twice during the last 2 years before visiting

our clinic due to fear of cerebrovascular disorders, which

were reviewed, another request for MRI was not ordered,

although the previous ones were not thin-sectioned and

did not include contrast enhancement. An incidental

intralabyrinthine schwannoma was found during the lab-

yrinthectomy. This case teaches the importance of a high

index of suspicion for Menie`re’s syndrome caused by

tumors and the futility or even danger of simply repeated

injections. Moreover, ETG is helpful for patients who

have a history of previous surgery or inflammation in the

middle ear cavity. Previous studies have reported bone

dust after surgical manipulation of the middle ear and

obstructions caused by mucosal adhesion in patients with

chronic middle ear inflammation.

14,16

Intratympanic steroid injection is one of actively per-

formed procedures also in our institute; however, it is usu-

ally presumed to restore recent hearing loss for those who

were not responded to systemic steroid or in whom sys-

temic steroid is contraindicated, but not for recurrent ver-

tigo. For this reason, we did not seriously consider

intratympanic steroid as an option for intractable MD and

mainly used it for restoring combined acute hearing loss.

Detailed analysis of the patients with hearing

improvement after ITG revealed that two of six patients

experienced hearing loss with aggravation of vertigo just

prior to ITG because ITG usually conducted when the

symptom was aggravated. The fact that all six patients

showed typical low-tone hearing loss suggests that these

hearing changes could be explained by the resolution

and enlargement of hydrops that usually begins at the

apical turn of the cochlea.

20,21

These results also suggest

that the hearing improvement in some cases might be

resulted from transient hearing loss in the proximity of

ITG as the enlargement of hydrops rather than a real

improvement of hearing after ITG.

Two patients progressed to bilateral Menie`re’s dis-

ease after ITG in our study. Previous studies reported

that 5% to 33.3% of unilateral Menie`re’s disease pro-

gresses to bilateral disease,

22–24

and 25% to 30% of bilat-

eral endolymphatic hydrops were found according to a

human temporal bone study.

25,26

A more confusing issue

is that most cases progress to bilateral disease serially

rather than simultaneously and that contralateral dis-

ease begins usually at least 2 to 5 years after the first

manifestation.

Therefore, procedures essentially result-

ing in the ablation of hearing should be performed care-

fully, and ETG could be an alternative to them.

For the possibility of carrying out ELSD as a sal-

vage procedure after the failure of ITG, it seems to be

reasonable to compare ELSD with ETG. Labyrinthec-

tomy or vestibular neurectomy is far more destructive

procedures than ELSD or ETG, which in turn can result

in the ablation of a vestibular reflex. Our results showed

complete control of vertigo (class A) with ETG in five of

seven cases (71.4%). This was superior to that of ELSD

(45.5% up to class A), although it was performed for

failed cases of ITG. Hearing aggravation after ETG (1/7

patients; 14.3%) was slightly higher than ELSD (1/11

patients; 9.1%); however, the hearing level was not a

serious matter because most patients already had more

than 55 dB hearing loss.

CONCLUSION

ITG showed favorable vertigo control (89.5%) and

hearing preservation rate (91.6%). However, 10 (10.5%)

cases still suffered from intractable episodic vertigo, and

six of them were revealed to have failed to achieve suffi-

cient attenuation of vestibular function even after multiple

ITGs. For those who have failed ITG, ETG can be consid-

ered (success rate in this study: 71.4%). Labyrinthectomy

or vestibular neurectomy can be chosen for those who

failed to achieve vertigo control even after ETG.

BIBLIOGRAPHY

1. Schessel D, Minor LB, Nedzelski J. Meniere’s disease and other peripheral

vestibular disorders. In: Cummings CW, Haughey BH, Thomas JR, eds.

Cummings Otolaryngology—Head and Neck Surgery (4

ed.)

Chicago IL:

Mosby; 2004:3209–3253.

2. Boleas-Aguirre MS, Lin FR, La Santina CC, et al. Longitudinal results

with intratympanic dexamethasone in the treatment of Meniere’s dis-

ease.

Otol Neurotol

2008;29:33–38.

3. Santos PM, Hall RA, Snyder JM, et al. Diuretic and diet effect on

Meniere’s disease evaluated by the 1985 Committee on Hearing and

Equilibrium guidelines.

Otolaryngol Head Neck Surg

1993;109:680–689.

Laryngoscope 125: April 2015

Rah et al.: Intractable Menie` re’s Disease