Sensorineural hearing loss in combined modality treatment of nasopharyngeal carcinoma.
(65/499)
BACKGROUND: Combined modality therapy has become the standard of care for nasopharyngeal carcinoma, yet the combined ototoxic effects of radiation and cisplatin are poorly understood. The incidence and severity of sensorineural hearing loss (SNHL) with combined modality therapy was evaluated and the dose-response relation between radiation and hearing loss was investigated. METHODS: Patients with newly diagnosed AJCC Stage II-IVB nasopharynx carcinoma treated from 1994-2003 were identified. The records of 44 ears in 22 patients who received a preirradiation pure tone audiogram and followup audiograms 12+ months postirradiation were included in the analysis. All patients were treated with conformal radiotherapy to 70 Gy and received platinum-based chemotherapy similar to the Intergroup 0099 trial. Composite cochlear dose distributions were calculated. Ototoxicity was measured using intrasubject audiogram comparisons and SNHL was defined as per the American Speech and Hearing Association guidelines, with standard range of speech between 2000-4000 Hz. SNHL was analyzed using Fisher exact test and linear and logistic regression models. RESULTS: PATIENT CHARACTERISTICS: median age, 45; 27% Asian; 68% male; 64% WHO III. Median audiologic followup was 29 months (range, 12-76 mos). Mean cochlear dose (Dmean) ranged from 28.4-70.0 Gy (median, 48.5 Gy). SNHL was detected in 25 of the 44 ears (57%) studied. There was an increased risk of SNHL for ears receiving Dmean > 48 Gy compared with those receiving < or = 48 Gy at all frequencies within the range of speech (P = 0.04). Using univariate logistic regression analysis, Dmean to the cochlea, cycles of cisplatin, and time postradiotherapy were independently significant factors in determining the incidence of SNHL (P = 0.02, P = 0.03, and P = 0.04, respectively). In univariate and multivariate linear regression analysis, Dmean was statistically significant at all frequencies in affecting degree of SNHL, whereas the significance of cisplatin and time was variable. CONCLUSIONS: There was a significant increase in risk of SNHL among patients receiving > 48 Gy, suggesting a threshold in cochlear radiation dose-response in the setting of combined modality therapy. This dose should serve as a Dmean constraint maximum for intensity-modulated radiotherapy treatment of nasopharynx carcinoma. (+info)
Tinnitus in normally hearing patients: clinical aspects and repercussions.
(66/499)
Patients with tinnitus and normal hearing constitute an important group, given that findings do not suffer influence of the hearing loss. However, this group is rarely studied, so we do not know whether its clinical characteristics and interference in daily life are the same of those of the patients with tinnitus and hearing loss. AIM: To compare tinnitus characteristics and interference in daily life among patients with and without hearing loss. STUDY DESIGN: Historic cohort. MATERIAL AND METHOD: Among 744 tinnitus patients seen at a Tinnitus Clinic, 55 with normal audiometry were retrospectively evaluated. The control group consisted of 198 patients with tinnitus and hearing loss, following the same protocol. We analyzed the patients' data as well as the tinnitus characteristics and interference in daily life. RESULTS: The mean age of the studied group (43.1 +/- 13.4 years) was significantly lower than that of the control group (49.9 +/- 14.5 years). In both groups, tinnitus was predominant in women, bilateral, single tone and constant, but there were no differences between both groups. The interference in concentration and emotional status (25.5% and 36.4%) was significantly lower in the studied group than that of the control group (46% and 61.6%), but it did not happen in regard to interference over sleep and social life. CONCLUSIONS: Patients with tinnitus and normal hearing showed similar characteristics when compared to those with hearing loss. However, the age of the patients and the interference over concentration and emotional status were significantly lower in this group. (+info)
Level dependence of auditory filters in nonsimultaneous masking as a function of frequency.
(67/499)
Auditory filter bandwidths were measured using nonsimultaneous masking, as a function of signal level between 10 and 35 dB SL for signal frequencies of 1, 2, 4, and 6 kHz. The brief sinusoidal signal was presented in a temporal gap within a spectrally notched noise. Two groups of normal-hearing subjects were tested, one using a fixed masker level and adaptively varying signal level, the other using a fixed signal level and adaptively varying masker level. In both cases, auditory filters were derived by assuming a constant filter shape for a given signal level. The filter parameters derived from the two paradigms were not significantly different. At 1 kHz, the equivalent rectangular bandwidth (ERB) decreased as the signal level increased from 10 to 20 dB SL, after which it remained roughly constant. In contrast, at 6 kHz, the ERB increased consistently with signal levels from 10 to 35 dB SL. The results at 2 and 4 kHz were intermediate, showing no consistent change in ERB with signal level. Overall, the results suggest changes in the level dependence of the auditory filters at frequencies above 1 kHz that are not currently incorporated in models of human auditory filter tuning. (+info)
A new side effect of immunosuppression: high incidence of hearing impairment after liver transplantation.
