CONCLUSIONS: We have provided an overview of current evidence and expert-agreed recommendations for the definition, investigation, and management of OD. As for our original Position Paper, we hope that this updated document will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency, and generalisability of work in this field.
METHOD: This study included a total of 44 participants without subjective olfactory disturbances. Lavender and normal saline were used as the olfactory stimulant and control. Electroencephalogram was recorded and power spectra were analysed by the spectral analysis for each alpha, beta, delta, theta and gamma bandwidth frequency upon exposure to lavender and normal saline independently.
RESULTS: The oscillatory brain activities in response to the olfactory stimulant indicated that the lavender smell decreased the beta activity in the left frontal (F7 electrode) and central region (C3 electrode) with a reduction in the gamma activity in the right parietal region (P4 electrode) (p < 0.05).
CONCLUSION: Olfactory stimulants result in changes of electrical brain activities in different brain regions, as evidenced by the topographical brain map and spectra analysis of each brain wave.
METHOD: For this purpose, we employ fractal theory and analyze the variations of fractal dimension of GSR and EEG signals when subjects are exposed to different olfactory stimuli in the form of pleasant odors.
RESULTS: Based on the obtained results, the complexity of GSR signal changes with the complexity of EEG signal in case of different stimuli, where by increasing the molecular complexity of olfactory stimuli, the complexity of EEG and GSR signals increases. The results of statistical analysis showed the significant effect of stimulation on variations of complexity of GSR signal. In addition, based on effect size analysis, fourth odor with greatest molecular complexity had the greatest effect on variations of complexity of EEG and GSR signals.
CONCLUSION: Therefore, it can be said that human skin reaction changes with the variations in the activity of human brain. The result of analysis in this research can be further used to make a model between the activities of human skin and brain that will enable us to predict skin reaction to different stimuli.
METHODS: This was a cross-sectional study, conducted at Otorhinolaryngology outpatient clinic of Universiti Kebangsaan Malaysia Medical Centre, Secondary Science School, and Children Learning Centre in Kuala Lumpur, Malaysia, from August 2019 until December 2021.
RESULTS: In 450 healthy participants, the cut-off points of the threshold discrimination identification (TDI) scores at the 10th percentile for olfactory abilities were 19 in children, 30.1 in adolescents, 32.1 in young adults, 31.1 in middle-aged adults, and 28.6 in older adults. The children had significantly lower olfactory abilities, with the Bonferroni post-hoc tests of p<0.001. The young adults had higher olfactory abilities than older adults (p<0.05). The results showed that the identification score was highest in middle-aged adults (p<0.001). The discrimination score was the highest in young adults (p<0.001). The best odor threshold performance was observed in adolescents (p<0.001). The TDI score showed a significant difference in olfactory abilities between men and women (p=0.001).
CONCLUSION: Using a culturally adapted smell test, our population was able to identify, discriminate, and perceive odorants better than the European population. This data will help clinicians and researchers with a tool to reliably establish the correct results of olfactory function in our population. Women had better olfactory abilities than men.
Materials and Methods: The odorant descriptors and distractors of the original version of Sniffin' Sticks were translated into Malay language. It was then tested for familiarity and identifiability in 30 normosmic subjects. The descriptors were replaced until the familiarity of all descriptors and identification rates of odorants achieved ≥ 70%. The validity of the new cultural-adapted version was tested in 60 hypo-anosmic subjects and 60 normosmic subjects with Student t-test. The test-retest reliability was evaluated after two weeks with interclass correlation.
Results: Two odorant descriptors and nine distractors achieved familiarity <70% (13.3% - 66.7%) and were replaced. Another three culturally inappropriate distractors were also replaced. The mean score among the healthy subjects was significantly higher than the subject with smell dysfunction [13.7 (1.12) and 7.3 (3.42); t = 7.24 (df = 34.23), P<0.001]. The coefficient of correlation (r) between test and retest scores was 0.93 (P<0.001).
Conclusion: The cultural adapted Malaysian version of Sniffin' Sticks smell identification test is valid and has high test-retest reliability. This is the first smell identification test validated in Malaysia. It is effective for evaluation of olfactory function in local population.
