Congenital Unilateral Deafness Research Articles

선천성 일측 농 환아에 동반한 뇌척수액누수 1예

선천성 일측 농 환아에 동반한 뇌척수액누수 1예

Cochlear Implantation in Children With Congenital Unilateral Deafness: A Case Series.

Cochlear implant is regarded as a treatment option for hearing rehabilitation of adults with unilateral sensorineural hearing loss. A clear benefit has been experienced in regard to speech comprehension in noise, localization, and quality of life. The aim of this study was to investigate the benefit of cochlear implantation for children with congenital unilateral hearing loss. Retrospective case series. Tertiary referral center; cochlear implant program. Ten children with congenital unilateral hearing loss. After extensive consultation with the families and intensive counseling, the children received a cochlear implant. Categories of auditory performance, speech discrimination in open set, subjective assessment by Speech, Spatial and Qualities scale questionnaire. Eight of ten children use their cochlear implant consistently on a daily basis. Two children who were equipped with an implanted device at a later age tend to nonuse of the device. The evaluation of binaural hearing in small children is still difficult and methods have to be developed to allow objective assessment.

Cochlear implantation in children with congenital unilateral deafness: Mid-term follow-up outcomes

ObjectivesAlthough cochlear implantation is widely used to treat unilateral deafness in adults, very little literature exists on its use and effects on the paediatric population. This report adds to the literature showing the mid-term follow-up outcomes achieved by these children. Material and methodsThree children with congenital unilateral deafness were studied after implantation. Speech perception in noise, and sound localization ability were evaluated using age-appropriate materials. ResultsThe preliminary data of our small group of 3 children with congenital unilateral profound hearing loss revealed that up to 3 years post-implantation, congenitally deaf children who received a cochlear implant after 4 years of age do not demonstrate binaural hearing benefits. ConclusionEarly intervention in the prelingual phase may be crucial for the development of binaural hearing.

Congenital unilateral deafness affects cerebral organization of reading.

It is known that early sensory deprivation modifies brain functional structure and connectivity. The aim of the present study was to investigate the neuro-functional organization of reading in a patient with profound congenital unilateral deafness. Using event-related potentials (ERPs), we compared cortical networks supporting the processing of written words in patient RA (completely deaf in the right ear since birth) and in a group of control volunteers. We found that congenital unilateral hearing deprivation modifies neural mechanisms of word reading. Indeed, while written word processing was left-lateralized in controls, we found a strong right lateralization of the fusiform and inferior occipital gyri activation in RA. This finding goes in the same direction of recent proposals that the ventral occipito-temporal activity in word reading seem to lateralize to the same hemisphere as the one involved in spoken language processing.

Unilateral Cochlear Nerve Deficiency in Children

Cochlear nerve deficiency (CND) is increasingly diagnosed in children with sensorineural hearing loss (SNHL). We sought to determine the prevalence of CND, its imaging characteristics, and correlations with audiologic phenotype in children with unilateral SNHL. Case series with chart review. Tertiary pediatric hospital. In 128 consecutive children with unilateral SNHL who underwent high-resolution magnetic resonance imaging, the diameters, area, and signal intensity of the cochlear nerve (CN) were measured and normalized to the ipsilateral facial nerve. Presence of CND was determined by comparison to normative data. Relationships among hearing loss severity, progression, and nerve size were investigated. Cochlear nerve deficiency was present in 26% of children with unilateral SNHL. Its prevalence was higher (48%) in severe to profound SNHL, especially when in infants (100%). Width of the bony cochlear nerve canal (BCNC) correlated strongly with relative CN diameter, density, and area (R = 0.5); furthermore, a narrow BCNC (<1.7 mm) strongly predicted CND. Severity of hearing loss modestly correlated with nerve size, although significant variability was observed. Progression never occurred unless there were other inner ear malformations, whereas in the non-CND group, it occurred in 22%. Ophthalmologic abnormalities were very common (67%) in CND children, particularly oculomotor disturbances. Cochlear nerve deficiency is a common cause of unilateral SNHL, particularly in congenital unilateral deafness. Width of the BCNC effectively predicts CND, a finding useful when only computed tomography imaging is available. In an ear with CND, hearing can be expected to remain stable over time. Diagnosis should prompt evaluation by an ophthalmologist.

Asymmetry of Temporal Processing in Listeners With Normal Hearing and Unilaterally Deaf Subjects

In general, auditory cortex on the left side of the brain is specialized for processing of acoustic stimuli with complex temporal structure including speech, and the right hemisphere is primary for spectral processing and favors tonal stimuli and music. This asymmetry in processing is further emphasized when hemisphere-favored stimuli are presented to the contralateral ear. The purpose of the first experiment is to further investigate the properties that dictate lateralized processing of auditory stimuli by ear and the relationship between auditory task and stimulus type. Next, it is not clear what compensation may exist for the loss of function of one ear and consequently, reduced access to functions primary performed in the opposite hemisphere, in the case of early unilateral profound hearing loss. The purpose of experiment 2 is to determine if any compensation for loss of function is seen in persons with early unilateral deafness. Experiment 1: Gap detection thresholds were determined in 30 right-handed listeners with normal hearing using wide-band noise markers (temporally complex), 400 and 4000 Hz pure tones presented individually to the left and right ears. Experiment 2: The same procedure was administered to listeners with early-onset, severe-to-profound unilateral deafness (seven left ear deaf and five right ear deaf) in the hearing ear alone. A significant right ear advantage was found for gap detection threshold using noise markers and a smaller left ear advantage was found for tonal stimuli. Listeners with unilateral deafness demonstrated that the hearing ear, left or right, performed in a manner similar to listeners with normal hearing. Results indicate that (1) gap marker, more than task, was the salient feature in determining laterality of processing in this experiment, (2) the two ears have distinct processing capacity based on stimulus type, and (3) compensation for loss is not apparent in persons with congenital unilateral deafness.

Hereditary Congenital Unilateral Deafness: A New Disorder?

Congenital unilateral deafness is a rare disorder. The prevalence rates are unknown. The prevalence of children with severe to profound hearing losses that are congenital (or acquired before the development of speech and language) is 0.5 to 3 per 1,000 live births. Evidently, congenital unilateral deafness must have a lower prevalence. The purpose of this research was to present a new disorder, hereditary congenital unilateral deafness. A pedigree is presented in which both male and female members display symptoms of congenital unilateral deafness. Two affected persons and a normal-hearing member of the family have vestibular abnormalities without dysequilibrium. The inheritance pattern of this new syndrome is not clear. We hypothesize that the disorder might be new. A family like this has never before been presented in the medical literature.

Hereditary unilateral deaf-mutism as a variable manifestation of bilateral deaf-mutism or hearing loss

A total of 2,519 patients with bilateral severe congenital deafness (deaf-mutism) from Central Switzerland were recorded during the period between 1834 to 1979. More recently, 31 persons with unilateral severe deafness were examined. By constructing genealogical charts going back to the 17th century, at least ten of these unilaterally deaf persons were shown to be related to patients with bilateral deafness (pedigrees I-IV). Some of them exhibited a more or less marked Klein- Waardenburg syndrome. The unilateral deafness of those patients was inherited and not acquired. Congenital unilateral deafness may be understood to be the result of the broad variability of the expressivity of acoustic defects.