OBJECTIVESTo establish the normal value of Sniffin' Sticks test in Chinese population and to explore it's clinical application in China.

METHODSOne hundred and five healthy volunteers were choosen from the department of physical examination of Beijing Tongren Hospital between 2007 and 2013. Another 165 patients complained of abnormal olfactory function were obtained from the outpatient clinic of the department of otorhinolaryngology head and neck surgery in the same period and were divided into two groups: 92 in hyposmia and 73 in functional anosmia group. The 270 subjects were divided into 3 subgroups:younger group ( <35 years of age), middle-age group (35-55 years of age) and older group ( > 55 years of age). The olfactory functions were examined with Sniffin' Sticks test and T & T test, respectively. All analyses were performed using SPSS 12.0 software.

RESULTSFor the normal value of Sniffin' Sticks test, TDI score was > 30.12 for younger group, > 27.37 for middle-age group and > 20.43 for older group; the mean TDI score was 32.12 ± 3.95 for healthy group, 17.52 ± 10.37 for hyposmia and 3.56 ± 3.49 for functional anosmia group; the differences in TDI score, olfactory threshold, discrimination threshold and identification threshold between healthy group and olfactory dysfunction group with different ages had statistical significance (Younger group: FTDI = 125.136, P = 0.000; FT = 49.454, P = 0.000;FD = 89.037, P = 0.000; FI = 39.888, P = 0.000; Middle-age group: FTDI = 190.240, P = 0.000; FT = 128.374, P = 0.000;FD = 174.122, P = 0.000;FI = 178.945, P = 0.000;Older group: FTDI = 72.992, P = 0.000; FT = 26.599, P = 0.000; FD = 77.119, P = 0.000; FI = 88.107, P = 0.000, respectively) . The mean T & T value was -1.00 ± 0.98 for healthy group, 2.27 ± 2.01 for hyposmia and 5.89 ± 0.14 for functional anosmia group. T & T score between healthy group and olfactory dysfunction group with different ages had statistical significance (Fyounger = 158.144, P = 0.000; Fmiddle-age = 247.695, P = 0.000; Folder = 70.579, P = 0.000, respectively). TDI score of the Sniffin' Sticks test result was correlated with T & T value (r = -0.927, P < 0.01); T & T threshold was correlated with the olfactory threshold, discrimination threshold and identification threshold of Sniffin' Sticks test (rT = -0.846, P < 0.01, rD = -0.908 P < 0.01, rI = -0.864, P < 0.01, respectively).

CONCLUSIONSSniffin' Sticks test and T & T olfactometry are able to differentiate normosmia from hyposmia and anosmia with high reliability and consistency in test results.Sniffin' Sticks test can assess subject's olfactory function status more thoroughly and is suitable for application in Chinese population.

Humans ; Odorants ; Olfaction Disorders ; diagnosis ; Reproducibility of Results ; Sensory Thresholds ; Smell

BACKGROUND AND OBJECTIVES: The odorant confusion matrix (OCM) odor identification test is a kind of suprathreshold odor identification test using 10 synthetic odorants as stimuli and confusion matrix consisted of closed alternatives. This test is known to have an advantage in qualitative diagnosis of olfactory dysfunction by analyzing mis-identification of odorants at specific nerve dysfunctions. The aim of this study is whether we can use this OCM odor identification test for comparing normals with patients with olfactory disturbance. MATERIALS AND METHODS: The OCM odor identification test using 10 synthetic odorants familiar to Korean was applied to 40 normals and 32 patients who showed decreased sense of smell without sinonasal diseases. Percent-corrects of normals were compared with patients and with olfactory thresholds by a modified ascending method of limits (CCCRC) test using successively diluted 1-butanol. RESULTS: Percent-corrects of normals in the OCM odor identification test was higher than those of patients with statistical significance (p<0.001), and the results of OCM odor identification test was well correlated with those of the CCCRC olfactory threshold test (r=0.77). CONCLUSION: The OCM odor identification test exhibited no problems in discriminating patients from normals and can be used in clinical contexts.
1-Butanol ; Diagnosis ; Humans ; Odors* ; Olfaction Disorders ; Smell

