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Thomas Hummel - One of the best experts on this subject based on the ideXlab platform.
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prevalence and correlates of Parosmia and phantosmia among smell disorders
Chemical Senses, 2021Co-Authors: Jane K Parker, Christine E. Kelly, Robert Pellegrino, Joel D Mainland, Thomas HummelAbstract:Among those many individuals who experience a reduced odor sensitivity (hyposmia/anosmia) some individuals also have disorders that lead to odor distortion, such as Parosmia (i.e., distorted odor with a known source), or odor phantoms (i.e., odor sensation without an odor source). We surveyed a large population with at least one olfactory disorder (N = 2031) and found that odor distortions were common (46%), with respondents reporting either Parosmia (19%), phantosmia (11%), or both (16%). In comparison to respondents with hyposmia or anosmia, respondents with Parosmia were more likely to be female, young, and suffering from post-viral olfactory loss (p < 0.001), while respondents with phantosmia were more likely to be middle-aged (p < 0.01) and experiencing symptoms caused by head trauma (p < 0.01). In addition, Parosmia, compared to phantosmia or anosmia/hyposmia, was most prevalent 3 months to a year after olfactory symptom onset (p < 0.001), which coincides with the timeline of physiological recovery. Finally, we observed that the frequency and duration of distortions negatively affects quality of life, with Parosmia showing a higher range of severity than phantosmia (p < 0.001). Previous research often grouped these distortions together, but our results show that they have distinct patterns of demographics, medical history, and loss in quality of life.
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prevalence and correlates of Parosmia and phantosmia among smell disorders
medRxiv, 2021Co-Authors: Robert Pellegrino, Jane K Parker, Christine E. Kelly, Joel D Mainland, Thomas HummelAbstract:Among those many individuals who suffer from a reduced odor sensitivity (hyposmia/anosmia) some individuals also experience disorders that lead to odor distortion, such as Parosmia (i.e., distorted odor with a known source), or odor phantoms (i.e., odor sensation without an odor source). We surveyed a large population with at least one olfactory disorder (N = 2031) and found that odor distortions were common (46%), with respondents reporting either Parosmia (19%), phantosmia (11%), or both (16%). In comparison to respondents with hyposmia or anosmia, respondents with Parosmia were more likely to be female, young, and suffered from post-viral olfactory loss (p < 0.001), while phantosmia occurred most frequently in middle-aged respondents (p < 0.01) and was more likely to be caused by head trauma than Parosmia (p < 0.01). A higher prevalence of odor distortion was observed 3 months to a year after their olfactory symptom onset (p < 0.001), which coincides with the timeline of physiological recovery. Additionally, we observed that the frequency and duration of distortions negatively affects quality of life, with Parosmia showing a higher range of severity than phantosmia (p < 0.001). Previous research often grouped these distortions together, but our results show that they have distinct patterns of demographics, medical history, and loss in quality of life.
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intranasal sodium citrate in quantitative and qualitative olfactory dysfunction results from a prospective controlled trial of prolonged use in 60 patients
European Archives of Oto-rhino-laryngology, 2021Co-Authors: Antje Haehner, Katherine L Whitcroft, N Gunder, Mandy Cuevas, Peter Andrews, S Menzel, Thomas HummelAbstract:We have previously shown that treatment with intranasal sodium citrate may be beneficial in post-infectious olfactory dysfunction. Sodium citrate reduces free intranasal calcium and is, therefore, thought to prevent calcium-mediated feedback inhibition at the level of the olfactory receptor. We aimed to determine whether treatment with a 2-week course of intranasal sodium citrate improves quantitative olfactory function in patients with post-infectious impairment. We also aimed to determine whether sodium citrate is beneficial in treating qualitative olfactory dysfunction. We performed a prospective, controlled study. Patients applied intranasal sodium citrate solution to the right nasal cavity for 2 weeks. The left nasal cavity was untreated and, therefore, acted as an internal control. Monorhinal olfactory function was assessed using the “Sniffin’ Sticks” composite ‘TDI’ score, before and after treatment. The presence of Parosmia and phantosmia was also assessed. Overall, there was a significant increase in TDI after treatment (using the best of right and left sides). Treatment with sodium citrate did not significantly improve quantitative olfactory function, compared to control. The proportion of patients reporting Parosmia did not change significantly after treatment. However, there was a significant reduction in the proportion of patients reporting phantosmia, at the end of the study period. Treatment with intranasal sodium citrate for a period of 2 weeks does not appear to improve quantitative olfactory function in patients with post-infectious impairment, compared to control. It may, however, be beneficial in treating phantosmia, which should be further addressed in future work.
