Sensorineural hearing loss induced by radiation as a late effect: five cases followed by audiogram.

OBJECTIVE: We studied the progression of the late radiation-induced sensorineural hearing loss (SNHL) to discuss the pathological mechanism responsible for the progression with referring to past reports. METHODS: Five cases were selected among the SNHL cases diagnosed at the Department of Otolaryngology. Hokkaido University. All the cases were followed up with audiograms. RESULTS: All of the five cases showed gradual progression of SNHL, which developed mostly 1 2 years after irradiation for brain tumors. Two of them showed rapid progression from time to time with sudden onset in their clinical courses. All the patients were resistant to any medication such as steroid, vitamin B12 or cerebral circulation activators. CONCLUSION: Two patterns of progressions of radiation-induced hearing loss were observed. Both of them were considered to be explainable by ischemic changes of the vessels as reported earlier. Since there is no effective treatment for radiation-induced SNHL, it is most important to enlighten clinicians in general on this disease.

Preserved otoacoustic emission in a child with a profound unilateral sensorineural hearing loss.

We report a case of profound unilateral sensorineural hearing loss with good response of otoacoustic emission. The patient was a 5-year-old boy. who was diagnosed to have unilateral hearing impairment on pure tone audiometry at the first visit. The affected ear showed the absence of auditory brainstem response; however, its transiently evoked otoacoutic emission and distortion product otoacoustic emission were considered to be normal. These findings indicated that the outer hair cell of cochlea was not impaired and that the impairment should be localized between inner hair cells, primary afferent fiber or its synapses, spiral ganglion of the cochlea and acoustic fiber, or at a combination of these areas. That is, evaluation of otoacoustic emission was useful in determining the region of impairment in sensorineural hearing loss. Further follow-up will be necessary to differentiate the present case from auditory neuropathy.

An anti-mumps IgM antibody level in the serum of idiopathic sudden sensorineural hearing loss.

PURPOSE: Measurement of anti-IgM antibody for mumps enables us to diagnose silent mumps infection. From the viewpoint of prophylactic medicine, we examined the incidence of silent mumps infection in idiopathic sudden sensorineural hearing loss (ISSNHL) by measurement of anti-mumps IgM antibody. MATERIALS AND METHODS: Serum level of anti-mumps IgM antibody was evaluated by EIA method in 69 ISSNHL cases. RESULTS: Of the 69 serum samples examined, five samples were positive, two samples were regarded as quasi-positive and other samples were negative for anti-mumps IgM antibody. The positive rate was 7.2% (5/69). The relationship of anti-mumps IgM and IgG antibody was also described. CONCLUSIONS: From the measurement of anti-IgM antibody for mumps, it was possible to diagnose silent mumps infection in ISSNHL. The positive rate of anti-IgM antibody in ISSNHL was 7.2% suggesting that the silent mumps infection could be considered as one of the causative factors of ISSNHL even though its incidence is not so high. Since mumps often occurs without clinical symptoms, it is still considered to be one of the important causes of profound hearing loss. From the viewpoint of prophylaxis of profound hearing loss and deafness, we should understand the situation of virus epidemiology and vaccination.

Effects of spontaneous otoacoustic emissions on distortion product otoacoustic emission.

OBJECTIVE: It has been reported that spontaneous otoacoustic emission (SOAE) can prolong the responses or increase the echo power of transiently evoked otoacoustic emission (TEOAE), yet the effects of SOAE on distortion product otoacoustic emission (DPOAE) have been studied less thoroughly. As most of the previous studies have not paid attention to the patient's age, sex and hearing level, they have not reflected possible effects of those factors. We studied the effects of SOAE specifically on DPOAE in the following subjects. SUBJECTS AND METHODS: The subjects were all females ranging in age from 19 to 24 (average: 21.4) and the 78 ears had a hearing threshold under 15 dB for 1.2, and 4 kHz on pure-tone hearing test. IL088 (Otodynamics) was used for measurement of SOAE and IL092 (Otodynamics) for DPOAE. SOAEs were measured by time-averaging over 100 of the responses, of which those showing a clear peak 3 dB above the noise floor and being reproducible were considered as SOAE-positive. In all the ears. DPOAE responses were measured at L1 = L2 = 70 dB, and in 42 ears also at L1 = L2 = 60 dB and L1/L2 = 60/50 dB. The subjected ears were grouped into two by the presence or the absence of SOAE, and DPOAE amplitudes of 1, 2, and 4 kHz were compared. respectively. RESULTS: Of the total, 39 ears were SOAE-positive and 39 SOAE-negative. Statistically no significant difference was observed in the average hearing level between the SOAE-positive and SOAE-negative groups. The hearing levels did not significantly differ in the frequencies of 1, 2. and 4 kHz, respectively, indicating that influence of the hearing level on DPOAE could be excludable. DPOAE amplitudes at L1 = L2 = 70 dB in the frequencies of 1, 2, and 4 kHz were higher in the SOAE-positive group than in the SOAE-negative group. And DPOAE amplitudes were also higher in SOAE-positive group at L1 = L2 = 60 dB and L1/L2 = 60/50 dB in the frequency of 1.2, and 4 kHz, but significant differences were observed only in the frequencies of 4 kHz. By grouping the ears by the number of SOAE. we revealed the tendency that the larger the number of SOAE, the higher the DPOAE amplitudes. CONCLUSIONS: We evidenced that SOAE has significant effects on DPOAE responses. In clinical application of DPOAE measurement, therefore, the effects should be seriously taken into account.