The sense of smell is one of the essential tools for all living things to survive. With recent increase in diseases associated with olfactory dysfunction, the evaluation of olfactory function aims to shed light on the understanding and assessment of the human olfactory system. The methods for assessing the olfactory function are largely divided into electrophysiological and psychophysical methods. The psychophysical inspections such as University of Pennsylvania Smell Identification Test (UPSIT), The Sniffin' Stick, and T & T Olfactometer are methods mostly based on questionnaires or simple apparatus. Those have been generally used in clinical and research field due to their relatively short examination time and low cost. The electrophysiological tests evaluate olfactory function based on objective measurements like biosignals and medical imaging. Compared to the psychophysical methods, they comparably have higher reliability and are possible to assess more specific diagnosis. However, the system configuration seems to be more complicated. In this paper, we review the overall evaluation methods of olfactory functions and suggest complementary points to improve conventional technologies.
Diagnosis ; Diagnostic Imaging ; Humans ; Olfaction Disorders ; Olfactometry ; Pennsylvania ; Smell* ; Surveys and Questionnaires

MRI scanning is an important technique to evaluate the olfactory system, special scanning parameters could reveal the fine structures of the olfactory pathway. Olfactory cleft, olfactory bulb/tract, olfactory sulcus and olfactory center are the main targets of the scanning. Chronic rhino-sinusitis, head trauma, congenital dysplasia and neural degenerative diseases are the primary causes of the olfactory dysfunction and have particular imaging presentations respectively. Besides indicating the olfactory pathway lesions, MRI could also present the etiology and the prognosis of the olfactory disorder.
Humans ; Magnetic Resonance Imaging ; Olfaction Disorders ; diagnosis ; Olfactory Bulb ; Olfactory Pathways

OBJECTIVETo analyze the correlation between olfactory bulb(OB) volume with depth of olfactory sulcus (OS) and olfactory function in patients with idiopathic olfactory loss (IOL).

METHODSForty patients with IOL and forty normal controls were compared in terms of olfactory function T&T testing and magnetic resonance imaging (MRI, observation of OB volume and depth of OS). T&T testing and MRI were performed again after a year in 40 IOL patients, the results were compared with the first time.

RESULTSOB volume of left side in IOL patients was (30.31 ± 4.07) mm(3), right side was (30.82 ± 4.14) mm(3), average OB volume was (30.53 ± 4.10) mm(3); OB volume of left side in normal controls was (49.56 ± 7.19) mm(3), right side was (49.84 ± 7.25) mm(3), average OB volume was (49.73 ± 7.21) mm(3). OB volume was lower in IOL patients as compared to controls (t value were 8.122, 8.274, 8.231, all P < 0.01). OS depth study revealed no statistical different between IOL patients and controls (t value were 0.998, 1.017, 1.001, all P > 0.05). Olfactory discriminate threshold was negatively correlated with OB volume in IOL patients (r = -0.53, P < 0.05). There was no correlation with the depth of OS (r = -0.19, P > 0.05). Among 40 IOL patients, when followed-up, 12 showed increased in OB volume and olfactory function after a year, but no statistical difference was found with the first time (t value were 0.831, 0.864, 0.826, all P > 0.05). The other 28 patients showed no significant changes of OB volume and olfactory function.

CONCLUSIONSThe OB volume was lower in IOL patients as compared to normal controls. The depth of OS showed no significant changes in IOL patients. The OB volume was correlated with olfactory function. The depth of OS did not correlated with the olfactory function. Some IOL patients showed increased OB volume and improved olfactory function with the development of the disease.

Humans ; Magnetic Resonance Imaging ; Olfaction Disorders ; diagnosis ; Olfactory Bulb ; anatomy & histology ; Prefrontal Cortex ; anatomy & histology ; Smell

In addition to acute respiratory symptoms,coronavirus disease 2019(COVID-19)could cause olfactory dysfunction,which becomes the only clinical manifestation of COVID-19 in some cases.We review the epidemiological characteristics,pathological mechanism,screening value,treatment and prognosis of olfactory dysfunction in patients with COVID-19,aiming to achieve an in-depth understanding of the early diagnosis,quarantine,scientific treatment and prognosis of COVID-19.
COVID-19 ; Early Diagnosis ; Humans ; Olfaction Disorders/etiology* ; SARS-CoV-2 ; Smell

