摘要:

ObjectiveVestibular evoked myogenic potential (VEMP) has recently been broadly studied in cochleo-vestibular disorders to elucidate its mechanism. Because it is evoked by loud sound stimulation, impairment of the sound transmission through the middle ear may affect VEMP results. This study aims to compare the response rate of VEMPs using the tone burst method and the tapping method in patients with chronic otitis media (COM).DesignFourteen patients (22 ears) with conductive hearing loss due to COM were subjected to VEMP tests using both the tone burst method and the tapping method. Each ear was stimulated by a short-tone burst (95 dB nHL, 500 Hz), followed by tapping on the forehead with a tendon hammer, 200 times at a frequency of 5 Hz.ResultsThirteen (59%) of the 22 ears showed positive VEMPs using the tone burst method, whereas 20 ears (91%) displayed positive VEMPs by the tapping method (p< 0.05). The latencies of wave p13 and n23, and the amplitude p13-n23 using the tone burst method were 13.4 ± 4.1 msec, 20.5 ± 4.6 msec, and 77.2 ± 17.2 &mgr;V, respectively. These results do not significantly differ from those obtained using the tapping method. In ears with perforated eardrums (N= 11), five ears (45%) displayed positive VEMPs by the tone burst method; compared with nine ears (82%) with positive VEMPs using the tapping method, representing a nonsignificant difference. In ears with healed eardrums (N= 11), eight ears exhibited positive VEMPs by tone burst, with a mean air-bone gap of 25.6 ± 15.2 dB at 500 Hz, in contrast to a gap of 30.0 ± 22.9 dB in three ears without VEMPs, indicating no significant difference.ConclusionsWhen stimulating sound is attenuated by middle ear pathology, VEMPs are expected to be poorly elicited. Under such conditions, myogenic potentials may be evoked with the tapping method to elicit the absent VEMPs that result from middle ear or inner ear pathology.

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveVestibular evoked myogenic potential (VEMP) has become a diagnostic tool to evaluate the integrity of sacculo-collic reflex. To obtain a more consistent VEMP response in normal-hearing subjects, we examine whether clicks or short tone bursts are more effective in eliciting VEMP responses.DesignProspective study. Twenty-nine normal-hearing volunteers (58 ears) were given VEMP tests. Clicks and short tone bursts were presented alternately to evoke VEMPs. The latencies of peak p13 and n23, peak-to-peak interval and amplitude (p13-n23) were measured and compared.ResultsClick stimulation of 57 ears (98%) produced VEMPs (C-VEMPs), whereas 51 (88%) revealed positive short tone burst-evoked VEMPs (STB-VEMPs), exhibiting a significant difference (p< 0.05). Furthermore, C-VEMPs displayed shorter latency, longer interval and larger amplitude than STB-VEMPs, with a significant difference (p< 0.05), respectively.ConclusionsC-VEMPs had a higher response rate, shorter latency, and larger amplitude than STB-VEMPs. These findings suggest that click is superior to short tone burst to trigger VEMPs. Because C-VEMPs have a shorter p13 latency than STB-VEMPs, the interpretation of prolonged latency differs in each stimulus condition.

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveThe purpose of this study was to characterize the sensorineural hearing losses of a group of children and adults along three parameters important to the hearing instrument fitting process: 1) audiometric configuration, 2) asymmetry of loss between ears, and 3) progression of loss over several years.DesignAudiograms for 248 60- and 61-yr-old adults and 227 6-yr-old children were obtained from the audiological database at Boys Town National Research Hospital. Based on right-ear air-conduction thresholds, the configurations were assigned to one of six categories: sloping, rising, flat, u-shaped, tent-shaped, and other. Left- and right-ear thresholds were compared to determine asymmetry of loss. Progression of loss was evaluated for 132 children for whom additional audiograms over an 8-yr period were available.ResultsIn general, the children's hearing losses were more evenly distributed across configuration categories while most of the adult's audiograms were sloping or u-shaped in configuration. The variability of loss at each frequency was greater for the children than the adults for all configuration categories. Asymmetrical losses were more common and the degree of asymmetry at each frequency was more extensive among the children than the adults. A small number of children showed either improved or deteriorated hearing levels over time. In those children for whom progressive hearing loss occurred, no frequency was more vulnerable than another.ConclusionsThe results of the present study suggest that substantial differences in audiological characteristics exist between children and adults. Implications for amplification include the development of appropriate fitting protocols for unusual audiometric configurations as well as protocols for binaural amplification in cases of asymmetric hearing losses.

