Determination of Retronasal Olfactory Threshold Values.

The aim of this study was to generate normative data of retronasal olfactory threshold values for normosmic and hyposmic individuals and to test the validity of that data by determining the discriminative power for normosmic/hyposmic differentiation. Prospective, descriptive and methodological study. The orthonasal olfactory function of 20 normosmic and 20 hyposmic cases was evaluated using the Sniffin' Sticks Olfactory test. Sniffin' Sticks odor threshold, odor discrimination, and odor identification values and threshold discrimination identification (TDI) scores were recorded. A 13-item test battery previously prepared in our Rhinology Laboratory for retronasal olfactory threshold test that consisted of concentrated solutions prepared from 2:1 diluted 99% phenylethyl alcohol (PEA) and water was used. Each concentration was evaluated with water control, and if not answered correctly, the same process was continued by moving to a higher concentration series. Four consecutive correct answers were determined as the patient's retronasal olfactory threshold. A strong correlation was found between Sniffin' Sticks TDI scores and retronasal odor threshold values in the normosmic group (P < .001, r:0.67). A very strong correlation was found between Sniffin' Sticks TDI scores and retronasal olfactory threshold values in the hyposmic group (P < .001, r:0.81). Furthermore, receiver operating characteristic (ROC) analysis revealed that the sensitivity and the specificity of normosmic/hyposmic differentiation of retronasal olfactory threshold test was 95% and 100%, respectively. The diagnostic cutoff value was 8.5. This study shows that the retronasal olfactory test, a psychophysical odor test performed using an orally presented stimulus, can be used to differentiate normosmic and hyposmic cases. 3 Laryngoscope, 131:1608-1614, 2021.

Özay H ，Çetin AÇ ，Ecevit MC 《-》

Validation study of a novel approach for assessment of retronasal olfactory function with combination of odor thresholds and identification.

The present study aimed to establish a test battery for the clinical assessment of retronasal odor thresholds and retronasal odor identification. Prospective case-control series. Sixty participants (36 women, 24 men, mean age 37.6 ± 19.4 years) were enrolled in this study; 36 were healthy controls and 24 were patients with olfactory dysfunction. Orthonasal olfactory function was assessed with the "Sniffin' Sticks" test battery. Retronasal olfaction was assessed with oral odorant delivery using special containers for threshold function, and with oral tasteless powders for odor identification. Retronasal and orthonasal olfaction were significantly correlated for threshold scores, identification score, and the sum of threshold and identification score (TI score). Validity analyses showed that the retronasal TI score was able to discriminate between healthy controls and patients with olfactory dysfunction. Normosmic participants can be distinctly differentiated from patients with olfactory dysfunction using a valid test battery comprised of retronasal threshold and identification tests. Based on the current findings, we advocate a TI score of 16 as a cut-off between patients and controls. Therefore, TI scores of 17 and above would indicate retronasal normosmia.

Yoshino A ，Pellegrino R ，Luckett CR ，Hummel T ... -  《-》

A New Method for Assessment of Retronasal Olfactory Function.

The aim of the study was to develop a test for the assessment of retronasal olfaction in healthy participants and patients with olfactory disorders using "tasteless" powders. Prospective case-control series. A total of 150 participants (110 women, 40 men, mean age = 40 ± 16 years) were recruited for this study; 100 were healthy controls and 50 were patients with olfactory loss due to infections of the upper respiratory tract (n = 25), idiopathic causes (n = 12), sinonasal disease (n = 7), and head trauma (n = 6). Orthonasal olfactory function was evaluated using the Sniffin' Sticks test battery, and retronasal olfaction was evaluated using powders lacking distinctive tastes administered to the oral cavity. To establish test-retest reliability, healthy participants had their orthonasal and retronasal function tested twice. The validity analyses revealed that the selected 16 stimuli differentiated between normosmic participants and patients with olfactory loss, and that retronasal and orthonasal olfaction were highly correlated. The results of the present study indicate that patients with olfactory loss and controls can be clearly separated using a reliable test of retronasal olfaction based on 16 retronasal stimuli. 2b Laryngoscope, 131:E324-E330, 2021.

