Role of arcuate fasciculus in conduction aphasia in patients with ischemic stroke: A diffusion tensor tractography study

Abstract

Objective To investigate the role of arcuate fasciculus in conduction aphasia after ischemic stroke using magnetic resonance diffusion tensor imaging (DTI) technique. Methods Five patients with conduction aphasia after acute ischemic stroke (case group) and 5 patients without aphasia (control group) were selected. The DTI technique was used to detect the fractional anisotropy (FA) of Broca's area, Wernicke's area, and arcuate fasciculus. Results The FA values of Broca's area (0.341±0.018 vs.0.295±0.060; t=4.533, P=0.045), Wernicke's area (0.303±0.009 vs.0.243±0.011; t=6.556, P=0.022), and arcuate fiber bundle (0.646±0.020 vs.0.541±0.009; t=7.343, P=0.018) in the left hemisphere were significantly higher compared with their mirror areas in the control group. The FA values of Broca's area (0.315±0.015 vs.0.280±0.006; t=6.246, P=0.023), Wernicke's area (0.299±0.012 vs.0.239±0.022; t=4.576, P=0.025), and arcuate fiber bundle (0.226±0.016 vs.0.294±0.007; t=-12.590, P=0.006) in the left hemisphere were significantly higher compared with their mirror areas in the case group. There was no significant difference Broca's area (t=1.901, P=0.13) and Wernicke's area (t=2.092, P=0.105) in the left hemisphere between the case group and the control group, but the FA values of arcuate fasciculus in the left hemisphere in the case group was significantly lower compared with the control group (t=28.393, P<0.001). Conclusions For patients with conduction aphasia after acute ischemic stroke, the arcuate fasciculus has the left-dominant lateralization. Their conduction aphasia may be associated with the reduction and break of the arcuate fasciculus. Key words: Stroke; Brain Ischemia; Aphasia, Conduction; Diffusion Tensor Imaging; Neural Pathways