Clinical Feasibility of Scent Survey for Screening Test for Olfactory Function

BACKGROUND AND OBJECTIVES: The scent survey for screening (SSS) test is a subjective olfactory questionnaire devised for this study. We demonstrated the correlation of the SSS test with other olfactory tests and the efficacy of the SSS test as an olfactory screening test compared to KVSSII. SUBJECTS AND METHOD: A total of 363 patients who visited our ORL outpatient department underwent the SSS test, VAS, and KVSS I and II. The patients were divided into two groups, a group with normal olfactory function and a group with olfactory dysfunction according to the KVSS II test. In each group, the correlations between the olfactory tests were studied, and the cut-off value of the SSS test as a screening test was investigated. RESULTS: There was positive correlation between CCSIT and KVSS I, II, T, D, and I tests and the SSS test in the total group and in the olfactory dysfunction group (p<0.05). The identification test in the KVSS II showed the highest positive correlation. While the cut-off value of normal olfactory function in the KVSS II is 28, the SSS test showed the highest specificity and sensitivity of 74 under an ROC curve. CONCLUSION: The SSS test showed very high correlation with other olfactory tests, especially in an olfactory dysfunction group. This result indicates that the SSS is appropriate as a screening test to select people with olfactory disorder.

The Effect of Sleep Disordered Breathing on Olfactory Functions: Analysis by Apnea-Hypopnea Index

OBJECTIVES: One hypothesis of obstructive sleep apnea syndrome (OSAS) is that long-standing snoring vibrations and hypoxia of the nerves cause a local neuropathy in the upper airway during sleep. The aim of this study was to investigate olfactory function in subjects comprising snorers and untreated subjects with OSAS, and to correlate data with polysomnographic parameters. METHODS: Sixty-nine patients were evaluated for snoring from January 2010 to December 2013. The mild group (apneahypopnea index [AHI]<15) consisted of 19 subjects, and the moderate-severe group (AHI≥15) consisted of 50 subjects. Exclusion criteria were conductive olfactory dysfunction, previous tonsil or soft palatal surgery, central sleep apnea, and medications that are known to affect peripheral nerves. Nocturnal polysomnography and olfactory function test such as Korean version of Sniffin’s stick test I, II (KVSS I, II) were performed. RESULTS: There was a significant difference in body mass index, average oxygen saturation (SaO2), lowest SaO2, average snoring duration, and KVSS I, II between the two groups. AHI was related to odor threshold score, and average SaO2 was related to odor discrimination score. But, odor identification score showed no relation with AHI and average SaO2 except for age. Average SaO2 and AHI were closely related to the function of smell. CONCLUSION: Hypoxia and low nasal airflow caused by OSAS may have an effect on the olfactory function. On comparison between the two groups, patients with a high AHI, especially those with OSAS, had an olfactory dysfunction. Also, low average oxygen is the main risk factor in determining the olfactory function. In people with OSAS, the possibility of olfactory dysfunction should be considered and an olfactory function test should be performed.

Assessment of Change in Palatal Sensation in Obstructive Sleep Apnea Patients by Using Two-Point Palatal Discrimination

OBJECTIVES: Patients with obstructive sleep apnea syndrome (OSAS) have impaired responses to inspiratory resistive loading during sleep. This may be due, in part, to a change in the upper airway sensation. Therefore, we hypothesized that patients with OSAS have diminished upper airway sensation due to snoring. METHODS: A total of 53 participants were selected based on clinical evaluation and polysomnography. Two-point discrimination was measured with modified calipers in the tongue and soft palate. RESULTS: A total of 10 participants were included in the control group, 12 participants in the simple snoring group, and 27 participants in the OSAS group. There were 12 patients in the impaired sensation group of the OSAS group. On comparing polysomnography, patients with impairment of their palatal sensory input in two-point discrimination (TPD) had a more protracted duration of the longest snoring episode than those with simple snoring and normal sensation. Patients with decreased sensory input in TPD had longer average duration of snoring episodes and relative snoring time than those with simple snoring and normal sensory input in cold uvular TPD. Comparison of the cold uvular TPD for normal sensation and impaired sensation in patients with OSAS after treatment showed a different trend. CONCLUSION: Impaired sensation of the soft palate was correlated with the longest snoring episode duration, average snoring episode duration, and relative snoring time. It is helpful in detecting the early stage of neural degradation in OSAS patients by assessing snoring components of polysomnography and TPD in the soft palate.