Threshold and suprathreshold component analysis in olfactory dysfunction: a retrospective study.

Area of Science:

• Otolaryngology
• Neuroscience
• Sensory Science

Background:

• Olfactory dysfunction significantly impacts quality of life.
• Understanding variations in olfactory loss is crucial for diagnosis and treatment.
• The Connecticut Chemosensory Clinical Research Centre (CCCRC) test is a standard tool for assessing olfactory function.

Purpose of the Study:

• To analyze variations in olfactory threshold and odour identification using the CCCRC test.
• To investigate these variations across different grades of olfactory dysfunction.
• To examine the impact of various nasal conditions on olfactory loss.

Main Methods:

• Retrospective observational study design.
• Utilized data from the CCCRC olfactory test.
• Analyzed olfactory threshold and odour identification scores.

Main Results:

• Olfactory dysfunction predominantly affected males across all grades.
• Anosmia/severe hyposmia was more prevalent in chronic rhinosinusitis without polyps (87.5%) compared to those with polyps (68%).
• Atrophic rhinitis and post-traumatic loss showed high rates of anosmia (90%), contrasting with allergic rhinitis (30.7%). Pepper was the most affected smell, except in atrophic rhinitis where asafoetida and baby powder were more affected.

Conclusions:

• Odour identification is relatively preserved in most inflammatory sinonasal conditions, even with maximal threshold impairment.
• A preserved suprathreshold odour identification score may indicate a better prognosis in patients with similar CCCRC test scores.
• These findings highlight the importance of assessing both threshold and identification in olfactory dysfunction.