Status of the Newborn Hearing Screening in the 4-Months Age National Infant Health Checkup in Korea: A Nationwide PopulationBased Study

Background@#The aims of this study are to review data on 4-months age National Health Screening Program for Infants and Children (NHSPIC) using a National Health Insurance Service (NHIS) database, and to analyze the newborn hearing screening (NHS) results and related characteristics of the 4-months NHSPIC for 7 years in South Korea. @*Methods@#We analyzed a NHIS database of infants who had participated in the 4-month age NHSPIC from 2010 to 2016. According to the results of hearing questionnaires and physical examination, we analyzed the outcomes of NHS and related infantile and socioeconomic factors. @*Results@#Among 3,128,924 of total eligible infants in Korea between the year 2010 and 2016, 69.2% (2,164,621 infants) conducted 4-months age NHSPIC, and 94.4% (2,042,577 infants) of which performed hearing questionnaires regarding NHS. Among the total hearing examinees, premature infants accounted for 3.6%, infants who were hospitalized in the neonatal intensive care unit (NICU) for more than 5 days accounted for 5.6%, and infants with head and neck abnormalities were 0.6%. The NHS performing rate was 79.1% for total hearing examinees in 2010, but gradually increased to 88.9% in 2016. The NHS performing rate in 2016 was 93.4% for premature infants, 91.7% for NICU hospitalized babies. The mean referral rate was 0.6% for total hearing examinees, 1.4% for premature infants, and 2.3% for NICU hospitalized babies. When we analyzed the NHS performing rate and the referral rate according to the household income level, the NHS performing rate of infants in Medical Aid programs was the lowest as 65.6%, and the NHS performing rates in other five levels of NHIS was higher ranging between 85.1% to 86.0%. The referral rate of infants in the Medical Aid program (3.8%) was significantly higher than those of infants in other classes (1.10–1.25%). @*Conclusion@#The estimated overall NHS performing rate in Korea gradually increased and was 88.9% in 2016. The overall referral rate was low as 0.6%, and it was significantly different depending on the infant’s health condition and household income levels. We assume that our finding would help to establish policies managing hearing impaired children, and to develop the customized hearing care service programs considering the household economic levels.

Diagnostic Validity of Auditory Brainstem Response for the Initial Screening of Vestibular Schwannoma

Background and Objectives@#To investigate the diagnostic validity of auditory brainstem response (ABR) in the screening of vestibular schwannoma (VS). @*Subjects and Methods@#Forty patients diagnosed with VS using magnetic resonance imaging who had undergone ABR before treatment between 2005 and 2015 were included. ABR results were considered positive when findings met at least one of the following criteria: 1) absent evoked response, 2) desynchronization of waves other than wave I, 3) interpeak latency (IPL) between waves I and III >2.5 ms, 4) IPL between waves I and V >4.4 ms, 5) wave V interaural latency difference >0.2 ms, and 6) interaural difference in IPL between waves I and V >0.2 ms. @*Results@#The overall sensitivity of ABR was 85.0%. For tumors measuring 10 mm. The sensitivity of tumors confined to the internal acoustic canal was 73.3% compared with 100.0% for tumors confined to the cerebellopontine angle. In patients with serviceable hearing, the mean tumor size was 7.8±2.9 mm in patients with a normal ABR and 15.1±9.4 mm in patients with an abnormal ABR, indicating a significant difference (p10 mm in patients with serviceable hearing, supporting the need for further active diagnostic and treatment modalities in clinical practice.

