Search

Background: Examination of cochlear and neural potentials is necessary to assess sensory and neural status in infants, especially those cared for in neonatal intensive care units (NICU) who have high rates of hyperbilirubinemia and thus are at risk for auditory neuropathy (AN). Purpose: The purpose of this study was to determine whether recording parameters commonly used in click-evoked auditory brain stem response (ABR) are useful for recording cochlear microphonic (CM) and Wave I in infants at risk for AN. Specifically, we analyzed CM, summating potential (SP), and Waves I, Ill, and V. The overall aim was to compare latencies and amplitudes of evoked responses in infants cared for in NICUs with infants in a well-baby nursery (WBN), both of which passed newborn hearing screening. Research Design: This is a prospective study in which infants who passed ABR newborn hearing screening were grouped based on their birth history (WBN and NICU). All infants had normal hearing status when tested with diagnostic ABR at about one month of age, corrected for prematurity. Study Sample: Thirty infants (53 ears) from the WBN [mean corrected age at test = 5.0 weeks (wks.)] and thirty-two infants (59 ears) from the NICU (mean corrected age at test = 5.7 wks.) with normal hearing were included in this study. In addition, two infants were included as comparative case studies, one that was diagnosed with AN and another case that was diagnosed with bilateral sensorineural hearing loss (SNHL). Data Collection and Analysis: Diagnostic ABR, including click and tone-burst air- and bone-conduction stimuli were recorded. Peak Waves I, Ill, and V; SP; and CM latency and amplitude (peak to trough) were measured to determine if there were differences in ABR and electrocochleography (ECochG) variables between WBN and NICU infants. Results: No significant group differences were found between WBN and NICU groups for ABR waveforms, CM, or SP, including amplitude and latency values. The majority (75%) of the NICU group had hyperbilirubinemia, but overall, they did not show evidence of effects in their ECochG or ABR responses when tested at about one-month corrected age. These data may serve as a normative sample for NICU and well infant ECochG and ABR latencies at one-month corrected age. Two infant case studies, one diagnosed with AN and another with SNHL demonstrated the complexity of using ECochG and otoacoustic emissions to assess the risk of AN in individual cases. Conclusions: CM and SPs can be readily measured using standard click stimuli in both well and NICU infants. Normative ranges for latency and amplitude are useful for interpreting ECochG and ABR components. Inclusion of ECochG and ABR tests in a test battery that also includes otoacoustic emission and acoustic reflex tests may provide a more refined assessment of the risks of AN and SNHL in infants. [ABSTRACT FROM AUTHOR]

Background: Children referred to audiology services with otherwise unexplained academic, listening, attention, language, or other difficulties are often found to be audiometrically normal. Some of these children receive further evaluation for auditory processing disorder (APD), a controversial construct that assumes neural processing problems within the central auditory nervous system. This study focuses on the evaluation of APD and how it relates to diagnosis in one large pediatric audiology facility. Purpose: To analyze electronic records of children receiving a central auditory processing evaluation (CAPE) at Cincinnati Children's Hospital, with a broad goal of understanding current practice in APD diagnosis and the test information which impacts that practice. Research Design: A descriptive, cross-sectional analysis of APD test outcomes in relation to final audiologist diagnosis for 1,113 children aged 5-19 yr receiving a CAPE between 2009 and 2014. Results: Children had a generally high level of performance on the tests used, resulting in marked ceiling effects on about half the tests. Audiologists developed the diagnostic category "Weakness" because of the large number of referred children who clearly had problems, but who did not fulfill the AAA/ASHA criteria for diagnosis of a "Disorder." A "right-ear advantage" was found in all tests for which each ear was tested, irrespective of whether the tests were delivered monaurally or dichotically. However, neither the side nor size of the ear advantage predicted the ultimate diagnosis well. Cooccurrence of CAPE with other learning problems was nearly universal, but neither the number nor the pattern of cooccurring problems was a predictor of APD diagnosis. The diagnostic patterns of individual audiologists were quite consistent. The number of annual assessments decreased dramatically during the study period. Conclusions: A simple diagnosis of APD based on current guidelines is neither realistic, given the current tests used, nor appropriate, as judged by the audiologists providing the service. Methods used to test for APD must recognize that any form of hearing assessment probes both sensory and cognitive processing. Testing must embrace modern methods, including digital test delivery, adaptive testing, referral to normative data, appropriate testing for young children, validated screening questionnaires, and relevant objective (physiological) methods, as appropriate. Audiologists need to collaborate with other specialists to understand more fully the behaviors displayed by children presenting with listening difficulties. To achieve progress, it is essential for clinicians and researchers to work together. As new understanding and methods become available, it will be necessary to sort out together what works and what doesn't work in the clinic, both from a theoretical and a practical perspective. [ABSTRACT FROM AUTHOR]

