The impact of mild cognitive impairment on functional abilities in the elderly

Is hospitalization a risk factor for cognitive decline in older age adults?

OBJECTIVES

Many studies document cognitive decline following specific types of acute illness hospitalizations (AIH) such as surgery, critical care, or those complicated by delirium. However, cognitive decline may be a complication following all types of AIH. This systematic review will summarize longitudinal observational studies documenting cognitive changes following AIH in the majority admitted population and conduct meta-analysis (MA) to assess the quantitative effect of AIH on post-hospitalization cognitive decline (PHCD).

METHODS

We followed Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Selection criteria were defined to identify studies of older age adults exposed to AIH with cognitive measures. 6566 titles were screened. 46 reports were reviewed qualitatively, of which seven contributed data to the MA. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

The qualitative review suggested increased cognitive decline following AIH, but several reports were particularly vulnerable to bias. Domain-specific outcomes following AIH included declines in memory and processing speed. Increasing age and the severity of illness were the most consistent risk factors for PHCD. PHCD was supported by MA of seven eligible studies with 41,453 participants (Cohen's d = -0.25, 95% CI [-0.02, -0.49] I² 35%).

CONCLUSIONS

There is preliminary evidence that AIH exposure accelerates or triggers cognitive decline in the elderly patient. PHCD reported in specific contexts could be subsets of a larger phenomenon and caused by overlapping mechanisms. Future research must clarify the trajectory, clinical significance, and etiology of PHCD: a priority in the face of an aging population with increasing rates of both cognitive impairment and hospitalization.

Fruit and Vegetable Consumption and Cognitive Disorders in Older Adults: A Meta-Analysis of Observational Studies

Objectives

The aim of this meta-analysis was to assess the quantitative associations between fruit and vegetable intake and cognitive disorders in older adults.

Design

A meta-analysis.

Setting and Participants

We used the PubMed, Web of Science and Scopus databases for a literature search to 12 April 2022. We preliminarily retrieved 11,759 studies, 16 of which met the inclusion criteria including six cross-sectional studies, nine cohort studies and one case-control study, incorporating 64,348 participants and 9,879 cases.

Methods

Using the three databases, we identified observational studies exploring the association. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random effects model.

Results

Sixteen studies were included in the meta-analysis, and the results showed that increased fruit and vegetable consumption in older adults was associated with a decline in the prevalence of cognitive disorders (OR: 0.79, 95% CI: 0.76–0.83). Moreover, intake of fruits (OR: 0.83, 95% CI: 0.77–0.89) and vegetables (OR: 0.75, 95% CI: 0.70–0.80) alone were both associated with a lower prevalence of cognitive disorders. Subgroup analyses indicated that the intake of fruits and vegetables was associated with the prevalence of cognitive impairment (OR: 0.72, 95% CI: 0.76–0.80) and dementia (OR: 0.84, 95% CI: 0.78–0.91) but not Alzheimer’s disease (OR: 0.88, 95% CI: 0.76–1.01).

Conclusion and Implications

Our meta-analysis provides evidence that the intake of fruits and vegetables is inversely proportional and linearly associated with the prevalence of cognitive disorders in older adults. Future research is required to further investigate the preventive effects of the frequency, quantity, and duration of eating vegetables and fruits on cognitive disorders in older adults.

The Usefulness of Evaluating Performance of Activities in Daily Living in the Diagnosis of Mild Cognitive Disorders

The Assessment of Activities of Daily Living (ADL) is paramount to ensure the accurate early diagnosis of neurocognitive disorders. Unfortunately, the most common ADL tools are limited in their use in a diagnostic process. Hence, we set out to validate a tool to evaluate basic (b-), instrumental (i-), and advanced (a-) ADL called the Brussels Integrated Activities of Daily Living Inventory (BIA). At the geriatric day hospital of the University Hospital Brussels (Belgium) older persons (65+) labelled as Cognitively Healthy Persons (CHP) (n = 47), having a Mild Cognitive Impairment (MCI) (n = 39), and having Alzheimer's disease (AD) (n = 44) underwent a diagnostic procedure for neurocognitive disorders. Additionally, the BIA was carried out. An exploration using both (cumulative) logistic regressions and conditional inference trees aimed to select the most informative scales to discriminate between the HCP, persons with MCI and AD. The distinction between CHP and MCI and between MCI and AD was moderately successful with the i-ADLs, in addition to age. Therefore, it is advisable to conduct a multidomain assessment in which the i-ADL could serve as non-invasive and non-time-consuming screening, while the BIA might be useful for diagnostics and disease management.

