Laura Serra1, Laura Petrosini2, Andrea Salaris1, Lorenzo Pica1, Michela Bruschini1, Carlotta Di Domenico1, Carlo Caltagirone3, Camillo Marra4, Marco Bozzali1,5. 1. Neuroimaging Laboratory, Santa Lucia Foundation, IRCCS, Rome, Italy. 2. Laboratory of Experimental and Behavioural Neurophysiology, IRCCS Fondazione Santa Lucia, Rome, Italy. 3. Department of Clinical and Behavioural Neurology, Santa Lucia Foundation, IRCCS, Rome, Italy. 4. Institute of Neurology, Catholic University, Rome, Italy. 5. Brighton & Sussex Medical School, CISC, University of Sussex, Brighton, Falmer East Sussex, UK.
Abstract
BACKGROUND: Cognitive reserve (CR) explains the individual resilience to neurodegeneration. Years of formal education express the static measure of reserve (sCR). A dynamic aspect of CR (dCR) has been recently proposed. OBJECTIVE: The aim of the study was to compare sCR and dCR indexes, respectively, to detect brain abnormalities in Alzheimer's disease (AD) patients. METHODS: 117 individuals [39 AD, 40 amnestic mild cognitive impairment (aMCI), 38 healthy subjects (HS)] underwent neuropsychological evaluation and a 3T-MRI. T1-weighted volumes were used for manual segmentation of the hippocampus and of the parahippocampal cortices. Years of formal education were used as an index of sCR. Partial Least Square analysis was used to decompose the variance of individual MMSE scores, considered as a dCR index. In aMCI and AD patients, the brain abnormalities have been assessed comparing individuals with high and low levels of sCR and dCR in turn. Moreover, we investigated the effect of the different CR indexes in mediating the relationship between changes in brain volumes and memory performances. RESULTS: sCR and dCR indexes classified differently individuals having high or low levels of CR. Smaller hippocampal and parahippocampal volumes in high dCR patients were found. The sCR and dCR indexes mediated significantly the relationship between brain abnormalities and memory in patients. CONCLUSIONS: CR mediated the relationship between brain and memory dysfunctions. We hypothesized that sCR and dCR indexes are a representation of different warehouses of reserve not operating in parallel but forming a complex system, in which crystalized cognitive abilities and actual cognitive efficiency interact with brain atrophy impacting on memory.
BACKGROUND: Cognitive reserve (CR) explains the individual resilience to neurodegeneration. Years of formal education express the static measure of reserve (sCR). A dynamic aspect of CR (dCR) has been recently proposed. OBJECTIVE: The aim of the study was to compare sCR and dCR indexes, respectively, to detect brain abnormalities in Alzheimer's disease (AD) patients. METHODS: 117 individuals [39 AD, 40 amnestic mild cognitive impairment (aMCI), 38 healthy subjects (HS)] underwent neuropsychological evaluation and a 3T-MRI. T1-weighted volumes were used for manual segmentation of the hippocampus and of the parahippocampal cortices. Years of formal education were used as an index of sCR. Partial Least Square analysis was used to decompose the variance of individual MMSE scores, considered as a dCR index. In aMCI and ADpatients, the brain abnormalities have been assessed comparing individuals with high and low levels of sCR and dCR in turn. Moreover, we investigated the effect of the different CR indexes in mediating the relationship between changes in brain volumes and memory performances. RESULTS: sCR and dCR indexes classified differently individuals having high or low levels of CR. Smaller hippocampal and parahippocampal volumes in high dCRpatients were found. The sCR and dCR indexes mediated significantly the relationship between brain abnormalities and memory in patients. CONCLUSIONS:CR mediated the relationship between brain and memory dysfunctions. We hypothesized that sCR and dCR indexes are a representation of different warehouses of reserve not operating in parallel but forming a complex system, in which crystalized cognitive abilities and actual cognitive efficiency interact with brain atrophy impacting on memory.
Authors: Hyung-Jun Yoon; Seung-Gon Kim; Sang Hoon Kim; Jong Inn Woo; Eun Hyun Seo Journal: Int J Environ Res Public Health Date: 2021-11-19 Impact factor: 3.390
Authors: Martina Ferrari-Díaz; Ricardo Iván Bravo-Chávez; Juan Silva-Pereyra; Thalía Fernández; Carmen García-Peña; Mario Rodríguez-Camacho Journal: Front Aging Neurosci Date: 2022-10-04 Impact factor: 5.702