Findings from multidisciplinary evaluation of children with permanent hearing loss

Objectives

To describe clinical findings from a multidisciplinary program for children with permanent hearing loss (PHL).

Methods

Retrospective chart review at a tertiary care children's hospital. Patients: Two hundred patients charts were selected from the population of 260 children with permanent hearing loss presenting between July 2005 and December 2006. Main outcome measures: PHL etiology; radiographic findings; clinical findings by genetics, ophthalmology, developmental pediatrics, speech pathology, and aural rehabilitation.

Results

Etiology of hearing loss was determined in 60% of subjects. Genetic causes of hearing loss were identified or presumed (positive history of first degree relative with hearing loss) in 27% of the children. Structural ear anomalies were found in 20% of children. Among the 36% of children with CNS imaging, abnormal findings were noted in 32%. There were a high rate of ophthalmological findings (53%) among children seen by ophthalmology (n = 105). Neurodevelopmental evaluations were completed in 58% of subjects and clinically significant findings were noted in 68%. Of the 61% of children who receiving received speech/language evaluations, 77% required intervention. Over half of the 40% of subjects who had an aural rehabilitation evaluation needed therapy. There were not significant differences in rates of findings for children with mild or unilateral hearing loss as compared to children with more severe degrees of hearing loss.

Conclusions

Interdisciplinary medical evaluation of children with PHL allows for the identification and treatment of clinically significant ophthalmologic, neurodevelopmental, genetic, and speech/language disorders. A high rate of CNS and temporal bone abnormalities were identified. These findings provide an understanding of the importance of considering thorough medical and developmental evaluations among children who are deaf/hard of hearing.     

Prevalence of GJB6 mutations in Chinese patients with non-syndromic hearing loss

Objective

To investigate the distribution of GJB6 mutations in Central Chinese population with non-syndromic hearing loss.

Method

Totally 655 hearing impaired patients in Hubei province of China were screened for del(GJB6-D13S1830) deletions by using multiplex PCR and sequencing of GJB6 whole coding region.

Result

The del(GJB6-D13S1830) and other mutations in GJB6 gene were not observed in our study cohort.

Conclusion

The results suggest that GJB6 mutations is not a common cause among Central Chinese population and screening for the mutations of GJB6 can be ranked as unconventional deaf gene test for this population.     

Development of canal cholesteatoma in a patient with prenatal isotretinoin exposure

Purpose

To describe the clinical and radiologic findings in a case of isotretinoin embryopathy-like syndrome and discuss management of hearing loss, congenital external auditory canal (EAC) stenosis, and EAC cholesteatoma.

Methods

Review of medical, audiological, and radiological records.

Results

An 8 year old female presented with bilateral moderate conductive hearing loss, bilateral microtia, left EAC stenosis, and right EAC atresia, secondary to prenatal isotretinoin exposure. Comorbidities included developmental delay, ventricular septal defect, hypotonia, and retinal maldevelopment. The left EAC was sharply upsloping with a 2 mm-diameter meatus. Computed tomography (CT) scan of the temporal bone demonstrated normal middle and inner ears bilaterally; serial CT scans over 6 years demonstrated progressive development of left canal cholesteatoma. Implantation of a right BAHA system was performed, followed by left canalplasty and excision of cholesteatoma with facial nerve monitoring. An endaural incision was utilized to avoid compromising future microtia repair. Postoperative left-sided hearing improved to mild low-frequency conductive hearing loss rising to normal at 2000 Hz and above.

Conclusions

Despite extensive precautions for its use, isotretinoin remains a cause of major birth defects, including sensorineural, conductive or mixed hearing loss. Congenital EAC stenosis is much less common than congenital atresia or acquired stenosis; optimal surgical approaches vary depending on hearing status and facial nerve anatomy. Close monitoring for development of canal cholesteatoma is necessary.     

Universal newborn hearing screening in the Champagne-Ardenne region: A 4-year follow-up after early diagnosis of hearing impairment

Introduction

Permanent congenital hearing loss is one of the most frequent congenital anomaly at birth. Universal newborn hearing screening (UNHS) was introduced in numerous countries in order to allow an early diagnosis and intervention for congenital hearing impairment.

Objective

First aim of this study is to evaluate the accuracy of early diagnosis of hearing impairment after UNHS. Second aim is to discuss the auditory intervention proposed after this diagnosis. Last aim is to evaluate the relevance of UNHS for early diagnosis and intervention.

Materials and methods

Prospective study. UNHS program was introduced in the entire French region of Champagne-Ardenne in January 2004. Forty-one children have benefited of an early diagnosis of hearing impairment until June 2007. They were included in an intervention program consisting of an audiometric follow-up and an auditory intervention. This program was conducted until June 2008.

