The diagnostic value of saccadic profile in Alzheimer's disease

Introduction Appearing in the early stages of the disease pathological changes in different parts of the brain in Alzheimer's disease (AD) subjects cause disruption of neural circuits between the cortex and the basal ganglia. It may affect the ocular movement disturbances. Objectives In previous studies we have shown that AD patients present abnormalities of saccadic eye movements. In this study, we conducted for the first time the advanced quantitative analysis profile of saccades on a large study group. Aims The aim of this study is to find the features and the values of parameters in patients with AD differ from healthy individuals using quantitative measurement methods that could help in the future to differentiate people with an uncertain diagnosis. Methods Seventy-one patients with mild and moderate AD (age 79.1 ± 5.21) were examined. Forty-four healthy ones (C) without symptoms of dementia, matched for sex, age and education level (age 78.3 ± 4.7) were examined. In this study we made use of the Saccadometer Advanced (ACI, Cambridge, UK), allowing the measurement of eye position with the time resolution of 1 ms (1000 Hz). Results Statistically significant differences between AD and C groups were found ( P  0.05). The analysis of saccadic profile allows to differentiate Alzheimer's disease. The rising slope duration and the rising slope percent is lower in AD group, but the falling slope duration and the falling slope percent is larger in AD group. Conclusions AD patients have much smaller slope in the rising phase of the saccade. The results show that the use of saccadometry may improve diagnosis of the AD.