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Olfactory Assays for Mouse Models of Neurodegenerative Disease
Published on: August 25, 2014
Awareness of olfactory dysfunction in Parkinson's disease
Birgit Leonhardt1, Ramin Tahmasebi2, Reinhold Jagsch1
1Faculty of Psychology, University of Vienna.
Neuropsychology
|April 5, 2019
Summary
Most Parkinson's disease (PD) patients overestimate their sense of smell, indicating poor self-awareness of olfactory impairment. This overestimation, alongside reduced odor identification, may signal cognitive decline in PD.
Area of Science:
- Neuroscience
- Olfactory Research
- Cognitive Science
Background:
- Olfactory impairment is a common symptom in Parkinson's disease (PD).
- Individuals with PD often overestimate their smelling ability, a metacognitive error linked to aging, depression, and cognitive impairment.
- Awareness of olfactory deficits is crucial for understanding PD progression.
Purpose of the Study:
- To investigate olfactory awareness in non-demented Parkinson's disease patients.
- To determine the influence of factors like depression and cognitive function on olfactory self-awareness.
- To assess the reliability of self-reported olfactory function in PD.
Main Methods:
- 124 non-demented PD patients and 154 elderly controls were evaluated.
- The Sniffin' Sticks Odor Identification Test (OIT) assessed objective olfactory function.
- Subjective Olfactory Capability (SOC), depressive symptoms, and cognitive functions (memory, executive function) were measured.
Main Results:
- Moderate correlation between objective (OIT) and subjective (SOC) smell tests in PD patients, versus small in controls.
- 52% of PD patients overrated their sense of smell; 27% were aware of hyposmia.
- PD patients overrating their smell or aware of hyposmia had poorer executive functions than normosmic PD patients.
Conclusions:
- The majority of Parkinson's disease patients overestimate their olfactory abilities, making self-reports unreliable.
- Reduced odor identification and impaired executive functions in PD may share underlying pathology.
- Olfactory deficits and executive dysfunction could serve as biomarkers for cognitive impairment in PD.
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