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Background: Persistent olfactory dysfunction (OD) is a common symptom following SARS-CoV-2 infection that can greatly impact quality of life (QoL). Because coping strategies have been shown to moderate the effect of disease symptoms on functional and affective outcomes, this study aims to determine whether specific coping strategies are associated with and moderate QoL outcomes., Methodology: Participants with prior SARS-CoV-2 infection underwent psychophysical olfactory testing with Sniffin’ Sticks and completed questionnaires to elicit subjective olfactory function, coping strategies, olfactory-specific QoL, general QoL, and mental health., Results: There were 93 participants included in the study. Olfactory specific QoL scores were significantly worse among individuals with subjective and psychophysically measured OD compared to those with subjective and psychophysically confirmed normosmia. Olfactory-specific QoL, general QoL, and anxiety symptom scores were positively correlated with avoidant and disengagement coping among individuals with subjective and psychophysically measured OD. Depression symptom scores were positively correlated with avoidant and disengagement coping and negatively correlated with approach and engagement coping. There were no significant moderating effects on the association between olfactory performance and QoL or mental health screening assessment., Conclusions: Approach and engagement coping mechanisms are associated with improved depression, whereas avoidant and disengagement coping tracks with worse QoL and mental health screening assessment, offering an opportunity to counsel patients accordingly.

Background: Olfactory training (OT) has been shown to increase olfactory performance in healthy subjects and patients with post-traumatic or post-infectious olfactory loss. Morphological correlates such as olfactory bulb volume increase and gray matter changes suggest central changes in olfactory brain areas following olfactory exposure. Some evidence from animal studies indicates peripheral changes upon OT whereas no such data exist in humans. This study explores the question whether changes in olfaction following OT are associated with alterations of the electro-olfactogram (EOG) derived from the olfactory epithelium., Methodology: We compared electrophysiological EOG responses to a pleasant, rose-like odor (phenylethyl alcohol, PEA) and to an unpleasant odor (rotten eggs, H2S) in patients and controls. EOG were recorded in smell impaired patients before and after OT for a period of 4-6 months., Results: EOG recordings following PEA and H2S stimulation were significantly more often obtained in controls than in patients. OT was associated with a significantly higher number of EOG recordings., Conclusions: OT is associated with an increase in EOG responses implicating stimulus-induced plasticity to start at the level of the olfactory epithelium.

Background: Cross-modal chemosensory dysfunction between olfaction and gustation is not well known., Methodology: 180 participants were classified into three groups (60 with olfactory dysfunction, 60 with gustatory dysfunction and 60 healthy controls without chemosensory dysfunction). Olfactory functions were obtained with Sniffin Sticks; gustatory function was measured by suprathreshold gustatory stimuli (taste sprays) and a quasi-threshold measure of taste function (taste strips) for five taste qualities (sweet, salty, sour, bitter and umami). Electric taste threshold was measured using electrogustometry (EGM). In addition, group differences in dietary behaviors were investigated with a specifically designed questionnaire., Results: Patients with olfactory dysfunction had increased electric taste thresholds and decreased scores for the umami taste strip test as compared to healthy controls. Overall there was no major difference between patients with chemosensory dysfunction and healthy controls regarding dietary behaviors, although some patients certainly exhibited dietary problems. Importantly, patients with taste loss, but not patients with smell loss, exhibited a higher degree of depression than controls., Conclusion: Patients with olfactory dysfunction showed decreased taste sensitivity which suggested an interaction between the chemical senses taste, trigeminal function, and olfaction. This provides the basis for including both smell and taste psychophysical assessment in clinical practices. In addition, patients with taste loss appeared to suffer most from chemosensory dysfunction.