(68/499)
Little is known about hearing impairment in patients after organ transplantation. We conducted a single-center study to evaluate hearing impairment in patients after orthotopic liver transplantation (OLT). A questionnaire was sent to 695 adult patients after OLT to assess characteristics and course of auditory impairment. Risk factors such as ototoxic drugs were taken into consideration. Clinical follow-up, including immunosuppressive therapy, was analyzed in detail. The questionnaire was completed by 521 patients (75%). Hearing impairment was reported by 184 patients (35%). A total of 43 patients (8%) suffered from hearing abnormalities prior to OLT. The remaining 141 patients (27%) developed hearing impairment after transplantation. Main problems were hearing loss (52%), tinnitus (38%), and otalgia (30%). There was no association of post-OLT hearing disorders with age or known risk factors. In 43% of patients, onset of hearing impairment was within 2 yr post-OLT. Hearing loss was positively associated with tacrolimus immunosuppression in univariate (P < 0.05) and multivariate analysis (P < 0.02). Patients using a hearing aid received tacrolimus more frequently than cyclosporine (P < 0.05). In conclusion, subjective hearing impairment is frequent in patients after OLT and contributes to post-OLT morbidity. Calcineurin inhibitor-related neurotoxicity appears as a possible mechanism. Further prospective investigations with objective hearing tests are necessary to confirm these results and to evaluate the role of immunosuppression. (+info)
Hearing health and care: the need for improved hearing loss prevention and hearing conservation practices.
(69/499)
Hearing loss affects 31 million Americans, particularly veterans who were exposed to harmful levels of noise during military functions. Many veterans also receive treatment with ototoxic medications, which may exacerbate preexisting hearing loss. Thus, hearing loss is the most common and tinnitus the third most common service-connected disability among veterans. Poor implementation of hearing protection programs and a lack of audiometric testing during medical treatment leave veterans vulnerable to unrecognized and untreated hearing loss until speech communication is impaired. Individualized audiometric testing techniques, including assessment of high frequencies, can be used in clinical and occupational settings to detect early hearing loss. Antioxidants also may alleviate cochlear damage caused by noise and ototoxicity. Ultimately, hearing loss prevention requires education on reducing occupational and recreational noise exposure and counseling on the risks and options available to patients. Technological advances will improve monitoring, allow better noise engineering controls, and lead to more effective hearing protection. (+info)
Speech signals used to evaluate functional status of the auditory system.
(70/499)
This review presents a brief history of the evolution of speech audiometry from the 1800s to present day. The two-component aspect of hearing loss (audibility and distortion), which was formalized into a framework in past literature, is presented in the context of speech recognition. The differences between speech recognition in quiet and in background noise are discussed as they relate to listeners with normal hearing and listeners with hearing loss. A discussion of the use of sentence materials versus word materials for clinical use is included as is a discussion of the effects of presentation level on recognition performance in quiet and noise. Finally, the effects of age and hearing loss on speech recognition are considered. (+info)
A case-control auditory evaluation of patients treated with artemether-lumefantrine.
(71/499)
Artemether-lumefantrine is the first registered, fixed, artemisinin-based combination treatment. Artemisinin derivatives are highly effective antimalarials with a favorable safety profile. Concerns remain over their potential neurotoxicity, although there has been no clinical evidence of this in humans. In animals (rats, dogs, and monkeys) artemether, a derivative of artemisinin is associated with an unusual toxicity pattern in specific brain nuclei involving the auditory and vestibular pathways. A recent report from Mozambique described a small but significant and irreversible hearing loss in patients exposed to artemether-lumefantrine. To explore this issue, we conducted a case-control study using tympanometry, audiometry and auditory brain-stem responses. We assessed 68 subjects who had been treated with artemether-lumefantrine within the previous five years and 68 age- and sex-matched controls living in the malarious region along the Thailand-Myanmar border. There were no differences in the test results between cases and controls. There was no neurophysiologic evidence of auditory brainstem toxicity that could be attributed to artemether-lumefantrine in this study population. (+info)
Relationship between cisplatin administration and the development of ototoxicity.
(72/499)
PURPOSE: To determine the auditory toxicity associated with dose- and schedule- intensive cisplatin/gemcitabine chemotherapy in non-small-cell lung carcinoma patients. PATIENTS AND METHODS: Patients were treated with gemcitabine followed by cisplatin according to an interpatient dose-escalation scheme. Patients were randomly assigned to receive treatment once a week for 6 weeks or once every 2 weeks for 4 weeks. The following cohorts of patients were treated with a reversed schedule once every 2 weeks, in which cisplatin was followed by gemcitabine. The dose-intensity of cisplatin was equal in both schedules. Audiometric evaluations were obtained for each ear at several frequencies. Mean hearing loss after cisplatin treatment was computed for each dose level at each tested frequency in each ear at baseline and subsequent follow-up audiometry. Pure tone averages (PTAs) were also calculated. The pharmacokinetics of cisplatin was determined to study the correlation among the maximum drug concentration, the area under the curve of unbound platinum, and the development of ototoxicity. RESULTS: A total of 328 audiograms were analyzed. At the higher frequencies, a more severe hearing impairment was recorded. Most patients showed a decrease in hearing thresholds at dosages above 60 mg/m2 cisplatin at the higher frequencies. PTAs at 1, 2, and 4 kHz show a mean hearing loss of 19 dB after cisplatin administration at dosages above 90 mg/m2. Threshold shifts at 8 and 12.5 kHz after cisplatin administration were experienced at dosages above 60 mg/m2. CONCLUSION: Hearing loss after cisplatin therapy occurs mainly at high frequencies and at cisplatin dosages more than 60 mg/m2. It is more pronounced when cisplatin is given once every 2 weeks. (+info)