Patients (n=24) with aphasia after a left hemispheric stroke underwent naming assessment using the Boston Naming Test (BNT) and DTI at the acute and chronic time points. We analyzed DTI of right arcuate fasciculus (AF) and frontal aslant tracts (FAT). We used Wilcoxon rank sum test to evaluate structural lateralization patterns and partial Spearman correlation/multivariate generalized linear model to determine the role of right AF and FAT in naming recovery after controlling for age, education and lesion load. Results were corrected for multiple comparisons. 

On average, the structural integrity of left language pathways deteriorated more than their right homologues, such that there was rightward lateralization in the chronic stage. Regression/correlation analyses showed that greater preservation of tract integrity of right AF was associated with poorer naming recovery.

Our study provides preliminary evidence that preservation of right homologues of language pathways is associated with poor recovery of naming after a left hemispheric stroke, consistent with previous evidence that maintaining greater reliance on left hemisphere structures is associated with better language recovery.