Cognitive Improvement After Cochlear Implantation in Older Adults With Severe or Profound Hearing Impairment: A Prospective, Longitudinal, Controlled, Multicenter Study.

OBJECTIVE: To compare the cognitive evolution of older adults with severe or profound hearing impairment after cochlear implantation with that of a matched group of older adults with severe hearing impairment who do not receive a cochlear implant (CI). DESIGN: In this prospective, longitudinal, controlled, and multicenter study, 24 older CI users were included in the intervention group and 24 adults without a CI in the control group. The control group matched the intervention group in terms of gender, age, formal education, cognitive functioning, and residual hearing. Assessments were made at baseline and 14 months later. Primary outcome measurements included the change in the total score on the Repeatable Battery for the Assessment of Neuropsychological Status for Hearing impaired individuals score and on its subdomain score to assess cognitive evolution in both groups. Secondary outcome measurements included self-reported changes in sound quality (Hearing Implant Sound Quality Index), self-perceived hearing disability (Speech, Spatial, and Qualities of Hearing Scale), states of anxiety and depression (Hospital Anxiety and Depression Scale), and level of negative affectivity and social inhibition (Type D questionnaire). RESULTS: Improvements of the overall cognitive functioning (p = 0.05) and the subdomain "Attention" (p = 0.02) were observed after cochlear implantation in the intervention group; their scores were compared to the corresponding scores in the control group. Significant positive effects of cochlear implantation on sound quality and self-perceived hearing outcomes were found in the intervention group. Notably, 20% fewer traits of Type D personalities were measured in the intervention group after cochlear implantation. In the control group, traits of Type D personalities increased by 13%. CONCLUSION: Intervention with a CI improved cognitive functioning (domain Attention in particular) in older adults with severe hearing impairment compared to that of the matched controls with hearing impairment without a CI. However, older CI users did not, in terms of cognition, bridge the performance gap with adults with normal hearing after 1 year of CI use. The fact that experienced, older CI users still present subnormal cognitive functioning may highlight the need for additional cognitive rehabilitation in the long term after implantation.

Bone Conduction Trial Device to Eliminate the Effect of Transcranial Attenuation: A Prospective Observational Study in Single-Sided Deaf Subjects.

OBJECTIVES: The contact miniTM (CM) is a nonimplantable, digital bone conduction device (BCD) consisting of 2 isolated units: an electronic housing, including the microphone, and a vibrator housing. The study investigated whether the CM can be used as an alternative test device for a BCD trial in single-sided deaf (SSD) adults with the microphone placed at the SSD ear and the vibrator at the normal-hearing (NH) ear (i.e., cross position). METHODS: Twenty SSD adults (mean age: 50 [±13.2] years) participated in a 2-week BCD trial with the CM on the headband in cross position. Prior to the trial, the subjects performed adaptive speech-in-noise tests in an unaided condition. After the trial, speech-in-noise tests were performed with the CM in cross position (CMcross) and ipsilateral position, i.e., both units at the SSD ear (CMipsi). Five different speech-in-noise configurations were used (S0N0; S0NNH; S0NSSD; S0°NNH+SSD; and SSSDNNH). Speech reception thresholds (SRT) were analyzed comparing the unaided, the CMcross condition, and the CMipsi condition. RESULTS: Friedman's test revealed no significant differences in SRTs between the CMcross, CMipsi, and the unaided condition for the S0N0, S0NNH, S0NSSD, and S0°NNH+SSD configuration. However, in the SSSDNNH configuration, a significant effect was found (p < 0.001). Wilcoxon pairwise comparisons with Bonferroni correction indicated that SRTs in the CMcross condition were significantly lower (i.e., better speech understanding) than those in the unaided (p < 0.001) and the CMipsi condition (p < 0.05). CONCLUSION: The CM may be a good alternative for patients with SSD, resulting in significantly better speech recognition when noise is presented to the NH ear and speech to the SSD ear. As the speech recognition results are better in the cross than the ipsilateral position, the CMcross might help to overcome the negative effect of transcranial attenuation during BCD trials.

Postoperative cognitive dysfunction after cochlear implantation.

