A comparison of brain activity associated with language production in brain tumor patients with left and right sided language laterality

J. M. Jansma*, N. Ramsey, G.J.M. Rutten

*Corresponding author for this work

Research output: Contribution to journalLiterature reviewScientificpeer-review

Abstract

Aim. Language dominance is an important factor for clinical decision making in brain tumor surgery. Functional MM can provide detailed information about the organization of language in the brain. One often used measure derived from fMRI data is the laterality index (LI). The LI is typically based on the ratio between left and right brain activity in a specific region associated with language. Nearly all fMRI language studies show language-related activity in both hemispheres, and as a result the LI shows a large range of values. The clinical significance of the variation in language laterality as measured with the LI is still under debate. In this study, we tested two hypotheses in relation to the LI, measured in Broca's region, and it's right hemisphere homologue: 1: the level of activity in Broca's and it's right hemisphere homologue is mirrored for subjects with an equal but opposite LI; 2: the whole brain language activation pattern differs between subjects with an equal but opposite LI.

Methods. One hundred sixty-three glioma and meningioma patients performed a verb generation task as part of a standard clinical protocol. We calculated the LI in the pars orbitalis, pars triangularis and pars opercularis of the left inferior frontal gyrus, referred to as Broca's region from here on. In our database, 21 patients showed right lateralized activity, with a moderate average level (-0.32). A second group of 21 patients was selected from the remaining group, for equal but opposite LI (0.32). We compared the level and distribution of activity associated with language production in the left and right hemisphere in these two groups.

Results. Patients with left sided laterality showed a significantly higher level of activity in Broca's region than the patients with right sided laterality. However, both groups showed no difference in level of activity in Broca's homologue region in the right hemisphere. Also, we did not see any difference in the pattern of activity between patients with left-sided and right-sided laterality, outside of the regions used to calculate the LI.

Conclusion. Our results indicate that an equal but opposite moderate LI is not associated with mirrored left and right hemisphere levels of activity in Broca's region and its right hemisphere homologue, nor in any other region of the brain. These results suggest that the LI as measured with fMRI should be interpreted with caution as a measure of organization of language in the brain. For moderate LI values based on Broca's region, it appears that variation in the LI value is predominantly a result of variation in the level of activity in the left hemisphere. Our results suggest that several factors may contribute to variation in the level of laterality, that may be unrelated to hemispheric dominance, such as task performance as well as efficiency of language processing, by affecting the level of activity in Broca's region.

Original languageEnglish
Pages (from-to)327-335
Number of pages9
JournalJournal of Neurosurgical Sciences
Volume59
Issue number4
Publication statusPublished - Dec 2015

Keywords

  • Magnetic resonance imaging
  • Brain neoplasms
  • Functional laterality
  • Neurosurgery
  • FUNCTIONAL MRI
  • BROCAS AREA
  • PREFRONTAL CORTEX
  • FMRI
  • DOMINANCE
  • TASK
  • REPRODUCIBILITY
  • REGISTRATION
  • EFFICIENCY
  • SURGERY

