Struggling to make Indian Curry…. Early indication of dementia?

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The September International Psychogeriatrics Article of the Month is entitled “Discriminative power of the advanced activities of daily living (a-ADL) tool in the diagnosis of mild cognitive impairment in an older population” by P. De Vriendt, T. Mets, M. Petrovic and E. Gorus.

 

This blog post was written for us by one of the paper’s authors, Prof. Dr. Patricia De Vriendt

Struggling to make Indian Curry…. Early indication of dementia?

With a diagnosis of Alzheimer’s dementia (AD) comes an understanding that the affected individual will suffer an inevitable and progressive decline in their functional abilities. In order to identify and treat dementia as early as possible the concept of Mild Cognitive Impairment (MCI) was established. MCI is seen as the intermediate stage between normal aging and AD and is characterized by subjective and objective memory impairments in the absence of functional decline [the loss of ability to perform everyday tasks without assistance]. However, this criterion is controversial since our previous studies and also many other studies showed that mild changes in Activities of Daily Living (ADL) can be present and probably predict conversion to dementia.

The overall issue was whether an evaluation of ADL might underpin the diagnosis of MCI in a valid and reliable way, with an accuracy comparable with cognitive assessment.

For this reason, we hypothesized that an evaluation of ADL should be done on the level of “the advanced (a)-ADL”, encompassing all the most complex activities one can perform, such as using (household) technology, preparing complex dishes, driving, going on holidays, doing sports, practice hobbies, or arts, etc. The a-ADL are considered as the most difficult activities, requiring high level cognitive organization, and accordingly are most vulnerable to early cognitive decline.

We set out to study this issue by developing and validating a new advanced (a)-ADL tool, based on the International Classification of Functioning, Disability and Health framework (ICF), evaluating high-level activities. Taking each participant as their own reference, we calculated a global Disability Index (a-ADL-DI), a Cognitive Disability Index (a-ADL-CDI), and a Physical Disability Index (a-ADL-PDI), based on the number of activities performed and the severity and causes of the functional problem.

The study published as ‘paper of the month’ evaluated the discriminative power of the a-ADL tool in order to establish diagnostic accuracy.

Based upon clinical evaluation and a set of global, cognitive, mood, and functional assessments, 150 community-dwelling participants (average age 80.3 years) were included and diagnosed as (1) cognitively healthy participants (n = 50); (2) patients with a-MCI (n = 48), or (3) mild to moderate AD (n = 52). The a-ADL tool was not a part of the clinical evaluation.

The a-ADL tool was able to detect the diagnostic distinction between cognitively healthy older persons, patients with a-MCI, and patients with AD. Both the a-ADL-DI and the a-ADL-CDI – of interest in this population – showed promising results and differed significantly between the groups; in contrast, the a-ADL-PDI did not.

What is the take home message of this research?

The a-ADL tool showed a good ability to distinguish normal and pathological cognitive aging. Its discriminative power for underlying causes of limitations is an advantage. Concluding, the evaluation of a-ADL, when administered in a systematic and scientific way, enables the diagnosis of MCI and – moreover – is experienced as less invasive by the patients. In the same time, this evaluation offers directions for clinical treatment, rehabilitation, advice and coaching.

 

The full paper “Discriminative power of the advanced activities of daily living (a-ADL) tool in the diagnosis of mild cognitive impairment in an older population” is available free of charge for a limited time here.

The commentary paper “A useful development in measuring activities of daily living” by David Ames is also available free of charge here.

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Rates of diagnostic transition and cognitive change – an 18-month follow-up of the cohort from the AIBL study

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The April International Psychogeriatrics Article of the Month is entitled ‘Rates of diagnostic transition and cognitive change at 18-month follow-up among 1,112 participants in the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Ageing (AIBL)’ by Kathryn A. Ellis, Cassandra Szoeke, Ashley I. Bush et al.

The Australian Imaging, Biomarkers and Lifestyle (AIBL) Flagship Study of Ageing is a prospective study of 1,112 individuals (211 with Alzheimer’s disease (AD), 133 with mild cognitive impairment (MCI), and 768 healthy controls (HCs)).

In this paper, the authors report diagnostic and cognitive findings at the first (18-month) follow-up of the cohort. The first aim was to look at rates of transition from HC to MCI, and MCI to AD. The second aim was to characterize the cognitive profiles of individuals who transitioned to a more severe disease stage compared with those who did not.

Eighteen months after baseline, participants underwent comprehensive cognitive testing and diagnostic review, provided an 80 ml blood sample, and completed health and lifestyle questionnaires. A subgroup also underwent amyloid PET and MRI neuroimaging.

The diagnostic status of 90% of the cohorts was determined (972 were reassessed, 28 had died, and 112 did not return for reassessment). The 18-month cohort comprised 692 HCs, 82 MCI cases, 197 AD patients, and one Parkinson’s disease dementia case. The transition rate from HC to MCI was 2.5%, and cognitive decline in HCs who transitioned to MCI was greatest in memory and naming domains compared to HCs who remained stable. The transition rate from MCI to AD was 30.5%.

Cognitive decline with age is not a rapid process for most people, and 18 months is a fairly short period over which to detect emergent decline or transition to clinically diagnosable MCI or AD among previously healthy individuals. Nevertheless, the detailed cognitive data collected in the AIBL study give us the best possible opportunity of detecting such changes that, after future waves of follow-up are complete, may allow us to make a major contribution to determining factors that may be predictive of future cognitive decline in older individuals who are cognitively healthy at present.

The author of the commentary paper, John O’Brien, commented “Of particular note, the AIBL cohort predominantly focuses on the early transition from normality to cognitive impairment, as around three quarters of the participants in the cohort are healthy controls. It also provides a combination of a comprehensive and longitudinal clinical and biomarker assessment with a focus on prior lifestyle factors such as diet and exercise.

There are several extremely interesting and important observations from this study, which have relevance for all cohort studies.Clearly, the combination of clinical, cognitive, risk factor, and biomarker data from the AIBL cohort will help provide some answers to several current questions about the key factors associated with cognitive decline and the rate and temporal ordering of clinical and biomarker changes. However, challenges still remain; even cohorts as sizeable as the AIBL study are relatively limited in size (partly because of the great expense of undertaking such longitudinal deep phenotyping studies) to fully address the investigation of all interactions between environmental, genetic, and lifestyle risk factors. Increased collaborative efforts both nationally and internationally are emerging and will be essential to make future progress.

 

The full paper “Rates of diagnostic transition and cognitive change at 18-month follow-up among 1,112 participants in the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Ageing (AIBL)” is available free of charge for a  limited time here.

The commentary on the paper, “The importance of longitudinal cohort studies in understanding risk and protective factors for dementia” is also available free of charge for one month here.

 

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