Evaluation of the non-auditory responses in individuals with auditory brainstem implant.

OBJECTIVES: After auditory brainstem implant (ABI) surgery, stimulation of certain cranial nerves may result in a non-auditory response, and the electrodes that stimulate these nerves may be deactivated. The goals of this study are to compare the number of active electrodes in the initial activation and the last fitting, to investigate non-auditory response types and their frequency as a result of non-auditory stimulation, to compare the placements of deactivated electrodes as a result of non-auditory stimulation in the initial activation and the last fitting. METHODS: The computer software system was used to perform a retrospective analysis of the fitting data of 69 ABI users who underwent auditory brainstem implant surgery between January 1997 and January 2019. The non-auditory response types, deactive electrodes, and the positioning of the deactive electrodes horizontally and vertically were recorded in these users during the initial activation and the last fitting. RESULTS: There was no statistically significant difference between the number of active electrodes in the initial activation and the last fitting. The proportion of the users with deactive electrodes in the initial activation and the last fitting was not statistically significant different. In the horizontal and vertical placement classification, the placement of the deactive electrodes was not statistically different between initial activation and last fitting. The most common type of non-auditory response was facial nerve stimulation at the initial activation and no auditory perception at the last fitting. According to the difference between the number of active and deactive electrodes in the initial activation and the last fitting, as well as the auditory and non-auditory responses, it was found that the ABI users were statistically different between the initial activation and the last fitting. CONCLUSION: The results of this study show that not only auditory but also non-auditory responses occur in most ABI users. In addition, to the best of our knowledge, this study is the first to examine the frequencies of non-auditory response types, and the placement of the electrodes that cause these responses according to horizontal and vertical classifications.

Pediatric cochlear implant fitting parameters in inner ear malformation: Is it same with normal cochlea?

OBJECTIVES: The aim was to evaluate the cochlear implant (CI) mapping parameters of CI users with inner ear malformation (IEM) and to reveal the changes in parameters over time. METHODS: In total, 118 CI users were included with 127 ears (68-IEM; 59-normal cochlear anatomy) in present retrospective study. The impedance measurements, thresholds levels-THR, most comfortable levels- MCL, pulse width-PW and rate values were analyzed in both IEM and control group at the initial activation, 6th,12th and 24th months postoperatively. RESULTS: There were statistically significant differences in impedance measurements in several time points. And also, there was a remarkable difference in THR & MCL and PW values between IEM and control groups in all time points (p < 0.05). THR & MCL levels and PW values increased significantly between all time periods in both groups (p < 0,008) and values of parameters in IEM-group were higher than those of control group. When comparing rates, statistically significant difference was observed only at the initial activation in both within (p < 0.001) and between groups (p = 0.03). CONCLUSION: Pediatric CI users with IEM need individual changes in fitting parameters. More frequent map sessions should be planned as they require more PW, THR and MCL increase over time. The increase rate differs between IEM subgroups depending on the deviation of malformation from the normal cochlear anatomy. This study is the first to in its attempt to reveal the mapping characteristics and long-term changes in pediatric CI users with different IEM subgroups.

Revision Surgery for Pediatric Nontumor Auditory Brainstem Implant Users: Audiological, Rehabilitative, and Surgical Outcomes.

OBJECTIVE: To report the audiological, rehabilitative, and surgical outcomes of revision surgery for pediatric auditory brainstem implant (ABI) users. STUDY DESIGN: Retrospective cohort. SETTING: Tertiary referral center. PATIENTS: Five pediatric ABI users who had revision surgery for device malfunctions. INTERVENTIONS: Revision surgery for ABI malfunctions. MAIN OUTCOME MEASURES: The findings of free-field audiometry with the device, the Meaningful Auditory Integration Scale, and the pattern discrimination, word identification, sentence recognition, and expressive and receptive language tests before the device failure and after revision surgery were obtained from the patient records and compared. RESULTS: The revision rate for pediatric ABI was 6.45%. The Meaningful Auditory Integration Scale and expressive-receptive language scores showed improvements following revision surgery, while the aided thresholds, pattern perception, and word identification scores did not change. Individual differences in performance for these measures were observed. CONCLUSION: Equal or improved performance after the revision surgeries in the current study showed that revision surgery is successful and important for pediatric ABI users. It is essential to consider remedying the loss of auditory input in sensitive periods of pediatric development.

