Prevalence and etiology of unilateral sensorineural hearing impairment in a Finnish childhood population

Close the gap for routine mumps vaccination in Japan

Mumps is a vaccine-preventable disease. Because the mumps vaccine can cause aseptic meningitis in rare cases, this vaccine is not routine in Japan. This has led to low vaccine coverage and severe disease burden in Japan. The present review summarizes mumps epidemiology and vaccination and discusses effective future strategies to mitigate the current disease burden of mumps in Japan. Although a recent study reported that mumps vaccine coverage rates are improving in Japan, current coverage rates are far below the optimal rate to suppress the ongoing epidemic, which has caused an average annual financial loss of 85 billion JPY between 2000 and 2016. Recent reports have demonstrated a much lower incidence of vaccine-induced aseptic meningitis in newly developed vaccines, especially when administered at 1 year of age. Cost-effectiveness studies suggest that routinization of the currently distributed domestic vaccine would be highly cost-effective. In addition, questionnaire surveillance data suggest that the majority of the Japanese population accepts the nominal risk of the vaccine when the proper information is provided. Finally, there are some successful programs in Japan that have attained high vaccine coverage rates with financial support from local governments. Taken together, these data suggest that the mumps vaccine should be immediately included in routine vaccines in Japan.

An Investigation of Hearing (250-20,000 Hz) in Children with Endocrine Diseases and Evaluation of Tinnitus and Vertigo Symptoms

Introduction  Despite much advancement in medicine, endocrine and metabolic diseases remain an important cause of morbidity and even mortality in children.

Objective  The present study was planned to investigate the evaluation of hearing that also includes high frequencies, and the presence and degree of vertigo and tinnitus symptoms in pediatric patients diagnosed with endocrine diseases such as type 1 diabetes mellitus (DM), growth hormone deficiency (GHD), obesity, idiopathic short stature, and precocious puberty

Methods  The present study included a patient group of 207 children patients diagnosed with endocrine disease (95 males, 112 females; mean age 9.71 years old [range 6–16 years old]) and a control group including 55 healthy children who do not have any kind of chronic disease (26 males, 29 females; mean age 9.33 years old [range 6–16 years old]). The subjects underwent a hearing test with frequencies between 250 and 20,000 Hz. The vestibular and tinnitus symptoms were evaluated with the Pediatric Vestibular Symptom Questionnaire.

Results  Out of 207 patients in the patient group, 5 (2.4%) had hearing loss in pure tones, 10 (4.8%) had it in high frequencies, 40 (19.3%) had tinnitus symptoms, and 18 (8.7%) had vertigo symptoms. A total of 4 out of 207 patients in the study group (1.9%), 2 out of 59 with type 1 DM patients (3.4%), 1 out of 46 with GHD (2.2%), and 1 out of 43 obesity patients (2.3%) had hearing loss, vertigo, and tinnitus symptoms.

Conclusions  Our results suggest that some childhood endocrine diseases can cause some changes in the inner ear, although the exact cause is unknown. Perhaps, a detailed hearing and balance examination should be a routine in a child diagnosed with an endocrine disease. We think it is necessary to work on more comprehensive patient groups and tests in the future.

The impact of permanent early-onset unilateral hearing impairment in children - A systematic review

BACKGROUND

Decision-making on treatment and (re)habilitation needs to be based on clinical expertise and scientific evidence. Research evidence for the impact of permanent unilateral hearing impairment (UHI) on children's development has been mixed and, in some of the reports, based on fairly small, heterogeneous samples. Additionally, treatment provided has been highly variable, ranging from no action taken or watchful waiting up to single-sided cochlear implantation. Published information about the effects of treatment has also been heterogeneous. Moreover, earlier reviews and meta-analyses published on the impact of UHI on children's development have generally focused on select areas of development.

OBJECTIVES

This systematic review aimed to summarize the impact of children's congenital or early onset unilateral hearing impairment on listening and auditory skills, communication, speech and language development, cognitive development, educational achievements, psycho-social development, and quality of life.

