Auditory Deficits in Patients With Mild and Moderate Obstructive Sleep Apnea Syndrome: A Speech Syllable Evoked Auditory Brainstem Response Study

OBJECTIVES: The energy consumption process of cochlea and neural signal transduction along the auditory pathway are highly dependent on blood oxygen supply. At present, it is under debate on whether the obstructive sleep apnea syndrome (OSAS) would affect the auditory function since the patients suffer from low oxygen saturation. Moreover, it is difficult to detect the functional state of auditory in less severe stage of OSAS. Recently, speech-evoked auditory brainstem response (speech-ABR) has been reported to be a new electrophysiological tool in characterizing the auditory dysfunction. The aim of the present study is to evaluate the auditory processes in adult patients with mild and moderate OSAS by speech-ABR. METHODS: An experimental group of 31 patients with mild to moderate OSAS, and a control group without OSAS diagnosed by apnea hypopnea index in polysomnogram were recruited. All participants underwent otologic examinations and tests of pure-tone audiogram, distortion product otoacoustic emissions, click-evoked auditory brainstem response (click-ABR) and speech-ABR, respectively. RESULTS: The results of pure-tone audiogram, distortion product otoacoustic emissions, and click-ABR in OSAS group showed no significant differences compared with the control group (P>0.05). Speech-ABRs for OSAS participants and controls showed similar morphological waveforms and typical peak structures. There were significant group differences for the onset and offset transient peaks (P < 0.05), where OSAS group had longer latencies for peak V (6.69± 0.33 ms vs. 6.39±0.23 ms), peak C (13.48±0.30 ms vs. 13.31±0.23 ms), and peak O (48.27±0.39 ms vs. 47.60± 0.40 ms) compared to the control group. The latency of these peaks showed significant correlations with apnea hypopnea index for peak V (r=0.37, P=0.040), peak C (r=0.36, P=0.045), as well as peak O (r=0.55, P=0.001). CONCLUSION: These findings indicate that some auditory dysfunctions may be present in patients with mild and moderate OSAS, and the damages were aggravated with the severity of OSAS, which suggests that speech-ABR may be a potential biomarker in the diagnosis and evaluation at early stage of OSAS.

Noise attenuation analysis on auditory evoked potential based on maximum length sequence / 生物医学工程学杂志

The maximum length sequence (m-sequence) has been successfully used to study the linear/nonlinear components of auditory evoked potential (AEP) with rapid stimulation. However, more study is needed to evaluate the effect of the m-sequence order in terms of the noise attenuation performance. This study aimed to address this issue using response-free electroencephalogram (EEG) and EEGs with nonlinear AEPs. We examined the noise attenuation ratios to evaluate the noise variation for the calculations of superimposed averaging and cross-correlation, respectively, which constitutes the main process in the deconvolution method using the dataset of spontaneous EEGs to simulate the cases of different orders (order 5 to 12) of m-sequences. And an experiment using m-sequences of order 7 and 9 was performed in true cases with substantial linear and nonlinear AEPs. The results demonstrate that the noise attenuation ratio is well agreed with the theoretical value derived from the properties of m-sequences on the random noise condition. The comparison of waveforms for AEP components from two m-sequences showed high similarity suggesting the insensitivity of AEP to the m-sequence order. This study provides a more comprehensive solution to the selection of m-sequences which will facilitate the feasible application on the nonlinear AEP with m-sequence method.

The Protective Effects of Intratympanic Dexamethasone to Prevent Cisplatin Ototoxicity / 听力学及言语疾病杂志

Objective To investigate the effectiveness of intratympanic dexamethasone injection as a protec-tion agent against cisplatin ototoxicity.Methods Fifty five healthy guinea pigs were randomly divided into four groups.The guinea pigs groups received (group I)0.9% NaCl solution(16 ml/kg)intraperitoneally (IP),(group II)dexamethasone (10 mg/ml)intratympanically(IT),(group III)cisplatin (16 mg/kg)only intraperitoneally(IP) and (group IV)dexamethasone (10 mg/ml)IT followed after 1h by 16 mg/kg cisplatin.Before and 7 days following injections,the ototoxic effect was measured with auditory brainstem response(ABR).The contents of malondiade-hyde(MDA)and activities of superoxide dismutase(SOD)were also measured.Results ABR thresholds before and after dosing were 28.50±4.74,29.00±3.94 dB nHL and 28.67±5.82,31.33±5.81 dB nHL in group I and group II,respectively,with no significant differences (P>0.05).The contents of MDA and activities of SOD were 2.01 ±0.07 mmol/L ,234.10±13.09 U/ml and 2.06±0.09 mmol/L,233.20±13.24 U/ml in the group I and group II, respectively,with no significant differences (P>0.05).ABR thresholds after dosing were 55.33±4.81,and 40.67 ±3.72 dB nHL in the group III and group IV,which were significantly increased,but ABR thresholds in the group IV were significantly lower than that in the group III (P<0.05).The contents of MDA were 5.74±0.17,3.51± 0.18 mmol/L in the group III and group IV,which were significantly increased.SOD activities were 107.90 ± 14.21,and 162.70±11.25 U/ml,which significantly decreased.Nevertheless,in the group IV dexamethasone rela-tively reduced the contents of MDA(P<0.001)while increased the activities of SOD(P<0.001)compared with group III.Conclusion Intratympanic dexamethasone injection presents as an effective treatment modality to prevent cisplatin ototoxicity without any ototoxic effect.

