title: Olfactory evaluation in Mild Cognitive Impairment: correlation with neurocognitive performance and endothelial function.
abstract: Mild Cognitive Impairment (MCI) is an intermediate condition between normal aging and dementia, associated with an increased risk of progression into the latter within months or years. Olfactory impairment, a well-known biomarker for neurodegeneration, might be present in the condition early, possibly representing a signal for future pathological onset. Our study aimed at evaluating olfactory function in MCI and healthy controls in relation to neurocognitive performance and endothelial function. A total of 85 individuals with MCI and 41 healthy controls, matched for age and gender, were recruited. Olfactory function was assessed by Sniffin' Sticks Extended Test (Burghart, Medizintechnik, GmbH, Wedel, Germany). A comprehensive neurocognitive assessment was performed. Endothelial function was assessed by flow-mediated dilation (FMD) of the brachial artery by ultrasound. MCI individuals showed an impaired olfactory function compared to controls. The overall olfactory score is able to predict MCI with a good sensitivity and specificity (70.3 and 77.4% respectively). In MCI, olfactory identification score is correlated with a number of neurocognitive abilities, including overall cognitive status, dementia rating, immediate and delayed memory, visuospatial ability and verbal fluency. FMD was reduced in MCI (2.90 ± 2.15 vs. 3.66 ± 1.96%, P = 0.016) and was positively associated with olfactory identification score (ρs=0.219, P = 0.025). The association remained significant after controlling for age, gender, and smoking. In conclusion, olfactory evaluation is able to discriminate between MCI and healthy individuals. Systemic vascular dysfunction might be involved, at least indirectly, in olfactory dysfunction in MCI.
authors.affiliation: Clinical Physiology Institute - National Research Council (IFC-CNR), Via Moruzzi 1, 56124, Pisa, Italy.
authors.forename: Alessandro
authors.identifier: 0000-0001-8335-5541
authors.initials: A
authors.lastname: Tonacci
authors.affiliation: Clinical Physiology Institute - National Research Council (IFC-CNR), Via Moruzzi 1, 56124, Pisa, Italy.|Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Bruno
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Ghiadoni
authors.affiliation: Clinical Physiology Institute - National Research Council (IFC-CNR), Via Moruzzi 1, 56124, Pisa, Italy.
authors.forename: Lorenza
authors.initials: L
authors.lastname: Pratali
authors.affiliation: Neuroscience Institute, National Research Council (IN-CNR), Pisa, Italy.|Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Berardi
authors.affiliation: Neurological Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Gloria
authors.initials: G
authors.lastname: Tognoni
authors.affiliation: Neurological Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Cintoli
authors.affiliation: Neurological Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Leda
authors.initials: L
authors.lastname: Volpi
authors.affiliation: Neurological Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Ubaldo
authors.initials: U
authors.lastname: Bonuccelli
authors.affiliation: Clinical Physiology Institute - National Research Council (IFC-CNR), Via Moruzzi 1, 56124, Pisa, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Sicari
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Taddei
authors.affiliation: Neuroscience Institute, National Research Council (IN-CNR), Pisa, Italy.|Laboratory of Neurobiology, Scuola Normale Superiore, Pisa, Italy.
authors.forename: Lamberto
authors.initials: L
authors.lastname: Maffei
authors.affiliation: Clinical Physiology Institute - National Research Council (IFC-CNR), Via Moruzzi 1, 56124, Pisa, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Picano
mesh_terms: D000368:Aged; D001916:Brachial Artery / Q000502:physiology; D016022:Case-Control Studies; D003071:Cognition; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D009831:Olfactory Mucosa / Q000098:blood supply / Q000502:physiology*; D055696:Olfactory Perception; D012903:Smell
keywords: Mild Cognitive Impairment; cognition; olfaction disorders; smell