Olfactory dysfunction in aging and neurodegenerative diseases

Area of Science:

• Neuroscience
• Biomarkers
• Aging

Background:

• Neurodegenerative diseases, such as Parkinson's disease (PD) and Alzheimer's disease (AD), are often age-related.
• Early identification of neurodegenerative disease risk is crucial for timely intervention.
• Olfactory dysfunction (OD) is frequently observed in the early stages of these conditions.

Purpose of the Study:

• To systematically review human olfactory tests and animal olfaction assessments.
• To explore the relationship between olfactory dysfunction and normal aging, PD, AD, and other conditions.
• To discuss the potential of olfactory dysfunction as a biomarker for neurodegenerative disease diagnosis.

Main Methods:

• Systematic literature review of olfactory testing methods.
• Analysis of olfactory assessments in human patients and animal models.
• Examination of the association between olfactory dysfunction and aging/neurodegenerative diseases.

Main Results:

• Olfactory dysfunction is prevalent in early-stage Parkinson's disease (90%) and Alzheimer's disease (85%).
• Olfactory function decline is linked to normal aging and various neurodegenerative conditions.
• A range of olfactory tests are available for human and animal studies.

Conclusions:

• Olfactory dysfunction serves as a promising early biomarker for neurodegenerative diseases.
• Further research into olfactory assessments can enhance early diagnosis and risk identification.
• Understanding OD's role is vital for developing strategies to postpone or prevent neurodegeneration.