METHODS

Literature searches were performed to identify reports published from inception to February 16th, 2018 with the main electronic bibliographic databases in medicine, psychology, education, and speech and hearing sciences as the data sources. PubMed, CINALH, ERIC, LLBA, PsychINFO, and ISI Web of Science were searched for unilateral hearing impairment with its synonyms and consequences of congenital or early onset unilateral hearing impairment. Eligible were articles written in English, German, or Swedish on permanent unilateral hearing impairments that are congenital or with onset before three years of age. Hearing impairment had to be of at least a moderate degree with PTA ≥40 dB averaged over frequencies 0.5 to 2 or 0.5-4 kHz, hearing in the contralateral ear had to have PTA_{0.5-2 kHz} or PTA_{0.5-4 kHz} ≤ 20 dB, and consequences of unilateral hearing impairment needed to be reported in an unanimously defined population in at least one of the areas the review focused on. Four researchers independently screened 1618 abstracts and 566 full-text articles for evaluation of study eligibility. Eligible full-text articles were then reviewed to summarize the results and assess the quality of evidence. Additionally, data from 13 eligible case and multi-case studies, each having less than 10 participants, were extracted to summarize their results. Quality assessment of evidence was made adapting the Grades of Recommendations, Assessment, Development, and Evaluation (GRADE) process, and reporting of the results adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards.

RESULTS

Three articles with the quality of evidence graded as very-low to low, fulfilled the eligibility criteria set. Due to the heterogeneity of the articles, only a descriptive summary could be generated from the results. Unilateral hearing impairment was reported to have a negative impact on preverbal vocalization of infants and on sound localization and speech perception both in quiet and in noise.

CONCLUSIONS

No high-quality studies of consequences of early-onset UHI in children were found. Inconsistency in assessing and reporting outcomes, the relatively small number of participants, low directness of evidence, and the potential risk of confounding factors in the reviewed studies prevented any definite conclusions. Further well-designed prospective research using larger samples is warranted on this topic.

Unilateral Sensorineural Hearing Loss: Medical Context and Etiology

Objective: Unilateral sensorineural hearing loss (USNHL) is known to impact on school performance and social skills during childhood, but the etiologies remain unclear. The aim of this study was to assess various etiologies and to study the clinical contexts in this population. Methods: The study is a retrospective review. Characteristics of hearing loss (HL), audiometric parameters, imaging, and genetic and medical contexts were analyzed. Results: Eighty children were included. USNHL was profound in 68%, could be progressive in 19%, and become bilateral in 7.5% of cases. Inner ear malformations were identified in 41% of cases; cochlear nerve deficiency (CND) was frequent (33%). Cytomegalovirus (CMV) infection and genetic syndromes were confirmed in 10 and 6% of cases, respectively. Conclusion: Long-term hearing follow-up remains useful in USNHL as it can become bilateral. Looking to etiology, MRI should be the gold standard, as CND is frequently observed and screening for CMV infection should be systematic. Genetic etiologies appear to be different compared to bilateral HL. Further genetic research in this domain is needed.

Hearing Loss Progression and Contralateral Involvement in Children with Unilateral Sensorineural Hearing Loss

Objectives

We undertook this study to determine the rate of hearing loss progression in the affected ear of children with unilateral sensorineural hearing loss and without an enlarged vestibular aqueduct, and the rate of new-onset hearing loss in the contralateral ear.

Methods

We searched the database at our pediatric tertiary care center to identify patients who met the inclusion criteria, examining demographic variables, audiometric data, and presumptive causes.

Results

We identified 198 patients. At presentation, they showed slight left-sided and male predominances. Of 142 patients who had sufficient audiometric follow-up for us to evaluate progression, 21% showed ipsilateral progression and 10.6% developed new-onset hearing loss in the contralateral ear. Isolated high-frequency loss was identified in 11 patients (5.6%), 8 of whom had sufficient follow-up for us to identify progression. Two showed progression; 4 others with progression in the ipsilateral ear developed new-onset high-frequency loss in the contralateral ear. Temporal bone anomalies were identified in 26 children (13%), and these children were more likely to have profound hearing loss than were those without temporal bone anomalies (46% versus 23%).

