We describe the case of a right-handed patient who presented a severe acalculia in the context of a pure Gerstmann syndrome following a subangular lesion that spared the left inferior parietal lobule (IPL). The patient showed impairments in Arabic and verbal codes, in number production and comprehension, as well as in numerical facts and problem solving. By using the EC301 calculation battery, semantic and syntactic tasks in Arabic and verbal codes, we tested the different hypotheses raised by the cognitive neuropsychological models of acalculia. The patients' difficulties, which were not associated with a general intellectual deterioration, and those affecting number processing as a particular semantic class, were indicative of a "global acalculia". This deficit, which exceeded the anarithmetia usually described in Gerstmann syndrome following left IPL lesion, suggested that the isolation of this area may constitute a sufficient condition for producing such a global acalculia. These results are discussed in terms of a disorder in the manipulation of mental images of spatially related objects.
Bibliographical noteFunding Information:
We thank Professors Alfonso Caramazza and Xavier Seron for their helpful discussions about this case. This research was supported by the Swiss National Science Foundation grants No. 31-61680-00 and 3100-056782-99.
- Gerstmann syndrome
- Left parietal lesion
- Number processing
ASJC Scopus subject areas
- Arts and Humanities (miscellaneous)
- Clinical Neurology