Objectives: To determine the prevalence and characteristics of hearing loss in patients undergoing examination because of a memory disorder, to determine whether currently used screening tools were adequate for use in this specific population, and to determine if patients with Alzheimer disease reliably report hearing problems.
Design: Case-control study.
Patients: A consecutive sample of 52 patients: 30 patients who met the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association criteria for probable Alzheimer disease (group 1) and 22 patients with other forms of cognitive impairment (group 2).
Methods: Patients underwent a hearing screening that included a case history, a visual inspection of the external ear canal and tympanic membrane, and pure tone audiometry. Patients and their caregivers completed a questionnaire intended to assess hearing impairment and perceived disability.
Outcome measures: Pass or fail on pure tone audiometry and pass or fail on a hearing impairment questionnaire.
Results: Of the 52 patients, 49 had significant hearing loss. No difference was found in the failure rate between patients in groups 1 and 2. In group 1, a significant discrepancy was found between the patient's self-report and that of their caregivers, whereas in group 2, the self-report was reliable. The prevalence of hearing loss in this population greatly exceeds the prevalence in healthy aged controls.
Conclusion: The extraordinarily high prevalence of hearing loss in this selected population suggests that a hearing evaluation should be part of any assessment of cognitive function.