PURPOSE: Postoperative cognitive dysfunction (PCD) is a subtle, prolonged deterioration in cognition after surgery. This complication has been frequently investigated, mainly after major (cardiac) surgery. However, the incidence after cochlear implantation is unknown. Therefore, the aim of the study was to investigate the incidence and possible risk factors of PCD in severely hearing-impaired older adults after cochlear implantation. METHODS: In a prospective cohort study, 26 older participants (age: M = 70, SD = 8 years), scheduled for cochlear implantation, were assessed prior to and 1 week after implantation by means of the Montreal Cognitive Assessment (MoCA). The incidence of PCD was calculated. In addition, the following possible risk factors were recorded: age, sex, education, duration of hearing impairment, preoperative signs of depression and anxiety, duration of anesthesia, anesthetic and surgical events and postoperative complications. RESULTS: The incidence of PCD was 11.5%, defined by a Z score of change in MoCA scores ≥ 1.96 (i.e., a decrease of ≥ 4 points). The incidence of PCD was corrected for practice effects by incorporating data from a reference group. Besides an effect of age on the postoperative cognitive performance, no significant risk factors were identified. CONCLUSIONS: The incidence of PCD after cochlear implantation is lower than after major surgeries, but higher than after other minor surgeries. Routine cognitive screening before and after cochlear implantation is recommended to identify patients with PCD and to provide additional care for these patients.

Qualities of Single Electrode Stimulation as a Function of Rate and Place of Stimulation with a Cochlear Implant.

OBJECTIVES: Although it has been shown previously that changes in temporal coding produce changes in pitch in all cochlear regions, research has suggested that temporal coding might be best encoded in relatively apical locations. The authors hypothesized that although temporal coding may provide useable information at any cochlear location, low rates of stimulation might provide better sound quality in apical regions that are more likely to encode temporal information in the normal ear. In the present study, sound qualities of single electrode pulse trains were scaled to provide insight into the combined effects of cochlear location and stimulation rate on sound quality. DESIGN: Ten long-term users of MED-EL cochlear implants with 31-mm electrode arrays (Standard or FLEX) were asked to scale the sound quality of single electrode pulse trains in terms of how "Clean," "Noisy," "High," and "Annoying" they sounded. Pulse trains were presented on most electrodes between 1 and 12 representing the entire range of the long electrode array at stimulation rates of 100, 150, 200, 400, or 1500 pulses per second. RESULTS: Although high rates of stimulation are scaled as having a Clean sound quality across the entire array, only the most apical electrodes (typically 1 through 3) were considered Clean at low rates. Low rates on electrodes 6 through 12 were not rated as Clean, whereas the low-rate quality of electrodes 4 and 5 were typically in between. Scaling of Noisy responses provided an approximately inverse pattern as Clean responses. High responses show the trade-off between rate and place of stimulation on pitch. Because High responses did not correlate with Clean responses, subjects were not rating sound quality based on pitch. CONCLUSIONS: If explicit temporal coding is to be provided in a cochlear implant, it is likely to sound better when provided apically. In addition, the finding that low rates sound clean only at apical places of stimulation is consistent with previous findings that a change in rate of stimulation corresponds to an equivalent change in perceived pitch at apical locations. Collectively, the data strongly suggest that temporal coding with a cochlear implant is optimally provided by electrodes placed well into the second cochlear turn.

Cognitive Function in Acquired Bilateral Vestibulopathy: A Cross-Sectional Study on Cognition, Hearing, and Vestibular Loss.

BACKGROUND: Several studies have demonstrated cognitive deficits in patients with bilateral vestibulopathy (BVP). So far, little attention has been paid to the hearing status of vestibular patients when evaluating their cognition. Given the well-established link between sensorineural hearing loss (SNHL) and cognitive decline and the high prevalence of SNHL in BVP patients, it is therefore uncertain if the cognitive deficits in BVP patients are solely due to their vestibular loss or might be, partially, explained by a concomitant SNHL. OBJECTIVE: To evaluate the link between cognition, hearing, and vestibular loss in BVP patients. DESIGN: Prospective cross-sectional analysis of cognitive performance in patients with BVP and control participants without vestibular loss. Both groups included subjects with a variety of hearing (dys)function. Cognition was assessed by means of the Repeatable Battery for the Assessment of Neuropsychological Status for Hearing Impaired Individuals (RBANS-H). RESULTS: Sixty-four BVP patients were evaluated and compared with 83 control participants. For each subscale and the totale RBANS-H scale a multiple linear regression model was fitted with the following variables: vestibular loss, hearing loss, age, gender, and education. Hearing loss seemed to be associated with worse outcome on the total RBANS-H scale and subscales immediate memory and language. Vestibular loss, on the other hand, was linked to worse performance on the attention subscale of the RBANS-H. Furthermore, we did not observe a correlation between saccular function and cognition. CONCLUSION: This study has found general cognitive deficits in a large sample size of BVP patients. Multiple linear regression models revealed that both vestibular and hearing dysfunction were associated with different subscales of the cognitive test battery, the RBANS-H. Whereas hearing loss was associated with worse performance on total RBANS-H score, immediate memory and language, vestibular loss was observed to negatively affect attention performance.

