Impact of odor exposure time on olfactory parameters

Clinical Research ENT Updates 2015;5(2):76–81 doi:10.2399/jmu.2015002006 Impact of odor exposure time on olfactory parameters Emre Günbey, R›fat Karl›, Recep Ünal Department of Otorhinolaryngology, Faculty of Medicine, Ondokuz May›s University, Samsun, Turkey Abstract Özet: Koku maruziyet süresinin koku parametreleri üzerine etkisi Objective: The aim of this study was to assess the impact of odor exposure time on odor threshold, odor identification and discrimination. Amaç: Çal›flmam›z›n amac› koku maruziyet süresinin koku efli¤i, koku alma ve ay›rt etme üzerine etkisinin de¤erlendirilmesi idi. Methods: Ninety healthy volunteers were randomly divided into three groups: Group 1 underwent an olfactory test with the standard odor exposure time (3–4 sec), Group 2 had an odor exposure time of 8–10 seconds, and Group 3 had 30 seconds. Odor parameters of three groups were compared. Yöntem: Doksan sa¤l›kl› eriflkin randomize olarak 3 gruba ayr›ld›. Grup 1’e standart koku maruziyet süresi (3–4 sn), Grup 2’ye 8–10 saniye ve Grup 3’e ise 30 saniye koku maruziyet süresi koku testi uyguland›. Her üç gruba ait koku parametreleri karfl›laflt›r›ld›. Results: Groups 2 and 3 had significantly better odor identification scores than Group 1. There were no statistically significant differences between the three groups in terms of mean odor threshold and discrimination scores. Males of Group 3 had significantly better odor identification scores than males of Groups 1 and 2 and females of Groups 2 and 3 had significantly better odor identification scores than females of Group 1. Conclusion: The results of the present study showed that longer odor stimulation led to higher odor identification scores. However, odor threshold and odor discrimination were independent from the odor exposure time. The odor exposure time of olfactory screening tests may be revised according to the gender in accordance with our findings. Bulgular: Grup 2 ve 3, Grup 1’e göre anlaml› oranda daha iyi koku tan›ma skorlar›na sahipti. Üç grup aras›nda koku efli¤i ve koku ay›rt etme skorlar› aç›s›ndan anlaml› fark yoktu. Grup 3’teki erkekler Grup 1 ve 2’dekilere göre, Grup 2 ve 3’teki kad›nlar ise Grup 1’dekilere göre anlaml› oranda daha iyi koku tan›ma skorlar›na sahip idi. Sonuç: Mevcut çal›flman›n sonuçlar› uzun koku uyar›s›n›n yüksek koku tan›ma skorlar›na yol açt›¤›n› gösterdi. Bununla birlikte, koku efli¤i ve koku ay›rt etme koku maruziyet süresinden ba¤›ms›z idi. Koku tarama testlerindeki koku maruziyet süreleri bizim bulgular›m›zla uyumlu olarak cinsiyete göre revize edilebilir. Keywords: Odor exposure time, odor identification, odor threshold, odor discrimination, Sniffin’ sticks. Anahtar sözcükler: Koku maruziyet süresi, koku tan›ma, koku efli¤i, koku ay›rt etme, Sniffin’ sticks. Olfactory testing offers valuable information in the daily practice of otolaryngologic and neurologic examinations.[1] Several olfactory tests are used for simple, fast, and reliable evaluation of olfactory function, including the University of Pennsylvania Smell Identification Test, the “Sniffin’ sticks” test, European Test of Olfactory Capabilities and the test of the Connecticut Clinical Chemosensory Research Center.[2–4] Sniffin’ sticks is a modern test of nasal chemosensory performance, developed by Kobal and Hummel, consisting of tests of odor threshold, identification, and discrimination.[5,6] ed studies.[1,4,5] This proposal is based on basic information about the physiology of olfaction, odor adaptation, and the processing time of the peripheral and central olfactory pathways.[5] However, recent studies demonstrated that normal olfactory function requires not only the basic sense of smell but also normal cognitive functions, odor memory, and synaptic plasticity.[7,8] Although there are studies about the influences of presentation of odors, distractors, odor concentrations and repeated exposures on olfactory function, there are no accurate data on the objective clinical results or on how olfactory parameters are affected by odor exposure time.[4–8] The recommended and implemented odor exposure time on the Sniffin’ sticks test is 3–4 seconds, in the validat- Correspondence: Emre Günbey, MD. Department of Otorhinolaryngology, Faculty of Medicine, Ondokuz May›s University, 55139, Samsun, Turkey. e-mail: Received: July 2, 2015; Accepted: July 30, 2015 ©2015 Continuous Education and Scientific Research Association (CESRA) Online available at: www.entupdates.org doi:10.2399/jmu.2015002006 QR code: Impact of odor exposure time on olfactory parameters The aim of this study was to assess the impact of odor exposure time on olfactory parameters on the smell screening tests. Materials and Methods Study design This prospective clinical trial was performed at the Department of Otorhinolaryngology at the Faculty of Medicine of Ondokuz May›s University, with the permission of Clinical Trials Ethics Committee (B.30.2.ODM. 0.20.08/1225). Informed consent was obtained from all participants before the study began, and all investigations were conducted in accordance with the Declaration of Helsinki on biomedical studies involving human subjects. Ninety healthy volunteers from the ages of 18 to 60 years underwent an otolaryngologic examination and an olfactory test. The 90 subjects were randomly divided into three groups: Group 1 underwent an olfactory test with the standard odor exposure time (3–4 sec), Group 2 had an odor exposure time of 8–10 seconds, and Group 3 had 30 seconds. Subjects with obstructive nasal pathologies (e.g., severe nasal septum deviation, nasal polyposis) causing conductivetype olfactory dysfunction, severe systemic disease (e.g., uncontrolled diabetes, hypertension, malignancy), neurologic or psychiatric disorders, a history of drug use (e.g., antithyroid drugs, steroids, antidepressants), upper respiratory infections within the past four weeks, or a current history of smoking were excluded from the study. Olfactory testing Sniffin’ sticks (Burghart GmbH, Wedel, Germany) test was applied beside routine otolaryngologic examinations by the blinded researchers.[9] The odor threshold test was performed with n-butanol and was evaluated using a singlestaircase, triple-forced choice procedure.[9,10] The use of 12 common odors determined odor identification, and discrimination. Odorants were presented using commercially available felt-tip pens. During odor presentation, the tip of the pen was placed 15 mm to 25 mm in front of the participant’s nostrils and the pen’s cap was removed by the experimenter for 3–4 seconds for Group 1, 8–10 seconds for Group 2 and 30 seconds for Group 3. Using a multiple forced-choice paradigm, the subjects identified individual odors from a list of four verbal descriptors each, with an interval of at least 30 seconds, to prevent olfactory desensitization.[10] The test result was the sum score of the correctly identified odors. The maximum score for each subtest is 12, resulting in a maximum (...truncated)