Cite this

@article{2ab499f4ad7145c2b3ad5fbfcabf2a4f,
title = "A comparison of brain activity associated with language production in brain tumor patients with left and right sided language laterality",
abstract = "Aim. Language dominance is an important factor for clinical decision making in brain tumor surgery. Functional MM can provide detailed information about the organization of language in the brain. One often used measure derived from fMRI data is the laterality index (LI). The LI is typically based on the ratio between left and right brain activity in a specific region associated with language. Nearly all fMRI language studies show language-related activity in both hemispheres, and as a result the LI shows a large range of values. The clinical significance of the variation in language laterality as measured with the LI is still under debate. In this study, we tested two hypotheses in relation to the LI, measured in Broca's region, and it's right hemisphere homologue: 1: the level of activity in Broca's and it's right hemisphere homologue is mirrored for subjects with an equal but opposite LI; 2: the whole brain language activation pattern differs between subjects with an equal but opposite LI.Methods. One hundred sixty-three glioma and meningioma patients performed a verb generation task as part of a standard clinical protocol. We calculated the LI in the pars orbitalis, pars triangularis and pars opercularis of the left inferior frontal gyrus, referred to as Broca's region from here on. In our database, 21 patients showed right lateralized activity, with a moderate average level (-0.32). A second group of 21 patients was selected from the remaining group, for equal but opposite LI (0.32). We compared the level and distribution of activity associated with language production in the left and right hemisphere in these two groups.Results. Patients with left sided laterality showed a significantly higher level of activity in Broca's region than the patients with right sided laterality. However, both groups showed no difference in level of activity in Broca's homologue region in the right hemisphere. Also, we did not see any difference in the pattern of activity between patients with left-sided and right-sided laterality, outside of the regions used to calculate the LI.Conclusion. Our results indicate that an equal but opposite moderate LI is not associated with mirrored left and right hemisphere levels of activity in Broca's region and its right hemisphere homologue, nor in any other region of the brain. These results suggest that the LI as measured with fMRI should be interpreted with caution as a measure of organization of language in the brain. For moderate LI values based on Broca's region, it appears that variation in the LI value is predominantly a result of variation in the level of activity in the left hemisphere. Our results suggest that several factors may contribute to variation in the level of laterality, that may be unrelated to hemispheric dominance, such as task performance as well as efficiency of language processing, by affecting the level of activity in Broca's region.",
keywords = "Magnetic resonance imaging, Brain neoplasms, Functional laterality, Neurosurgery, FUNCTIONAL MRI, BROCAS AREA, PREFRONTAL CORTEX, FMRI, DOMINANCE, TASK, REPRODUCIBILITY, REGISTRATION, EFFICIENCY, SURGERY",
author = "Jansma, {J. M.} and N. Ramsey and G.J.M. Rutten",
year = "2015",
month = "12",
language = "English",
volume = "59",
pages = "327--335",
journal = "Journal of Neurosurgical Sciences",
issn = "0390-5616",
publisher = "EDIZIONI MINERVA MEDICA",
number = "4",

}

A comparison of brain activity associated with language production in brain tumor patients with left and right sided language laterality. / Jansma, J. M.; Ramsey, N.; Rutten, G.J.M.

In: Journal of Neurosurgical Sciences, Vol. 59, No. 4, 12.2015, p. 327-335.

Research output: Contribution to journalLiterature reviewScientificpeer-review

TY - JOUR

T1 - A comparison of brain activity associated with language production in brain tumor patients with left and right sided language laterality

AU - Jansma, J. M.

AU - Ramsey, N.

AU - Rutten, G.J.M.

PY - 2015/12

Y1 - 2015/12

N2 - Aim. Language dominance is an important factor for clinical decision making in brain tumor surgery. Functional MM can provide detailed information about the organization of language in the brain. One often used measure derived from fMRI data is the laterality index (LI). The LI is typically based on the ratio between left and right brain activity in a specific region associated with language. Nearly all fMRI language studies show language-related activity in both hemispheres, and as a result the LI shows a large range of values. The clinical significance of the variation in language laterality as measured with the LI is still under debate. In this study, we tested two hypotheses in relation to the LI, measured in Broca's region, and it's right hemisphere homologue: 1: the level of activity in Broca's and it's right hemisphere homologue is mirrored for subjects with an equal but opposite LI; 2: the whole brain language activation pattern differs between subjects with an equal but opposite LI.Methods. One hundred sixty-three glioma and meningioma patients performed a verb generation task as part of a standard clinical protocol. We calculated the LI in the pars orbitalis, pars triangularis and pars opercularis of the left inferior frontal gyrus, referred to as Broca's region from here on. In our database, 21 patients showed right lateralized activity, with a moderate average level (-0.32). A second group of 21 patients was selected from the remaining group, for equal but opposite LI (0.32). We compared the level and distribution of activity associated with language production in the left and right hemisphere in these two groups.Results. Patients with left sided laterality showed a significantly higher level of activity in Broca's region than the patients with right sided laterality. However, both groups showed no difference in level of activity in Broca's homologue region in the right hemisphere. Also, we did not see any difference in the pattern of activity between patients with left-sided and right-sided laterality, outside of the regions used to calculate the LI.Conclusion. Our results indicate that an equal but opposite moderate LI is not associated with mirrored left and right hemisphere levels of activity in Broca's region and its right hemisphere homologue, nor in any other region of the brain. These results suggest that the LI as measured with fMRI should be interpreted with caution as a measure of organization of language in the brain. For moderate LI values based on Broca's region, it appears that variation in the LI value is predominantly a result of variation in the level of activity in the left hemisphere. Our results suggest that several factors may contribute to variation in the level of laterality, that may be unrelated to hemispheric dominance, such as task performance as well as efficiency of language processing, by affecting the level of activity in Broca's region.

