Holistic assessment of cochlear implant outcomes using the international classification of functioning disability and health model: data analysis of a longitudinal prospective multicenter study

PURPOSE

To study outcome after cochlear implantation using the Cochlear Implant (CI) outcome assessment protocol based on the International Classification of Functioning, Disability and Health (ICF) model (CI-ICF).

METHODS

Raw data of a prospective, longitudinal, multicenter study was analyzed. Seventy-two CI candidates were assessed preoperatively and six months postoperatively using the CI-ICF protocol. Following tools were used: (1) Work Rehabilitation Questionnaire (WORQ), (2) Abbreviated Profile of Hearing Aid Benefit (APHAB), (3) Audio Processor Satisfaction Questionnaire (APSQ), (4) Speech, Spatial, and Qualities of Hearing Scale (SSQ12), (5) Hearing Implant Sound Quality Index (HISQUI19), (6) Nijmegen CI Questionnaire (NCIQ) (7) pure tone audiometry, (8) speech audiometry, (9) sound localization.

RESULTS

There was a significant improvement of speech discrimination in quiet (p = 0.015; p < 0.001) and in noise (p = 0.041; p < 0.001), sound detection (p < 0.001), tinnitus (p = 0.026), listening (p < 0.001), communicating with-receiving-spoken messages (p < 0.001), conversation (p < 0.001), family relationships (p < 0.001), community life (p = 0.019), NCIQ total score and all subdomain scores (p < 0.001). Subjective sound localization significantly improved (p < 0.001), while psychometric sound localization did not. There was no significant subjective deterioration of vestibular functioning and no substantial change in sound aversiveness. CI users reported a high level of implant satisfaction postoperatively.

CONCLUSION

This study highlights the positive impact of cochlear implantation on auditory performance, communication, and subjective well-being. The CI-ICF protocol provides a holistic and comprehensive view of the evolution of CI outcomes.

Intraoperative assessment of cochlear nerve functionality in various vestibular schwannoma scenarios: Lessons learned

The use of cochlear implants (CIs) is on the rise for patients with vestibular schwannoma (VS). Besides CI following tumor resection, new scenarios such as implantation in observed and/or irradiated tumors are becoming increasingly common. A significant emerging trend is the need of intraoperative evaluation of the functionality of the cochlear nerve in order to decide if a CI would be placed. The purpose of this paper is to explore the experience of a tertiary center with the application of the Auditory Nerve Test System (ANTS) in various scenarios regarding VS patients. The results are compared to that of the studies that have previously used the ANTS in this condition. Patients with unilateral or bilateral VS (NF2) who were evaluated with the ANTS prior to considering CI in a tertiary center between 2021 and 2023 were analyzed. The presence of a robust wave V was chosen to define a positive electrical auditory brainstem response (EABR). Two patients underwent promontory stimulation (PromStim) EABR previous to ANTS evaluation. Seven patients, 2 NF-2 and 5 with sporadic VS were included. The initial scenario was simultaneous translabyrinthine (TL) tumor resection and CI in 3 cases while a CI placement without tumor resection was planned in 4 cases. The ANTS was positive in 4 cases, negative in 2 cases, and uncertain in one case. Two patients underwent simultaneous TL and CI, 1 patient simultaneous TL and auditory brainstem implant, 3 patients posterior tympanotomy with CI, and 1 patient had no implant placement. In the 5 patients undergoing CI, sound detection was present. There was a good correlation between the PromStim and ANTS EABR. The literature research yielded 35 patients with complete information about EABR response. There was one false negative and one false positive case; that is, the 28 implanted cases with a present wave V following tumor resection had some degree of auditory perception in all but one case. The ANTS is a useful intraoperative tool to asses CI candidacy in VS patients undergoing observation, irradiation or surgery. A positive strongly predicts at least sound detection with the CI.

Meludia platform as a tool to evaluate music perception in pediatric and adult cochlear implant users

PURPOSE

Music perception is one of the greatest challenges for cochlear implant (CI) users. The aims of this study were: (i) to evaluate the music perception of CI users using the online Meludia music training program as music testing platform, (ii) to compare performance among three age groups, and (iii) to compare CI users with their normal hearing (NH) peers.

METHODS

138 individuals participated, divided between children (6-10 y), adolescents (11-16 y), and adults (≥ 17 y). Five music perception tasks were evaluated: Rhythm, Spatialization, Stable/unstable, Melody, and Density. We also administered the music related quality of life (MuRQoL) questionnaire for adults, and a music questionnaire for pediatric population (6-16 y) (MuQPP).

RESULTS

A significantly higher percentage of the adolescent CI users completed the five tasks compared to the other age groups. Both pediatric and adolescent CI users had similar performance to their NH peers in most categories. On the MuRQoL, adult NH listeners reported more music exposure than CI users (3.8 ± 0.6 vs 3.0 ± 0.6, p < 0.01), but both groups reported similar levels of perceived music importance (3.4 ± 0.7 vs 3.2 ± 1.1, p = 0.340). On the MuQPP, pediatric CI users who scored highly on music perception also had higher reported questionnaire scores (54.2 ± 12.9 vs 40.9 ± 12.1, p = 0.009).

CONCLUSIONS

Meludia can be used to evaluate music perception and to use for music training in CI users of all ages. Adolescents had the highest performance in most musical tasks. Pediatric CI users were more similar to their NH peers. The importance of music in adult CI users was comparable to their NH peers.

