Personality, Alzheimer's disease and behavioural and cognitive symptoms of dementia: the PACO prospective cohort study protocol

International audienceBACKGROUND: Alzheimer's disease is characterised by a loss of cognitive function and behavioural problems as set out in the term "Behavioural and Psychological Symptoms of Dementia". These behavioural symptoms have heavy consequences for the patients and their families. A greater understanding of behavioural symptoms risk factors would allow better detection of those patients, a better understanding of crisis situations and better management of these patients. Some retrospective studies or simple observations suggested that personality could play a role in the occurrence of behavioural symptoms. Finally, performance in social cognition like facial recognition and perspective taking could be linked to certain personality traits and the subsequent risks of behavioural symptoms. We propose to clarify this through a prospective, multicentre, multidisciplinary study. Main Objective: -To assess the effect of personality and life events on the risk of developing behavioural symptoms. Secondary Objectives: -To evaluate, at the time of inclusion, the connection between personality and performance in social cognition tests; -To evaluate the correlation between performance in social cognition at inclusion and the risks of occurrence of behavioural symptoms; -To evaluate the correlation between regional cerebral atrophy, using brain Magnetic Resonance Imaging at baseline, and the risk of behavioural symptoms.METHODS/DESIGN: Study type and Population: Prospective multicentre cohort study with 252 patients with Alzheimer's disease at prodromal or mild dementia stage. The inclusion period will be of 18 months and the patients will be followed during 18 months. The initial evaluation will include: a clinical and neuropsychological examination, collection of behavioural symptoms data (Neuropsychiatric-Inventory scale) and their risk factors, a personality study using both a dimensional (personality traits) and categorical approach, an inventory of life events, social cognition tests and an Magnetic Resonance Imaging. Patients will be followed every 6 months (clinical examination and collection of behavioural symptoms data and risk factors) during 18 months.DISCUSSION: This study aims at better identifying the patients with Alzheimer's disease at high risk of developing behavioural symptoms, to anticipate, detect and quickly treat these disorders and so, prevent serious consequences for the patient and his caregivers.TRIAL REGISTRATION: ClincalTrials.gov: NCT01297140

Brain Volume Predicts Behavioral and Psychological Symptoms in Alzheimer’s Disease

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SORL1 rare variants: a major risk factor for familial early-onset Alzheimer’s disease

International audienceThe SORL1 protein plays a protective role against the secretion of the amyloid β peptide, a key event in the pathogeny of Alzheimer's disease. We assessed the impact of SORL1 rare variants in early-onset Alzheimer's disease (EOAD) in a case-control setting. We conducted a whole exome analysis among 484 French EOAD patients and 498 ethnically matched controls. After collapsing rare variants (minor allele frequency ≤1%), we detected an enrichment of disruptive and predicted damaging missense SORL1 variants in cases (odds radio (OR)=5.03, 95% confidence interval (CI)=(2.02-14.99), P=7.49.10(-5)). This enrichment was even stronger when restricting the analysis to the 205 cases with a positive family history (OR=8.86, 95% CI=(3.35-27.31), P=3.82.10(-7)). We conclude that predicted damaging rare SORL1 variants are a strong risk factor for EOAD and that the association signal is mainly driven by cases with positive family history