Cognitive outcomes after cochlear implantation in older adults: A systematic review.

OBJECTIVES: To critically assess the current status of the literature on cognitive outcomes after cochlear implantation in older adults. METHODS: Studies were identified by searching MEDLINE (PubMed) and Cochrane Library, and checking reference lists of relevant articles. No restrictions were imposed regarding language, publication date, or publication status. Eligibility criteria were as follows: (1) the study sample included older adults aged 50 or over with severe to profound bilateral hearing loss, (2) the participants received a multi-electrode cochlear implant, and (3) a cognitive test was performed before and after implantation. Risk of bias was assessed with respect to: (A) the suitability of the cognitive tests to examine cognition in hearing-impaired (HI) subjects, (B) the control of practice effects, (C) statistical methods, and (D) other sources of bias. RESULTS: Out of 2716 retrieved records, 6 were found eligible, examining a total of 166 patients. Five of these studies reported improvements in cognition postimplantation and one study did not observe significant changes. Control of practice effects and the statistical methods were the most common origin of observed bias. DISCUSSION: The currently reviewed studies performed pioneering work and are indispensable for the field. However, they do not provide conclusive evidence of improved cognitive outcomes after cochlear implantation in older adults. CONCLUSION: Well-designed studies with long follow-up periods are imperative to verify whether cochlear implantation influences cognition in older adults. New research is stimulated to use appropriate cognitive assessment tools for HI individuals, to control for practice effects, and to perform appropriate statistical tests.

Cognitive Performance of Severely Hearing-impaired Older Adults Before and After Cochlear Implantation: Preliminary Results of a Prospective, Longitudinal Cohort Study Using the RBANS-H.

OBJECTIVE: To evaluate cognitive change in severely hearing-impaired older adults after cochlear implantation. STUDY DESIGN: Prospective, longitudinal cohort study with assessments before, and at 6 and 12 months after implantation. PATIENTS: Twenty older adults (median age: 71.5 yr). MAIN OUTCOME MEASURES: Change in the Repeatable Battery for the Assessment of Neuropsychological Status for Hearing-impaired individuals (RBANS-H) total score and subdomain scores were used to assess cognitive evolution. In addition, change in best-aided speech audiometry in quiet (monosyllabic words) and in noise (Leuven Intelligibility Sentences Test [LIST]) was examined, as well as patient-reported measures of health-related quality of life (Nijmegen Cochlear Implant Questionnaire [NCIQ]), self-perceived hearing disability (Speech, Spatial, and Qualities of hearing Scale-12 [SSQ12]), sound quality (Hearing Implant Sound Quality Index-19 [HISQUI19]), and states of anxiety and depression (Hospital Anxiety and Depression Scale [HADS]). RESULTS: The RBANS-H total scores improved significantly after 12 months cochlear implant (CI) usage (p < 0.001). At subdomain level, significant improvements were observed in the immediate and delayed memory domain (p = 0.005 and p = 0.002, respectively), and to a lesser extent also in the attention domain (p = 0.047). Furthermore, speech perception in quiet and in noise improved significantly after 6 months and remained stable after 12 months. Similarly, a significant improvement was observed on all patient-reported measures after 6 months of CI usage. These results remained stable after 12 months, except for the HADS. CONCLUSIONS: A significant improvement in overall cognition after 12 months of CI usage was established. However, future research is imperative to further disentangle possible practice effects from the effects of the cochlear implantation. The significant, positive effect of cochlear implantation on speech perception and patient-reported measures was confirmed.

Impaired Cognitive Functioning in Cochlear Implant Recipients Over the Age of 55 Years: A Cross-Sectional Study Using the Repeatable Battery for the Assessment of Neuropsychological Status for Hearing-Impaired Individuals (RBANS-H).