Objective and Subjective Assessment of Music Perception and Musical Experiences in Young Cochlear Implant Users

For many individuals, music has a significant impact on the quality and enjoyability of life. Cochlear implant (CI) users must cope with the constraints that the CI imposes on music perception. Here, we assessed the musical experiences of young CI users and age-matched controls with normal hearing (NH). CI users and NH peers were divided into subgroups according to age: children and adolescents. Participants were tested on their ability to recognize vocal and instrumental music and instruments. A music questionnaire for pediatric populations (MuQPP) was also used. CI users and NH peers identified a similar percentage of vocal music. CI users were significantly worse at recognizing instruments (p < 0.05) and instrumental music (p < 0.05). CI users scored similarly to NH peers on the MuQPP, except for the musical frequency domain, where CI users in the children subgroup scored higher than their NH peers (p = 0.009). For CI users in the children subgroup, the identification of instrumental music was positively correlated with music importance (p = 0.029). Young CI users have significant deficits in some aspects of music perception (instrumental music and instrument identification) but have similar scores to NH peers in terms of interest in music, frequency of music exposure, and importance of music.

Is Age a Limiting Factor for Audiological Results in Active Middle Ear Implants?

Active middle ear implants (AMEI) are implantable options for patients with sensorineural, conductive, or mixed hearing loss who are not good candidates for hearing aids. The aim of this study was to compare audiological, surgical, quality of life, and sound quality outcomes in adults <60 and ≥60 years receiving an AMEI. Twenty adult patients who underwent AMEI implantation were divided into two groups, <60 and ≥60 y. Preoperative tests included pure-tone average and speech discrimination score (SDS) at 65 dB for disyllabic words in quiet. Postoperative measures included AMEI-aided bone conduction threshold, free-field warble-tone threshold, and SDS at 65 dB for disyllabic words in quiet 12 months after the AMEI fitting. Subjective benefit was evaluated using the Nijmegen Cochlear Implant Questionnaire (NCIQ), Glasgow Benefit Inventory (GBI), and Hearing Implant Sound Quality Index (HISQUI19). Mean functional gain was 32 and 30 dB, and SDS at 65 dB improved from 19 to 95% and from 31 to 84% in the <60 and ≥60 y groups, respectively. All NCIQ domains improved following surgery, and all patients had a positive overall GBI score. The mean HISQUI19 score was 97 in both age groups. AMEIs are an effective hearing restoration method for older adults suffering from conductive or mixed hearing loss.

QoL, CIs, QALYs, and Individualized Rehabilitation: The Clinical and Practical Benefits of Regularly Assessing the Quality of Life of Adult Cochlear Implant Recipients

This study aimed to report quality of life (QoL) scores in unilateral cochlear implant (CI) users and to generate guidance for clinicians on using QoL measures to individualize CI counselling and rehabilitation and to increase access to CIs as a mode of rehabilitation. Participants (n = 101) were unilateral CI users with single-sided deafness (SSD; n = 17), asymmetrical hearing loss (AHL; n = 26), or bilateral hearing loss (Uni; n = 58). Generic QoL was assessed via the Health Utilities Index (HUI-3), and disease-specific QoL was assessed via the Speech, Spatial, and Qualities of Hearing scale (SSQ12) and Nijmegen CI Questionnaire (NCIQ) at preimplantation and at 6 and 12 months of CI use. All groups had significantly increased HUI-3 scores at both intervals. The SSD group showed significant benefit on the SSQ12 at visit 3, the AHL group showed significant benefit on the SSQ12 and most NCIQ subdomains at both intervals, and the Uni group showed significant benefit with both tests at both intervals. Unilateral CI recipients demonstrate improved QoL within the first 12 months of device use. Regular assessment with generic and disease-specific questionnaires has the potential to play an important role in personalizing treatment and possibly in increasing access to CI provision.

Long-Term Non-Users of Transcutaneous Auditory Implants: Thirty Years of Experience at a Single Institution

Background: Although it is a recognized phenomenon, there is little published in the literature on the discontinuation of auditory implant use. Aim: To evaluate the incidence of device non-use of transcutaneous auditory implants. Patients and Methods: This is a retrospective study of all living individuals (children and adults) implanted at the La Paz Hospital (Madrid, Spain) between 1992-2015, with a follow-up examination endpoint of December 2022. 356 device recipients were included: 316 with cochlear implants (CI), 22 with middle-ear implants (Vibrant Soundbridge, VSB), and 18 with bone conduction implants (Bonebridge, BB). Results: Nine CI recipients (2.8%) were identified as non-users (mean follow-up 15.1 ± 5.4 years). The reasons for non-use were implant failure and reimplantation rejection, lack of benefit, non-attendance of rehabilitation sessions, loss of the audio processor, and cognitive and linguistic difficulties. None of them experienced any surgical complications. Six VSB recipients (27.3%) were device non-users (mean follow-up 11.4 ± 2.1 years). All of them experienced device failure or surgical complications. To date, none of the BB recipients is a non-user (mean follow-up 8.6 ± 1.1 years). Conclusion: The rates of non-use of transcutaneous auditory implants vary widely between different types of implants. Given the small proportion of non-users, information on what are the predictive factors could not be determined. The reasons for non-use should be carefully documented and used to guide careful patient selection to reduce the risk of non-use in future candidates.

