Brain morphological changes in acquired hearing loss: A surface-based morphometry study

Area of Science:

• Neuroscience
• Radiology
• Otolaryngology

Background:

• Auditory deprivation leads to neuroplasticity and structural brain changes.
• Understanding these changes is vital for effective auditory rehabilitation.
• Bilateral deafness (BD) involves significant hearing loss, impacting auditory pathways.

Purpose of the Study:

• To investigate brain morphological alterations in patients with bilateral deafness (BD).
• To examine the relationship between cortical thickness (CT), cortical volume (CV), duration of deafness (DoD), and hearing aid use (DoHA).

Main Methods:

• Retrospective analysis of 3D T1-weighted MRI data from 47 BD patients and 73 normal hearing (NH) controls.
• Surface-based morphometry (SBM) using FreeSurfer for CT and CV analysis.
• General linear models and partial correlation analyses to assess associations with DoD and DoHA.

Main Results:

• BD patients exhibited reduced CT in superior temporal and lateral occipital cortices compared to NH controls.
• Significant CV reductions were observed in bilateral superior temporal gyri, superior parietal, and lateral occipital cortices in BD patients.
• Longer duration of hearing aid use (DoHA) positively correlated with right superior temporal gyrus CT.

Conclusions:

• Long-term bilateral deafness is linked to widespread cortical atrophy, affecting auditory and sensory integration regions.
• Sustained hearing aid use may help preserve cortical structure in individuals with hearing loss.
• Timely auditory rehabilitation could potentially slow neurodegeneration and mitigate cognitive risks associated with hearing loss.