Results

There were 28 males patients and 13 females patients. The diagnosis of hearing aid impairment was carried at an average age of 3.2-month. The auditory follow-up allowed confirming the initial diagnosis of deafness for the majority of the children as for their degree of hearing loss. Auditory intervention was heterogeneous depending on degree of hearing loss of the children.

Conclusion

This UNHS program demonstrates its validity and feasibility for early diagnosis and intervention of congenital hearing impairment. It brought a major impact on the management of congenital hearing impairment in Champagne-Ardenne.     

Association of otoscopic findings and hearing level in pediatric patients with otitis media with effusion

Objective

To find the association between the abnormalities of tympanic membrane characteristics and the hearing level in pediatric patients with otitis media with effusion.

Methods

Sixty-three pediatric patients with otitis media with effusion had undergone ear examinations by pneumatic otoscopy to assess the color, transparency, mobility, fluid level and retraction of the tympanic membrane. An audiogram was done in the same setting, average hearing threshold and air-bone gap were measured. Otoscopic findings and the result of the hearing test were analyzed to identify the association between the abnormalities of the tympanic membrane characteristics and elevated hearing threshold.

Results

Hearing loss was found in 92.1% of the patients. Mean hearing level was 31.7 ± 10.3 dB. From linear regression analysis, the patients with dull or opaque tympanic membrane had a significantly higher hearing threshold of 7.2 dB than the patient with translucent ear drum after adjusting for mobility and retraction. The patients with tympanic membrane retraction had a higher hearing threshold of 5.1 dB than the patient who had no retraction after adjusting for transparency and mobility. Mobility had a significant relationship to elevated hearing threshold in the univariate analysis but not in multivariable analysis.

Conclusion

Opacity and retraction were the two characteristics of abnormal tympanic membrane that were associated with elevated hearing threshold in the patients with otitis media with effusion. Hearing test is suggested if opacity or retraction of the tympanic membrane is found.     

Auditory evoked magnetic fields in children with functional hearing loss

Objectives

Abnormal cortical responses in patients with functional hearing loss were evaluated by magnetoencephalography, which can better separate bihemispherical activity than electroencephalography.

Methods

Auditory evoked fields in response to 1 kHz or 2 kHz tone bursts at 80 dB sound pressure level were measured by a helmet-shaped magnetoencephalography system in 22 patients with functional hearing loss (18 females, mean age 13.2 years) as well as 5 control subjects under 10 years old. Waveform, latency, and equivalent current dipole of N100m responses were used to evaluate activity in the bilateral auditory cortices.

Results

Abnormal N100m of the contralateral response to the stimulated ear, either absence or delayed latency in comparison to normal adult subjects, was found in 6 of the 7 patients with functional hearing loss aged 9 years or younger, but in only 3 of the 15 patients aged 10 years or older. However, such abnormalities were also observed in younger control subjects.

Conclusion

Auditory evoked field may be applied to objectively evaluate cortical auditory function in patients with functional hearing loss, but the normal findings for young children have not yet been established.     

Newborn hearing screening on infants at risk

Objectives

This article presents the results of newborn hearing screenings on infants at risk of hearing impairment at the French University Hospital of Besançon from 2001 to 2007.

Materials and methods

All newborns at risk of hearing impairment were tested according to the method recommended by the Joint Committee on Infant Hearing (JCIH): a two-step automated oto-acoustic emissions (AOAE) program, completed by an auditory brainstem response (ABR) for the positive diagnosis of hearing impairment. The screening started with AOAE on the third day of life, at the earliest. If one or both ears did not have AOAE, the infant was re-tested at which time, should the AOAE again be positive, ABR was performed. When the ABR threshold was 40 dB or more, the infant was referred to an audiologist specialized in infant deafness for diagnosis confirmation and management.

Results

Over the period, 1461 infants were screened, among whom 4.55% were diagnosed as deaf or hard of hearing. Nearly 10% of the infants were lost to follow up. Forty-six children had a sensorineural hearing impairment, of which 34 were bilateral and were managed before the age of 6 months. The risk factors for sensorineural hearing loss were (in order of statistical significance): severe birth asphyxia; neurological disorder; syndromes known to be associated with hearing loss; TORCH (toxoplasmosis, rubella, cytomegalovirus, herpes) infections; family history of deafness; age at the time of screening; and the association of 2 or more risk factors. However, birth weight inferior to 1500 g and premature birth before the 34th week of pregnancy did not show a statistically significant influence on sensorineural hearing loss. Craniofacial anomalies (mostly cleft palate and ear aplasia) were a significant factor for conductive hearing loss.