Background: Human nasal chemosensation is mediated by two separate, though interacting sensory pathways: the trigeminal and olfactory systems. Trigeminal sensitivity and olfacto-trigeminal interactions have not yet been well studied in idiopathic Parkinsons disease (IPD)., Objectives: The aim of this study was to assess odour detection thresholds in elderly IPD patients, and compare them to the odour detection thresholds of healthy controls. Finally, we investigated potential interactions between trigeminal and olfactory sensitivity., Methods: 89 IPD patients aged over 65 and 89 matched healthy participants were enrolled in the study. Odour detection thresholds to 3 stimuli differentially activating olfactory and trigeminal afferents (Phenyl-ethyl alcohol, n-Butanol and Pyridine) were assessed, using an ascending staircase, binary forced-choice procedure., Results and Conclusion: Detection threshold scores were able to discriminate between elderly IPD and controls. Pyridine was less effective than the two other odorants, suggesting that trigeminal pathway is less impaired than the olfactory system. We found that the detection thresholds were significantly different between IPD patients with good autonomy, and patients with impaired autonomy.

The neural plasticity of the olfactory system offers possibilities of treatment in terms of stimulation of the sense of smell, and different studies have suggested effectiveness of smell training, i.e., daily exposition to certain odors. To obtain reliable and precise estimates of overall treatment benefit on the olfactory function, we meta-analyzed the effects of smell training reported in 13 previous studies. We analyzed the smell training effectiveness across three different olfactory abilities, smell identification, discrimination and threshold for odor detection. We found a significant, positive effect of olfactory training for all olfactory abilities, with large effects of training on identification, discrimination and TDI-score and small-to-moderate effect in the case of threshold for odor detection. Interestingly, the pattern of results differed across Sniffin Sticks subtests depending on the origin of participants smell disorder, and the smell training duration influenced its effectiveness in the case of identification and the TDI score. Although the exact mechanism of olfactory recovery following the smell training still requires further investigation, our meta-analysis showed that such training should be considered an addition or alternative to existing smell treatment methods.

Background: Individuals with hyposmia, or the partial loss of smell, represent a large sector (15 %) of the population that is likely to grow with the current aging population; however, our understanding to how hyposmics centrally process odors is still not clear. One popular non-invasive tool for in vivo imaging of biological activity among human brains has been function magnetic resonance imaging (fMRI) which uses blood-oxygenation level dependent (BOLD) signal as an indirect measurement. Therefore, the aim of this study was to understand differences in olfaction processing between patients with hyposmia and healthy controls using functional magnetic resonance imaging (fMRI)., Methodology: Eleven hyposmic and 12 healthy, normosmic subjects were exposed to two different food-related odors (coffee and peach) during a block-designed fMRI session. Additionally, odor perception qualities were rated for each odor throughout the scanning session., Results: The activations of the normosmic group were localized in typical olfactory areas (insula, orbitofrontal cortex [OFC], limbic system and amygdala). The hyposmic group showed similar regions of activation (insula, OFC, limbic system), however, less activation was found in the amygdala, left anterior cingulate and right OFC, but higher activation was shown in the right parahippocampal and both the left and right posterior cingulate gyrus which are assumed to play an important role in the processing and remembrance of memories., Conclusions: These results indicate similar central olfactory processing among groups, yet subjects with partial loss may attempt to compensate smell impairment with odor memory or higher motivation to smell.

Background: The Sinonasal Outcome Test (SNOT-22) has been used as a patient reported outcome measure to grade symptom severity before and after treatment for chronic rhinosinusitis (CRS)., Methodology: This analysis uses data from the CRS Epidemiology Study (CRES). The overarching aim of CRES was to determine factors that influence the onset and severity of CRS. A study-specific questionnaire including SNOT-22 was distributed to patients with CRS attending ENT clinics across 30 centres in the United Kingdom. The aim of this analysis was to compare SNOT-22 scores between those with different types of CRS to determine any differences present in the total score or the subdomains and to assess whether any differences varied according to gender., Results: There were a total of 1249 CRS participants in the following subgroups: CRS without nasal polyps (CRSsNPs) (n=553), CRS with nasal polyps (CRSwNPs) (n=651), allergic fungal rhinosinusitis (AFRS) (n=45). Since there were differing gender ratios in each subgroup, males and females were analysed separately. The mean and standard deviation for SNOT-22 was: males CRSsNP 41.1 (21.0), CRSwNP 41.7 (20.5); females CRSsNP 49.6 (19.7), CRSwNP 49.5 (22.9). In the nasal domain, those with CRSwNP scored more highly than those with CRSsNP; for males 18.1 (8.1) vs. 15.9 (7.9); for females 19.6 (8.0) vs 16.7 (7.5)., Conclusions: Patients with CRSwNPs report higher symptom scores in the nasal domain of SNOT-22 than those with CRSsNPs with women in both subgroups reporting higher total scores than men.

