Prevalence and etiology of hearing loss in rural Nicaraguan children

OBJECTIVE/HYPOTHESIS: The prevalence and causes of pediatric hearing loss (HL) in the developing world are largely unknown. Infectious sequelae, ototoxic medications, and genetic causes may play a larger role in developing countries. In addition, the significance of GJB2 mutation gene in poorly developed areas remains unclear. The intent of this study is to investigate the prevalence and etiology of HL in children living in a remote, impoverished region of northern Nicaragua. STUDY DESIGN: Cross-sectional study. METHODS: Clinical data from two sources were analyzed: data from screening examinations performed in rural schools in the Department of Jinotega, Nicaragua (group A) and pediatric HL patients seen at the Otolaryngology and Audiology Clinic in Jinotega, Nicaragua (group B). Patients with congenital HL were offered a genetic test for GJB2 mutations. Comparisons were made using parametric (analysis of variance) and nonparametric (Kruskal-Wallis) tests. RESULTS: School-based screening examinations (group A) revealed a high prevalence of significant HL (>30 dB) of 18%. The majority of these children had normal otoscopic examinations (58%). A family history of HL was seen in 24% of children who failed screening exams. Positive family history was more common in patients with HL (P < .01) and in specific schools (P < .05). Clinic-based evaluations (group B) reveal a population with predominantly severe-profound HL. Physical dysmorphism was common, yet identifiable syndromic HL was rare. Although familial HL was common (33%), there were no pathologic GJB2 mutations. Other common risk factors in this population were maternal infection during pregnancy, neonatal distress, low birth weight or prematurity, and gentamicin exposure. CONCLUSIONS: HL in this rural, third world environment is more prevalent, and the etiologies responsible in this study group are different from those encountered in industrialized nations. Poor perinatal health care, infectious causes, gentamicin exposure, and hereditary HL are potentially preventable causes that play a major role in this population.     

Is there any association between consanguinity and hearing loss

BACKGROUND: Hearing loss (HL) and its complications appear to be increasingly common in developing countries. Previous studies have supported the association between hearing loss and consanguinity. OBJECTIVE: The aim of the present study was to determine the frequency of hearing loss and its association with consanguinity among Qatari population. In addition, correlation between hearing loss and Rhesus (Rh) blood groups has been investigated. DESIGN: This is a cross-sectional study. SETTING: The study conducted at the Hamad General Hospital, Hamad Medical Corporation. SUBJECTS: Total sample of 2800 infants screened and 2277 subjects were eligible to be included in the study. METHODS: The neonatal screening for hearing loss was conducted from January 2003 to November 2003 among all the 2800 infants born during that period. Some of them were admitted to neonatal intensive care unit (NICU). The hearing loss was screened using otoacoustic emission (Garson Stadler Incorporation, GSI-70), auditory brain stem responses (ABR) and tympanogram. RESULTS: Out of 2277 infant screened, the prevalence of hearing loss was (119/2277) 5.2%. The prevalence of HL was more common in boys (2.7%) than in girls (2.5%). We did not find any statistical significance differences between genders with the respect of HL. Parental consanguinity was more common among HL cases compared with non-HL 60.5% versus 25.3% (p < 0.0001). Family history of hearing loss did not show any differences between the two groups. 4.2% versus 4.3%. Risk factors like caesarean section, prenatal smoking and prenatal high blood pressure did not show any significant differences between the two groups. However, admission to NICU is associated with increase prevalence of HL 8.4% versus 4.4% (p = 0.043). The present study revealed that strong correlation between hearing loss, consanguineous (r = 0.217, p < 0.01), father education level illiterate (r = 0.293, p < 0.01), mothers consanguineous (r = 0.206, p < 0.01), mothers educational level illiterate (r = 0.228, p < 0.01), mother blood group positive (r = 0.476, p < 0.01), family history of HL among first or second degree of relatives (r = 0.620, p < 0.01) and father hypertension (r = 0.570, p < 0.01). Furthermore, a significant correlation between hearing loss and Rh blood groups has been discovered. CONCLUSION: The present study was directed at determining the prevalence and risk factors of HL in the infant population of Qatar. The data revealed that parental consanguinity was more common among hearing loss cases. There is a strong correlation between hearing loss and baby's age.     