Conclusion

Our selected hearing screening on infants at risk allowed 60 deaf children access to early management. However, too many children were lost to follow up; which revealed that better information regarding risk of hearing loss must be provided to parents and paramedics and universal newborn screening needs to be performed. The most important result of this study is that in a population of hearing impaired children, with an impairment incidence close to what is commonly reported, the association of several risk factors proves to be a significant additional risk factor for hearing impairment.     

Etiological diagnosis in the hearing impaired newborn: proposal of a flow chart

Objective

Most industrialized countries have introduced some form of universal newborn hearing screening program. Both identification and rehabilitation of hearing loss in newborns have evolved to an acceptable standard and the need for a standardized etiological protocol is emerging.

Methods

Extensive literature search to determine which investigations can help identifying the cause of congenital hearing loss and how to limit extensive testing in these children by taking into account the most prevalent causes.

Findings

A stepwise approach to detect the cause of hearing loss in children with congenital sensorineural hearing loss was developed.

Conclusion

In general it is advised to first rule out Cx26/Cx30 and infectious causes (cytomegalovirus and, if indicated, toxoplasmosis and rubella), and to preserve more extensive investigations for those children in whom these causes do not explain the hearing loss.     

The relativity of integrity testing by telemetry in the diagnosis of cochlear implant defect: A case study and literature review

Objective

This paper report a rare case that showed the limitation of integrity testing by telemetry in detecting the cause of cochlear implant defect.

Method

We are reporting the case of a 45-year-old female who received a cochlear implant 10 years ago, owing to a profound bilateral sensorineural hearing loss. Following the cochlear implant the patient's speech discrimination threshold improved dramatically.In March 2009, after a car accident, the patient was unable to hear. The clinical and radiological examination revealed no abnormality, nor did the telemetry test, with normal implant function and normal NRT. The proceeding medical treatment with a corticosteroid therapy and hearing rehabilitation brought no improvement. Thus we decided to revise both implantations.

Result

The cochlear reimplantation was postoperatively found to have brought a marked improvement in the hearing and speech discrimination threshold. Conclusively we chose to perform a second cochlear reimplantation on the opposite side which after surgery revealed the same postoperative result.

Conclusion

The telemetry test does not always enable one to discover the cause of the cochlear implant failure.     

The audiological characteristics of a hereditary Y-linked hearing loss in a Chinese ethnic Tujia pedigree

Objective

To investigate audiometric characteristics of hearing loss in a large Chinese ethnic Tujia family and determine its hereditary type.

Methods

Total 76 live individuals were investigated in the notable 84 members of this family. The detailed audiometric evaluations were undertaken for the proband and his 47 family members. The degrees of sensorineural hearing impairment were defined as an air/bone gap <15 dB hearing loss averaged over 0.5, 1 and 2 kHz. The severity of hearing loss was established based on the hearing ability of the better ear, averaged over 0.5, 1, 2 and 4 kHz, and classified into four categories: mild, moderate, severe and profound.

Results

Nineteen patrilineal relatives of the 76 live members had hearing impairment. The age of onset ranged from 7 to 21 years old with the average of 13.2 years. The audiometric defect was described by auditory curves of a high frequency in 47% of the patients. Affected members in this family demonstrated a non-syndromic, late onset, bilateral, symmetrical, postlingual and sensorineural hearing loss.

Conclusions

The audiometric configuration in males of the pedigree is consistent with the hereditary Y-linked hearing loss. Thus we speculate that a putative gene on the Y chromosome could contribute to the cause of the disease.     

Screening for delayed-onset hearing loss in preschool children who previously passed the newborn hearing screening

Objective

The goal of this study was to investigate the prevalence of delayed-onset hearing loss in preschool children who previously passed newborn hearing screening in Shanghai, China.

Methods

Between October 2009 and September 2010, 21,427 preschool children were enrolled from five areas of Shanghai, who had passed newborn hearing screening. Children were screened for delayed-onset hearing loss with pediatric audiometers. Children with positive results in initial and re-screening tests were assessed audiologically and for risk indicators according to the Year 2007 Statement of the American Joint Committee on Infant Hearing (JCIH).

Results

During the study period, 445 children (2.08%) were referred for audiologic assessment; 16 (0.75/1000, 95% CI 0.38-1.12) had permanent delayed-onset hearing loss. Of these, five (0.23/1000) had bilateral moderate hearing loss; seven (0.33/1000) had mild bilateral hearing loss; and four (0.19/1000) had unilateral moderate or mild hearing loss. JCIH risk indicators were established for six children (6/16, 37.5%), including parental concern regarding speech and language developmental delay, neonatal intensive care unit with assisted ventilation or hyperbilirubinemia, recurrent otitis media with effusion, craniofacial malformation, and family history (n = 1 for each). The remaining ten (62.5%) had no related risk factors.