Conclusions

The findings suggest that unilateral sensorineural hearing loss may not always be a unilateral process, but that it may be the initial manifestation of bilateral auditory dysfunction.

Association between metabolic syndrome and sensorineural hearing loss: a cross-sectional study of 11,114 participants

BACKGROUND/OBJECTIVES

Hearing loss (HL) is associated with certain diseases and affects health, resulting in a low quality of life. Some components of the metabolic syndrome (MetS) coincide with the risk factors for sensorineural hearing loss (SNHL). To date, very few studies have examined the link between MetS and HL. The aim of the current study was to try to understand the potential association between MetS and HL.

METHODS

Using Iranian health surveys of professional drivers, we enrolled 11,114 individuals aged 20-60 years, whose main job is to operate a motor vehicle. We examined participants for the presence and absence of SNHL and the components of the MetS. Additionally, we investigated the relationship between MetS and the pure tone air conduction hearing thresholds of participants with SNHL, including low-frequency and high-frequency thresholds.

RESULTS

This cross-sectional study consisted of 11,114 participants: 3202 (28.81%) diagnosed with MetS and 7911 (71.18%) without and 2772 (24.94%) with SNHL and 8432 (75.86%) without. Participants with SNHL had a higher number of components of MetS (P<0.001 for all components).

CONCLUSION

Our results demonstrated that an association possibly exists between different components of MetS (obesity, hypertension, hypertriglyceridemia, high fasting glucose levels, and waist circumference) and SNHL in a population of West Azerbaijan drivers. Therefore, it is important to schedule periodic checkups for drivers to detect and avoid the increase in MetS components at an early stage in this population.

Computed tomography demonstrates abnormalities of contralateral ear in subjects with unilateral sensorineural hearing loss

PURPOSE

Prior studies have associated gross inner ear abnormalities with pediatric sensorineural hearing loss (SNHL) using computed tomography (CT). No studies to date have specifically investigated morphologic inner ear abnormalities involving the contralateral unaffected ear in patients with unilateral SNHL. The purpose of this study is to evaluate contralateral inner ear structures of subjects with unilateral SNHL but no grossly abnormal findings on CT.

MATERIALS AND METHODS

IRB-approved retrospective analysis of pediatric temporal bone CT scans. 97 temporal bone CT scans, previously interpreted as "normal" based upon previously accepted guidelines by board certified neuroradiologists, were assessed using 12 measurements of the semicircular canals, cochlea and vestibule. The control-group consisted of 72 "normal" temporal bone CTs with underlying SNHL in the subject excluded. The study-group consisted of 25 normal-hearing contralateral temporal bones in subjects with unilateral SNHL. Multivariate analysis of covariance (MANCOVA) was then conducted to evaluate for differences between the study and control group.

RESULTS

Cochlea basal turn lumen width was significantly greater in magnitude and central lucency of the lateral semicircular canal bony island was significantly lower in density for audiometrically normal ears of subjects with unilateral SNHL compared to controls.

CONCLUSION

Abnormalities of the inner ear were present in the contralateral audiometrically normal ears of subjects with unilateral SNHL. These data suggest that patients with unilateral SNHL may have a more pervasive disease process that results in abnormalities of both ears. The findings of a cochlea basal turn lumen width disparity >5% from "normal" and/or a lateral semicircular canal bony island central lucency disparity of >5% from "normal" may indicate inherent risk to the contralateral unaffected ear in pediatric patients with unilateral sensorineural hearing loss.

