Biomedical subjects

Y Sininger

Publications and source records attributed to Y Sininger.

10 recordsLinked to original sources

PubMed2000

Identification of neonatal hearing impairment: a multicenter investigation.

OBJECTIVES: This article describes the design of a multicenter study sponsored by the National Institutes of Health. The purpose of this study was to determine the accuracy of three measures of peripheral auditory system status (transient evoked otoacoustic emissions, distortion product otoacoustic emissions, and auditory brain stem responses) applied in the perinatal period for predicting behavioral hearing status at 8 to 12 mo corrected age. The influences of the infant's medical status, the test environment, and test and response parameters on test performance were examined. DESIGN: Seven institutions participated in this study. There were 7179 infants evaluated in the perinatal period. All graduates of the neonatal intensive care unit (4478) and well babies with one or more risk factor for hearing loss (353) were targeted for follow-up testing using visual reinforcement audiometry (VRA) at 8 to 12 mo corrected age. Well babies without any risk indicators (N = 2348) were not targeted for follow-up VRA testing. However, 80 of these well babies did not pass the screening protocol and thus were targeted for follow-up VRA testing as well. Perinatal test performance was evaluated using the VRA data as the "gold standard." RESULTS: The results of this study are described in a series of 11 articles following this introductory article. CONCLUSIONS: The evaluation of newborn hearing tests required a longitudinal study in which newborn test results were compared with a gold standard based on behavioral audiometric assessment. Such an evaluation was possible because all newborns, passes as well as refers, were followed up long enough to permit reliable behavioral measurements. In addition, prenatal, perinatal, and maternal history information, test environment, and test parameter information were collected to provide data that led to a complete description of factors affecting test outcomes. All of these data were obtained in a sample of sufficient ethnic, medical, and geographic diversity in efforts to increase the generalizability of the results. Finally, the data were combined in a relational data base to examine the factors that influence test performance. Specific information related to these issues is presented in the articles that follow.

Evoked Potentials, Auditory, Brain Stem↗

PubMed2000

Identification of neonatal hearing impairment: evaluation of transient evoked otoacoustic emission, distortion product otoacoustic emission, and auditory brain stem response test performance.

OBJECTIVES: The purpose of this study was to compare the performance of transient evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs), and auditory brain stem responses (ABRs) as tools for identification of neonatal hearing impairment. DESIGN: A total of 4911 infants including 4478 graduates of neonatal intensive care units, 353 well babies with one or more risk factors for hearing loss (Joint Committee on Infant Hearing, 1994) and 80 well babies without risk factor who did not pass one or more neonatal test were targeted as the potential subject pool on which test performance would be assessed. During the neonatal period, they were evaluated using TEOAEs in response to an 80 dB pSPL click, DPOAE responses to two stimulus conditions (L1 = L2 = 75 dB SPL and L1 = 65 dB SPL L2 = 50 dB SPL), and ABR elicited by a 30 dB nHL click. In an effort to describe test performance, these "at-risk" infants were asked to return for behavioral audiologic assessments, using visual reinforcement audiometry (VRA) at 8 to 12 mo corrected age, regardless of neonatal test results. Sixty-four percent of these subjects returned and reliable VRA data were obtained on 95.6% of these returnees. This approach is in contrast to previous studies in which, by necessity, efforts were made to follow only those infants who "failed" the neonatal screening tests. The accuracy of the neonatal measures in predicting hearing status at 8 to 12 mo corrected age was determined. Only those infants who provided reliable, monaural VRA test results were included in the analysis. Separate analyses were performed without regard to intercurrent events (i.e., events between the neonatal and VRA tests that could cause their results to disagree), and then after accounting for the possible influence of intercurrent events such as otitis media and late-onset or progressive hearing loss. RESULTS: Low refer rates were achieved for the stopping criteria used in the present study, especially when a protocol similar to the one recommended in the National Institutes of Health (1993) Consensus Conference Report was followed. These analyses, however, do not completely describe test performance because they did not compare neonatal screening test results with a gold standard test of hearing. Test performance, as measured by the area under a relative operating characteristic curve, were similar for all three neonatal tests when neonatal test results were compared with VRA data obtained at 8 to 12 mo corrected age. However, ABRs were more successful at determining auditory status at 1 kHz, compared with the otoacoustic emission (OAE) tests. Performance was more similar across all three tests when they were used to identify hearing loss at 2 and 4 kHz. No test performed perfectly. Using either the two- or three-frequency pure-tone average (PTA), with a fixed false alarm rate of 20%, hit rates for the neonatal tests, in general, exceeded 80% when hearing impairment was defined as behavioral thresholds > or =30 dB HL. All three tests performed similarly when a two-frequency (2 and 4 kHz) PTA was used as the gold standard; OAE test performance decreased when a three-frequency PTA (adding 1 kHz) was used as the gold standard definition. For both PTA and all three neonatal screening measures, however, hit rate increased as the magnitude of hearing loss increased. CONCLUSIONS: Singly, all three neonatal hearing screening tests resulted in low refer rates, especially if referrals for follow-up were made only for the cases in which stopping criteria were not met in both ears. Following a protocol similar to that recommended in the National Institutes of Health (1993) Consensus Conference report resulted in refer rates that were less than 4%. TEOAEs at 80 dB pSPL, DPOAE at L1 = 65, L2 = 50 dB SPL and ABR at 30 dB nHL measured during the neonatal period, and as implemented in the current study, performed similarly at predicting behavioral hearing status at 8 to 12

