Article Text

Download PDFPDF
Intraoperative mapping of the cortical areas involved in multiplication and subtraction: an electrostimulation study in a patient with a left parietal glioma
  1. H Duffau1,3,
  2. D Denvil1,
  3. M Lopes1,
  4. F Gasparini1,
  5. L Cohen2,3,
  6. L Capelle1,3,
  7. R van Effenterre1
  1. 1Department of Neurosurgery, Hôpital de la Salpêtriére, Paris, France
  2. 2Department of Neurology, Hôpital de la Salpêtriére
  3. 3Department of IFR 49, Hôpital de la Salpêtriére
  1. Correspondence to:
 Dr H Duffau, Service de Neurochirurgie, Hôpital de la Salpêtriére, 47 Bd de l’hôpital, 75651 Paris, Cedex 13, France;
 hugues.duffau{at}psl.ap-hop-paris.fr

Abstract

Objectives: Advances in neuroimaging studies have recently improved the understanding of the functional anatomy of the calculation processes, having in particular underlined the central role of the angular gyrus (AG). In this study, the authors applied this knowledge to the surgical resection of a glioma invading the left AG, by localising and sparing the cortical areas involved in two different components of calculation (multiplication and subtraction), using direct electrical stimulations.

Methods: A calculation mapping was performed in a patient without deficit except a slightly impaired performance for serial arithmetic subtraction, during the resection under local anaesthesia of a left parieto-occipital glioma invading the dominant AG. After somatosensory and language mappings, cortical areas involved in single digit multiplications and subtractions of seven were mapped using the method of electrostimulation, before glioma removal.

Results: Distinct sites specifically involved in multiplication or subtraction were detected within the left AG, with a precise spatial distribution and overlapping. All the eloquent (somatosensory, language, and calculation) areas were surgically spared. Postoperatively, the patient had a transient complete deficit for arithmetic subtraction, without either multiplication or language disturbance. The tumour removal was complete.

Conclusions: These findings suggest: firstly, the usefulness of an intraoperative calculation mapping during the removal of a lesion involving the left dominant AG, to avoid permanent postoperative deficit of arithmetic processes while optimising the quality of tumour resection; secondly, the possible existence of a well ordered and dynamic anatomo-functional organisation for different components of calculation within the left AG.

  • acalculia
  • angular gyrus
  • functional brain mapping
  • cortical stimulations

Statistics from Altmetric.com

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Footnotes

  • Competing interests: none declared.