Yoshino A ，Goektas G ，Mahmut MK ，Zhu Y ，Goektas O ，Komachi T ，Okubo K ，Hummel T ... -  《-》

Validation study of the "Sniffin' Sticks" olfactory test in a British population: a preliminary communication.

The 'Sniffin' Sticks' olfactory test contains pen-like odour dispensing devices which are used to assess olfactory threshold, discrimination and identification. Odour identification is strongly dependent on familiarity with the odours and has an important cultural component which has limited the usefulness of other validated tests. The 'Sniffin' Sticks' test was developed in Germany and is validated in other countries but not in the UK. This study aims to validate the applicability of 'Sniffin' Sticks' in a local population. Prospective controlled study. Rhinology or olfactory disorder clinic. About 82 subjects, 33 healthy volunteers with a reported normal sense of smell, and 49 patients with an impaired sense of smell presenting either at a rhinology or an olfactory disorder clinic. Each subject's olfactory function was assessed using the 'Sniffin' Sticks' test with a maximum score of 48. Threshold, discrimination and identification scores along with the combined olfactory score. The mean age of the subjects tested was 46.7 years; 46 female and 36 male. In the patient group 36 were hyposmic and 13 anosmic. In the healthy volunteers group all subjects were normosmic. In the control group the mean combined olfactory score was 34.5 (±2.5). The mean combined score in the patients group was 20.8 (±7.4). Odour threshold scores were 3.7(±2.8) for patients (hyposmics and anomics) and 8.3(±1.8) for controls. In the identification test the controls mean score was 13.6 (±1.2) for while the patients' mean score was 8.6 (±3.5). In our sample of the local population the combined olfactory and odour identification scores for healthy volunteers and patients with olfactory disorders are comparable with the normative data published on large samples of European populations. However, modification of a few of the distracters is recommended for British patients based on our findings.

Neumann C ，Tsioulos K ，Merkonidis C ，Salam M ，Clark A ，Philpott C ... -  《-》

Evaluation of the efficacy of the 'nasal airflow-inducing manoeuvre' for smell rehabilitation in laryngectomees by means of the Sniffin' Sticks test.

To determine the efficacy of the nasal airflow-inducing manoeuvre (NAIM) as a method for olfactory rehabilitation in laryngectomees by the means of the Sniffin' Sticks test. Prospective open interventional trial. Tertiary academic hospital. Thirty-seven patients after laryngectomy have been screened and 25 patients have been included into the study. The participant's sense of smell was tested with the Sniffin' Sticks test before and after learning the nasal airflow inducing manoeuvre. The individual level of threshold, discrimination and identification (TDI) was determined and the individual threshold, discrimination and identification score was used to classify the patients as being anosmic, hyposmic or normosmic. The primary endpoint was the change of the threshold, discrimination and identification score before and after learning the nasal airflow inducing manoeuvre. The secondary endpoint was a change in the diagnostic group (normosmic, hyposmic and anosmic) after learning of the nasal airflow inducing manoeuvre. There was a statistically significant increase in the total threshold, discrimination and identification score (P < 0.001) and the three sub-scores (P ≤ 0.02) before and after the learning of the nasal airflow inducing manoeuvre. Patients gained seven points on average in the threshold, discrimination and identification score. Twenty of 25 patients showed an increase of five or more point in the threshold, discrimination and identification score. In the classification of the smell ability, 15 of 25 patients showed a change to a higher class (hyposmic to normosmic or from anosmic to hyposmic or normosmic). The nasal airflow inducing manoeuvre is a method for the successful rehabilitation of the sense of smell in laryngectomees. The evaluation with the Sniffin' Sticks tests showed a clinically relevant increase of olfaction in 80% of patients. The teaching of the nasal airflow inducing manoeuvre should be included in post-laryngectomy rehabilitation programmes.

Haxel BR ，Fuchs C ，Fruth K ，Mann WJ ，Lippert BM ... -  《-》