Performance-Based vs Informant-Reported Instrumental Activities of Daily Living in Predicting Dementia

OBJECTIVES

Identifying individuals at risk of developing dementia may be aided by early detection of functional impairments. The aims of the present study were to examine differences in informant-reported and performance-based measures of instrumental activities of daily living (IADL) and to assess whether a performance-based IADL measure contributes additional unique variance over informant reports in predicting incident dementia over 4 years.

DESIGN

Prospective cohort study (Sydney Memory and Ageing Study).

SETTING

Eastern Suburbs, Sydney, Australia.

PARTICIPANTS

307 community-dwelling individuals (60.6% female) aged between 76 and 96 years with normal cognition (NC; n = 190) or mild cognitive impairment (MCI; n = 117).

METHODS

IADL ability was assessed with the performance-based Sydney Test of Activities of Daily Living in Memory Disorders (STAM) and the Bayer-Activities of Daily Living (B-ADL) informant report, at baseline and 4-year follow-up. Covariates included age, sex, education, Mini-Mental State Examination and Geriatric Depression Scale scores, arthritis, vision impairment, cardiovascular risk, and number of medications. Logistic regressions were conducted to examine the longitudinal association between the 2 types of IADL measures and incident dementia.

RESULTS

Logistic regressions showed that performance-based IADL impairment at baseline [odds ratio (OR) = 0.83, 95% confidence interval (CI) 0.77, 0.90; P < .001] and decline in performance-based IADL function (OR = 0.82, 95% CI 0.73, 0.91; P < .001) were associated with incident dementia over 4 years, with the association provided by the STAM being statistically significant over and above the B-ADL.

CONCLUSIONS AND IMPLICATIONS

Performance-based measures of IADL can predict progression to dementia over 4 years beyond that provided by an informant report of IADL. Performance-based IADL measures are promising tools for clinical practice to identify individuals at greater risk of developing dementia.

Predicting functional decline in older emergency patients-the Safe Elderly Emergency Discharge (SEED) project

Objective

to profile the trajectory of, and risk factors for, functional decline in older patients in the 30 days following Emergency Department (ED) discharge.

Methods

prospective cohort study of community-dwelling patients aged ≥65 years, discharged home from a metropolitan Melbourne ED, 31 July 2012 to 30 November 2013. The primary outcome was functional decline, comprising either increased dependency in personal activities of daily living (ADL) or in skills required for living independently instrumental ADL (IADL), deterioration in cognitive function, nursing home admission or death. Univariate analyses were used to select risk factors and logistic regression models constructed to predict functional decline.

Results

at 30 days, 34.4% experienced functional decline; with 16.7% becoming more dependent in personal ADL, 17.5% more dependant in IADL and 18.4% suffering deterioration in cognitive function. Factors independently associated with decline were functional impairment prior to the visit in personal ADL (Odds Ratio [OR] 3.21, 95% confidence interval [CI] 2.26-4.53) or in IADL (OR 6.69, 95% CI 4.31-10.38). The relative odds were less for patients with moderately impaired cognition relative to those with normal cognition (OR 0.38, 95% CI 0.19-0.75). There was a 68% decline in the relative odds of functional decline for those with any impairment in IADL who used an aid for mobility (OR 0.32, 95% CI 0.14-0.7).

Conclusion

older people with pre-existing ADL impairment were at high risk of functional decline in the 30 days following ED presentation. This effect was largely mitigated for those who used a mobility aid. Early intervention with functional assessments and appropriate implementation of support services and mobility aids could reduce functional decline after discharge.

Subjective Cognitive Decline from a Phenomenological Perspective: A Review of the Qualitative Literature

BACKGROUND

Subjective cognitive decline is related to greater risk of dementia and biological markers of Alzheimer's disease (AD), but researchers are yet to characterize the phenomenological perspective of cognitive decline in those with and without a diagnosis of AD.

OBJECTIVE

To collate and synthesize studies measuring the subjective experience of cognitive change or decline in healthy older adults and those with mild cognitive impairment and AD.

METHODS

We reviewed 58 peer-reviewed articles that were found to directly or indirectly refer to the subjective experience of cognitive decline.

RESULTS

We extracted eight central themes, dealing with cognitive changes experienced by each diagnostic group, and also related to issues of changing self-identity, the causal attribution of cognitive decline, the anxiety and concern related to perceived decline, the negative perceptions attached to a diagnosis of dementia, changing levels of insight, and perception of well-being in aging.

