Hideto Niwa

Effect of single-drug treatment on idiopathic sudden sensorineural hearing loss

OBJECTIVES In order to evaluate the effect of a medical administration for the sudden deafness patients, single-drug treatment for idiopathic sudden sensorineural hearing loss (ISSHL) was assessed at multi-centers participating in the Acute Severe Hearing Loss Study Group sponsored by the Ministry of Health, Labor and Welfare of Japan. METHODS The subjects consisted of ISSHL patients who were (1) 20 years of age or older, (2) diagnosed within 2 weeks after the onset of hearing loss, (3) showing a mean hearing level of 40-90 dB at five frequencies from 250 to 4000 Hz, (4) previously untreated, and (5) with normal for age in hearing of the opposite ear. The drugs used in this study were ATP, alprostadil, hydrocortisone and amidotrizoate, which were administered intravenously, and beraprost sodium and betamethasone, which were given orally. Two drugs were assigned to each center, one of which was selected according to the code hidden in envelopes and administered for 1 week. The treatment after the single-drug administration was conducted at the discretion of each center. The hearing gain and recovery rate at 1 week after the initiation of single-drug treatment and at 1 month or over when the hearing level was fixed, were evaluated based on the criteria for hearing recovery prepared by the Acute Severe Hearing Loss Study Group. RESULTS There was no statistically significant difference in the recovery rate among drugs either at 1 week after the initiation of single-drug treatment or at the time of fixed hearing level. At the time when the hearing level was fixed, a statistically significant difference in the complete recovery rate was detected only between amidotrizoate and beraprost sodium. CONCLUSION From these results, we could not find any specific drugs recommended for ISSNHL. In evaluating the effect of the drugs, however, several problems in the clinical trial for ISSHL should be considered.

The effect of furosemide on evoked otoacoustic emissions in guinea pigs

After recording transiently evoked otoacoustic emissions (TEOAEs) to a click stimulus in guinea pigs by using the IL088 which was developed by Bray and Kemp (1987) for easy recording and analysis of TEOAE, the changes after intravenous administration of furosemide (30 mg/kg or 50 mg/kg) were examined. The wave of the TEOAE could be detected from 20 of 24 ears (83%). After the i.v. injection of furosemide (30 mg/kg), TEOAE powers (total echo power and highest peak power in FFT pictures) decreased quickly and showed minimum values after 5-10 min. Then they increased rapidly and recovered normally within 60 min after injection. However, no ears showed TEOAEs during the 5- to 10-min period following the injection of the 50-mg/kg dose of furosemide. They then recovered slowly as compared with the group treated with the lower dose of furosemide (30 mg/kg). These changes are similar to those of the endocochlear potential (EP) after furosemide injection. These data support the notion that the EP can contribute to the mechanism of TEOAE generation.

HLA associations in otosclerosis in Japanese patients

Otosclerosis is a disease of the otic capsule that is caused by abnormal resorption and redeposition of bony tissue. Sixty-two unrelated Japanese patients exhibiting clinical otosclerosis were typed for HLA-A, -B,-C antigens. Twenty-one of the patients were also typed for DR antigens. The frequency of HLA-Aw33 was significantly higher in otosclerosis patients than in the control group (24.2% vs 9.5%). This finding suggests that the presence of HLA-Aw33 antigens may be related to an increased susceptibility to otosclerosis or to its clinical outcome.

Spectral analysis of airflow sounds in patent versus occluded tracheostomy tubes: a pilot study in tracheostomized adult patients.

Cannula occlusion is a life‐threatening postoperative complication of tracheostomy. Current management largely relies on nursing care for prevention of fatalities because no proven mechanical, machine‐based support monitoring exists. The objective of this paper was to address the problem of monitoring the state of cannula patency, based on analysis of airflow acoustic spectral patterns in tracheostomized adult patients in the patent and partially occluded cannula. Tracheal airflow sounds were picked up via a condenser microphone air‐coupled to the skin just below the tracheal stoma. Signal output from Mic was amplified, high‐pass filtered, digital tape‐recorded, and analyzed on a mainframe computer. Although airflow frequencies for patent cannulae were predominantly low‐pitched (0.1 to 0.3 kHz), occluded tubes had discrete high‐pitched spectral peaks (1.3 to 1.6 kHz). These results suggest that frequency analysis of airflow sounds can identify a change in the status of cannula patency.

