Hippocampal magnetic resonance imaging morphometry and neuropsychological parameters in patients with Alzheimer's disease

Abstract

Alzheimer's disease (AD) is the leading cause of dementia in the population. Difficulties in diagnosing AD have served as an incentive for actively studying different current methods that increase the accuracy of diagnosis of the current neurodegenerative process in this disease. One of these areas is the post-processing of magnetic resonance imaging (MRI) data, by exactly calculating the volume of various anatomical formations, namely MRI morphometry. Objective: to determine the possible relationship between the results of evaluating the higher brain functions and the reduction in the hippocampal volume calculated by MRI morphometry in AD patients with mild and moderate dementia and in healthy controls. Patients and methods. Examinations were made in 41 AD patients aged 70.63±8.38 years with mild and moderate dementia and in healthy individuals. All study participants underwent neuropsychological testing that included the Mini-Mental State Examination (MMSE), the frontal lobe dysfunction battery (FLDB); immediate and delayed 12-word recall trials (12-word test); Benton's revised visual retention test; test of literal and categorical associations; clock drawing test; and series number test, Part A. MRI was performed on a Siemens Magnetom Skyra 3T MRI scanner. Statistical Parametric Mapping software was used to convert images and the volume of the hippocampus was estimated by FMRIB Software Library. Results and discussion. A statistically significant decrease in hippocampal volumes was established in patients with AD compared with healthy individuals. No statistically significant differences in hippocampal volumes were found in patients with varying degrees of dementia. Patients with mild and moderate dementia differed in all indicators of neuropsychological tests, with exception for the 12-word test and Benton's test. There was a statistically significant correlation of the total volume of the hippocampi with the indicators of MMSE, FLDB, 12- word test, clock drawing test, and test of categorical associations. Conclusion. Hippocampal MRI morphometry in combination with neuropsychological tests is an informative technique in the diagnosis of AD. There is a relationship between the degree of hippocampal atrophy and the neuropsychological characteristics of patients.

Keywords

• dementia
• alzheimer's disease
• magnetic resonance imaging
• morphometry