scholarly journals THE ROSAS COHORT: A PROSPECTIVE, LONGITUDINAL STUDY OF BIOMARKERS FOR ALZHEIMER’S DISEASE. STRATEGY, METHODS AND INITIAL RESULTS

Author(s):  
A. de Mauléon ◽  
M. Soto ◽  
V. Kiyasova ◽  
J. Delrieu ◽  
I. Guignot ◽  
...  

Objective: The aims of the Research Of biomarkers in Alzheimer’s diseaSe (ROSAS) study were to determine the biofluid and imaging biomarkers permitting an early diagnosis of Alzheimer’s disease and better characterisation of cognitive and behavioural course of the pathology. This paper outlines the overall strategy, methodology of the study, baseline characteristics of the population and first longitudinal results from the ROSAS cohort. Methods: Longitudinal prospective monocentric observational study performed at the Alzheimer’s disease Research centre in Toulouse. A total of 387 patients were studied and analyzed in 3 groups: 184 patients with dementia of Alzheimer’s type, 96 patients with memory disorders without dementia (Mild Cognitive Impairment) and 107 patients without abnormal memory tests (control group), and were followed up during 4 years. Patient’s sociodemographic characteristics, risk factors, medical conditions, previous and current medications, neuropsychological assessment and overall cognitive status were recorded. Blood and urine samples were collected at every year, Magnetic Resonance Imaging were performed at inclusion, after one year of follow-up and at the end of the study. Results: At baseline, three different groups of the cohort differed interestingly in age, level of education, and in percentage of ApoEε4 carriers whereas the history of cardiovascular and endocrine pathologies were similar among the groups. During the follow-up period (3-4 years) 42 mild cognitive impairment patients (43.8%) progressed to dementia, 7 controls progressed into mild cognitive impairment and 1 patient in the control group converted from mild cognitive impairment group to dementia of Alzheimer’s type group. During the first year of follow up, the incidence of progression from mild cognitive impairment to dementia of Alzheimer’s type was 12.7 per 100, during the second year 33.9 per 100 and 46.7 per 100 for the third year. Conclusion: This paper presents the baseline characteristics of the unique French prospective monocenter study in which the natural course of dementia of Alzheimer’s type was evaluated. Future analysis of blood and urine samples collection from the ROSAS study will permit to identify possible biofluid biomarkers predicting the early stages of the dementia of Alzheimer’s type and risk of progression from Mild Cognitive Impairment to Alzheimer’s disease.

2012 ◽  
Vol 24 (6) ◽  
pp. 948-958 ◽  
Author(s):  
Josep L. Conde-Sala ◽  
Josep Garre-Olmo ◽  
Joan Vilalta-Franch ◽  
Jordi Llinàs-Reglà ◽  
Oriol Turró-Garriga ◽  
...  

ABSTRACTBackground: There are discrepant findings regarding which subscales of the Cambridge Cognitive Examination (CAMCOG) are able to predict cognitive decline. The study aimed to identify the baseline CAMCOG subscales that can discriminate between patients and predict cognitive decline in Alzheimer's disease (AD) and mild cognitive impairment (MCI).Methods: This was a five-year case-control study of patients with cognitive impairment and a control group. Participants were grouped into AD (n = 121), MCI converted to dementia (MCI-Ad, n = 43), MCI-stable (MCI-St, n = 66), and controls (CTR, n = 112). Differences in the mean scores obtained by the four groups were examined. Receiver operating characteristic curves were used to compare subscale scores in the AD and MCI-Ad groups with those of controls. The influence of age, gender, schooling, and depression on baseline subscale scores was assessed.Results: Of the CAMCOG subscales, Orientation and Memory (learning and recent) (OR + MEM) showed the highest discriminant capacity in the baseline analysis of the four groups. This baseline analysis indicated that OR + MEM was the best predictor of conversion to AD in the MCI-Ad group (area under the curve, AUC = 0.81), whereas the predictive capacity of the global MMSE and CAMCOG scores was poor (AUC = 0.59 and 0.53, respectively).Conclusions: In the baseline analysis, the Orientation and Memory (learning and recent) subscales showed the highest discriminant and predictive capacity as regards both cognitive decline in the AD group and conversion to AD among MCI-Ad patients. This was not affected by age, gender, schooling, or depression.


