Longitudinal trajectories of memory among middle-aged and older people with hearing loss: the influence of cochlear implant use on cognitive functioning.

Introduction: Cochlear implants (CI) are the gold standard intervention for severe to profound hearing loss, a known modifiable risk factor for dementia. However, it remains unknown whether CI use might prevent the age-related cognitive decline. Recent studies are encouraging but are limited, mainly by short follow-up periods and, for ethical reasons, lack of appropriate control groups. Further, as age-related cognitive decline is multifaceted and not linear, other statistical approaches have to be evaluated. Materials and methods: Immediate and delayed recall as measures of cognitive function were assessed in 75 newly implanted CI users (mean age 65.41 years ± 9.19) for up to 5 years (mean 4.5 ± 0.5) of CI use and compared to 8,077 subjects of the same age range from two longitudinal cohort studies, the Health and Retirement Study (HRS) and the English Longitudinal Study of Aging (ELSA). Linear and quadratic changes in cognitive trajectories were analyzed in detail using mixed growth models, considering possible confounders. Results: For CI users, the linear time slope showed a significant improvement in the specific domains (recall and delayed recall) over time. The quadratic time slope clearly indicated that the predicted change after CI provision followed an inverted U-shape with a predicted decline 2 years after CI provision. In the hearing-impaired group, a significant decline over time was found, with steeper declines early on and the tendency to flatten out in the follow-up. Conclusion: Cochlear implant use seems to boost cognitive trajectories in the first years after implantation. However, long-term prevention of dementia seems to need far more than restoration of hearing loss.

Validation of the German Montreal-Cognitive-Assessment-H for hearing-impaired.

Background: Hearing loss and dementia are highly prevalent in older age and often co-occur. Most neurocognitive screening tests are auditory-based, and performance can be affected by hearing loss. To address the need for a cognitive screening test suitable for people with hearing loss, a visual version of the Montreal-Cognitive-Assessment was developed and recently validated in English (MoCA-H), with good sensitivity and specificity for identifying cases of dementia. As the MoCA is known to perform differently across languages, revalidation of the German MoCA-H was necessary. The aim of the present study was to assess the diagnostic accuracy of the German MoCA-H among those with normal cognition, mild cognitive impairment (MCI) and dementia and to determine an appropriate performance cut- off. Materials and methods: A total of 346 participants aged 60-97 years (M = 77.18, SD = 9.56) were included; 160 were cognitively healthy, 79 with MCI and 107 were living with dementia based on the GPCOG and a detailed medical questionnaire as well as a comprehensive examination by a neurologist in case of cognitive impairment. Performance cut-offs for normal cognition, MCI and dementia were estimated for the MoCA-H score and z-scores using the English MoCA-H cut-off, the balanced cut-off and the Youden's Index. Results: A mean score of 25.49 (SD = 3.01) points in the German MoCA-H was achieved in cognitively healthy participants, 20.08 (SD = 2.29) in the MCI and 15.80 (SD = 3.85) in the dementia group. The optimum cut-off for the detection of dementia was ≤21 points with a sensitivity of 96.3% and a specificity of 90%. In the MCI group, a cut-off range between 22 and 24 points is proposed to increase diagnostic accuracy to a sensitivity and specificity of 97.5 and 90%, respectively. Conclusion: The German MoCA-H seems to be a sensitive screening test for MCI and dementia and should replace commonly used auditory-based cognitive screening tests in older adults. The choice of a cut-off range might help to better reflect the difficulty in clinical reality in detecting MCI. However, screening test batteries cannot replace a comprehensive cognitive evaluation.

Third-party disability in cochlear implant users.

OBJECTIVE: To date, auditory rehabilitation mainly focuses on the person with hearing impairment (PHI). This study aimed to analyse the burden of hearing loss on significant others (SOs), and to explore the impact of contextual and mediating psychosocial co-factors and auditory rehabilitation by cochlear implantation (CI). DESIGN AND STUDY SAMPLE: Third-party disability (SOS-HEAR) and quality of life (Nijmegen Cochlear Implant Questionnaire) were evaluated in 41 PHI scheduled for CI surgery and their close partners pre- and 6-month post-implantation. Further, age, hearing status, educational level, depressive symptoms (GDS-15), coping strategies (Brief-COPE), resilience (RS-13), stress (PSQ) of SOs and PHI were studied. RESULTS: Hearing loss imposes a burden on SOs, particularly in relation to changes in communication and socialisation. Third-party disability was higher in SOs of PHI with lower educational background (p = 0.04) and of advanced age (p = 0.008). Hearing status of SOs negatively correlated with SOS-HEAR (p = 0.04). After CI, quality of life of PHI and third-party disability of SOs improved (p < 0.001), except in relationship changes. SOs with higher pre-operative burden also experienced more third-party disability afterwards (p ≤ 0.003). CONCLUSION: Audiological rehabilitation should expand to include SOs in the rehabilitation process, as the burden experienced by SOs might persist even after CI.