Short-Term Experience in Cochlear Implantation with Slim Modiolar Electrode Array (CI532): Comparison to Previous Devices / 대한이비인후과학회지

Background and Objectives@#There have been no reports in Korea regarding cochlear implant surgeries using Cochlear Nucleus Profile Slim Modiolar electrode [CI532 (Cochlear Ltd.)], as it has been recently released in Korea. We aimed to investigate the short-term results of CI532 and compare them with previous devices with perimodiolar or straight electrodes arrays from the same manufacturer.Subjects and Method From August 2018 to July 2019, 52 patients (26 adults; 26 children) who underwent cochlear implantation of CI532 were included. The intraoperative impedance and evoked compound action potential (ECAP) threshold in each electrode were analyzed and compared with the devices with a perimodiolar electrode array [Contour Advance® (Cochlear Ltd.)] and a lateral wall electrode array [CI422 and CI522 (Cochlear Ltd.)]. Postoperative changes of hearing thresholds at each frequency (250, 500, and 1000 Hz) and aided word recognition scores (WRS) were also compared. @*Results@#CI532 showed significantly lower intraoperative impedance in the basal regions compared to the lateral wall electrode array. The ECAP thresholds of CI532 in the apical electrodes were significantly lower than that in the other two groups. After implantation, CI532 showed a significant preservation of hearing thresholds at most frequencies and showed significantly higher preservation rates than the other electrodes. However, there was no difference between the three groups regarding the postoperative short-term aided WRS. @*Conclusion@#CI532 showed lower intraoperative impedances and ECAP thresholds, and better short-term hearing preservation outcomes compared to the other electrodes, suggesting that CI532 electrode might be a better option with less traumatic insertion. However, there was no significant difference in the aided WRS, and further studies with a longer follow-up are necessary to examine the difference of audiologic outcomes.

Standardization for a Korean Version of the Speech, Spatial and Qualities of Hearing Scale: Study of Validity and Reliability / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The Speech, Spatial and Qualities of Hearing Scale (SSQ) was designed to measure self-reported auditory disability in a wide variety of listening situations. Its 49 items cover many aspects of speech perception, spatial hearing, and qualities of hearing, which constitute the three parts of SSQ. However, there has been no reliable and valid Korean version of SSQ (K-SSQ), which made the measurement of auditory disability difficult. The aim of this study is to develop a K-SSQ and to determine its reliability and validity for clinical or academic use. SUBJECTS AND METHOD: An expert panel translated the original SSQ into Korean. A bilingual translator back-translated the translated version into English, which was then compared with the original version. After cognitive debriefing, K-SSQ was administered to 400 patients with hearing disability in 14 referral hospitals. Reliability was assessed using Cronbach's alpha coefficient and correlation study. Validity was evaluated by factor analysis and criterion validity based on the results of pure tone audiometry. RESULTS: K-SSQ showed good reliability with high internal consistency (Cronbach's α=0.99), and strong positive correlations across all three parts of SSQ. Construct validity was confirmed by the results of factor analysis and criterion validity demonstrated positive correlations between each part of SSQ and the results of pure tone audiometry. CONCLUSION: The K-SSQ is a reliable and valid tool for use as a behavioral measure of hearing ability in Korean-speaking patients, and it will provide a very useful evaluation tool for both clinicians and researchers.

Translation and Standardization for a Korean Version of the Client Oriented Scale of Improvement / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Client Oriented Scale of Improvement (COSI) has been designed to identify client needs, changes in listening ability, and final listening ability in situations important to each client. The aim of this study was to translate COSI into Korean with subsequent linguistic validation and to determine the reliability of the Korean version of the COSI (K-COSI). SUBJECTS AND METHOD: An expert panel translated the original version of COSI into the Korean language. A bilingual translator back-translated the translated version into English, which was subsequently compared with the original English version. K-COSI was administered at 14 referral hospitals, to 128 patients with hearing disability after cognitive debriefing. Reliability was assessed using correlation study. RESULTS: K-COSI showed an excellent test-retest correlation and high reliability in degree of change (Spearman correlation=0.89, interclass correlation coefficient=0.922). It also showed a fair test-retest correlation and high reliability in final hearing ability (Spearman correlation=0.49, interclass correlation coefficient=0.353) CONCLUSION: K-COSI proved to be highly reliable. The results suggest that the adapted Korean version of COSI is a reliable and valid measure for Korean-speaking patients with hearing loss.