Relationships between electrophysiological characteristic of speech evoked auditory brainstem response and mandarin monosyllable discriminative ability / 中国耳鼻咽喉头颈外科

[ABSTRACT]OBJECTIVETo investigate the relationships between electrophysiological characteristic of speech evoked auditory brainstem response and Mandarin phonetically balanced maximum, so as to provide more clues for the mechanism of speech cognitive behavior. METHODSThe speech discrimination scores were obtained by Mandarin phonemic-balanced monosyllable lists via speech audiometric software in forty-one ears of normal hearing adults. Their s-ABRs were recorded with speech syllables da with the intensity of phonetically balanced maximum (PBmax). The electrophysiological characteristic of s-ABR, as well as the relationships between PBmax and s-ABR parameters including latency in time domain, fundamental frequency (F0) and first formant (F1) in frequency domain were analyzed statistically.RESULTS While divided the subjects into three groups by PBmax1= 100%, 100%

Effectiveness of cisplatin on the expressions of Bcl-2 and Bax in cochlea and spiral ganglion cells of guinea pigs / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the effectiveness of cisplatin on the expressions of Bcl-2 and Bax in cochlea and spiral ganglion cells (SGC) of guinea pigs.@*METHOD@#Twenty guinea pigs were randomly divided into cisplatin (n = 10) and control groups (n = 10). Cisplatin group were administrated with a dose of intraperitoneal injection of 16 mg/kg, while the control group were received intraperitoneal injection of normal saline as placebo. Before and 7 days following injections, the ototoxic effect was measured with distortion product otoacoustic emission (DPOAE). Bcl-2, Bax in cochlea were detected by Western Blot. Immunohistochemical staining was used to detect the protein levels of Bcl-2 and Bax in spiral ganglion cells.@*RESULT@#In control and cisplatin group, Bcl-2 protein levels were 0.727 8 ± 0.016 9 and 0.467 6 ± 0.020 1, Bax protein levels were 0.384 8 ± 0. 0217 and 0.735 6 ± 0.022 3 in cochlea respectively, both P < 0.01. In Control and cisplatin group, the grey values of Bcl-2 in SGC were 99.00 ± 2.42 and 149.80 ± 2.37 respectively, the grey values of Bax were 154.50 ± 2.80 and 104.50 ± 3.09 respectively, both P < 0.05.@*CONCLUSION@#Decreased expression of Bcl-2 and increased expression of Bax may be involved in cisplatin-induced apoptosis in cochlea and SGC of guinea pigs.

Relationships of electrophysiological characteristic between speech evoked auditory brainstem response and auditory mismatch negativity / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the relationships of electrophysiological characteristics between speech evoked auditory brainstem response (s-ABR) and auditory mismatch negativity (MMN), so as to provide more clues for the mechanism of speech cognitive behavior.@*METHOD@#Thirty-three ears in 33 normal hearing adults were included in this study. Their s-ABR were recorded with speech syllables /da/ at 80 dB HL intensity. Meanwhile, two MMNs were recorded with 1 kHz frequency deviant extent and 40 dB intensity deviant extent in them. The electrophysiological characteristics of s-ABRs and MMNs, as well as the relationships of MMN latencies between s-ABR parameters including latencies in time domain, fundamental frequency(F0) and first formants(F1) in frequency domain were analyzed statistically.@*RESULT@#MMN latency of frequency deviance showed a negative correlation tendency with s-ABR transient components, and it showed a positive trend with sustained components of s-ABR. While MMN latency of intensity deviance showed a positive correlation with s-ABR latency of peak V, A and D respectively, and it negatively showed a correlation with s-ABR latency of other peak s and amplitude of F0 and FI respectively. Only the s-ABR latency of peak F and MMN latency of frequency deviance, and the F0 amplitude of s-ABR and MMN latency of intensity deviance were moderate correlation statistically.@*CONCLUSION@#It was probably the neurons of frequency deviant MMN unmatched the characteristics of frequency with the neurons of s-ABR transient component, but well matched the characteristics of frequency with the neurons of s-ABR sustained component. Similarly, the neurons of intensity deviant MMN probably matched the characteristics of intensity with neurons of different components of s-ABR or not. These results may formed as a valuable clue for further investigation of speech perception and temporal processing abilities.

