HSC Section 8_April 2017

American Academy of Otolaryngology–Head and Neck Surgery

(AAO–HNS).

Eighty-nine patients of definite MD group and seventeen

patients of secondary EH group received additional interven-

tions such as ITG, endolymphatic sac decompression (ELSD),

and application of the Meniett device after the failure of medi-

cal treatment. They were followed up for at least 2 years (range:

2.1–7.5 years), and their treatment flow and outcomes were

analyzed. A total of 21 patients were excluded from analysis

due to the inadequate follow up or data collection. This study

was approved by the Seoul National University Bundang Hospi-

tal Institutional Review Board (B-1310/222-102).

Selection of the Treatment Options

For intractable patients, next treatment options were dis-

cussed with patients and considered mainly depending on the

patient’s hearing status. ELSD was suggested if the patient’s

pure tone average was better than 40 dB by averaging the 0.5,

1, 2, and 3 kHz; and ITG was recommended if it was not. In

some patients, ITG was not feasible due to chronic otitis media,

and gentamicin was applied around the round window and oval

window after removing of thickened mucosa during a tympano-

mastoidectomy. ITG was basically considered for the patients

whose vertigo was not controlled by medical treatment for more

than 3 to 6 months and had worse than 40 dB hearing thresh-

olds. However, ITG was also performed for some patients under

serious risk of head trauma due to recurrent Tumarkin crises,

although they had better than 40 dB hearing level.

Protocols for the Intratympanic Injection of

Gentamicin

Gentamicin was administered as described below. Patients

were lying down in supine position with the head elevated up to

30 degrees and turned to the other side at 45 degrees. The ear

canal and tympanic membrane were anesthetized, and two

holes were made with a 26-G needle at anterosuperior area of

tympanic membrane. About 0.3 to 0.5 mL of gentamicin solu-

tion (gentamicin sulfate, 40 mg/mL) was administered into the

middle ear cavity. Patients were advised to remain in the same

position at least 20 minutes and to avoid swallowing or

yawning.

Characteristics of dizziness were asked, and an office

exam was conducted to evaluate vestibular status at 2 weeks

and 4 weeks after injection to determine the efficacy of the pre-

vious administration. If typical paralytic nystagmus to the con-

tralateral side (spontaneous nystagmus, post-head shaking

nystagmus, vibration-induced nystagmus) or laboratory evi-

dence of attenuation (or ablation) of remaining vestibular func-

tion on a caloric test was evident, the injection was thought to

be successful and no additional administration was considered.

However, if the patients experienced episodic vertigo spells

instead of crescendo–decrescendo type persistent dizziness or

there was no evidence of attenuation of vestibular function,

injections were repeated until signs of ipsilateral vestibular

hypofunction were more evident.

Analysis of Changes in Hearing and Vertigo

All hearing and vertigo data were analyzed according to

the 1995 AAO–HNS guideline.

Vertigo was assessed as the

average number of definite spells per month for the 6 month

periods prior to ITG and compared with that assessed between

18 to 24 months after ITG. Hearing level was assessed at the

same time periods by averaging the 0.5, 1, 2, and 3 kHz pure

tone thresholds. We compared changes in hearing threshold and

frequency of vertigo after ITG.

Analysis of Problems After ITG

For the patients who were refractory even after ITG,

exploratory tympanotomy and gentamicin application (ETG),

labyrinthectomy, and vestibular neurectomy were then consid-

ered. Among them, ETG was primarily considered the next step

to rule out any anatomical problem that might obscure the pas-

sage of gentamicin into the inner ear for those whose vestibular

function was not ablated sufficiently by ITG. We applied ETG

when the patients showed no improvement after three or four

attempts of ITG. That was determined on the basis of our find-

ings that most cases with successful improvement of vertigo

improved after only two (75%) or three (86%) rounds of ITG and

that the chance of failed control of vertigo increased with multi-

ple injections (odds ratio

11.8;

0.005, Fischer’s exact test).

Failure due to insufficient attenuation of vestibular function or

recurrent dangerous event, such as Tumarkin crises even after

ITG, was also considered. Labyrinthectomy and vestibular neu-

rectomy were considered if symptoms had not improved even

after ETG. We analyzed the outcomes of the treatment options

used and their problems. Long-term time course of hearing loss

were analyzed to clarify the cause of hearing aggravation after

ITG. Bilateral progression of MD after ITG and its problems

were analyzed.

RESULTS

Patients’ Characteristics and Applied Treatment

Options

The average age of the total 95 patients was 58

years old (range: 28–75 years old; definite MD group:

57.5 years old, secondary EH group: 60.1 years old);

there were 38 male patients (48.7%) in the definite MD

group and eight male patients (47.0%) in the secondary

EH group. The patients experienced 7.1 vertigo attacks

in a month for the definite MD group and 5.4 vertigo

attacks in a month for the secondary EH group when

averaged for 6 months prior to ITG. Vestibular function

on bithermal caloric test before injection was decreased

in 14 patients (82.4%) of the secondary EH group and in

53 patients (67.9%) of the definite MD group (

0.38,

Fischer’s exact test). Tumarkin attacks were present in

five cases (29.4%) of the secondary EH group and in 15

patients (19.2%) of the definite MD group (

0.34,

Fischer’s exact test).

Overall Treatment Flow

Of the 667 patients with definite MD, 578 (86.7%)

patients showed improvements with lifestyle modifica-

tion or medical treatment. Additional interventions such

as ITG, ELSD, and application of the Meniett device

were performed in 89 (13.3%) patients due to intractable

vertigo, and ITG (78 patients, 87.6%) occupied the

majority among them (Fig. 1). The patients group who

received ITG included four patients whose vertigo attack

was not controlled, even after ELSD treatment. ELSD

achieved 45.5% (5 of 11 patients) of class A and B vertigo

control and showed 9.1% (1 of 11 patients) of more than

10 dB hearing loss after surgery. Although treatments

Laryngoscope 125: April 2015

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