Objectives: To assess subjective improvement of olfactory function following endoscopic sinus surgery (ESS) in chronic rhinosinusitis associated with nasal polyps (CRSwNP) and to analyse factors of recovery with the European Test of Olfactory Capabilities (ETOC)., Methods: We carried out a prospective study of 30 patients with CRSwNP from November 2011 to April 2013. The ETOC was filled the day before surgery and in the short term follow-up. Sixteen suprathreshold odorants with a detection task and a forced choice verbal identification task were tested., Results: The mean composite score (MCS) improved at 3 and 6 months. The preoperative MCS was correlated to the Lund-Mackay score and to the olfactory cleft opacification on preoperative computed tomography (CT) scan. Multivariate linear regression modelling of patients with preoperative anosmia showed that the olfactory recovery at 3 months was predicted by the preoperative Lund-Mackay score and the age, and at 6 months by the preoperative Lund-Mackay score., Conclusion: With a convenient psychophysical test, we showed that olfactory cleft opacification and CT scan score could be predictive factors of olfaction disorder severity and improvement after ESS in CRSwNP. These results need to be strengthened in the long term with a larger panel of patients.

Background: Past findings of an impact of cognitive impairment on awareness of olfactory dysfunction, and high prevalence of age-associated cognitive impairment motivated the present study of whether middle-aged and elderly adults are unaware of an olfactory dysfunction despite being carefully screened for cognitive impairment., Methodology: The sample included 203 Norwegian participants, aged 46-79 years, 134 women and 69 men, who underwent comprehensive neuropsychological assessment for screening of cognitive impairment. Subjective assessment of olfactory function ("How would you estimate your sense of smell?") was compared with outcome on objective assessment of olfactory function with the Scandinavian Odor Identification Test, which in the present study was shown to be valid for use on Norwegian populations., Results: We found that 79% of this cognitively healthy sample with objectively assessed olfactory dysfunction reported normal olfactory function (57% of functionally anosmics reported normal function). In contrast, only 9% with objectively assessed normal olfactory function reported olfactory dysfunction., Conclusion: A large proportion of cognitively well-functioning middle-aged and elderly adults with an olfactory dysfunction are unaware of their dysfunction. The ENT physician who suspects that the sense of smell may be compromised should, in addition to an anamnesis, assess the patient`s olfactory function objectively.

Background: This prospective study investigates the influence of primary Endoscopic Sinus Surgery (ESS) in patients with chronic rhinosinusitis (CRS) on olfactory function and on the patients' quality of life. We assess the role of preoperative disease severity measured by computed tomography (CT) scan in predicting outcome., Methodology: Adults undergoing ESS were examined preoperatively (n=92) and five months postoperatively. Coronal CT scans were evaluated referencing the Lund Mackay (LM) system. On the basis of the LM score, the collective was divided into two groups. We performed the olfactory test "Sniffin' Sticks" and handed out the specific health-related quality of life questionnaire SNOT-20., Results: We could demonstrate that olfactory function of patients with strong opacification on CT scans improved by an average of 2.49 points more than olfactory function of patients with less severe disease. In terms of the self-reported rating of smell, the degree of amelioration differed significantly. Both groups showed an improvement in quality of life irrespective of severity of disease., Conclusion: Mean olfactory function of patients with a high degree of disease in CT scan improved more than that of patients with less opacification on CT scan. Patient's subjective perception of smell impairment was in line with these findings.