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Parosmia is Associated with Relevant Olfactory Recovery After Olfactory Training.
The Laryngoscope, 2020Co-Authors: David T. Liu, Carl Philpott, Maha Sabha, Michael Damm, Anna Oleszkiewicz, Antje Hähner, Thomas HummelAbstract:OBJECTIVE/HYPOTHESIS This study aims to determine the association between Parosmia and clinically relevant recovery of olfactory function in patients with post-infectious olfactory dysfunction (PIOD) receiving olfactory training. STUDY DESIGN Retrospective cohort study. METHODS This was a retrospective cohort study of patients with PIOD that received olfactory training. Adult patients with the major complaint of quantitative smell loss were recruited and treated at several ENT clinics in German between 2008 and 2018. The outcome was based on the association between smell-loss related factors (including Parosmia and phantosmia) and clinically relevant changes in overall and subdimension olfactory function of threshold, discrimination, and identification using binary logistic regression analysis. RESULTS A total of 153 participants with PIOD were included. Clinically relevant improvements in overall olfactory function were more likely in those that had lower baseline olfactory function. Relevant improvements in discrimination function were more likely in those that had lower baseline olfactory function and those that had Parosmia at the initial visit. Similarly, relevant improvements in odor identification were more likely in those that had a lower baseline olfactory function and in those who had Parosmia at the first visit. Clinically significant improvements in odor threshold were more likely in those who were older in age. CONCLUSIONS This study demonstrated that the presence of Parosmia is associated with clinically relevant recovery in olfactory discrimination and identification function in patients with PIOD receiving olfactory training. LEVEL OF EVIDENCE 4 Laryngoscope, 131:618-623, 2021.
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Parosmia is associated with relevant olfactory recovery after olfactory training
2020Co-Authors: David T. Liu, Antje Haehner, Carl Philpott, Maha Sabha, Michael Damm, Anna Oleszkiewicz, Thomas HummelAbstract:Objectives This study aims to determine the association between Parosmia and clinically relevant recovery in olfactory function in patients with smell loss receiving olfactory training. Design and setting This was a retrospective cohort study of patients that received olfactory training. Adult patients with the major complaint of quantitative smell loss were recruited and treated at several ENT clinics in German between 2008 and 2018. Participants A total of 243 participants were included. Main outcome measures Changes in olfactory function after olfactory training. Age, gender, baseline olfactory function, etiology and duration of smell loss, duration of training, and presence of Parosmia and phantosmia were assessed for their impact on clinically relevant changes in overall and subdimension olfactory function using binary logistic regression analysis. Results Relevant improvements in discrimination function were more likely in those that had lower baseline olfactory function, postinfectious reasons compared to posttraumatic or idiopathic causes and those that had Parosmia at initial visit. Relevant improvements in odour identification were more likely in those that had a lower baseline olfactory function, female gender, and in those who had Parosmia at the first visit. Clinically significant improvements in odour threshold were more likely in postinfectious causes compared to posttraumatic reasons and those who were older in age. Conclusions This study demonstrated that the presence of Parosmia is associated with clinically relevant recovery in olfactory function in patients with smell loss receiving olfactory training.
