Theory of mind in children with cochlear implants: Comparison with age- and sex-matched children with normal hearing.

OBJECTIVES/HYPOTHESIS: Theory of mind (ToM) is a crucial ability for maintaining normal social interaction and is directly related to language ability. This study was performed to compare ToM between children with congenital hearing loss who have received cochlear implantation (CI) and those with normal hearing (NH). STUDY DESIGN: Case-control study design. METHODS: One hundred children, aged 2-12 years, participated: 50 children who received CI before 36 months of age (CI group) and one-to-one age- and sex-matched children with normal hearing (NH group). All children underwent tests to examine receptive language ability and ToM. Receptive language was measured using the Receptive and Expressive Vocabulary Test, and ToM was measured using the Theory of Mind Task Battery (ToM-TB). The scores of the two tests were compared between the CI and NH groups. RESULTS: The ToM-TB score in the CI group correlated positively with age and receptive language score. ToM-TB scores did not differ significantly between children in the CI group who achieved normal receptive language and the NH group. However, these children in the CI group scored lower than those in the NH group on some advanced ToM tasks that require the ability to understand second-order emotion, message-desire discrepancy, or second-order false belief. CONCLUSIONS: This case-control study found that children with CI who achieve normal receptive language ability have ToM that is similar to that in children with NH. However, these children exhibited weakness in advanced ToM skills. Interventions to facilitate the development of advanced ToM are needed for children with CI.

School adjustment of adolescents with sequential bilateral cochlear implants in mainstream school.

OBJECTIVES: Little is known about the school adjustment of adolescents with sequential bilateral cochlear implants (CIs) in mainstream educational settings. This study aims to investigate the school adjustment of adolescents with sequential bilateral CIs, in comparison to those of age-matched adolescents with typical hearing (TH), to explore the relationships between individual variables and school adjustment in the bilateral CI group, and to assess the factors leading to strong school adjustment in the bilateral CI group. METHODS: Twenty-five adolescents with sequential bilateral CIs and 30 adolescents with TH, aged 13-19 years, participated in this study. The adolescents completed the school adjustment scale (SAS). RESULTS: The two groups were not significantly different on overall SAS scores. However, the TH group scored higher on the SAS than the sequential bilateral CI group with regard to communication skills and relationships with peers. In the bilateral CI group, SAS scores significantly correlated with open-set sentence and receptive vocabulary scores. Receptive vocabulary scores were a significant predictive factor for the level of school adjustment for the bilateral CI group. CONCLUSION: Adolescents who received sequential bilateral CIs adapted well to mainstream schools. However, they did experience barriers to communication and to make friends in mainstream schools, and their level of school adjustment was affected by their receptive vocabulary skills.

Trans-tympanic insertion of an angiocatheter with a stopper for treatment of patulous Eustachian tube.

BACKGROUND: Plugging of the Eustachian tube (ET) is an effective method for treating patulous Eustachian tube (PET). However, no material suitable for plugging is commercially available. A plugging material was made using an angiocatheter and a ventilating tube (VT). METHODS: An 18-gauge angiocatheter was cut 25 mm from the tip, and the cut end was occluded and widened by melting using a candle. The angiocatheter was inserted into the hole of a Paparella type 1 VT, which was moved to the cut end of the catheter. The VT acted as a stopper at tympanic orifice of ET to prevent the angiocatheter from descending into nasopharynx. Two women with PET received ET-plugging surgery using this plugging material via trans-tympanic approach. RESULTS: All symptoms of PET disappeared after surgery. There have been no postoperative complications, and the catheter has functioned well without extrusion. CONCLUSION: A plug created from an angiocatheter and a VT is easy to make and is effective for the treatment of PET.

Cortical Auditory Evoked Potential in Adults With Cochlear Implants: A Comparison With Adults With Normal Hearing.