Acoustic Stimulation↗

PubMed2000

Identification of neonatal hearing impairment: summary and recommendations.

OBJECTIVES: This article summarizes the results of a multi-center study, "Identification of Neonatal Hearing Impairment," sponsored by the National Institutes of Health. The purpose of this study was to determine the performance characteristics of three measures of peripheral auditory system status, transient evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs), and auditory brain stem responses (ABR), applied in the neonatal period in predicting hearing status at 8 to 12 mo corrected age. DESIGN: The design and implementation of this study are described in the first two articles in this series. Seven institutions participated in this study; 7179 infants were evaluated. Graduates of the neonatal intensive care unit and well babies with one or more risk factors for hearing loss were targeted for follow-up testing using visual reinforcement audiometry (VRA) at 8 to 12 mo corrected age. Neonatal test performance was evaluated using the VRA data as the "gold standard." RESULTS: The major results of the study are described in the nine articles preceding this summary article. TEOAEs in response to an 80 dB pSPL click, DPOAEs in response to L1 = 65 and L2 = 50 dB SPL and ABR in response to a 30 dB nHL click performed well as predictors of permanent hearing loss of 30 dB or greater at 8 to 12 mo corrected age. All measures were robust with respect to infant state, test environment and infant medical status. No test performed perfectly. CONCLUSIONS: Based on the data from this study, the 1993 National Institutes of Health Consensus Conference-recommended protocol-an OAE test followed by an ABR test for those infants failing the OAE test-would result in low referral rate (96 to 98%). TEOAEs for 80 dB pSPL, ABR for 30 dB nHL and DPOAEs for L1 = 65 dB SPL and L2 = 50 dB SPL perform well in predicting hearing status based on the area under the relative operating characteristic curve. Accuracy for the OAE measurements are best when the speech awareness threshold or the pure-tone average for 2.0 kHz and 4 kHz are used as the gold standard. ABR accuracy varies little as a function of the frequencies included in the gold standard. In addition, 96% of those infants returning for VRA at 8 to 12 mo corrected age were able to provide reliable ear-specific behavioral thresholds using insert earphones and a rigorous psychophysical VRA protocol.

Evoked Potentials, Auditory, Brain Stem↗

PubMed1999

Temporal and speech processing deficits in auditory neuropathy.

Auditory neuropathy affects the normal synchronous activity in the auditory nerve, without affecting the amplification function in the inner ear. Patients with auditory neuropathy often complain that they can hear sounds, but cannot understand speech. Here we report psychophysical tests indicating that these patients' poor speech recognition is due to a severe impairment in their temporal processing abilities. We also simulate this temporal processing impairment in normally hearing listeners and produce similar speech recognition deficits. This study demonstrates the importance of neural synchrony for auditory perceptions including speech recognition in humans. The results should contribute to better diagnosis and treatment of auditory neuropathy.