2020 ◽  
Vol 17 ◽  
Author(s):  
Hyung-Ji Kim ◽  
Jae-Hong Lee ◽  
E-nae Cheong ◽  
Sung-Eun Chung ◽  
Sungyang Jo ◽  
...  

Background: Amyloid PET allows for the assessment of amyloid β status in the brain, distinguishing true Alzheimer’s disease from Alzheimer’s disease-mimicking conditions. Around 15–20% of patients with clinically probable Alzheimer’s disease have been found to have no significant Alzheimer’s pathology on amyloid PET. However, a limited number of studies had been conducted this subpopulation in terms of clinical progression. Objective: We investigated the risk factors that could affect the progression to dementia in patients with amyloid-negative amnestic mild cognitive impairment (MCI). Methods: This study was a single-institutional, retrospective cohort study of patients over the age of 50 with amyloidnegative amnestic MCI who visited the memory clinic of Asan Medical Center with a follow-up period of more than 36 months. All participants underwent brain magnetic resonance imaging (MRI), detailed neuropsychological testing, and fluorine-18[F18]-florbetaben amyloid PET. Results: During the follow-up period, 39 of 107 patients progressed to dementia from amnestic MCI. In comparison with the stationary group, the progressed group had a more severe impairment in verbal and visual episodic memory function and hippocampal atrophy, which showed an Alzheimer’s disease-like pattern despite the lack of evidence for significant Alzheimer’s disease pathology. Voxel-based morphometric MRI analysis revealed that the progressed group had a reduced gray matter volume in the bilateral cerebellar cortices, right temporal cortex, and bilateral insular cortices. Conclusion: Considering the lack of evidence of amyloid pathology, clinical progression of these subpopulation may be caused by other neuropathologies such as TDP-43, abnormal tau or alpha synuclein that lead to neurodegeneration independent of amyloid-driven pathway. Further prospective studies incorporating biomarkers of Alzheimer’s diseasemimicking dementia are warranted.


2016 ◽  
Vol 52 (1) ◽  
pp. 133-143 ◽  
Author(s):  
María Eugenia López ◽  
Agustín Turrero ◽  
Pablo Cuesta ◽  
David López-Sanz ◽  
Ricardo Bruña ◽  
...  

2020 ◽  
pp. 1-8
Author(s):  
Edith Labos ◽  
Edith Labos ◽  
Sofia Trojanowski ◽  
Karina Zabala ◽  
Miriam Del Rio ◽  
...  

The increase in consultations for changes and/or cognitive complaints in the elderly, together with the current interest in epidemiological research in this context creates the need for screening tools for cognitive assessment to enable the detection of early deficits. Evidence shows its predictive value in the development of dementia disease. This study aims at displaying the results of a Cognitive Skills Questionnaire (CSQ) in a patient population with mild cognitive impairment (MCI) and Alzheimer’s disease (AD), both compared with a control group (CG) with no cognitive disorder and verifying its sensitivity and specificity in order to identify risk patients with cognitive disorder. Participants and Methods: A total of 208 participants were evaluated, out of which 60 had MCI, 46 had AD and a remaining group of 102 subjects who had no cognitive disorder. All participants were administrated the CSQ and a battery of neuropsychological proofs. We analysed the statistical data using ANOVA, Student’s t-test, Tuckey test, ROC curve and principal components analysis. A multiple regression analysis was carried out so as to single out those questions which better differentiated the studied groups. Results: The CSQ showed significant differences between the CG and both groups of patients (AD p> 0.01 and MCI p> 0.05). It was established a cut-off point of 17.5 in the CSQ total score with a sensitivity of 93% and a specificity of 91.3%. Conclusion: The CSQ could eventually allow us to identify patients with cognitive disorders and those others with a cognitive complaint greater than expected. Thus, this questionnaire could be a useful testing and counselling tool in health primary attention.


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