BACKGROUND AND OBJECTIVES: To examine the maturational status of the auditory cortex in adults with cochlear implants (CIs) using the latencies of the P1, N1, and P2 components of cortical auditory-evoked potentials (CAEPs). SUBJECTS AND METHODS: A total of 25 adults with CIs and 25 age-matched, normal-hearing control subjects participated in this study. Specifically, patients with CIs were divided into three groups depending on their age of deafness onset: Group A comprised patients with prelingual deafness who had received CI during early childhood (n=7), Group B comprised patients with early childhood-onset, progressive deafness who had received CI during childhood (n=6), and Group C comprised patients with adult-onset deafness (n=12). The P1, N1, and P2 latencies of their CAEPs were then compared between CI patients and normal-hearing subjects. RESULTS: All participants showed clear CAEP responses. P1 and N1 latencies in Group A and Group C patients were significantly longer than those in the control group. Meanwhile, Group B patients had significantly longer N1 and P2 latencies, as compared with those in the control group. CONCLUSIONS: Patients with prelingual deafness and those with early-childhood onset, progressive deafness who received CI developed primary and higher-order auditory areas postoperatively when they became adults. However, their auditory cortex maturational statuses seemed to be worse than that of normal-hearing individuals. Furthermore, adult patients with late-onset deafness might experience degenerative auditory cortex changes during the auditory deprivation period between deafness onset and cochlear implantation.

P1 cortical auditory evoked potential in children with unilateral or bilateral cochlear implants; implication for the timing of second cochlear implantation.

OBJECTIVE: To examine maturation of the central auditory pathway, using P1 cortical auditory evoked potential (CAEP), in children who had received unilateral or bilateral cochlear implantation (CI). STUDY DESIGN: Prospective study. SETTING: Tertiary referral hospital. METHODS: Twenty children who had received CI due to congenital, or prelingual, deafness participated in the study. Participants had received the 1st implant at a mean age of 3.4 ± 0.7 years; 16 had also received a 2nd CI for the contralateral ear, at a mean age of 11.1 ± 2.1 years. P1 CAEP was recorded while using the 1st implant and, for those who received contralateral CI, within 2 weeks of switching on the 2nd implant. Relations between P1 latency and duration with the 1st implant, and between age at 1st CI and P1 latency, were investigated. Relations between P1 latency with the 1st and 2nd implants, and between the interstage interval and difference between P1 latencies with the 1st and 2nd implants, were also examined. RESULTS: P1 CAEP with the 1st implant was present in 16 of the 20 children. Mean P1 latency was shorter in the early CI group compared with the late CI group, but this difference was not statistically significant (p = 0.154). There was a significant negative correlation between the duration with the 1st implant and P1 latency (r = - 0.783, p < 0.001). Among the 16 children with sequential bilateral CI, P1 CAEP with the 2nd implant was present in 10. There was a significant negative correlation between the duration with the 1st implant before receiving the 2nd implant and P1 latency with the 2nd implant (r = - 0.710, p = 0.021); there was also a significant positive correlation between P1 latency with the 1st and 2nd implants (r = 0.722, p = 0.018). There was not a significant correlation between interstage interval and the difference between the two P1 latencies (r = - 0.430, p = 0.248). CONCLUSION: Longer cochlear implant use is associated with shorter P1 latency. Unilateral hearing with the 1st implant may positively affect P1 latency with the 2nd CI ear. These findings imply that increased auditory experience may influence central auditory pathway maturation and that the degree of central auditory pathway maturation before the 2nd CI, rather than the timing when the surgery is received, may influence 2nd CI outcome in children with sequential bilateral cochlear implants.

A Case of Auditory Neuropathy Caused by Pontine Hemorrhage in an Adult.

A pontine hemorrhage can evoke several neurological symptoms because the pons contains various nuclei and nerve fibers. Hearing loss can develop as a result of a pontine hemorrhage because there is an auditory conduction pathway in the cochlear nucleus of the pons. However, very few cases of hearing loss caused by pontine lesions have been reported, and there have been no reports of auditory neuropathy that developed following a pontine hemorrhage. Recently we had a patient who experienced a nontraumatic pontine hemorrhage who was diagnosed with auditory neuropathy. The 34-year-old male patient was admitted to the emergency department with sudden alteration of mental status. His brain computed tomographic imaging revealed a hemorrhage in the central pons. He complained of hearing difficulties after his mental status recovered through conservative treatment, but a pure-tone audiogram showed very mild hearing loss in both ears. Further hearing tests using otoacoustic emissions, which showed normal responses, and auditory brainstem responses, which showed no waveforms at maximum stimulus intensity, revealed that his hearing difficulties were caused by auditory neuropathy. This case implies that the threshold of sound detection can be preserved in patients with pontine hemorrhage who complain of hearing difficulties. Auditory neuropathy should be considered as a possible cause of hearing difficulties in these patients and appropriate hearing tests should be performed.

