Auditory Agnosia and Alzheimer's Disease: a Cohort Study

Foundation: recent evidence suggests that disorders caused by the onset of Alzheimer's disease can cause sound agnosia. Objective: to investigate whether patients with mild cognitive impairment and dementia as a symptom of Alzheimer's recognize environmental sounds worse than cognitively healthy people. Method: an experimental and correlational study was carried out with 51 patients, diagnosed with dementia or mild cognitive impairment associated with Alzheimer's, in the period between 2021 and 2022, in a Cognitive Disorders Center of a Public Hospital. Quantitative variables were defined for the demographic data of the sample. Two cohorts, 51 patients and 27 control subjects, were neuropsychologically examined, with recording of their peripheral hearing and a test of twenty everyday sounds. A statistical analysis of the maximum and minimum values, variance and standard deviation was carried out. The Chi-square test was applied for the levels of significance between the variables. The Audacity Team 2018 software was used to process and normalize the audio tracks. The results were presented in quantities. Results: it was shown that Alzheimer's patients presented a relevant impairment when recognizing significant environmental sounds. Patients with mild cognitive impairment and dementia were equally affected, which may serve as an indication that hearing impairment is already present in the early stages of Alzheimer's, there was also evidence of recognition of a specific modality. A reduced ability to correctly recognize and classify everyday sounds impedes participation and can lead to reduced orientation. Conclusions: patients with mild cognitive impairment and dementia associated with Alzheimer's often present agnosia to sounds and this suggests that environmental noise testing is an appropriate screening method for the early stages of the disease.