CONCLUSION

This review is the first step toward characterizing phenomenological profiles of cognitive change in both non-demented and demented older adults. Developing a clearer understanding of subjective cognitive decline, particularly at the earliest stages of AD, will augment the sensitivity of detection of individuals at greater risk of future dementia.

Effects of β-hydroxy-β-methyl butyrate on working memory and cognitive flexibility in an animal model of aging

OBJECTIVES

Normal aging results in cognitive decline and nutritional interventions have been suggested as potential approaches for mitigating these deficits. Here, we used rats to investigate the effects of short- and long-term dietary supplementation with the leucine metabolite β-hydroxy-β-methyl butyrate (HMB) on working memory and cognitive flexibility.

METHODS

Beginning ∼12 months of age, male and female Long-Evans rats were given twice daily access to sipper tubes containing calcium HMB (450 mg/kg) or vehicle (285 mg/kg calcium lactate) in a sucrose solution (20% w/v). Supplementation continued for 1 or 7 months (middle- and old-age (OA) groups, respectively) before testing began. Working memory was assessed by requiring rats to respond on a previously sampled lever following various delays. Cognitive flexibility was assessed by training rats to earn food according to a visual strategy and then, once acquired, shifting to an egocentric response strategy.

RESULTS

Treatment with HMB improved working memory performance in middle-age (MA) males and OA rats of both sexes. In the cognitive flexibility task, there was a significant age-dependent deficit in acquisition of the visual strategy that was not apparent in OA males treated with HMB. Furthermore, HMB ameliorated an apparent deficit in visual strategy acquisition in MA females.

DISCUSSION

Together, these findings suggest that daily nutritional supplementation with HMB facilitates learning and improves working memory performance. As such, HMB supplementation may mitigate age-related cognitive deficits and may therefore be an effective tool to combat this undesirable feature of the aging process.

A 36-month follow-up of decline in activities of daily living in individuals receiving domiciliary care

Background

There have been few studies of how personal and instrumental activities of daily living (P-ADL and I-ADL) develop over time in older people receiving domiciliary care. This study aimed at assessing variables associated with the development of P-ADL and I-ADL functioning over a 36-month follow-up period, with a particular focus on cognitive functioning.

Method

In all, 1001 older people (≥70 years) receiving domiciliary care were included in a longitudinal study with three assessments of P-ADL and I-ADL functioning during 36 months. P-ADL and I-ADL were assessed using the Lawton and Brody’s Physical Self-Maintenance Scale and Instrumental Activities of Daily Living Scale, respectively. Mini Mental State Examination (MMSE), diagnosis of dementia and MCI, neuropsychiatric symptoms and use of psychotropic medication were also evaluated during the three assessments. Baseline demographic and general medical health information and information of being a nursing home resident at follow-up were recorded. Linear mixed models were estimated.

Results

There was a significant decline in P-ADL and I-ADL functioning throughout the follow-up. A lower MMSE sum-score, diagnosed MCI and dementia, a higher level of neuropsychiatric symptoms and the use of antipsychotics and antidepressants recorded at each assessment were associated with a decline in both P-ADL and I-ADL functioning. Furthermore, a decline in P-ADL and I-ADL functioning at follow-ups was associated with being male, a higher baseline age and in poorer medical health as well as residing in a nursing home at follow-up.

Conclusion

P-ADL and I-ADL functioning in older people worsened over time. The worsening was associated with lower MMSE sum-score, diagnosed MCI and dementia, poorer medical health, neuropsychiatric symptoms, use of psychotropic medication and being transferred to nursing home care. Clinicians should pay close attention to the assessment and treatment of these factors to help older people maintain their level of functioning for as long as possible.

The Potential Utility of Eye Movements in the Detection and Characterization of Everyday Functional Difficulties in Mild Cognitive Impairment

Mild cognitive impairment (MCI) refers to the intermediate period between the typical cognitive decline of normal aging and more severe decline associated with dementia, and it is associated with greater risk for progression to dementia. Research has suggested that functional abilities are compromised in MCI, but the degree of impairment and underlying mechanisms remain poorly understood. The development of sensitive measures to assess subtle functional decline poses a major challenge for characterizing functional limitations in MCI. Eye-tracking methodology has been used to describe visual processes in everyday, naturalistic action among healthy older adults as well as several case studies of severely impaired individuals, and it has successfully differentiated healthy older adults from those with MCI on specific visual tasks. These studies highlight the promise of eye-tracking technology as a method to characterize subtle functional decline in MCI. However, to date no studies have examined visual behaviors during completion of naturalistic tasks in MCI. This review describes the current understanding of functional ability in MCI, summarizes findings of eye-tracking studies in healthy individuals, severe impairment, and MCI, and presents future research directions to aid with early identification and prevention of functional decline in disorders of aging.

