Early fitting in cochlear implant surgery: preliminary results.

PURPOSE: Cochlear implants are usually activated 3-5 weeks after surgery; to date, no universal protocol exists regarding switch on and fitting of these devices. The aim of the study was to assess safety and functional results of activation and fitting of cochlear implant within 24 h following surgery. METHODS: In this retrospective case-control study, 15 adult patients who underwent cochlear implant surgery, for a total of 20 cochlear implant procedures were analyzed. In particular, clinical safety and feasibility were investigated by examinating patients at activation and at each follow-up. Values of electrodes' impedance and most comfortable loudness (MCL) were analyzed from the time of surgery to 12 months after activation. Free-field pure tone average (PTA) was also recorded. RESULTS: No major or minor complications were reported and all patients could perform the early fitting. Activation modality influenced impedance values only in the short term but the differences were not statistically significant (p > 0.05). Mean MCL values in the early fitting group were lower than MCL of the late fitting in all follow-up sessions, and the difference was statistically significant (p < 0.05). The mean PTA was lower in the early fitting group but the difference was not statistically significant (p < 0.05). CONCLUSIONS: Early fitting of cochlear implants is safe, allows for an early rehabilitation and can have possible beneficial effects on stimulation levels and dynamic range.

Integrated Bimodal Fitting for Unilateral CI Users with Residual Contralateral Hearing.

BACKGROUND: The aim of this study was to compare, in users of bimodal cochlear implants, the performance obtained using their own hearing aids (adjusted with the standard NAL-NL1 fitting formula) with the performance using the Phonak Naìda Link Ultra Power hearing aid adjusted with both NAL-NL1 and a new bimodal system (Adaptive Phonak Digital Bimodal (APDB)) developed by Advanced Bionics and Phonak Corporations. METHODS: Eleven bimodal users (Naìda CI Q70 + contralateral hearing aid) were enrolled in our study. The users' own hearing aids were replaced with the Phonak Naìda Link Ultra Power and fitted following the new formula. Speech intelligibility was assessed in quiet and noisy conditions, and comparisons were made with the results obtained with the users' previous hearing aids and with the Naída Link hearing aids fitted with the NAL-NL1 generic prescription formula. RESULTS: Using Phonak Naìda Link Ultra Power hearing aids with the Adaptive Phonak Digital Bimodal fitting formula, performance was significantly better than that with the users' own rehabilitation systems, especially in challenging hearing situations for all analyzed subjects. CONCLUSIONS: Speech intelligibility tests in quiet settings did not reveal a significant difference in performance between the new fitting formula and NAL-NL1 fittings (using the Naída Link hearing aids), whereas the performance difference between the two fittings was very significant in noisy test conditions.

Very good performance with bimodal stimulation in a like-hybrid modality in a patient with profound bilateral sensorineural hearing loss with low-frequencies preservation.

In this work we describe the experimental protocol set up to obtain very good results in speech performance and in time course, with a subject presenting profound bilateral sensorineural hearing loss with low-frequencies preservation. We used a bimodal stimulation with a like-hybrid modality. Auditory functions have been analyzed by standard tonal and speech audiometry tests, and verbal perception test. The fitting protocol permitted the subject to reach a perception at 65 dB of 100% in a very short time. The subject showed a sufficient recovery of the language spectral information and a good integration of verbal information with high consonantal recognition is present. This case report shows the importance to realize a correct cochlear implant fitting and that, in the case of bimodal stimulation, it is very important to obtain the mutual adjustment of the two hearing aids. Moreover, this study enhances the importance of realizing a preservative surgery to make the most of cochlear implants capacity.

Feasibility and effectiveness of a population-based newborn hearing screening in an economically deprived region of Italy.

AIM: To describe the effectiveness of a population-based newborn hearing screening program in an economically deprived region of southern Italy. METHODS: A screening protocol was proposed for all newborns of the Campania region, starting on January, 2007. For infants identified with hearing loss, information on degree and type of hearing loss and presence of risk factors was collected. RESULTS: The infants born in the 3-year study period were 182,188. Among them, 146,026 (80%) were tested with OAE. Sensorineural hearing loss ≥40dBnHL was established for 159 infants (1.1×1000). Among the NICU and WIN infants, the rate of hearing loss was respectively 9×1000 and 0.67×1000. Follow-up information was available for 111 children (70%), as 48 (30%) got care in other regions or health facilities. Most infants were fitted hearing aids by 1 month after diagnosis and 15 children (13.5%) received a cochlear implant at a mean age of 25 months (SD 10). CONCLUSIONS: Even in a setting of population poverty, a universal newborn screening program can deliver satisfactory outcomes. The coverage and the tracking system of the program need to be improved, as well as the cooperation between public and private health services.

Hearing impairment in Parkinson's disease: expanding the nonmotor phenotype.

