Journal of Neurology

, 256:382

Is the left uncinate fasciculus essential for language?

A cerebral stimulation study
  • H. Duffau
  • P. Gatignol
  • S. Moritz-Gasser
  • E. Mandonnet

DOI: 10.1007/s00415-009-0053-9

Cite this article as:
Duffau, H., Gatignol, P., Moritz-Gasser, S. et al. J Neurol (2009) 256: 382. doi:10.1007/s00415-009-0053-9


Despite a better understanding of the anatomy of the uncinate fasciculus (UF), its function remains poorly known. Our aim was to study the exact role of UF in language, and the possible existence of parallel distributed language networks within the “ventral stream”, underlaid by distinct subcortical tracts – namely the inferior occipito-temporal fasciculus (IOF) and UF.

We report a series of 13 patients operated on awake for a glioma involving the left anterior temporal lobe or the orbitofrontal area. We used intraoperative electrostimulation, to perform accurate and reliable anatomofunctional correlations both at cortical and subcortical levels. Using postoperative MRI, we correlated these functional findings with the anatomical locations of the sites where language disturbances were elicited by stimulation.

Intraoperative cortical stimulation found perilesional language sites in all cases. Subcortically, semantic paraphasia were induced in the 13 patients by stimulating the IOF, and phonological paraphasia were generated in 6 patients by stimulating the arcuate fasciculus. Interestingly, subcortical stimulation never elicited any language disturbances when performed at the level of the UF. Moreover, after a transient postoperative language deficit, all patients recovered, despite the removal of at least one part of the UF, as confirmed by control MRI.

We suggest that UF is not systematically essential for language. It can be explained by the fact that the “semantic ventral stream” might be constituted by at least two parallel pathways, i. e. a direct pathway underlaid by the IOF, crucial for language semantics, and an indirect pathway subserved by UF, which can be functionally compensated. However, we have to underline the fact not all language functions can be probed during surgery, and that more sensitive tasks have now to be added.

Key words

languageuncinate fasciculusdirect electrical stimulationconnectivitybrain mapping

Copyright information

© Steinkopff-Verlag 2009

Authors and Affiliations

  • H. Duffau
    • 1
    • 2
  • P. Gatignol
    • 2
  • S. Moritz-Gasser
    • 3
  • E. Mandonnet
    • 4
  1. 1.Dept. of Neurosurgery, Hôpital Gui de ChauliacCHU MontpellierMontpellierFrance
  2. 2.Laboratoire de Psychologie et de, Neurosciences CognitivesCNRS UMR 8189, Université René DescartesParis VFrance
  3. 3.Dept. of Neurology, Hôpital Gui de ChauliacCHU MontpellierMontpellierFrance
  4. 4.INSERM U678Hôpital de la SalpêtrièreParis, Cedex 13France