A Novel Representation of Audiological and Subjective Findings for Acoustical, Bone Conduction and Direct Drive Hearing Solutions

Background: The benefit of hearing rehabilitation is often measured using audiological tests or subjective questionnaires/interviews. It is important to consider both aspects in order to evaluate the overall benefits. Currently, there is no standardized method for reporting combined audiological and patient reported subjective outcome measures in clinical practice. Therefore, this study focuses on showing the patient’s audiological, as well as subjective outcomes in one graph using data from an existing study. Method: The present paper illustrated a graph presenting data on four quadrants with audiological and subjective findings. These quadrants represented speech comprehension in quiet (unaided vs. aided) as WRS% at 65 dB SPL, speech recognition in noise (unaided vs. aided) as SRT dB SNR, sound field threshold (unaided vs. aided) as PTA4 in dB HL, wearing time and patient satisfaction questionnaire results. Results: As an example, the HEARRING graph in this paper represented audiological and subjective datasets on a single patient level or a cohort of patients for an active bone conduction hearing implant solution. The graph offered the option to follow the user’s performance in time. Conclusion: The HEARRING graph allowed representation of a combination of audiological measures with patient reported outcomes in one single graph, indicating the overall benefit of the intervention. In addition, the correlation and consistency between some results (e.g., aided threshold and aided WRS) can be better visualized. Those users who lacked performance benefits on one or more parameters and called for further insight could be visually identified.

The effect of risk factors on cognition in adult cochlear implant candidates with severe to profound hearing loss

Hearing loss has been identified as a major modifiable risk factors for dementia. Adult candidates for cochlear implantation (CI) represent a population at risk of hearing loss-associated cognitive decline. This study investigated the effect of demographics, habits, and medical and psychological risk factors on cognition within such a cohort. Data from 34 consecutive adults with post-lingual deafness scheduled for CI were analyzed. Pure tone audiometry (PTA4) and Speech Discrimination Score (SDS) were recorded. The Repeatable Battery for Assessment of Neuropsychological Status for Hearing impaired individuals (RBANS-H) was used to measure cognition. Demographics (sex, age, years of education), habits (smoking, alcohol intake, physical inactivity), and medical factors (hypertension, diabetes, traumatic brain injury) were evaluated. Depression was measured using the Hospital Anxiety and Depression Scale (HADS), and social inhibition with the Type D questionnaire (DS14). All participants (mean age 62 ± 15 years) suffered from severe to profound hearing loss (PTA4:129 ± 60 dB; SDS:14 ± 24%). The mean RBANS-H total score was 83 ± 16. Participants reported a mean of years of formal education of 12 ± 5 years. The prevalence of habits and medical risk factors was: physical inactivity (29%), body mass index >30 (28%), traumatic brain injury (25%), hypertension (24%), heavy alcohol consumption (13%), smoking (13%), and diabetes (0%). Regarding psychological factors, the mean scores of social inhibition and depression were 10 ± 6 and 6 ± 5, respectively. The number of years of education was significantly correlated with the RBANS-H total score (p < 0.001), and with the domains “Immediate memory” (p = 0.003), “Visuospatial/constructional” (p < 0.001), and “Attention” (p < 0.001). The mean RBANS-H total score in participants who had university studies or higher level (12/34) was 97 ± 9, with the remaining participants reporting a mean score of 75 ± 15. Men performed better in the “Visuospatial/constructional” (p = 0.008). Physical inactivity was associated with lower scores in the “Delayed memory” (p = 0.031); hypertension correlated with lower RBANS-H total scores (p = 0.025) and “Attention” (p = 0.006). Depression and social inhibition were negatively correlated with RBANS-H total score and with the “Immediate memory,” “Visuospatial/constructional,” and “Attention” (all p < 0.05). In adults with late-onset deafness scheduled to CI, educational level has a significant effect. Additionally, sex, physical inactivity, hypertension, and psychological traits of social inhibition and depression may also influence cognitive status. Long-term studies with more participants would enable us better understand the effects different risk factors on cognitive status.

Contribution and safety of the side-to-end hypoglossal-to-facial transfer in multidisciplinary facial reanimation

BACKGROUND

This study evaluates facial and tongue function in patients undergoing side-to-end hypoglossal-to-facial transfer (HFT) with additional techniques.

METHODS

Thirty-seven patients underwent a side-to-end HFT. Twelve had additional cross-face grafts, and 9 had an additional masseter-to-facial transfer. Facial was assessed with House-Brackmann (HB), Sunnybrook Facial Grading Scale (SFGS), and eFACE. Martins scale and the Oral-Pharyngeal Disability Index (OPDI) were used to assess tongue function.

RESULTS

Ninety-four percent of cases reached HB grades III-IV. Mean total SFGS score improved from 16 ± 15 to 59 ± 11, while total eFACE score from 52 ± 13 to 80 ± 5. Dual nerve transfers were a predictor for a better eFACE total score p = 0.034, β = 2.350 [95% CI, 0.184-4.516]), as well as for a higher SFGS total score (p = 0.036, β = 5.412 [95% CI, 0.375-10.449]). All patients had Martin's grade I. Mean postoperative OPDI scores were 84 ± 17 (local physical), 69 ± 16 (simple and sensory motor components), 82 ± 14 (complex functions), and 73 ± 22 (psychosocial).

CONCLUSIONS

The side-to-end HFT offers predictable facial function outcome and preserves tongue function in nearly all cases. Dual nerve transfers appear to improve the final outcome.