Philippe Rombaux - One of the best experts on this subject based on the ideXlab platform.
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Brain lesion-pattern analysis in patients with olfactory dysfunctions following head trauma
NeuroImage. Clinical, 2016Co-Authors: Jörn Lötsch, Philippe Rombaux, Alfred Ultsch, Maren Eckhardt, Caroline Huart, Thomas HummelAbstract:The presence of cerebral lesions in patients with neurosensory alterations provides a unique window into brain function. Using a fuzzy logic based combination of morphological information about 27 olfactory-eloquent brain regions acquired with four different brain imaging techniques, patterns of brain damage were analyzed in 127 patients who displayed anosmia, i.e., complete loss of the sense of smell (n = 81), or other and mechanistically still incompletely understood olfactory dysfunctions including Parosmia, i.e., distorted perceptions of olfactory stimuli (n = 50), or phantosmia, i.e., olfactory hallucinations (n = 22). A higher prevalence of Parosmia, and as a tendency also phantosmia, was observed in subjects with medium overall brain damage. Further analysis showed a lower frequency of lesions in the right temporal lobe in patients with Parosmia than in patients without Parosmia. This negative direction of the differences was unique for Parosmia. In anosmia, and also in phantosmia, lesions were more frequent in patients displaying the respective symptoms than in those without these dysfunctions. In anosmic patients, lesions in the right olfactory bulb region were much more frequent than in patients with preserved sense of smell, whereas a higher frequency of carriers of lesions in the left frontal lobe was observed for phantosmia. We conclude that anosmia, and phantosmia, are the result of lost function in relevant brain areas whereas Parosmia is more complex, requiring damaged and intact brain regions at the same time.
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Olfactory bulb volume in the clinical assessment of olfactory dysfunction.
Rhinology, 2009Co-Authors: Philippe Rombaux, Thierry Duprez, Thomas HummelAbstract: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.
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Post-infectious olfactory loss: a cohort study and update.
B-ent, 2009Co-Authors: Philippe Rombaux, Caroline Huart, Stephane Martinage, Stéphanie ColletAbstract:Post-infectious olfactory loss is defined as an olfactory dysfunction in the course of an upper respiratory tract infection. Quantitative olfactory dysfunction is usually moderate to severe, with many patients experiencing a qualitative disorder such as Parosmia. Diagnosis is made on the basis of patient history, normal clinical examination (no inflammatory disease in the olfactory cleft) and decreased olfactory function. This paper provides an update of pathophysiology, clinical management and prognosis, and also looks at the clinical characteristic of a cohort of 122 patients from our department. Results from orthonasal and retronasal testing, chemosensory event-related potentials and olfactory bulb volume confirmed previous findings: our post-infectious olfactory patients were middle-aged women (sex ratio 2.4; mean age 53.9), with 47.5% and 18% of them complaining of Parosmia and phantosmia respectively. More of them were hyposmic than anosmic (64.7% and 35.3% respectively) and 18 suffered repeat episodes. Olfactory bulb volume was correlated to psychophysical olfactory testing and orthonasal to retronasal scores. Olfactory-event-related potentials were found in about one-third of the patients and the vast majority of them had reproducible intranasal trigeminal event-related potentials. As there is no proven medical therapy for this disease, complete clinical evaluation of the patients may help to counsel patients about the recovery prognosis that applies to one-third of them.
