Qualitative patterns at Raven's colored progressive matrices in mild cognitive impairment and Alzheimer's disease

Background Visuo-spatial and problem-solving abilities are commonly impaired in patients with Alzheimer's disease (AD). Conversely, subjects with amnestic mild cognitive impairment (aMCI) do not exhibit overt involvement of cognitive domains other than memory. Consequently, a detection of an impairment at the Raven's colored progressive matrices (RCPM) could be useful to discriminate aMCI from AD and to mark the progression from one condition to another. Aim of the study To describe the pattern of errors at RCPM in subjects suffering from AD as compared with that of aMCI. Methods Fifteen patients with AD, 15 subjects with aMCI and 31 Healthy Controls (HC) received the RCPM. The errors were classified as: (1) difference (D); (2) inadequate individuation (II); (3) repetition of the pattern (RP); (4) incomplete correlation (IC). Results No difference approached significance between aMCI subjects and HC. AD patients always exhibited a higher number of errors as compared with HC. AD patients showed higher number of errors as compared with aMCI only on RP and IC errors. Conclusions The results suggest that the visuo-spatial and problem-solving impairment that characterize AD, and probably subtend the progression from aMCI to dementia, do not affect to the same extent all cognitive dimensions explored by RCPM.