[Utility of OAE screener (GSI 70) for the evaluation of distortion product otoacoustic emissions].

The purpose of this study was to investigate the ability of the OAE screener GSI 70 to evaluate of cochlea function in neonates, infants and adults. Distortion product otoacoustic emissions (DPOAEs) were measured using the GSI 70 DPOAE Analyzer and evaluated in 123 human ears between December 1999 and June 2000. We performed the following four general clinical tests to determine the reliability of the GSI 70: 1) comparison of DPOAE levels measured using the ILO 92 and the GSI 70 in 55 adult ears, 2) comparison of DPOAE levels measured using the GSI 70 and hearing levels in 55 adult ears, 3) comparison of DPOAE levels measured using the GSI 70 and ABR levels in 45 neonate and infant ears, and 4) evaluation of the utility of DPOAE measurements obtained using the GSI 70 in functional deafness cases. The following results were obtained: 1) DPOAE levels measured with the ILO 92 and the GSI 70 were closely correlated (correlation coefficient, 0.773 at 2 kHz and 0.813 at 4 kHz). 2) The sensitivity of the GSI 70 in adult ears confirmed to have normal hearing was 80% at 2 kHz and 100% at 4 kHz; the specificity of hearing-impaired ears was 94% at 2 kHz and 94% at 4 kHz. 3) The sensitivity of the GSI 70 in normal neonate and infant ears with normal hearing was 100% at 2 kHz and 100% at 4 kHz; the specificity of hearing-impaired neonate and infant ears was 97% at 2 kHz and 94% at 4 kHz. 4) All of the functionally deaf ears showed excellent DPOAE responses. Examinations using the GSI 70 DPOAE analyzer were very easy and fast. Also, the results were highly reliable, with the exception of one adult who was classified as having normal hearing in an out-of-scale hearing level at 2 kHz. We suggest that specific criteria be established for the clinical usage of the GSI 70 in performing objective hearing evaluations.

[Influence of spontaneous otoacoustic emission (SOAE) on transiently evoked otoacoustic emission (TEOAE)].

The literature has reports on the influence of spontaneous otoacoustic emission (SOAE) on transiently evoked otoacoustic emission (TEOAE), but most do not take factors such as age, gender, and hearing level into consideration. We focused on these conditions. Subjects were 78 women with normal hearing aged 19 to 24 years (mean = 21.4). All had pure tone thresholds of 15 dB HL or better at 1 kHz, 2 kHz, and 4 kHz. ILO88 was used to record TEOAE and SOAE. Echo power (EP) and reproducibility (Repro) were compared between groups with and without SOAE. No significant audiometric difference was seen between groups. Total echo power (TEP) and whole reproducibility (WR) were significantly greater in the group having SOAE, consistent with previous reports (p < 0.01). EP and Repro classified by frequency bands were also significantly greater in the group having SOAE at 1 kHz to 4 kHz. Subjects were divided based on the number of SOAE and the above parameters compared. We found that as the SOAE number increased, EP and Repro increased. In conclusion, the existence of SOAE influences TEOAE parameters and must be taken into account during clinical testing.

[Transient evoked otoacoustic emission measurement in infants].

