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

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

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

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

OBJECTIVE: To explore changes of olfactory and gustatory functions in patients with olfactory dysfunction. METHOD: The 284 study subjects included 92 healthy volunteers, 92 with hyposmia and 100 with functional anosmia. Their olfactory and gustatory functions were examined using T&T olfactometer, olfactory event-related potentials (OERPs) and triple drop method, respectively. RESULT: The T&T results showed that the difference between patients with hyposmia and functional anosmia and healthy subjects had statistical significance. The OERPs results showed that patients with olfactory dysfunction had N1 and P2 waves of prolonged latency and reduced amplitude when compared to healthy subjects with the difference of statistical significance. When compared to healthy subjects, patients with olfactory dysfunction had clear hypogeusia and the difference had statistical significance. There was no significant difference between female and male groups. CONCLUSION It is suggested that the apparently concomitant hypogeusia is in patients with olfactory dysfunction. Decreased of olfactory and gustatory function exhibited little or no relationship with gender. Combined examinations of OERPs, T&T and triple drop method, could make it possible to reflect the overall chemical sensory functions in subjects systematically and provide scientific evidence for clinical diagnosis and treatment early.
Adolescent ; Adult ; Aged ; Ageusia ; diagnosis ; physiopathology ; Case-Control Studies ; Evoked Potentials ; Female ; Humans ; Male ; Middle Aged ; Olfaction Disorders ; diagnosis ; physiopathology ; Smell ; Taste ; Young Adult

OBJECTIVE: To analyses the clinical characteristics of 28 chronic rhino-sinusitis patients only characterized olfactory disorders. METHOD: Twenty-eight patients who have only olfactory disorder were diagnosed chronic rhino-sinusitis, among which 16 patients accepted intranasal budesonide for 15 days. All patients accepted CT scan, T&T test and olfactory event-related potentials test before and after treatment. RESULT: (1) No difference was found between 21 patients ( < or = 12 months) and 7 patients (>12 months) (P > 0.05), significant difference was found between maxillary sinus,ethmoid sinus and frontal sinus, sphenoid sinus in CT scan (P < 0.01). (2) Olfactory function improves after treatment (P < 0.01). Significant difference is found between 12 patients ( < or =12 months) and 4 patients (P < 0.01). CONCLUSION (1) Chronic rhino-sinusitis patients who have only olfactory disorder were found; (2) Intranasal budesonide treatment could improve olfactory functions of chronic rhino-sinusitis' patients.
Adult ; Aged ; Budesonide ; therapeutic use ; Chronic Disease ; Female ; Humans ; Male ; Middle Aged ; Olfaction Disorders ; diagnosis ; drug therapy ; etiology ; Olfactory Mucosa ; Sinusitis ; complications ; diagnosis ; drug therapy