Olfactory deficit and hippocampal volume loss for early diagnosis of Alzheimer disease: a pilot study.

Abstract BACKGROUND: The aim of this pilot study was to verify the role of olfactory test and volumetric magnetic resonance imaging measure of hippocampus to predict conversion from mild cognitive impairment to Alzheimer disease (AD). MATERIALS AND METHODS: Eighteen patients with amnesic mild cognitive impairment, broadly defined, were followed at 12 months. Hypothesized baseline predictors for follow-up conversion to AD were olfactory deficit and hippocampal volumes loss. RESULTS: In the 1-year follow-up, 5 patients converted to AD. The 2 clinical predictors olfactory test and hippocampal volume loss showed the same sensitivity of 92.3% but the olfactory test showed a higher specificity than the hippocampal volume loss (75% vs. 60%). CONCLUSIONS: Our findings suggest the potential utility of olfactory test and hippocampal volume loss for early detection of AD.