Olfactory Testing With Focus on Odor Identification for Early Detection of Alzheimer's Disease in Mild Cognitive Impairment.

This review examines the application of olfactory testing in the early stages of mild cognitive impairment (MCI) associated with Alzheimer's disease (AD), highlighting its potential and challenges in early screening and intervention. Olfactory function is typically divided into three domains: odor identification, odor discrimination, and odor threshold. Among these, odor identification and discrimination are closely linked to higher cognitive processes and exhibit significant impairment in patients with AD and MCI. Moreover, the anatomical and functional characteristics of the olfactory system make it a promising target for the early detection of neurodegenerative disorders. This review also outlines various olfactory assessment tools and evaluates their clinical utility. Future research should aim to enhance the accuracy and cultural adaptability of olfactory tests and integrate them with multimodal diagnostic approaches to advance early detection and intervention strategies for AD.