Transient evoked otoacoustic emissions (TEOAEs) were measured and evaluated in 194 ears of 101 subjects under 4 years old who were suspected of hearing loss, using a ILO88 Otoacoustic Emission Analyzer, to study the basic characteristics of this measure and its utility for hearing screening. The mean time necessary to record TEOAEs in both ears was short, about 3 minutes. In 58 ears judged as normal hearing within 30 dB in ABR, TEOAE levels in infants aged less than 2 months were significantly higher than in those aged more than 1 year, especially in the high frequency bands (4-kHz and 5-kHz bands). One case which had been judged as bilateral moderate-to-profound hearing impairment in initial ABR testing showed good responses in TEOAEs, indicating normal cochlear function, and obvious wave Vs in follow-up ABRs recorded at 30 dB nHL confirmed normal auditory function. Therefore, in a case like this one, suspected of retardation in brain stem maturation, TEOAE is more useful than ABR as a hearing screening technique. Since external and middle-ear factors caused poor TEOAE responses in some cases which had been judged as normal hearing by ABR. TEOAE seems to be more sensitive in detecting external and middle ear problems than ABR. Moreover, TEOAE measurement of infants was easy and noninvasive. We conclude that TEOAE is an excellent tool for screening auditory function in infants.

[Studies of the evaluation of cochlea function with distortion product otoacoustic emission].

Distortion product otoacoustic emission (DPOAE) is one of the acoustic responses derived from the inner ears and it has very sharp frequency specificities. The purpose of this study is to investigate the utility of DPOAE as a method for evaluating human cochlea functions. The whole subjects of this study were 414 ears with inner ear hearing loss, 278 ears with normal hearing, 113 ears of neonates, 62 ears of the patients who were administered cisplatin, and 15 ears with functional hearing loss. At first, 5 studies described below were performed to examine the characters and reliability of DPOAE as a clinical test: 1) The average DPOAE-gram of normal hearing ears. 2) The comparison between DPOAE levels and hearing levels. 3) The reproducibility of DPOAE on the different examinations in the same subjects. 4) The influences of respiratory noises on DPOAE levels. 5) The detection of fine cochlea damages using DPOAE which can not be detected by pure tone audiometry. Then the following 2 clinical studies were performed: 6) The utility of DPOAE in neonates and children. 7) The utility of DPOAE in functional deafness cases. From these studies, the following characters of DPOAE were confirmed. Since DPOAE levels have correlations with hearing levels at the same frequencies, normal hearing could be determined by the DPOAE level. DPOAE is useful for following chronological changes in hearing because of its reproducibility in a same subject at different times. The early and fine damages on the cochlea that could not be detected by conventional pure tone audiometry might be detected by DPOAE in some cases. Considering these results, it was concluded that DPOAE could be a new objective hearing test which would help the conventional examinations. Especially in infants who can't be examined with pure tone audiometry, DPOAE is thought to be a very useful examination.

[Relationship between distortion product otoacoustic emissions and pure tone thresholds in normal and hearing-impaired ears].

To establish clinical criteria for distortion product otoacoustic emissions (DPOAEs) in order to distinguish normal-hearing from hearing-impaired ears, DPOAEs were measured and evaluated in 325 normal and 291 cochlear-impaired human ears using an ILO92 Otoacoustic Emission Analyzer. The background noise level was too variational in each individual ear to ignore in DPOAE measurements. Therefore, the value of the difference between the DPOAE amplitude and the background noise level (DPOAE noise) was calculated and compared with the pure tone threshold at 1 kHz, 2 kHz and 4 kHz. It was difficult, however, to precisely separate normal-hearing and hearing impaired ears with DPOAE noise values because many normal ears presented small amplitudes of DPOAEs and some impaired ears showed high amplitudes. Therefore, cumulative distributions of sensitivity (normal hearing ears identified as normal hearing) and specificity (hearing impaired ears identified as hearing impaired) were constructed and used to calculate a cut off point for DPOAE-noise in order to separate normal hearing from hearing impaired ears. It is considered that the cut-off points (DPOAE noise values of 7.3 dB at 1 kHz, 10.3 dB at 2 kHz and 16.1 dB at 4 kHz) at which the false alarm rates (1 specificity: the rate of hearing impaired ears incorrectly identified as normal hearing) correspond to 5% can be useful for clinical evaluation of DPOAEs.

[Otoacoustic emissions of full-term and preterm neonates].