Greater body mass index is associated with poorer cognitive functioning in male heart failure patients

BACKGROUND

Heart failure (HF) and obesity are associated with cognitive impairment. However, few studies have investigated the relationship between adiposity and cognitive functioning in HF for each sex, despite observed sex differences in HF prognosis. We tested the hypothesis that greater body mass index (BMI) would be associated with poorer cognitive functioning, especially in men, in sex-stratified analyses.

METHODS AND RESULTS

Participants were 231 HF patients (34% female, 24% nonwhite, average age 68.7 ± 7.3 years). Height and weight were used to compute BMI. A neuropsychology battery tested global cognitive function, memory, attention, and executive function. Composites were created using averages of age-adjusted scaled scores. Regressions adjusting for demographic and medical factors were conducted. The sample was predominantly overweight/obese (76.2%). For men, greater BMI predicted poorer attention (ΔR(2) = 0.03; β = -0.18; P = .01) and executive function (ΔR(2) = 0.02; β = -0.13; P = .04); these effects were largely driven by men with severe obesity (BMI ≥40 kg/m(2)). BMI did not predict memory (P = .69) or global cognitive functioning (P = .08). In women, greater BMI was not associated with any cognitive variable (all P ≥ .09).

DISCUSSION

Higher BMI was associated with poorer attention and executive function in male HF patients, especially those with severe obesity. These patients may therefore have more difficulties with the HF treatment regimen and may have poorer outcomes.

Cognitive decline one year after hospitalization in older adults without dementia

BACKGROUND/AIMS

We studied cognitive functioning 1 year after hospitalization (T2) in patients at least 65 years old without cognitive impairment at baseline (T1).

METHODS

Cognition was assessed using the Mini-Mental State Examination (MMSE) at both time points. We included 211 (114 women) patients with a mean age of 78.3 (SD 7.0) years and an MMSE score of 24 and above.

RESULTS

At T2, 69 (32.7%) patients had an MMSE score below 24. In participants with MMSE 24-26 at T1, cognitive decline was related to impaired physical self-maintenance, a decline in the performance of the instrumental activities of daily living, impaired hearing and less reading ability. In participants with MMSE 27-30, cognitive decline was associated with higher comorbidity (Charlson Index) and impaired physical self-maintenance and hearing.

CONCLUSION

A reduced functioning level and increased comorbidity predicted a decline in cognitive functioning.

The Judgment Test of the Neuropsychological Assessment Battery (NAB): psychometric considerations in an assisted-living sample

A total of 82 older adults recruited from assisted-living facilities completed the Judgment subtest of the Neuropsychological Assessment Battery. The internal consistency reliability of Judgment scores in this sample, as estimated by Cronbach's α, was .83. Significant and strong Judgment score correlations with measures of general cognitive functioning and instrumental activities of daily living provided evidence of construct validity. Furthermore, participants who exhibited the capacity to consent to the evaluation performed significantly better on the Judgment subtest than did participants who did not exhibit consent capacity. Finally, Judgment scores predicted a significant proportion of variance in both instrumental and basic activities of daily living over and above the variance accounted for by scores on measures of general cognitive functioning and executive functioning. This study presents promising preliminary evidence of the incremental validity of Judgment subtest scores for predicting both basic and instrumental activities of daily living in an assisted-living sample.

Information and communication technology to support self-management of patients with mild acquired cognitive impairments: systematic review

Background

Mild acquired cognitive impairment (MACI) is a new term used to describe a subgroup of patients with mild cognitive impairment (MCI) who are expected to reach a stable cognitive level over time. This patient group is generally young and have acquired MCI from a head injury or mild stroke. Although the past decade has seen a large amount of research on how to use information and communication technology (ICT) to support self-management of patients with chronic diseases, MACI has not received much attention. Therefore, there is a lack of information about what tools have been created and evaluated that are suitable for self-management of MACI patients, and a lack of clear direction on how best to proceed with ICT tools to support self-management of MACI patients.

