Evaluation of White Matter Integrity by Using Diffusion Tensor Imaging in Patients with Presbycusis

This study aims to evaluate white matter microstructure integrity in patients diagnosed with presbycusis (age-related hearing loss) using diffusion tensor imaging (DTI) and to investigate the relationship between DTI parameters and hearing loss severity.

Patients aged 50 and above with presbycusis (pure-tone average [PTA] ≥20dB) were categorized as mild (PTA 20-34dB), moderate (PTA 35-49dB), or severe (PTA ≥50dB). Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were measured in 16 white matter regions. The relationship between DTI parameters and speech discrimination scores was assessed using multiple linear regression, adjusting for age, sex, and vascular risk profile.

The study included 148 patients (mild=32, moderate=84, severe=32). DTI analysis showed significantly lower FA in the left cingulum (p = 0.001) and right IFOF (p = 0.003) in the severe group compared to the mild and moderate groups, while RD in the left cingulum was higher in the severe group (p = 0.006). The mild group exhibited significantly lower left IFOF RD (p < 0.001) compared to the moderate and severe groups, and significantly lower left cingulum body MD (p = 0.004) compared to the severe group. Significant associations were found between speech discrimination scores and DTI parameters, including right hippocampal cingulum MD (p = 0.030), left IFOF RD (p = 0.033), right Heschl's gyrus MD (p = 0.018), and AD (p = 0.008).

This study demonstrated significant alterations in white matter microstructure across different severities of presbycusis. Further research is needed to fully understand the cognitive and central auditory dysfunctions associated with presbycusis.