[Acalculia. Neurological bases, evaluation and disorders].

OBJECTIVE

To make a review of the literature on alterations in mathematical ability secondary to structural cerebral lesions.

DEVELOPMENT AND

CONCLUSIONS

We refer to the initial classification of acalculia of Berger (secondary acalculia when this is due to broader neuropsychological deficits and primary acalculia when it occurs alone) to the classical division of Hecaen (alexia and numerical agraphia with or without alterations in reading and writing of letters and words, visuo-spatial acalculia due to alterations in the spatial organization of multi-digit figures and the partial results of arithmetical operations, anarithmetia or primary failure in mathematical ability) and the most recent classifications based on neurocognitive models, which subdivide the acalculias into those secondary to changes in the system for processing numbers and those due to changes in the cognitive system for mathematics (McCloskey and Caramazza). Similarly, we review the correlations between the clinical changes in mathematics and the cerebral localization of the causative lesions (left parieto-temporal, right and including frontal and subcortical associative areas) together with the association of acalculia and other neuropsychological deficits. Finally we review the neuropsychological instruments available for the evaluation of acalculias, with particular reference to the tools validated and scaled for our language and sociocultural setting.