Specific olfactory deficit patterns observed in seniors and associated with cognitive decline

Area of Science:

• Neuroscience
• Gerontology
• Olfactory research

Background:

• Olfactory dysfunction is a common symptom in neurodegenerative disorders.
• It is considered a potential early predictor of cognitive decline.

Purpose of the Study:

• To determine if olfactory dysfunction in the elderly involves a general loss of smell or difficulty identifying specific odors.
• To investigate the correlation between odor misidentification and cognitive scores.

Main Methods:

• Recruited seniors from the Quebec Nutrition and Successful Aging (NuAge) cohort for the Olfactory Response and Cognition in Aging (ORCA) sub-study.
• Utilized the University of Pennsylvania smell identification test (UPSIT) for olfactory function assessment.
• Employed the telephone Mini Mental State Examination (t-MMSE) and the French version of the Telephone Interview for Cognitive Status Modified (F-TICS-m) for cognitive status evaluation.

Main Results:

• Seniors demonstrated specific olfactory loss, with particular difficulty identifying lemon, pizza, fruit punch, cheddar cheese, and lime odors.
• Significant sex-based differences were observed in the ability to detect certain odors.
• Misidentification of specific scents was associated with cognitive scores, with sex-specific patterns emerging upon separate analysis.

Conclusions:

• The relationship between cognitive scores and scent misidentification suggests that impaired smell for specific odors may indicate impending cognitive decline.
• Findings support olfactory function testing in the elderly as a potential diagnostic tool for cognitive impairment.