Acoustic Stimulation↗

PubMed1999

Hereditary auditory, vestibular, motor, and sensory neuropathy in a Slovenian Roma (Gypsy) kindred.

Members of a Roma (Gypsy) family with hereditary motor and sensory peripheral neuropathy (HMSN) and concomitant auditory and vestibular cranial neuropathies were identified in Kocevje, Slovenia. The illness begins in childhood with a severe and progressive motor disability and the deafness is delayed until the second decade. There are no symptoms of vestibular dysfunction. The family structure is consistent with an autosomal recessive pattern of inheritance and the genetic locus for the disorder is linked to the same region of chromosome 8q24 as other Roma families with HMSN and deafness from Lom, Bulgaria (HMSN-Lom). The present study shows that the deafness is caused by a neuropathy of the auditory nerve with preserved measures of cochlear outer hair cell function (otoacoustic emissions and cochlear microphonics) but absent neural components of auditory brainstem potentials. The hearing loss affects speech comprehension out of proportion to the pure tone loss. Vestibular testing showed absence of caloric responses. Physiological and neuropathological studies of peripheral nerves were compatible with the nerve disorder contemporaneously affecting Schwann cells and axons resulting in both slowed nerve conduction and axonal loss. Genetic linkage studies suggest a refinement of the 8q24 critical region containing the HMSN-Lom locus that affects peripheral motor and sensory nerves as well as the cranial auditory and vestibular nerves.

Acoustic Stimulation↗

PubMed1998

Transient deafness due to temperature-sensitive auditory neuropathy.

OBJECTIVE: To define mechanisms accounting for transient deafness in three children (two siblings, ages 3 and 6, and an unrelated child, age 15) when they become febrile. DESIGN: Audiometric tests (pure-tone audiometry, speech and sentence comprehension), tympanometry, middle ear muscle reflex thresholds, otoacoustic emissions (OAEs), and electrophysiological methods (auditory brain stem responses [ABRs], sensory evoked potentials, peripheral nerve conduction velocities) were used to test the children when they were afebrile and febrile. RESULTS: ABRs, when afebrile, were abnormal with a profound delay of the IV-V and absence of waves I-III. The ABR in one of the children, tested when febrile, showed no ABR components. Measures of cochlear receptor function using OAEs were normal in both febrile and afebrile states. Cochlear microphonic potentials were present in the three children, and a summating potential was likely present in two. When afebrile, there was a mild threshold elevation for all frequencies in the 15-yr-old and a mild elevation of thresholds for just low frequencies in the two siblings. Speech comprehension in quiet was normal but impaired in noise. One of the siblings tested when febrile had a profound elevation (>80 dB) of pure-tone thresholds and speech comprehension was absent. Acoustic reflexes subserving middle ear muscles and olivocochlear bundle were absent when febrile and when afebrile. No other peripheral or cranial nerve abnormalities were found in any of the children. Sensory nerve action potentials from median nerve in one of the children showed no abnormalities on warming of the hand to 39 degrees C. CONCLUSION: These children have an auditory neuropathy manifested by a disorder of auditory nerve function in the presence of normal cochlear outer hair cell functions. They develop a conduction block of the auditory nerves when their core body temperature rises due, most likely, to a demyelinating disorder of the auditory nerve. The auditory neuropathy in the two affected siblings is likely to be inherited as a recessive disorder.

Acoustic Impedance Tests↗

PubMed1998

Auditory neuropathy in childhood.