Background: Otosclerosis is a progressive middle-ear disease that affects conductive transmission through the middle ear. Ear-canal acoustic tests may be useful in the diagnosis of conductive disorders. This study addressed the degree to which results from a battery of ear-canal tests, which include wide-band reflectance, acoustic stapedius muscle reflex threshold (ASRT), and transient evoked otoacoustic emissions (TEOAEs), were effective in quantifying a risk of otosclerosis and in evaluating middle-ear function in ears after surgical intervention for otosclerosis. Purpose: To evaluate the ability of the test battery to classify ears as normal or otosclerotic, measure the accuracy of reflectance in classifying ears as normal or otosclerotic, and evaluate the similarity of responses in normal ears compared with ears after surgical intervention for otosclerosis. Research Design: A quasi-experimental cross-sectional study incorporating case control was used. Three groups were studied: one diagnosed with otosclerosis before corrective surgery, a group that received corrective surgery for otosclerosis, and a control group. Study Sample: The test groups included 23 ears (13 right and 10 left) with normal hearing from 16 participants (4 male and 12 female), 12 ears (7 right and 5 left) diagnosed with otosclerosis from 9 participants (3 male and 6 female), and 13 ears (4 right and 9 left) after surgical intervention from 10 participants (2 male and 8 female). Data Collection and Analysis: Participants received audiometric evaluations and clinical immittance testing. Experimental tests performed included ASRT tests with wideband reference signal (0.25-8 kHz), reflectance tests (0.25-8 kHz), which were parameterized by absorbance and group delay at ambient pressure and at swept tympanometric pressures, and TEOAE tests using chirp stimuli (1-8 kHz). ASRTs were measured in ipsilateral and contralateral conditions using tonal and broadband noise activators. Experimental ASRT tests were based on the difference in wideband-absorbed sound power before and after presenting the activator. Diagnostic accuracy to classify ears as otosclerotic or normal was quantified by the area under the receiver operating characteristic curve (AUC) for univariate and multivariate reflectance tests. The multivariate predictor used a small number of input reflectance variables, each having a large AUC, in a principal components analysis to create independent variables and followed by a logistic regression procedure to classify the test ears. Results: Relative to the results in normal ears, diagnosed otosclerosis ears more frequently showed absent TEOAEs and ASRTs, reduced ambient absorbance at 4 kHz, and a different pattern of tympanometric absorbance and group delay (absorbance increased at 2.8 kHz at the positive-pressure tail and decreased at 0.7-1 kHz at the peak pressure, whereas group delay decreased at positive and negative-pressure tails from 0.35-0.7 kHz, and at 2.8-4 kHz at positive-pressure tail). Using a multivariate predictor with three reflectance variables, tympanometric reflectance (AUC 5 0.95) was more accurate than ambient reflectance (AUC 5 0.88) in classifying ears as normal or otosclerotic. Conclusions: Reflectance provides a middle-ear test that is sensitive to classifying ears as otosclerotic or normal, which may be useful in clinical applications. [ABSTRACT FROM AUTHOR]