Effects of cognitive tasks on eye movements.

Eye movements are guided by vestibular and visual information. The vestibulo-ocular knowledge of the vestibule includes eye movements in the opposite direction of head movements. This study investigated the effect of auditory "what" and "where" tasks on the visual "where" to evaluate the effects of cognitive tasks on eye movements. All subjects underwent testing with videonystagmography (VNG). The VNG battery of saccade and tracking oculomotor tests were performed. The study design was planned in three stages: (1) without any cognitive tasks, eye movements were recorded with VNG, (2) participants were asked to tell "what" sound they heard during VNG recording, and (3) the subject was asked to tell from what direction, or "where," the sound had come from during VNG recording. Providing individuals with a cognitive task changed the test results negatively in all parameters. Giving cognitive tasks to individuals spoils all VNG parameters. The VNG oculomotor tests are affected by the dual tasks. Daily tasks such as sound object localization and recognition have a significant effect on scanning the visual environment in daily life such as during driving or walking in a crowded environment.

Stapedotomy in Congenital Fixation with Cochlear Hypoplasia: A New Concept Among the Treatment Options for Cochlear Hypoplasia.

OBJECTIVES: To introduce the concept of stapedotomy as a new treatment alternative in cochlear hypoplasia (CH) and propose a new guideline for its management. METHODS: Forty-two primary cases out of 355 presented with congenital stapes fixation between January 2003 and September 2015 were included in the study. Computed tomography scans of all cases with congenital stapes fixation were reviewed, and cases with inner ear anomalies were taken into account. Eleven cases had various inner ear anomalies, and 9 cases had various types of CH. In the present paper, only the CH cases with stapes fixation, all of whom underwent stapedotomy, are reviewed regarding preoperative audiological and radiological characteristics as well as surgical findings and postoperative audiological results. RESULTS: The patients were aged between 4 and 22. There were 2 males (3 ears) and 4 females (6 ears). Three cases had bilateral stapedotomy. The remaining 3 cases had unilateral surgery. The average preoperative air-bone gap (ABG) was 50.3 dB. Postoperative hearing: preoperative ABG was 50.3 dB. Postoperative ABG was calculated as 20.1 dB hearing. CONCLUSION: Hearing loss (HL) in hypoplastic cochlea demonstrates the full spectrum of HL types. CH is a unique inner ear anomaly that can be treated with all of the available rehabilitation modalities. As a result of current findings, a new treatment algorithm for CH is proposed.

Auditory Brainstem Response Measurements in Newborns: Which Electrode Placement Is Better?

OBJECTIVE: The objective of this study was to determine the fastest and the most effective auditory brainstem response (ABR) measurement protocol for audiological diagnosis in babies up to three months of age. METHODS: Twenty-two newborns (aged 0 to 63 days) who passed the newborn screening test in at least one ear were evaluated in the study. The ABR were recorded with click stimulus using two different electrode montages (1st montage: ipsilateral mastoid, contralateral mastoid, vertex. 2nd montage: nape of the neck, vertex, cheek). Latencies of waves I, III, V and duration of the test were recorded and analyzed. RESULTS: Wave V latencies from both electrode montages were statistically shortest at the level of 70 dBnHL and longest at the level of 20 dBnHL (p=0.00). When the duration of the test at three different intensity levels were compared between the two electrode montages, only the test durations at 50 dBnHL were significantly different (p=0.017). The test times at 70 dBnHL in the first montage were observed to be significantly different in babies aged 1 to 30 days and aged 31 to 63 days (p=0.005). CONCLUSION: In protocols to evaluate the hearing of pediatric groups, it is very important to complete the ABR, which has significant value in early diagnosis, in a short time and reliably. It is concluded that in terms of practicality, the second montage is more advantageous and comfortable for both audiologists and newborns in single channel ABR systems.