Objective

This paper aims to provide direction for further research and development of tools that can support health care professionals in assisting MACI patients with self-management. An overview of studies reporting on the design and/or evaluation of ICT tools for assisting MACI patients in self-management is presented. We also analyze the evidence of benefit provided by these tools, and how their functionality matches MACI patients’ needs to determine areas of interest for further research and development.

Methods

A review of the existing literature about available assistive ICT tools for MACI patients was conducted using 8 different medical, scientific, engineering, and physiotherapy library databases. The functionality of tools was analyzed using an analytical framework based on the International Classification of Functioning, Disability and Health (ICF) and a subset of common and important problems for patients with MACI created by MACI experts in Sweden.

Results

A total of 55 search phrases applied in the 8 databases returned 5969 articles. After review, 7 articles met the inclusion criteria. Most articles reported case reports and exploratory research. Out of the 7 articles, 4 (57%) studies had less than 10 participants, 5 (71%) technologies were memory aids, and 6 studies were mobile technologies. All 7 studies fit the profile for patients with MACI as described by our analytical framework. However, several areas in the framework important for meeting patient needs were not covered by the functionality in any of the ICT tools.

Conclusions

This study shows a lack of ICT tools developed and evaluated for supporting self-management of MACI patients. Our analytical framework was a valuable tool for providing an overview of how the functionality of these tools matched patient needs. There are a number of important areas for MACI patients that are not covered by the functionality of existing tools, such as support for interpersonal interactions and relationships. Further research on ICT tools to support self-management for patients with MACI is needed.

Detection of activity limitations in older adults with MCI or Alzheimer's disease through evaluation of perceived difficulty in use of everyday technology: a replication study

OBJECTIVES AND METHODS

Earlier research indicates that the ability to use everyday technology (ET) may be sensitive to subtle functional change. People with mild cognitive impairment (MCI) have been identified as significantly more disabled in ET use compared to controls, albeit less disabled than people with dementia. The aim of this study was to investigate the replicability of these findings using an improved version of the Everyday Technology Use Questionnaire (ETUQ) to compare perceptions of relevance and difficulty in ET use in participants with MCI or Alzheimer's disease (AD) and controls. Additional aims were to explore the validity of ETUQ, and the relationships between perceived difficulty in ET use and cognitive status, mood state, and involvement in everyday life activities. In total, 118 participants were included, 37 with AD, 37 with MCI, and 44 controls.

RESULTS

Analyses confirmed that the rating scale of the ETUQ functioned well. The three groups overlapped but differed significantly in their perceptions of ETs relevance (p < 0.05) as well as of difficulties in ET use (p < 0.001). Moderate correlations were also found between ETUQ measures and cognitive status, mood, and involvement in activities, the strongest being that between ETUQ measures and involvement in activities (r = 0.563).

CONCLUSION

Taken together, the findings underscore the plausibility of disability already in people with MCI, as the use of ET strongly correlates to involvement in activities. It is therefore important that professionals who meet older adults with cognitive impairment take this aspect of function into account in assessments and targeted interventions.

Factors associated with life-space in older adults with amnestic mild cognitive impairment

AIM

Restriction of life-space is associated with physical performance and functional decline in older adults. Little is known about the factors associated with life-space in older adults with amnestic mild cognitive impairment (aMCI). The purpose of this study was to identify factors associated with life-space in older adults with aMCI.

METHODS

The study participants were 69 older adults (mean age 74.5 years, males 56.5%) who were identified with aMCI. Life-space mobility was measured using a Japanese translation of the life-space assessment (LSA). Age, sex, cognitive function (general function, executive function and processing speed), physical performance, instrumental activities of daily living status (IADL) and fear of falling (FoF) were measured as potential relevant factors.

RESULTS

Univariate analysis showed that the LSA was associated with FoF, sex, physical performance, processing speed and IADL. In the stepwise regression analysis, FoF, processing speed and IADL maintained a significant association with the LSA scores, although sex and physical performance did not reach significance.

CONCLUSION

The results suggest that the restrictions of life-space in older adults with aMCI were more affected by the FoF, slower processing speed and restricted IADL than sex or physical performance.

