Dennis Kin Kwok Au

Sensorineural hearing loss in patients treated for nasopharyngeal carcinoma: A prospective study of the effect of radiation and cisplatin treatment

PURPOSE The pattern of sensorineural hearing loss (SNHL) after primary treatment for nasopharyngeal carcinoma (NPC) was studied, and the effect of cisplatin, radiotherapy does, and fractionation were evaluated. METHODS AND MATERIALS One hundred thirty-two patients, 227 ears, and 1100 audiogram reports were analyzed. Radiotherapy dose ranged from 59.5 to 76.5 Gy. Fifty-two patients received preirradiation cisplatin, total dose 100-185 mg/m(2). Serial postirradiation bone conduction thresholds at 0.5 kHz, 1 kHz, 2 kHz, and 4 kHz were compared with pretreatment thresholds at respective frequencies. Increase of at least 15 dB was considered as significant and was further grouped as transient or persistent SNHL. Univariate and multivariate analyses were performed to identify predicting factors for persistent SNHL. RESULTS At median follow-up of 30 months, 24.2% of ears developed persistent SNHL. High frequency was more affected than low frequencies, 22 vs. 5.3%. Males were more affected than females, 29.4 vs. 15.5%, p = 0.0132. Incidence of persistent SNHL increased with age, with 0, 17.2, and 37.4% of patients aged under 30, between 30-50 and over 50 affected, respectively, p = 0.0001. High incidence was found in patient with postirradiation serous otitis media (SOM), 46.9%. Chemotherapy with cisplatin and radiation dose or fractionation had no significant effect. Multivariate analysis confirmed age, sex, and postirradiation SOM as significant prognostic factors for persistent SNHL. CONCLUSIONS Transient and persistent SNHL occurred after radiotherapy, more commonly affecting high frequency. A low dose of preirradiation cisplatin did not increase the risk. A dose fractionation effect of radiotherapy was not confirmed in this study.

Long-term sensorineural hearing deficit following radiotherapy in patients suffering from nasopharyngeal carcinoma: A prospective study.

This was a prospective study to evaluate the effect of radical external irradiation on inner ear function after treatment of nasopharyngeal carcinoma.

Chinese tonal language rehabilitation following cochlear implantation in children.

Cantonese language rehabilitation in 28 prelingually deaf children who underwent cochlear implantation was evaluated. All patients were implanted with multichannel devices and the operations went smoothly. They all had improved scores on audiological assessments and speech perception tests. The speech evaluation tests included the recognition of sounds, vowels, consonants and tone. Sentence recognition and story comprehension were both improved after training for 2 years. Cochlear implantation is a useful measure for the speech rehabilitation of prelingually profound deaf children when hearing aids are of no benefit. The multichannel implant device is of clinical significance in the rehabilitation of those patients using tonal language.Cantonese language rehabilitation in 28 prelingually deaf children who underwent cochlear implantation was evaluated. All patients were implanted with multichannel devices and the operations went smoothly. They all had improved scores on audiological assessments and speech perception tests. The speech evaluation tests included the recognition of sounds, vowels, consonants and tone. Sentence recognition and story comprehension were both improved after training for 2 years. Cochlear implantation is a useful measure for the speech rehabilitation of prelingually profound deaf children when hearing aids are of no benefit. The multichannel implant device is of clinical significance in the rehabilitation of those patients using tonal language.

Temporal fine structure in cochlear implants: Preliminary speech perception results in Cantonese-speaking implant users