Effect of cochlear implantation on cognitive decline and quality of life in younger and older adults with severe-to-profound hearing loss

Purpose

(a) To measure the change in cognition, the improvement of speech perception, and the subjective benefit in people under and over 60 years following cochlear implantation. (b) To assess the relationship between cognition, demographic, audiometric, and subjective outcomes in both age groups.

Methods

28 cochlear implant (CI) users were assigned to the < 60y group and 35 to the ≥ 60y group. Cognition was measured using the Repeatable Battery for the Assessment of Neuropsychological Status for Hearing impaired individuals (RBANS-H); subjective benefit was measured using the Nijmegen Cochlear Implant Questionnaire (NCIQ); the Glasgow Benefit Inventory (GBI); the Hearing Implant Sound Quality Index (HISQUI₁₉); Speech, Spatial and Qualities of Hearing Scale (SSQ₁₂); and the Hospital Anxiety and Depression Scale (HADS).

Results

Prior to surgery: the RBANS-H total score positively correlated with the domains “Advanced sound”, “Self-esteem”, and “Social functioning” of NCIQ, and negatively with HADS scores. 12 months post-implantation: the RBANS-H total score increased in the < 60y (p = 0.038) and in the ≥ 60y group (p < 0.001); speech perception and subjective outcomes also improved; RBANS-H total score positively correlated with “Self-esteem” domain in NCIQ. Age and the RBANS-H total score correlated negatively in the ≥ 60y group (p = 0.026).

Conclusions

After implantation, both age groups demonstrated improved cognition, speech perception and quality of life. Their depression scores decreased. Age was inversely associated with cognition.

Quality of Life Following Cochlear Implantation in Patients With Menière's Disease

Background: Menière's disease (MD) is a disorder characterized by auditory and vestibular dysfunction that significantly deteriorates patients' quality of life (QoL). In addition to the management of vestibular symptoms, some patients with bilateral hearing loss meet criteria for cochlear implantation (CI).

Objectives: (1) To assess hearing results and QoL outcomes following CI in patients with MD. (2) To compare these results to a matched control group of patients who had undergone CI. (3) To analyse differences in MD patients who have undergone simultaneous or sequential labyrinthectomy or previous neurectomy.

Methods: A retrospective analysis of a study group of 18 implanted patients with MD and a matched control group of 18 implanted patients without MD, who had CI at a tertiary referral center. Hearing and speech understanding were assessed via pure-tone audiometry (PTA) and disyllabic perception tests in quiet. QoL was assessed via the Nijmegen Cochlear Implant Questionnaire (NCIQ), the Glasgow Benefit Inventory (GBI), the Speech, Spatial and Qualities of Hearing Scale (SSQ₁₂), and the Hearing Implant Sound Quality Index (HISQUI₁₉). The impact of MD ablative surgeries was analyzed in the study group (MD group).

Results: Mean pre-operative PTA thresholds were significantly lower in the MD group (103 vs. 121 dB). A significant improvement in hearing outcomes was observed following CI in both groups (p < 0.001), with a maximum Speech Discrimination Score of 64 and 65% disyllables at 65 dB for the MD and control group, respectively. Subjective outcomes, as measured by the NCIQ, GBI, SSQ₁₂, and HISQUI₁₉ did not significantly differ between groups. In the MD group, despite achieving similar hearing results, QoL outcomes were worse in patients who underwent simultaneous CI and labyrinthectomy compared to the rest of the MD group. Post-operative NCIQ results were significantly better in patients who had undergone a previous retrosigmoid neurectomy when compared to those who had undergone only CI surgery in the subdomains “basic sound perception” (p = 0.038), “speech” (p = 0.005), “activity” (p = 0.038), and “social interactions” (p = 0.038).

Conclusion: Patients with MD and severe hearing loss obtain hearing results and QoL benefits similar to other CI candidates. Delayed CI after labyrinthectomy or vestibular neurectomy can be performed with similar or better results, respectively, to those of other cochlear implanted patients. Patients who undergo simultaneous CI and labyrinthectomy may achieve similar hearing results but careful pre-operative counseling is needed.

Drug development for noise-induced hearing loss

INTRODUCTION

Excessive exposure to noise is a common occurrence that contributes to approximately 50% of the non-genetic hearing loss cases. Researchers need to develop standardized preclinical models and identify molecular targets to effectively develop prevention and curative therapies.

AREAS COVERED

In this review, the authors discuss the many facets of human noise-induced pathology, and the primary experimental models for studying the basic mechanisms of noise-induced damage, making connections and inferences among basic science studies, preclinical proofs of concept and clinical trials.

EXPERT OPINION

Whilst experimental research in animal models has helped to unravel the mechanisms of noise-induced hearing loss, there are often methodological variations and conflicting results between animal and human studies which make it difficult to integrate data and translate basic outcomes to clinical practice. Standardization of exposure paradigms and application of -omic technologies will contribute to improving the effectiveness of transferring newly gained knowledge to clinical practice.

Does bimodal hearing increase self-assessed abilities and hearing outcomes when compared to unilateral cochlear implantation?

