Robust localization and lateralization of human language function: an optimized clinical functional magnetic resonance imaging protocol.
An optimized clinical functional magnetic resonance imaging (fMRI) protocol with a total scanning time of 8 min is presented that localizes Broca's and Wernicke's areas robustly and determines hemispheric dominance. Language function was visualized using two different sentence generation (SG) and word generation (WG) tasks. Block designed blood oxygenation level dependent (BOLD) fMRI was applied in 14 right-handed volunteers at 1.5 T during visual stimulation. BOLD-clusters were assessed individually for anatomical localization. Reference data are provided for the maximum correlation of the measured BOLD-signal time course to the applied reference function (r(max)), for the maximum relative signal change (dS%), cluster size and Euklidian coordinates of Broca and Wernicke activation and of the anatomical homologues in the right hemispheres. Statistical means and a lateralization index (LI) were calculated. Broca activation focussed on the inferior frontal gyrus, and Wernicke activation on the superior temporal, supramarginal or middle temporal gyri. Mean BOLD-signals for Broca ranged from 1.53% (SG) to 2.56% (WG), and for Wernicke from 1.47% (SG) to 1.80% (WG). LI indicated left language dominance. The data provided further evidence for the high anatomical variability of language areas, which underlined the relevance of an individual language localization and lateralization prior to brain surgery.
Stippich
Christoph
C
Department of Neurology, University of Heidelberg Medical Center, Im Neuenheimer Feld 400, D-69120 Heidelberg, Germany. christoph_stippich@med.uni-heidelberg.de
Mohammed
Jamila
J
Kress
Bodo
B
Hähnel
Stefan
S
Günther
Julia
J
Konrad
Florian
F
Sartor
Klaus
K
D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D013702:Temporal Lobe / Q000502:physiology