Dados do Trabalho

Título

Subjective Cognitive Decline and Cognitive Reserve project: protocol and preliminary results

Resumo

Introduction: Subjective Cognitive Decline (SCD) is a condition characterized by consistent cognitive complaint in cognitively unimpaired (CU) individuals and is associated with progressive cognitive impairment, especially in the context of Alzheimer's disease (AD). Cognitive Reserve is the capacity to maintain cognitive abilities despite pathological damage. Studying the relationship between these two concepts is fundamental to understand the early stages of AD. Objectives: We aimed to show the study protocol and the preliminary results of the study. Methods: CU individuals with > 65 years old with cognitive complaints and with less than 5 or more than 10 years of formal education were recruited. Exclusion criteria were the previous diagnosis of dementia, uncontrolled neuropsychiatric/clinical illness, or cerebrovascular disease. The assessment was performed exclusively by phone calls. It consisted of a brief cognitive (Modified Telephone Interview for Cognitive Status - TICS-M) and anxiety/depression screenings, in addition to the SCD-scale. Individuals recruited were then evaluated in person with an extensive cognitive battery. Blood, cerebrospinal fluid, and saliva were collected to measure AD biomarkers (β-amyloid-42, total/phosphorylated tau), APOE genotyping and magnetic resonance imaging were also performed. Results: Between March and April 2022, 11 patients were included (90.1%, n=10/11 were female). Their median interquartile range (IQR) age was 70.5 (68.3-75) years old, with a median of 16 years of formal education for those in the high education group and 4 years for those with low education. The median TICS-M and SCD scores at the recruitment stages were 25 (IQR 20.8-26.5) and 8.5 (IQR 7-9), respectively. The main SCD-plus criteria reported were age at onset of SCD ≥ 60 years old (100%, n=11/11) and concerns associated with SCD (72.7%, n=8/11). Clinical Dementia Rating (CDR) global score was 0 in most patients (81.8%, n=9/11) – only 2 scored 0.5 (18.2%). In the cognitive battery, deficits were observed mainly in the Digit Span Memory Test (45.5%, n=5/11) and in the Five Digit Test (up to 54.5%, n=6/11). Conclusions: Most of the patients included had the diagnosis of SCD, showing that the telephone screening might be effective. The expansion of the sample may help us better understand the impact of cognitive reserve on the early stages of AD.