Investigating the role of structural connectivity in the individuals with moderate hearing loss

Abstract

Hearing loss has been identified as a risk factor for cognitive decline. The processing of auditory information relies on a well-connected neuronal network. Previous studies have found white matter abnormalities in individuals with hearing loss, but the structural connectivity and microstructural properties of white matter in individuals with moderate hearing loss remain unclear.

To examine the integrity of white matter, identify vulnerable structural connectivity, and assess network topology, we examined major white matter tracts in elderly individuals with moderate hearing loss (MHL) (>30 dB) and compared them to age-matched controls with good hearing (GH).

We observed that the fractional anisotropy of the right corticospinal tract and left superior longitudinal fasciculus – parietal was higher in subjects with MHL. Additionally, we identified a disrupted network centered on the left putamen in MHL, involving eight brain regions. Network topology analysis showed reduced betweenness centrality and small-world network in MHL. Interestingly, the fractional anisotropy of the forceps major tract and left uncinate tracts were correlated with hearing status.

Our findings suggest that MHL is associated with putamen-centered disruptions in structural connectivity. The increased fractional anisotropy of the right corticospinal tract may be a compensatory mechanism, as it projects fibers to the right putamen. Overall, these results provide valuable insights into the impact of hearing loss on white matter integrity and may inform the development of new treatments to prevent its progression.