Prognostic Factors for Recovery from Sudden Sensorineural Hearing Loss: A Retrospective Study

BACKGROUND AND OBJECTIVES: This study aimed to investigate prognostic factors in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). SUBJECTS AND METHODS: From January 2007 to December 2011, a retrospective chart review identified 494 consecutive patients with ISSNHL. Demographic, audiometric, and clinical data were analyzed using a logistic regression test. RESULTS: Hearing recovery from ISSNHL was significantly associated with factors such as age, duration from onset of symptoms to commencement of treatment, severity of the initial pure tone threshold, and the treatment method. Intratympanic (IT) steroid administration alone showed a comparable efficiency to oral steroid administration with or without IT steroid injection. In patients who received IT steroid injection, the duration from onset to treatment, severity of initial hearing loss, and sequential IT steroid injection following systemic steroid administration were statistically associated with hearing improvement. CONCLUSIONS: Age, severity of initial pure tone threshold, duration from onset to treatment, initial speech discrimination, and initial pure tone threshold are statistically significant prognostic factors related to hearing improvement in ISSNHL. IT steroid injection as an initial single treatment is comparable to systemic oral steroid administration.

Clinical Application of Hyperbaric Oxygen in Treatment of Idiopathic Sudden Sensorineural Hearing Loss / 대한이비인후과학회지

Sudden sensorineural hearing loss is relatively common disease with unknown etiology. Although its etiology is unknown, it is thought to be a common pathway that leads to cochlear ischemia which leads to cochlear damage and hearing loss. Hyperbaric oxygen therapy is one of options for the treatment of sudden hearing loss which exposes patient with 1.5-3 fold sea level pressure of 100% oxygen which may reverse the ischemic condition of cochlea. According to previous studies, hyperbaric oxygen therapy is beneficial for restoring hearing level in sudden hearing loss patients especially when it is applied at early stage of onset, young age patient and profound hearing loss. Data from Asan medical center with 29 patients with idiopathic sudden sensorineural hearing loss shows 51.7% of good recovery rate after hyperbaric oxygen treatment. This treatment method however, also has minor complications and is very costly, practitioner should consider the cost-benefit before using this method.

Development of Multichannel Vestibular Prosthesis for Treatment of Bilateral Vestibular Deficiency / 대한이비인후과학회지

Bilateral loss of vestibular sensation from injuries of vestibular hair cells causes individuals suffering poor vision during head movement, postural instability, chronic disequilibrium, and cognitive distraction. A vestibular prosthesis analogous to cochlear implants but designed to modulate vestibular nerve activity during head movement should improve quality of life for these chronically dizzy individuals. An implantable prosthesis that partly restores normal activity on branches of the vestibular nerve should improve quality of life for individuals disabled by this disorder. There have been many efforts to develop and restore 3-dimensional angular vestibule-ocular reflex and the Johns Hopkins vestibular neuro-engineering laboratory has been developing a head-mounted multichannel vestibular prosthesis that restores sufficient semicircular canal function to partially recreate a normal 3-dimensional angular vestibulo-ocular reflex. In this review, their results are described.

Enhancement Pattern of the Normal Facial Nerve on Three - Dimensional (3D) - Fluid Attenuated Inversion Recovery (FLAIR) Sequence at 3.0 T MR Units

PURPOSE: To compare the enhancement pattern of normal facial nerves on 3D-FLAIR and 3D-T1-FFE-F) sequences at 3.0 T MR units. MATERIALS AND METHODS: We assessed 20 consecutive subjects without a history of facial nerve abnormalities who underwent temporal bone MRI with contrast enhancement between January 2008 and March 2009. Two neuroradiologists independently reviewed pre-/post-enhanced 3D-T1-FFE-FS and 3D-FLAIR images respectively with 2-week interval to assess the enhancement of normal facial nerves divided into five anatomical segments. The degree of enhancement in each segment was graded as none, mild or strong, and the results of 3D-FLAIR and 3D-T1-FFE-FS image sets were compared. RESULTS: On 3D-FLAIR images, one of the two reviewers observed mild enhancement of the genu segment in two (10%) subjects. On 3D-T1-FFE-FS images, at least one segment of the facial nerve was enhanced in 13 (65%) subjects. At least one reviewer found that 17 of the 100 segments showed enhancement on 3D-T1-FFE-FS images, with the mastoid segment being the most commonly enhanced. Interobserver agreement on 3D-T1-FFE-FS images was good for enhancement of the normal facial nerve (kappa= 0.589). CONCLUSION: In contrast to 3D-T1-FFE-FS, normal facial nerve segments rarely showed enhancement on 3D-FLAIR images.