Successful Use of a Cochlear Implant in a Patient with Bony Cochlear Nerve Canal Atresia.

The anatomical cause of congenital sensorineural hearing loss can be atresia of the bony cochlear nerve canal (BCNC). It has been reported that the cochlear nerve (CN) can be either hypoplastic or aplastic when the BCNC width is <1.5 mm radioanatomically. It is difficult to estimate the auditory-verbal abilities after cochlear implantation (CI) in patients with a hypoplastic CN. In such cases, it is also challenging to decide on the best treatment modality: CI or auditory brainstem implantation. In this case report, we present a 4-year-old male patient with BCNC atresia and the successful use of a cochlear implant; we also discussed the importance of audiological evaluation. A detailed radiological evaluation must be performed in every case following electrophysiological studies prior to CI. To accurately diagnose the pathology and select the surgical side, both computed tomography and magnetic resonance imaging scans should be used as complementary imaging methods in all CI candidates.

Varying effect of noise on sound onset and acoustic change evoked auditory cortical N1 responses evoked by a vowel-vowel stimulus.

INTRODUCTION: According to previous studies noise causes prolonged latencies and decreased amplitudes in acoustic change evoked cortical responses. Particularly for a consonant-vowel stimulus, speech shaped noise leads to more pronounced changes on onset evoked response than acoustic change evoked response. Reasoning that this may be related to the spectral characteristics of the stimuli and the noise, in the current study a vowel-vowel stimulus (/ui/) was presented in white noise during cortical response recordings. The hypothesis is that the effect of noise will be higher on acoustic change N1 compared to onset N1 due to the masking effects on formant transitions. METHODS: Onset and acoustic change evoked auditory cortical N1-P2 responses were obtained from 21 young adults with normal hearing while presenting 1000 ms /ui/ stimuli in quiet and in white noise at +10 dB and 0 dB signal-to-noise ratio (SNR). RESULTS: In the quiet and +10 dB SNR conditions, the N1-P2 responses to both onset and change were present. In the +10 dB SNR condition acoustic change N1-P2 peak-to-peak amplitudes were reduced and N1 latencies were prolonged compared to the quiet condition. Whereas there was not a significant change in onset N1 latencies and N1-P2 peak-to-peak amplitudes in the +10 dB SNR condition. In the 0 dB SNR condition change responses were not observed but onset N1-P2 peak-to-peak amplitudes were significantly lower, and onset N1 latencies were significantly higher compared to the quiet and the 10 dB SNR conditions. Onset and change responses were also compared with each other in each condition. N1 latencies and N1-P2 peak to peak amplitudes of onset and acoustic change were not significantly different in the quiet condition. Whereas at 10 dB SNR, acoustic change N1 latencies were higher and N1-P2 amplitudes were lower than onset latencies and amplitudes. To summarize, presentation of white noise at 10 dB SNR resulted in the reduction of acoustic change evoked N1-P2 peak-to-peak amplitudes and the prolongation of N1 latencies compared to quiet. Same effect on onsets were only observed at 0 dB SNR, where acoustic change N1 was not observed. In the quiet condition, latencies and amplitudes of onsets and changes were not different. Whereas at 10 dB SNR, acoustic change N1 latencies were higher, amplitudes were lower than onset N1. DISCUSSION/CONCLUSIONS: The effect of noise was found to be higher on acoustic change evoked N1 response compared to onset N1. This may be related to the spectral characteristics of the utilized noise and the stimuli, possible differences in acoustic features of sound onsets and acoustic changes, or to the possible differences in the mechanisms for detecting acoustic changes and sound onsets. In order to investigate the possible reasons for more pronounced effect of noise on acoustic changes, future work with different vowel-vowel transitions in different noise types is suggested.

Simultaneous Cochlear and Auditory Brainstem Implantation in Children With Severe Inner Ear Malformations: Initial Surgical and Audiological Results.