Conclusions

A significant proportion of preschool children have undiagnosed delayed-onset hearing loss. Hearing screening in preschool is recommended for an early detection.     

UK and Ireland experience of cochlear implants in children with Down Syndrome

Objectives

Down Syndrome (DS) is associated with a high incidence of hearing loss. The majority of hearing loss is conductive, but between 4 and 20% is sensorineural, which in the main is mild or moderate and is managed with conventional behind-the-ear hearing aids. Cochlear implantation is an elective invasive procedure, performed to provide some form of hearing rehabilitation in individuals with severe to profound sensorineural hearing loss, and initially candidacy criteria were strict—excluding patients with additional disabilities. With good results and expanding experience, more candidates with additional disabilities are now being implanted. A survey of UK and Ireland Cochlear Implant Programmes sought to identify the number of individuals with DS who have been implanted with a cochlear implant (CI) and to provide relevant information on outcomes of implantation in these individuals.

Methods

E-mail survey of all programmes within the British Cochlear Implant Group (BCIG). Postal questionnaire to programmes identified to have implanted a child with Down Syndrome, with data collection on pre-operative assessment, surgical and post-operative outcomes. Case series review.

Results

Three of 23 BCIG programmes have implanted a child with Down Syndrome. Four children have received implants. No intraoperative or post-operative surgical complications were encountered. All children had middle ear disease, but no problems with implantation were associated with their middle ear condition. All children remain implant users, 12 months to 4 years post-implantation.

Conclusion

Cochlear implantation is an option for a child with Down Syndrome and associated severe to profound sensorineural hearing loss. Clinicians caring for these children and their families should consider referral for assessment by a Cochlear Implant Programme.     

Prevalence of the c.35delG and p.W24X mutations in the GJB2 gene in patients with nonsyndromic hearing loss from North-West Romania

Objective

In Central and South-Eastern European countries, the most frequent mutation types responsible for congenital nonsyndromic sensorineural hearing loss (NSHL) are c.35delG and p.W24X (15-55.8% and 2.5-4.3%, respectively). The aim of the study was to determine for the first time in Romania the prevalence of c.35delG and p.W24X mutations in patients with NSHL.

Material

75 unrelated children with NSHL from Transylvania (North-West Romania).

Methods

a. Audiological examination (otoscopy, tympanogram, acoustic otoemission and tonal audiogram or auditory evoked potentials); b. detection of the c.35delG (semi-nested-PCR, RFLP and ARMS-PCR analysis) and p.W24X (ARMS-PCR analysis) mutations.

Results

Audiological examination allowed the diagnosis of hearing loss of various degrees: moderate in 8 patients (10.7%), severe in 14 cases (18.7%), profound in 53 patients (70.6%). The number of reported mutation cases as against the number of alleles indicates a 33.3% frequency rate for c.35delG mutation and respectively 5.3% for p.W24X mutation. All 22 patients with 35delG/c.35delG genotype (19 patients), c.35delG/p.W24X genotype (2 patients) or p.W24X/p.W24X genotype (1 patient) presented profound/severe hearing loss.

Conclusion

Our study confirms that the frequency rate of the two mutations analyzed in patients with NSHL from North-West Romania is comparable to that seen in other Central and South-Eastern European countries. The homozygote or compound heterozygote states represent a major risk factor for profound or severe deafness. Audiological screening in newborns and genetic testing in confirmed congenital hypoacusis cases are compulsory for early therapeutic intervention (hearing prosthesis or cochlear implant) and genetic counselling.     

Absence of GJB6 mutations in Indian patients with non-syndromic hearing loss

Objective

Hearing loss is the most frequent sensory defect in human being. Genetic factors account for at least half of all cases of profound congenital deafness. The 13q11-q12 region contains the GJB2 and GJB6 genes, which code connexin 26 (CX26) and connexin 30 (CX30) proteins, respectively. Mutations in the gene GJB2, encoding the gap junction protein connexin 26, are considered to be responsible for up to 50% of familial cases of autosomal recessive non-syndromic hearing loss and for up to 15-30% of the sporadic cases. It has also been reported that mutations in the GJB6 gene contribute to autosomal recessive and autosomal dominant hearing defects in many populations. The 342-kb deletion [del(GJB6-D13S1830)] of the Cx30 gene is the second most common connexin mutation after the CX26 mutations in some NSHL populations. The aim of this study was to screen GJB6 gene mutations in Asian Indian patients with autosomal non-syndromic hearing loss.