Depression, cognition, and self-appraisal of functional abilities in HIV: an examination of subjective appraisal versus objective performance

Depression frequently co-occurs with HIV infection and can result in self-reported overestimates of cognitive deficits. Conversely, genuine cognitive dysfunction can lead to an under-appreciation of cognitive deficits. The degree to which depression and cognition influence self-report of capacity for instrumental activities of daily living (IADLs) requires further investigation. This study examined the effects of depression and cognitive deficits on self-appraisal of functional competence among 107 HIV-infected adults. As hypothesized, higher levels of depression were found among those who over-reported problems in medication management, driving, and cognition when compared to those who under-reported or provided accurate self-assessments. In contrast, genuine cognitive dysfunction was predictive of under-reporting of functional deficits. Together, these results suggest that over-reliance on self-reported functional status poses risk for error when diagnoses require documentation of both cognitive impairment and associated functional disability in everyday life.

Functional evaluation distinguishes MCI patients from healthy elderly people--the ADCS/MCI/ADL scale

Patients with MCI may present minor impairments in activities of daily living (ADL). The main objective of this work was to evaluate the ability of two versions of the Alzheimer's Disease Cooperative Study/Activities of Daily Living scale adapted for MCI patients (ADCS/MCI/ADL18 and ADCS/MCI/ADL24) to distinguish patients with MCI from healthy control subjects. Participants were 60 years or older and community dwelling: 31 control subjects, 30 aMCI patients and 33 AD patients. A protocol of neuropsychological tests, global evaluation scales, functional scales, and depressive symptoms assessment was used. Activities of balancing the cheque book, using a telephone, going shopping, taking medication regularly, finding objects, talking about current events, watching television, initiating complex activities, keeping appointments or meetings, reading, getting around outside the home and driving a car were impaired in aMCI patients. The ADCS/MCI/ADL24 scale was better than the ADCS/MCI/ADL18 scale in distinguishing aMCI patients from healthy controls (sensitivity=0.87, specificity=0.87, ROC c=0.887, cut-off point=52/53). The detection of initial functional changes with appropriate scales may contribute to the early diagnosis of MCI and the development of targeted interventions to improve everyday function or prolong independence.

Everyday functioning in mild cognitive impairment and its relationship with executive cognition

OBJECTIVE

Elderly persons with mild cognitive impairment (MCI) are at increased risk of dementia and functional impairments. The present study investigated the contribution of three domains of executive cognition to everyday functioning among persons with MCI.

METHODS

124 MCI patients and 68 cognitively normal elderly participants were administered a cognitive screening battery. These tests were used to divide patients into four subgroups (amnestic single domain, amnestic multiple domain, non-amnestic single domain, and non-amnestic multiple domain). Subjects were then administered 18 executive function tests that assess planning/problem-solving, working memory, and judgment. Performance of everyday activities and everyday cognition was rated with two informant-reported measures.

RESULTS

All MCI subtypes had more difficulties in everyday activities than cognitively normal elderly participants. Multiple domain MCI patients had more functional impairments than single domain MCI patients. Contrary to our expectations, only one executive function component, working memory, contributed significantly to functional status after controlling for demographic, health-related and other cognitive factors.

CONCLUSIONS

Functional abilities are compromised in all MCI subtypes. Working memory may be associated with functional impairments, but general cognitive measures account for more unique variance.

Awareness of functional difficulties in mild cognitive impairment: a multidomain assessment approach

OBJECTIVES

To determine whether patients with mild cognitive impairment (MCI) are fully aware of and provide reliable estimates of their functional status.

DESIGN

Controlled, matched-samples, cross-sectional study.

SETTING

University medical and research centers.

PARTICIPANTS

Fifty-seven persons with amnestic MCI and 68 normal controls.

MEASUREMENTS

The study examined accuracy of self-report in MCI across five functional domains (driving, financial abilities, medication management, grocery shopping, and telephone use) by comparing patients' report of functioning with their performance on laboratory-based measures of function.

RESULTS

The discrepancy between self-report and objective performance was significantly higher in patients with MCI than in their cognitively normal peers only on financial abilities. Patients with MCI overestimated their abilities on this functional domain. Patients with MCI also tended to overestimate their driving abilities, although this was not statistically significant.

CONCLUSION

These findings provide evidence that awareness of functional difficulties is not a unitary construct; rather, it varies across functional domains. They also suggest that self-report of functional abilities in MCI may be, on the whole, as accurate as in cognitively intact older adults. Even so, the self-objective discrepancies noted for both study groups suggest that supplementing self-reported information with objective functional assessment might improve detection of older adults who have begun to experience more functional restriction than is normal for age. In turn, timely identification would permit the targeted implementation of interventions that delay or forestall further deterioration in function.