OBJECTIVE: To report the initial surgical and audiological outcomes of three pediatric patients with severe inner ear malformations who were simultaneously implanted with cochlear and brainstem implants in the same surgical session. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Three pediatric patients with severe inner ear malformations between ages of 1.9 to 2.5 years, who were simultaneously implanted with cochlear implant in one ear and auditory brainstem implant in the other ear. INTERVENTION(S): Simultaneous application of cochlar implant in one ear, auditory brainstem implant in the other ear. MAIN OUTCOME MEASURES: Free field thresholds with cochlear and brainstem implants. Surgical issues are also discussed. RESULTS: The study is descriptive in nature. Free field thresholds with each device alone and together showed good progress. One of the patients had slower progress possibly due to comorbid CHARGE syndrome. CONCLUSIONS: The results showed good progress in terms of audition with both devices. Simultaneous cochlear and brainstem application serves as a remedy for pediatric patients who are candidates for cochlear implant on one side and brainstem implant on the other side. With this simultaneous application precious time for auditory development is not lost.

Bimodal stimulation in children with inner ear malformation: One side cochlear implant and contralateral auditory brainstem implant.

OBJECTIVE: To determine audiological outcomes of children who use a cochlear implant (CI) in one ear and an auditory brainstem implant (ABI) in the contralateral ear. DESIGN: Retrospective case review. SETTING: Tertiary referral hospital. PARTICIPANTS: Twelve children followed with CI and contralateral auditory brainstem implant (ABI) by Hacettepe University Department of Otorhinolaryngology and Audiology in Turkey. All children were diagnosed with different inner ear malformations with cochlear nerve aplasia/hypoplasia. CI was planned in the ear with better sound detection during behavioural testing with inserted ear phones and with better CN as seen on MRI. Due to the limited auditory and speech progress with the cochlear implant, ABI was performed on the contralateral ear in all subjects. MAIN OUTCOME MEASURES: Audiological performance and auditory perception skills of children with cochlear nerve deficiency (CND) who use bimodal electrical stimulation with CI and contralateral ABI. RESULTS: Mean age of the subjects was 84.00 ± 33.94 months. Age at CI surgery and ABI surgery was 25.00 ± 10.98 months and 41.50 ± 16.14 months, respectively. However, hearing thresholds only with CI and only with ABI did not reveal significant difference, and auditory perception scores improved with bimodal stimulation. The MAIS scores were significantly improved from unilateral CI to bimodal stimulation (P = .002). Pattern perception and word recognition scores were significantly higher with the bimodal condition when compared to CI only and ABI only conditions. CONCLUSION: Children with CND showed better performance with CI and contralateral ABI combined. Depending on the audiological and radiological results, bimodal stimulation should be advised for children with CND.

Is Early Cochlear Implant Device Activation Safe for All on-the-Ear and off-the-Ear Sound Processors?

BACKGROUND: Cochlear implantation (CI) is an effective treatment option for patients with severe-to-profound hearing loss. When CI first started, it was recommended to wait until at least 4 weeks after the CI surgery for the initial activation because of possible complications. Advances in the surgical techniques and experiences in fitting have made initial activation possible within 24 h. OBJECTIVES: To compare the complaints and complications after early activation between behind-the-ear (BTE) and off-the-ear (OTE) sound processors and to show the impact of early activation on the electrode impedance values. METHOD: CI surgeries performed between March 2013 and July 2018 were retrospectively analyzed from the database. In total, 294 CI users were included in the present study. The impedance measurements were analyzed postoperatively at the initial activation prior to the stimulation, and 4 weeks after the initial activation in the first-month follow-up visit. A customized questionnaire was administered in the first-month follow-up fitting session to caregivers and/or patients who were using CI at least for 6 months. Medical records were also reviewed to identify any postoperative complications. RESULTS: In the early activation group, impedance values were significantly lower than in the control group (p < 0.05) at first fitting. At the first-month follow-up, no significant difference was found between the groups (p > 0.05). The most common side effects were reported to be edema (6.1%) and pain (5.7%) in the early activation group. In patients with OTE sound processors, the rate of side effects such as skin infection, wound swelling, skin hyperemia, and pain was higher than in patients with BTE sound processors; however, a statistical significance was only observed in wound swelling (p = 0.005). Selecting the appropriate magnet was defined as a problem for the OTE sound processors during the initial activation. CONCLUSION: This study revealed that early activation of CI was clinically safe and feasible in patients with BTE sound processors. When using OTE sound processors, the audiologists should be careful during the activation period and inform patients of possible side effects. The first fitting should be delayed for 4 weeks after CI for OTE sound processors. This current study is the first to report this finding with 5 years of experience in a large cohort.

