Olfactory dysfunction in mild cognitive impairment and early stage ofalzheimer disease.

Abstract

Background: There is a rapidly increasing prevalence of dementia which requires simple and reliable tests to help diagnose the disease especially at an earlier stage. In our study, we aimed to evaluate the predictive value of testing olfactory functions for diagnosing the mild cognitive impairment (MCI) and the early stage of Alzheimer Disease (AD) and to explore the correlations of olfactory functions with neuropsychological battery. Materials and methods: In current study the participants were separated in three distinct groups. The control group consisted of 19 healthy volunteering participants, the MCI group included 18 subjects and the AD group consisted of 11 selected subjects. Sniffin Sticks Test Battery (SSTB) was performed to assess the olfactory functions. For cognitive evaluation, Mini Mental State Examination (MMSE), Clock Drawing test (CDT), three words three shapes (TWTS), enhanced cued recall test (ECRT) and Geriatric Depression Scale (GDS) was performed. Results: The scores for identifying and differentiating olfaction were significantly varied across the groups. Subjects in the MCI group performed better than the early AD group and healthy group performed better than the MCI group. Olfactory dysfunction also correlated with the cognitive decline which has been revealed in neuropsychological tests in the early AD group. Conclusion: We concluded that the Sniffin Sticks test has significant diagnostic and screening feature for MCI and early AD.