Objective: The primary objective of this study was to compare the applicability and benefit of providing unilateral cochlear implant (CI) users with a contralateral hearing aid (HA).Design: This retrospective (case-control) study was conducted in a hospital-based CI centre. Participants self-assessed their hearing via two questionnaires (SSQ₁₂ and HISQUI₁₉). Objective postoperative speech perception was assessed via aided thresholds and speech perception tests (monosyllabic words, disyllabic words, and sentences) in quiet and noise.Study sample: A CI-only group (n = 113, mean age 55.1 ± 14.2 years) and a bimodal group (n = 50, mean age 56.7 ± 15.2) participated in the study.Results: No significant difference in SSQ₁₂ or HISQUI₁₉ scores was observed between groups. The bimodal group had a significantly better aided hearing level (p = 0.020) and speech discrimination score (p = 0.019).Conclusions: Bimodal (CI + HA) users have significantly better speech understanding than unilateral CI-only users, although this benefit may not be reflected in self-assessed outcomes. Counselling about bimodal hearing must cover expectations about potential benefits.

Confinement effect on the low temperature specific heat for ultrathin silicon nanowires: a first principles study

This work studied the phonon confinement effects at the low temperature specific heat of Si nanowires from first principles using density functional perturbation theory. The nanowires were modeled in the [0 0 1] direction for three different diameters, with the largest cross section being approximately 10 Å. The results indicate the specific heat can be described at low temperatures using a third-grade polynomial of the form c _v  =  λT  +  βT ²  +  γT³, where the coefficients of quadratic and cubic terms are almost nonexistent for small diameters. These terms begin to have relevance at larger diameters. Further analysis shows λ  >  β  >  γ, which shows the phonon confinement (λ) and surface atoms (β) become more important than the volumetric contribution (γ) for ultrathin nanowires at low temperatures.

Biomarkers in Vestibular Schwannoma-Associated Hearing Loss

Vestibular schwannomas (VSs) are benign tumors composed of differentiated neoplastic Schwann cells. They can be classified into two groups: sporadic VS and those associated with neurofibromatosis type 2 (NF2). VSs usually grow slowly, initially causing unilateral sensorineural hearing loss (HL) and tinnitus. These tumors cause HL both due to compression of the auditory nerve or the labyrinthine artery and due to the secretion of different substances potentially toxic to the inner ear or the cochlear nerve. As more and more patients are diagnosed and need to be managed, we are more than ever in need of searching for biomarkers associated with these tumors. Owing to an unknown toxic substance generated by the tumor, HL in VS may be linked to a high protein amount of perilymph. Previous studies have identified perilymph proteins correlated with tumor-associated HL, including μ-Crystallin (CRYM), low density lipoprotein receptor-related protein 2 (LRP2), immunoglobulin (Ig) γ-4 chain C region, Ig κ-chain C region, complement C3, and immunoglobulin heavy constant γ 3. Besides, the presence of specific subtypes of heat shock protein 70 has been suggested to be associated with preservation of residual hearing. It has been recently demonstrated that chemokine receptor-4 (CXCR4) is overexpressed in sporadic VS as well as in NF2 tumors and that hearing disability and CXCR4 expression may be correlated. Further, the genetic profile of VS and its relationship with poor hearing has also been studied, including DNA methylation, deregulated genes, growth factors, and NF2 gene mutations. The knowledge of biomarkers associated with VS would be of significant value to maximize outcomes of hearing preservation in these patients.

Lithium effect on the electronic properties of porous silicon for energy storage applications: a DFT study

Theoretical studies on the effect of Li on the electronic properties of porous silicon are still scarce; these studies could help us in the development of Li-ion batteries of this material which overcomes some limitations that bulk silicon has. In this work, the effect of interstitial and surface Li on the electronic properties of porous Si is studied using the first-principles density functional theory approach and the generalised gradient approximation. The pores are modeled by removing columns of atoms of an otherwise perfect Si crystal, dangling bonds of all surfaces are passivated with H atoms, and then Li is inserted on interstitial positions on the pore wall and compared with the replacement of H atoms with Li. The results show that the interstitial Li creates effects similar to n-type doping where the Fermi level is shifted towards the conduction band with band crossings of the said level thus acquiring metallic characteristics. The surface Li introduces trap-like states in the electronic band structures which increase as the number of Li atom increases with a tendency to become metallic. These results could be important for the application of porous Si nanostructures in Li-ion batteries technology.

The Role of Insulin-Like Growth Factor 1 in the Progression of Age-Related Hearing Loss

Aging is associated with impairment of sensorial functions and with the onset of neurodegenerative diseases. As pari passu circulating insulin-like growth factor 1 (IGF-1) bioavailability progressively decreases, we see a direct correlation with sensory impairment and cognitive performance in older humans. Age-related sensory loss is typically caused by the irreversible death of highly differentiated neurons and sensory receptor cells. Among sensory deficits, age-related hearing loss (ARHL), also named presbycusis, affects one third of the population over 65 years of age and is a major factor in the progression of cognitive problems in the elderly. The genetic and molecular bases of ARHL are largely unknown and only a few genes related to susceptibility to oxidative stress, excitotoxicity, and cell death have been identified. IGF-1 is known to be a neuroprotective agent that maintains cellular metabolism, activates growth, proliferation and differentiation, and limits cell death. Inborn IGF-1 deficiency leads to profound sensorineural hearing loss both in humans and mice. IGF-1 haploinsufficiency has also been shown to correlate with ARHL. There is not much information available on the effect of IGF-1 deficiency on other human sensory systems, but experimental models show a long-term impact on the retina. A secondary action of IGF-1 is the control of oxidative stress and inflammation, thus helping to resolve damage situations, acute or made chronic by aging. Here we will review the primary actions of IGF-1 in the auditory system and the underlying molecular mechanisms.