Spatial hearing disability after acoustic neuroma removal

OBJECTIVES/HYPOTHESIS: Previous studies on hearing loss (HL) after acoustic neuroma removal concentrate mainly on pure-tone hearing results rather than hearing disability. Our objectives were to use the Speech, Spatial and Qualities of Hearing scale (SSQ), a comprehensively validated questionnaire, to characterize and quantify the auditory disabilities that patients experience with a profound unilateral HL after acoustic neuroma removal. STUDY DESIGN: Forty-four patients with profound unilateral HL after acoustic neuroma surgery completed the SSQ. Their findings were compared with those of a control population sample matched for age, sex, and hearing level in the better hearing ear. RESULTS: In comparison with controls, with use of analysis of variance, acoustic neuroma patients scored poorly on all items except for the identification of sounds and objects (P = .123). The greatest difficulties involved speech in the presence of noise, situations of multiple speech-streams and switching (such as listening to someone speaking and the television at the same time), the location of unseen objects, and increased listening effort (P < .05). CONCLUSION: This study demonstrates that, compared with a control population, these patients experience a significant range of auditory disabilities. It is important that clinicians be aware of the impact of such a profound unilateral HL and its potential to affect daily life. Patient counseling prior to surgery is essential, especially in patients whose loss of binaural hearing could constitute a major disability.     

Neonatal hearing screening in a neonatal intensive care unit using distortion-product otoacoustic emissions

OBJECTIVE: To determine pass and refer rates, and identify risk factors relating to refer responses, in neonates screened using distortion-product otoacoustic emissions (DPOAEs). MATERIAL AND METHODS: A total of 435 neonates admitted to the neonatal intensive care unit (NICU) of the Philippine General Hospital between May and October 2000 were screened using DPOAEs within 48 h of admission. RESULTS: The male:female ratio in the sample was 1.05. In total, 56% of neonates were born preterm, the mean birthweight was 2,428.39 +/- 710.39 g and 8.9% weighed < 1,500 g. In total, 47.9% were delivered by Caesarian section and 44.9% were delivered vaginally. Almost 14% of neonates had 1-min Apgar scores of < 6, and 4% had 5-min Apgar scores of < 7. Approximately 95% of neonates had a poor perinatal history. Using pediatric aging it was noted that 46% of these neonates were born preterm. and 30.4% were small for gestational age. At least one neonatal disease was found in 42% of neonates, whilst 95.7% had to be given medication. The bilateral refer rate was 29.1%. Two-by-two analysis of risk factors for hearing loss and DPOAE measurements showed that only male sex seemed to have a significant association with a refer response. Neonates weighing < 1,500 g at birth showed a marginally significant association with a refer response (p = 0.07). All other neonates showed no crude association with DPOAE measurements. CONCLUSION: These preliminary data show that a high proportion of NICU patients may have poor outer hair cell function, and thus poor hearing. In order to develop an effective neonatal hearing screening program, further studies of prevalence and risk factors should be pursued in the same setting.     

Hearing screening of infants in Neonatal Unit, Hospital Universiti Sains Malaysia using transient evoked otoacoustic emissions

