Right parietal cortex and calculation processing. Intra-operative functional mapping of multiplication and addition

摘要

functionaludmapping of these areas has been only partially explored, however, and only a few discordant data are availableudin the surgical literature with regard to the right parietal lobe. The purpose of this study was to evaluate the clinicaludimpact of simple calculation in cortical electrostimulation of right-handed patients affected by a right parietal brainudtumor.udMethods. Calculation mapping in awake surgery was performed in 3 right-handed patients affected by highgradeudgliomas located in the right parietal lobe. Preoperatively, none of the patients presented with calculation deficits.udIn all 3 cases, after sensorimotor and language mapping, cortical and intraparietal sulcus areas involved in singledigitudmultiplication and addition calculations were mapped using bipolar electrostimulation.udResults. In all patients, different sites of the right parietal cortex, mainly in the inferior lobule, were detected asudbeing specifically related to calculation (multiplication or addition). In 2 patients the intraparietal sulcus was functionallyudspecific for multiplication. No functional sites for language were detected. All sites functional for calculationudwere spared during tumor resection, which was complete in all cases without postoperative neurological deficits.udConclusions. These findings provide intraoperative data in support of an anatomofunctional organization forudmultiplication and addition within the right parietal area. Furthermore, the study shows the potential clinical relevanceudof intraoperative mapping of calculation in patients undergoing surgery in the right parietal area. Further andudlarger studies are needed to confirm these data and assess whether mapped areas are effectively essential for function.