Long-Range Auditory Functional Connectivity in Hearing Loss and Rehabilitation

Area of Science:

• Neuroscience
• Audiology
• Medical Imaging

Background:

• Age-related sensorineural hearing loss (HL) affects a significant portion of the global population.
• Hearing aids (HAs) are a common rehabilitation strategy for HL, but their effects on central auditory functional connectivity (FC) are not fully understood.
• HL is associated with changes in brain perfusion and connectivity, but the impact of rehabilitation requires further investigation.

Purpose of the Study:

• To investigate the impact of age-related sensorineural hearing loss (HL) on central auditory functional connectivity (FC).
• To examine the longitudinal effects of hearing aid (HA) use on brain FC and neurological function in patients with HL.
• To explore the relationship between HL severity, brain perfusion, FC, and cognitive performance.

Main Methods:

• A 3T MRI study involving 62 HL patients and 32 normal hearing (NH) subjects.
• Cross-sectional analysis at baseline and longitudinal analysis at 6-month follow-up for HL patients.
• Arterial spin labeling and resting-state fMRI (rs-fMRI) were used to assess regional perfusion and seed-based FC.

Main Results:

• At baseline, HL was linked to hypoperfusion in the right Heschl's gyrus and altered FC in posterior brain regions.
• Long-range FC in the precuneus negatively correlated with pure-tone and speech reception thresholds.
• Six months of HA usage showed increased FC in the right superior frontal gyrus (SFG) and decreased FC in the right middle temporal gyrus, with SFG changes correlating positively with executive function improvements.

Conclusions:

• Hearing aid (HA) rehabilitation may not reverse all HL-related neural effects but can induce neuroplastic changes.
• HA usage appears to retune long-range FC within the auditory system, offering potential neurological benefits.
• These findings highlight a neural link between peripheral auditory vulnerability and central brain function in HL patients, with potential for improved cognitive performance.