Transiently evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), and spontaneous otoacoustic emission (SOAE) were measured in 45 full-term neonates (68 ears) and 12 preterm neonates (20 ears) with ILO88 & 92. Measurements were performed in the nursery of the obstetrics ward or NICU (not sound proof room) under natural sleeping condition after nursing. No sedating agent was used. TEOAEs were rated "good response" in 61 (89.7%) of 68 full-term neonate ears. DPOAEs were rated "good response" in 40 (71.4%) of 56 full-term neonate ears. SOAEs were detectable in 25 (62.5%) of 40 full-term neonate ears. Considering the high positive rate of TEOAE in full-term neonates and the easy and noninvasive method of measurement, we concluded that TEOAE is useful for auditory screening in neonates. There was failure to detect TEOAEs in 7 ears and the measurements were all performed within 6 days after birth. Some reports claim that residual amnion in the external auditory canal or the middle ear in the first few days after birth causes slight hearing loss. Thus, we expected that making the measurements more than 7 days after birth might yield higher "good response" rates. We sometimes found that the Total Echo Powers of TEOAEs were reduced by the poor condition of the ear probe. Thus, we must be very careful in regard to this technical problem in order to perform accurate examinations. Because of its lower "good response" rate, DPOAE was not as useful for screening as TEOAE. Because of the movements or respiratory noises of the newborn infants, it was hard to detect reliable DPOAEs, particularly in the low frequency range. On the other hand, because of its frequency specificity, particurally at high frequencies, DPOAE will be useful for detecting the partial hearing impairment such as congenital high-tone hearing impairment. It would be difficult to use SOAE as a clinical test. Because it is not an evoked response, its mechanism of generation is not well understood. We expect that following longitudinal changes in SOAE in neonates may yield some information about it. We measured mainly TEOAE in preterm neonates because we had to complete the measurements as soon as possible. High Total Echo Powers of TEOAEs were recorded in most infants over 38 weeks of PCA (post conceptional age). The earliest case showed reliable TEOAE at 35 weeks PCA. In most cases that could be measured twice on different days, the Total Echo Powers of TEOAE, were higher in the second time. We therefore concluded that TEOAE might serve as an examination for monitoring the maturation of preterm neonate hearing.

[Clinical study of subglottic carcinoma].

Recently, therapy for laryngeal carcinoma has been becoming established, particularly in the early stage. The prognosis of laryngeal carcinoma is said to be better than that of other head and neck carcinomas. Laryngeal carcinoma is divided into 3 subtypes, supraglottic, glottic and subglottic, according to origin. We analyzed the subglottic carcinomas diagnosed and treated in our department between 1972 and 1990. During that period we treated 515 cases of laryngeal carcinoma, 204 cases of the supraglottic type, 284 cases of the glottic type, and 27 cases (5.2%) of the subglottic type. The 5-year survival rate in subglottic carcinoma was 44% (T1: 83%, T2:55%, T3: 17%, T4: 0%), worse than in the other types of laryngeal carcinoma. We think that there were 2 main reasons for the worse prognosis. The first was their high rate of local recurrence after radiation therapy particularly in the early stage. Although 15 T1 and T2 patients who received full dose (65Gy) radiotherapy had a complete response, 8 patients developed local recurrence. The results of the salvage operation were good in T1 cases, but were followed by death because of metastasis or second recurrence in 2 of the 3 T2 patients. The second reason for the worse prognosis appeared to be metastasis in the advanced cases. Five (50%) T3 and T4 patients developed metastasis to the lung, mediastinum and cervical lymph nodes, resulting in death. Thus, we believe that the main therapy for subglottic carcinoma, except T1, should be surgery to obtain a better outcome, and that adjuvant chemotherapy after irradiation or neck (paratracheal) dissection with total laryngectomy should be performed in advanced cases.

Chromium-induced carcinoma in the nasal region. A report of four cases.

The carcinogenicity of chromium is well established in chromium-induced lung cancer. As of yet, however, there have been only few reports of head-and-neck cancer induced by chromium. We report four cases of carcinoma in the nasal region which seemed to be induced by chromium. All patients have worked at the same chromate factory for 19 to 32 years. The first patient has suffered from squamous cell carcinoma of the left nasal cavity, starting 11 years after his retirement. He received radiotherapy followed by surgery. A malignant fibrous histiocytoma occurred in his left upper gingiva in a previously irradiated region, 7 years after the previous treatment. Surgery and chemotherapy for palliation failed to control the tumour, and he eventually expired. The other three patients underwent lobectomy for lung cancer. In cases 2 and 3, the tumour occurred in the left nasal cavity six and ten years, respectively, each after the lobectomy. In case 4, the tumour arose from the nasopharynx 15 years after the lobectomy. These patients are alive and well without any sign of tumour. The presented cases seem to be induced by long-term exposure to chromium. We conclude that regular physical examination of chromate workers is mandatory for the early detection not only of lung cancer but also of head-and-neck cancer.

[Evoked oto-acoustic emissions in patients with secretory otitis media].

