Posts Tagged ‘deafness’
Posted by Callier Library on October 9, 2009
Speechreading is a visual communicative skill for perceiving speech. In this study, we tested the effects of speech experience and deafness on the speechreading neural network in normal hearing controls and in two groups of deaf patients who became deaf either before (prelingual deafness) or after (postlingual deafness) auditory language acquisition. Magnetic signals from the cerebral cortex were recorded using a 306-channel magnetoencephalographic system. During magnetoencephalographic measurements, subjects were asked to perform a speechreading task from video clips of a female speaker either pronouncing syllables (speechreading condition) or showing closed-mouth movement. The sources of the evoked fields were modelled using equivalent current dipoles, the origins of which were fitted to the intracranial space based on magnetic resonance imaging findings. During the speechreading condition, the latency of auditory cortex activation was shorter in the postlingual deafness group than in the normal hearing control group. This parameter negatively correlated with speechreading scores measured clinically. Furthermore, as the duration of deafness increased, the latency of auditory cortex activation decreased exponentially. However, no such correlation was found in the prelingual deafness group which differed significantly from the two other groups in this respect. The latency of auditory cortex activation was significantly longer in the prelingual deafness group than in the two other groups. Thus, auditory experience may be crucial for the development of a normal neural network for speechreading. The pre-existing speechreading network in the postlingual deafness group is made more efficient by speeding up the neural response.
from Brain
Posted in Research | Tagged: deafness, MEG, speech experience, speechreading | Leave a Comment »
Posted by Callier Library on September 4, 2009
Conclusion
These results suggest that the postural stability of PD children improves as a result of adaptive sensory compensation, both visual and somatosensory. In addition, it appears that postural control is more highly dependent upon visual input than on somatosensory input.
from the International Journal of Pediatric Otorhinolaryngology
Posted in Research | Tagged: children, deafness, Sensory compensation, Single-limb standing balance, somatosensory, vision | Leave a Comment »
Posted by Callier Library on September 3, 2009
Results
The age-related changes in single-limb standing balance of the PD children were notably affected by sensory conditions, in contrast with those of the NH children, which were not influenced by sensory conditions. In conditions 1 and 3, where visual information was enabled, the mean time of maintaining single-limb standing for the PD children significantly increased with age, and even reached levels similar to those of the NH children. However, in condition 2, where visual input was removed, the deficit of single-limb standing balance in the PD children persisted. Condition 4 revealed no significant age-related changes in the PD children.
Conclusion
These results suggest that the postural stability of PD children improves as a result of adaptive sensory compensation, both visual and somatosensory. In addition, it appears that postural control is more highly dependent upon visual input than on somatosensory input.
from the International Journal of Pediatric Otorhinolaryngology
Posted in Research | Tagged: deafness, Keywords: Children, Sensory compensation, Single-limb standing balance, somatosensory, vision | Leave a Comment »
Posted by Callier Library on September 3, 2009
After five years of carrying out the program (between 2004 and 2008) a total number of 764,352 newborns were screened for hearing impairment. In the year 2008, National Newborn Hearing Screening Program (NNHSP) had given the chance for 2136 children with various types of hearing loss (320 with unilateral and 417 with bilateral hearing loss) to detect and refer to more experienced centers for further treatment.
Conclusions
Our results indicate that the necessity of newborn hearing screening is an indispensable issue. We have been targeted to develop National Newborn Hearing Screening Program (NNHSP) till given chance to access for every newborn in Turkey in next five years.
from the International Journal of Pediatric Otorhinolaryngology
Posted in Research | Tagged: deafness, hearing loss, Keywords: Newborn, Neonatal, screening | Leave a Comment »
Posted by Callier Library on August 27, 2009
Background: The GJB2 gene, mapping to chromosome 13q12, encodes a gap junction protein, connexin 26, and is responsible for certain forms of congenital deafness, such as DFNB1 and DFNA3. Mutations of this gene are responsible for about one half of severe autosomal recessive non-syndromic deafness. Methods: To determine whether GJB2 mutations are major causes of deafness in Chinese cochlear implant recipients, we enrolled 115 cochlear implant recipients for mutation screening. Results: The results showed that 36.5% (42/115) of all cochlear implant recipients and 41% (41/100) of non-syndromic deafness patients exhibit GJB2 mutations; only 1 inner ear malformation patient was detected with GJB2 mutations. The present study found 11 different variations in the GJB2 gene. Conclusion: The 235delC mutation was the most prevalent mutation, found in 18.3% (42/230 alleles) of all cochlear implant recipients and 21.0% (42/200 alleles) of the non-syndromic deafness group. Only 0.6% of GJB2 mutations were detected in the inner ear malformation group. The novel 187GT mutations are likely to be pathological mutations.