Evaluation of the non-auditory neurocognitive test MoCA-HI for hearing-impaired.

Background: Since hearing loss and cognitive decline often co-occur among older adults, a cognitive screening test suitable for hearing-impaired people is of high clinical relevance. We report the first evaluation of a German language version of the Montreal Cognitive Assessment-Hearing Impaired version (MoCA-HI). Objective: The aim of the present study was to compare cognitively healthy participants with and without hearing loss, to examine the impact of age, sex, educational level and degree of hearing impairment on the German MoCA-HI performance, and to develop normative data. Material and methods: The German MoCA-HI was tested in 94 participants with normal or mild hearing impairment (group 1: 4PTA ≤ 40 dB on the better hearing ear) and 81 participants with moderate to profound hearing loss (group 2: 4PTA > 40 dB on the better hearing ear). Additionally, all participants performed the standard MoCA (version 8.2). Results: No significant group difference between group 1 and 2 was found in the MoCA-HI total score (p = 0.05). In contrast, group 1 performed significantly better than group 2 on the standard MoCA (p < 0.001). There was no difference between the MoCA and the MoCA-HI performance in group 1 (p = 0.12), whereas individuals of group 2 performed significantly better on the MoCA-HI than on the standard MoCA (p < 0.001). Test-retest reliability of the MoCA-HI was high (p < 0.001). Higher age (p < 0.001), male sex (p = 0.009) and lower education (p < 0.001) were associated with a lower overall MoCA-HI score. Based on the demographic data normative data were developed by a regression-based approach. Conclusion: The MoCA-HI is a cognitive screening test which is suitable for people with hearing impairment.

Can cochlear implantation prevent cognitive decline in the long-term follow-up?

Cognitive function and hearing are known to both decline in older adults. As hearing loss is proposed to be one modifiable risk factor for dementia, the impact of auditory rehabilitation on cognitive decline has been gaining increasing attention. Despite a large number of studies, long-term data are still rare. In a large prospective longitudinal monocentric study, 50 adults (aged ≥ 50 years) with severe postlingual bilateral hearing loss received a cochlear implant (CI). They underwent comprehensive neurocognitive testing prior to implantation (T1), at 12 months (T2) and up to 65 months (T3) after implantation. Various cognitive subdomains such as attention, inhibition, working memory, verbal fluency, mental flexibility and (delayed) recall were assessed by the computer-based non-auditory test battery ALAcog©. The observed trajectories of two exemplary cognitive subdomains (delayed recall and working memory) were then fitted over time using multilevel growth models to adjust for sociodemographic covariates and compared with 5-year longitudinal data from a sample of older adults from the representative Survey of Health, Aging and Retirement in Europe (SHARE) study. Postoperatively, auditory functions improved from 6.98% (SD 12.83) to 57.29% (SD 20.18) in monosyllabic speech understanding. Cognitive functions significantly increased from T1 to T3 in attention (p = 0.001), delayed recall (p = 0.001), working memory (OSPAN; p = 0.001), verbal fluency (p = 0.004), and inhibition (p = 0.002). A closer look at follow-up revealed that cognitive improvement could be detected between T1 and T2 and thereafter remained stable in all subtests (p ≥ 0.06). Additional longitudinal analysis confirmed these findings in a rigorous multilevel approach in two exemplary cognitive subdomains. In contrast to the SHARE data, there was no evidence for age-differential associations over time in CI recipients. This suggests that older adults benefit equally from cochlear implantation. CI users with worse preoperative cognitive skills experienced the most benefit (p < 0.0001). Auditory rehabilitation by cochlear implantation has a stimulating effect on cognitive functions beyond an improvement in speech understanding and an increased well-being. Large multicenter studies using standardized protocols have to be undertaken in the future to find out whether hearing restoration might help to prevent cognitive decline.