The effectiveness of endoscopic tragus cartilage-perichondrium myringoplasty in the treatment of large tympanic membrane perforations / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To evaluate effectiveness of endoscopic tragus cartilage-perichondrium in the treatment of large tympanic membrane perforations.@*METHOD@#Patients with large tympanic membrane perfortations who had underwent cartilage-perichondrium myringoplasty were retrospectively retrieved from our department. Those with a follow-up of equal to or greater than 12 months after surgery were included in the study. Hearing test results were reported using a four-frequency air conduction and bone-air conduction gap. Patients were labeled as treatment success if the tympanic membrane was intact without lateralization or anterior blunting after surgery.@*RESULT@#Of the 35 patients with large tympanic membrane perforations treated by endoscopic tragus cartilage-perichondrium, 33 (94.3%) were treatment success. There was no graft lateralization, anterior blunting, neocholesteatoma, and sensorineural hearing loss in these patients after surgery. The air conduction and bone-air conduction gap before surgery in the study cohort were (43.8 ± 5.7) dB and (28.5 ± 3.1) dB, respectively. Postoperative air conduction and bone-air conduction gap of the cohort were (31.4 ± 6.4) dB HL and (16.2 ± 4.1) dB, respectively. The postoperative air conduction and bone-air conduction gap decreased significantly after surgery (P < 0.01). Overall postoperative air-bone gap in 27 of the 35 patients (77%) were less than 20 dB after surgery.@*CONCLUSION@#Endoscopic cartilage-perichondrium myringoplasty is an effective procedure in the treatment of large tympanic membrane perforations.

Efficacy of intratympanic dexamethasone combined with prednisone on idiopathic sudden sensorineural hearing loss / 实用医学杂志

Objective To evaluate the therapeutic efficacy of intratympanic dexamethasone injections combined with prednisone in patients with idiopathic sudden sensorineural hearing loss. Methods A total of 71 patients diagnosed with sudden hearing loss were treated with intratympanic dexamethasone injections plus prednisone (B group) or prednisone alone (A group). Hearing was evaluated by pure tone audiogram performed before initial treatment and at 4 weeks following the final treatment. Results The total recovery rate after the treatment was 81.8% in the B group and 55.3% in the A group. The diflference between two groups was statistically significant (P < 0.05). Conclusion The present study suggests that sudden sensorineural hearing loss patients treated with intratympanic dexamethasone combined with prednisone have a higher likelihood of hearing recovery than those treated with prednisone alone.

Instantaneous energy spectrum analysis for frequency following response of speech evoked brainstem response / 生物医学工程学杂志

Speech evoked brainstem responses (s-ABRs) elicited by a speech syllable /da/ are composed of four parts: onset response (OR), transitional response, frequency following response (FFR) and offset response. FFR elicited by periodic events behaves like a quasi-periodic waveform corresponding to the stimulus sounds. The fast Fourier transform based spectra are commonly used to exam the characteristics of s-ABR in practice, which is, however, unable to trace the occurrence of the main components of s-ABR. The FFR is usually not obvious in the original individual s-ABR waveform. In this paper, we proposed a novel approach to observe the FFR by an instantaneous energy spectrum performed on the intrinsic mode functions (IMFs) after empirical mode decomposition (EMD) of the s-ABR. We demonstrated that the FFR is most pronounced on the second layer of IMFs. This finding suggests a new way which may be available to characterize and to detect the FFR better. This will benefit the clinic applications of s-ABRs.

