[Correlation of diffusion tensor imaging between the cerebral cortex and speech discrimination in presbycusis]

To investigate the relationship between pure-tone average (PTA), the fractional anisotropy (FA) of the auditory pathway, cognitive cortex and auditory cortex in presbycusis.Twenty-five elderly subjects with presbycusis were participated in the study. PTA, speech discrimination abilities were evaluated in each subject. Diffusion tensor imaging (DTI) was applied to access the FA of the IC, the superior frontal gyrus and the Heschl's gyrus. Compare the difference between two sides of the values of FA in the three areas. Bivariate correlation analysis was performed to evaluate the effects of PTA and FA of the inferior colliculus (IC), the superior frontal gyrus and the Heschl's gyrus on speech discrimination abilities.There were no significant differences between the left and right side of the inferior colliculus (P0.05). Higher FA values were recorded at the left side of the Heschl's gyrus and the superior frontal gyrus (P0.05). Both PTA and the FA of the superior frontal gyrus have a negative association with speech discrimination abilities (P0.01, P0.05), while the FA of the Heschl's gyrus has a positive association with speech discrimination abilities (P0.05).Our findings indicated that the speech discrimination abilities of the elderly is not only related to the peripheral auditory function, but also to the central auditory and cognitive function.