Decline in verbal memory in non-demented older adults

Decline in memory function was detected in 30% of healthy community-dwelling elderly over 6 years using a task assessing delayed word list recall. Individuals with memory decline over time also demonstrated relative deficits on additional tasks of memory and learning, a task of working memory and executive function, and on a verbal (category) fluency task at their most recent assessment. These relative deficits in the performance of individuals with memory decline cannot be explained by age-related changes, education, intelligence, mood, health-related factors, or the individuals' APOE epsilon 4 status. Decline in memory performance did not result in greater complaints of cognitive difficulties when compared with normal elderly, nor did it limit overall participation in life activities. Although the significance of memory decline in the current study was not determined quantitatively, memory decline is consistent with the early deterioration characteristic of mild cognitive impairment and preclinical Alzheimer's disease and confirms the need to monitor individuals with objective memory decline, even when these individuals fall within normal limits for a given neuropsychological task.

The impact of cognitive functioning on mortality and the development of functional disability in older adults with diabetes: the second longitudinal study on aging

Background

For older adults without diabetes, cognitive functioning has been implicated as a predictor of death and functional disability for older adults and those with mild to severe cognitive impairment. However, little is known about the relationship between cognition functioning on mortality and the development of functional disability in late life for persons with diabetes. We examined the relative contribution of cognitive functioning to mortality and functional disability over a 2-year period in a sample of nationally representative older US adults with diabetes who were free from cognitive impairment through secondary data analyses of the Second Longitudinal Study of Aging (LSOA II).

Methods

Participants included 559 US adults (232 males and 327 females) ≥ 70 years old who had diabetes and who were free from cognitive impairment were examined using an adapted Telephone Interview of Cognitive Status (TICS), Activities of Daily Living (ADL), and Instrumental Activities of Daily Living (IADL).

Results

Multivariate logistic regression was conducted to investigate the independent contribution of cognitive functioning to three mutually exclusive outcomes of death and two measures of functional disability status. The covariates included in the model were participants' sex, age, race, marital status, educational level, duration of diabetes, cardiovascular disease (CVD) status, and self-rated health. Persons with diabetes who had the lowest levels of cognitive functioning relative to the highest level of cognitive functioning had a greater odds of dying (AOR = 0.80, 95% CI = 0.67–0.96) or becoming disabled (AOR = 0.87, 95% CI = 0.78–0.97) compared to those people who were disability free.

Conclusion

Older adults with diabetes and low normal levels of cognition, yet within normal ranges, were approximately 20% more likely to die and 13% more likely to become disabled than those with higher levels of cognitive functioning over a 2-year period. Brief screening measures of cognitive functioning could be used to identify older adults with diabetes who are at increased risk for mortality and functional disability, as well as those who may benefit from interventions to prevent or minimize further disablement and declines in cognitive functioning.

Cognitive, extrapyramidal, and magnetic resonance imaging predictors of functional impairment in nondemented older community dwellers: the Sydney Older Person Study

OBJECTIVES

To identify the clinical correlates of functional incapacity in the community living "old-old."

DESIGN

Cross-sectional.

SETTING

Community-based.

PARTICIPANTS

One hundred six nondemented people aged 80 to 94.

MEASUREMENTS

Participants were medically and cognitively assessed, underwent magnetic resonance imaging scanning (MRI), and were interviewed regarding their functional status: activities of daily living (ADLs), instrumental ADLs (IADLs), and the complex IADL functions of reading, hobbies, and socializing.

RESULTS

Dependency in IADLs, but not ADLs, was present. After controlling for age, sex, and education, extrapyramidal (EP) signs were significantly associated with two of the three IADLs, with EP signs comprising a composite score of 10 EP signs (e.g., resting tremor) and a 5-meter timed walk. Cognitive test performance on a range of tests was also associated with functional status. A hierarchical model confirmed the association between the EP signs and cognitive test performance and functional scores, but no "pattern" of cognitive association emerged. Hippocampal volume was associated with socializing.

CONCLUSION

This study has shown that many nondemented very old people living in the community are losing capacity to perform IADL functions and that areas of incapacity are associated with the presence of EP signs and impaired cognition. These results highlight the need for health workers to include an assessment of EP and cognitive status in their evaluation of older persons living in the community, even in the context of a lack of dementia diagnosis. Furthermore, it signifies the need to directly evaluate IADL function to identify need for intervention and support if required. This group of old-old individuals may now be considered the "survivors" of their cohort, and early detection of the difficulties they are experiencing will enable clinicians to respond appropriately, thus providing them a higher quality of life for their years to come.