Olfactory dysfunction is a relatively common disorder that is often under-recognized by both patients and clinicians. It occurs more frequently in older ages and men, and decreases patients' quality of life, as olfactory dysfunction may affect the emotion and memory functions. Three main causes of olfactory dysfunction are sinonasal diseases, upper respiratory viral infection, and head trauma. Olfactory dysfunction is classified quantitatively (hyposmia and anosmia) and qualitatively (parosmia and phantosmia). From a pathophysiological perspective, olfactory dysfunction is also classified by conductive or sensorineural types. All patients with olfactory dysfunction will need a complete history and physical examination to identify any possible or underlying causes and psychophysical olfactory tests are essential to estimate the residual olfactory function, which is the most important prognostic factor. CT or MRI may be adjunctively used in some indicated cases such as head trauma and neurodegenerative disorders. Functional MRI (fMRI) and psychophysiological tests (olfactory event-related potential, OERP) are also used in the research setting. Compared to rapid progress that has occurred in fields of basic science and diagnostic tools for the therapy of other diseases and disorders, treatments for olfactory loss are still in a state of unmet need. In most olfactory dysfunctions, there has been no well-designed randomized controlled study to justify or prove effective treatment modalities. Therefore, with more attention to the problem and further research we can expect breakthroughs in the treatment of smell loss in the near future.
Craniocerebral Trauma ; Diagnosis* ; Evoked Potentials ; Humans ; Magnetic Resonance Imaging ; Male ; Memory ; Neurodegenerative Diseases ; Olfaction Disorders ; Physical Examination ; Quality of Life ; Smell

OBJECTIVE: To analyze the relationship between olfactory bulb (OB) volume, depth of olfactory sulcus (OS) and olfactory function in patients with Alzheimer' disease (AD). METHOD: Fifty patients with AD patients and 50 healthy subjects were examined by olfactory function T&T testing, OB volume and depth of OS assessed with Magnetic resonance imaging (MRI). RESULT: T&T olfactory testing revealed that AD patients had higher scores than control group (1.50 ± 0.17, 2.80 ± 0.31, P < 0.05). Bilateral and average OB volumes were smaller in AD group [(29.78 ± 5.17) mm3, (30.14 ± 4.87)mm3, (30.05 ± 5.08) mm3] than in control group [(36.65 ± 4.08)mm3, (36.56 ± 4.12)mm3, (36.46 ± 4.11)mm3] (P < 0.01). OS depth study revealed no statistical difference between AD patients and control groups (P > 0.05). Olfactory discriminate threshold was negatively correlated with average olfactory bulb volumes (r = -0. 711, P < 0.05), and was not correlated with depth of OS (r = -0.127, P > 0.05) in AD patients. CONCLUSION The OB volume were lower in AD patients as compare to controls, the depth of OS has no significant changes in AD patients; The OB volume is correlated with olfactory function, the depth of OS is no correlated with olfactory function. Cognitive impairment degree in AD patients is accordance with the lower degree olfactory function. The olfactory loss may be the earlier period and objective diagnosis indicator for AD patients.
Alzheimer Disease ; complications ; physiopathology ; Case-Control Studies ; Humans ; Magnetic Resonance Imaging ; Olfaction Disorders ; complications ; diagnosis ; Olfactory Bulb ; anatomy & histology

OBJECTIVE: To compare the consistency of four olfactory psychophysical test methods. METHOD: Twenty out-patients were done with olfactory psychophysical test and the results were analyzed. The four olfactory psychophysical test methods include simple test method, UPSIT, Sniffin Sticks test and the T&T olfactometer test. RESULT: The consistency of four test methods reached 85%, and UPSIT test can identify pseudo smell obstacles. CONCLUSION There is reliable and stable outcome of the four psychophysical olfactory test methods.
Adolescent ; Adult ; Female ; Humans ; Male ; Middle Aged ; Olfaction Disorders ; diagnosis ; Olfactometry ; methods ; Psychophysics ; Reference Values ; Smell ; Young Adult

BACKGROUNDSubjective olfactory tests are easy to perform and popularly applied in the clinic, but using only these, it is difficult to diagnose all disorders of the olfactory system. The olfactory event related potentials technique offers further insight into the olfactory system and is an ideal objective test. This analysis was of subjective and objective data on the olfactory function of twelve patients with loss of smell associated with an upper respiratory infection (URI).

METHODSWe tested the twelve patients with URI induced olfactory loss by medical history, physical examination of the head and neck, olfactory tests and medical imaging. Olfactory function was assessed by Toyota and Takagi olfactometry including olfactory detection and recognition thresholds and olfactory event-related potentials (OERPs) recorded with OEP-98C Olfactometer.

RESULTSAn unusual phenomenon was observed in five patients in whom the subjective detection and recognition thresholds were normal, while the expected OERPs were not detectable.

CONCLUSIONSWe suggest that the discordance between olfactory psychophysical measurements and OERPs might be the results of abnormal electrophysiology related with olfactory neuropathy caused by viral URI. In addition, the measurement of OERPs might play a significant role in evaluating olfactory dysfunction.

Adult ; Evoked Potentials ; Female ; Humans ; Male ; Middle Aged ; Olfaction Disorders ; diagnosis ; Respiratory Tract Infections ; complications ; Sensory Thresholds ; Smell ; physiology