title: Cognition, brain atrophy, and cerebrospinal fluid biomarkers changes from preclinical to dementia stage of Alzheimer's disease and the influence of apolipoprotein e.
abstract: BACKGROUND
  Knowledge of Alzheimer's disease (AD) manifestation in the pre-dementia stage facilitates the selection of appropriate measures for early detection and disease progression.
  
  
  OBJECTIVE
  To examine the trajectories of cognitive performance, gray matter volume (GMV), and cerebrospinal fluid (CSF) biomarkers, together with the influence of apolipoprotein E (APOE) in subjects with amyloid-β (Aβ) deposits across the pre-clinical to dementia stages of AD.
  
  
  METHODS
  356 subjects were dichotomized into Aβ+ and Aβ- groups based on their CSF Aβ1-42 level. We derived AD-related atrophic regions (AD-ROIs) using the voxel-based morphometry approach. We characterized the trajectories of cognitive scores, GMV at AD-ROIs, and CSF biomarkers from preclinical to disease stages in Aβ+ subjects. The effect of APOE ε4 genotype on these trajectories was examined.
  
  
  RESULTS
  Impairments in executive functioning/processing speed (EF/PS) and atrophy at the right supramarginal/inferior parietal gyrus were detected in cognitively normal Aβ+ subjects. Together with the APOE ε4 carrier status, these measures showed potential to identify cognitively normal elderly with abnormal CSF Aβ1-42 level in another independent cohort. Subsequently, impairment in memory, visuospatial, language, and attention as well as atrophy in the temporal lobe, thalamus, and mid-cingulate cortex were detectable in Aβ+ mild cognitive impairment (MCI) subjects. In MCI and dementia Aβ+ subjects, ε4 carriers had more severe atrophy of the medial temporal lobe and memory impairment but higher EF/PS compared to non-carriers.
  
  
  CONCLUSIONS
  EF/PS decline and right parietal atrophy might act as non-invasive screening tests for abnormal amyloid deposition in cognitively normal elderly. APOE modulation on subsequent trajectories in cognition and atrophy should be taken into account when analyzing disease progression.
authors.affiliation: Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore.
authors.forename: Thomas Adi Kurnia
authors.initials: TA
authors.lastname: Susanto
authors.affiliation: Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore.
authors.forename: Emmanuel Peng Kiat
authors.initials: EP
authors.lastname: Pua
authors.affiliation: Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid / Q000150:complications / Q000235:genetics; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D000704:Analysis of Variance; D001057:Apolipoproteins E / Q000235:genetics*; D001284:Atrophy / Q000150:complications / Q000473:pathology; D015415:Biomarkers / Q000134:cerebrospinal fluid; D001921:Brain / Q000473:pathology*; D003072:Cognition Disorders / Q000209:etiology*; D015331:Cohort Studies; D003704:Dementia / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D011569:Psychiatric Status Rating Scales
chemical_list: D016229:Amyloid beta-Peptides; D001057:Apolipoproteins E; D015415:Biomarkers; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)
keywords: APOE genotype; Alzheimer's disease; amyloid-β deposition; magnetic resonance imaging; mild cognitive impairment; preclinical