Brain atrophy parameters of very old subjects in a population-based samplewith and without dementia syndrome

Atrophy parameters of the brain vary with age in healthy subjects. The aim of the study was to determine the range of atrophy parameters in subjects w ith very old age. Population-based data are especially necessary in order t o evaluate atrophy parameters of healthy old persons in clinical settings a nd for the diagnosis of dementia diseases. 254 subjects in a population-bas ed sample were investigated by a cranial computerized tomography (cCT). Age ranged from 70 to 99, 78 were 80-89 years old and 43 over 90 years of age; 24 demented subjects were diagnosed according to DSM-III-R. A planimetric analysis of the extracerebral CSF-space (ECSF) and relative area of the ven tricles (VBR) was performed. VBR and ECSF were used as primary atrophy para meters. The VBR, ECSF and other structural brain parameters for subjects of very old age are described after exclusion of dementia cases according to clinical diagnosis. A statistically significant age effect could be demonst rated as well as a dementia effect for the younger age groups (70-89). No d ifference in the atrophy parameters between the diagnostic groups, however, were found for the oldest groups (90 and older); for the very old subjects the scores of demented and non-demented participants were entirely within the same range. The age effect on atrophy parameters in non-demented subjec ts in very old age reaches the range of atrophy parameters, which is found in dementia. The question remains wheather the reason for this is a benign senescent brain atrophy or whether the amount of atrophic changes in very o ld age may explain the enhanced vulnerability for the development of dement ia syndromes in very old age and the steeply increasing incidence of dement ia or whether there is an incipient brain atrophy in more or less all very old subject and they will develop dementia if they do not die beforehand.