[Stability of the cognitive dimensions of a battery of neuropsychological tests]

Neuropsychological assessment allows the appraisal of the cognitive state of people with Mild Cognitive Impairment (MCI) by means of tests that are related to diverse cognitive functions. Most of the tests refer to more than one cognitive function, and the analysis of the individual's performance should take this into account. We analyzed the possible grouping of the tests of a neuropsychological battery into diverse cognitive dimensions, and the weight of the tests in each dimension. Participants were 223, 179, and 145 individuals (healthy and MCI) from a longitudinal study on MCI, who were assessed with a battery of neuropsychological tests on one, two, or three occasions, respectively. By means of exploratory factor analysis, the tests were found to be grouped into diverse factors. Although the three-factor solution was also analyzed, the two-factor solution was the best one, with a factor that included the memory tests, and the other factor comprising the executive function and praxis tests. Factor analysis allowed us to detect two clear cognitive dimensions with high convergence in all three assessments and, as a consequence, the reduction of the battery is proposed, selecting the tests with a greater weight in each dimension.