Agraphia after awake surgery for brain tumor: new insights into the anatomo-functional network of writing

Scarone, Pietro; Gatignol, Peggy; Guillaume, Sophie; Denvil, Dominique; Capelle, Laurent; Duffau, Hugues

doi:10.1016/j.surneu.2008.10.074

« Previous Next »Surgical Neurology
Volume 72, Issue 3 , Pages 223-241, September 2009

Agraphia after awake surgery for brain tumor: new insights into the anatomo-functional network of writing

Pietro Scarone, MD
- Department of Neurosurgery, Hôpital Foch, Suresnes, France 92150
Peggy Gatignol, ST
- Laboratoire de la Cognition et du Comportement, UMR 8189 (CNRS/ Université de Paris V René Descartes), Institut de Psychologie, Boulogne Billancourt, France 92774
Sophie Guillaume, MD
- Department of Neurology, Hôpital Andre Mignot, Versailles, France 78150
Dominique Denvil, MD
- Department of Neurosurgery, Hôpital de la Salpêtrière, Paris, France 75013
Laurent Capelle, MD
- Department of Neurosurgery, Hôpital de la Salpêtrière, Paris, France 75013
- UMR-S678 Inserm, UPMC, Hôpital de la Salpêtrière, Paris, France 75651
Hugues Duffau, MD, PhD
- Laboratoire de la Cognition et du Comportement, UMR 8189 (CNRS/ Université de Paris V René Descartes), Institut de Psychologie, Boulogne Billancourt, France 92774
- UMR-S678 Inserm, UPMC, Hôpital de la Salpêtrière, Paris, France 75651
- Department of Neurosurgery, Hôpital Gui de Chauliac, CHU de Montpellier, Montpellier, France 34295
- Corresponding author. Department of Neurosurgery, Hôpital Gui de Chauliac, CHU de Montpellier, 34295 Montpellier Cedex 5, France. Tel.: +33 (0)4 67 33 02 90; fax: +33 (0)4 67 33 75 57.

Received 10 August 2008; received in revised form 21 October 2008; accepted 31 October 2008. published online 24 July 2009.

Abstract

Background

Controversy still exists about neural basis underlying writing and its relation with the sites subserving oral language. Our objective is to study functional areas involved in writing network, based on the observations of different postoperative writing disorders in a population of patients without preoperative agraphia.

Methods

We analyzed the postoperative agraphia profiles in 15 patients who underwent surgery for cerebral LGGs in functional language areas, using electrical mapping under local anesthesia. These profiles were then correlated to the sites of the lesions, shown by preoperative cerebral imaging.

Results

Our findings showed that (1) spoken language and writing functions could be dissociated, and that (2) writing is subserved, at least partially, by a network of 5 areas located in the dominant hemisphere for language: the superior parietal region, the supramarginalis gyrus, the second and third frontal convolutions, the supplementary motor area, and the insula. Each of these areas seems to have a different role in writing, which will be detailed in this article. However, among the patients, only those with lesions of the supplementary motor area did not recover from agraphia in the postoperative period (in 50% of cases).

Conclusions

On the basis of these results, and in the light of the recent literature, we discuss the relevance of each area in this anatomo-functional network as well as the clinical implications of such better knowledge of the neural basis of writing, especially for brain surgery and functional rehabilitation.

Abbreviations: LGGs, low-grade gliomas, BDAE, Boston Diagnostic Aphasia Examination, MRI, magnetic resonance imaging, fMRI, functional magnetic resonance imaging, PET, positron emission tomography, DES, direct electrical stimulation, BA, Brodmann area, SMG, supramarginal gyrus, SMA, supplementary motor area, F2, middle frontal gyrus, F3, inferior frontal gyrus, SPL, superior parietal lobule