METHODS: In this case-control observational study, 32 adults with post-TBI olfactory dysfunction (cases) were matched with 32 TBI patients with intact olfactory function (controls). All subjects self-rated their olfactory function using the Visual Analogue Scale (VAS). Cases also underwent objective olfactory function assessment with the Sniffin' Sticks test, which generated a Threshold, Discrimination, and Identification (TDI) score. QoL was assessed with the Questionnaire for Olfactory Disorders (QOD). Factors evaluated included age, gender, smoking, TBI severity and duration, lesion localisation, and Disability Rating Scale (DRS) score.
RESULTS: Cases had a higher mean QOD score than controls at 26.31 ± 14.37 and 9.44 ± 8.30, respectively (F = 16.426, p smell changes, adapting to smell changes, and fear of hazardous substance exposure. DRS score and severity of olfactory dysfunction significantly affected QoL (p
METHODS: A cross-sectional study involving patients with coronavirus disease 2019 self-perceived as asymptomatic was conducted. Assessments included the subjective Malaysian Smell and Taste Questionnaire and the culturally adapted Malaysian version of the objective Sniffin' Sticks Identification smell test.
RESULTS: In 81 participants (mean age of 31.59 ± 12.04 years), with mean time from diagnosis to smell test of 7.47 ± 3.79 days, subjective assessment showed that 80.2 per cent were asymptomatic (questionnaire score of 6) and 19 per cent had mild symptoms (questionnaire score of 7 and 8). The mean objective smell test score was 10.89 ± 2.11. The prevalence of olfactory impairment was 76.6 per cent among patients with coronavirus disease 2019 self-perceived as asymptomatic. There was no association between the questionnaire and the smell test scores (p = 0.25). There was a correlation between the smell test score and the duration from diagnosis to smell test (p = 0.04).
CONCLUSION: The objective assessment demonstrated that coronavirus disease 2019 patients who perceived themselves as asymptomatic showed olfactory impairment.
MATERIALS AND METHODS: OS depth was obtained using T1 magnetic resonance imaging scans. Participants (mean age ± sd = 57 ± 16 years, ranging from 20 to 80 years) were screened for olfactory function using the Sniffin' Sticks Screening 12 test. They were divided into an olfactory dysfunction group (n = 604) and a normosmia group (n = 493). Participants also completed questionnaires measuring depression, anxiety and quality of life.
RESULTS: The right OS was deeper than the left side in all age groups. On the left side, women had deeper OS compared with men, exhibiting a higher degree of symmetry in left and right OS depth in women. Variance of olfactory function was largely determined by age, OS depth explained only minor portions of this variance. Normative data for minimum OS depth was 7.55 mm on the left and 8.78 mm on the right for participants aged between 18 and 35 years (n = 144), 6.47 mm on the left and 6.99 mm on the right for those aged 36-55 years (n = 120), and 5.28 mm on the left and 6.19 mm on the right for participants older than 55 years (n = 222).
CONCLUSION: Considering the limited resolution of the presently used T1 weighted MR scans and the nature of the olfactory screening test, OS depth explained only minor portions of the variance of olfactory function, which was largely determined by age. Age-related normative data of OS depth are presented as a reference for future work.
METHODS: This is a prospective cross-sectional study conducted at the University Malaya Medical Centre. A total of 30 patients who have undergone total laryngectomy were assessed objectively using the Sniffin' Sticks test and compared against normal age-matched Malaysians. Subsequently, they also filled out the modified Questionnaire on Olfactory Disorders. Correlations of patient demographics, disease and treatment variables against olfactory outcomes were conducted.
RESULTS: All subjects suffered olfactory impairment, with 66.7% of them being anosmic after total laryngectomy. The Sniffin' Sticks test demonstrated a statistically significant difference between laryngectomees and the normal age-matched Malaysian population in all three subtests for odor threshold, discrimination and identification. 37% of patients developed olfactory adaptive methods, which resulted in higher olfactory scores and a better quality of life. There were no patient demographics, disease or treatment variables associated with a poorer olfactory outcome identified.
CONCLUSION: Olfactory impairment should not be overlooked among patients after total laryngectomy. Although as many as a third of patients developed some sort of olfactory adaptive behavior, early rehabilitation should be integrated into the multidisciplinary rehabilitation program after total laryngectomy.