The objective of this prospective study was to report on the prevalence of hearing impairment in the neonatal unit population. From 15 February 2000 to 15 March 2000 and from 15 February 2001 to 15 May 2001, 401 neonates were screened using transient evoked otoacoustic emissions (TEOAE) followed by second-stage screening of those infants who failed the initial test. Eight (2 per cent) infants failed one ear and 23 (5.74 per cent) infants failed both ears, adding up to 7.74 per cent planned for second-stage screening. Five out of 22 infants who came for the follow up failed the screening, resulting in a prevalence of hearing impairment of 1 per cent (95 per cent confidence interval [95% CI]: 0.0-2.0). Craniofacial malformations, very low birth weight, ototoxic medication, stigmata/syndromes associated with hearing loss and hyperbilirubinaemia at the level of exchange tranfusion were identified to be independent significant risk factors for hearing impairment, while poor Apgar scores and mechanical ventilation of more than five days were not. In conclusion, hearing screening in high-risk neonates revealed a total of 1 per cent with hearing loss. The changes in the risk profile indicate improved perinatal handling in a neonatal population at risk for hearing disorders.     

Neonatal hearing screening with transient evoked otoacoustic emissions in Western Saudi Arabia

OBJECTIVE: To study the incidence of congenital hearing impairment in the Saudi population and to evaluate the need of establishing a Saudi universal neonatal hearing screening program based on transient evoked otoacoustic emission. METHODS: A total of 11986 well non-high-risk neonates were screened by transient evoked otoacoustic emission over period of 8 years from September 1996 to February 2004. The universal hearing screening was consequently done in a daily base before discharge from nursery. Those who failed the initial screening were followed up diagnostically until hearing loss was confirmed or excluded. RESULTS: From the total number of 11,986 neonates (41.4% male and 58.6% females) examined in this study 10943 (91.3%) neonates passed the first screening step while 1043(8.7%) neonates failed. From the 1043 neonates examined in the second screening step in the 5th day of life, 300 (29%) neonates failed. At the age of 5 months, all the 300 infants that failed the second screening step underwent a comprehensive audiological assessment to confirm the existence of hearing loss. The 278 infants that passed the assessment were considered as normal; while 22 failed and were confirmed to have congenital hearing loss. Of these 22 infants, 2 had unilateral sensorineural hearing loss, and the remaining 20 had bilateral sensorineural hearing loss. The incidence of sensorineural hearing loss was estimated to be 0.18% while the incidence of bilateral sensorineural hearing loss was 0.17%. No significant difference between males and females was found. The average age at confirmation of congenital hearing loss was 5.5 months. CONCLUSION: The incidence of congenital hearing loss in the western region of Saudi Arabia is relatively high compared with international figures. Hearing screening for all neonates using transient evoked otoacoustic emission should be part of the standard medical care in Saudi Arabia.     

High incidence of GJB2 mutations during screening of newborns for hearing loss in Austria

OBJECTIVES: The aim of the present study was to evaluate gap junction protein beta2 (GJB2) genetic testing within a national neonate screening program for hearing loss (HL) in a European population. DESIGN: Neonatal cases of nonsyndromic HL (N = 21) were identified by postpartal otoacoustic emissions (OAE) and brain stem electric response audiometry (BERA) analysis. GJB2 testing was performed by direct sequencing. RESULTS: Mutations in GJB2 were found in 15 of 21 children (71.4%) identified by neonatal audiological screening. The 35delG mutation in GJB2 was found homozygous in 10 cases (47.6%) and also as a clear cause of HL as the heterozygous alterations 35delG/del311-324 and 35delG/L90P. In a single case, L90P/R143Q was also identified as a cause of HL. In 3 HL cases that were not identifiable during initial OAE testing, homozygous 35delG and 35delG/R184P defined the genetic basis for HL in 2 cases, whereas one case had wild-type GJB2. CONCLUSIONS: Our findings of the high mutation rate in the Austrian population, especially in neonates identified during the newborn screening program, confirm the importance of screening for mutations in GJB2.     

