1.Auditory Rehabilitation in Rhesus Macaque Monkeys (Macaca mulatta) with Auditory Brainstem Implants.
Zhen-Min WANG ; Zhi-Jun YANG ; Fu ZHAO ; Bo WANG ; Xing-Chao WANG ; Pei-Ran QU ; Pi-Nan LIU ;
Chinese Medical Journal 2015;128(10):1363-1369
BACKGROUNDThe auditory brainstem implants (ABIs) have been used to treat deafness for patients with neurofibromatosis Type 2 and nontumor patients. The lack of an appropriate animal model has limited the study of improving hearing rehabilitation by the device. This study aimed to establish an animal model of ABI in adult rhesus macaque monkey (Macaca mulatta).
METHODSSix adult rhesus macaque monkeys (M. mulatta) were included. Under general anesthesia, a multichannel ABI was implanted into the lateral recess of the fourth ventricle through the modified suboccipital-retrosigmoid (RS) approach. The electrical auditory brainstem response (EABR) waves were tested to ensure the optimal implant site. After the operation, the EABR and computed tomography (CT) were used to test and verify the effectiveness via electrophysiology and anatomy, respectively. The subjects underwent behavioral observation for 6 months, and the postoperative EABR was tested every two weeks from the 1 st month after implant surgery.
RESULTThe implant surgery lasted an average of 5.2 h, and no monkey died or sacrificed. The averaged latencies of peaks I, II and IV were 1.27, 2.34 and 3.98 ms, respectively in the ABR. One-peak EABR wave was elicited in the operation, and one- or two-peak waves were elicited during the postoperative period. The EABR wave latencies appeared to be constant under different stimulus intensities; however, the amplitudes increased as the stimulus increased within a certain scope.
CONCLUSIONSIt is feasible and safe to implant ABIs in rhesus macaque monkeys (M. mulatta) through a modified suboccipital RS approach, and EABR and CT are valid tools for animal model establishment. In addition, this model should be an appropriate animal model for the electrophysiological and behavioral study of rhesus macaque monkey with ABI.
Animals ; Auditory Brain Stem Implants ; Deafness ; surgery ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Female ; Macaca mulatta ; Male
3.Limitation of High Pitch Sound Perception in Nontumor Patients with Auditory Brainstem Implantation.
Hyun Seung CHOI ; Jae Young CHOI ; In Seok MOON ; Mi Ran BAE ; Bo Gyung KIM ; Minbum KIM ; Jin Woo CHANG ; Junhui JEONG
Korean Journal of Otolaryngology - Head and Neck Surgery 2018;61(5):235-241
BACKGROUND AND OBJECTIVES: Auditory brainstem implantation (ABI) is another option for hearing rehabilitation in non-neurofibromatosis type 2 patients who cannot undergo cochlear implantation (CI). However, the average performance of ABI is worse than that of CI. We analyzed the psycho-electrical parameters of each electrode and psycho-acoustic response to different frequency sounds in nontumor patients with ABI. SUBJECTS AND METHOD: Sixteen patients with ABI from July 2008 to May 2013 were included in the study. They were followed up for 4 to 56 months. Among them, 12 were prelingual deaf with a narrow internal auditory canal or cochlear ossification. The remaining four were post-lingual deaf adults with severely ossified cochleae. We analyzed the electrical parameters [impedance, threshold level (T level), and dynamic range] of each of the 12 electrodes. We also evaluated the sound field pure-tone threshold, Ling 6 sound detection-identification test (Ling 6 test), and pitch ranking data of these patients. RESULTS: The impedance, T level, and dynamic range did not significantly differ among electrodes. However, the pure-tone threshold to sound field stimulation was elevated in the high tone area, where more variables were found than in the low frequency area. Patients could not identify /S/ and /Sh/ sounds in the Ling 6 test. The mean T level and the dynamic range of the three highest pitch-perceiving electrodes in each patient was higher and narrower, respectively, than those of the three lowest pitch-perceiving electrodes. CONCLUSION: The nontumor patients with ABI have difficulty perceiving high pitch sound. More sophisticated penetrating type electrodes and, if possible, bimodal stimulation with CI, could be considered.
Adult
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Auditory Brain Stem Implantation*
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Auditory Brain Stem Implants*
;
Cochlea
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Cochlear Implantation
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Cochlear Implants
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Electric Impedance
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Electrodes
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Hearing
;
Humans
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Methods
;
Rehabilitation
4.Development of electrically evoked auditory brainstem response modules of REZ-I domestic cochlear implant device.
Xiuyong DING ; Ruxiang ZHANG ; Changjian XU ; Wei FAN ; Daoxing ZHANG
Chinese Journal of Otorhinolaryngology Head and Neck Surgery 2014;49(12):1013-1016
OBJECTIVETo develop electrically evoked auditory brainstem response(EABR) modules of REZ-I domestic cochlear implant device, and testify the reliability and validity of the modules.
METHODSPostoperative EABR were recorded in guinea pigs by using the self-designed EABR module.