Background: The effects of smoking on quality of life (QoL) results in chronic rhinosinusitis (CRS) patients still remain a matter of debate., Objective: To explore the impact of smoking on QoL and determine how quantity of daily smoking and duration affect QoL results after endoscopic sinus surgery (ESS)., Methodology: Patients with CRS were prospectively asked to evaluate their QoL pre- and after ESS. All subjects' QoL was evaluated by means of validated questionnaires either specific (Questionnaire of Olfactory Deficits), for assessing psychology (Zung Anxiety Scale, State -Trait Anxiety Inventory, Zung Depression Scale and Beck Depression Inventory) or generic (Short-Form-36). Smoking habits were expressed in pack-years., Results: No statistically significant differences were found in the pre-treatment scores in any of the questionnaires between smokers and non smokers. Post-operatively, all QoL questionnaires' results were significantly improved among both groups, although non smokers exhibited significantly greater improvement compared to smokers. There was a negative impact of the number of pack-years on the changes of QoL results; less improvement was observed as the number of pack-years was increasing., Conclusion: Although smoking did not improve preoperative QoL results and proved not to be a contra-indication factor for ESS regarding QoL, smokers presented worse treatment outcomes. Quantity and duration of smoking were significantly associated with worse postoperative results in all QoL questionnaires.

Background: The clinical usefulness of olfactory event-related brain potentials (OERPs) to assess olfactory function is limited by the relatively low signal-to-noise ratio of the responses identified using conventional time-domain averaging. Recently, it was shown that time-frequency analysis of the obtained EEG signals can markedly improve the signal-to-noise ratio of OERPs in healthy controls, because it enhances both phase-locked and non phase-locked EEG responses. The aim of the present study was to investigate the clinical usefulness of this approach and evaluate its feasibility in a clinical setting., Methodology: We retrospectively analysed EEG recordings obtained from 45 patients (15 anosmic, 15 hyposmic and 15 normos- mic). The responses to olfactory stimulation were analysed using conventional time-domain analysis and joint time-frequency analysis. The ability of the two methods to discriminate between anosmic, hyposmic and normosmic patients was assessed using a Receiver Operating Characteristic analysis., Results: The discrimination performance of OERPs identified using conventional time-domain averaging was poor. In contrast, the discrimination performance of the EEG response identified in the time-frequency domain was relatively high. Furthermore, we found a significant correlation between the magnitude of this response and the psychophysical olfactory score., Conclusion: Time-frequency analysis of the EEG responses to olfactory stimulation could be used as an effective and reliable diagnostic tool for the objective clinical evaluation of olfactory function in patients.

Background and Aim: Olfactory dysfunction is a common complaint in a large number of people. As the aetiologies of olfactory dysfunction vary greatly so do the treatment approaches. The aim of this retrospective study was to evaluate treatment with systemic corticosteroids, particularly focusing on its effectiveness on the different olfactory dysfunction aetiologies. Although a prospective randomized control trail is preferred for such an investigation, using the current approach, we were able to test a very large patient population., Material and Methods: A total of 425 patients with olfactory dysfunction were treated with systemic corticosteroids for 14 days. Olfactory performance was measured using the `Sniffin` Sticks` battery before and after the treatment., Results: The treatment with systemic corticosteroids significantly increased the performance on the TDI score and on each of the three subtests; threshold, discrimination and identification. In 26.6% of the patients improvement of more than six points of the TDI score was observed. The treatment proved to be more effective in patients with sinunasal olfactory dysfunction, where this percentage increased to 36.7, compared to other aetiologies. In addition, the increase in olfactory function was negatively correlated with the TDI score before the treatment., Conclusion: This study confirms the effectiveness of systemic corticosteroids on olfactory dysfunction in a large patient population. Specifically, the results show that treatment is: (a) more effective in patients with sinunasal than in patients with idiopathic olfactory dysfunction, (b) most effective in patients with sinunasal disease with nasal polyps, and (c), at best, effective in half of the patients. The current study may provide help in counselling patients.

