fMRI language task panel improves determination of language dominance

Abstract

A panel of fMRI language paradigms may be more accurate for evaluating partial epilepsy patients than a single task. A panel of tasks reduces the likelihood of nondiagnostic findings, improves interrater reliability, and helps confirm language laterality.

Comprehensive presurgical functional MRI language evaluation in adult patients with epilepsy

“…These and our results confirm the utility of fMRI in presurgical evaluation of patients with pharmacoresistant epilepsy and add to the growing body of evidence that fMRI can be used for presurgical language localization. Some of the more recent studies used a combination of fMRI tasks for evaluation of language functions in patients with epilepsy, and at least one study proposed using fMRI instead of the IAP [33,49]. Furthermore, one fMRI study using the SDTD task in patients with left temporal lobe epilepsy has already shown 100% sensitivity and 73% specificity in predicting significant naming decline after epilepsy surgery when language was lateralized to the left hemisphere, confirming the clinical utility of this fMRI task in presurgical evaluation of epilepsy surgery patients [26].…”

“…Bahn and colleagues reported that language lateralization with IAP and that with fMRI tasks agreed in all patients, but only the results of visual analysis were presented [13]. In contrast to the aforementioned studies, Galliard and colleagues used five different language fMRI tasks to determine language lateralization in 26 predominantly right-handed patients with epilepsy with left hemispheric seizure onset [33]. These authors reported significant agreement between the IAP and language lateralization with a panel of fMRI tasks, and they suggested that the panel may improve designation of language laterality in patients with epilepsy when compared with a single task.…”

“…These and other authors used various language fMRI tasks including semantic decision [14,16,21,[25][26][27], verb generation/verbal fluency [13,19,20,23,[28][29][30], word generation [15,18,22,24], and sentence reading [17,31]. Some studies have also reported the use of more than one fMRI paradigm for language localization and lateralization [10,12,13,29,32,33], but the results of these studies have been mixed, with some tasks showing good and some poor correlation with the results of IAP. It is still not clear whether performing more than one fMRI task will contribute to the presurgical evaluation of patients with epilepsy and whether different tasks (e.g., semantic decision and word production) are of similar importance in predicting language lateralization.…”

The use of neuroimaging to study behavior in patients with epilepsy

“…These studies have demonstrated prominent activations in left prefrontal areas (45,65-67), with less consistent activations in temporoparietal regions (65). Such data have led some experts to conclude that fMRI may be better suited for localizing expressive language areas within the frontal lobe than receptive language areas within temporal lobe regions ((68,69), but see (70,71)). Overall, results suggest approximately 90% concordance between fMRI and IAP lateralization in patients with TLE, with less impressive results in patients with extratemporal epilepsy (72).…”

“…In addition, there are data demonstrating that fMRI language activations complement electrocortical stimulation findings (73) and predict post-operative naming decline (74). Although no single fMRI task has emerged as superior for language lateralization, there is some evidence that a panel of tasks, including verbal fluency, reading comprehension, and auditory comprehension may provide the most reliable results (70).…”