Delayed-onset hearing loss in pediatric candidates for cochlear implantation.

The objective of this study was to evaluate the clinical significance of delayed-onset hearing loss in children. Seventy-three children who underwent cochlear implantation (CI) were included. They were divided into a congenital hearing loss group (n = 50) and a delayed-onset hearing loss group (n = 23). The age at diagnosis of hearing loss, age at the beginning of auditory habilitation, the age at CI, and the postimplant speech perception abilities were compared between the two groups. Children in the congenital hearing loss group were confirmed to have hearing loss at a mean age of 0.3 years, and those in the delayed-onset hearing loss group were diagnosed with hearing loss at a mean age of 2.0 years. Auditory habilitation began at a mean age of 0.4 and 2.0 years, and CI was performed at a mean age of 1.4 and 2.6 years, respectively. Children in the congenital hearing loss group had better scores on speech perception tests than those in the delayed-onset hearing loss group, but the differences were not significant. About half of the children with delayed-onset hearing loss (57 %) had risk factors associated with delayed-onset hearing loss. A high prevalence of delayed-onset hearing loss was noted in the group of children who underwent CI. Risk factors for hearing loss were not found in 43 % of children with delayed-onset hearing loss. Universal screening for delayed-onset hearing loss needs to be performed during early childhood.

Comparative Study for Efficacy and Safety of Adenoidectomy according to the Surgical Method: A Prospective Multicenter Study.

BACKGROUND/OBJECTIVE: There have been several operative techniques for adenoidectomy and their efficacy and morbidity are different according to the technique. This prospective multicenter study was aimed to compare the efficacy and morbidity of coblation adenoidectomy (CA) with those of power-assisted adenoidectomy. STUDY DESIGN: Prospective multi-institutional study. METHODS: Children who underwent CA, power-assisted adenoidectomy with cauterization (PAA+C) or without cauterization (PAA-C) due to adenoid hypertrophy were enrolled from 13 hospitals between July 2013 and June 2014. Mean operation time, degree of intraoperative bleeding and postoperative bleeding rate were evaluated. RESULTS: A total of 388 children (mean age ± standard deviation = 6.6 ± 2.5 years; 245 males and 143 females) were included. According to the adenoidectomy technique, the children were classified into 3 groups: (1) CA (n = 116); (2) PAA+C (n = 153); and (3) PAA-C (n = 119). Significant differences were not found in age and sex among three groups. In the CA group, mean operation time was significantly shorter (P < 0.001) and degree of intraoperative bleeding was significantly less (P < 0.001) compared to PAA+C or PAA-C group. Delayed postoperative bleeding rate of PAA-C group was significantly higher than that of CA or PAA+C group (P = 0.016). CONCLUSIONS: This prospective multicenter study showed that CA was superior to PAA in terms of mean operation time and degree of intraoperative bleeding.

Criteria for Selecting an Optimal Device for the Contralateral Ear of Children with a Unilateral Cochlear Implant.

OBJECTIVE: To identify clinical criteria for selecting the aiding device for the contralateral ear of children with a unilateral cochlear implant (CI). METHODS: Sixty-five children, including 36 bilateral CI users and 29 bimodal users, participated in the study. A speech perception test (monosyllabic word test) in noise was administered. The target speech (65 dB sound pressure level) was presented from the front loudspeaker, and noise (10 dB signal-to-noise ratio) was presented from 3 directions: from in front of the child and 90° to the child's right and left sides. The test was performed using the first CI alone and under bilateral CI or bimodal conditions. The bilateral benefits to speech perception in noise were compared between bilateral CI users and bimodal users. RESULTS: Significant benefits in speech perception in noise were evident in bilateral CI users in all 3 noise conditions. In bimodal users, the hearing threshold at low frequencies of ≤1 kHz in the nonimplanted ear affected the bilateral benefit. Bimodal users with a low-frequency hearing threshold ≤90 dB hearing level (HL) showed a significant bilateral benefit in various noise conditions. By contrast, bimodal users with a low-frequency hearing threshold >90 dB HL showed no significant bilateral benefits in all 3 noise conditions. CONCLUSIONS: Bilateral CI and bimodal listening provide better speech perception in noise than unilateral CI alone in children. The contralateral CI is better than bimodal listening for children with a low-frequency hearing threshold >90 dB HL. A hearing threshold at low frequencies of ≤1 kHz may be a good criterion for deciding on the type of device for the contralateral ear of children with a unilateral CI.