Ocorrência de perda auditiva unilateral em pacientes com fissura labiopalatina

OBJETIVO: investigar a ocorrência da perda auditiva unilateral em indivíduos com fissura labiopaltina. MÉTODOS: estudo retrospectivo com 500 prontuários de pacientes com fissura labiopalatina. RESULTADOS: foram levantados 55 sujeitos com perda auditiva unilateral, 27(49,1%) do gênero masculino e, 28 (50,9%) do gênero feminino, com média de idade de 14,6 anos. Dezoito (32,73%) apresentaram perda auditiva na orelha direita e 37(67,27%) na orelha esquerda, 72,73% (40 sujeitos) com perda auditiva do tipo condutiva, 18,18% (10 sujeitos) do tipo neurossensorial e 9,09% (5 sujeitos) do tipo mista. Quanto ao grau da perda auditiva foi constatada maior ocorrência de perda auditiva de grau leve. CONCLUSÃO: a perda auditiva unilateral foi mais frequente nos indivíduos com faixa etária de 0 a 11 anos, com igual proporção em gênero. A perda auditiva unilateral pode comprometer aspectos sociais e emocionais do sujeito, levando-o a necessitar de uma intervenção apropriada.

Temporal bone high-resolution computed tomography in non-syndromic unilateral hearing loss in children

OBJECTIVE

The aim of this study was to disclose possible inner ear abnormalities/pathologies by means of high-resolution computed tomography (HRCT) of the temporal bone (TBHRCT) in children with unilateral hearing loss (UHL).

METHODS

Retrospective review of audiological evaluation and TBHRCT in 22 children with UHL.

RESULTS

Two thirds of the children showed profound hearing loss. Review of HRCT scans identified inner ear malformations/pathologies in 9 (41%) cases and a high jugular bulb (HJB), always dehiscent with the vestibular aqueduct, in another 5 (22%). Inner ear malformations included enlarged vestibular aqueduct, common cavity and cochleovestibular hypoplasia, while labyrinthine ossification was the detected pathology. In 1 child, the common cavity of the right ear was associated with congenital melanocytic naevus of the left eyelid and lipomeningocele. To the best of our knowledge, this condition has never been described.

CONCLUSIONS

The aetiology of UHL may be revealed in more than half of patients by means of TBHRCT. Besides common inner ear abnormalities, TBHRCT should be evaluated carefully to rule out HJB, dehiscences, diverticulum or erosion of inner ear structures.

The role of dyslipidemia in sensorineural hearing loss in children

OBJECTIVE

The relationship between dyslipidemia and hearing is controversial; especially in children, the available evidences are scarce. This study is designed to determine whether dyslipidemia is associated with sensorineural hearing loss in a group of 5-18-year-old children and adolescents.

METHODS

Through an analytic cross-sectional study, records of all 5-18-year-old children who attended the pediatric endocrinology clinic of Loghman Hospital in Tehran, Iran, between April 2007 and April 2009 were reviewed. Records with a lipid profile were determined. Lipid profiles were repeated for eligible cases; they were enrolled if the results were the same as before (normal or dyslipidemic). Hearing loss, speech discrimination scores and lipid profiles were analyzed.

RESULTS

When controlled for age and sex, no association between dyslipidemia and sensorineural hearing loss were found. There was also no statistically significant relationship between dyslipidemia and sensorineural hearing loss in different age groups.

CONCLUSIONS

Dyslipidemia seems to have no association with sensorineural hearing loss in 5-18 years old children according to this study.

Mumps

Mumps is a common childhood infection caused by the mumps virus. The hallmark of infection is swelling of the parotid gland. Aseptic meningitis and encephalitis are common complications of mumps together with orchitis and oophoritis, which can arise in adult men and women, respectively; other complications include deafness and pancreatitis. Clinical diagnosis can be based on the classic parotid swelling; however, this feature is not present in all cases of mumps and can also occur in various other disorders. Laboratory diagnosis is based on isolation of virus, detection of viral nucleic acid, or serological confirmation (generally presence of IgM mumps antibodies). Mumps is vaccine-preventable, and one dose of mumps vaccine is about 80% effective against the disease. Routine vaccination has proven highly effective in reducing the incidence of mumps, and is presently used by most developed countries; however, there have been outbreaks of disease in vaccinated populations. In 2005, a large epidemic peaked in the UK, and in 2006 the American midwest had several outbreaks. In both countries, the largest proportion of cases was in young adults. In the UK, susceptible cohorts too old to have been vaccinated and too young to have been exposed to natural infections were the primary cause of the mumps epidemic. In the USA, effectiveness and uptake in combination appear not to have been sufficient to obtain herd immunity for mumps in populations such as college students.