The objective of this study was to evaluate hearing impairment in patients affected by Parkinson's disease compared with hearing scores observed in normal age- and sex-matched controls. One hundred eighteen consecutive patients with a clinical diagnosis of Parkinson's disease were screened. Severity of motor symptoms and staging were measured with the Unified Parkinson's Disease Rating Scale (section III) and the Hoehn and Yahr scale. Audiometric evaluation consisted of a comprehensive audiologic case history and questionnaire, visual otoscopic examination, acoustic immittance measures (tympanogram and acoustic reflexes), pure tone audiometry, and measurement of brain stem auditory-evoked potentials. Healthy age- and sex-matched subjects were selected as the control group. One hundred six of 118 patients were enrolled. Pure tone audiometry revealed age-dependent high-frequency hearing loss in patients with Parkinson's disease compared with both normative values and values for healthy age- and sex-matched controls (75/106 [71%], χ(2) = 5.959, P = .02; 92/106 [86.8%] vs 60/106 [56.6%], χ(2) = 23.804, P < .001, respectively). Pure tone audiometry scores correlated with Hoehn and Yahr scale scores (P < .05). Brain stem auditory-evoked potentials were normal in all patients. Our patients with Parkinson's disease showed age-dependent peripheral, unilateral, or bilateral hearing impairment. Whether these auditory deficits are intrinsic to Parkinson's disease or secondary to a more complex impaired processing of sensorial inputs occurring over the course of illness remains to be determined. Because α-synuclein is located predominately in the efferent neuronal system within the inner ear, it could affect susceptibility to noise-induced hearing loss or presbycusis. It is feasible that the natural aging process combined with neurodegenerative changes intrinsic to Parkinson's disease might interfere with cochlear transduction mechanisms, thus anticipating presbycusis.

Mutational analysis for GJB2, GJB6, and GJB3 genes in Campania within a universal neonatal hearing screening programme.

OBJECTIVE: To determine the incidence of GJB2 and GJB3 mutations and of two deletions upstream of the GJB6 gene in infants of the Campania region of southern Italy. DESIGN: DNA samples from non-syndromic hearing-impaired infants enrolled in a neonatal screening programme for sensorineural hearing loss were analysed by PCR and by direct sequencing. The audiological features of infants with biallelic GJB2 mutations were also examined to identify genotype-phenotype correlations. STUDY SAMPLE: Molecular analyses were carried out in 129 affected and five unaffected infants. RESULTS: A genetic etiology of hearing loss was identified in 28% of infants, including several at environmental risk of hearing loss. Neither GJB6 nor GJB3 (a gene not previously investigated in the Campania population) mutations were found. CONCLUSIONS: This study confirms the importance of universal neonatal hearing screening. The identification of a genetic cause in infants at environmental risk indicates that such infants should be included when investigating etiology. We confirm that also in our geographical area, c.35delG homozygotes tend to have severe symmetrical hearing loss, whereas hearing impairment is milder in compound heterozygotes.

Screening for GJB2 and GJB6 gene mutations in patients from Campania region with sensorineural hearing loss.

The aim of this study was to screen 349 patients affected by sensorineural hearing loss (SNHL), mostly from the Campania region (southern Italy), for GJB2 gene mutations and for two deletions of the GJB6 gene (del GJB6 -D13S1830 and del GJB6 -D13S1854). We identified pathogenetic GJB2 mutations in 51 cases (15% of patients). No GJB6 mutation was found. We also examined the audiologic features of the patients for whom we had an etiologic diagnosis, in order to identify correlations between the severity of hearing loss and the type of mutation.

Age-related hearing loss in four Italian genetic isolates: an epidemiological study.

The objective of this study was to estimate the prevalence of hearing impairment in four genetically isolated Italian villages (Carlantino, Campora, Gioi-Cardile, and Stoccareddo), 1682 subjects were recruited from all the individuals participating in a multidisciplinary study. They underwent otoscopy and pure-tone audiometry and completed a questionnaire. The audiological data show that the percentage of impaired people increases with age and in particular becomes relevant aged over 40. For this reason we decided to compare the PTA values of individuals aged 40 or older. The PTA values of Stoccareddo and Carlantino are statistically different from PTAs of the other villages. Campora and Gioi-Cardile, both located within the Cilento National Park, have similar middle-low frequency PTA values while some differences are present at high frequencies. Using pedigrees it was possible to calculate the heritability of the trait. For Carlantino and Gioi-Cardile the percentage of the phenotype variation attributable to genetic variation is not significant, while for Campora the heritability value is 0.49 (p = 0.01) suggesting that genetic factors may have an important role.

Spatio-temporal pattern of vestibular information processing after brief caloric stimulation.

Processing of vestibular information at the cortical and subcortical level is essential for head and body orientation in space and self-motion perception, but little is known about the neural dynamics of the brain regions of the vestibular system involved in this task. Neuroimaging studies using both galvanic and caloric stimulation have shown that several distinct cortical and subcortical structures can be activated during vestibular information processing. The insular cortex has been often targeted and presented as the central hub of the vestibular cortical system. Since very short pulses of cold water ear irrigation can generate a strong and prolonged vestibular response and a nystagmus, we explored the effects of this type of caloric stimulation for assessing the blood-oxygen-level-dependent (BOLD) dynamics of neural vestibular processing in a whole-brain event-related functional magnetic resonance imaging (fMRI) experiment. We evaluated the spatial layout and the temporal dynamics of the activated cortical and subcortical regions in time-locking with the instant of injection and were able to extract a robust pattern of neural activity involving the contra-lateral insular cortex, the thalamus, the brainstem and the cerebellum. No significant correlation with the temporal envelope of the nystagmus was found. The temporal analysis of the activation profiles highlighted a significantly longer duration of the evoked BOLD activity in the brainstem compared to the insular cortex suggesting a functional de-coupling between cortical and subcortical activity during the vestibular response.