title: Early-onset Alzheimer's disease is associated with greater pathologic burden.
abstract: Two subtypes of Alzheimer's disease (AD) have been commonly identified: early- and late-onset forms. Previous studies suggest that early-onset AD patients have more neuritic plaques (NPs) and neurofibrillary tangles (NFTs). In the current study, NP and NFT counts were performed for 8 brain regions in 25 subjects with definite AD. A repeated-measures analysis of variance of mean regional NP and NFT counts for early- and late-onset groups was performed. A significant between-subject effect indicating greater overall NP and NFT burden in the early-onset group was observed (NP: F = 6.8, df = 1, P = .015; NFT: F = 7.5, df = 1, P = .012). This analysis supports the hypothesis that early-onset AD is associated with greater pathologic burden than late-onset AD. This suggests that late-onset AD patients have less cognitive reserve than early-onset patients and require fewer pathologic changes to exhibit cognitive deterioration.
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, USA. gamarchall@partners.org
authors.forename: Gad A
authors.initials: GA
authors.lastname: Marshall
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Fairbanks
authors.forename: Sibel
authors.initials: S
authors.lastname: Tekin
authors.forename: Harry V
authors.initials: HV
authors.lastname: Vinters
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Cummings
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000145:classification / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D002540:Cerebral Cortex / Q000473:pathology; D015331:Cohort Studies; D003937:Diagnosis, Differential; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016874:Neurofibrillary Tangles / Q000473:pathology*; D058225:Plaque, Amyloid / Q000473:pathology*; D012189:Retrospective Studies; D013569:Synapses / Q000473:pathology