Fenótipos cognitivos e perfil funcional de pacientes com demência inicial por doença de Alzheimer

Abstract

New technologies have helped the biological diagnosis of Alzheimer’s dementia to make it more accurate over the years. However, establishing the prognosis for each case is still a significant challenge, as there are different cognitive profiles in the same diagnosis. Also, there is no well-defined standard for a cognitive profile that predicts future impairment of functionality. In this sense, a better understanding of cognitive phenotypes can help establish prognosis of Alzheimer’s dementia. Objective: Identify cognitive subtypes based on the neuropsychological assessment results of patients with probable Alzheimer’s dementia and compare their functional impairment. Method: The study comprised 134 participants with Alzheimer disease recruited from the reference center with mild cognitive impairment and dementia. We conducted a complete neuropsychological assessment evaluating the domains: memory, executive functions, language, simple attention/processing speed, and visuospatial abilities, and the assessment of self-care, domestic and complex activities of the activities of daily living. We performed a cluster analysis using Ward’s Hierarchical Method. Results: Data analysis suggested the existence of five cognitive subgroups. The general comparison, performed by the Kruskal-Wallis test, suggests that we found the groups to differ in the neuropsychological assessment instruments. Cognitive phenotypes vary about impaired and/or preserved ability, as well as the severity of impairment. The cognitive phenotypes found differentiated about education, observed a lower level of formal education in the cognitive phenotype with accentuated global impairment and a higher formal education in the profiles with less accentuated impairment. Comparison of expected impairments using the General Activities of Daily Living Scale shows that the cognitive profiles found to differ in basic activities, but not in instrumental activities. Conclusions: There are different cognitive profiles in patients with Alzheimer’s disease. In this sense, this study identified five cognitive subgroups that differ in terms of symptom severity and impaired abilities. Cognitive phenotypes differ in relation to basic activities, but not in instrumental activities. In addition, the proposed model suggested that the impairment in performing basic activities differed in relation to education and small or more pronounced decline. Especially in assessment: visual-spatial abilities, simple attention/processing speed and planning.