AB - Aim. Language dominance is an important factor for clinical decision making in brain tumor surgery. Functional MM can provide detailed information about the organization of language in the brain. One often used measure derived from fMRI data is the laterality index (LI). The LI is typically based on the ratio between left and right brain activity in a specific region associated with language. Nearly all fMRI language studies show language-related activity in both hemispheres, and as a result the LI shows a large range of values. The clinical significance of the variation in language laterality as measured with the LI is still under debate. In this study, we tested two hypotheses in relation to the LI, measured in Broca's region, and it's right hemisphere homologue: 1: the level of activity in Broca's and it's right hemisphere homologue is mirrored for subjects with an equal but opposite LI; 2: the whole brain language activation pattern differs between subjects with an equal but opposite LI.Methods. One hundred sixty-three glioma and meningioma patients performed a verb generation task as part of a standard clinical protocol. We calculated the LI in the pars orbitalis, pars triangularis and pars opercularis of the left inferior frontal gyrus, referred to as Broca's region from here on. In our database, 21 patients showed right lateralized activity, with a moderate average level (-0.32). A second group of 21 patients was selected from the remaining group, for equal but opposite LI (0.32). We compared the level and distribution of activity associated with language production in the left and right hemisphere in these two groups.Results. Patients with left sided laterality showed a significantly higher level of activity in Broca's region than the patients with right sided laterality. However, both groups showed no difference in level of activity in Broca's homologue region in the right hemisphere. Also, we did not see any difference in the pattern of activity between patients with left-sided and right-sided laterality, outside of the regions used to calculate the LI.Conclusion. Our results indicate that an equal but opposite moderate LI is not associated with mirrored left and right hemisphere levels of activity in Broca's region and its right hemisphere homologue, nor in any other region of the brain. These results suggest that the LI as measured with fMRI should be interpreted with caution as a measure of organization of language in the brain. For moderate LI values based on Broca's region, it appears that variation in the LI value is predominantly a result of variation in the level of activity in the left hemisphere. Our results suggest that several factors may contribute to variation in the level of laterality, that may be unrelated to hemispheric dominance, such as task performance as well as efficiency of language processing, by affecting the level of activity in Broca's region.

KW - Magnetic resonance imaging

KW - Brain neoplasms

KW - Functional laterality

KW - Neurosurgery

KW - FUNCTIONAL MRI

KW - BROCAS AREA

KW - PREFRONTAL CORTEX

KW - FMRI

KW - DOMINANCE

KW - TASK

KW - REPRODUCIBILITY

KW - REGISTRATION

KW - EFFICIENCY

KW - SURGERY

M3 - Literature review

VL - 59

SP - 327

EP - 335

JO - Journal of Neurosurgical Sciences

JF - Journal of Neurosurgical Sciences

SN - 0390-5616

IS - 4

ER -