Abstracts

To evaluate the usefulness of functional MRI and Broca[apos]s area measurement for determining language dominance in patients with epilepsy. We performed functional MRI, Broca[apos]s area measurement and intracarotid amobarbital procedure (IAP) in 32 epilepsy patients. fMRI was obtained during noun generation task (NGT) and lexical decision task (LDT). A lateralization index of fMRI was calculated by (Left [ndash] Right / Left + Right) of activated pixel numbers in three hemispheric regions respectively (whole hemisphere, frontal lobe, and temporoparietal region). Broca[apos]s area and its mirror region in contralateral hemisphere were measured by manual tracing of left and right pars triangularis and pars opercularis, and asymmetry index of Broca[apos]s area was obtained by the same method. Their lateralization power of language dominance was compared with IAP. In IAP, 28 patients had left language dominance and four had right dominance. Compared to IAP results, language lateralization by fMRI signal in whole hemisphere was concordant to IAP in 96.9% using NGT and in 93.8% using LDT. Language lateralization by fMRI signal in frontal lobe was consistent with IAP in 93.8% using NGT and 87.8% using LDT. Language lateralization by fMRI signal in temporoparietal region was concordant to IAP in 93.8% using NGT and in 93.8% using LDT. False language lateralization of fMRI was observed in three cases. Language lateralization by measurement of Broca[apos]s area and its mirror region in contralateral hemisphere was concordant to IAP 73.3%. These results suggest that language lateralization with fMRI shows a high concordance with the results from the IAP and measurement of broca[apos]s area may be useful in addition to fMRI and IAP in language lateralization.