Primary Objective: To compare cognitive functioning among experienced, unilateral cochlear implant (CI) recipients and normal-hearing (NH) controls by means of the Repeatable Battery for the Assessment of Neuropsychological Status for Hearing-impaired individuals (RBANS-H). Methods: Sixty-one post-lingually and bilaterally severely hearing-impaired CI recipients (median age: 71.0, range: 58.3 to 93.9 years) with at least 1 year of CI experience (median: 12.4, range: 1.1 to 18.6 years) and 81 NH control participants (median age: 69.9, range: 50.1 to 87.1 years) took part in this cross-sectional study. The RBANS-H was performed, as well as an audiometric assessment, including best-aided speech audiometry in quiet (monosyllabic words) and in noise (Leuven Intelligibility Sentences test). Results: The RBANS-H performances of the CI recipients (mean: 88.1 ± 14.9) were significantly poorer than the those of the NH participants (mean: 100.5 ± 13.2), with correction of age, sex, and education differences (general linear model: p = 0.001). The mean difference, corrected for the effects of these three demographic factors, was 8.8 (± 2.5) points. Additionally, in both groups, a significant correlation was established between overall cognition and speech perception, both in quiet and in noise, independently of age. Conclusion: Experienced, unilateral CI recipients present subnormal cognitive functioning, beyond the effect of age, sex and education. This has implications for auditory rehabilitation after CI and may highlight the need for additional cognitive rehabilitation in the long term after implantation. Long-term prospective and longitudinal investigations are imperative to improve our understanding of cognitive aging in severely hearing-impaired individuals receiving CIs and its association with CI outcomes.

Does Otovestibular Loss in the Autosomal Dominant Disorder DFNA9 Have an Impact of on Cognition? A Systematic Review.

Background and Purpose: Cognitive impairment has been observed in patients with bilateral vestibular loss (BVL) and in patients with sensorineural hearing loss (SNHL). DFNA9 is an autosomal dominant disorder that causes a combination of both sensory deficits by the 3rd to 5th decade. We therefore hypothesize a combined detrimental effect on cognition. The aim of this systematic review was to identify studies related to DFNA9 in general and its relationship with cognitive impairment more specifically. Materials and Methods: Several databases including Medline, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, ISI Web of Knowledge, and Web of Science were searched to accumulate information about DFNA9-mutations, including phenotype, genotype, pathophysiology, quality of life (QOL), and imaging in general and cognitive function more specifically. A qualitative analysis was performed on the 55 articles that qualified. Results: The clinical features of DFNA9 are different along the 24 COCH mutations, described up to now. Vestibular symptoms generally present themselves a few years after SNHL onset in mutations associated with the vWFA-domain although they can precede SNHL onset in other mutations associated with the LCCL-domain. QoL has not been studied extensively in DFNA9, although scarce work is available on the positive impact of cochlear implantation to rehabilitate hearing. No studies were found evaluating cognition in DFNA9 patients. Conclusion: Although cognitive impairment has been demonstrated in patients with hearing loss as well as in patients with BVL, no studies have been reported on the combination of both sensory deficits, such as in DFNA9. Further research is warranted to correlate otovestibular status with cognition.

The Repeatable Battery for the Assessment of Neuropsychological Status for Hearing Impaired Individuals (RBANS-H) before and after Cochlear Implantation: A Protocol for a Prospective, Longitudinal Cohort Study.

Background: Currently, an independent relationship between hearing loss and cognitive decline in older adults is suggested by large prospective studies. In general, cochlear implants improve hearing and the quality of life in severely to profoundly hearing impaired older persons. However, little is known about the effects of cochlear implantation on the cognitive evolution in this population. Aim of the study: The primary goal of this prospective, longitudinal cohort study is to explore the cognitive profile of severely to profoundly postlingually hearing impaired subjects before and after cochlear implantation. In addition, the current study aims to investigate the relationship between the cognitive function, audiometric performances, quality of life, and self-reliance in these patients. Methods: Twenty-five patients aged 55 or older, scheduled for cochlear implantation, will be enrolled in the study. They will be examined prior to implantation, at 6 and 12 months after implantation and annually thereafter. The test battery consists of (1) a cognitive examination, using the Repeatable Battery for the Assessment of Neuropsychological Status adapted for Hearing impaired persons (RBANS-H), (2) an audiological examination, including unaided and aided pure tone audiometry, speech audiometry in quiet and speech audiometry in noise, (3) the administration of four questionnaires evaluating quality of life and subjective hearing benefit and (4) a semi-structured interview about the self-reliance of the participant. Discussion: Up until now only one study has been conducted on this topic, focusing on the short-term effects of cochlear implantation on cognition in older adults. The present study is the first study to apply a comprehensive neuropsychological assessment adapted for severely to profoundly hearing impaired subjects in order to investigate the cognitive capabilities before and after cochlear implantation. Trial registration: The present protocol is retrospectively registered at Clinical Trials (ClinicalTrials.gov) on June 9th, 2016. The first participant was enrolled on June 22nd, 2015. The protocol identifier is NCT02794350.