Objectives: The olfactory bulb (OB) is a remarkably plastic structure with highly active afferent neurons, which is partly reflected by its volume. Although deterioration of olfaction after total laryngectomy is reported by many patients, this problem has not received widespread attention. There has been no study that had addresses this loss olfactory ability as a function of OB volume. The aim of this study was to determine OB volume changes after laryngectomy., Study Design: Twenty one patients post-total laryngectomy and 17 subjects with normal olfactory function underwent magnetic resonance imaging (MRI) for volumetric measurement of the OB. The history of all participants was taken in detail to exclude other possible causes of smell dysfunction. Volumetric measurement of the OB was performed by manual segmentation of the OB into coronal slices. Olfactory function was assessed with the orthonasal olfaction test., Results: There was no statistically significant difference in volume between the right and left sides of the OB in the study and control groups. However, the study group had smaller OB volumes than the control group. In our assessment of orthonasal olfaction, patients who were post-total laryngectomy had worse orthonasal olfactory function than the control group. There were significant correlations between OB volumes and orthonasal test scores., Conclusions: Our MRI study showed that post-total laryngectomy patients had higher rates of olfactory bulb atrophy than the control subjects. Laryngectomy is associated with measurable decreases in olfactory function and this study hopes to further clarify this association by demonstrating that patients with total laryngectomy have reduced OB volumes when compared to the normal population.

In clinical settings, olfactory testing is usually performed bilaterally; thus, unilateral olfactory loss may go unnoticed. The aims of this study were to evaluate 1) whether patients presenting with self-reported olfactory disorders demonstrate significant side differences in odour perception, depending on the prevalance of measured unilateral disorder, and 2) to evaluate the existing testing procedure. In 518 patients presenting with olfactory disorders, olfactory testing was performed using the "Sniffin' Sticks" test battery (consisting of a threshold, discrimination, and odour identification test) examining each nostril separately. According to the history and results from the clinical examination, olfactory disorders were classified as related to trauma, sinunasal disease, upper respiratory tract infection (URTI), tumour, congenital, idiopathic, and other. A difference of three or more points in one of the subtests or six or more points in the composite olfactory test score was considered a side difference. In almost one quarter of all presenting patients (23.4%), a side difference was detected. To not to miss lateralized disorders, we recommend testing each nostril separately. Depending on the presence or absence of a significant difference, testing then can be continued birhinally or separately for each nostril.

Necrotizing granulomatous inflammation of the upper respiratory tract is one of the hallmarks of Wegener's granulomatosis (WG), which may explain the reason for olfactory dysfunction in WG. However, a systematic analysis using modem olfactory testing tools has not been performed and potential causes of dysfunction at different levels of olfactory information processing remain obscure so far. In this study a group of 76 WG-patients was examined with sniffin'sticks screening 12, odour threshold (T)/discrimination (D)/identification (I) TDI-score, active anterior rhinomanometry and a standardized questionnaire for olfactory function. WG-patients were aware of their olfactory dysfunction, as proven by psychophysiological test results. An altered olfactory function was significantly correlated to local administration of mupirocin and to the time interval between first diagnosis and study entry. None of the other variables had a statistical significant effect on the olfactory dysfunction.

Aim: This prospective study aimed to assess treatment outcome on olfaction in patients undergoing Endoscopic Sinus Surgery (ESS) for nasal polyposis, and to evaluate the role of previous sinus surgery and the duration of olfactory deficit as prognostic factors for olfaction improvement., Methods: In total, 116 patients with nasal polyposis who underwent ESS were studied. Olfactory testing was performed using the Sniffin' Sticks test, preoperatively and 1-, 3- and 6-month postoperatively., Results: The values of the composite threshold discrimination identification score were significantly lower in patients with long duration of olfactory deficit and history of previous sinus surgery in all testing sessions. Adjustment for preoperative olfactory measures and all potential confounders revealed that both parameters remained strong independent predictors of normal olfactory function; a successful outcome was more frequent in patients with short duration of olfactory deficit and in patients who had not undergone previous sinus surgeries. However all patients achieved a significant stepwise increment of all indices of olfactory function over time, after ESS., Conclusions: Duration of olfactory deficit and previous sinus surgery presented highly significant predictive value for the short-term outcome of the olfactory function after ESS. However all patients suffering from nasal polyposis will probably improve olfaction significantly in a period up to six months after surgery.