Cochlear Nerve Hypoplasia: Audiological Characteristics in Children and Adults.

BACKGROUND: Cochlear nerve deficiency is a general term used to describe both cochlear nerve hypoplasia (CNH) and cochlear nerve aplasia. Although these two conditions can have similar results on audiological evaluation, CNH yields more variation in audiological tests. OBJECTIVES: To describe the audiological characteristics of the CNH cases in our series in relation to radiological findings. METHODS: We reviewed the medical charts, audiological findings, and radiological findings on cases with CNH. We included cases with CNH in one ear or both ears. Out of 90 subjects with CNH, we included a total of 40 individuals (21 women and 19 men; 49 ears) in the current study. We reviewed and analyzed the participants' audiological test results according to the radiological findings. RESULTS: Cases with CNH showed variations according to the cochlear structure. There were 13 normal cochleae, 4 with incomplete partition type I, and 32 with cochlear hypoplasia. The accompanying cochlear apertures also showed variation: 17 were normal, 28 stenotic, and 4 aplastic cochlear apertures. The subjects displayed hearing loss ranging from moderate to profound; furthermore, 4 subjects had no response to sound whatsoever. The degree of hearing loss was not statistically significantly different with regard to the presence or absence of cochlear malformation with CNH (p > 0.005). We observed both sensorineural hearing loss and mixed-type hearing loss among the CNH cases. CONCLUSIONS: CNH is the presence of a cochlear nerve that is smaller in diameter than the facial nerve. It can be accompanied with other associated inner ear malformations of different degrees of severity. We observed degrees of hearing loss ranging from moderate to profound.

Effect of Consonant Duration on Formation of Consonant-Vowel Syllable Evoked Auditory Cortical Potentials.

OBJECTIVE: To compare P1-N1-P2-N2 response latencies and amplitudes evoked by voiced and unvoiced consonant-vowel syllables (CVS) /bi/-/pi/ and /di/-/ti/ by analyzing how the cortical responses to consonants and vowels interact during the formation of a syllable-evoked response. MATERIALS AND METHODS: Auditory late latency responses were recorded from 12 healthy individuals between the ages of 20 and 40 years with normal hearing while presenting /bi/-/pi/ and /di/-/ti/ tokens and individual consonant-vowel parts of syllables. Amplitude/latency values of P1-N1-P2-N2 responses were compared between /bi/-/pi/ and /di/-/ti/ pairs. Formation of CVS-evoked responses by consonant and vowel responses was also investigated. RESULTS: N1-P2-N2 latencies evoked by /bi/ were significantly shorter than /pi/. P2-N2 amplitudes evoked by /di/ were significantly higher and N2 latencies were shorter than /ti/. N1-P2-N2 peaks of /bi/, /pi/, and /di/ seemed to be combinations of respective peaks of consonant and vowel-evoked responses. For /ti/, P1 and N1 seem to be stemming only from the consonant part, P2 from consonant P2 and vowel N1, and N2 from consonant N2 and vowel P2-N2. CONCLUSION: For both CVS pairs, longer consonant durations resulted in lower amplitudes and/or longer latencies, and this sheds light on why voiced-unvoiced CVSs evoke cortical responses with different features. Obtaining evoked responses to each consonant-vowel part of the syllables among listeners with perceptual difficulties and hearing devices might help to reveal which acoustic cues are not well represented in the auditory brain.

The role of eABR with intracochlear test electrode in decision making between cochlear and brainstem implants: preliminary results.