A new classification of cochleovestibular malformations and implications for predicting speech perception ability after cochlear implantation.

OBJECTIVES: The aims of this study were to introduce a new classification of cochleovestibular malformation (CVM) and to investigate how well this classification can predict speech perception ability after cochlear implantation in children with CVM. METHODS: Fifty-nine children with CVM who had used a cochlear implant for more than 3 years were included. CVM was classified into 4 subtypes based on the morphology of the cochlea and the modiolus on temporal bone computed tomography (TBCT): normal cochlea and normal modiolus (type A, n = 16), malformed cochlea and partial modiolus (type B, n = 31), malformed cochlea and no modiolus (type C, n = 6), and no cochlea and no modiolus (type D, n = 6). Speech perception test scores were compared between the subtypes of CVM using analysis of covariance with post hoc Bonferroni test. Univariate and multivariate regression analyses were used to identify the significant predictors of the speech perception test scores. RESULTS: The speech perception test scores after implantation were significantly better in children with CVM type A or type B than in children with CVM type C or type D. The test scores did not differ significantly between the implanted children with CVM type A or type B and those without CVM. In univariate regression analysis, the type of CVM was a significant predictor of the speech perception test scores in implanted children with CVM. Multivariate regression analysis revealed that the age at cochlear implantation, cochlear nerve size and preimplantation speech perception test scores were significant predictors of the postimplantation speech perception test scores. The chance of cochlear nerve deficiency increased progressively from CVM type A to type D. CONCLUSION: The new classification of CVM based on the morphology of the cochlea and the modiolus is simple and easy to use, and correlated well with postimplantation speech perception ability and cochlear nerve status. This simple classification of CVM using TBCT with cochlear nerve assessment by magnetic resonance imaging is helpful in the preoperative evaluation of children with CVM.

Expression profile of fas-fas ligand in spiral ganglion cells during apoptosis.

OBJECTIVES: To examine the expression profile of Fas-Fas ligand (FasL) during glutamate (Glu)-induced spiral ganglion cell (SGC) apoptosis. METHODS: Cultured SGCs were treated with 10-mM, 25-mM, and 50-mM concentrations of Glu and incubated for 24 or 48 hours. The expression intensity of FasL, Fas, caspase 3, and morphology of single SGC were evaluated using immunofluorescence staining. RESULTS: In semiquantitative analysis of the Glu-treated SGC, FasL, and caspase 3 expression intensity were increased with concentration- and time-dependent manner. Fas expression intensity did not change with different concentration at 48 hours. In morphologic analysis of the Glu-treated SGC, number of apoptotic cells were increased with concentration- and time-dependent manner. CONCLUSION: FasL was expressed in apoptotic SGCs, suggesting that the Fas-FasL signaling pathway may be involved in the Glu-induced apoptosis of dissociated SGCs.

AAC intervention using a VOCA for deaf children with multiple disabilities who received cochlear implantation.

OBJECTIVES: The aim of this study was to examine the efficacy of a new habilitation approach, augmentative and alternative communication (AAC) intervention using a voice output communication aid (VOCA), in improving speech perception, speech production, receptive vocabulary skills, and communicative behaviors in children with cochlear implants (CIs) who had multiple disabilities. METHODS: Five children with mental retardation and/or cerebral palsy who had used CIs over two years were included in this study. Five children in the control group were matched to children who had AAC intervention on the basis of the type/severity of their additional disabilities and chronological age. They had limited oral communication skills after cochlear implantation because of their limited cognition and oromotor function. The children attended the AAC intervention with parents once a week for 6 months. We evaluated their performance using formal tests, including the monosyllabic word tests, the articulation test, and the receptive vocabulary test. We also assessed parent-child interactions. We analyzed the data using a one-group pretest and posttest design. RESULTS: The mean scores of the formal tests performed in these children improved from 26% to 48% in the phoneme scores of the monosyllabic word tests, from 17% to 35% in the articulation test, and from 11 to 18.4 in the receptive vocabulary test after AAC intervention (all p < .05). Some children in the control group showed improvement in the speech perception, speech production, and receptive vocabulary tests for 6 months, but the differences did not achieve statistical significance (all p > .05). The frequency of spontaneous communicative behaviors (i.e., vocalization, gestures, and words) and imitative words significantly increased after AAC intervention (p < .05). CONCLUSIONS: AAC intervention using a VOCA was very useful and effective on improving communicative skills in children with multiple disabilities who had very limited oral communication skills after cochlear implantation.