In many studies, Evoked Otoacoustic Emissions (EOAEs) have been routinely documented in subjects with normal middle ear function showing tympanogram (TG) A type. However, middle ear dysfunction may influence the measurements of EOAEs. We investigated the EOAEs in ears with secretory otitis media (SOM) in order to understand the effects of middle ear dysfunction on EOAE measurements. We present data from 73 SOM ears of 38 subjects aged 3 to 58 (mean = 9.4 years) and data from 61 ears of 54 subjects with sensorineural hearing loss as a control. Generally, the EOAE thresholds of ears with mild sensorineural hearing loss have a good correlation with the audiometric hearing threshold level. On the other hand, the EOAE thresholds of ears with SOM were on the average higher than those expected from the audiometric hearing threshold level. In this paper, we classified TG B type further into TG B1 type and TG B2 type according to our criteria. Though neither TG B1 type nor TG B2 type revealed peaks in the tympanogram (-300mmH2O < or = < or = 200mmH2O), the 2 groups differ in that TG B1 type seems to have its peak at pressures under -300mmH2O on tympanography while TG B2 type seems to have no peaks in that pressure range. As a consequence of this classification, most of the EOAE thresholds of SOM ears showing TG B2 type were scaled out (> or = 40 or 50 dB nHL).(ABSTRACT TRUNCATED AT 250 WORDS)

[Changes in human spontaneous otoacoustic emissions with contralateral acoustic stimulation].

According to current cochlear concepts, spontaneous otoacoustic emissions (SOAEs) are thought to be the product of outer hair cell (OHCs) movement. Furthermore, efferent neurofibers from the olivocochlear bundle primarily innervate OHCs. Thus, we designed this investigation to determine changes in SOAE under conditions of contralateral acoustic stimulation. Fouty-two normal ears of 34 subjects with uni- or bilateral SOAEs were examined. The sound pressure level (SPL) of SOAE was measured 3 times in each subject and was initially averaged. The white noises of 30 or 40dBSPL, believed not to affect the other side, were then loaded contralaterally and the SPL of SOAEs were measured and compared with the non-loaded data. The SPL of single SOAEs were actually suppressed with 40dBSPL stimulation while the SPL of multiple SOAEs showed typical changes. Interestingly, no significant suppression of SOAEs was noticed under conditions of contralateral acoustic stimulation of the impaired ear. These data suggest that contralateral acoustic stimulation could affect OHC function via the olivocochlear bundle.

[Appropriate lymph node dissection in thyroid adenocarcinoma].

Thirty-four patients underwent thyroid surgery for papillary and follicular adenocarcinomas in the period from 1985 to 1989. Fourteen patients were treated with local neck dissection and 20 patients, with modified or radical neck dissection. Cervical lymph node metastasis was found in 25 patients (74%). Our recent policy for lymph node dissection is as follows: When deep cervical lymph node metastasis is clinically demonstrated, radical or modified neck dissection is performed. In patients without clinically demonstrated metastasis, local neck dissection and sampling of the internal jugular chain are performed. When microscopic metastasis is found in frozen sections, modified neck dissection is added. Thus we could select patients for modified neck dissection and choose appropriate neck dissection for more complete cancer clearance without losing postoperative functions.

An enzymatic method for the assay of serum argininosuccinate lyase.

A rapid enzymatic method was developed for the assay of serum argininosuccinate lyase (ASAL: EC 4.3.2.1) which is a useful marker enzyme for diagnosis of parenchymal liver diseases. Fumarate, liberated from argininosuccinate in the lyase-mediated reaction, was converted to pyruvate via L-malate by the actions of fumarase and malic enzyme in the presence of NADP+. The NADPH formed was then oxidized with a diaphorase-resazurin system to give a highly fluorescent resorufin. All the enzymatic reactions proceeded continuously in 0.1 M Tris-HCl buffer (pH 7.5) and allowed direct assay of ASAL in serum by monitoring the increase in the fluorescence intensity due to resorufin. The method is rapid and sensitive; only 50 microliter of serum is required. This method was used to detect increases in the activities in sera from patients with liver diseases.

A fluorometric method for the specific determination of serum arginine with 2,3-naphthalenedicarbaldehyde.

A specific and simple fluorometric method for the determination of serum arginine was developed which consists of (1) deproteinization of serum sample with 10% perchloric acid, (2) blocking thiol compounds with N-ethylmaleimide, (3) fluorescence reaction with 2,3-naphthalenedicarbaldehyde in 0.2 M borate buffer, pH 9.3, in the presence of beta-cyclodextrin (25 min at 20 degrees C, excitation wavelength: 462 nm, emission wavelength: 520 nm). Since the fluorescence reaction is highly specific for arginine, the method requires no other separation step. Linearity, recovery, and reproducibility of the method were found to be satisfactory.