PO2 Levels in Middle Ear Effusions and Middle Ear Mucosa

We measured PO2 values in mucoid and serous middle ear effusions (M-MEE, S-MEE) and in the middle ear mucosa of patients with otitis media with effusion (OME) and compared these values with those obtained from patients with middle ear barotrauma (MEBT). The mean and S.D. values of PO2 in M-MEE, S-MEE and MEBT effusions were 28.9 +/- 11.3, 31.5 +/- 9.5 and 37.0 +/- 15.4 mmHg, respectively; the mean and S.D. values in mucosa were 27.1 +/- 11.9, 27.0 +/- 13.2 and 32.5 +/- 1.0 mmHg, respectively. In health, PO2 values in middle ear mucosa are regulated by its blood supply, oxygen solubility in blood and the blood-to-cavity partial pressure gradient of the gas. When the Eustachian tube (ET) function is severely impaired, PO2 values in the middle ear air cavity depend on the mucosal condition, though some studies have shown a lack of relationship between ET function and PO2 values. Our results show that PO2 values in MEBT are consistently higher than in OME, suggesting that the attributable factor could be a better ET function in MEBT.

Evaluation of Clearance Function of the Eustachian Tube by Sequential Contrast CT

Comparisons of Eustachian tube (ET) functions studied by sequential contrast computerized tomography (CT) and by tubotympanic aerodynamics (TTAG) were made. ET clearance function was assessed by the shape of the cartilaginous portion before, during and at the end of swallowing; ventilatory function was studied by TTAG. ET clarity, real-time dynamics and resolution were all better when observed with sequential CT. Contrast medium was instilled into the middle ear via a drumhead perforation and 1 scan/sec taken during swallowing. We classified ET function based on the presence or absence of a) movement of the cartilaginous portion, and b) contrast medium in the ET as i) movement present, contrast medium seen in ET: ii) movement absent, contrast medium present in ET; and iii) movement present, no contrast medium in the ET. Ventilatory and clearance functions did not parallel one another, attributable to some mechanical, differences between the two functions.

Subcortical Hearing Disorders: Report of 2 Cases

We report two cases of hearing disorder resulting from bilateral subcortical lesions. One patient developed complete deafness, and the other patient initially developed complete deafness which resolved into auditory agnosia. The lesions were demonstrated radiologically to be bilaterally subcortical and unaccompanied by cortical damage; auditory electrophysiological examinations confirmed intact peripheral and brainstem pathways.

Factors Affecting Improvement of Hearing After Stapes Surgery

Presently, stapedectomy and stapedotomy are common techniques for improving hearing defects secondary to otosclerosis. Ninety-two consecutive cases with otosclerosis were analyzed on the postoperative hearing gain. The degree of postoperative hearing gain was affected by many factors, such as sex, age, preoperative bone conduction at high frequencies, and preoperative A-B gap at speech frequencies. The age of patients did not affect the postoperative hearing gain, while sex, preoperative bone conduction, and preoperative A-B gap at speech frequencies influenced postoperative hearing gain.

A Case of Allergic Aspergillus Sinusitis with Acute Onset

Reports of allergic aspergillus sinusitis have increased in recent years and diagnostic criteria have also come to be established, yet this disease remains a rare disorder. The disorder is generally reported to follow a chronic course. Here we report a case of allergic aspergillus sinusitis with a short morbid term of 3 weeks.

Ossifying Fibroma of the Temporal Bone.

A 17-year-old male with partial hearing loss and otorrhea was diagnosed as having ossifying fibroma from the findings of plain skull roentogenograms, CT scan, bone scintigrapy (99mTc), selective carotid angiography, and biopsy. The tumor was removed by curettage, and the hearing improved by tympanoplasty.Ossifying fibroma is a rare fibro-osseous tumor, usually found in the maxilla or mandible. It is seldom seen in the temporal bone; only 5 such cases have been reported. The clinical, radiological, and pathological characteristics of the disease are discussed with some reference to the literature.