RESULTSEABR waves were recorded in all 15 ears of 9 guinea pigs with normal hearing. The threshold was (159.00 ± 50.21) current level (CL) and eIII wave latency was (2.36 ± 0.46) ms of 100 µs pulse width stimulation; for 150 µs pulse width stimulation, the threshold was (131.44 ± 49.25) CL and eIII wave latency was (2.59 ± 0.46)ms; for 200 µs pulse width stimulation, the threshold was (119.63 ± 52.56) CL and e III wave latency was (2.62 ± 0.44)ms.
CONCLUSIONAccording the preliminary results of the study, the reliability and stability of the EABR modules of domestic cochlear implant device can meet the demands of EABR recording.
Animals ; Auditory Threshold ; Cochlea ; Cochlear Implantation ; Cochlear Implants ; Evoked Potentials, Auditory, Brain Stem ; Guinea Pigs ; Reproducibility of Results
5.c-fos Immunoreactivity at the Auditory and Visual Cortex in Experimentally Induced Deafness in Guinea Pigs.
Yong Ho PARK ; Kang Oh LEE ; Soo Il KIM ; Jae Yong PARK ; Bon Seok KOO ; Yong Min KIM ; Ki Sang RHA
Korean Journal of Otolaryngology - Head and Neck Surgery 2008;51(7):602-608
BACKGROUND AND OBJECTIVES: Recently, functional studies for auditory cortex are being watched with interest in accordance with development of many radiologic equipments and surgical devices for sensorineural hearing loss. Moreover, it is well known that the function of central auditory pathway is essential for hearing rehabilitation. There are some papers that reported about the functional or metabolic changes of auditory cortex in deafness and in patients with cochlear implantation. The aim of this study was to investigate indirectly the metabolic changes of primary auditory cortex and visual cortex in the c-fos immunoreactivity in an experimentally induced permanent threshold shift animal model. MATERIALS AND METHOD: Ototoxic drugs (kanamycin and furosemide) and noise were used for the induction of permanent threshold shift. Cochlear damages were evaluated with auditory brainstem responses (ABR) and morphologic studies. The c-fos immunoreactivity was observed with a lapse of time after deafening. RESULTS: After the administration of ototoxic drugs and noise exposure, ABR threshold shifts were not recovered until after three months. Cochlear damages were observed in broad areas of cochlea. The c-fos immunoreactivity in the primary auditory cortex was increased during the acute period but it was decreased after one month. In addition, it was recovered again within the level of control three months later. In the visual cortex, increased and sustained immunoreactivities were observed after the drug and noise exposure. CONCLUSION: This result shows the plasticity of auditory cortex and possibility of some kinds of auditory-visual cross modal plasticity.
Animals
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Auditory Cortex
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Auditory Pathways
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Cochlea
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Cochlear Implantation
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Cochlear Implants
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Deafness
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Evoked Potentials, Auditory, Brain Stem
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Guinea
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Guinea Pigs
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Hearing
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Hearing Loss, Sensorineural
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Humans
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Noise
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Plastics
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Visual Cortex
6.Effects of Residual Hearing on the Auditory Steady State Response for Cochlear Implantation in Children
Young Seok KIM ; Sun A HAN ; Hyunjun WOO ; Myung Whan SUH ; Jun Ho LEE ; Seung Ha OH ; Moo Kyun PARK
Journal of Audiology & Otology 2019;23(3):153-159
BACKGROUND AND OBJECTIVES: We aim to explore the effects of residual auditory steady state response (ASSR) on cochlear implantation (CI) outcomes in children lacking auditory brainstem responses (ABRs). SUBJECTS AND METHODS: We retrospectively reviewed the data of child CI recipients lacking ABRs. All ears were divided into two groups: with residual ASSR and without ASSR. For each frequency, the T- and C-levels and the electrical dynamic ranges of postoperative 3-month and 1-year mappings were compared between the groups. To evaluate speech perception, patients who received simultaneous bilateral CIs were divided into two groups: group 1 exhibited responses at all frequencies in both ears; in group 2, at least one ear evidenced no response. The Categories of Auditory Perception (CAP) and Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) scores were compared between the groups. RESULTS: We enrolled 16 patients. At 2 kHz, the postoperative 3-month and 1-year T-levels of patients with residual hearing were lower than those of hearing loss group (p=0.001, p=0.035). In residual hearing group, the ASSR threshold correlated positively with the postoperative 1-year T-level (p=0.012, R² =0.276) and C-level (p=0.002, R² =0.374). Of 10 simultaneous bilateral CI recipients, 5 exhibited ASSRs at all frequencies and the other 5 showed no response at ≥1 frequency. The latter had higher CAP scores at the postoperative 1-year (p=0.018). CONCLUSIONS: In children exhibiting hearing loss in ABR testing, residual hearing at 2 kHz ASSR correlated positively with the post-CI T-level. Those with ASSRs at all frequencies had significantly lower CAP scores at the postoperative 1year. CI should not be delayed when marginal residual hearing is evident in ASSR.