from ORL -Journal for Oto-Rhino-Laryngology and Its Related Specialties
Posted in Research | Tagged: Chinese, cochlear implant, deafness, GJB2 gene, mutation | Leave a Comment »
Posted by Callier Library on August 27, 2009
Background: The GJB2 gene, mapping to chromosome 13q12, encodes a gap junction protein, connexin 26, and is responsible for certain forms of congenital deafness, such as DFNB1 and DFNA3. Mutations of this gene are responsible for about one half of severe autosomal recessive non-syndromic deafness. Methods: To determine whether GJB2 mutations are major causes of deafness in Chinese cochlear implant recipients, we enrolled 115 cochlear implant recipients for mutation screening. Results: The results showed that 36.5% (42/115) of all cochlear implant recipients and 41% (41/100) of non-syndromic deafness patients exhibit GJB2 mutations; only 1 inner ear malformation patient was detected with GJB2 mutations. The present study found 11 different variations in the GJB2 gene. Conclusion: The 235delC mutation was the most prevalent mutation, found in 18.3% (42/230 alleles) of all cochlear implant recipients and 21.0% (42/200 alleles) of the non-syndromic deafness group. Only 0.6% of GJB2 mutations were detected in the inner ear malformation group. The novel 187GT mutations are likely to be pathological mutations.
from ORL -Journal for Oto-Rhino-Laryngology and Its Related Specialties
Posted in Research | Tagged: Chinese, cochlear implant, deafness, GJB2 gene, mutation | Leave a Comment »
Posted by Callier Library on June 19, 2009
Method: This examined 16 electronic data bases, plus bibliographies and references for published and unpublished studies. Abstracts were independently assessed against inclusion criteria by two researchers, results were compared and disagreements resolved. Included papers were then retrieved and further independently assessed in a similar way. Remaining studies had their data independently extracted by one of five reviewers and checked by another reviewer.
Results: From 1,580 abstracts and titles 15 studies were included. These were of moderate to poor quality. The large amount of heterogeneity in design and outcomes precluded meta-analysis. However, all studies reported that unilateral cochlear implants improved scores on all outcome measures. Additionally five economic evaluations found unilateral cochlear implants to be cost-effective for profoundly deaf children at UK implant centres.
from
Posted in Research | Tagged: child, cochlear implants, deafness, therapy | Leave a Comment »
Posted by Callier Library on May 5, 2009
Using Affymetrix 10K arrays, we searched for regions of homozygosity in 51 Turkish families including at least three members with either congenital or prelingual autosomal recessive non-syndromic sensorineural hearing loss (ARNSSNHL), and identified four families whose deafness mapped to the DFNB6 locus on 3p21 containing the TMIE gene. Mutation analysis revealed the p.R84W mutation in all four families. Screening of this mutation in 254 families with ARNSSNHL, without GJB2 mutations, revealed four additional affected families. A novel mutation was found in a non-complementary marriage between a deaf couple who were homozygous for p.R84W and p.W57X, respectively with two affected children who were compound heterozygotes. Six of the TMIE families originated from southeastern Anatolia, making p.R84W a common cause of hearing loss in that region with a relative frequency of 10.3% (95% CI is 2.5–18.1%). The overall prevalence of the p.R84W mutation in ARNSSNHL in Turkey is 2.4% (95% CI is 0.7–4.0%). Genotyping of single-nucleotide polymorphisms flanking the TMIE gene revealed a conserved haplotype, suggesting a single origin for p.R84W from a common ancestor 1250 years ago (95% CI is 650–2500 years). We conclude that p.R84W could be a common mutation in other Middle Eastern populations and should be included in mutation screening offered to individuals with ARNSSNHL.
from Clinical Genetics
Posted in Research | Tagged: Connexin 26, consanguinity, deafness, founder effect, hearing loss, TMIE | Leave a Comment »
Posted by Callier Library on April 30, 2009
High-intensity and/or prolonged exposure to noise causes temporary or permanent threshold shifts in auditory perception. Occupational exposure to solvents or administration of clinically important drugs, such as aminoglycoside antibiotics and cisplatin, also can induce permanent hearing loss. The mechanisms by which these ototoxic insults cause auditory dysfunction are still being unraveled, yet they share common sequelae, particularly generation of reactive oxygen species, that ultimately lead to hearing loss and deafness. Individuals are frequently exposed to ototoxic chemical contaminants (e.g., fuel) and noise simultaneously in a variety of work and recreational environments. Does simultaneous exposure to chemical ototoxins and noise potentiate auditory dysfunction? Exposure to solvent vapor in noisy environments potentiates the permanent threshold shifts induced by noise alone. Moderate noise levels potentiate both aminoglycoside- and cisplatin-induced ototoxicity in both rate of onset and in severity of auditory dysfunction. Thus, simultaneous exposure to chemical ototoxins and moderate levels of noise can potentiate auditory dysfunction. Preventing the ototoxic synergy of noise and chemical ototoxins requires removing exposure to ototoxins and/or attenuating noise exposure levels when chemical ototoxins are present.
