Evaluation of olfactory dysfunction in neurodegenerative diseases

Area of Science:

• Neurology
• Neuroscience
• Sensory Science

Background:

• Olfactory dysfunction is linked to several neurological diseases, including Parkinson's, Alzheimer's, multiple sclerosis, Huntington's disease, and motor neuron disease.
• Changes in odor identification, discrimination, and threshold can be early indicators of these pathologies.
• These early signs are often undiagnosed, delaying timely intervention.

Purpose of the Study:

• To review major neurological diseases associated with olfactory dysfunction.
• To discuss instrumental approaches for evaluating olfactory function.
• To highlight the potential of new methods for early diagnosis.

Main Methods:

• Review of literature on neurological diseases and olfactory dysfunction.
• Discussion of psychophysical testing for olfactory assessment.
• Exploration of olfactory event-related potentials (OERPs) and functional magnetic resonance imaging (fMRI) with olfactometer-supported stimuli delivery.

Main Results:

• Olfactory dysfunction is a common feature across various neurodegenerative disorders.
• Psychophysical tests, OERPs, and fMRI are key methods for assessing olfactory function.
• OERPs and fMRI demonstrate potential as supplementary diagnostic tools.

Conclusions:

• Olfactory dysfunction serves as a significant early marker for neurological diseases.
• Advanced instrumental approaches, particularly OERPs and fMRI, offer promising avenues for early detection.
• Integrating these methods into clinical protocols could improve the diagnosis of neurological conditions.