The olfactory bulb collects the sensory afferents of the olfactory receptor cells located in the olfactory neuroepithelium. The olfactory bulb ends with the olfactory tract and is closely related to the olfactory sulcus of the frontal lobe. Many studies demonstrated that olfactory bulb volume assessed with magnetic resonance imaging is related to the olfactory function both in normal and pathological conditions. It has been shown that olfactory bulb volume changes with the degree of olfactory dysfunction, that it decreases with the duration of the olfactory loss and that patients with qualitative disorder such as parosmia have smaller olfactory bulbs than patients without parosmia. In this review, we will discuss the actual knowledge regarding olfactory bulb function, practical ways to measure olfactory bulb volume and olfactory sulcus depth, and report systematic observations regarding these measurements related to various causes of olfactory dysfunction, e.g. infection of the upper respiratory tract, head trauma, or neurodegenerative disease. Measurement of olfactory bulb volume may provide valuable information for patients with olfactory dysfunction.

Topic: Olfactory dysfunction may be assessed in the clinic with psychophysical testing and electrophysiological recording. Chemosensory event-related potentials (CSERPs) constitute an objective method to assess chemosensory function. Olfactory and trigeminal stimuli activate chemoreceptors from the olfactory neuroepithelium and from the nasal mucosa to evoke an electrophysiological response respectively called olfactory (OERPs) and trigeminal ERPs (TERPs). The purpose of this study is to assess the usefulness and feasibility of these diagnostic tools in the rhinology clinic and to correlate these results to the olfactory disorder aetiology., Materials and Methods: This study encompasses a cohort of 229 patients with a complaint of olfactory dysfunction from different origins. Orthonasal (Sniffing stick test with the treshold-discrimination-identification score: maximal score 48) and retronasal olfactory (maximal score 20) testing as well as CSERPs both after olfactory and trigeminal stimuli have been routinely performed. Olfactory dysfunction aetiologies were as follows: congenital (Cong.), chronic rhinosinusitis (CRS), idiopathic (Idiop.), post-medication (PM), neurologic (Neuro.), post-traumatic (PT) and post-infection (PI)., Results: Mean orthonasal and retronasal scores were respectively: 11.8 and 10.1 for Cong., 18.5 and 13.1 for CRS, 15.6 and 10.4 for Idiop., 15.3 and 10.2 for PM, 17 and 10.6 for Neuro., 15 and 9.9 for PT and 18.3 and 12 for PI. Correlations between orthonasal and retronasal scores were present for all subgroups except congenital and chronic rhinosinusitis subgroups. Orthonasal and retronasal scores were different (p < 0.05) when comparing CRS vs Cong., CRS vs PT and PT vs PI. Technical problems (olfactometer or olfactory stimulation, EEG amplifier,...) and patients discomfort (anxiety, stress,...) did not allow to draw any conclusion in 2 patients. Three patients after olfactory stimulus and 6 patients after trigeminal stimulus demonstrated too much eye blinking or muscular artifacts that did not allow us to perform electrophysiological analysis and averaging as 60% of artifact-free recording was not achieved. Olfactory ERPs were recorded in 28% of the patients and trigeminal ERPs were obtained in almost every patient (95%). There was no statistical difference between each subgroup regarding the presence or absence of OERPs., Conclusions: Psychophysical olfactory testing is a useful method to assess olfactory function in patients with olfactory loss and may help us to obtain a semi-objective and a basal evaluation of the olfactory performances. Feasibility and usefulness of CSERPs are also underlined in this study with only a limited number of patients who did not complete the examination. Psychophysical testing gives different results according to the aetiology of the olfactory disorder, which was not the case for electrophysiological recording. Olfactory acuity assessment should be based on psychophysical and CSERPs evaluation in a clinical setting.

The aim of this study was to compare the olfactory performance of anorectic patients and healthy controls with regard to the state of satiety. Using the Sniffin' Sticks, sensitivity to a nonfood odor (n-butanol) and to a food-related odor (isoamyl acetate) was assessed in 12 anorectic females and compared with 24 healthy controls. Threshold tests were performed in a hungry as well as in a satiated state, odor discrimination and odor identification only when satiated. Pleasantness of the odors was recorded. In terms of the non-food odor n-butanol, the olfactory sensitivity of anorectic patients and controls did not differ. Patients with anorexia nervosa had a significantly lower detection threshold for the food-related odor, but only in the hungry condition. Anorectic patients showed significant deficits in odor discrimination and identification, and under-evaluated the pleasantness of isoamyl acetate. Our results suggest an impaired projection from secondary to tertiary olfactory structures in anorexia nervosa, based upon the dichotomy of performance between detection threshold and odor discrimination/dentification. The reduced pleasantness of isoamyl acetate indicates a decreased olfactory responsiveness to food stimuli in anorexia nervosa.