Comparison of auditory brainstem responses to speech from bilateral ears with ipsilateral recordings / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To compare the time domain and the frequency domain of speech-evoked auditory brain-stem response measured by stimulation of left and right ears, and to explore the difference and possible reasons of neural coding for speech from different ears in auditory brainstem.@*METHOD@#Speech-ABRs to syllable /da/ of 31 healthy adults were recorded. Statistical analysis was performed on time-domain parameters, such as latencies and amplitudes of featured peaks, and frequency-domain ones, such as amplitudes of the fundamental frequency and the first formant of speech-ABRs ranging from 20-50 ms. A scoring criterion to grade the appearance of featured waves was proposed for waveform evaluation.@*RESULT@#There were no significant difference for the latencies of binaural featured peaks and amplitudes of feature peaks (except peaks A and O). The waveform .scores of right ear were greater than that of left ear. The amplitudes of fundamental frequency of binaural waves were both greater than that of the first formant. There was no significant difference of amplitudes of fundamental frequency and the first formant between two ears.@*CONCLUSION@#The origins and distributions of speech-ABR are essentially symmetrical in brainstem in contrast with the hemisphere asymmetry of speech.

Comparison of the efficiency of techniques for deconvolving auditory-evoked potentials with high rate stimulation / 生物医学工程学杂志

In some auditory evoked potential (AEP) examinations, high rate stimulation paradigms deliver more stimuli with the same period of time, which might lead to overlapping responses. At present, several established techniques can be proposed to address such problem, thus the research scope in both scientific and clinical applications is expanded. In this study, the restoring efficiency of evoked responses is investigated using a simulation strategy. We examined the AEPs derived from three paradigms--conventional ensemble averaging, continuous loop averaging deconvolution (CLAD) and maximum length sequence (MLS). Their performances were evaluated by correlation coefficients and Euclidean distances between ideal and the derived responses. We found that MLS can only slightly enhance the performance at the cost of larger stimulus jitter and much more stimulus numbers; while CLAD method with lower jittering even degenerates the quality, suggesting that, in practical use, the recording efficiency will not be significantly improved by simply using high rate stimulation with overlapping responses introduced.

Research on the Stability of Speech-evoked Auditory Brainstem Response / 中国医学物理学杂志

Objective:To investigate the speech-evoked brainstem response (speech-ABR) of normal young people under different recording periods,which can provide the experimental evidences for researches on the stability of speech-ABR and promote its applications in clinical researches.Methods:40 healthy young people were randomly divided into two groups,which were tested following the same protocol at different time of two months interval.Latencies and amplitudes of the feature peaks in these groups were compared and the rates of appearance (detection rate) of the feature peaks were analyzed statistically.Results:Speech-ABRs were recorded successfully in two groups.The latencies and amplitudes of feature peaks in these groups were not different statistically,and the detection rates of V,A,C and F peaks were higher than others.Conclusion:The speech-ABRs of the two groups are stable,and the V,A,C and F peaks can be used as important indicators of clinical observation,showing that Speech-ABR is a promising tool in the study of Speech perception mechanism.

Comparison of auditory brainstem responses to speech from bilateral ears with ipsilateral recordings / 临床耳鼻咽喉头颈外科杂志

Objective:To compare the time domain and the frequency domain of speech-evoked auditory brainstem response measured by stimulation of left and right ears, and to explore the difference and possible reasons of neural coding for speech from different ears in auditory brainstem.Method:Speech-ABRs to syllable /da/ of 31 healthy adults were recorded. Statistical analysis was performed on time-domain parameters, such as latencies and amplitudes of featured peaks, and frequency-domain ones, such as amplitudes of the fundamental frequency and the first formant of speech-ABRs ranging from 20-50 ms. A scoring criterion to grade the appearance of featured waves was proposed for waveform evaluation.Result:There were no significant difference for the latencies of binaural featured peaks and amplitudes of feature peaks(except peaks A and O). The waveform scores of right ear were greater than that of left ear. The amplitudes of fundamental frequency of binaural waves were both greater than that of the first formant. There was no significant difference of amplitudes of fundamental frequency and the first formant between two ears.Conclusion:The origins and distributions of speech-ABR are essentially symmetrical in brainstem in contrast with the hemisphere asymmetry of speech.

Latency characteristics of speech evoked auditory brainstem response / 中国耳鼻咽喉头颈外科

OBJECTIVE To explore the latency characteristics of speech evoked auditory brainstem response(speech-ABR)from healthy Chinese adults by different stimulation intensities and its significance in neural encoding of speech in the brainstem. METHODS ABRs to speech syllables of 32 subjects were recorded in four stimulus intensities varied from 20 to 80 dB SPL by 20 dB steps, under 11.1/s stimulus rate. A set of featured waves were determined under these intensities, and then the characteristics of their latencies were analyzed. RESULTS A series of featured waves were observed starting from onset response(including V and A waves), transitional C wave, then following frequency-following responses(FFRs), and the offset O wave. As the reduction of stimulus intensity, the latencies of speech-ABR delayed significantly(P