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Olfactory Function and Olfactory Bulb Volume in Patients with Postinfectious Olfactory Loss
Laryngoscope, 2006Co-Authors: Philippe Rombaux, Georges Nicolas, Bernard Bertrand, André Mouraux, Thierry Duprez, Thomas HummelAbstract:OBJECTIVE: The study aimed to investigate whether the degree of postinfectious olfactory loss is reflected in volume of the olfactory bulb (OB). STUDY DESIGN: Retrospective study of 26 patients with postinfectious olfactory loss. MATERIALS AND METHODS: Olfactory function was assessed with the "Sniffin' Sticks" test kit, and the magnetic resonance imaging study focused on OB volume and the olfactory sulcus. RESULTS: The study revealed that 1) OB volume varies with regard to olfactory function, 2) OB volume decreases with duration of olfactory loss, and 3) patients with Parosmia had smaller OB volumes than patients who did not report such smell distortions, although their overall olfactory function was not significantly different from each other. CONCLUSION: The study emphasizes that OB volume is a gauge of olfactory function.
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Assessment of olfactory function using orthonasal and retronasal testing, Magnetic Resonance Imaging and chemosensory event related potentials
2006Co-Authors: Philippe RombauxAbstract:Numerous techniques are useful to assess olfactory function in healthy subjects and patients with olfactory disorders. Psychophysical measurements have been developped using standardized tests which stimulate the chemoreception with an orthonasal or a retronasal routes. Electrophysiological recording are considered as a method relying to a lesser degree on the subject's cooperation and are based on chemosensory event related potentials; CSERP. More recently, MRI and functional MRI have been developed to assess the morphology of the olfactory apparatus as well as the cortical or subcortical area activated after a chemosensory stimulus. Psychophysical and electrophysiological measurements may help to identify a quantitative deficit (anosmia, hyposmia) altough some methods are currently being developed to assess qualitative dysfunction such as Parosmia and phantosmia. In rhinology unit, patients usually present an olfactory dysfunction related to a sinunasal disorder for which medical and/or surgical treatment exist or related to a sensorineural disorder where olfactory neuroepithelium and olfactory apparatus have been injured and for which no therapy had proven its efficacy. This work encompasses the clinical application of CSERP, the measurement of the olfactory bulb in some disease, the lateralisation of trigeminal responses and finally the relation between these measurements for the rhinologic clinic.
Laurie A Miller - One of the best experts on this subject based on the ideXlab platform.
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olfactory dysfunction in temporal lobe epilepsy a case of ictus related Parosmia
Epilepsy & Behavior, 2007Co-Authors: Sarah Jacek, Richard J Stevenson, Laurie A MillerAbstract:Abstract Olfactory abnormalities in temporal lobe epilepsy (TLE) usually involve either brief hallucinations prior to seizures or chronic impairments in odor discrimination and identification. We describe the case of a man (B.C.) with TLE with an unusual presentation, an ictus-related Parosmia. B.C. reported distorted perception of odor quality and hedonics that could provoke nausea and gagging, typically at its most extreme in the week or so following a seizure. Measures of B.C.’s olfactory functioning were obtained at stages of the ictal cycle when Parosmia symptoms were severe and when they had decreased. Unlike other parosmics, B.C.’s detection thresholds were always normal, and unlike others with TLE, he evidenced little impairment in identification or discrimination. Testing during a period of more severe Parosmia suggested that B.C.’s experiences might be the result of hedonic changes. We argue this may be the effect of seizure activity on the amygdala, which is known to be involved in mediating emotive reactions to odors.
David T. Liu - One of the best experts on this subject based on the ideXlab platform.
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Parosmia is Associated with Relevant Olfactory Recovery After Olfactory Training.