The objective of the study was to discuss the findings of intraoperative electrically evoked auditory brainstem response (eABR) test results with a recently designed intracochlear test electrode (ITE) in terms of their relation to decisions of cochlear or auditory brainstem implantation. This clinical study was conducted in Hacettepe University, Department of Otolaryngology, Head and Neck Surgery and Department of Audiology. Subjects were selected from inner ear malformation (IEM) database. Eleven subjects with profound sensorineural hearing loss were included in the current study with age range from 1 year 3 months to 4 years 3 months for children with prelingual hearing loss. There was only one 42-year-old post-lingual subject. eABR was recorded with an ITE and intraoperatively with an original cochlear implant (CI) electrode in 11 cases with different IEMs. Findings of eABR with ITE and their relation to the decision for CI or auditory brainstem implant (ABI) are discussed. Positive eABR test results were found to be dependent on close to normal cochlear structures and auditory nerve. The probability of positive result decreases with increasing degree of malformation severity. The prediction value of eABR via ITE on decision for hearing restoration was found to be questionable in this study. The results of eABR with ITE have predictive value on what we will get with the actual CI electrode. ITE appears to stimulate the cochlea like an actual CI. If the eABR is positive, the results are reliable. However, if eABR is negative, the results should be evaluated with preoperative audiological testing and MRI findings.

Comparison of Regularity Detection between Individuals with and without Speech-in-Noise Problems using Electrophysiological Methods.

OBJECTIVE: To analyze the cortical representations of auditory regularities and the relation between these representations and speech-in-noise (SIN) abilities and to compare two groups of participants with different SIN abilities on these cortical measures. MATERIALS AND METHODS: In total, 22 participants aged 20-40 years with normal hearing and without noise exposure, brain stem level-processing issues, neurological/psychiatric issues, or related medication were presented with three different stimuli resembling auditory regularities appearing after random sounds as well as a random series of sounds. Participants received a total of 480 stimuli in passive and active phases each (in which they actively detected regularities). Evoked responses were recorded via 20-channel standard electroencephalography (EEG) cap. RESULTS: The groups were not significantly different in terms of evoked potential parameters. A significant negative correlation was observed between amplitudes of responses evoked by decreasing the frequency regularity in the active phase and SIN scores. Response parameters were significantly different between the stimuli. Active phase latencies were shorter and amplitudes were higher than passive phase ones, except for two stimuli. CONCLUSION: Cortical representations of decreasing frequency regularity are promising for revealing the link between SIN and representations of regularity detection. This paradigm is suggested to applicable to individuals with clinical-level SIN problems [hearing aid (HA) and cochlear implant (CI) users, normal-hearing individuals, children with learning problems, children with dyslexia, and others] to reveal which process of SIN mechanism is defective; this is a complicated process with many sub-mechanisms. These results may be utilized in designing CI and HA algorithms (for more robust representations of auditory regularities) and rehabilitation programs.

Comparison of various bone cement ossiculoplasty techniques and functional results.

OBJECTIVE: In this study, functional results of different bone cement ossiculoplasty techniques are compared. METHODS: Retrospective case review at a tertiary referral center. Patients who underwent middle ear surgery and bone cement ossiculoplasty between 2006-2012 were included. A total of 52 patients, including 30 patients with 'Incus to stapes' (Group 1) and 13 patients with 'malleus to stapes' (Group 2), five patients with 'incudoplasty + stapedotomy' (Group 3), and four patients with 'malleus to incus' (Group 4) ossiculoplasty were enrolled in the study. Pre-operative and post-operative audiological findings of each group were evaluated. RESULTS: The mean hearing gain (the difference between pre-operative and post-operative air bone gap (ABG)) was 13 dB for Group 1, 30 dB for Group 2, 24 dB for Group 3, and 9 dB for Group 4. The pre-operative air pure tone averages (PTA) of groups 1, 2, and 3 improved significantly in the post-operative period (p < 0.05). Closure of post-operative ABG of patients to less than 20 dB and 10 dB were as follows: ∼70% and 43% in group 1; 86% and 76% in group 2; 100% and 60% in group 3; and 75% and 50% in group 4, respectively. CONCLUSIONS: The results showed that glass ionomer cement is a simple and effective method for reconstruction of ossicular discontinuity in various ossicular chain pathologies and can be an alternative to conventional rebridging techniques such as sculpted incus interposition or partial ossicular replacement prosthesis (PORP).