Epidemiology of congenital hearing loss in Victoria, Australia

The aim of this study was to report the incidence, prevalence and clinical characteristics of congenital hearing loss sufficient to require hearing aid fitting in the first 6 years of life for the 1993 birth cohort of the state of Victoria (population 4.4 million), Australia. In 1993, 64,116 infants born in the state of Victoria survived the neonatal period. Subjects included all children with congenital hearing loss for which hearing aids were fitted, at any time up to and including 31 December 1999, when the youngest member of the cohort reached 6 years of age. Data on the degree, type and etiology of hearing loss were available from the Australian Hearing database for all subjects. Sociodemographic and health data were available from the Victorian Infant Hearing Screening Program (VIHSP) and parent questionnaires. The known prevalence of identified congenital hearing loss increased as the cohort aged. By the time the youngest member had reached the age of 6 years, 134 children (78 boys, 56 girls) had been fitted with hearing aids for permanent congenital hearing loss of any degree (2.09/1000). Fifty-four (40%) of these had known mild losses (20-40 dB HL). The prevalence of known moderate or greater loss (> 40 dB HL) was 1.12/1000; the data suggest that over 90% could have been detectable by neonatal hearing screening. A further seven children from the birth cohort were fitted with hearing aids due to acquired forms of hearing loss (0.11/1000). The etiology was known in only 57 (43%) congenital cases, with known non-syndromal genetic causes accounting for 21 (37%) of these. This study reports on the prevalence of congenital hearing loss requiring hearing aid fitting for an entire birth cohort. These data indicate the possible yield from neonatal screening, and hence the likely benefit of such screening. For a large proportion of cases, the etiology remains unknown. These data have implications for health service delivery and illustrate the usefulness of a population database in monitoring the prevalence of congenital hearing loss.     

Results of one year's application of a universal protocol for the early detection of hearing loss in neonates

These are the results of the first year of the application of a universal programme for the early detection of neonatal deafness. Our objective is making a diagnosis of all the unilateral or bilateral cases of hearing loss above 35 dB HL, before the age of 6 months. The detection strategy has 2 screening phases with transient evoked otoacoustic emissions (TEOAE) and one diagnostic phase with auditory brain stem response (ABR). The ABR were carried out both on those patients that failed the TEOAE screening and on the neonates with hearing loss risk factors. Of the 1,277 living newborn babies (NB), we evaluated 94%. 3.3% of the NB showed hearing loss risk factors. 90% of the NB passed the first TEOAE in both ears and, after the second TEOAE, only 2.5% of the NB reached the diagnostic phase. We provided early detection and treatment of 0.58% of cases of bilateral severe-deep hearing loss. Finally, the results obtained are examined together with the importance of planning universal hearing screening.     

Esthesioneuroblastoma and Cervical Lymph Node Metastases: Clinical and Therapeutic Implications

Objective – To determine pass and refer rates, and identify risk factors relating to refer responses, in neonates screened using distortion-product otoacoustic emissions (DPOAEs). Material and Methods – A total of 435 neonates admitted to the neonatal intensive care unit (NICU) of the Philippine General Hospital between May and October 2000 were screened using DPOAEs within 48 h of admission. Results – The male:female ratio in the sample was 1.05. In total, 56% of neonates were born preterm, the mean birthweight was 2428.39±710.39 g and 8.9% weighed <1500 g. In total, 47.9% were delivered by Caesarian section and 44.9% were delivered vaginally. Almost 14% of neonates had 1-min Apgar scores of <6, and 4% had 5-min Apgar scores of <7. Approximately 95% of neonates had a poor perinatal history. Using pediatric aging it was noted that 46% of these neonates were born preterm, and 30.4% were small for gestational age. At least one neonatal disease was found in 42% of neonates, whilst 95.7% had to be given medication. The bilateral refer rate was 29.1%. Two-by-two analysis of risk factors for hearing loss and DPOAE measurements showed that only male sex seemed to have a significant association with a refer response. Neonates weighing <1500 g at birth showed a marginally significant association with a refer response (p=0.07). All other neonates showed no crude association with DPOAE measurements. Conclusion – These preliminary data show that a high proportion of NICU patients may have poor outer hair cell function, and thus poor hearing. In order to develop an effective neonatal hearing screening program, further studies of prevalence and risk factors should be pursued in the same setting.     