OBJECTIVES: Auditory neuropathy is a recently described disorder in which patients demonstrate hearing loss for pure tones, impaired word discrimination out of proportion to pure tone loss, absent or abnormal auditory brainstem responses, and normal outer hair cell function as measured by otoacoustic emissions and cochlear microphonics. We have identified eight pediatric patients having hearing deficits that are most likely due to a neuropathy of the eighth nerve. In this study, the results of audiologic testing performed with these eight children are described. STUDY DESIGN: Retrospective review of audiologic findings in eight children with auditory neuropathy. METHODS: Each subject was tested with pure tone and speech audiologic testing, auditory brainstem response, and click-evoked otoacoustic emissions. Results of these tests were tabulated and summarized. RESULTS: Pure tone audiologic testing revealed five children with upsloping sensorineural hearing loss, two with high frequency loss, and one with a mild, flat configuration. Six children demonstrated poor word discrimination scores, and the other two had fair to good word discrimination. All eight subjects had normal distortion product and transient otoacoustic emissions. All eight children demonstrated absent or marked abnormalities of brainstem auditory evoked potentials. These findings suggest that while cochlear outer hair cell function is normal, the lesion is located at the eighth nerve. CONCLUSIONS: Recent advances in otoacoustic emissions testing permit differentiation of neural deafness from sensory deafness. This paper describes the clinical presentation and audiologic findings in pediatric auditory neuropathy, as well as the recommended management of these patients. Otolaryngologists should be aware of this disorder and implications for its management, which differs from treatment of sensorineural hearing loss.

Adolescent↗

PubMed1996

Auditory neuropathy.

Ten patients presented as children or young adults with hearing impairments that, by behavioural and physiological testing, were compatible with a disorder of the auditory portion of the VIII cranial nerve. Evidence of normal cochlear outer hair cell function was provided by preservation of otoacoustic emissions and cochlear microphonics in all of the patients. Auditory brainstem potentials showed evidence of abnormal auditory pathway function beginning with the VIII nerve: the potentials were absent in nine patients and severely distorted in one patient. Auditory brainstem reflexes (middle ear muscles; crossed suppression of otoacoustic emissions) were absent in all of the tested patients. Behavioural audiometric testing showed a mild to moderate elevation of pure tone threshold in nine patients. The extent of the hearing loss, if due to cochlear receptor damage, should not have resulted in the loss of auditory brainstem potentials. The shape of the pure tone loss varied, being predominantly low frequency in five patients, flat across all frequencies in three patients and predominantly high frequency in two patients. Speech intelligibility was tested in eight patients, and in six was affected out of proportion to what would have been expected if the pure tone loss were of cochlear origin. The patients were otherwise neurologically normal when the hearing impairment was first manifest. Subsequently, eight of these patients developed evidence for a peripheral neuropathy. The neuropathy was hereditary in three and sporadic in five. We suggest that this type of hearing impairment is due to a disorder of auditory nerve function and may have, as one of its causes, a neuropathy of the auditory nerve, occurring either in isolation or as part of a generalized neuropathic process.

Adolescent↗

PubMed1991

Absence of both auditory evoked potentials and auditory percepts dependent on timing cues.

An 11-yr-old girl had an absence of sensory components of auditory evoked potentials (brainstem, middle and long-latency) to click and tone burst stimuli that she could clearly hear. Psychoacoustic tests revealed a marked impairment of those auditory perceptions dependent on temporal cues, that is, lateralization of binaural clicks, change of binaural masked threshold with changes in signal phase, binaural beats, detection of paired monaural clicks, monaural detection of a silent gap in a sound, and monaural threshold elevation for short duration tones. In contrast, auditory functions reflecting intensity or frequency discriminations (difference limens) were only minimally impaired. Pure tone audiometry showed a moderate (50 dB) bilateral hearing loss with a disproportionate severe loss of word intelligibility. Those auditory evoked potentials that were preserved included (1) cochlear microphonics reflecting hair cell activity; (2) cortical sustained potentials reflecting processing of slowly changing signals; and (3) long-latency cognitive components (P300, processing negativity) reflecting endogenous auditory cognitive processes. Both the evoked potential and perceptual deficits are attributed to changes in temporal encoding of acoustic signals perhaps occurring at the synapse between hair cell and eighth nerve dendrites. The results from this patient are discussed in relation to previously published cases with absent auditory evoked potentials and preserved hearing.

Acoustic Stimulation↗

PubMed1987

Induced temporary threshold shift in guinea pigs.

The etiology of an incidentally discovered temporary threshold shift observed in an experimental animal (Harley guinea pig) is discussed with its potential implications for auditory research.

Animals↗