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo study a controversy that has been discussed for more than two decades: whether or not children with autism have abnormalities affecting the cochlear nerve or the auditory pathway in the brain stem and, if so, to describe these abnormalities.DesignA group of 153 children and adolescents with autistic disorder were included in an investigation of auditory brain stem responses (ABR). Two thirds of this group, 101 individuals (75 boys, 26 girls), had normal hearing and they were selected for an in-depth ABR study. The results from the study group were compared with those of an age-matched comparison group.ResultsThe III-V interpeak latency (IPL) was significantly prolonged in both boys and girls with autism, compared with the controls. The latencies of ABR waves I and V were also significantly lengthened in the study groups. The individual test results showed that more than half of this normal-hearing autistic disorder group (58%) had abnormalities of one or more of eight ABR parameters studied. The most common abnormalities were prolongation of wave V (38%), and of I-V IPL (28%). A lengthening of the I-V IPL was also recorded in 27% of 49 children who were difficult to test or who had hearing loss. Abnormal left–right differences of ABR latencies were found in 18% of autism cases with normal hearing.ConclusionsPossible causes of the reported ABR abnormalities, observed here as well as in other studies, are discussed. Brain stem lesion, occult cochlear dysfunction, and involvement of the cochlear efferent system are probable factors that can explain the ABR findings

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveThe purpose of this study was to determine whether the label attached to the hearing aid being presented would bias outcome measures towards newer technological designs.DesignTwo groups of subjects participated in this investigation. The groups were matched for age, gender, previous hearing aid experience, degree and configuration of hearing loss. Group A wore each of two digital hearing aids for 1 mo; Group B wore the same digital hearing aid for 2 mo, but the subjects were given the impression they were changing hearing aids after 1 mo. In each group the subjects were told that one of the months they were wearing a “digital” hearing aid and one of the months they were wearing a “conventional” hearing aid. Outcome measures consisted of a number of behavioral speech perception tasks and self-report measures, each completed at the onset and after 1 mo use with the hearing aids.ResultsLabeling effects were observed for many of the outcome measures. Using a mixed-model factorial analysis of variance to control for irrelevant variables and to explore interaction terms, prejudice (digital versus conventional labeling) was treated as a within-subject factor while the subject group (A or B) and clinician were treated as between-subject factors. Although only the APHAB RV and BN scales showed significant labeling effects on their own, the group of tests used in this study showed a significant labeling effect as a whole (p< 0.01). The total influence of labeling and related interaction terms indicated labeling-related effects accounted for 2 to 32% of the variance in individual outcome measures.DiscussionThe results of this investigation indicate a need for double-blinding in hearing aid research aimed at assessing the effectiveness of newer technologies, as well as a need for clinicians to critically evaluate the research describing the potential advantages of certain circuit options.

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo determine if naturally produced speech stimuli evoke distinct neural response patterns that can be reliably recorded in individuals.DesignAuditory cortical evoked potentials were obtained from seven normal-hearing young adults in response to four naturally produced speech tokens (/bi/, /pi/, /&U0283;i/, and /si/). Stimuli were tokens from the standardized UCLA version of the Nonsense Syllable Test (NST) (Dubno & Schaefer, 1992). Using a repeated measures design, subjects were tested and then retested within an 8-day period.ResultsAuditory cortical evoked potentials elicited by naturally produced speech sounds were reliably recorded in individuals. Also, naturally produced speech tokens, representing different acoustic cues, evoked distinct neural response patterns.Conclusions1) Cortical evoked potentials elicited by naturally produced speech sounds can be reliably recorded in individuals. 2) Naturally produced speech tokens, representing different acoustic cues, evoke distinct neural response patterns. 3) Given the reliability of the response, this work has potential application to the study of neural processing of speech in individuals with communication disorders as well as changes over time after various types of auditory rehabilitation.

