Hearing loss before and after cisplatin-based chemotherapy in testicular cancer survivors: a longitudinal study.

BACKGROUND: Hearing loss is a well-known long-term effect after cisplatin-based chemotherapy (CBCT) in testicular cancer survivors (TCS), but longitudinal data are sparse. We evaluate hearing loss and the impact of age in TCS treated with CBCT in this longitudinal study. MATERIAL AND METHODS: Forty-six TCS treated with CBCT 1980-1994 with audiograms (0.25-8 kHz) pre-chemotherapy (PRE) and at a follow-up survey (SURV) after median 10 years were included (cases). Audiograms at SURV from 46 age-matched TCS without CBCT were included as controls. Linear regression was performed to evaluate predictors for change in the hearing threshold level (HTL) from PRE to SURV. Two definitions of a audiogram-defined hearing loss was applied if: (1) mean HTL for both ears exceeded 20 dB at any frequency 0.25-8 kHz (American Speech-Language-Hearing Association (ASHA) definition) and (2) average HTL for the frequencies 0.5, 1, 2 and 4 kHz exceeded 20 dB (WHO-M4 definition). Self-reported hearing impairment (SURV) was assessed by a questionnaire. RESULTS: Age and cisplatin dose was significantly associated with a greater change in HTL for the frequencies 2-8 kHz. For the 8 kHz frequency, each 100 mg increase in cumulative cisplatin dose was associated with a deterioration of 3.6 dB (95% CI 1.8-5.3, p < .001). The prevalence of hearing loss (ASHA) among cases was 33% PRE, 70% at SURV and 65% among controls at SURV (cases vs. controls, p = .66). According to M4, the prevalence of hearing loss among cases was 6.5% PRE, 13% at SURV and 2.2% among controls at SURV (cases vs. controls, p = .049). Twenty-nine percent of cases, and 33% of controls (p = .70) reported hearing impairment at SURV. CONCLUSION: Cisplatin is associated with a hearing loss particularly at higher frequencies. Age appear to be an important factor for hearing loss regardless of treatment. The ASHA definition overestimates the hearing problem.

Transient evoked otoacoustic emissions in rock musicians.

OBJECTIVE: Our focus in this study was the assessment of transient evoked otoacoustic emissions (TEOAEs) in a large group of rock musicians. A further objective was to analyse tinnitus among rock musicians as related to TEOAEs. DESIGN: The study was a cross-sectional survey of rock musicians selected at random. A control group was included at random for comparison. STUDY SAMPLE: We recruited 111 musicians and a control group of 40 non-musicians. Testing was conducted by using clinical examination, pure tone audiometry, TEOAEs and a questionnaire. RESULTS: TEOAE SNR in the half-octave frequency band centred on 4 kHz was significantly lower bilaterally in musicians than controls. This effect was strongly predicted by age and pure-tone hearing threshold levels in the 3-6 kHz range. Bilateral hearing thresholds were significantly higher at 6 kHz in musicians. Twenty percent of the musicians had permanent tinnitus. There was no association between the TEOAE parameters and permanent tinnitus. CONCLUSIONS: Our results suggest an incipient hearing loss at 6 kHz in rock musicians. Loss of TEOAE SNR in the 4 kHz half-octave frequency band was observed, but it was related to higher mean 3-6 kHz hearing thresholds and age. A large proportion of rock musicians have permanent tinnitus.

Hearing loss and tinnitus in rock musicians: A Norwegian survey.

Our focus in this study was to assess hearing thresholds and the prevalence and characteristics of tinnitus in a large group of rock musicians based in Norway. A further objective was to assess related factors such as exposure, instrument category, and the preventive effect of hearing protection. The study was a cross-sectional survey of rock musicians selected at random from a defined cohort of musicians. A random control group was included for comparison. We recruited 111 active musicians from the Oslo region, and a control group of 40 nonmusicians from the student population at the University of TromsØ. The subjects were investigated using clinical examination, pure tone audiometry, tympanometry, and a questionnaire. We observed a hearing loss in 37.8% of the rock musicians. Significantly poorer hearing thresholds were seen at most pure-tone frequencies in musicians than controls, with the most pronounced threshold shift at 6 kHz. The use of hearing protection, in particular custom-fitted earplugs, has a preventive effect but a minority of rock musicians apply them consistently. The degree of musical performance exposure was inversely related to the degree of hearing loss in our sample. Bass and guitar players had higher hearing thresholds than vocalists. We observed a 20% prevalence of chronic tinnitus but none of the affected musicians had severe tinnitus symptomatology. There was no statistical association between permanent tinnitus and hearing loss in our sample. We observed an increased prevalence of hearing loss and tinnitus in our sample of Norwegian rock musicians but the causal relationship between musical exposure and hearing loss or tinnitus is ambiguous. We recommend the use of hearing protection in rock musicians.