Newborn hearing screening in the limiar clinic in Porto Velho Rondônia

With the universal hearing screening we can prevent auditory disorders in children.AimTo characterize the program of neonatal auditory screening into a population of neonates.Materials and Methodslongitudinal cohort study. We surveyed the clinic's database on neonatal auditory screening in the city of Porto Velho, Rondônia.ResultsAmong the 6,889 newborns in the database, 5,700 (82.7%) passed and 1,189 (17.3%) failed the first screening. Of the group which failed 900 (75.7 %) returned for retesting. Among these, 15 (0.22 %) newborns had hearing loss confirmed. The most prevalent was neural hearing loss with 46.7% confirmed cases; they had hyperbilirubinemia as the most prevalent risk factor.Conclusionhyperbilirubinemia was the most prevalent risk factor found in the group of hearing impaired children. The prevalence of hearing loss was of 2 in 1,000 newborns. It is important to highlight the relevant association between neural hearing loss caused by hyperbilirubinemia and sensorineural hearing loss of unknown causes.     

Prevalence of hearing impairment in a population in Sweden

An epidemiological study was carried out, based on 590 randomly selected subjects, aged from 20 to 80 years, in the province of Osterg?tland in Sweden. The results obtained were similar to published results from other countries, with an overall prevalence of subjects with average hearing threshold levels over the frequencies 0.5, 1, 2 and 4 kHz (M4) equal to or exceeding 25 dB HL for the better ear (BE) of 16.9% (95% CI: 13.819.9%). For M4 BE > or = 35 dB HL, the prevalence was 7.7% (95% CI: 5.5-9.8%), for M4 BE > or = 45 dB HL, the prevalence was 3.3% (95% CI: 1.9-4.8%), and for M4 BE > or = 65 dB HL, the prevalence was 0.2% (95% Cl: 0.0-0.6%). The overall prevalence of reported tinnitus was 13.2% (95% CI: 10.5-16.0%). In the population under study, 7.7% of the subjects were estimated to benefit from a hearing aid, while the prevalence of hearing aid users was 2.4%.     

Epidemiology of congenital hearing loss in Victoria,Australia: Epidemiología de la hipoacusia congénita en Victoria,Australia

The aim of this study was to report the incidence, prevalence and clinical characteristics of congenital hearing loss sufficient to require hearing aid fitting in the first 6 years of life for the 1993 birth cohort of the state of Victoria (population 4.4 million), Australia. In 1993 64 116 infants born in the state of Victoria survived the neonatal period, Subjects included all children with congenital hearing loss for which hearing aids were fitted, at any time up to and including 31 December 1999, when the youngest member of the cohort reached 6 years of age. Data on the degree, type and etiology of hearing loss were available from the Australian Hearing database for all subjects. Sociodemographic and health data were available from the Victorian Infant Hearing Screening Program (VTHSP) and parent questionnaires. The known prevalence of identified congenital hearing loss increased as the cohort aged. By the time the youngest member had reached the age of 6 years, 134 children (78 boys, 56 girls) had been fitted with hearing aids for permanent congenital hearing loss of any degree (2.09/1000). Fifty-four (40%) of these had known mild losses (20–40 dBHL). The prevalence of known moderate or greater loss (>40 dB HL) was 1.12/1000; the data suggest that over 90% could have been delectable by neonatal hearing screening. A further seven children from the birth cohort were fitted with hearing aids due to acquired forms of hearing loss (0.11/1000). The etiology was known in only 57 (43%) congenital cases, with known non-syndromal genetic causes accounting for 21 (37%) of these. This study reports on the prevalence of congenital hearing loss requiring hearing aid fitting for an entire birth cohort. These data indicate the possible yield from neonatal screening, and hence the likely benefit of such screening. For a large proportion of cases, the etiology remains unknown. These data have implications for health service delivery and illustrate the usefulness of a population database in monitoring the prevalence of congenital hearing loss.     

Newborn hearing screening: effectiveness, importance of high-risk factors, and characteristics of infants in the neonatal intensive care unit and well-baby nursery.

