Association of Central Auditory Processing Dysfunction With Preclinical Alzheimer's Disease

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Gerontology

Background:

• Preclinical Alzheimer's disease (AD) is characterized by cerebral beta-amyloid (Aβ) deposition in cognitively normal (CN) older adults.
• Early detection of preclinical AD is crucial for timely intervention and management.
• Central auditory processing dysfunction may be an early indicator of neurological changes.

Purpose of the Study:

• To investigate central auditory processing dysfunction using the dichotic digit test-1 digit (DDT1) in CN older adults with cerebral Aβ deposition.
• To explore the potential of the DDT1 as a screening tool for preclinical AD.

Main Methods:

• A cross-sectional, prospective observational cohort study was conducted.
• Participants included CN older adults with a global clinical dementia rating score of 0.
• A comprehensive hearing test battery, including DDT1, was administered.

Main Results:

• Fifty CN older adults were included (38 Aβ-negative, 12 Aβ-positive).
• DDT1 scores were significantly lower in the Aβ-positive group compared to the Aβ-negative group.
• DDT1 better ear score predicted Aβ positivity with high diagnostic accuracy, independent of APOE4 status.

Conclusions:

• Cerebral Aβ deposition may impact central auditory pathways before cognitive decline is apparent.
• The DDT1 demonstrates potential as a screening tool for preclinical Alzheimer's disease in older adults.
• The DDT1 is easily applicable to the elderly population for early AD detection.