[Awareness disorders in Alzheimer's disease and in mild cognitive impairment]

COVID-19 and Alzheimer's Disease: A Literature Review

There are a number of potential implications for the field of Alzheimer’s disease (AD) stemming from the global spread of “SARS-COV-2”. Many studies that were conducted by Cleveland Clinic researchers identified a link between COVID-19 infection and brain abnormalities seen in people with AD. This article explains the association between COVID-19 and AD and how people with AD are affected by COVID-19, whether directly or indirectly. First, this article begins by explaining AD and its types, then giving an overview about COVID-19, its symptoms and the associated complications. Then, direct and indirect consequences of COVID-19 on people experiencing AD are discussed briefly. Some management strategies are recommended at the end of this article in addition to a future perspective on this topic. This article concludes by summarizing the main points mentioned about the association between COVID-19 and AD.

Awareness dimensions and associated factors in Alzheimer's disease

OBJECTIVES

We recently reported the major role depression and apathy in awareness among Alzheimer patients, using the stage of the disease as an exposure factor and exploring different assessment methods. Using the same patient data, we aimed here to explore the different dimensions of awareness assessed by different sub-scales in awareness scales.

METHOD

Sixty-one Alzheimer patients were examined using four awareness scales relating to three assessment methods: (a) patient-caregiver discrepancy; (b) clinical rating; and (c) prediction of performance discrepancy. Global cognition, executive functioning, autonomy, depression and apathy were also assessed. Multivariate logistic models were performed using disease stage as an exposure factor for awareness scales and sub-scales. Correlations across the different factors and patient and caregiver awareness ratings were computed.

RESULTS

The patient-caregiver discrepancy and clinical rating methods (a, b) both identified the factors associated with awareness in the overall scales and the sub-scales as being depression and/or apathy. Depression correlated with patient self-ratings while apathy correlated with caregiver ratings. The prediction of performance discrepancy method (c) identified different factors in the overall scale, executive factors in three sub-scales involving executive domains and the memory factor in a sub-scale involving the mnesic domain.

DISCUSSION

The awareness scales using a referential based on a human rating (a, b) suggest that awareness is unidimensional, with depression impacting self-reports and apathy influencing caregiver/clinical reports. Scales based on a test rating (c) appear to be more closely associated with the dimensions assessed. This highlights the role of the reference system for awareness assessment in Alzheimer's disease.

Ecological relevance of the Iowa gambling task in patients with Alzheimer's disease and mild cognitive impairment

BACKGROUND

In spite of their extensive use, the ecological relevance of tasks dedicated to assessing real-world decision-making in a laboratory setting remains unclear.

OBJECTIVES

Our study aimed to evaluate the relationship between decision-making and behavioral competency and awareness of limitations.

METHODS

A total of 20 patients with Alzheimer's disease (AD), 20 with amnestic mild cognitive impairment (aMCI) and 20 healthy controls (HC) were assessed for decision-making using the Iowa Gambling Task (IGT). Behavioral competency was evaluated by the Patient Competency Rating Scale (PCRS), which requires each participant and a relative to answer the same 30 questions on participant's competency and to rate each item, while awareness of limitations was evaluated by subtracting the self-rated score from the relative-rated score.

RESULTS

Using the median-split approach, the proportion of disadvantageous decision-makers was higher in both the MCI and AD groups than in HC (P=0.02 and P=0.03, respectively), with no differences between clinical groups. The percentage of participants with poorer behavioral competency was also higher in the MCI and AD than in the HC (self-rated: P=0.025 and P=0.01, respectively; relative-rated: P=0.008 and P=0.008, respectively), again with no differences between MCI and AD. All groups were comparable in awareness. For all participants, disadvantageous decision-making was associated with both reduced behavioral competency and poor awareness of limitations (OR: 3.47, P=0.03 and OR: 5.4, P=0.004, respectively).

CONCLUSION

Our findings support the ecological relevance of the IGT. Behavioral competency integrity and awareness of limitations are both associated with advantageous decision-making profiles.