title: Longitudinal association between hippocampus atrophy and episodic-memory decline.
abstract: There is marked variability in both onset and rate of episodic-memory decline in aging. Structural magnetic resonance imaging studies have revealed that the extent of age-related brain changes varies markedly across individuals. Past studies of whether regional atrophy accounts for episodic-memory decline in aging have yielded inconclusive findings. Here we related 15-year changes in episodic memory to 4-year changes in cortical and subcortical gray matter volume and in white-matter connectivity and lesions. In addition, changes in word fluency, fluid IQ (Block Design), and processing speed were estimated and related to structural brain changes. Significant negative change over time was observed for all cognitive and brain measures. A robust brain-cognition change-change association was observed for episodic-memory decline and atrophy in the hippocampus. This association was significant for older (65-80 years) but not middle-aged (55-60 years) participants and not sensitive to the assumption of ignorable attrition. Thus, these longitudinal findings highlight medial-temporal lobe system integrity as particularly crucial for maintaining episodic-memory functioning in older age.
authors.affiliation: Department of Statistics, Umeå School of Business and Economics, Umeå University, Umeå, Sweden. Electronic address: tetiana.gorbach@umu.se.
authors.forename: Tetiana
authors.initials: T
authors.lastname: Gorbach
authors.affiliation: Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, Umeå, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Pudas
authors.affiliation: Department of Statistics, Umeå School of Business and Economics, Umeå University, Umeå, Sweden; Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Lundquist
authors.affiliation: Department of Radiation Sciences, Umeå University, Umeå, Sweden.
authors.forename: Greger
authors.initials: G
authors.lastname: Orädd
authors.affiliation: Centre for Demographic and Ageing Research at Umeå University (CEDAR), Umeå University, Umeå, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Josefsson
authors.affiliation: Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, Umeå, Sweden; Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
authors.forename: Alireza
authors.initials: A
authors.lastname: Salami
authors.affiliation: Department of Statistics, Umeå School of Business and Economics, Umeå University, Umeå, Sweden.
authors.forename: Xavier
authors.initials: X
authors.lastname: de Luna
authors.affiliation: Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, Umeå, Sweden; Department of Radiation Sciences, Umeå University, Umeå, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Nyberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000523:psychology*; D005260:Female; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000473:pathology* / Q000523:psychology*; D061212:Memory, Episodic; D008875:Middle Aged; D011930:Reaction Time; D013997:Time Factors
keywords: Aging; Cognitive decline; Episodic memory; Hippocampus; Longitudinal changes; Nonignorable attrition