Causation of permanent unilateral and mild bilateral hearing loss in children

Children with permanent unilateral or mild bilateral hearing loss have been a focus of concern by audiologists, educators, and physicians for at least 2 decades. These children are known to be at risk for psychoeducational difficulties. However, despite this concern, little has been learned about the causative factors of these hearing losses and how those factors might be contributing to child development. This review of known causes of permanent unilateral and mild bilateral hearing loss in children is meant to draw attention to the importance of the search for etiologic factors. That is, the identification of the hearing loss should not signal the end of the diagnostic process but, rather, the beginning of a search for causation. With the combined efforts of audiologists, otolaryngologists, pediatricians, geneticists, and other medical professionals, we may enhance our understanding of the primary causes of unilateral and mild bilateral hearing loss and, perhaps, create links between causative factors and psychosocial and psychoeducational outcomes.

A case of unilateral sensorineural hearing loss caused by a venous malformation of the internal auditory canal

Intracranial vascular malformations can be classified as telangiectasis, varices, cavernous malformations, venous malformations (VMs), or arteriovenous malformations. VMs are congenital vascular malformations of the brain thought to be anomalies of the normal venous drainage. VMs are the most common intracranial vascular malformations documented by brain imaging and by autopsy series. However, vascular lesions of the internal auditory canal (IAC) are extremely rare. We report here a case of a VM arising within the IAC and expanding to the brainstem, causing a unilateral profound sensorineural hearing loss (SNHL). To the best of our knowledge, this is the first documented case of a VM as a rare cause of a unilateral SNHL in a child.

Unilateral Hearing Impairment in Oman: A Community-Based Cross-Sectional Study

This report on unilateral hearing loss is based on the findings of a national survey on hearing loss and blindness in Oman. The survey of randomly selected households was conducted by trained healthcare personnel between Oct. 1, 1996, and Feb. 28, 1997. A total of 11,402 subjects of all ages were screened for hearing loss. Those who reported hearing impairment in either ear were subsequently reexamined by otologists in hospitals to confirm the findings and to determine the cause of the hearing loss. Based on these findings, we calculated that the prevalence of unilateral hearing impairment throughout Oman was 30.06 per 1,000 population (95% confidence interval [CI]: 29.80 to 30.31). Males had a significantly higher rate (36.67/1,000 [95% CI: 34.55 to 38.79]) than females (23.88/1,000 [95% CI: 21.82 to 25.94]). The causes of unilateral hearing loss were different from the reported causes of bilateral hearing loss. Impacted earwax (16.0% of cases) and otitis media with effusion (13.1%) were the most common identifiable causes of unilateral hearing loss; genetic causes were responsible for less than 2% of cases. Just over one-half of the hearing-impaired patients had only a mild hearing loss. Impairment rates varied in different regions of the country.

Parental awareness of hearing impairment in their school-going children and healthcare seeking behaviour in Kisumu district, Kenya

BACKGROUND

Hearing-impaired children who are identified early and appropriately managed have improved outcomes in speech, language, cognitive and social development. Enhanced parental awareness of their child's hearing disability, behavioral, developmental and psychosocial limitations is essential to sustaining timely detection and appropriate intervention. Additionally, availability of services for diagnosis, treatment and habilitation would improve the demand for pedaudiological care in this community.

OBJECTIVE

To describe level of parental awareness of childhood HI and the pattern of access to and utilization of ambulatory care services.

SUBJECTS

Thirty-three parents of lower primary school-going children who failed audiometric screening from sampled schools in Kisumu district, western Kenya.

MAIN OUTCOME MEASURES

First person to detect HI, age of child at first suspicion of HI, source of ambulatory health care and use of the health care facilities.

