Hippocampal size and memory function in the ninth and tenth decades of life: the Sydney Older Persons Study.
OBJECTIVE
The purpose of this study was to define magnetic resonance imaging (MRI) correlates of normal brain ageing, with the specific objective of investigating whether the size of the hippocampus is selectively correlated with age related memory performance in non-demented individuals in their ninth and tenth decades of life.


METHODS
Hippocampal size was estimated using MRI based volumetry and qualitative visual assessment in 102 community dwelling individuals aged between 81 and 94 years. Participants were evaluated on a variety of clinical and experimental instruments, including a comprehensive neuropsychological test battery. All participants underwent neurological examination, an extensive medical history was obtained, and an informant confirmed details of each participant's functional ability.


RESULTS
Both visual and volumetric hippocampal measures were identified as robust predictors of memory performance, even when the influence of age related illnesses and sociodemographic variables was accounted for. When the sample was reduced to include the most cognitively healthy participants who were rated by an informant as showing no evidence of cognitive decline, the left hippocampal measures remained significant predictors of delayed retention of verbal material.


CONCLUSIONS
These findings suggest that hippocampal volumes are selectively correlated with memory functioning in both normal and successful ageing.
Lye
T C
TC
Centre for Education and Research on Ageing, Concord Hospital C25, Concord NSW 2139, Sydney, Australia. tlye@medicine.usyd.edu.au
Piguet
O
O
Grayson
D A
DA
Creasey
H
H
Ridley
L J
LJ
Bennett
H P
HP
Broe
G A
GA
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001284:Atrophy; D002540:Cerebral Cortex / Q000473:pathology; D002552:Cerebral Ventricles / Q000473:pathology; D004292:Dominance, Cerebral / Q000502:physiology; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008568:Memory / Q000502:physiology*; D015999:Multivariate Analysis; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D009517:New South Wales; D011594:Psychometrics; D012016:Reference Values