Using the HISQUI29 to assess the sound quality levels of Spanish adults with unilateral cochlear implants and no contralateral hearing

To evaluate cochlear implant (CI) users' self-reported level of sound quality and quality of life (QoL). Sound quality was self-evaluated using the hearing implant sound quality index (HISQUI29). HISQUI29 scores were further examined in three subsets. QoL was self-evaluated using the glasgow benefit inventory (GBI). GBI scores were further examined in three subsets. Possible correlations between the HISQUI29 and GBI were explored. Additional possible correlations between these scores and subjects' pure tone averages, speech perception scores, age at implantation, duration of hearing loss, duration of CI use, gender, and implant type were explored. Subjects derived a "moderate" sound quality level from their CI. Television, radio, and telephone tasks were easier in quiet than in background noise. 89 % of subjects reported their QoL benefited from having a CI. Mean total HISQUI29 score significantly correlated with all subcategories of the GBI. Age at implantation inversely correlated with the total HISQUI29 score and with television and radio understanding. Sentence in noise scores significantly correlated with all sound perception scores. Women had a better mean score in music perception and in telephone use than did men. CI users' self-reported levels of sound quality significantly correlated with their QoL. Cochlear implantation had a beneficial impact on subjects' QoL. Understanding speech is easier in quiet than in noise. Music perception remains a challenge for many CI users. The HISQUI29 and the GBI can provide useful information about the everyday effects of future treatment modalities, rehabilitation strategies, and technical developments.

Using the HISQUI29 to assess the sound quality levels of Spanish adults with unilateral cochlear implants and no contralateral hearing

To evaluate cochlear implant (CI) users' self-reported level of sound quality and quality of life (QoL). Sound quality was self-evaluated using the hearing implant sound quality index (HISQUI29). HISQUI29 scores were further examined in three subsets. QoL was self-evaluated using the glasgow benefit inventory (GBI). GBI scores were further examined in three subsets. Possible correlations between the HISQUI29 and GBI were explored. Additional possible correlations between these scores and subjects' pure tone averages, speech perception scores, age at implantation, duration of hearing loss, duration of CI use, gender, and implant type were explored. Subjects derived a "moderate" sound quality level from their CI. Television, radio, and telephone tasks were easier in quiet than in background noise. 89 % of subjects reported their QoL benefited from having a CI. Mean total HISQUI29 score significantly correlated with all subcategories of the GBI. Age at implantation inversely correlated with the total HISQUI29 score and with television and radio understanding. Sentence in noise scores significantly correlated with all sound perception scores. Women had a better mean score in music perception and in telephone use than did men. CI users' self-reported levels of sound quality significantly correlated with their QoL. Cochlear implantation had a beneficial impact on subjects' QoL. Understanding speech is easier in quiet than in noise. Music perception remains a challenge for many CI users. The HISQUI29 and the GBI can provide useful information about the everyday effects of future treatment modalities, rehabilitation strategies, and technical developments.

Validation of the Hearing Implant Sound Quality Index (HISQUI19) to assess Spanish-speaking cochlear implant users' auditory abilities in everyday communication situations

CONCLUSION

The Spanish-language HISQUI19 is a reliable and easy-to-use tool for quantifying the self-perceived level of auditory benefit that cochlear implant (CI) users experience in everyday listening situations.

OBJECTIVES

To validate the Spanish-language version of The Hearing Implant Sound Quality Index (HISQUI19), a questionnaire for quantifying the self-perceived level of auditory benefit that CI users experience in everyday listening situations.

METHODS

Adult Spanish-speaking subjects with a CI were asked to complete a Spanish-language version of the HISQUI19. Reliability of the questionnaire was determined using Cronbach's α coefficient; exploratory factor analyses with a rotated (varimax) factor solution was applied to check construct validity; external validity was confirmed using Pearson's correlation. Test-re-test analysis was also performed. The MED-EL Assessment Database was used to assist in the administration, reporting, and data collection.

RESULTS

Sixty-six of 77 subjects completed and returned the HISQUI19. The mean score auditory ability score (mean ± standard deviation) of the HISQUI19 was 79.9 ± 24.0, a 'moderate' auditory benefit. An inverse relationship was found between the HISQUI19 score and age at implantation. Gender and side of implantation did not influence self-perceived functioning. The objective measures (disyllables tested without lip-reading and in quiet) were correlated with the Total Score.

Which ear should we choose for cochlear implantation in the elderly: The poorer or the better? Audiometric outcomes, quality of sound, and quality-of-life results

CONCLUSIONS

Cochlear implantation in the poorer ear of an elderly patient does not predict poorer post-operative audiological, quality-of-life (QoL), and quality of sound results.

OBJECTIVES

To determine whether choosing the 'better' or the 'poorer' ear for cochlear implantation impacts performance outcome in an elderly population.

METHODS

Forty-two out of 73 elderly (≥ 60 years) cochlear implant users with some residual hearing in at least one ear were selected. Three criteria were used to group the patients as 'better' or 'poorer' ear implanted; (C1) based on previous use of hearing aid, (C2) pre-operative PTA, and (C3) pre-operative speech discrimination. The Glasgow Benefit Inventory (GBI) and the Hearing Implant Sound Quality Index (HISQUI) were used to measure QoL and quality of sound, respectively.