from Seminars in Hearing
Posted in Research | Tagged: deafness, noise, ototoxic drugs, ototoxins, synergistic effects | 1 Comment »
Posted by Callier Library on April 28, 2009
CONCLUSIONS. Permanent hearing loss remains an adverse outcome of extreme prematurity, complicated by significant delayed-onset and progressive loss. Prolonged supplemental oxygen use is a marker for predicting permanent hearing loss; this requires detailed analysis of the pathophysiologic features, to reduce the prevalence of permanent hearing loss.
from Pediatrics
Posted in Research | Tagged: auditory neuropathy, deafness, outcomes, prematurity, sensorineural hearing loss | Leave a Comment »
Posted by Callier Library on April 17, 2009
CONCLUSION: the auditory thresholds of individuals with ages between 50 and 70 years are worse for the group that is exposed to noise. Noise is a higher risk factor than age when considering neurossensorial hearing losses.
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from Pró-Fono Revista de Atualização Científica
Posted in Research | Tagged: adult, deafness, hearing loss, Noise Effects, Noise-induced | Leave a Comment »
Posted by Callier Library on March 30, 2009
There have been no reports of children with confirmed congenital SNHL secondary to in utero syphilis infection. Newborns with positive syphilis serology should have hearing screening performed at birth and receive treatment with an appropriate course of penicillin therapy. Longitudinal hearing screening is recommended for all pediatric patients with congenital syphilis, as further studies documenting longitudinal audiometric data for patients previously treated either fully or partly for congenital syphilis are required.
from the International Journal of Pediatric Otorhinolaryngology
Posted in Research | Tagged: Congenital syphilis, deafness, hearing screening, Keywords: Hearing loss, Longitudinal, sensorineural | Leave a Comment »
Posted by Callier Library on March 24, 2009
Conclusion: There were no apparent differences in speech performance after cochlear implantation between patients with biallelic GJB2 and/or GJB6 mutations and those with deafness of unknown aetiology. These data have important implications for the selection of prognostic indicators of the outcome of cochlear implantation. Objective: To compare performance after cochlear implantation in children with mutations in GJB2 (connexin 26) and/or GJB6 (connexin 30) and children with deafness of unknown aetiology. Subjects and methods: Genetic analysis and speech performance evaluation was determined in 24 patients with (n=11) and without (n=13) biallelic GJB2 and/or GJB6 mutations who underwent cochlear implantation. Speech perception skills were measured 12 and 24 months after surgery. Each patient was classified in accordance with the speech perception category (SPC). Results: Overall, the two groups showed similar significant improvement in speech perception after implantation.
from Acta Oto-Laryngologica
Posted in Research | Tagged: cochlear implant, Connexin 26, connexin 30, deafness, GJB2, GJB6, hearing loss, speech perception | Leave a Comment »
Posted by Callier Library on March 13, 2009
Abstract
The purpose of this paper was to present estimates of costs and effects of selected interventions for hearing impairment in Africa and Asia. The method used mathematical simulation models on the basis of WHO burden of disease information, and WHO-CHOICE costing databases. Findings showed that in both regions, screening strategies for hearing impairment and delivery of hearing aids cost between I$1000 and I$1600 per DALY, with passive screening being the most efficient intervention. Active screening at schools and in the community are somewhat less cost-effective. In the treatment of chronic otitis media, aural toilet in combination with topical antibiotics costs is more efficient than aural toilet alone, and costs between I$11 and I$59 in both regions. The treatment of meningitis with ceftriaxone costs between I$55 and I$217 at low coverage levels, in both regions. In more absolute terms, the vast majority of all considered intervention strategies are cost-effective strategies according to international benchmarks, in both regions concerned. In conclusion, various strategies are economically attracti&v;e to reduce the disease burden of hearing impairment around the world.
from the International Journal of Audiology
Posted in Research | Tagged: Cost-effectiveness, Costs, deafness, Economic analysis, hearing impairment, Modelling | Leave a Comment »
Posted by Callier Library on February 26, 2009
Conclusion: Exposing patients to the risk of possible balance disorders associated with cochlear implantation is justified in view of the hearing rehabilitation achieved, even with today’s broader indications for cochlear implantation. However, patients should in any case be informed about the possibility and quality of post-operative vertigo symptoms.
from the Journal of Laryngology and Otology
Posted in Research | Tagged: deafness, hearing disorders, cochlear implantation, questionnaires, Key wordsVertigo, Vestibular Labyrinth | Leave a Comment »