The Relationship of Frequency between Tinnitus and the Maximal Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Tinnitus is most commonly accompanied by hearing loss, so there have been several studies that tried to explain that relationship and to apply it for treatment of tinnitus. In this study, we compared tinnitogram with pure tone audiometry (PTA) in order to evaluate the relationship between the frequency of tinnitus and maximal hearing loss. SUBJECTS AND METHOD: One hundred thirty one patients with pure tone-like tinnitus sensation were included in this study. After performing tinnitogram and PTA, we tried to show whether the frequency of tinnitus matched the frequency of the maximal hearing loss. After dividing the patients into two groups (group A: frequency of tinnitus not matching the frequency of the maximal hearing loss, group B: frequency of tinnitus matching the frequency of the maximal hearing loss), we studied the characteristics, including residual inhibition, of these two groups. RESULTS: In the patients, there was no significant correlation between the frequency of tinnitus and the maximal hearing loss (p=0.131). In comparing the group A and B, we could not show differences in the hearing threshold, residual inhibition, visual analogue scale, and tinnitus handicap inventory score. However, the average duration of tinnitus was statistically prolonged in Group A than in Group B (p<0.05). In addition, there were statistically significant relationships between the two frequencies in the group which show less than six month of duration (p<0.05). CONCLUSION: From this study, we could not show that a relationship existed between the frequencies of tinnitus and the maximal hearing loss.

Age Related Hearing Loss in Korea: A Healthcare Center-based Study

BACKGROUND: Age-related hearing loss is a common degenerative disorder among older individuals that warrants attention in a society with an aging population. The objectives of this study were to investigate age-related hearing loss and to estimate the prevalence of age-related hearing loss in Korea using a healthcare center-based study. METHODS: Persons older than 50 years of age visiting a selected health promotion center were recruited (n=10,118). Pure tone audiometry was performed on the subjects, and the average hearing thresholds were obtained using 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz for the six-dimension method. RESULTS: The prevalences of age-related hearing loss for subjects older than 65 years were 36.8% at a cutoff of > or =26 dBHL and 10.1% at a cutoff of > or =41 dBHL. When age and gender were corrected for, the estimated prevalences of age related hearing loss for those subjects greater than 65 years in the general population were 45.8% at a cutoff value of > or =26 dBHL and 14.8% at a cutoff value of > or =41 dBHL. CONCLUSION: Our study provides important information concerning age-related hearing loss in Korea. The estimated prevalence of age-related hearing loss in the general population in Korea was high.

Two Cases of Skull Base Osteomyelitis after Mastoidectomy / 대한이비인후과학회지

Skull base osteomyelitis is originated from inappropriately treated chronic infections near the skull base. If diagnosis and treatment are delayed, it occasionally causes multiple cranial nerve palsy, with the mortality rate being as high as 60%. Skull base osteomyelitis typically evolves as a complication of external otitis in diabetic patients, so it has been thought as a synonym for malignant external otitis. However, the routes of infection are diverse. We experienced two patients of atypical skull base osteomyelitis after mastoidectomy. It is an unusual complication of mastoidectomy, so we report about these cases.