RESULTS

The mean post-operative PTA was 38.7 ± 7.2 dBHL. In quiet, the mean disyllabic SDS at 65dBSPL was 75.4 ± 18.5, whereas the discrimination of sentences was 95.0% ± 6.9. The mean total GBI score was 30.9 ± 21.8, 92.9% of patients reporting a positive score. The mean HISQUI score was 111.3 ± 36.0, which corresponds to 'moderate' sound quality. No significant differences were found between both groups in terms of audiological outcomes, HISQUI scores or GBI scores when considering each of the three criteria.

Costimulatory molecule programmed death-1 in the cytotoxic response during chronic hepatitis C

Hepatitis C virus (HCV)-specific CD8⁺ T cells play an important role in the resolution of HCV infection. Nevertheless, during chronic hepatitis C these cells lack their effector functions and fail to control the virus. HCV has developed several mechanisms to escape immune control. One of these strategies is the up-regulation of negative co-stimulatory molecules such us programmed death-1 (PD-1). This molecule is up-regulated on intrahepatic and peripheral HCV-specific cytotoxic T cells during acute and chronic phases of the disease, whereas PD-1 expression is low in resolved infection. PD-1 expressing HCV-specific CD8⁺ T cells are exhausted with impairment of several effector mechanisms, such as: type-1 cytokine production, expansion ability after antigen encounter and cytotoxic ability. However, PD-1 associated exhaustion can be restored by blocking the interaction between PD-1 and its ligand (PD-L1). After this blockade, HCV-specific CD8⁺ T cells reacquire their functionality. Nevertheless, functional restoration depends on PD-1 expression level. High PD-1-expressing intrahepatic HCV-specific CD8⁺ T cells do not restore their effector abilities after PD-1/PD-L1 blockade. The mechanisms by which HCV is able to induce PD-1 up-regulation to escape immune control are unknown. Persistent TCR stimulation by a high level of HCV antigens could favour early PD-1 induction, but the interaction between HCV core protein and gC1q receptor could also participate in this process. The PD-1/PD-L1 pathway modulation could be a therapeutic strategy, in conjunction with the regulation of others co-stimulatory pathways, in order to restore immune response against HCV to succeed in clearing the infection.

Role of chemokines and their receptors in viral persistence and liver damage during chronic hepatitis C virus infection

Chemokines produced in the liver during hepatitis C virus (HCV) infection induce migration of activated T cells from the periphery to infected parenchyma. The milieu of chemokines secreted by infected hepatocytes is predominantly associated with the T-helper cell/Tc1 T cell (Th1/Tc1) response. These chemokines consist of CCL3 (macrophage inflammatory protein-1 alpha; MIP-1 alpha), CCL4 (MIP-1 beta), CCL5 (regulated on activation normal T cell expressed and secreted; RANTES), CXCL10 (interferon-gamma-inducible protein-10; IP-10), CXCL11 (interferon-inducible T-cell alpha chemoattractant; I-TAC), and CXCL9 (monokine induced by interferon gamma; Mig) and they recruit T cells expressing either CCR5 or CXCR3 chemokine receptors. Intrahepatic and peripheral blood levels of these chemokines are increased during chronic hepatitis C. The interaction between chemokines and their receptors is essential in recruiting HCV-specific T cells to control the infection. When the adaptive immune response fails in this task, non-specific T cells without the capacity to control the infection are also recruited to the liver, and these are ultimately responsible for the persistent hepatic damage. The modulation of chemokine receptor expression and chemokine secretion could be a viral escape mechanism to avoid specific T cell migration to the liver during the early phase of infection, and to maintain liver viability during the chronic phase, by impairing non-specific T cell migration. Some chemokines and their receptors correlate with liver damage, and CXCL10 (IP-10) and CXCR3 levels have shown a clinical utility as predictors of treatment response outcome. The regulation of chemokines and their receptors could be a future potential therapeutic target to decrease liver inflammation and to increase specific T cell migration to the infected liver.

Role of chemokines and their receptors in viral persistence and liver damage during chronic hepatitis C virus infection

Chemokines produced in the liver during hepatitis C virus (HCV) infection induce migration of activated T cells from the periphery to infected parenchyma. The milieu of chemokines secreted by infected hepatocytes is predominantly associated with the T-helper/T-cytotoxic type-1 cell (Th1/Tc1) response. These chemokines consist of CCL3 (macrophage inflammatory protein-1α; MIP-1α), CCL4 (MIP-1β), CCL5 (regulated on activation normal T cell expressed and secreted; RANTES), CXCL10 (interferon-γ−inducible protein-10; IP-10), CXCL11 (interferon-inducible T-cell α chemoattractant; I-TAC), and CXCL9 (monokine induced by interferon γ; Mig) and they recruit T cells expressing either CCR5 or CXCR3 chemokine receptors. Intrahepatic and peripheral blood levels of these chemokines are increased during chronic hepatitis C. The interaction between chemokines and their receptors is essential in recruiting HCV-specific T cells to control the infection. When the adaptive immune response fails in this task, non-specific T cells without the capacity to control the infection are also recruited to the liver, and these are ultimately responsible for the persistent hepatic damage. The modulation of chemokine receptor expression and chemokine secretion could be a viral escape mechanism to avoid specific T cell migration to the liver during the early phase of infection, and to maintain liver viability during the chronic phase, by impairing non-specific T cell migration. Some chemokines and their receptors correlate with liver damage, and CXCL10 (IP-10) and CXCR3 levels have shown a clinical utility as predictors of treatment response outcome. The regulation of chemokines and their receptors could be a future potential therapeutic target to decrease liver inflammation and to increase specific T cell migration to the infected liver.

