Shin Aso

A CLINICAL STUDY OF ELECTROCOCHLEOGRAPHY IN MENIERE'S DISEASE

Electrocochleography (ECochG) of 168 ears with definite Menieres disease was studied. The results were compared with recordings from 29 normal ears and 444 ears with other types of sensorineural hearing loss. It is shown that the SP/AP ratio is much more useful than SP amplitude for detecting endolymphatic hydrops. There was little difference in the mean values of SP/AP from those proposed by many other investigators; the mean values all being near 0.25. From 0.30 to 0.40 of SP/AP was considered adequate as the upper limit. Following intravenous administration of glycerol, a significant decrease in SP/AP was found in 21 Menieres ears. However, there was no change of SP/AP after oral administration of glycerol and isosorbide. This difference may be due to the fact that a larger oral than intravenous administration is necessary to affect SP/AP. Although a postoperative decrease of 10% or more in SP/AP was observed in 5 patients, 10 patients followed up for 2 years or more after surgery did not show a statistically significant change of SP/AP and pure tone threshold. ECochG should be repeatedly recorded to be useful as a monitor for the presence of hydrops. It is discussed whether biochemical or mechanical changes in endolymph may cause a decrease in SP/AP after the use of dehydrating agents and endolymphatic sac surgery.

Prognosis of low-tone sudden deafness – does it inevitably progress to Meniere's disease?

Conclusion. We conclude that not all low-tone sudden deafness (SD) patients suffered from endolymphatic hydrops even if they had vertigo attack at the onset and that electrocochleography (ECochG) was a useful prognostic tool. Objectives. To investigate whether low-tone SD was a precursor of Menieres disease and whether patients with low-tone SD suffered from endolymphatic hydrops. Patients and methods. This was a retrospective case review in the university hospital. A total of 184 patients with low-tone SD were divided into two groups with single and recurrent episodes. The progress, follow-up audiograms, and ECochG results of the patients were reviewed and compared with those of patients with high-tone SD and Menieres disease. Results. In all, 83 of 177 patients with low-tone SD unaccompanied by vertigo had recurrent hearing loss; 15 of the 83 developed vertiginous attacks. The remaining 94 patients had a single episode. Three of the seven patients with low-tone SD accompanied by vertigo had recurrent hearing loss; two of the three were subsequently confirmed to have Menieres disease. The other four had a single episode. No difference in rate of progress from SD to Menieres disease was observed among the low-tone and the high-tone SD groups. The average -SP/AP of each group with a single episode is smaller than that of other groups with recurrent episodes and Menieres disease.

Prediction of progression from atypical to definite Ménière's disease using electrocochleography and glycerol and furosemide tests.

Objective--To investigate whether electrocochleography (ECochG) and glycerol and furosemide tests could predict progression from atypical to definite Ménières disease (MD). Material and methods--ECochG and glycerol and furosemide tests were performed in 1569 patients with various cochleovestibular diseases, including definite MD, atypical MD, syphilitic labyrinthitis, delayed endolymphatic hydrops, sudden hearing loss, cochleovestibulopathy and sensorineural hearing loss. Patients with atypical MD were divided into five categories based on their symptoms. Results--A total of 115/118 patients (97%) with definite MD who underwent all 3 tests showed a positive result in at least 1 test. Ninety-nine patients who did not satisfy the diagnostic criteria of definite MD but had vertigo and/or hearing loss at the first visit subsequently progressed to definite MD. It was retrospectively found that 92% of patients showed at least 1 positive finding in these 3 tests at the initial stage. In those patients who showed a negative test result in either ECochG or the glycerol test, the possibility of progression to definite MD was low. Conclusion--The combination of ECochG and the glycerol and furosemide tests was helpful in diagnosing endolymphatic hydrops (ELH). ECochG and the glycerol test were effective tools for predicting the progression to definite MD in patients with atypical MD, sudden hearing loss and other cochleovestibular diseases. Our test results also indicated that the pathological state of atypical MD included both non-ELH and ELH.

Ménière's disease and delayed endolymphatic hydrops in children.

