A Longitudinal Evaluation of the Pattern of Social Cognition Impairment in Brazilians With Alzheimer's Disease.

BACKGROUND: Social cognition (SC) impairments contribute to the dependence of people with Alzheimer disease (AD), influencing their functional disability and the burden on family members and caregivers. Our objective was to longitudinally investigate the relationship between SC and cognitive and clinical variables in persons with AD and their caregivers. We also evaluated the different SC predictors from 3 perspectives: people with AD, caregivers of people with AD, and discrepancy analysis. METHODS: In all, 137 dyads (people with AD and their caregivers) underwent 2 assessments: at baseline (M1) and after 1 year (M2). During follow-up, 58 dyads were excluded, and the study was thus concluded with 79. RESULTS: Longitudinal analysis of the people with AD showed that while some cognitive functions declined (which is consistent with disease progression), SC impairments showed a more stable pattern. Another interesting result was related to SC predictors. For people with AD, SC was associated with cognition at both time points. For caregivers, besides cognition, other predictors included reduced functional abilities and quality of life in people with AD. These results are consistent with the discrepancy predictors. CONCLUSION: The stable pattern in SC functioning over 12 months in AD suggests that this neurocognitive domain may be influenced more by emotional processing than by cognitive impairment. In addition, the SC predictors showed that the investigation of different points of view enables a more global understanding, contributing to better and more targeted treatment for the patient.

The relationship between theory of mind and cognition in Alzheimer's disease: A systematic review.

Introduction: Theory of Mind (ToM) refers to an individual's ability to attribute mental states to others. It is well established that the behavioral variant of frontotemporal dementia can undermine ToM. However, there is no consensus on how Alzheimer's disease affects ToM. The following report represents a systematic literature review of ToM in Alzheimer's disease over the past ten years.Method: We performed a survey using the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) criteria. The literature search was performed using the electronic databases MEDLINE (Pubmed) and Science Citation Index (ISI). The following descriptors were used in the review process: theory of mind or mentalizing and Alzheimer disease or Alzheimer's disease or Alzheimer type dementia. This systematic review was recorded in the International Prospective Register of Systematic Reviews (PROSPERO) under the number CDR42018115152.Results: We identified 117 articles, 24 of which met our criteria. The most common assessment measure used in the evaluation of the ToM was the first and second order false belief task. Many studies reported that individuals with Alzheimer's disease were impaired on more complex tasks, such as second-order false belief tasks, but had intact performance on simpler tasks, such as first order false beliefs and affective ToM. In contrast, some studies reported that ToM deficits may also appears in simpler and affective tasks.Conclusions: The variability in methodologies, the design and complexity of the tasks applied, the heterogeneity in terms of dementia stage/severity, and the level of cognitive impairment contribute to the variability and inconsistency of the results. Future research should investigate the ToM using more ecological and standardized methods.

Facial expression recognition in Alzheimer's disease: A systematic review.

Introduction: It is well established that behavioral variant frontotemporal dementia can impair social and emotional function. However, there is no consensus regarding how Alzheimer's disease can affect facial expression recognition. We aim to systematically review all the literature addressing this issue over the last 10 years. Method: We conducted a search based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search for literature was undertaken on 19 September 2017, using Pubmed, SciELO, BIREME, and Thomson Reuters Web of Science electronic databases. The key terms for the search were: Alzheimer's disease, dementia, and facial expression recognition.Results: We screened 173 articles, and 22 of them were selected. The most common methodology involved showing participants photographs of people expressing the six basic emotions-fear, anger, sadness, disgust, surprise, and happiness. Results were ambiguous. Among people with mild Alzheimer's disease, happiness was easier to recognize than the other five basic emotions, with sadness and anger the most difficult to recognize. In addition, the intensity level of the emotions presented seems to be important, and facial expression recognition is related to specific cognitive capacities, including executive function and visuoperceptual abilities. Impairment in facial expression recognition does not appear to be a consistent neuropsychological finding in Alzheimer's disease. Conclusions: The lack of standardized assessment instruments and the heterogeneity of the methods and samples used across studies hamper comparisons. Future researches should investigate facial expression recognition through more ecological and standardized methods.