BACKGROUND: In contrast to the recommendations of the Joint Committee on Infant Hearing, neonatal hearing screening programs are still not universally available, and many countries implement elective screening in high-risk newborns. OBJECTIVE: To assess the failure rates of neonates in hearing screening and the relative importance of risk factors for hearing impairment, both in neonatal intensive care units and in well-baby nursery neonates. The impact on cost-effectiveness is also evaluated. SUBJECTS: In the current study, 25,288 newborns were assessed; 23,574 were full-term newborns in the well-baby nursery and 1,714 neonates were in neonatal intensive care units. METHODS: All neonates had a general examination (including assessment for congenital anomalies and related history) and were assessed using transient evoked otoacoustic emissions. All newborns were older than 36 weeks at examination and thus had reliable transient evoked otoacoustic emissions. RESULTS: From the 23,574 full-term neonates in the well-baby nursery, 23,123 (98.1%) passed the test and 451 failed (1.9%). Fifty-three of the 23,574 neonates (0.2%) had a risk factor for hearing impairment; 44 (83%) passed the test and 9 failed (17%). Family history of congenital hearing loss and congenital anomalies were the most frequent risk factors for hearing loss. From the 1,714 neonates in neonatal intensive care units, 1,590 (93%) passed the test and 124 failed (7%). Two hundred thirty-two of the 1,714 neonates (14%) had a risk factor for hearing impairment; 205 (88%) passed the test and 27 failed (12%). In neonatal intensive care unit neonates, toxic levels of ototoxic drugs, mechanical ventilation for more than 24 hours, prematurity, and low birth weight were the most frequent risk factors for hearing loss. Congenital anomalies/syndromes were the most important risk factors for failing screening in both the neonatal intensive care unit and the well-baby nursery, as they showed the highest risk of failing hearing screening. The second most important factor in neonatal intensive care unit newborns was low birth weight, and the third was prematurity in relation to the possibility of failing hearing screening. CONCLUSION: The present study found 575 neonates failing hearing screening of 25,288 tested newborns (2.3%). The fact that 78% of newborns who failed hearing screening were in the well-baby nurseries further supports the necessity of universal hearing screening instead of selective screening in neonatal intensive care units, even with the obvious impact on cost-effectiveness. Even if limited funding lead to selective screening in neonatal intensive care units, this should not be applied to high-risk newborns but to all neonatal intensive care unit neonates. Continuous assessment of risk factors and the related possibility of failing hearing screening are of paramount importance in designing hearing screening programs and refining the respective criteria.     

Auditory screening in neonates by means of transient evoked otoacoustic emissions: a report of 2,842 recordings.

The principal goal of an early identification program is to identify hearing impairment present at birth, in order to effect appropriate intervention as early as possible. Although recent research provides some evidence for the value of transient evoked otoacoustic emissions (TEOAEs) in neonate hearing screening, data are needed from large-scale clinical evaluations about the value of using TEOAEs for screening not only high-risk but also healthy neonates. A cohort of 1,421 neonates (2,842 ears) from the well-baby nursery was screened with TEOAEs in a 2-stage process. Neonates were referred from the first test prior to being discharged from the hospital. Those who failed were rescreened before the end of the first month. Those who did not pass the second-stage TEOAE screening were referred for diagnostic audiological evaluation for confirmation of hearing loss. Neonates transferred to a neonatal intensive care unit were not included in this study. Two neonates with bilateral sensorineural hearing loss of >40 dB hearing level were identified from this cohort. This study demonstrates the feasibility and the limitations of using TEOAEs as a universal hearing screening tool for all neonates. It confirms that the prevalence of hearing impairment in neonates has to be taken into account, even in a group of children without high-risk criteria. In France, a prevalence of 1.4 per 1,000 would represent 1,000 deaf children born every year, with reference to about 700,000 births per year. This study suggests that such universal screening programs would substantially increase the rate of early-identified infants with significant hearing impairment.     