The Laryngoscope, 2020Co-Authors: David T. Liu, Carl Philpott, Maha Sabha, Michael Damm, Anna Oleszkiewicz, Antje Hähner, Thomas HummelAbstract:OBJECTIVE/HYPOTHESIS This study aims to determine the association between Parosmia and clinically relevant recovery of olfactory function in patients with post-infectious olfactory dysfunction (PIOD) receiving olfactory training. STUDY DESIGN Retrospective cohort study. METHODS This was a retrospective cohort study of patients with PIOD that received olfactory training. Adult patients with the major complaint of quantitative smell loss were recruited and treated at several ENT clinics in German between 2008 and 2018. The outcome was based on the association between smell-loss related factors (including Parosmia and phantosmia) and clinically relevant changes in overall and subdimension olfactory function of threshold, discrimination, and identification using binary logistic regression analysis. RESULTS A total of 153 participants with PIOD were included. Clinically relevant improvements in overall olfactory function were more likely in those that had lower baseline olfactory function. Relevant improvements in discrimination function were more likely in those that had lower baseline olfactory function and those that had Parosmia at the initial visit. Similarly, relevant improvements in odor identification were more likely in those that had a lower baseline olfactory function and in those who had Parosmia at the first visit. Clinically significant improvements in odor threshold were more likely in those who were older in age. CONCLUSIONS This study demonstrated that the presence of Parosmia is associated with clinically relevant recovery in olfactory discrimination and identification function in patients with PIOD receiving olfactory training. LEVEL OF EVIDENCE 4 Laryngoscope, 131:618-623, 2021.
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Assessment of odor hedonic perception: the Sniffin’ sticks Parosmia test (SSParoT)
Scientific Reports, 2020Co-Authors: David T. Liu, Antje Welge-lüssen, Gerold Besser, Christian A. Mueller, Bertold RennerAbstract:Qualitative olfactory dysfunction is characterized as distorted odor perception and can have a profound effect on quality of life of affected individuals. Parosmia and phantosmia represent the two main subgroups of qualitative impairment and are currently diagnosed based on patient history only. We have developed a test method which measures qualitative olfactory function based on the odors of the Sniffin’ Sticks Identification subtest. The newly developed test is called Sniffin’ Sticks Parosmia Test (SSParoT). SSParoT uses hedonic estimates of two oppositely valenced odors (pleasant and unpleasant) to assess hedonic range (HR) and hedonic direction (HD), which represent qualitative olfactory perception. HR is defined as the perceivable hedonic distance between two oppositely valenced odors, while HD serves as an indicator for overall hedonic perception of odors. This multicenter study enrolled a total of 162 normosmic subjects in four consecutive experiments. Cluster analysis was used to group odors from the 16-item Sniffin’ Sticks Identification test and 24-additional odors into clusters with distinct hedonic properties. Eleven odor pairs were found to be suitable for estimation of HR and HD. Analysis showed agreement between test–retest sessions for all odor pairs. SSparoT might emerge as a valuable tool to assess qualitative olfactory function in health and disease.
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Parosmia is associated with relevant olfactory recovery after olfactory training
2020Co-Authors: David T. Liu, Antje Haehner, Carl Philpott, Maha Sabha, Michael Damm, Anna Oleszkiewicz, Thomas HummelAbstract:Objectives This study aims to determine the association between Parosmia and clinically relevant recovery in olfactory function in patients with smell loss receiving olfactory training. Design and setting This was a retrospective cohort study of patients that received olfactory training. Adult patients with the major complaint of quantitative smell loss were recruited and treated at several ENT clinics in German between 2008 and 2018. Participants A total of 243 participants were included. Main outcome measures Changes in olfactory function after olfactory training. Age, gender, baseline olfactory function, etiology and duration of smell loss, duration of training, and presence of Parosmia and phantosmia were assessed for their impact on clinically relevant changes in overall and subdimension olfactory function using binary logistic regression analysis. Results Relevant improvements in discrimination function were more likely in those that had lower baseline olfactory function, postinfectious reasons compared to posttraumatic or idiopathic causes and those that had Parosmia at initial visit. Relevant improvements in odour identification were more likely in those that had a lower baseline olfactory function, female gender, and in those who had Parosmia at the first visit. Clinically significant improvements in odour threshold were more likely in postinfectious causes compared to posttraumatic reasons and those who were older in age. Conclusions This study demonstrated that the presence of Parosmia is associated with clinically relevant recovery in olfactory function in patients with smell loss receiving olfactory training.
Svetlana Kopishinskaia - One of the best experts on this subject based on the ideXlab platform.
