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Abstract Background Mutations in the GJB2 gene have been established as a major cause of inherited non syndromic deafness in different populations. A high number of sequence variations have been described in the GJB2 gene and the associated pathogenic effects are not always clearly established. The prevalence of a number of mutations is known to be population specific, and therefore population specific testing should be a prerequisite step when molecular diagnosis is offered. Moreover, population studies are needed to determine the contribution of GJB2 variants to deafness. We present our findings from the molecular diagnostic screening of the GJB2 and GJB6 genes over a three year period, together with a population-based study of GJB2 variants. Methods and results Molecular studies were performed using denaturing High Performance Liquid Chromatograghy (DHPLC) and sequencing of the GJB2 gene. Over the last 3 years we have studied 159 families presenting sensorineural hearing loss, including 84 with non syndromic, stable, bilateral deafness. Thirty families were genotyped with causative mutations. In parallel, we have performed a molecular epidemiology study on more than 3000 dried blood spots and established the frequency of the GJB2 variants in our population. Finally, we have compared the prevalence of the variants in the hearing impaired population with the general population. Conclusion Although a high heterogeneity of sequence variation was observed in patients and controls, the 35delG mutation remains the most common pathogenic mutation in our population. Genetic counseling is dependent on the knowledge of the pathogenicity of the mutations and remains difficult in a number of cases. By comparing the sequence variations observed in hearing impaired patients with those sequence variants observed in general population, from the same ethnic background, we show that the M34T, V37I and R127H variants can not be responsible for profound or severe deafness.

Objective: To analyze predictive factors of cochlear implant outcomes and postoperative complications in the elderly. Study Design: Prospective, longitudinal study performed in 10 tertiary referral centers. Methods: Ninety-four patients aged 65-85 years with a profound, postlingual hearing loss were evaluated before implantation, at time of activation, and 6 and 12 months after cochlear implantation. Speech perception and lipreading were measured using disyllabic word recognition in quiet and noise, and lipreading using disyllabic words and sentences. The influence of preoperative factors on speech perception in quiet and noise at 12 months was tested in a multivariate analysis. Complications, presence of tinnitus and of vestibular symptoms were collected at each evaluation. Results: The effect of age was observed only in difficult noisy conditions at SNR 0 dB. Lipreading ability for words and sentences was negatively correlated with speech perception in quiet and noise. Better speech perception scores were observed in patients with shorter duration of hearing deprivation, persistence of residual hearing for the low frequencies, the use of a hearing aid before implantation, the absence of cardiovascular risk factors, and in those with implantation in the right ear. General and surgical complications were very rare, and the percentage of vestibular symptoms remained stable over time. Conclusion:This study demonstrates that cochlear implantation in the elderly is a well-tolerated procedure and an effective method to improve communication ability. Advanced age has a low effect on cochlear implant outcome. Analyses of predictive factors in this population provide a convincing argument to recommend treatment with cochlear implantation as early as possible in elderly patients with confirmed diagnosis of a severe-to-profound hearing loss and with only limited benefit from hearing aid use in one ear. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Importance: The association between hearing impairment and cognitive decline has been established; however, the effect of cochlear implantation on cognition in profoundly deaf elderly patients is not known., Objective: To analyze the relationship between cognitive function and hearing restoration with a cochlear implant in elderly patients., Design, Setting, and Participants: Prospective longitudinal study performed in 10 tertiary referral centers between September 1, 2006, and June 30, 2009. The participants included 94 patients aged 65 to 85 years with profound, postlingual hearing loss who were evaluated before, 6 months after, and 12 months after cochlear implantation., Interventions: Cochlear implantation and aural rehabilitation program., Main Outcomes and Measures: Speech perception was measured using disyllabic word recognition tests in quiet and in noise settings. Cognitive function was assessed using a battery of 6 tests evaluating attention, memory, orientation, executive function, mental flexibility, and fluency (Mini-Mental State Examination, 5-word test, clock-drawing test, verbal fluency test, d2 test of attention, and Trail Making test parts A and B). Quality of life and depression were evaluated using the Nijmegen Cochlear Implant Questionnaire and the Geriatric Depression Scale-4., Results: Cochlear implantation led to improvements in speech perception in quiet and in noise (at 6 months: in quiet, 42% score increase [95% CI, 35%-49%; P < .001]; in noise, at signal to noise ratio [SNR] +15 dB, 44% [95% CI, 36%-52%, P < .001], at SNR +10 dB, 37% [95% CI 30%-44%; P < .001], and at SNR +5 dB, 27% [95% CI, 20%-33%; P < .001]), quality of life, and Geriatric Depression Scale-4 scores (76% of patients gave responses indicating no depression at 12 months after implantation vs 59% before implantation; P = .02). Before cochlear implantation, 44% of the patients (40 of 91) had abnormal scores on 2 or 3 of 6 cognition tests. One year after implant, 81% of the subgroup (30 of 37) showed improved global cognitive function (no or 1 abnormal test score). Improved mean scores in all cognitive domains were observed as early as 6 months after cochlear implantation. Cognitive performance remained stable in the remaining 19% of the participants (7 of 37). Among patients with the best cognitive performance before implantation (ie, no or 1 abnormal cognitive test score), 24% (12 of 50) displayed a slight decline in cognitive performance. Multivariate analysis to examine the association between cognitive abilities before implantation and the variability in cochlear implant outcomes demonstrated a significant effect only between long-term memory and speech perception in noise at 12 months (SNR +15 dB, P = .01; SNR +10 dB, P < .001; and SNR +5 dB, P = .02)., Conclusions and Relevance: Rehabilitation of hearing communication through cochlear implantation in elderly patients results in improvements in speech perception and cognitive abilities and positively influences their social activity and quality of life. Further research is needed to assess the long-term effect of cochlear implantation on cognitive decline.