DISTURBED VISUOSPATIAL ORIENTATION IN THE EARLY-STAGE OF ALZHEIMERS DEMENTIA

A pilot study was conducted to assess previously unrecognized visuo-sp atial disturbances in 45 Alzheimer's demented (AD) patients and 59 con trol persons all over the age of 65 years, living in the community, Th e results of the Clock Drawing Test (CDT) revealed high frequency (78% ) of deficient performative visuo-spatial skills of mild and moderate demented AD patients, The severity of dementia was found to be a good predictor of the deficit in visuoconstructive performance, The most fr equent drawing mistakes were the misplacement of numbers and clock han ds, which may relate to dysfunctions of the right inferior parietal co rtex. The right-left orientation (RLO) for the own body was not deteri orated in AD patients. However, significantly lower scores for RLO in the mental rotation subtest were found in mild and moderate AD groups, There were large inter-individual differences in the test scores of b oth demented groups, Thirty-one percent and 49% of the AD patients sco red 0 points or within the normal range (more than 4 points), respecti vely, indicating a pseudofocal onset pattern of the dementia, The resu lts of the CDT and Right-Left Orientation Test (RLOT) with mental rota tion showed significant positive correlation with other cognitive func tions of Mini Mental State Exam, such as attention-calculation, recall and writing, and indicate that the visuo-spatial orientation (VSO) is a composite of different cognitive skills. The CDT and RLOT appears t o be a useful tool for screening the elderly for disturbed VSO.