Calibration/Standardization of Short-Duration Stimuli.

This article provides a brief summary of issues relevant to the calibration and standardization of acoustic transients.

Evoked potentials in the Atlantic cod following putatively innocuous and putatively noxious electrical stimulation: a minimally invasive approach.

Aspects of peripheral and central nociception have previously been studied through recording of somatosensory evoked potentials (SEPs) to putative noxious stimuli in specific brain regions in a few freshwater fish species. In the present study, we describe a novel, minimally invasive method for recording SEPs from the central nervous system of the Atlantic cod (Gadus morhua). Cutaneous electric stimulation of the tail in 15 fish elicited SEPs at all stimulus intensities (2, 5, 10 and 20 mA) with quantitative properties corresponding to stimulus intensity. In contrast to previous fish studies, the methodological approach used in Atlantic cod in the current study uncovered a number of additional responses that could originate from multiple brain regions. Several of these responses were specific to stimulation at the highest stimulus intensities, possibly representing qualitative differences in central processing between somatosensory and nociceptive stimuli.

High-dose gentamicin in newborn infants: is it safe?

Dosing regimens often recommend lower gentamicin doses in neonates (3-5 mg/kg) than in older children (7 mg/kg or more) despite the higher volume of distribution in neonates. We studied an extended-interval high-dose (6 mg/kg) gentamicin regimen in a single tertiary neonatal unit from 2004-2012. During the first week of life, dosing interval was 24 h for term infants, 36 h for preterm infants with gestational age (GA) 29-36 weeks and 48 h for preterm infants with GA <29 weeks. After the first week of life, dosing interval was 24 h if corrected age (GA + postnatal age) ≥29 weeks and 36 h if corrected age <29 weeks. Outcome measures were trough plasma concentration (TPC), ototoxicity and prescription errors. In 546 treatment episodes, TPC was measured prior to the third gentamicin dose. There were 37 episodes (6.7 %) of prescription errors, mainly a too long dosing interval. We included 509 treatment episodes (440 infants) in the final analysis. Mean (standard deviation) gentamicin TPC during the first week of life was 1.1 (0.5) mg/L and after the first week of life 0.8 (0.6) mg/L. In 31 (6 %) episodes, TPC was ≥2.0 mg/L, predominantly among term infants with renal impairment. Thirty-eight patients failed the neonatal hearing screening, but only four of these 38 had permanent hearing loss. All four had a TPC <2.0 mg/L. Conclusions: This extended-interval high-dose gentamicin regimen was associated with low numbers of elevated TPCs, low numbers of prescription errors and no evidence for ototoxicity.

Damage and functional recovery of the Atlantic cod (Gadus morhua) inner ear hair cells following local injection of gentamicin.

This study addresses the ultrastructural and functional damage and subsequent recovery of the inner ear in the Atlantic cod following intrasaccular gentamicin injection. Inner ear damage was assessed using SEM and measurements of AEP following 250-Hz pure-tone stimuli. Data from gentamicin-treated fish were compared with control (no injection) and sham (injection of saline) fish. Control fish had normal response thresholds associated with well-developed hair cell bundles in their macula sacculi. Sham fish had higher response thresholds compared with control fish during the first week post-intervention, but response thresholds were subsequently normal. Treated fish displayed significant inner ear damage associated with an increased average AEP threshold on the third day following treatment. Thereafter, inner ear tissue displayed signs of progressive regeneration until it was comparable to controls from the 14th day. Response thresholds were similar to those of control fish from the 17th day following treatment. These observations suggest that the macula sacculi of Atlantic cod can regenerate towards a near-complete functional and ultrastructural recovery within 17-21 days following ototoxic gentamicin treatment.

Presbyacusis-hearing thresholds and the ISO 7029.