Treatment of Meniere's Disease with Low-Concentration Intratympanic Gentamicin Injection / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Intratympanic gentamicin injection is used as one of the treatment modalities for medically intractable Meniere's disease. But the ideal dosage and concentration of gentamicin were not established in consideration of therapeutic efficacy and the risk of postoperative hearing loss. We analyzed the clinical outcome of low-concentration intratympanic gentamicin injection in patients with Meniere's disease. And we also tried to find factors anticipating for the response to treatment. SUBJECTS AND METHOD: A retrospective review was conducted on 45 subjects who had been diagnosed as 'definite' Meniere's disease (AAO-HNS, 1995) and had no response to medical treatment over 3 months in our clinic. The concentration of gentamicin was 7 mg/cc, which was very low compared with previous studies. We reviewed postoperative changes on vertigo, tinnitus and hearing by questionnaire and pure tone audiometry. We also analyzed preoperative patients' characteristics for acquisition of predictive factors of treatment response. RESULTS: Vertigo was completely disappeared in 37 (82%) patients and there was no vertigo improvement in 8 (18%) patients despite multiple injections. Tinnitus was controlled in 11 (24%) patients, and aggravated in 4 (8%) patients. A significant postoperative hearing loss over 10 dB occurred in only 6 (13%) patients. Preoperative patients' hearing threshold, frequency of vertigo, functional level and finding in electrical test, such as electrocochleogram, were not different regarding treatment response. CONCLUSION: Low-concentration gentamicin was enough to control vertigo and could reduce the risk of postoperative hearing loss in patients with Meniere's disease.

Petrous Apex Cholesterol Granuloma Presenting as Endolymphatic Hydrops: A Case Report

A petrous apex cholesterol granuloma (PACG) is the most common lesion of the petrous apex mass. Affected patients present with various symptoms such as hearing loss, vertigo, headache, tinnitus, facial spasms, and diplopia. We report the case of a 32-yr-old man with a PACG, who was first misdiagnosed with Meniere's disease. He was placed on a low-salt diet, and prescribed medication from another hospital, for several months, but the symptoms persisted and worsened. The patient presented to the emergency room complaining of left facial twitching and numbness. To rule out a central neurological lesion, temporal bone magnetic resonance imaging was carried out and a 2.5 cm mass with high signal intensity on T1- and T2-weighted imaging, without gadolinium enhancement, was found. Because of the hearing and facial problems, we drained cholesterol-bearing material via an infralabyrinthine approach using a computer aided image-guided surgical device, the BrainLAB(R). After the operation, the vertigo and hearing loss were no longer present. It is likely that the patent's Meniere's disease-like symptoms were due to the compression of the endolymphatic sac by a PACG.

The Application of Diagnostic Tools of Central Auditory Processing Disorder and Their Normative Value in Each Age Group in Korean / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: To develop and apply a diagnostic test tool for central auditory processing disorder (CAPD) and to obtain normative data of Korean subjects with normal hearing. SUBJECTS AND METHOD: After obtaining the approvement of the Institution Review Board of Asan Medical Center for this clinical study, we conducted this study for 135 subjects with normal hearing. Frequency & duration pattern tests and dichotic test were administered to subjects with normal hearing were evaluated by pure tone audiometry. Patients were separated into the following age categories:up to and including 7-year-olds, 8- and 9-year-olds, 10- and 11-year-olds, 12- to 18-year-olds and adults over 18. RESULTS: The frequency pattern test showed that the mean score was 14.4+/-7.1, 19.7+/-9.2, 23.8+/-8.6, 24.1+/-7.0 and 28.5+/-2.7, for each age category, respectively. The duration pattern test showed that the mean score was 13.8+/-6.2, 17.0+/-6.1, 21.6+/-5.4, 25.6+/-4.3 and 28.4+/-2.1, respectively. The dichotic test showed that the right mean scores were 26.5+/-3.2, 27.0+/-3.2, 27.8+/-3.2, 29.4+/-0.9, 27.9+/-1.5 and left the mean scores 26.4+/-3.7, 27.0+/-2.6, 28.6+/-1.4, 28.6+/-1.3, 27.9+/-1.6 for each age category, respectively. CONCLUSION: We obtained the normative data of Korean subjects for the diagnosis of CAPD. Additional diagnostic tools and treatment methods must be developed continuously.

