NEUROPSYCHOLOGICAL MARKERS OF DEMENTIA ON VISUAL-SPATIAL TASKS - A COMPARISON BETWEEN ALZHEIMERS TYPE AND VASCULAR FORMS OF DEMENTIA

The incidence of the "closing-in" phenomenon and of the tendency to gi ve "primitive answers" on the Raven's Colored Matrices was studied in 50 normal subjects and in two groups of Alzheimer's type (n = 41) and of vascular (n = 35) dementia patients, carefully matched as for the o verall severity of dementia and the degree of visual-spatial impairmen t. The aims of this research were to determine if these patterns of be havior can be considered as neuropsychological markers of dementia and if their incidence is similar in the two dementia groups. Results sho w that both the closing-in phenomenon and the tendency to give globali stic and odd responses on the Raven's Colored Matrices are good marker s of dementia and that, in particular, they point to a degenerative, r ather than to a vascular form of dementia. From the clinical point of view, these data suggest that a qualitative analysis of the patient's behavior can increase the diagnostic efficacy of neuropsychological te sts and that neuropsychological markers of dementia point more to Alzh eimer's disease (considered as the most prototypic form of dementia) t han to a vascular form of dementia even when the two groups of patient s are well balanced in terms of visual-spatial impairment and the over all severity of dementia.