RESULTS

The prevalence of HI was 2.48%. Most parents/guardians (69.7%) were aware of their child's hearing impairment. Of these, 63.6% were first to detect HI in the pupils, while 30.3% were detected by screen. Most children (57.2%) were first recognized with (HI) after age 2 years. The mean age at identification was 5.5 years. The median travel distance to the preferred health care facility was 2 km (IQR 1-2.5). Parents seldom sought or lacked help for their hearing-impaired children. Of 27.3% who asked for hearing assessment, 9.1% received some counsel on HI and 12.1% received medication, one (3%) was referred for audiological assessment and none used a hearing aid. Use of health facilities for maternal care was (65.7%) and immunization (62.9%).

CONCLUSIONS

Despite adequate parental awareness of chronic childhood disability, health facilities were underutilized. This indicates the need to further stimulate and maintain a desirable level of uptake of services for diagnosis, treatment and habilitation of childhood HI, while sustaining delivery of effective and acceptable high quality paediatric care.

Idiopathic sudden sensorineural hearing loss in children

OBJECTIVE

Although idiopathic sudden sensorineural hearing loss (ISSHL) is a frequent disease in adults, less is known about incidence and treatment of ISSHL in children.

METHOD

A retrospective chart analysis was performed to evaluate the frequency of ISSHL in children aged under 18 years between 2000 and 2003, who were treated in our department. Children received prednisolone intravenously at an initial dose of 3mg/kg bodyweight. Prednisolone dose was reduced to half every second day. The medication was given for a maximum of 14 days or finished 2 days after the hearing normalized in pure-tone audiometry. The follow-up was continued between 3 and 14 months.

RESULTS

The complete recovery rate was 57%, and the partial recovery was 36%. Initial hearing loss of 50dB and more was predictive for poor outcome in children (p=0.028). Presence of tinnitus was without relevance for the outcome. The incidence of ISSHL in the local area of about 250,000 inhabitants was 1/10,000 in children.

CONCLUSION

ISSHL seems to be a less frequent disease in children than in adults. Severe initial hearing loss is coupled with poor outcome. Under treatment with prednisolone hearing improvement was found in 13 of 14 patients.

Birth weight and hearing impairment in norwegians born from 1967 to 1993

OBJECTIVES

To estimate the association between birth weight and hearing impairment among Norwegians born between 1967 and 1993, taking other pregnancy-related conditions into consideration.

METHODS

A cohort study was conducted of all Norwegian live births from 1967 to 1993 (n = 1 548 429) linking information of the Medical Birth Registry of Norway and the register for the National Insurance Administration, which covers all Norwegians. The Medical Birth Registry of Norway has recorded information on birth weight and other pregnancy-related conditions as well as diseases of the mother before and during pregnancy. The register of the National Insurance Administration contains information on all Norwegians who have received cash benefits for a disease/disability, including hearing impairment. Data up to 1997 are included; thus, the follow-up period varies between 29 and 3 years.

RESULTS

The occurrence of hearing impairment was 11 per 10 000, decreasing from 60 per 10 000 for birth weights <1500 g to 6 per 10 000 for birth weights >4499 g. Compared with birth weights between 3000 g and 3499 g, the adjusted rate ratio of hearing impairment was 7.55 (95% confidence interval: 4.81-11.87) for birth weights <1500 g and 0.50 (95% confidence interval: 0.34-0.73) for birth weights >4499 g. The association did not change substantially with adjustment for other pregnancy-related conditions. Restricting the analyses to term born, the association between hearing impairment and low birth weight became stronger.

CONCLUSIONS

Birth weight was a strong predictor of hearing impairment in the Norwegian population. Children who were born at term with a low birth weight seemed to be a particularly vulnerable group.