Cognition and Cognitive Reserve in Cochlear Implant Recipients.

At present, dementia is a hot topic. Hearing loss is considered to be a modifiable risk factor for cognitive decline. The underlying mechanism remains unclear and might be mediated by socioeconomic and psychosocial factors. Cochlear implantation has been shown not only to restore auditory abilities, but also to decrease mental distress and to improve cognitive functions in people with severe hearing impairment. However, the promising results need to be confirmed. In a prospective single-center study, we tested the neurocognitive abilities of a large group of 71 subjects with bilateral severe hearing impairment with a mean age of 66.03 (SD = 9.15) preoperatively and 6, 12, and 24 months after cochlear implantation using a comprehensive non-auditory computer-based test battery, and we also assessed the cognitive reserve (CR) [Cognitive Reserve Index (CRI)], health-related quality of life (QoL) (Nijmegen Cochlear Implant Questionnaire), and depression (Geriatric Depression Scale-15). Cognitive functions significantly increased after 6 months in attention (p = 0.00004), working memory (operation span task; p = 0.002), and inhibition (p = 0.0002); and after 12 months in recall (p = 0.003) and verbal fluency (p = 0.0048), and remained stable up to 24 months (p ≥ 0.06). The CR positively correlated with cognitive functions pre- and post-operatively (both p < 0.005), but postoperative improvement in cognition was better in subjects with poor CR (p = 0.003). Depression had only a slight influence on one subtest. No correlation was found among cognitive skills, quality of life, and speech perception (each p ≥ 0.05). Cochlear implantation creates an enriched environment stimulating the plasticity of the brain with a global positive impact on neurocognitive functions, especially in subjects with poor preoperative cognitive performance and low cognitive reserve.

Impact of Cochlear Implantation on Neurocognitive Subdomains in Adult Cochlear Implant Recipients.

INTRODUCTION: Age-related hearing loss affects about one-third of the population worldwide. Studies suggest that hearing loss may be linked to cognitive decline and auditory rehabilitation may improve cognitive functions. So far, the data are limited, and the underlying mechanisms are not fully understood. The study aimed to analyze the impact of cochlear implantation on cognition in a large homogeneous population of hearing-impaired adults using a comprehensive non-auditory cognitive assessment with regard to normal-hearing (NH) subjects. MATERIAL AND METHODS: Seventy-one cochlear implant (CI) candidates with a postlingual, bilateral severe or profound hearing loss aged 66.3 years (standard deviation [SD] 9.2) and 105 NH subjects aged 65.96 years (SD 9.4) were enrolled. The computer-based neurocognitive tool applied included 11 subtests covering attention (M3), short- and long-term memory (recall and delayed recall), working memory (0- and 2-back, Operation Span [OSPAN] task), processing speed (Trail Making Test [TMT] A), mental flexibility (TMT B), inhibition (cFlanker and iFlanker), and verbal fluency. CI patients underwent a neurocognitive testing preoperatively as well as 12 months postoperatively. Impact of hearing status, age, gender, and education on cognitive subdomains was studied. Additionally, after controlling for education and age, cognitive performance of CI subjects (n = 41) was compared to that of NH (n = 34). RESULTS: CI users achieved significantly better neurocognitive scores 12 months after cochlear implantation than before in most subtests (M3, [delayed] recall, 2-back, OSPAN, iFlanker, and verbal fluency; all p < 0.05) except for the TMT A and B. A significant correlation could be found between the postoperative improvement in speech perception and in the attentional task M3 (p = 0.01). Hearing status (p = 0.0006) had the strongest effect on attention, whereas education had a high impact on recall (p = 0.002), OSPAN (p = 0.0004), and TMT A (p = 0.005) and B (p = 0.003). Inhibition was mainly age-dependent with better results in younger subjects (p = 0.016). Verbal fluency was predicted by gender as females outperformed men (p = 0.009). Even after controlling for age and education NH subjects showed a significantly better performance than CI candidates in the recall (p = 0.03) and delayed recall (p = 0.01) tasks. Postoperatively, there was no significant difference between the 2 groups anymore. CONCLUSION: Impact of cochlear implantation on neurocognitive functions differs according to the cognitive subdomains. Postoperatively, CI recipients performed as good as age- and education-matched NH subjects.

