HealthDay News — Right hemisphere white matter integrity predicts speech fluency in patients in the chronic phase of left hemisphere stroke with aphasia, according to a study published in Neurology.
Ethan Pani, from the Beth Israel Deaconess Medical Center in Boston, and colleagues conducted a cross-sectional study to examine the contribution of the right hemisphere’s speech-relevant white matter regions and interhemispheric connectivity to speech fluency in patients with left hemisphere stroke with aphasia. The authors correlated fractional anisotropy (FA) of white matter regions underlying the right middle temporal gyrus (MTG), precentral gyrus (PreCG), pars opercularis (IFGop) and triangularis (IFGtri) of the inferior frontal gyrus, and the corpus callosum (CC) with measures of speech fluency.
The researchers found that speech fluency was significantly predicted by FA values for the right MTG, PreCG, and IFGop, but not by IFGtri and superior parietal lobule. The best model for predicting speech fluency was combining FA of the significant right hemisphere lesions with the lesion load of the left arcuate fasciculus. Speech fluency was also associated with FA of CC fibers connecting left and right supplementary motor areas (SMA). Patients had significantly higher FA of the right IFGop and PreCG and lower FA of a whole CC region of interest (ROI) and the CC-SMA ROI versus controls.
“This may indicate premorbid anatomical variability beneficial for recovery or be the result of post-stroke remodeling,” the authors write.