Abstract Conclusion: Acute comparisons between continuous interleaved sampling (CIS) and a temporal fine structure (TFS) coding strategy in Cantonese-speaking cochlear implant (CI) users did not reveal any significant differences in speech perception. Performance with the unfamiliar TFS coding strategy was on a par with CIS. Benefits of extended fine structure use observed in other studies should be investigated for tonal languages. Objectives: CIS-based stimulation strategies lack an explicit representation of fine structure, which is crucial for tonal language speech perception. The aim of this study was to assess speech recognition with a TFS coding strategy in Cantonese-speaking CI users with no prior fine structure experience. Methods: The fine structure coding strategy encodes TFS on a few apical channels, while the remaining more basal channels carry CIS stimuli. Twelve MED-EL implantees and long-term CIS users participated in a study comparing recognition for Cantonese lexical tones and CHINT sentences between CIS and fine structure stimulation. Results: Mean tone identification scores in 12 subjects were 59.2% with CIS and 59.2% with fine structure stimulation using 4 TFS channels, mean scores of CHINT sentences in 8 subjects were 54.2% with CIS and 55.9% with TFS stimulation. Differences between the two strategies were not significant for any speech test. Two additional versions of TFS strategy and pulse rates were tested in six subjects. No significant differences between strategies were found.

Translation of the dizziness handicap inventory into Chinese, validation of it, and evaluation of the quality of life of patients with chronic dizziness

The aims of this study were 1) to translate the Dizziness Handicap Inventory (DHI) into Chinese and to validate it and 2) to use the Chinese DHI and the Chinese (Hong Kong) Short Form-36 Health Survey (Chinese [HK] SF-36) to evaluate the quality of life (QoL) of patients with chronic dizziness. Seventy-one patients with 6 months of dizziness due to vestibular dysfunction were evaluated initially, 7 days later (n = 49), and after 7 months of medical treatment (n = 17). The Chinese DHI has been shown to retain good test-retest reliability (intraclass correlation coefficient range, 0.64 to 0.87) and internal consistency (Cronbach α coefficient > 0.7) as compared to the original DHI and has a moderate responsiveness (0.54). We find the Chinese DHI to be a valid tool for evaluation of QoL of Chinese patients with dizziness. Low mean scores on the Chinese DHI and Chinese (HK) SF-36 signify that chronic dizziness has a considerable impact on the QoL of these patients.

Noise Exposure and Hearing Impairment among Chinese Restaurant Workers and Entertainment Employees in Hong Kong

Background Noise-induced hearing loss (NIHL) is a major concern in the non-manufacturing industries. This study aimed to investigate the occupational noise exposure and the NIHL among Chinese restaurant workers and entertainment employees working in the service industry in Hong Kong. Methods This cross-sectional survey involved a total of 1,670 participants. Among them, 937 were randomly selected from the workers of Chinese restaurants and 733 were selected from workers in three entertainment sectors: radio and television stations; cultural performance halls or auditoria of the Leisure and Cultural Services Department (LCSD); and karaoke bars. Noise exposure levels were measured in the sampled restaurants and entertainment sectors. Each participant received an audiometric screening test. Those who were found to have abnormalities were required to take another diagnostic test in the health center. The “Klockhoff digit” method was used to classify NIHL in the present study. Results The main source of noise inside restaurants was the stoves. The mean hearing thresholds showed a typical dip at 3 to 6 KHz and a substantial proportion (23.7%) of the workers fulfilled the criteria for presumptive NIHL. For entertainment sectors, employees in radio and television stations generally had higher exposure levels than those in the halls or auditoria of the LCSD and karaoke bars. The mean hearing thresholds showed a typical dip at 6 KHz and a substantial proportion of the employees fulfilled the criteria for presumptive NIHL (38.6%, 95%CI: 35.1–42.1%). Being male, older, and having longer service and daily alcohol consumption were associated with noise-induced hearing impairment both in restaurant workers and entertainment employees. Conclusion Excessive noise exposure is common in the Chinese restaurant and entertainment industries and a substantial proportion of restaurant workers and entertainment employees suffer from NIHL. Comprehensive hearing conservation programs should be introduced to the service industry in Hong Kong.