新生儿听视同步筛查的临床模式

目的探索新生儿听力、眼病同步筛查的可行性和临床模式；了解新生儿听力下降及眼病的发病情况。方法在母婴同室应用瞬态诱发耳声发射，新生儿重症监护病房采用两阶段筛查技术进行新生儿听力筛查；同步进行新生儿眼病筛查。听力复筛未通过者，生后3个月进入诊断程序并进行跟踪随访和定期的听力学评估；眼病筛查疑似病例及时转诊到专业眼科进一步确诊。结果自2002年10月1日至2005年4月30日在济南市妇幼保健院共出生16800例新生儿，对其中的15398例（91．7％）新生儿进行了听力、眼病同步筛查。新生儿听力损失在同步筛查儿中的检出率：双耳0．312％（48／15398），单耳0．227％（35／15398）；有4例单耳或双耳先天性感音神经性聋伴发眼病或眼部阳性体征：1例极重度感音神经性聋（双）、听神经病伴双眼先天性完全性白内障，1例轻度感音神经性聋（双）伴发左眼永存瞳孔膜，1例轻度感音神经性聋（双）伴双眼底静脉扩张，1例右耳轻度感音神经性聋伴双眼永存玻璃体动脉。在15398例统计取样的新生儿中，共检出先天性眼病或眼部阳性体征13种2211例。结论新生儿期听力损失和眼病或眼部阳性体征在临床中并不少见。新生儿听视同步筛查在听力下降以及眼病监测和防治中是可行的，亦是有效的。     

Sensorineural hearing loss among sickle cell disease patients from southern Brazil

PURPOSE: A case-control study was done to confirm the higher prevalence of sensorineural hearing loss (SNHL) among sickle cell patients (HbSS) from southern Brazil. PATIENTS AND METHODS: Twenty-eight patients and 28 matched normal controls were studied. Besides complete anamneses and physical otolaryngological examination, all individuals had audiometric and tympanometric testings to determine the presence of SNHL or middle ear problems. The only significant difference between groups was the presence of a positive history of otologic symptoms (hearing loss, dizziness or tinnitus) and neurological sequelae in the HbSS patients. RESULTS: Six patients (21.4%) presented with SNHL compared with one control (3.6%) (Fisher's one-tailed P = .05; OR, 7.36 (95% CI, 0.82, 65.83). The average age of HbSS diagnosis was higher among the patients with SNHL (10 years +/- 8.3) than those without SNHL (5.43 years +/- 5.65), but this was not significant (analysis of variance P > .05). More patients 25 years and older on the examination date had SNHL than younger patients (Fisher's 2-tailed P < .05). Sixty-seven percent of the patients with SNHL had alterations in the acoustic reflex, and a surprising 27% of the patients without NSHL also presented with some elevation or an absence of acoustic reflex. CONCLUSIONS: These data indicate that patients with HbSS from southern Brazil are more predisposed to the development of sensorineural hearing problems than the general population.     