Mild memory impairment in healthy older adults is distinct from normal aging

Mild memory impairment was detected in 28% of a sample of healthy community-dwelling older adults using the delayed recall trial of a word list learning task. Statistical analysis revealed that individuals with memory impairment also demonstrated relative deficits on other measures of memory, and tests of executive function, processing speed and global cognition, as measured by the CERAD and CogState batteries and CANTAB paired associate learning task. These relative deficits cannot be explained by age-related changes, education, intelligence, mood, health-related factors, or the individuals' ApoEepsilon4 status. Memory-impaired individuals (n = 30) did not recognize the extent of their memory and cognitive difficulties beyond the general complaints expressed by normal elderly (n = 77) within the study and their apparent difficulties did not appear to impact on their participation in life activities. These findings suggest it is unlikely that the memory and cognitive difficulties demonstrated by individuals with mild memory impairment reflect normal aging. Rather it is possible that such impairment may signal early neurodegenerative processes worthy of further investigation.

Mild cognitive impairment in Parkinson's disease: the challenge and the promise

This review addresses the literature surrounding Parkinson's disease (PD) and mild cognitive impairment (MCI). It discusses the neuropsychological, pharmaceutical, and pathological overlap, the socioeconomic impact of PD and MCI, and the value of recognizing, understanding, and treating MCI in PD. It is concluded from this review that MCI in PD does exist and should be considered in clinical and research investigations. Due to the lack of accepted clinical criteria, an inclusive operating definition of MCI in PD is proposed. Research guidelines for studying the presence of MCI in PD and evaluating the efficacy of pharmaceutical interventions are also suggested.

Memory impairment, but not cerebrovascular disease, predicts progression of MCI to dementia

BACKGROUND

Mild cognitive impairment (MCI) is widely viewed as the transition phase between normal aging and Alzheimer disease (AD). Given that MCI can also result from cerebrovascular disease (CVD), the authors used clinical, MRI, and cognitive measures of AD and CVD to test the hypothesis that CVD increases the likelihood of progression from MCI to dementia within 3 years.

OBJECTIVE

To examine the impact of CVD on progression of MCI to dementia.

METHODS

Fifty-two consecutive patients with MCI (71% men) including many with symptomatic CVD were longitudinally evaluated for 3.1 +/- 1.3 years. MCI was defined as a Clinical Dementia Rating Scale (CDR) score of 0.5. Dementia was defined as progression to a CDR score of > or =1.0.

RESULTS

Forty-four percent of the MCI patients had MRI infarcts, 50% of which were symptomatic. Thirty-three percent of patients progressed to dementia, and 37.8% of these had MRI infarcts. Clinically probable or possible AD was diagnosed in approximately 82% of converters. Of the clinical and MRI measures, only hippocampal volume was associated with increased risk to progression (hazard ratio [HR] = 0.31 [95% CI 0.1 to 0.92], p = 0.03). When neuropsychological measures were included in the analysis, memory (HR = 0.90 [95% CI 0.84 to 0.96], p = 0.002) and executive function (HR = 0.96 [95% CI 0.92 to 1.0], p = 0.045) were associated with increased risk of dementia progression, whereas APOE genotype, cerebrovascular risk factors, clinical stroke, presence or absence of lacunes, and extent of white matter hyperintensities did not predict progression.

CONCLUSION

Within a heterogenous group of MCI patients, including many with clinically significant CVD, baseline memory and executive performance significantly predicted likelihood to develop dementia.

Mild cognitive impairment: prevalence, prognosis, aetiology, and treatment

Mild cognitive impairment (MCI) is a recently described syndrome that is currently thought of as a transition phase between healthy cognitive ageing and dementia. Although this notion seems to be reasonable, the general nature of the term MCI--including its many definitions--makes accurate accounting of the prevalence, prognosis, and potential benefit from treatment somewhat difficult. The differences in cognitive profile and clinical progression among individuals with MCI are generally recognised. However, recent evidence also suggests that the aetiological heterogeneity among individuals with MCI could be greater than previously reported. For example, cerebrovascular disease seems to be underestimated as a potential cause of MCI. In this review, I attempt to recognise workable definitions of MCI to discuss the prevalence, pathophysiology, prognosis, and possibilities for treatment of this disorder.