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Summating Potential-Action Potential Waveform Amplitude and Width in the Diagnosis of Menière's Disease†

Objectives: It has been suggested that analyzing the width and amplitude of the summating potential‐action potential (SP‐AP) waveforms can increase the sensitivity of electrocochleography. The objective of this study was to evaluate the ratio of SP to AP amplitude (SP/AP) and SP‐AP waveform width, as well as the AP latency difference to condensation and rarefaction clicks, for the diagnosis of Menières disease.

Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects

INTRODUCTION Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. AIM Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. MATERIALS AND METHODS In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. RESULTS The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. CONCLUSION ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation.Introduction: Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. Aim: Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. Materials and methods: In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. Results: The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. Conclusion: ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation.

Comparison between thyroplasty type I andArytenoid rotation: a study of vocal fold vibration using excised human larynges

The purpose of this paper was to compare the vibration of the vocal fold submitted to Isshiki thyroplasty type I (TPI) to that of the contralateral one adducted by the arytenoid rotation (AR) technique. The vocal folds of ten human fresh excised larynges were medialized by TPI on one side and by rotation of the arytenoid on the contralateral side. Laryngeal vibration was artificially produced and was recorded by videostroboscopy. The images were subjectively and objectively analyzed. Subjective analysis included periodicity of vibratory cycles, features of the mucosal wave present on the TPI side, amplitude of vibration, and profile of free border of each vocal fold during the opening phase. Objective analyses were carried out on frame-by-frame digitalized images to determine amplitudes of vibrations and phase differences between the folds in three glottic regions (anterior, middle, and posterior). Subjective analysis revealed regular periodicity in 100% of the larynges, a decrease in the mucosal wave on the TPI side in 70%, reduction in amplitude in 30%, and a sigmoid profile of the free border on the TPI side in 80%. Objective analysis showed mean amplitude in the posterior glottic region on the TPI side significantly larger than that on the arytenoids rotation side and phase asymmetry in 90% of the larynges.

Estudo comparativo entre audiometria tonal limiar e resposta auditiva de estado estável em normouvintes

INTRODUCTION Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. AIM Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. MATERIALS AND METHODS In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. RESULTS The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. CONCLUSION ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation.Introduction: Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. Aim: Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. Materials and methods: In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. Results: The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. Conclusion: ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation.

Are auditory steady-state responses a good tool prior to pediatric cochlear implantation?

INTRODUCTION ASSR allow frequency-specific evaluation in intensities up to 120dB HL and detection of residual hearing in patients with severe-to-profound hearing loss. AIM to compare ASSR thresholds and behavioral test results in children with suspected severe-to-profound hearing loss. METHODS Cross sectional study to compare ASSR and behavioral responses (VRA or audiometry) in 63 pediatric cochlear implant candidates (126 ears) aged between 6 and 72 months. We included children with normal otomicroscopy, absent responses to click-ABR and otoaccoustic emissions. We excluded children with inner ear malformations, auditory neuropathy spectrum disorder or who did not complete VRA or achieve EEG noise<30nV during the ASSR test. Air-conduction ASSR stimuli were continuous sinusoidal tones presented at 0.5, 1, 2 and 4kHz starting at 110dB HL. Behavioral thresholds were acquired with warble tones presented at 0.5, 1, 2 and 4kHz in each ear through insert or head phones at maximum presentation level of 120dB HL. RESULTS Behavioral thresholds were obtained in 36.7% (185/504) of all frequencies in all subjects, 9% in intensities >110dB HL. Among 504 ASSR measurements, 53 thresholds were obtained (10.5%). Overall 89.5% of the tested frequencies did not show any response at 110dB HL. Most responses were at 500Hz. Mean differences between behavioral and ASSR thresholds varied from 0.09 to 8.94dB. Twenty-seven comparisons of behavioral and ASSR thresholds were obtained: 12 at 0.5kHz, 9 at 1kHz, 5 at 2kHz and 1 at 4kHz. Absent responses were observed in both tests in 38.1% at 0.5kHz, 52.4% at 1kHz, 74.6% at 2kHz and 81.0% at 4kHz. Specificity was>90% at 1, 2 and 4kHz. In ears with no behavioral response at 120dB HL all ASSR thresholds were in the profound hearing loss range, 90% of them were ≥110dB HL. CONCLUSION Among 63 pediatric CI candidates, absent responses to high-intensity ASSR was the major finding (specificity>90%) predicting behavioral thresholds in the profound hearing loss range. These findings can be helpful to confirm the decision for cochlear implantation.

