Smell and preclinical Alzheimer disease: study of 29 patients with amnesic mild cognitive impairment.
OBJECTIVE
To evaluate the olfactory function in patients with amnesic mild cognitive impairment (aMCI) and the relationship to the progression from aMCI to Alzheimer disease (AD).


METHODS
Cohort prospective study on aMCI patients at the first evaluation (T0) and at the 18-month follow-up (T1).


METHODS
Alzheimer Unit of the University of L'Aquila, Italy.


METHODS
Twenty-nine aMCI patients were enrolled in this study.


METHODS
Olfactory function was studied with the Sniffin' Sticks Screening Test (SSST) and the Sniffin' Sticks Extended Test (SSET). Olfactory functions were related to neurocognitive functions assessed by the Mini-Mental State Examination (MMSE) and the Mental Deterioration Battery (MDB).


RESULTS
At T0, aMCI patients showed an olfactory impairment and all of the aMCI patients had lower olfaction scores at T1. At T1, 9 of the 29 aMCI patients (31%) developed AD and had lower mean SSST and SSET scores than 20 aMCI patients who did not develop AD. The most significant relationship was found between olfactory discrimination and visuospatial ability, language skill, and the Rey Immediate test of the MDB and between olfactory identification and the Rey Delayed test.


CONCLUSIONS
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.
Fusetti
Marco
M
Fioretti
Alessandra B
AB
Silvagni
Fabrizio
F
Simaskou
Maria
M
Sucapane
Patrizia
P
Necozione
Stefano
S
Eibenstein
Alberto
A
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology*; D003072:Cognition Disorders / Q000503:physiopathology*; D004192:Discrimination, Psychological; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D000857:Olfaction Disorders / Q000503:physiopathology*; D011446:Prospective Studies; D012372:ROC Curve