Unilateral sensorineural hearing impairment in childhood: analysis of 31 consecutive cases

This report presents the selected variables of a consecutive series of 1-10-year-old children with unilateral sensorineural hearing impairment (USNHI; defined as four-frequency pure-tone audiometry (PTA) 0.5, 1, 2, 4 kHz > or = 30 dB HL): severity, presumptive aetiologies, age at ascertainment, hearing aid acceptance, non-verbal intelligence, time of occurrence of first words and two-word utterances, size of vocabulary, and linguistic achievements. During a 4-year-period in a defined geographical area of Germany (Lower Saxony), 31 children were carefully audiologically and psychologically examined at the Department of Phoniatrics/Pedaudiology, University of Göttingen. All children were fitted unilaterally with a hearing aid. The HI was mild in 3%, moderate in 23%, severe in 29% and profound in 45% of the cases. The hearing defect was congenital in 23%, postnatally acquired in 16%, and of unknown onset in 61% of the cases. The affected side was the right in 17 cases, and the left in 14. The mean age at ascertainment was 65.5 months (SD 25.5; median 70). According to parental judgement, nearly 81% of the children had accepted their hearing aid (based on the daily/weekly time for which the child was using the hearing aid). On average, the children scored in the normal range in standardized non-verbal intelligence tests. They were delayed in using two-word phrases (on average for 5 months), but not in using their first words. However, children with USNHI experienced no more difficulty on standardized linguistic tasks than normally hearing subjects of the same age and gender.

Audiological assessment of unilateral deafness

Unilateral deafness constitute medical (aetiological diagnosis, treatment, hearing aid fitting) and social problems (no certification of disability). Following audiological examinations were performed in the study: pure tone audiometry (PTA), impedance audiometry, auditory brainstem responses (ABR), otoacoustic emissions (OAE), as well as balance, taste, examinations and electric sensitivity of the acoustic nerve. In cases of tinnitus the parameters of its character were done. All of our patients underwent X-ray investigations, i.e. ear X-ray by Schüller and Stenvers methods, computerized tomography or magnetic resonance imaging. In some cases phoniatric and logopaedic examinations were performed. For aetiological diagnosis electrophoresis and immunological test (IgG and IgM against mumps) were carried out. The results were presented in two groups of patients with sudden and those of long lasting progressive unilateral deafness. Some of the patients were pharmacologically treated before the evaluation. It is concluded that the statistic analysis could be a basis for the management and prognosis of the unilateral deafness.

Otoacoustic emissions and auditory assessment in infants at risk for early brain damage

The importance of early hearing screening has long been recognized, as the prognosis for the hearing impaired child is improved when the diagnosis is made as early as possible, and the intervention is begun immediately. For clinical screening of hearing impairment, the recording of otoacoustic emissions was recommended. As some risk factors for early brain damage are at the same time also risk factors for dysfunction of auditory system, we presumed that infants at risk for brain damage have hearing impairment more frequently than the rest of the population of the same age. We were interested in the role of otoacoustic emission testing during the assessment of auditory function in these infants. There were 110 infants at risk for brain damage included in the study. After thorough otorhinolaryngological examination, auditory function was estimated by recording of otoacoustic emissions, tympanometry, pure tone audiometry and, when necessary, auditory brainstem responses. Otoacoustic emissions were recorded by Madsen-Electronics Celesta 503 in an acoustically treated sound room. We registered spontaneous as well as transient and distortion product otoacoustic emissions. The neurologist formed two groups with different degrees of neurological risk. The collected results of auditory function were compared with the degree of neurological risk. For the statistical analysis, the procedure chi(2) and Fischer test were used. Spontaneous otoacoustic emission was detected in 38.2% of examinees. Evoked otoacoustic emissions were registered in 87.3% of infants. The testing had to be repeated in 32.7% of infants. We observed evoked otoacoustic emissions to be present also in a child with sensorineural hearing impairment and no auditory brainstem responses. Up to 32.7% of infants at risk for brain damage were hard of hearing. Conductive hearing loss was discovered with 25.4% of infants, and eight (7.3%) had sensorineural hearing impairment. In the group of examinees with only risk factors 3.6% had sensorineural impairment and in a group with abnormal motor development, there were 18.5% with that kind of hearing loss. Fischer test confirmed a statistically significant difference between the groups. Infants at risk for brain damage have more frequently impaired auditory function than their peers. For this reason, it is especially important to focus attention on the hearing condition when dealing with this population. Recording of evoked otoacoustic emissions is very helpful in pediatric audiometry, but any interpretation of the results should consider the possibility of auditory neuropathy.