Mini-mental state examination in Alzheimer's disease and multi-infarct dementia

The aim of this study was to compare the performances on each item of the Mini-Mental State Examination (MMSE) of patients with Alzheimer's disease (AD) and multi-infarct dementia (MID). In order to identify the items that could better distinguish the two groups of patients, 70 AD and 31 MID patients matched for disease severity, age, and education were evaluated. The scores of the 101 patients on each of the MMSE items were entered into a principal component factor analysis using varimax rotation, and two main components were derived. Component 1 was probably representative of recently acquired information, whereas component 2 represented educational level. A score summing the items that loaded on component 1 and the recall item was calculated to generate a measure of episodic memory. Performing analysis of variance and covarying for age and education revealed that this score was statistically different in the two groups, with AD patients having lower values. The data suggest that the MMSE may demonstrate a pattern of impairment of memory that differs between AD and MID. Possible explanations of this finding should take into account the different neuroanatomical impairments and the different degrees of motivation, due to depression or attentional deficits, toward external stimuli.