Correlation of Pure Tone Audiogram Results and Hearing Benefit of Tympanoplasty for Chronic Suppurative Otitis Media

The aim of this study was to evaluate the correlation between pure tone audiogram results and the subjective sensation of hearing benefit of patients who had tympanoplasty for chronic suppurative otitis media. This is a prospective study of 115 patients who had tympanoplasty between 1992 and 1994. The outcome, including a pure tone audiogram and the subjective sensation of hearing benefit, was evaluated at 1 year after operation. There were 63 (55%) patients with subjective hearing benefit after the tympanoplasty. The subjective sensation of hearing benefit correlated with the magnitude of the air conduction (AC) threshold reduction, and increased from 39% for an AC reduction of less than or equal to 10 dB to 100% for an AC reduction of more than 30 dB. The effect of the interaural AC threshold difference on the subjective sensation of hearing was not significant; improvement was felt by 92% of patients when the operated ear became the better hearing ear, and by 73% of patients when the operated ear remained the worse hearing ear. There was considerable discrepancy between the subjective hearing benefit and the pure tone audiogram results. A combination of parameters, including the air-bone gap, the AC threshold, and the subjective hearing change, is recommended in reporting the results of tympanoplasty.

Randomized evaluation of the audiologic outcome of ventilation tube insertion for middle ear effusion in patients with nasopharyngeal carcinoma

OBJECTIVE Complications after ventilation tube insertion for middle ear effusion in patients with nasopharyngeal carcinoma are frequent. This may compromise the overall benefit obtained from the procedure. This study evaluates the hearing improvement after tube insertion compared with observation alone to see if the benefits of the procedure outweigh its potential complications. DESIGN Prospective randomized controlled trial. SETTING Full clinical and emergency otolaryngologic services hospital in an academic institution. METHODS Patients with nasopharyngeal carcinoma and middle ear effusion were randomized for preradiotherapy ventilation tube insertion or observation. Audiologic assessment with a pure-tone audiogram was performed before the procedure, after ventilation tube insertion, and at fixed intervals after irradiation. Audiologic outcome was compared between the two groups. MAIN OUTCOME MEASURE Air-conduction threshold and air-bone gap on a pure-tone audiogram at different intervals after radiotherapy. RESULTS There was no significant difference in hearing threshold changes between the two groups for up to 4 years. Both groups had air-bone gap improvement following radiotherapy and the improvement was not significantly different between the two groups. The proportion of patients with closure of the air-bone gap on follow-up was not different between the two groups. CONCLUSIONS Ventilation tube insertion before radiotherapy did not offer additional hearing benefit when compared with observation alone. The procedure had no deleterious effect on hearing for up to 4 years.

ENT management of a child with CHARGE association.

The acronym CHARGE is used to describe specific congenital birth defects in children: colobomata, heart defect, atresia of the choanae, retarded growth or development, genital hypoplasia, and ear anomalies or deafness. CHARGE association with hearing impairment is a challenge to ENT surgeons. We report the case of a child with CHARGE association who underwent cochlear implantation using an unconventional surgical approach and review the postoperative speech perception results. The benefits of cochlear implantation in children with multiple congenital defects are discussed.

Short electrode insertion in cochlear implantation: speech perception performance of Cantonese-speaking subjects

Conclusions. Subjects with cochlear ossification derived benefits in terms of speech performance similar to those of the non-ossified group. It is thus recommended that the insertion of short electrode arrays should be considered an alternative choice for patients with cochlear ossification. Objective. Cochlear ossification has been recognized as a major obstacle to the full insertion of a multichannel cochlear implant electrode array. To alleviate the technical difficulty of placing a standard electrode array and the possibility of causing undesirable trauma to the cochlea, a newly designed electrode array with the same number of electrodes compressed into a shorter length has been made available. The aim of the present study was to examine the speech perception performance of patients implanted with the MED-EL C40 + S compressed electrode array and to compare their results with those of matched groups implanted with the MED-EL C40 + standard electrode array. Material and methods. One pre-lingually and two post-lingually deaf subjects using short electrode arrays were matched with three groups of subjects using standard electrode arrays. The pre- and postoperative speech perception scores were evaluated. Results. All three subjects using compressed electrode arrays achieved speech perception scores comparable to those of matched subjects using standard electrode arrays. There was also a tendency for the subjects to show similar patterns of speech perception scores as a function of the difficulty of the tests.