Optinių iliuzijų ir kitų regimojo suvokimo užduoűių atlikimas, sergant Alzheimerio liga.

Background. Prevalence of Alzheimer's disease (AD) is increasing due to the aging of the population. As a result the economic burden of AD is increasing as well. Early diagnosis and timely interventions are needed in order to reduce the cost of care for patients with AD. Visuospatial perception has recently drawn attention as one of the earliest symptoms of AD that could be useful in early diagnosis of the disease. There are some aspects of visual cognition that have not been studied extensively in patients with AD. There are still some uncertainties regarding impairment in visuospatial functions in AD such as the exact nature of these symptoms and the time of on set in the course of the disease. Purpose of the study. To evaluate visual perception and susceptibility to optical illusions in patients with mild and moderate AD. Materials and methods. The study was conducted in the department of Neurology at Vilnius University Hospital Santariškių Klinikos. We en rolled 23 patients with mild to moderate AD and 25 cognitively normal control subjects, matched for age, sex, level of education and type of occupation. Visual perception and susceptibility to optical illusions were assessed using a set of 32 pictures that were divided into six groups according to mechanisms of perception. Cognitive functions were assessed using Mini-Mental State Examination (MMSE). Results. Patients with AD were significantly less susceptible than control subjects to 2 out of 4 geometrical illusions (p<0.001). They were also less susceptible to 1 out of 3 colour illusions (p=0.046). De creased susceptibility to optical illusions was present in the stage of mild dementia (MMSE>20 pts.). Performance in embedded images tasks was significantly (p<0.05) worse in AD patients in 7 out of 8 cases. Patients with mild dementia were significantly worse than control subjects in evaluating 3 of these pictures. Patients with AD identified both possible meanings less frequently than control subjects in 1 out of 3 pictures of ambiguous figures (p=0.001). AD patients made significantly more mistakes than control subjects in 4 out of 8 optical paradoxes tasks (p 0.02 -- <0.001). Mild dementia patients' performance was significantly different from control group in 2 of these tasks. There were no significant differencies between patients with AD and control subjects in perception of motion illusions. Conclusions. Visual perception is impaired in AD. Deficits in visual perception occur early in the course of the disease. They are present in patients with mild dementia. [ABSTRACT FROM AUTHOR]