Auditory neuropathy spectrum disorder: predictive value of radiologic studies and electrophysiologic tests on cochlear implant outcomes and its radiologic classification.

CONCLUSION: The width of the bony cochlear nerve canal (BCNC) and the size of the cochlear nerve are reliable predictors of long-term speech perception abilities for children with auditory neuropathy spectrum disorder (ANSD) after cochlear implantation (CI). In addition, electrical stapedial reflex (ESR) and electrical compound action potential (ECAP) also have considerable value in predicting postoperative speech perception abilities in these children. OBJECTIVES: To assess whether speech perception abilities after CI in children with ANSD can be predicted from the results of radiologic studies and electrophysiologic tests. METHODS: Fifteen children with ANSD underwent CI. The width of the BCNC and the size of the cochlear nerve were measured using preoperative CT and MRI. The results of early postoperative ESR, ECAP, and implant evoked electrical auditory brainstem response were reviewed. The latest speech perception test scores were also reviewed. RESULTS: Radiologic findings of normal BCNC and normal cochlear nerve correlated with excellent speech perception abilities after CI. A narrow or obliterated BCNC and a deficient cochlear nerve correlated with poor speech perception abilities. Children with good speech perception abilities showed robust responses on ESR and ECAP, but there were no responses from any of the children with poor speech perception abilities.

Functional benefits of sequential bilateral cochlear implantation in children with long inter-stage interval between two implants.

OBJECTIVES: Older children are increasingly deriving binaural benefits from sequential bilateral cochlear implantation, and this procedure should be considered by experienced cochlear implant centers. This study aimed to identify the influence of a long inter-stage interval between two implants in older children. Speech perception and everyday listening performance were investigated and analyzed according to the length of the inter-stage interval. STUDY DESIGN AND SETTINGS: Forty-two children who received sequential bilateral cochlear implantation participated in this study. Their average ages at the first and second implantation were 4.2 and 9.7 years, respectively. All subjects acquired excellent speech performance from their first implant, and the mean inter-stage interval was 5.5 years. Speech perception in quiet was assessed by formal speech measures, and postoperative performance using the second implant only was compared with the preoperative performance. Speech perception in noise test was administered using three noise directions with noise (+10 dB signal-to-noise ratio) from front and 90° to each side, and the change in performance using the first implant only and both implants were analyzed across the three noise directions. Subjects were divided into three groups according to their inter-stage interval (group I, 3-4.9 years; group II, 5-6.9 years; and group III, 7-9.9 years), and the test results were compared between the groups. Functional hearing benefits in daily life were measured by a questionnaire before and after bilateral cochlear implantation. RESULTS: The speech perception abilities in quiet using the second implant only improved quickly and were similar to those using the first implant only within 1 year after the second implantation. The scores for the monosyllabic word test (phoneme: p=0.052; word: p=0.125) and common phrases sentence test (p=0.062) 6 month after the second implantation, and the Categories of Auditory Performance score (p=1.000) 1 year after the second implantation using the second implant only did not differ significantly from those using the first implant only. Speech perception was significantly better using both implants than using the first implant in all three noise conditions (speech and noise in front: p=0.004; speech in front and noise to the first implant: p=0.003; speech in front and noise to the second implant: p<0.001), and the effect of noise direction was negligibly small. No salient influence of inter-stage interval was observed in both quiet and noise tests. The second and third groups with longer inter-stage intervals (>5 years) achieved performance close to the level of the first group with a shorter interval. These subjects obtained significantly better functional hearing benefits in the everyday environment with bilateral implants compared with the first implant (p=0.018). CONCLUSION: The subjects in this study showed rapid postoperative progression within 6 months after the second implantation, and more listening benefits in noise and daily life with bilateral implants. This group of older children, who were good performers with the first implant, developed auditory perceptual competence in the second ear and achieved functional binaural benefits with their two implants. Sequential bilateral cochlear implantation should be recommended to this group of older children despite a long inter-stage interval between two implants.

