Executive dysfunction and presbycusis in older persons with and without memory loss and dementia.

OBJECTIVE: To determine the relation of age-related auditory processing dysfunction and executive functioning.

BACKGROUND: Central auditory dysfunction is common in Alzheimer dementia, but the mechanism is not established.

METHOD: A total of 313 volunteers from the Adult Changes in Thought surveillance cohort with adequate peripheral hearing were included in the study. Outcome measures such as (1) peripheral audition; (2) auditory-evoked potentials; (3) central auditory tests (Synthetic Sentence Identification with Ipsilateral Competing Message, Dichotic Sentence Identification, Dichotic Digits); (4) Executive Functioning: Trail Making; Clock Drawing, Stroop Color and Word, and subtests from the Cognitive Abilities Screening Instrument were used to measuring the mental concentration. A composite executive functioning score was created using item response theory.

RESULTS: The composite executive functioning score was significantly associated with each central auditory measure, explaining 8% to 21% of the variance. Trails B test was most strongly associated with the auditory outcomes, explaining 8% to 14% of the variance. The relation between executive functioning and central auditory function was still significant when participants diagnosed with memory impairment or dementia were excluded.

CONCLUSIONS: In elderly persons, reduced executive functioning is associated with central auditory processing, but not with primary auditory function. This suggests that central presbycusis and executive dysfunction may result from similar neurodegenerative processes.