In order to study the characteristics of pediatric patients (≤ 15 years at onset) with endolymphatic hydrops disorders, we selected 5 patients with Ménières disease (MD) and 3 patients with delayed endolymphatic hydrops (DEH) from 7418 patients who had visited the Neurotological Clinic of the Toyama Medical and Pharmaceutical University Hospital between 1979 and 1999. Clinical features were characterized as follows: (i) pediatric MD patients were rare, comprising ≈ 1.5% of all the 337 MD patients in the sample; (ii) a fluctuating hearing loss, strong positive response in glycerol test, high SP/AP amplitude ratio in electrocochleography and moderate positive response in furosemide vestibulo-ocular reflex test were recorded; (iii) in 2 of the 5 pediatric MD patients, vertiginous attacks had persisted for a long period and they had undergone surgical procedures (sac operation and vestibular neurectomy); and (iv) the ipsilateral type of DEH was observed in 2/3 children, and contralateral DEH in 1/3.In order to study the characteristics of pediatric patients (< or = 15 years at onset) with endolymphatic hydrops disorders, we selected 5 patients with Ménières disease (MD) and 3 patients with delayed endolymphatic hydrops (DEH) from 7418 patients who had visited the Neurotological Clinic of the Toyama Medical and Pharmaceutical University Hospital between 1979 and 1999. Clinical features were characterized as follows: (i) pediatric MD patients were rare, comprising approximately 1.5% of all the 337 MD patients in the sample; (ii) a fluctuating hearing loss, strong positive response in glycerol test, high SP/AP amplitude ratio in electrocochleography and moderate positive response in furosemide vestibulo-ocular reflex test were recorded; (iii) in 2 of the 5 pediatric MD patients, vertiginous attacks had persisted for a long period and they had undergone surgical procedures (sac operation and vestibular neurectomy); and (iv) the ipsilateral type of DEH was observed in 2/3 children, and contralateral DEH in 1/3.

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 Menières 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.

A case of Behçet's disease with otologic symptoms.

Behçets disease is generally known as an autoimmune disease. We report a case of Behçets disease who had fluctuating hearing loss, tinnitus and dizziness. A 37-year-old woman had bilateral hearing loss in low audiometric frequencies. Audiological and vestibular examinations revealed an inner ear lesion. The patient had an enlarged negative summation potential in the electrocochleogram and a positive glycerol test, which suggested endolymphatic hydrops. The pathological characteristic of Behçets disease is thought to be vasculitis. So this case suggests an association of autoimmune vasculitis with endolymphatic hydrops.

Changes in Auditory Evoked Responses During Intravenous Lidocaine

Auditory evoked responses in 21 cases with tinnitus were recorded before and after the administration of intravenous lidocaine. A dosage of 1 mg/kg body weight was diluted with 20% glucose (20 ml) and administered intravenously over a one-min period. The loudness of tinnitus was evaluated during electrocochleography (ECochG) or auditory brain-stem response (ABR) recordings using a score between 0 and 11. The stimulus sound was a tone burst in a frequency that corresponded to the pitch of tinnitus. AP latency on ECochG and the inter peak latency (IPL) of wave I-III and wave III-V on ABR were prolonged momentarily and tinnitus was reduced. These findings reveal that the sites of action for lidocaine are both the inner ear and the brain-stem.

Clinical Study of the Role of Melanocytes in the Inner Ear of Patients with Harada’s Disease

Haradas disease is an autoimmune disorder involving melanocytes. Twenty patients with Haradas disease underwent otoneurological examination to investigate the inner ear involvement in Haradas disease and the function of the melanocytes in the inner ear. All 20 exhibited clinical and/or laboratory abnormal inner ear findings. The incidence of inner ear involvement in Haradas disease is very high. The melanocytes in the inner ear play important roles in both auditory and equilibrium function.

Influence of a Cold Front upon the Onset of Meniere's Disease in Toyama, Japan

In order to clarify the influence of a cold front (CF) upon the onset of Meniéres disease (MD), major CFs were defined by meteorological observations, and the influence of CFs on MD was evaluated by using the time n method. From our preliminary study it was seen that the onset of MD had its highest incidence exactly on days where a CF passed by. Out of the patients with MD, sudden deafness (SD) and Bells palsy (BP) who visited our neurotological clinic of the Toyama Medical and Pharmaceutical University from 1987 to 1992, 67 MD patients, 70 SD patients and 70 BP patients could clearly define the date of the onset of their disease, and were therefore selected for this epidemiological study. Thirty-six our of the 67 MD patients had the first attack on the day when a CF passed by or on the next day. The results obtained from these studies were as follows. i) The onset of MD was influenced by the passing of a CF, and this influence was more specific in MD than in SD or BP. ii) In the 36 CF influence MD patients, the majority were over the forty years, and their hearing level was worse than that of the other 31 MD patients during the observation periods.

The Intravenously Administered Glycerol Test

Three different methods of performing the glycerol dehydration test were evaluated. Method one involved the oral administration of 50 g of 50% glycerol solution; method two was the intravenous administration of 500 ml of 10% glycerol in saline with 5% fructose; and method three involved the administration of 200 ml of the same solution. It was found that intravenous administration was safe and did not give any unpleasant side effects. Both intravenously administered methods appeared to give similar rates of positive diagnosis for Menières disease.