Cortical auditory evoked potential in aging: effects of stimulus intensity and noise.

OBJECTIVE: Older adults often have more difficulty understanding speech than younger adults do, particularly in the presence of noise. Such age-related speech perception difficulties may be related to declines in central auditory processing. Additionally, it has been hypothesized that impaired auditory processing might be related to neural dysynchrony. The purpose of this study was to examine the effects of stimulus intensity and noise on the N1-P2 response in younger and older normal-hearing adults. METHODS: Eight younger and 8 older normal-hearing adults participated in this study. Brief 100-ms tones (1.0 kHz, 100-60 dB SPL) in quiet and in continuous broadband noise (70 dB SPL) were used to evoke the N1-P2 responses. The N1-P2 components were analyzed as a function of stimulus intensity in both groups. RESULTS: N1 latencies to tones in quiet for older adults were delayed only at 60 dB SPL compared with those for younger adults. Additionally, N1 latencies to tones in noise were prolonged in older adults compared with those in younger adults even at 70 dB SPL (SNR = 0). No significant age effects were observed for the P2 latencies and N1-P2 amplitudes between the groups. CONCLUSION: N1 latency to tones with lower intensity and noise were delayed in older adults compared with those in younger adults. These stimulus intensity and noise issues can affect synchronized neural activity underlying the auditory processing and may provide a partial explanation for the difficulties shown by older adults in understanding speech.

MAP optimization as a predictor of cochlear implant outcomes in children with narrow internal auditory canal.

OBJECTIVES: The purposes of this study were to investigate the auditory performance and MAP characteristics of implanted children with narrow internal auditory canal (IAC), and to examine the clinical usefulness of MAP optimization as a predictor of their cochlear implant (CI) outcomes by analyzing their auditory performance and habilitation methods in relation to MAP optimization. METHODS: Eight children with narrow IAC who had used a CI over 3 years were included. We retrospectively examined their auditory performance and MAPs. Auditory performance was measured by the Categories of Auditory Performance (CAP) and monosyllabic word tests before and after implantation. The relationship between auditory performance and MAP parameters was explored, and their habilitation methods were analyzed. RESULTS: Mean CAP scores improved from .25 preoperatively to 3.5 3 years postoperatively. Mean scores for monosyllabic word tests improved from 0% preoperatively to 27.8% 3 years postoperatively. The children used MAPs with a wider pulse width than the default setting. Four children using optimal MAPs achieved open-set speech perception, so were trained in the oral approach. The other four using suboptimal MAPs because of non-auditory stimulation achieved no open-set speech perception, so were trained in the total communication approach. CONCLUSIONS: MAP optimization had a predictable value in determining the postoperative performance of children with narrow IAC who received a CI. The most suitable habilitation method can be determined early after implantation by identifying the presence of MAP optimization.

Cochlear implantation in children with cochlear aplasia.

CONCLUSION: Children with cochlear aplasia can achieve favorable speech perception abilities from cochlear implantation (CI) by inserting an electrode array into the vestibule if an audiological response is reliably demonstrated before surgery by behavioral audiometry and objective measures. OBJECTIVES: The purpose of this study was to evaluate the surgical outcome of CI in children with cochlear aplasia. METHODS: The medical records of 454 children who underwent CI at the Dong-A University Hospital between January 1994 and September 2011 were reviewed. The prevalence of cochlear aplasia and the preoperative evaluations, operative findings, and postoperative speech perception abilities of implanted children with cochlear aplasia were evaluated. RESULTS: The implanted children with cochlear aplasia accounted for 2% of those with inner ear malformations and 0.4% of all pediatric cochlear implantees. They showed audiological responses in preoperative electrophysiologic tests, and the eighth nerve was present in magnetic resonance imaging. The electrode array was inserted into the vestibule through an oval window after removing the stapes or through a transmastoid labyrinthotomy site. Electrical compound action potential and electrical auditory brainstem response tests showed clear neural responses after implantation. The hearing thresholds of the implanted ear improved to 25 dB HL and the children achieved significant open set speech perception abilities.