Auditory Perception
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Child
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Cochlear Implantation
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Cochlear Implants
;
Ear
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Evoked Potentials, Auditory
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Evoked Potentials, Auditory, Brain Stem
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Hearing Loss
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Hearing Loss, Sensorineural
;
Hearing
;
Humans
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Retrospective Studies
;
Speech Perception
7.Hearing Threshold Prediction Using Auditory Brainstem Response and Auditory Steady-State Response in Infants and Young Children.
Korean Journal of Otolaryngology - Head and Neck Surgery 2011;54(9):592-602
Between one and three of every 1,000 neonates have sensorineural hearing loss (SNHL). It is of utmost importance to minimize the duration of auditory deprivation between the onset of bilateral deafness and intervention using hearing devices such as hearing aids and cochlear implants for achieving the best speech percpetion ability. To fit amplification accurately for children with SNHL, hearing thresholds for frequencies in the range of human communication should be evaluated. However, infants and young children are difficult to test using conventional behavioral tests, and hearing thresholds of them can be predicted using auditory brainstem response (ABR) and auditory steady-state response (ASSR). ABR is best evoked by applying a click stimulus, which allows an estimate over a broad range of high frequencies. ABR elicited by tone burst stimulus provides frequency-specific audiometric information. However, it can be difficult to record and observe at near-threshold levels, especially at lower frequencies. ABR thresholds for click and tone burst stimuli are highly correlated with behavioral thresholds, and often give an idea of the shape of an audiogram. ASSR is an auditory evoked potential, elicited with modulated tones. It provides frequency-specific hearing thresholds across the audiometric frequencies, which are well correlated with behavioral thresholds. However, the accuracy of threshold prediction decreases directly with the decrease of degree of hearing loss, and hearing thresholds cannot be predicted for auditory neuropathy. ASSR is most useful for estimating auditory thresholds for patients with no evidence of auditory neuropathy by the click ABR and OAEs, and who have an ABR only at high intensities or no ABR at a maximum stimulus level. Even if hearing thresholds are predicted through ABR and ASSR, behavioral testing including behavioral observation audiometry, visual reinforcement audiometry, or play audiometry should be employed repeatedly to verify the predicted thresholds, becasue the thresholds of ABR and ASSR are not true measure of hearing acuity but just responses generated at the brainstem.
Audiometry
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Auditory Threshold
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Brain Stem
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Child
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Cochlear Implants
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Deafness
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Evoked Potentials, Auditory
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Evoked Potentials, Auditory, Brain Stem
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Hearing
;
Hearing Aids
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Hearing Loss
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Hearing Loss, Central
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Hearing Loss, Sensorineural
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Humans
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Infant
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Infant, Newborn
;
Reinforcement (Psychology)
8.A Case of Cochlear Implantation in Neurofibromatosis Type II.
Se Joon OH ; Ji Hwan PARK ; Keun Ik YI ; Eui Kyung GOH
Korean Journal of Otolaryngology - Head and Neck Surgery 2015;58(7):509-513
Patients with neurofibromatosis type 2 (NF2) develop bilateral vestibular schwannomas that can cause binaural progressive hearing loss in most individuals. Auditory rehabilitation for bilateral profound sensorineural hearing loss in patients with NF2 poses a great therapeutic challenge. An auditory brainstem implantation may be an option after tumor excision, but its hearing results are still relatively unsatisfactory. A cochlear implantation (CI) may be another option in those cases where the cochlear nerve has been left intact after tumor excision or in those cases that have been kept stable after treating with Gamma-Knife. Here we report a case of undergoing CI after having been treated with Gamma-Knife in NF2 and showing improved open-set speech perception.
Auditory Brain Stem Implantation
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Auditory Brain Stem Implants
;
Cochlear Implantation*
;
Cochlear Implants*
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Cochlear Nerve
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Hearing
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Hearing Loss
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Hearing Loss, Sensorineural
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Humans
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Neurofibromatosis 2*
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Neuroma, Acoustic
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Radiosurgery
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Rehabilitation
;
Speech Perception
10.A rat model for cochlear implant research.
Wei LU ; Jin XU ; R K SHEPHERD
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2008;22(13):603-605
OBJECTIVE:
To introduce a rat model for use in cochlear implant related research.
METHOD:
Five deafened Hooded-Wistar rats were implanted with a scala tympani electrode array using a new surgical method. Electrically evoked brainstem responses (EABRs) using bipolar stimulation were recorded and cochlear history was assessed.
RESULT:
Electrically evoked brainstem responses with normal configuration confirmed the functional status of the cochlear implantation. There was no evidence of severe insertion-induced damage of intra-cochlear structure.
CONCLUSION
The surgical method established in the rat model is a safe and effective procedure for acute or chronic cochlear implantation.
Animals
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Cochlear Implantation
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methods
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Cochlear Implants
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Evoked Potentials, Auditory, Brain Stem
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Male
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Models, Animal
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Rats
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Rats, Wistar