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo assess the diagnostic utility of anti-hsp70 antibody screening in sudden deafness.DesignSera from 27 patients with sudden deafness and 100 healthy blood donors were analyzed by Western blotting (WB) for the presence of antibodies against 68 kD heat shock protein (anti-hsp70).Results19% of the patient sera and 14% of the control sera turned out positive, which was not significantly different.ConclusionsThe anti-hsp70 WB test lacks clinical utility for diagnostic screening in patients with sudden deafness.

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveThe principal goal of this study was to investigate the relationship between language and literacy (i.e., reading and writing) skills in pediatric cochlear implant users. A peripheral objective was to identify the children's skills that were in need of remediation and subsequently to provide suggestions for remedial programming. It was predicted that the robust language skills often associated with children who have cochlear implant experience would facilitate the development of literacy skills. It was further proposed that the language and literacy skills of pediatric cochlear implant users would approximate the language and literacy skills of children with normal hearing.DesignSixteen pediatric cochlear implant users’ language and literacy skills were evaluated and then compared with a reference group of 16 age-matched, normal-hearing children. All 32 participants were educated in mainstream classes within the public school system in the Midwest. The “Sentence Formulation” and “Concepts and Directions” subtests of theClinical Evaluation of Language Fundamentals-3test were used to evaluate receptive and expressive language skills. Reading comprehension was evaluated with the “Paragraph Comprehension” subtest of theWoodcock Reading Mastery Test. Performance measures for the writing analyses included productivity, complexity and grammaticality measures.ResultsChildren with cochlear implants performed within 1 SD of the normal-hearing, age-matched children on measures of language comprehension, reading comprehension and writing accuracy. However, the children with cochlear implants performed significantly poorer than the children with normal hearing on the expressive “Sentence Formulation” subtest. The cochlear implant users also produced fewer words on the written narrative task than did the normal-hearing children, although there was not a significant difference between groups with respect to total words per clause. Furthermore there was a strong correlation between language performance and reading performance, as well as language performance and total words produced on the written performance measure for the children using cochlear implants.ConclusionsThe results of this study suggest that the language skills of pediatric cochlear implant users are related to and correlated with the development of literacy skills within these children. Consequently, the performance of the cochlear implant users, on various language and literacy measures, compared favorably to an age-matched group of children with normal hearing. There were significant differences in the ability of the cochlear implant users to correctly utilize grammatical structures such as conjunctions and correct verb forms when they were required to formulate written and oral sentences. Given this information, it would be appropriate for their educational or remedial language programs to emphasize the use and development of these structures.

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveThe purpose of this study was to acquire the Binaural Interaction (BI) components of the auditory middle-latency steady-state 40 Hz potentials, compare them with those of the binaurally evoked 40 Hz response and with transient-evoked Auditory Middle Latency Evoked Potentials (AMEP) and suggest possible contributors and generators of the composite 40 Hz BI.MethodsPotentials were recorded from 15 normal-hearing adults in response to 40/sec clicks. BI was derived by subtracting the binaurally evoked potentials from the algebraic sum of the evoked potentials to left and to right ear stimulation. Latencies, magnitudes and orientations of the dipole equivalents of 40 Hz components were compared with their BI counterparts, as estimated by three-channel Lissajous’ trajectories. Comparison of the transient AMEP to binaural stimulation with the BI of the steady-state 40 Hz response was also conducted to elucidate the contributions of different levels along the auditory pathway to the 40 Hz BI responses.ResultsEach cycle of the BI of the steady-state 40 Hz AMEP included four components that corresponded in latency, amplitude, and dipole orientation to their counterparts in the binaurally evoked waveform. Amplitudes of BI components were 50 to 60% of the respective values in the binaurally evoked potentials. Orientations of BI components matched those of the cortical components in the transient-evoked AMEP.ConclusionsThe results suggest that the main contribution to the 40 Hz BI is from rate resistant thalamo-cortical neurons. The results also suggest that the binaural cortical neurons contributing to the 40 Hz BI are less affected by increased rate than monaural neurons.

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0196-0202    

出版商:OVID    

年代:2003

数据来源: OVID