Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Feb:35:36-41.
doi: 10.1016/j.parkreldis.2016.11.010. Epub 2016 Nov 21.

Sniffing the diagnosis: Olfactory testing in neurodegenerative parkinsonism

F Krismer  1 , B Pinter  1 , C Mueller  1 , P Mahlknecht  1 , M Nocker  1 , E Reiter  1 , A Djamshidian-Tehrani  1 , S M Boesch  1 , G K Wenning  1 , C Scherfler  1 , W Poewe  1 , K Seppi  2
Affiliations

Sniffing the diagnosis: Olfactory testing in neurodegenerative parkinsonism

F Krismer et al. Parkinsonism Relat Disord. 2017 Feb.

Abstract

Objective: To determine the diagnostic utility of olfactory testing in patients with neurodegenerative parkinsonism.

Methods: The Sniffin' Sticks test battery for assessment of odor identification, discrimination, and threshold was applied to patients with Parkinson's disease (PD), multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) as well as healthy controls (HC). Two different cohorts were analyzed: A PD/healthy control that included PD patients and HC as well as a PD/diseased control cohort for which patients PD, MSA and PSP were recruited. The former cohort was exploited to calculate cut-off values that discriminate PD patients from HC with a sensitivity (sensitivity-weighted cut-off) or specificity (specificity-weighted cut-off) exceeding 95%, respectively. The PD/diseased controls cohort was used to determine the diagnostic accuracy using these cut-off values in discriminating patients with neurodegenerative parkinsonism.

Results: PD patients (n = 67) performed significantly worse in olfactory testing than HC (n = 41) and patients with MSA (n = 23) or PSP (n = 23). There was no significant difference in olfactory function between MSA and PSP patients. Diagnostic performance of the identification subscore was similar to the sum score of the Sniffin' Sticks test (AUC identification test 0.94, AUC sum score 0.96), while threshold and discrimination subscores were inferior. In patients with parkinsonism, the specificity-weighted cut-off predicted a diagnosis of PD with a sensitivity and specificity of 76.6 and 87.0%, respectively. The discriminative value of this cut-off in separating PD from MSA was 76.7% (sensitivity) and 95.7% (specificity). The corresponding, prevalence-adjusted positive predictive value of olfactory testing exceeded 95%.

Conclusions: Our data suggest that assessment of olfactory function, particularly odor identification, can be useful to discriminate PD from atypical parkinsonian disorders, particularly MSA patients.

Keywords: Multiple system atrophy; Olfaction; Parkinson's disease; Progressive supranuclear palsy; Sniffin' sticks.

PubMed Disclaimer

Publication types

LinkOut - more resources