Temporal bone abnormalities associated with hearing loss in Waardenburg syndrome

OBJECTIVES/HYPOTHESIS: The objectives were to correlate audiometric thresholds with radiological findings and to determine the prevalence of inner ear radiological abnormalities in patients with hearing loss and Waardenburg syndrome. STUDY DESIGN: The study was a retrospective review of patients with Waardenburg syndrome identified in a pediatric hearing-impaired population and human genetics clinic. METHODS: Nine children with Waardenburg syndrome were identified. Eighty-nine children without sensorineural hearing loss served as control subjects. Clinical data, audiometric thresholds, and radiographic temporal bone measurements in these children were analyzed. RESULTS: Seven children were identified with hearing loss and Waardenburg syndrome. Four children had Waardenburg syndrome type 1, and three children had Waardenburg syndrome type 2. The overall prevalence of hearing loss in the total study population with Waardenburg syndrome was 78%. The mean pure-tone average was 99 dB. All of the children had sensorineural hearing loss. The hearing outcome was stable in 86% of the children. Twelve temporal bones were available for radiological analysis by computed tomography. Enlargement of the vestibular aqueduct was found in 50% of the CT scans. There was a significant difference in measurements of vestibular aqueduct width at the midpoint between the patients with Waardenburg syndrome and the control group (P <.05). There were also significant differences in the measurements of the vestibule (P =.0484), internal auditory canal (P =.0092), and modiolus (P =.0045) between the children with Waardenburg syndrome and the control group. CONCLUSION: A profound sensorineural hearing loss was characteristic of the study population with Waardenburg syndrome. Overall, 100% of patients with hearing loss and Waardenburg syndrome had temporal bone anomalies on at least one measurement of their inner ear, and 50% had an enlargement of the vestibular aqueduct at the midpoint. As shown by computed tomography, enlargement of the vestibular aqueduct and the upper vestibule, narrowing of the internal auditory canal porus, and hypoplasia of the modiolus are features of Waardenburg syndrome.     

Vestibular-evoked myogenic potentials in infancy and early childhood

OBJECTIVE: Hearing impairment and the often concurrent loss of vestibular function, which is rarely assessed in infants, can both impair sensory integration critical to the development of normal motor coordination. This study demonstrates, for the first time, that vestibular function in infants can be noninvasively assessed using vestibular-evoked myogenic potentials (VEMPs). Our intentions were to demonstrate that VEMPs can be reliably recorded from neonates and to compare neonatal VEMPs with those obtained from normal adults. STUDY DESIGN: Prospective cohort study. METHODS: Myogenic evoked potentials induced by air- and bone-conducted auditory stimuli were recorded from the sternocleidomastoid muscles of 12 normal neonates and 12 neonates with various clinical findings. These included infants with bilateral atresia of the external auditory canals, Treacher-Collins syndrome, and neonates who failed universal neonatal screening. RESULTS: With the exception of one patient with hearing loss, reproducible biphasic VEMPs were recorded from the sternocleidomastoid muscle of all the infants using loud, short tone-burst sounds. CONCLUSIONS: The VEMP has characteristics that differentiate it from the postauricular response and the Jaw reflex. The VEMPs were dominant on the side ipsilateral to the stimulated ear. The overall morphology of the neonatal VEMP is quite similar to that of adults. The major neonatal differences are a shorter latency of the n23 peak and higher amplitude variability. Our results suggest that recording of the VEMP in neonates with various audio-vestibular problems provides useful information about vestibular function in this population and may provide information that leads to better care and rehabilitation for neonates at risk of developmental and motor system delay.     

严重高胆红素血症新生儿的听力学特征

目的探讨严重高胆红素血症新生儿的听力学特点及其与血清总胆红素浓度峰值的相关性。方法对100名严重高胆红素血症新生儿(研究组)和30名正常新生儿(对照组)进行畸变产物耳声发射(DPOAE)、听性脑干反应(ABR)和1 000 Hz探测音声导抗检查,于3月龄和6月龄时对研究组进行复查。比较两组结果并分析患儿血清总胆红素浓度峰值与ABR反应阈的相关性。结果①对照组ABR、DPOAE、声导抗检查均正常;②研究组中所有患儿鼓室导抗图均为A型,15人22耳有不同程度的听力损失(ABR异常),其中6人(40%,6/15)9耳DPOAE不能引出,9人(60%,9/15)13耳DPOAE引出。3月龄复查时,15人中听力损失改善3人(4耳),加重1人(2耳),6月龄复查时与3月龄时无改变;③研究组血清总胆红素浓度峰值与ABR反应阈呈浓度依赖性正相关,血清总胆红素>500μmol/dl是高胆红素致听力损失的风险因素。结论严重新生儿高胆红素血症导致的听力损失表现为单耳或双耳感音神经性聋,部分表现为听神经病的听力学特点,3～6月龄部分听力损失可逆转,部分听力损失可继续加重。