[Mild cognitive impairment: the neuropsychological characteristics of the different subtypes]

Abstract

Aim: To evaluate the frequency of mild cognitive impairment (MCI) subtypes and their neuropsychological characteristics in our population, and estimate the change in this frequency according to the extension of the neuropsychological examination.

Patients and methods: Patients with diagnostic of MCI were included from 01/01/2003 to 31/12/2007. MCI was classified as MCI-amnestic type (MCI-AT), MCI-multiple domain type (MCI-MDT) and MCI-single domain non amnestic (MCI-MNOA). A neuropsychological test was considered abnormal if its result was equal or less than 1.5 standard deviations from what expected for age and educational level. The cohort was divided in short evaluation (less than 14 test, from 2003-2005) and basic-extended evaluation (equal or more than 14 test, from 2006-2007).

Results: Out of 204 patients included, 51 (26%) were classified as MCI-AT, 11 (5,4%) as MCI-MNOA and 142 (69,9%) as MCI-MDT. A higher educational level was associated with an increase in the number of MCI-MDT. The longer the evaluation, the greater was the proportion of MCI-MDT and MCI-MNOA and the lower the proportion of MCI-AT, without statistical significance.

Conclusions: The most frequent MCI subtype was MCI-MDT. A more extended evaluation would allow a better classification of MCI subtypes and increase the number of MCI-MDT and MCI-MNOA at the expense of MCI-AT.