Mild cognitive impairment (MCI) is a transient
status between physiologic ageing and dementia. Each year
more than 12% of subjects with MCI develop Alzheimer’s
disease. This study evaluated the presence of an olfactory
deficit in amnesic MCI (aMCI) patients. Twenty–nine
patients diagnosed with aMCI and a homogeneous control
group of 29 subjects were enrolled in the study. Olfactory
function was assessed by the Sniffin’ Sticks Screening Test
(SSST) and the Mini Mental State Examination, the Clinical
Dementia Rating, the Geriatric Depression Scale and the
Mental Deterioration Battery were used to evaluate the neurocognitive
status. aMCI patients showed a significant
impairment of their olfactory identification compared to
controls (SSST score: 8.3±2.1 vs. 10.8±0.9; p<0.001).
These results suggest that olfactory tests should be part of
the diagnostic armamentarium of pre–clinical dementia. A
long–term follow up might confirm the olfactory identification
function as an early and reliable marker in the diagnosis
of pre–clinical dementia.