Introduction: Sinus surgery is known to improve olfactory function in patients with nasal polyposis. However, little is known about the kinetics of this process., Material and Methods: Fifty-two adult patients with nasal polyposis underwent endonasal sinus surgery. Olfactory testing was performed with the Sniffin' Sticks assessing threshold (T), discrimination (D) and identification (I) giving the TDI score. Testing was performed 2 days prior to surgery (T1), as well as 1 week (T2), 1 month (T3), 3 months (T4), and 6 months (T5) following surgery., Results: The median TDI score was 15.4 (range 8.0-35.5) at T1, indicating that half the patients were anosmic before surgery, while 13.5% were normosmic. At T2, the median TDI score dropped to 8.0 (range 8.0-32.1). Thereafter, it improved to 21.7 (range 8.0-36.9) at T3 (p = 0.04), 22.8 (range 8.0-38.0) at T4 (p < 0.0005), and 27.0 (range 8.0-37.9) at T5 (p < 0.0005), respectively. 43.1% of patients were normosmic at T5, however, 21.6% remained anosmic. Each subtest followed the same pattern. No significant effect on the kinetics of olfactory function could be found for variables such as systemic steroids, partial resection of the middle turbinate, inferior turbinotomy, and allergic rhinitis., Conclusion: Endonasal sinus surgery significantly improved the severely impaired olfactory function in patients with nasal polyposis. Olfactory function dropped shortly after surgery, and subsequently increased steadily up to the endpoint of the study 6 months postoperatively.

Objective: There are mutual interactions between the olfactory and trigeminal systems. The purpose of this study was (1) to assess trigeminal sensitivity using chemosensory event-related potentials (CSERPs) in patients with olfactory dysfunction and (2) to evaluate whether trigeminal ERPs were different with regard to the presence or absence of olfactory ERPs., Materials and Methods: Prospective study of 60 patients who presented with olfactory dysfunction (postinfectious olfactory loss: n = 19, posttraumatic olfactory loss: n = 28, and olfactory loss due to idiopathic, or toxic causes: n = 13). All patients were extensively evaluated with an orthonasal olfactory test based on the "Sniffin' Sticks". In addition, chemosensory ERPs were recorded in response to olfactory and trigeminal stimulation., Results: Olfactory/trigeminal ERPs were recorded in 25/60 patients, respectively. Patients with no detectable olfactory ERPs, considered as severely affected, demonstrated an altered trigeminal sensitivity as indicated by an increase in P2 latencies and a decrease in both, P2 and N1-P2 amplitudes compared to patients with detectable olfactory ERPs. A regression analysis showed a negative relation between P2 latencies and the "Sniffin' Sticks"score (r = -0.46, p < 0.001)., Conclusions: Patients with severe olfactory dysfunction demonstrated decreased trigeminal sensitivity as indicated by electrophysiological measures. This study supports the idea of interactions between the chemical senses. Whether altered responses to trigeminal stimulation may be used as a prognostic measure related to recovery from olfactory loss remains to be demonstrated.

Background: Despite the common occurrence of rhinological pathology presenting to the ENT clinic, routine testing of olfactory ability is rarely performed., Objectives: The aim of this study was to determine the role of routine olfactory testing., Methods: This was a prospective study conducted in the outpatient clinic of a district general hospital. Patients presenting with rhinological complaints had their olfactory status assessed using the combined olfactory test (COT) before and after rhinological surgery., Results: Eighty patients (56 men, 24 women) had tests completed over a 12-month period. Patients assessed mostly had nasal polyposis, chronic rhinosinusitis or septal deformity. 83% of patients had either a complaint of olfactory disturbance or a COT score of 6 or less, or had both; but correlation between symptoms and scores was poor. Post-operative COT scores showed significant improvement (p = 0.02) with post-septoplasty patients showing the most significant improvement as a group (p = 0.001)., Conclusions: Olfactory disturbance is very common in rhinological pathology and the patient's history alone cannot be relied upon. Simple olfactory assessment, such as with the combined olfactory test, is easy to perform and cheap to use and should be a commonly used resource in the ENT clinic. Formal testing can help to document any pre-existing olfactory loss and any post-operative changes as well as detecting unreported hyposmia.