Benefits of Cochlear Implantation in Middle-Aged and Older Adults.

INTRODUCTION: Nowadays cochlear implantation (CI) is the treatment of choice in adults in case conventional hearing devices fail. Besides speech perception, an improvement in quality of life and in cognitive performance has been reported. Thereby, the study focused on the impact of age. PARTICIPANTS AND METHODS: Thirty middle-aged (MA) between 50 and 64 years and 41 older subjects (OA) aged 65 and older with bilateral severe hearing loss performed a comprehensive computer-based neurocognitive test battery (ALAcog) pre- and 12 months post-implantation. Besides, monosyllabic speech perception in quiet (Freiburg monosyllabic speech test), health-related quality of life (HR-QoL, Nijmegen Cochlear Implant Questionnaire) and depressive symptoms (GDS-15) have been assessed. RESULTS: Both age groups significantly improved in all three categories after 12 months. No differences were evaluated between MA and OA regarding speech perception and HR-QoL pre- and post-operatively. In contrast, cognitive performance differed between the age groups: pre-operatively OA performed worse in most neurocognitive subdomains like working memory (p=0.04), inhibition (p=0.004), processing speed (p=0.003) and mental flexibility (p=0.01), post-operatively MA outperformed OA only in inhibition (p=0.01). Age only slightly influenced cognitive performance in MA, whereas in OA age per se tremendously impacted on working memory (p=0.04), inhibition (p=0.02), memory (p=0.04) and mental flexibility (p=0.01). Educational level also affected processing speed, mental flexibility (p=0.01) and working memory (p=0.01). This was more pronounced in OA. In both age groups, hearing status had a strong effect on attentional tasks (p=0.01). In MA, depressive symptoms were more influential on cognitive functioning and on HR-QoL than in OA. Improvement in quality of life (p=0.0002) and working memory (p=0.001) was greater for those with a higher pre-operative depression score. CONCLUSION: Speech perception and HR-QoL improved in hearing impaired, independently of age. Pre-operative differences in cognitive performance between OA and MA clearly attenuated 12 months after CI. Impact of comorbidities differed between age groups.

Impact of Hearing Loss on Geriatric Assessment.

BACKGROUND: Due to the aging society, the incidence of age-related hearing loss (ARHL) is strongly increasing. Hearing loss has a high impact on various aspects of life and may lead to social isolation, depression, loss of gain control, frailty and even mental decline. Comorbidity of cognitive and sensory impairment is not rare. This might have an impact on diagnostics and treatment in the geriatric setting. OBJECTIVE: The aim of the study was to evaluate the impact of hearing impairment on geriatric assessment and cognitive testing routinely done in geriatrics. MATERIAL AND METHODS: This review is based on publications retrieved by a selective search in Medline, including individual studies, meta-analyses, guidelines, Cochrane reviews, and other reviews from 1960 until August 2020. RESULTS: Awareness of sensory impairment is low among patients and health professionals working with elderly people. The evaluation of the hearing status is not always part of the geriatric assessment and not yet routinely done in psychiatric settings. However, neurocognitive testing as an important part can be strongly influenced by auditory deprivation. Misunderstanding of verbal instructions, cognitive changes, and delayed central processes may lead to a false diagnosis in up to 16% of subjects with hearing loss. To minimize this bias, several neurocognitive assessments were transformed into non-auditory versions recently, eg the most commonly used Hearing-Impaired Montreal Cognitive Assessment (HI-MoCA). However, most of them still lack normative data for elderly people with hearing loss. CONCLUSION: Hearing loss should be taken into consideration when performing geriatric assessment and cognitive testing in elderly subjects. Test batteries suitable for ARLH should be applied.

Can cochlear implantation improve neurocognition in the aging population?