Postoperative Results of Ossiculoplasty over Stapes Head / 대한이비인후과학회지

BACKGROUD AND OBJECTIVES: Incus erosion with intact stapes head was most common ossicular impairment in chronic otitis media. Here, we aimed to investigate hearing and clinical results of the ossiculoplasties when the stapes head was intact. SUBJECTS AND METHOD: We analyzed 281 patients of ossiculoplasties over stapes head performed from 1990 to 2005. Patients were divided into 3 groups: Si group (n=121) included patients with interposition of prosthesis between malleus and stapes; Sc-PORP group (n=99) included patients with columellarization between tympanic membrane and stapes head with PORP; Sc-SC group (n=61) included patients with columellarization with the autologous materials between tympanic membrane and stapes head. Hearing improvement and extrusion rates of three groups were analyzed. RESULTS: At 6 months after the surgery, the postoperative air-bone gap (ABG) level within 20 dB was 45%, 44%, 25% in Si, Sc-PORP, Sc-Sc, respectively. The closure of ABG was statistically better in Si and Sc-PORP compared with Sc-SC. In canal wall-up mastoidectomy, Sc-PORP showed better hearing results than Si, while Si was better than Sc-PORP in canal wall-down mastoidectomy. At 36 months after the surgery, extrusion-free survival according to the type of ossiculoplasty were 100%, 89.6%, 100% in Si, Sc-PORP, Sc-SC, respectively. CONCLUSION: Si and Sc-PORP provide good hearing results. However, Si has lower extrusion rates than Sc-PORP and remains stable over time.

Apoptotic Pattern of Cochlear Outer Hair Cells and Frequency-specific Hearing Threshold Shift in Noise-exposed BALB/c Mice

OBJECTIVES: Apoptosis of outer hair cell (OHC) can be identified through nuclear staining by specific nuclear changes. The change of filamentous actin (F-actin) is also involved in early cell death process. The study was designed to investigate OHC death along the whole length of the organ of Corti. METHODS: BALB/c hybrid mice were used in this study. The noise group was exposed to white noise of 120 dB SPL for 3 hr per day for 3 consecutive days. The tone burst auditory brainstem response (ABR) test was conducted and cochleas from each group were obtained for the immunostaining of FITC phalloidin for F-actin and propidium iodide (PI) for nuclei. RESULTS: ABR threshold of the noise group significantly increased after noise exposure (P<0.001). No threshold shift was found in the control group. Threshold shift of the noise group constantly increased from 4 to 16 kHz, but threshold shifts at 16 kHz and 32 kHz were similar. Patterns of OHC staining were subclassified as FITC+PI- cells, FITC+ PI+ cells, FITC-PI+ cells and missing cells. Proportion of normal live OHCs (FITC+PI-) rapidly decreased from the apex to the base. In the basal turn, FITC-PI+ cells and vacancy OHC (missing cells) were observed easily. Apoptotic and missing cells were most abundant at 60% of the whole length of the Corti organ. CONCLUSION: We could subclassify morphologic changes in OHC death after noise exposure. Quantitative changes in OHCs along the whole Corti organ showed a plateau pattern similar to that of a frequency-specific threshold shift.

