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Language Lateralization in Temporal Lobe Epilepsy: A Comparison between f MRI and the Wada Test
Author(s) -
Benke Thomas,
Köylü Bülent,
Visani Pamela,
Karner Elfriede,
Brenneis Christian,
Bartha Lisa,
Trinka Eugen,
Trieb Thomas,
Felber Stephan,
Bauer Gerhard,
Chemelli Andreas,
Willmes Klaus
Publication year - 2006
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/j.1528-1167.2006.00549.x
Subject(s) - laterality , wada test , lateralization of brain function , psychology , audiology , temporal lobe , concordance , epilepsy , amobarbital , epilepsy surgery , cognitive psychology , neuroscience , medicine
Summary: Purpose: Recent studies have claimed that language functional magnetic resonance imaging ( f MRI) can identify language lateralization in patients with temporal lobe epilepsy (TLE) and that f MRI‐based findings are highly concordant with the conventional assessment procedure of speech dominance, the intracarotid amobarbital test (IAT). Methods: To establish the power of language f MRI to detect language lateralization during presurgical assessment, we compared the findings of a semantic decision paradigm with the results of a standard IAT in 68 patients with chronic intractable right and left temporal lobe epilepsy (rTLE, n = 28; lTLE, n = 40) who consecutively underwent a presurgical evaluation program. The patient group also included 14 (20.6%) subjects with atypical (bilateral or right hemisphere) speech. Four raters used a visual analysis procedure to determine the laterality of speech‐related activation individually for each patient. Results: Overall congruence between f MRI‐based laterality and the laterality quotient of the IAT was 89.3% in rTLE and 72.5% in lTLE patients. Concordance was best in rTLE patients with left speech. In lTLE patients, language f MRI identified atypical, right hemisphere speech dominance in every case, but missed left hemisphere speech dominance in 17.2%. Frontal activations had higher concordance with the IAT than did activations in temporoparietal or combined regions of interest (ROIs). Because of methodologic problems, recognition of bilateral speech was difficult. Conclusions: These data provide evidence that language f MRI as used in the present study has limited correlation with the IAT, especially in patients with lTLE and with mixed speech dominance. Further refinements regarding the paradigms and analysis procedures will be needed to improve the contribution of language f MRI for presurgical assessment.