Relationship between Hearing Loss and Dementia Differs According to the Underlying Mechanism

Area of Science:

• Neurology
• Neuroimaging
• Audiology

Background:

• The relationship between hearing loss (HL) and cognitive impairment (CI) mechanisms is not fully understood.
• Clinical factors, vascular MRI markers, and CI mechanisms require evaluation for their impact on HL.

Purpose of the Study:

• To assess the influence of clinical factors, vascular MRI markers, and CI mechanisms on hearing loss.
• To investigate the associations between different types of cognitive impairment and hearing loss.

Main Methods:

• 112 patients with CI underwent MRI, amyloid PET, hearing evaluations, and neuropsychological tests.
• Patients were classified into pure-ADCI, pure-LBCI, mixed-ADCI/LBCI, and non-ADCI/LBCI groups based on clinical and PET data.

Main Results:

• Pure-LBCI patients had a higher risk of peripheral HL compared to pure-ADCI and mixed-ADCI/LBCI groups.
• Severe vascular MRI markers in the non-ADCI/LBCI group correlated with increased peripheral HL risk.
• Pure-LBCI patients showed higher comprehension dysfunction risk, even with better cognitive scores, linked to poorer hearing thresholds.

Conclusions:

• Peripheral HL may indicate the absence of significant beta-amyloid deposition in CI patients.
• Peripheral HL is characteristic of pure-LBCI and non-ADCI/LBCI groups, suggesting distinct underlying pathologies.