Are Auditory Steady-State Responses Useful to Evaluate Severe-to-Profound Hearing Loss in Children?

Objective. To evaluate Auditory Steady-State Responses (ASSR) at high intensities in pediatric cochlear implant candidates and to compare the results to behavioral tests responses. Methods. This prospective study evaluated 42 children with suspected severe-to-profound hearing loss, aged from 3 to 72 months. All had absent ABR and OAE responses. ASSR were evoked using binaural single frequency stimuli at 110 dB HL with a 10 dB down-seeking procedure. ASSR and behavioral test results were compared. Results. Forty-two subjects completed both ASSR and behavioral evaluation. Eleven children (26.2%) had bilateral responses. Four (9.5%) showed unilateral responses in at least two frequencies, all confirmed by behavioral results. Overall 61 ASSR responses were obtained, most (37.7%) in 500 Hz. Mean thresholds were between 101.3 and 104.2 dB HL. Among 27 subjects with absent ASSR, fifteen had no behavioral responses. Seven subjects showed behavioral responses with absent ASSR responses. No spurious ASSR responses were observed at 100 or 110 dB HL. Conclusion. ASSR is a valuable tool to detect residual hearing. No false-positive ASSR results were observed among 42 children, but in seven cases with absent ASSR, the test underestimated residual hearing as compared to the behavioral responses.

Normative data for TM electrocochleography measures

Objective Establish normative data for tympanic electrocochleography (TM ECochG) parameters in normal hearing adults without Ménières diseases (MD) symptoms. Describe TM ECochG variables that help to distinguish normal from MD ears. Material and methods We enrolled 100 subjects (N = 200 ears), 59 females, aged between 19 and 71 years from 09/2010 to 04/2014. Inclusion criteria: normal otomicroscopy, hearing thresholds ≤25 dB nHL from 250 to 4000 Hz, normal tympanogram, no symptoms of MD according to the AAO-HNS 1995 criteria and Gibsons score <7. We excluded subjects with dizziness, aural fullness or other symptoms of endolymphatic hydrops. The following parameters were analyzed: SP/AP amplitude ratio, SP/AP area ratio and the difference between AP latency with rarefaction and condensation stimuli. Results There was no significant difference between right and left ears (Intraclass correlation coefficient < 0.6). SP/AP amplitude ratio varied between 0.084 and 0.356 and SP/AP area ratio between 0.837 and 1.671 (percentiles 5 and 95). The AP latency difference to rarefaction and condensation clicks was between 0.0 and 0.333 ms. Conclusion Normative data for TM ECochG parameters were established in 100 normal hearing subjects without MD. These data can be used to distinguish normal from pathological findings and in follow-up of MD patients.

Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects✩✩Please cite this article as: Beck RM, Ramos BF, Grasel SS, Ramos HF, Moraes MF, Almeida ER, et al. Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects. Braz J Otorhinolaryngol. 2014;80:35-40.

INTRODUCTION Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. AIM Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. MATERIALS AND METHODS In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. RESULTS The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. CONCLUSION ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation.Introduction: Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. Aim: Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. Materials and methods: In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. Results: The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. Conclusion: ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation.

81: Proeminent Ears—Modification of Davis' and Stenstron's Techniques

Objective: Facial nerve monitor use has become standard in neurotologic dissections, but the effect of electrical stimulation has never been studied in isolation. This study uses an animal model to assess the effects of intradural electrical stimulation. Methods: The intracanalicular facial nerve was exposed and stimulated in 10 rabbits. Five rabbits served as controls. Facial nerve function was observed and graded for 3 days postoperatively. A blink reflex EMG was done on day 3. Results: Stimulation did not cause decremental threshold response in animals exposed to five l-minute intervals at 0.5 mA. These animals exhibited normal facial function postoperatively, and EMG findings did not show weakness. Conclusions: The intradural facial nerve in this rabbit model was able to resist significant functional injury, despite the potential trauma of exposure and electrical stimulation, in 10 of 10 cases. Monitoring the intradural facial nerve should not significantly damage nerve function or cause a decremental threshold response.