Journals of Gerontology Series A: Biological Sciences and Medical Sciences, Vol 50, Issue 2 M107-M113, Copyright © 1995 by The Gerontological Society of America
Episodic memory and visuospatial ability in detecting and staging dementia in a community-based sample of very old adults
A Herlitz, RD Hill, L Fratiglioni and L Backman
Stockholm Gerontology Research Center, Karolinska Institute, Sweden.
BACKGROUND. This study examined the efficacy of a cognitive test battery in
detecting and staging dementia in a community-based sample of very old
adults. METHOD. The sample consisted of 398 nondemented and 108 demented
adults taken from all the inhabitants in the Kungsholmen parish of
Stockholm, Sweden (2,368 individuals), aged 75 years and older, who were
part of a large-scale epidemiological study on aging and dementia.
Participants received a cognitive test battery that consisted of
specialized episodic memory tasks, as well as standardized psychometric
measures of visuospatial ability and primary memory. RESULTS. A
discriminant analysis revealed that highly supported episodic memory tasks
(recognition, cued recall) were primarily responsible for correctly
classifying normal old adults (94.5%) from those with the diagnosis of
dementia (66.7%). Using the Mini-Mental State Exam (MMSE) as the criterion
of dementia severity, a correct classification of 88.9% was achieved for
mildly demented subjects and 77.8% for moderately demented subjects.
Visuospatial tasks made the greatest contribution in distinguishing those
at different levels of dementia severity. CONCLUSION. The results of this
investigation indicate that cognitively supported measures assessing
episodic memory may be particularly useful in the detection of dementia,
whereas visuospatial measures are more effective in staging the disease.
Consistent with biological models of the progression of dementia, this
suggests that visuospatial abilities may deteriorate later and/or at a
slower rate than episodic memory skills in the early stages of dementia. It
is noteworthy that these conclusions are based on samples of very old
adults taken from the general population.
