Smell and preclinical Alzheimer disease: study of 29 patients with amnesic mild cognitive impairment.

Odour discrimination and identification performance correlated more prominently than detection thresholds with performance on neuropsychological tests. We concluded that the olfactory deficit occurs early in aMCI, so we suggest introducing the clinical routine use of the olfactory test for early identification of the progression of the decline from aMCI to AD.