Identifying normosmics: a comparison of two populations

Area of Science:

• Olfactory neuroscience
• Sensory perception research
• Clinical chemosensory science

Background:

• Olfactory dysfunction diagnosis relies on accurate olfactory function tests.
• The Connecticut Chemosensory Clinical Research Center (CCCRC) developed a standardized olfactory test.
• Establishing norms for olfactory tests is crucial for diagnosing smell disorders.

Purpose of the Study:

• To evaluate the CCCRC olfactory function test's ability to identify normosmic (normal) individuals.
• To analyze the distribution of olfactory function categories within a cohort of normal subjects.
• To assess the test-retest reliability and normal day-to-day variability of the butanol threshold subtest.

Main Methods:

• Administration of the CCCRC olfactory function test to 65 healthy subjects.
• Categorization of subjects into five olfactory function levels: normosmic, mild, moderate, severe hyposmia, and anosmia.
• Further investigation of the butanol threshold subtest for reliability and variability.

Main Results:

• A higher percentage of subjects were categorized as hyposmic compared to CCCRC distributions, primarily due to elevated butanol thresholds.
• The butanol threshold subtest demonstrated variability, necessitating further study for test-retest reliability and daily fluctuations.
• Score distributions highlighted potential differences in olfactory perception within the normosmic range.

Conclusions:

• The CCCRC olfactory test provides a framework for classifying olfactory function.
• Elevated butanol thresholds in some subjects suggest a need for refined norms and understanding of hyposmia.
• Further research on the butanol threshold subtest is essential for accurate olfactory disorder diagnosis and treatment.