Objectives: Effects of smoking on olfaction appear to be well-known. However, there are not many studies that studied these effects on the basis of olfactory testing, and no studies on this topic have been performed so far in an Asian population. Thus, the aim of this study was to investigate the effects of smoking on odour identification., Methods: Five hundred fifty seven Japanese subjects (368 men and 189 women) were given the cross-cultural smell identification test (CC-SIT). Their history was taken with special regard to nasal disease and smoking. Urine nicotine level was assessed in 107 subjects., Results: The CC-SIT scores of current and previous smokers were lower than those of nonsmoking subjects (p < 0.05). The Brinkman index (BI) and CC-SIT score were correlated even when controlling for the subjects' age (r = -0.24, p < 0.001). The time since quitting cigarette smoking did not exhibit a relation with the CC-SIT score (r = -0.04, p = 0.76). In addition, urine levels of nicotine and its metabolites exhibited no significant correlation with the CC-SIT score (r = -0.08, p = 0.40)., Conclusion: Smoking reduces olfactory function. Apparently, recovery of olfactory sensitivity after cessation of smoking appears to be exceptional.

Aim: In this prospective study the effect of medical and surgical treatment on subjective olfaction was studied in patients with nasal polyposis (NPS). The effects on nasal obstruction, anterior and posterior rhinorrhea, sneezing and itching are reported in another article in this issue., Patients and Methods: Protocol 1. Twenty-four patients with NPS who complained about anosmia were treated with a 7-days course of systemic steroids. Their subjective overall sense of smell was determined with a visual analog scale (VAS) before treatment, immediately after treatment, and two months later. Subsequently all patients underwent surgery bilaterally according to the nasalization principles. The sense of smell was re-evaluated at 1, 3, 6, 9, and 12 months postoperatively. Protocol 2. Thirty-two patients with NPS not responding to medical therapy who, for different reasons, did not receive oral steroid treatment, received surgery only and were followed up during one year after nasalization. Of these patients, 25 were anosmic and 7 normosmic., Results: Protocol 1. Following the 7-day treatment with systemic steroids the olfactory score increased significantly. During the waiting time for surgery (64 +/- 39 days) this score deteriorated again in a significant way. One month after nasalization which included a depot injection of triamcinolone 80 mg the day after surgery, the olfactory score ameliorated again and remained stable at 3, 6, 9, and 12 months. None of the patients reported any intake of systemic steroids during the one-year of follow-up. Statistically, there was a trend suggesting that the 12 month post-nasalization score was better than the immediate post-oral steroid score. A good correlation between the improvement of the sense of smell after 7 days of systemic steroids and one year after nasalization was found. Protocol 2 One month after the nasalization protocol, olfaction in patients of the hypo-anosmic group had improved considerably. Scores at 3, 6, 9, and 12 remained very stable. The sense of smell in the normosmic group did not change after surgery and remained stable during the year of follow-up. In total, 49 patients with a severe loss of smell showed a significant improvement at 12 months after surgery., Conclusion: The present study shows that 1) long-lasting correction of olfactory dysfunction produced by nasal polyposis can be achieved through the combination of nasalization and low dose of nasal steroids, 2) middle turbinate resection does not alter the possibilities to restore the sense of smell.

The purpose of this study is to investigate the existing relations between olfaction and acquisition of the two-way conditioned avoidance response (CAR). For this investigation we have used white adult male Wistar rats. Taking into consideration that several structures of the limbic system participate in learning and memory processes and also that olfactory pathway is believed to have connections with the limbic system, we thought it would be interesting to investigate, if peripheral anosmia influences the performance of rats in the two-way avoidance response. It was shown that peripheral anosmia in rats impaired conditioned avoidance response.