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Usage of fMRI for pre-surgical planning in brain tumor and vascular lesion patients: task and statistical threshold effects on language lateralization.

Nadkarni TN, Andreoli MJ, Nair VA, Yin P, Young BM, Kundu B, Pankratz J, Radtke A, Holdsworth R, Kuo JS, Field AS, Baskaya MK, Moritz CH, Meyerand ME, Prabhakaran V - Neuroimage Clin (2014)

Bottom Line: We investigated the effect of varying the statistical thresholds as well as the type of language tasks on functional activation patterns and language lateralization.Our results suggest that the type of task and the applied statistical threshold influence LI and that the threshold effects on LI may be task-specific.Thus identifying critical functional regions and computing LIs should be conducted on an individual subject basis, using a continuum of threshold values with different tasks to provide the most accurate information for surgical planning to minimize post-operative language deficits.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, University of Wisconsin - Madison, USA.

ABSTRACT

Background and purpose: Functional magnetic resonance imaging (fMRI) is a non-invasive pre-surgical tool used to assess localization and lateralization of language function in brain tumor and vascular lesion patients in order to guide neurosurgeons as they devise a surgical approach to treat these lesions. We investigated the effect of varying the statistical thresholds as well as the type of language tasks on functional activation patterns and language lateralization. We hypothesized that language lateralization indices (LIs) would be threshold- and task-dependent.

Materials and methods: Imaging data were collected from brain tumor patients (n = 67, average age 48 years) and vascular lesion patients (n = 25, average age 43 years) who received pre-operative fMRI scanning. Both patient groups performed expressive (antonym and/or letter-word generation) and receptive (tumor patients performed text-reading; vascular lesion patients performed text-listening) language tasks. A control group (n = 25, average age 45 years) performed the letter-word generation task.

Results: Brain tumor patients showed left-lateralization during the antonym-word generation and text-reading tasks at high threshold values and bilateral activation during the letter-word generation task, irrespective of the threshold values. Vascular lesion patients showed left-lateralization during the antonym and letter-word generation, and text-listening tasks at high threshold values.

Conclusion: Our results suggest that the type of task and the applied statistical threshold influence LI and that the threshold effects on LI may be task-specific. Thus identifying critical functional regions and computing LIs should be conducted on an individual subject basis, using a continuum of threshold values with different tasks to provide the most accurate information for surgical planning to minimize post-operative language deficits.

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Average hemispheric LIs in left frontal tumor patients (n = 27) and left non-frontal tumor patients (n = 15) at different threshold values (t < 2.0, t < 2.6, t < 3.5, t < 4.0) performing the letter-word generation (LWG) task.
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f0020: Average hemispheric LIs in left frontal tumor patients (n = 27) and left non-frontal tumor patients (n = 15) at different threshold values (t < 2.0, t < 2.6, t < 3.5, t < 4.0) performing the letter-word generation (LWG) task.

Mentions: The average LIs for the tumor patient group that performed the AWG task showed bilateral activation at low threshold values (ts < 2.6), but left-lateral activation at high threshold values (ts < 4.0) (Table 6 and Fig. 3, top). In contrast, despite varying the threshold, bilateral activation was maintained during the LWG task (Fig. 3, top). Also all of our patients had brain tumors in the left hemisphere with no differences between frontal and non-frontal tumor patients with both demonstrating bilateral activation during the LWG task (Fig. 4).


Usage of fMRI for pre-surgical planning in brain tumor and vascular lesion patients: task and statistical threshold effects on language lateralization.

Nadkarni TN, Andreoli MJ, Nair VA, Yin P, Young BM, Kundu B, Pankratz J, Radtke A, Holdsworth R, Kuo JS, Field AS, Baskaya MK, Moritz CH, Meyerand ME, Prabhakaran V - Neuroimage Clin (2014)

Average hemispheric LIs in left frontal tumor patients (n = 27) and left non-frontal tumor patients (n = 15) at different threshold values (t < 2.0, t < 2.6, t < 3.5, t < 4.0) performing the letter-word generation (LWG) task.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4310930&req=5

f0020: Average hemispheric LIs in left frontal tumor patients (n = 27) and left non-frontal tumor patients (n = 15) at different threshold values (t < 2.0, t < 2.6, t < 3.5, t < 4.0) performing the letter-word generation (LWG) task.
Mentions: The average LIs for the tumor patient group that performed the AWG task showed bilateral activation at low threshold values (ts < 2.6), but left-lateral activation at high threshold values (ts < 4.0) (Table 6 and Fig. 3, top). In contrast, despite varying the threshold, bilateral activation was maintained during the LWG task (Fig. 3, top). Also all of our patients had brain tumors in the left hemisphere with no differences between frontal and non-frontal tumor patients with both demonstrating bilateral activation during the LWG task (Fig. 4).

Bottom Line: We investigated the effect of varying the statistical thresholds as well as the type of language tasks on functional activation patterns and language lateralization.Our results suggest that the type of task and the applied statistical threshold influence LI and that the threshold effects on LI may be task-specific.Thus identifying critical functional regions and computing LIs should be conducted on an individual subject basis, using a continuum of threshold values with different tasks to provide the most accurate information for surgical planning to minimize post-operative language deficits.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, University of Wisconsin - Madison, USA.

ABSTRACT

Background and purpose: Functional magnetic resonance imaging (fMRI) is a non-invasive pre-surgical tool used to assess localization and lateralization of language function in brain tumor and vascular lesion patients in order to guide neurosurgeons as they devise a surgical approach to treat these lesions. We investigated the effect of varying the statistical thresholds as well as the type of language tasks on functional activation patterns and language lateralization. We hypothesized that language lateralization indices (LIs) would be threshold- and task-dependent.

Materials and methods: Imaging data were collected from brain tumor patients (n = 67, average age 48 years) and vascular lesion patients (n = 25, average age 43 years) who received pre-operative fMRI scanning. Both patient groups performed expressive (antonym and/or letter-word generation) and receptive (tumor patients performed text-reading; vascular lesion patients performed text-listening) language tasks. A control group (n = 25, average age 45 years) performed the letter-word generation task.

Results: Brain tumor patients showed left-lateralization during the antonym-word generation and text-reading tasks at high threshold values and bilateral activation during the letter-word generation task, irrespective of the threshold values. Vascular lesion patients showed left-lateralization during the antonym and letter-word generation, and text-listening tasks at high threshold values.

Conclusion: Our results suggest that the type of task and the applied statistical threshold influence LI and that the threshold effects on LI may be task-specific. Thus identifying critical functional regions and computing LIs should be conducted on an individual subject basis, using a continuum of threshold values with different tasks to provide the most accurate information for surgical planning to minimize post-operative language deficits.

Show MeSH
Related in: MedlinePlus