fMRI language task panel improves determination of language dominance.
BACKGROUND
fMRI language tasks reliably identify language areas in presurgical epilepsy patients, but activation using single paradigms may disagree with the intracarotid amobarbital test (IAT).


OBJECTIVE
To determine whether a panel of fMRI tasks targeting different aspects of language processing increases accuracy in determining hemisphere language dominance.


METHODS
Twenty-six patients age 12 to 56 years, predominantly with temporal lobe epilepsy, were studied using whole-brain 1.5 T fMRI (echo planar imaging, blood oxygenation level-dependent) with three task categories using a block design: verbal fluency, reading comprehension, and auditory comprehension. fMRI t maps were visually rated at three thresholds. All patients had assessment of language lateralization by IAT.


RESULTS
fMRI showed left dominance in 21 patients, right dominance in 2, and bilateral activation in 2; raters disagreed over a left vs right bilateral rating in 1 patient. There was full agreement between IAT and fMRI in 21 of 25 patients (IAT failed in 1). In three instances of partial disparity with IAT, the fMRI panel showed consistent findings across raters. Agreement between raters was excellent (partial disagreement in only one patient); the panel of tasks was superior to any single task for interrater agreement (Cramer V 0.93 [range 0.91 to 1.0] vs 0.72 [range 0.60 to 0.86]).


CONCLUSIONS
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.
Gaillard
W D
WD
Department of Neurology, Children's National Medical Center, George Washington University School of Medicine, 111 Michigan Ave. NW, Washington, DC 20010, USA. gaillardw@ninds.nih.gov
Balsamo
L
L
Xu
B
B
McKinney
C
C
Papero
P H
PH
Weinstein
S
S
Conry
J
J
Pearl
P L
PL
Sachs
B
B
Sato
S
S
Vezina
L G
LG
Frattali
C
C
Theodore
W H
WH
D000293:Adolescent; D000328:Adult; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D002648:Child; D004292:Dominance, Cerebral / Q000502:physiology*; D004827:Epilepsy / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007802:Language; D007807:Language Tests / Q000592:standards*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods*; D015203:Reproducibility of Results; D013067:Speech Perception / Q000502:physiology; D013702:Temporal Lobe / Q000473:pathology / Q000503:physiopathology; D014705:Verbal Behavior / Q000502:physiology*