Multicenter study on the treatment pattern of Meniere'sdisease in Korea

BACKGROUND AND OBJECTIVES: It is hard to determine the efficacy of several treatment options of Meniere's disease since dynamic course of the disease and diverse rate of recurrence. Few modalities are regarded as 'effective' in the viewpoint of evidence based medicine. Study was conducted to know the current status of treatment options for Meniere's disease. MATERIALS AND METHODS: A multicenter survey was conducted using questionnaires to collect information on current status of treatment patterns in Meniere's disease. The questionnaire answered by neurotologic surgeons working at 12 institutes in Korea was analyzed. RESULTS: Low salt diet was always instructed to their patients, but 8 out of 12 responders (67%) did not emphasis on the amount of dietary salt. Duration of pharmacotherapy was ranged from 3 to 12 months. Intratympanic steroid injection was performed in 8 institutes (67%). Every institute agreed on the role of intratympanic gentamicin application. Treatment options for intractable patients were asked. Endolymphatic sac surgery, intratympanic steroid, Meniette device and intratympanic aminoglycoside injection were answered in patients who hope to preserve residual hearing. On the contrary, in patients without serviceable hearing, intratympanic jnjection of aminoglycosides (9/12, 75%) dominated as the next treatment option. CONCLUSIONS: Most institutes provide similar patterns of practice in medical treatment. The application of intratympanic aminoglycoside is also agreed in intractable patients without serviceable hearing. However, thoughts about the role and detailed methods of the surgical and adjunctive treatment options were not agreed, especially in intractable patients with good hearing. Further clinical studies and discussions would be necessary to provide consensus for the best treatment of Meniere's disease in Korea.

Clinical Comparison of the Auditory Steady-State Response with the Click Auditory Brainstem Response in Infants

OBJECTIVES: Our goal was to determine the effectiveness of using the auditory steady state response (ASSR) as a measure of hearing thresholds in infants who are suspected of having significant hearing loss, as compared with using the click-auditory brainstem response (C-ABR). METHODS: We retrospectively analyzed the audiologic profiles of 76 infants (46 boys and 30 girls, a total of 151 ears) who ranged in age from 1 to 12 months (average age: 5.7 months). The auditory evaluations in 76 infants who were suspected of having hearing loss were done via the C-ABR and ASSR. In addition, for reference, the mean ASSR thresholds were compared to those of 39 ears of infants and 39 ears of adults with normal hearing at 0.5, 1, 2, and 4 kHz. RESULTS: The highest correlation between the C-ABR and ASSR thresholds was observed at an average of 2-4 kHz (r=0.94). On comparison between the hearing of infants and adults at 0.5, 1, 2, and 4 kHz, the mean ASSR threshold in infants was 12, 7, 8, and 7 dB higher, respectively, than that in adults. CONCLUSION: ASSR testing may provide additional audiometric information for accurately predicting the hearing sensitivity, and this is essential for the management of infants with severe to profound hearing loss.

The Validity Using Two-stage Automated Auditory Brainstem Response as a Universal Newborn Hearing Screening Protocol : Experiences in Asan Medical Center / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Universal newborn hearing screening is widely accepted due to socioeconomic harm of congenital hearing loss. The aim of this study was to assess whether two-stage automated auditory brainstem response (AABR) is acceptable method for newborn hearing screening and to check the presence of potential false negative cases by using another criterion considering sweep number. SUBJECTS AND METHOD: Among 3761 neonates who were born from March 2004 to December 2005, 3053 healthy neonates (81.18%) whose parents agreed to hearing screening protocol were screened with AABR. Failed neonates ('refer') at first stage test and neonates showing high sweep number (>4000) on repeated test were received second stage retest within 24 hours from the first test. Neonates whose retest AABR results were failed or high sweep number continuously were tested with conventional ABR as a confirmative study within 3 months. RESULTS: 94 neonates (3.08%) were failed and 180 neonates (5.89%) showed high sweep number on first stage AABR test. On second stage AABR test, neonates with 'final refer' result were 46 (1.51%) and neonates with 'final high sweep number' result were 44 (1.44%). Neonates with threshold of over 30 dB at ABR were 14 among final refer group and 5 among final high sweep number group. Three bilateral profound hearing loss cases were detected and proper management was done. Nine false negative cases were detected and of these, 3 neonates showed moderate hearing loss. There is no clear relationship between predicting false negative case and sweep number. CONCLUSION: Our current two stage AABR test is useful tool for newborn hearing screening with acceptable referral rate and positive predictive value. False negative cases detected through our protocol have no clear relationship with high sweep number.