The role of CCR5/CXCR3 expressing CD8+ cells in liver damage and viral control during persistent hepatitis C virus infection

BACKGROUND/AIMS

CXCR3 and CCR5 play a major role in recruiting cytotoxic T cells (Tc) and secreting secondary type 1 cytokines (Tc1) in the liver. HCV could impair their expression as a survival mechanism. The role of these chemokine receptors on CD8+ cells in chronic hepatitis C is analysed.

METHODS

Serum, chemokines, peripheral blood and intrahepatic lymphocytes from chronic hepatitis C patients were studied. CXCR3/CCR5 expressing CD8+ cells were quantified by flow-cytometry. Serum chemokines concentration (CXCL10/CCL3) was measured by ELISA. Basal data were correlated with liver inflammation. Longitudinal data were obtained during treatment and correlated with virologic response.

RESULTS

CCR5/CXCR3 expressing CD8+ cells were enriched in the liver and correlated with inflammation. Chronic HCV patients presented the same frequency of CCR5(high)/CXCR3(high) expressing CD8+ cells in peripheral blood as in healthy controls but higher serum concentration of CXCL10/CCL3. Treatment with PEG-interferon alpha-2b plus ribavirin increased CCR5(high)/CXCR3(high) expressing CD8+ cells frequency in peripheral blood and decreased CXCL10/CCL3 serum concentration. Increase in CXCR3(high) expressing CD8+ cells after 24 weeks of treatment was correlated with SVR.

CONCLUSIONS

In chronic hepatitis C, anti-viral treatment induces an increase in CD8+ cells expressing chemokine receptors associated with Tc1 response and a reduction in their ligands. Achievement of viral control is associated with an increase in CXCR3(high) expressing CD8+ cells during treatment.

[Cyclosporin A causes oxidative stress and mitochondrial dysfunction in renal tubular cells]

Reactive oxygen species (ROS) have been implicated in cyclosporin A (CsA) nephrotoxicity. As mitochondria are one of the main sources of ROS in cells, we evaluated the role of CsA in mitochondrial structure and function in LLC-PK1 cells. We incubated cells with CsA 1 microM for 24 hours and studies were performed with flow citometry and confocal microscopy. We studied mitochondrial NAD(P)H content, superoxide anion (O2.-) production (MitoSOX Red), oxidation of cardiolipin of inner mitochondrial membrane (NAO) and mitochondrial membrane potential (DIOC2(3)). Also we analyzed the intracellular ROS synthesis (H2DCF-DA) and reduced glutation (GSH) of cells. Our results showed that CsA decreased NAD(P)H and membrane potential, and increased O2.- in mitochondria. CsA also provoked oxidation of cardiolipin. Furthermore, CsA increased intracellular ROS production and decreased GSH content. These results suggest that CsA has crucial effects in mitochondria. CsA modified mitochondrial physiology through the decrease of antioxidant mitochondrial compounds as NAD(P)H and the dissipation of mitochondrial membrane potential and increase of oxidants as O2.-. Also, CsA alters lipidic structure of inner mitochondrial membrane through the oxidation of cardiolipin. These effects trigger a chain of events that favour intracellular synthesis of ROS and depletion of GSH that can compromise cellular viability. Nephrotoxic cellular effects of CsA can be explained, at least in part, through its influence on mitochondrial functionalism.

[All-trans retinoic acid induces apoptosis in human mesangial cells: involvement of stress activated p38 kinase]

All-trans retinoic acid (AR-t) is used for treating acute promyelocytic leukemia and renal cell carcinoma and it also has therapeutic value in several animal models of renal disease. Among its renal targets, mesangial cells have been widely studied: they have both retinoic acid receptors (RAR) and retinoid X receptors (RXR) and the cell growth is inhibited when human mesangial cells are incubated with 1-10 microM AR-t. Although his effect has been related with the antiproliferative action of AR-t, there are no studies on the involvement of apoptosis in AR-t induced cell growth when higher concentrations of retinoid are used. Our studies show that 25 microM AR-t triggers mesangial cell apoptosis assessed by light and fluorescence microscopy (Giemsa stain and acridine orange stain, respectively), DNA electrophoresis, flow cytometry (annexin-V) and immunocytochemistry (TUNEL). AR-t induced apoptosis was not inhibited by preincubation with the RXR pan-antagonist HX531 nor with the RAR pan-antagonist AGN 193109, this suggesting RAR and RXIR are not involved in AR-t induced cell death. Previous results of our group showed that ERK (extracellular regulated kinase) and INK (c-Jun kinase), two members of the MAP (mitogen activated protein) kinase family, are involved in non apoptotic effects of AR-t on mesangial cells. Therefore we focussed on the stress activated p38 kinase, the third member of the MAPK family, to investigate its involvement in AR-t induced apoptosis. The results confirmed a role of p38 since: 1) preincubation with B5203589, a p38 inhibitor, inhibited ARA induced apoptosis; 2) incubation with AR-t induced p38 phosphorilation after few minutes and p38 remained phosphorilated for at least 8 hours and 3) AR-t induced p38 phosphorilation was inhibited by SB203589. These data suggest that AR-t might have toxic side effects on the kidney but also suggest that AR-t could be an useful inhibitor of pathological mesangial cell expansion.