INTRODUCTION: The relationship between cognition and the ability to hear is well known. Due to changes in demographics, the number of people with sensorineural hearing loss and cognitive impairment is increasing. The aim of this study was to identify the impact of hearing rehabilitation via cochlear implantation on cognitive decline among the aging population. PATIENTS AND METHODS: This prospective study included 60 subjects aged between 50 and 84 years (mean 65.8 years, SD=8.9) with a severe to profound bilateral hearing impairment. A computer-based evaluation of short- and long-term memory, processing speed, attention, working memory and inhibition was performed prior to surgery as well as 6 and 12 months after cochlear implantation. Additionally, speech perception at 65 and 80 dB (Freiburger monosyllabic speech test) as well as disease-related (Nijmegen Cochlear Implant Questionnaire) and general (WHOQOL-OLD) quality of life were assessed. RESULTS: Six months postimplantation, speech perception, quality of life and also neurocognitive abilities significantly increased. The most remarkable improvement after 6 months was detected in executive functions such as attention (p<0.001), inhibition (p=0.025) and working memory (n-back: p=0.002; operation span task: p=0.008), followed by delayed recall (p=0.03). In contrast, long-term memory showed a significant change of performance only after 12 months (p=0.021). After 6 months, most cognitive domains remained stable, except working memory assessed by the operation span task, which significantly improved between 6 and 12 months (p<0.001). No correlation was found between cognitive results and duration of deafness, speech perception or quality of life. CONCLUSION: Cochlear implantation does not only lead to better speech perception and quality of life, but has also been shown to improve cognitive skills in hearing impaired adults aged 50 years or more. These effects seem to be independent of each other.

[Computer based neurocognitive testing in audiology]. / Computerbasierte Testung neurokognitiver Aspekte im Rahmen der audiologischen Diagnostik.

INTRODUCTION: Due to the demographic changes neurocognition has become an important issue also in the field of hearing rehabilitation. BACKGROUND: The present study aimed to evaluate the feasibility of a neurocognitive test using computer based tasks with regard to the elderly with and without hearing loss and its practicability for the daily clinical ENT setting. PATIENTS: 171 patients of both genders with normal hearing or a profound hearing loss were enrolled in the study: 90 middleaged persons were between 50 and 64 years (57.0 ± 4.5 years) and 81 elderly persons 65 years and older (72.5 ± 5.4). METHOD: A set of computer-based neurocognitive tasks with only visual instructions covering attention, processing speed, short- and longterm memory as well as executive functions was applied. A presession under the supervision of a trained assistant was included. RESULTS: All patients were capable to complete the assessment by themselves regardless of age and hearing status, however the hearing impaired required 15 minutes more to finish the pretest and reported about a higher level of effort than normal hearing subjects (71 % versus 63 %). Interestingly 90 % of the older individuals claimed the test to fit with all ages, whereas 30 % of the middleaged participants remained skeptical (p = 0.02). CONCLUSION: The presented neurocognitive assessment might be a useful instrument which can be easily included into the daily clinical ENT. It may give important hints to the otolaryngologist in order to develop the most effective hearing rehabilitation strategy.

Application of a computer-based neurocognitive assessment battery in the elderly with and without hearing loss.

INTRODUCTION: Due to demographic changes, the number of people suffering not only from dementia illness but also from hearing impairment with the need for hearing rehabilitation have increased noticeably. Even with the association between hearing, age, and cognitive decline being well known, this issue has so far not played an important role in daily clinical Ear Nose Throat settings. The aim of the present study was to evaluate the use of a computer-based battery of tests of neurocognitive abilities in older patients with and without hearing loss. PATIENTS AND METHODS: A total of 120 patients aged 50 years and older were enrolled in this prospective clinical study: 40 patients suffered from severe bilateral hearing loss and were tested before cochlear implantation and 80 patients showed normal hearing thresholds between 500 and 4,000 Hz bilaterally. The test battery covered a wide range of cognitive abilities such as long- and short-term memory, working memory (WM), attention, inhibition, and other executive functions. Individuals with severe depression or cognitive impairment were excluded. RESULTS: Hearing status was a significant predictor of performance on delayed recall (P=0.0082) and verbal fluency after adjusting for age (P=0.0016). Age predominantly impacted on inhibition (P=0.0039) and processing speed (P<0.0001), whereas WM measured by the Operation Span task (OSPAN) and the attention were influenced by both age and hearing. The battery of tests was feasible and practical for testing older patients without prior computer skills. CONCLUSION: A computerized neurocognitive assessment battery may be a suitable tool for the elderly in clinical practice. While it cannot replace a thorough neuropsychological examination, it may help to draw the line between cognitive and hearing impairment in the elderly and enable the development of individual strategies for hearing rehabilitation.