Changes in the hearing thresholds of infants who failed the newborn hearing screening test and in infants treated in the neonatal intensive care unit.

OBJECTIVES: The aim of this study was to investigate changes in the hearing thresholds during the first year of life in infants who failed the newborn hearing screening (NHS) test and of infants treated in the neonatal intensive care unit (NICU). METHODS: From March 2007 to November 2010, 193 healthy infants who failed the NHS test and 51 infants who were treated in the NICU were referred for evaluation of hearing acuity. Their hearing was evaluated using impedance audiometry, auditory brainstem response (ABR), and otoacoustic emission before 6 months of age, and follow-up hearing tests were administered before 12 months of age. Changes in their hearing thresholds were then analyzed. RESULTS: Of the 193 healthy infants who failed the NHS test, 60 infants (31%) had normal hearing acuity, 126 infants (65%) had sensorineural hearing loss (SNHL, ABR threshold ≥40 dB) and 7 infants (4%) had auditory neuropathy (AN). On the follow-up hearing tests, which were conducted in 65 infants, 6 infants showed a hearing threshold deterioration of more than 20 dB, and 19 infants showed a hearing threshold improvement of more than 20 dB. Of the 51 infants who were treated in the NICU, 38 infants (75%) had normal hearing acuity, 12 infants (24%) had SNHL, and one infant (2%) had AN. In the follow-up hearing tests, which were performed in 13 infants, one infant with normal hearing progressed to severe hearing loss. Five infants who had SNHL showed a hearing threshold improvement of more than 20 dB, and 4 infants recovered to normal hearing. CONCLUSION: The hearing thresholds of infants with congenital SNHL can change during the first year of life; therefore, the importance of administration of follow-up hearing tests is emphasized. Irreversible intervention such as cochlear implantation should be considered with great caution within the first year after birth.

Recovery function of electrically evoked compound action potential in implanted children with auditory neuropathy: preliminary results.

CONCLUSION: The results of this study show that the temporal processing ability in children with auditory neuropathy (AN) can be restored to some degree by electrical stimulation through a cochlear implant. In addition, the electrically evoked compound action potential (ECAP) may be a useful index to predict outcomes in implanted children with AN. OBJECTIVES: The purpose of this study was to evaluate restoration of the temporal processing abilities in implanted children with AN using ECAP recovery function and speech perception. METHODS: Ten children who had received cochlear implantations participated in this study, including six with AN and four with sensorineural hearing loss (SNHL). ECAP recovery functions were measured, and the slopes of ECAP recovery functions in implanted children with AN were compared with those of implanted children with SNHL. Open-set speech perception test scores of implanted children with AN were compared with those of 78 implanted children with SNHL. RESULTS: The slopes of the ECAP recovery function in children with AN did not differ significantly from those in children with SNHL. The group of children with robust ECAPs showed good postoperative performance. However, the group with no ECAPs showed poor performance.

Performance of children with mental retardation after cochlear implantation: speech perception, speech intelligibility, and language development.

CONCLUSION: Children with mental retardation (MR) obtain demonstrable benefit from cochlear implantation, and their postoperative performance was tempered by the degree of MR. OBJECTIVE: The purpose of this study was to investigate the performance of children with MR after implantation, and to explore their progress according to the degree of MR. METHODS: Fifteen implanted children with MR were included. Progress in speech perception, speech intelligibility, and language was measured using Categories of Auditory Performance, monosyllabic word test, Speech Intelligibility Rating, and Language Scale before and after implantation. We retrospectively examined outcomes and explored the association between the progress and the degree of MR after implantation. We compared monosyllabic word test scores using repeated-measures ANOVA. RESULTS: Speech perception and speech intelligibility for children with mild MR improved consistently after implantation. After implantation, monosyllabic word test scores did not differ significantly between children with mild MR and children with no additional disabilities. Although language development of children with mild MR was slow, they could communicate verbally 3 years after implantation. Children with moderate MR progressed more slowly and had limitations in speech and language development, and these children could communicate by vocalization and gesture 3 years after implantation.