Methods

We screened 203 non-syndromic hearing loss patients, who were negative for homozygous mutations in GJB2 gene, for GJB6-D13S1830 deletion and mutations in coding regions of GJB6 using polymerase chain reaction, denaturing high performance liquid chromatography and direct sequencing.

Results

No deleterious mutation in GJB6 gene was detected in our study cohort.

Conclusion

The present data demonstrated that mutations in the GJB6 gene are unlikely to be a major cause of non-syndromic deafness in Asian Indians.     

Auditory function in women with autoimmune inner ear diseases and their offspring

Objective

The precise cause of congenital sensorineural hearing loss (CSNHL) is unclear in many cases. In a previous study we found that offspring from guinea pigs with autoimmune sensorineural hearing loss (ASNHL) exhibited signs of SNHL. Here we studied women with autoimmune inner ear diseases (AIED) and their offspring. Our aim was to determine if autoimmune damage may be one of the causes of CSNHL.

Methods

Thirty-eight pregnant women with AIED were recruited. Thirty-three had ASNHL; one with autoimmune delayed endolymphatic hydrops (ADEH) and four with autoimmune Meniere's disease (AIMD). The following were assessed in all women: audiogram, auditory brain stem response (ABR), otoacoustic emission (OAE), vestibular function test and presence of inner ear antigens. The following were assessed in offspring from these women: OAE, ABR and presence of inner ear antigens.

Results

Five of the 38 children born to women with AIED had SNHL (an incidence much higher than normal). OAEs were not inducible in these children shortly after birth or within 46-100 days after birth. Abnormal ABR findings were apparent in these five children and inner ear antigens were detected in three of the five children (the mother's of these children were also positive for inner ear antigens).

Conclusions

These preliminary findings suggest that the prevalence of congenital ASNHL may be increased in offspring born to women with AIED.     

Prevalence of the mitochondrial A 1555G mutation in Moroccan patients with non-syndromic hearing loss

Mutations in mitochondrial DNA (mtDNA), especially the A1555G transition in the 12S rRNA gene, are one of the causes of both aminoglycoside-induced and non-syndromic sensorineural hearing loss.

Objective

The aim of this study was to determine the prevalence of the A1555G mitochondrial mutation in Moroccan patients.

Methods

We performed molecular characterization by PCR-RFLP and direct sequencing of one hundred and sixty four patients (84 unrelated familial and 80 sporadic cases) with a congenital sensorineural non-syndromic hearing loss and one hundred normal hearing controls for the occurrence of the A1555G mutation.

Results

Mutational analysis of the mtDNA showed the presence of the homoplasmic A1555G mutation in three families, leading to a frequency of 3.6% similar to that reported for European-populations. No A1555G mutation was detected in sporadic and controls cases. However, we detected in twenty normal hearing controls a novel polymorphism A1557C, which was not found in patient samples. We further evidenced the presence of the A1438G mitochondrial polymorphism in four patients with sensorineural hearing loss and in five controls.

Conclusion

Our results show that the occurrence of the A1555G mutation in hearing impaired patient's accounts for 3.6% in a Moroccan patients and those novel mtDNA polymorphisms might contribute to a novel sub-haplogroup specific of the Magrheb.     

Parental and program's decision making in paediatric simultaneous bilateral cochlear implantation: Who says no and why?

Objective

To evaluate initial candidacy for bilateral simultaneous cochlear implantation in children.

Design

Prospective case series.

Setting

Tertiary academic pediatric hospital.

Participants

As part of our research protocol all children eligible for cochlear implantation were assessed for suitability to receive a simultaneous bilateral implant. Over a 12-month period (January to December 2007) 78 children received a total of 95 cochlear implants. Children with sequential second implants (24), revision cases (4), and out of province recipients (4) were excluded. The remaining 46 patients were assessed for bilateral simultaneous implantation.

Main outcome measures

Team/parental decision to proceed with bilateral simultaneous implantation.

Results

17 children (37%) received simultaneous bilateral implants. 29 children (63%) were not considered suitable for simultaneous bilateral implantation. Reasons included developmental delay (10), residual borderline hearing in the second ear (9), parental/patient refusal (6), abnormally poor speech development for age (2), and abnormal cochlear anatomy precluding implantation (2). None were considered unsuitable for the more prolonged operative procedure on medical grounds.

Conclusions

Although bilateral implantation is thought to produce the optimal auditory outcome, not all patients are suitable, nor do all parents wish to proceed, when assessed for simultaneous implantation. Some of these patients are likely to be candidates for sequential bilateral implantation in due course.