The purpose of this study was to analyse the changes in pure-tone hearing thresholds with age. We studied a random sample of 232 elderly subjects with a battery of audiological tests, including pure-tone audiometry in the conventional and extended high-frequency range, using the normative distributions from the International Organization for Standardization (ISO) standard 7029 for comparison. Sixty otologically normal (ON) subjects were selected for comparative analysis with the unscreened (US) sample, and for description of gender and age group differences. With the use of a mathematical transformation of threshold data, it was found that the ISO 7029 normative alpha coefficient in females may be set too low compared to our sample in the lower frequencies, leading to an underestimation of hearing thresholds in ON females. In our ON sample, hearing thresholds deteriorated with age in the extended high-frequency audiometric range. No gender threshold differences were found, although the prevalence of unmeasurable responses was higher in males at some of these frequencies. The ON screening criteria in ISO 7029 may be unreliable in subjects over 60 years of age, as threshold differences between ON and US subjects were not consistent at any frequency.

Cortical cognitive potentials in elderly persons.

The purpose of this study was to analyze the changes in the acoustically evoked cortical cognitive potentials N 200, P 300, and N 3 with age. There were 232 participants, who were 60 years or older, and each was examined using a battery of audiological tests including a questionnaire, otomicroscopy, pure-tone audiometry, and cortical cognitive potentials, measured at Fz using an auditory oddball paradigm. N 200 was elicited in 46.9%, P 300 in 45.1%, and N 3 in 52.2% of the elderly participants. The most significant predictors for presence of cortical responses were the participant's age and hearing level at target tone frequency. Monosyllabic speech recognition score was a less important predictor for presence of response. Response latency in the elderly sample increased steadily with age. Few changes in cortical response amplitude were found with age. We conclude that the speed of central auditory processing seems to be reduced with age.

The aging ear: an otomicroscopic and tympanometric study.

OBJECTIVES: To analyze changes in tympanometric measures with age and to study some otitis-related issues in the elderly (> or = 60 years) population. MATERIAL AND METHODS: The study was designed as a combination of a cross-sectional survey and a controlled study. We studied a random sample of 232 elderly subjects using an extended battery of audiological tests, including pure-tone audiometry. tympanometry with a probe frequency of 226 Hz, otomicroscopy and a standardized questionnaire. A sample of 60 otologically normal subjects were selected for comparative analysis with young healthy controls, and for description of age-related changes and gender differences. RESULTS: Using linear regression analyses of ear canal volume, middle ear pressure and tympanic membrane compliance on age, no consistently significant change in these parameters with age was found. When these measures were compared between the elderly and the controls, using parametric and non-parametric statistical tests, no significant differences were found for either gender. The only significant gender difference was found for ear canal volume, which was greater for elderly males than for elderly females In the unscreened elderly sample, the adjusted prevalence for reported previous or current otitis media was 15-27% of the population (95% CI). The adjusted prevalence for reported previous or current chronic otitis media (COM) or sequelae thereof was 1-7% (95% CI). With the exception of cerumen obstruction, the prevalence of outer ear canal-related complaints was 1-7% (95% CI). There were some discrepancies between these reported complaints and the findings at otomicroscopy. Although elderly subjects with COM were found to have poorer hearing at speech frequencies than normal elderly subjects. no such effect was found in subjects with scarring or atrophy of the tympanic membrane. The effect of pathological findings at otomicroscopy on tympanometric measures in the elderly sample was highly variable and no consistent association was found. CONCLUSIONS: No change in middle ear sound transmission, as assessed by tympanometry, occurs with normal aging. Ear canal volume is smaller in elderly females than elderly males, which is potentially relevant to the study of otoacoustic emissions in the elderly. The estimated prevalence of ear canal-related problems, excluding cerumen obstruction, is of such a magnitude that the introduction of partially implanted hearing aids may be warranted in our elderly population.

Transient evoked otoacoustic emissions in the elderly.

The purpose of this study was to analyse the changes in transient evoked otoacoustic emissions (TEOAEs) with age. We studied 232 subjects above 60 years of age with a battery of audiological tests, including TEOAEs Our criterion for the presence of TEOAEs was based on a cut-off at overall wave reproducibility 55% or overall response level 4 dB SPL. The prevalence of TEOAEs in left ears was 55.6%. No TEOAEs were found in subjects with a pure-tone average (PTA) above 40 dB HL. In the subgroup with TEOAEs, a significant decrease in overall wave reproducibility with age was found. We compared 45 normal-hearing elderly subjects with TEOAEs with a control group of 20 normal-hearing young adults The elderly had significantly lower mean overall response levels and mean overall wave reproducibility. Average hearing level was significantly higher in the elderly than in controls We conclude that the prevalence of TEOAEs decreases with age, and that the overall response level and overall reproducibility decrease with age. This decrease may not be seen in isolation from the increase in hearing threshold level.