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clinical features in russian patients with covid associated Parosmia phanthosmia
Psychiatria Danubina, 2021Co-Authors: Svetlana Kopishinskaia, Daria Lapshova, Mikhail Sherman, Ivan Velichko, Nikolai Voznesensky, Vera VoznesenskaiaAbstract:Background Olfactory dysfunction is a typical symptom of COVID-19 infection. While COVID-associated anosmia is well-described, knowledge of Parosmia (olfactory distortions) and phanthosmia (olfactory hallucinations) is relatively lacking. We undertook a clinical study of the Parosmia/phanthosmia phenotype, aiming to support improved prediction and management of these symptoms. Subjects and methods In a cross-sectional study between September 2020 and May 2021, we recruited 187 COVID-19 patients with Parosmia/phanthosmia via social media and a matched healthy control group from neurologists. The patients received an online video-consultation with a neurologist trained in olfactory research and completed a questionnaire to assess the nature of their subjective olfactory disorder. Results In the acute period of COVID-19 Parosmia/phanthosmia, patients often experienced comorbid manifestations such as fatigue, fever, headache, myalgia, and "brain fog". Isolated phanthosmia was observed in 13.9% of acute COVID-19 patients, as compared to 34.2% in the long term. Parosmia was described in 89.8% of patients in the long-term course of the disease. COVID-associated Parosmia/phanthosmia was more common in women (81.3%) than men (18.7%). Almost all Parosmia/phanthosmia patients had an acute history of anosmia, which often progressed to hyposmia. A third of the patients had a history of taste disturbance The long-term COVID-19 sequelae such as fatigue, brain fog, and dizziness are significantly more common among patients with Parosmia/phanthosmia, as were autonomic symptoms such as awareness of heartbeat and rapid pulse. The incidence of migraine with aura was significantly higher in the Parosmia/phanthosmia group than in the control group (8% versus 0.9%). The allergy was reported significantly more frequent in the study group compared to the control group. Conclusions Qualitative olfactory disorders occur frequently in COVID-19 patients. Those with the Parosmia/phanthosmia phenotype have a higher risk for other symptoms, notably headache (including migraine with aura), fatigue, brain fog, dizziness, and cardiovascular/autonomic manifestations, as well as allergy. We suppose that further investigation of this phenomenon will reveal phenotypic variants depending on particular symptoms cluster; improved nosology of qualitative olfactory disorders in COIVD-19 is a prerequisite for establishing appropriate treatments.
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clinical features in patients with covid associated Parosmia phanthosmia
European Journal of Neurology, 2021Co-Authors: E Goldberg, Mikhail Sherman, O Efankina, Svetlana KopishinskaiaAbstract:Background and aims: The purpose of the study is to identify clinical signs in patients with COVID-associated Parosmia / phanthosmia. Methods: The study group consisted of 185 patients 18 years old with COVID-associated Parosmia / phanthosmia. SARS-CoV-2 was laboratory confirmed in all patients. The patients were taken from the Telegram group and were interviewed by a doctor after signing an informed consent. Results: There are 28% of men and 78% of women in the study group. Parosmia was observed in 93% of patients, phanthosmia - 42%, anosmia - 20%, hyposmia - 48%, hyperosmia - 5%. Almost all patients had a history of anosmia (98%). The onset of COVID-associated Parosmia is often gradual, while in phanthosmia it is acute. One third of patients had a history of taste disturbance. The comorbid symptoms are increased fatigue - 100%, head fog- 55%, sleep disturbances - 46%, recurrent nasal congestion - 25%, burning in the nose - 20%, dryness in the nose - 18%. More than half of the patients have cardiovascular complaints. Most patients have a history of headache, and 69% have migraine. Half of the patients have a history of allergic diseases. Conclusion: COVID-associated Parosmia / phanthosmia is more common in women - gender factor is not excluded. A combination of olfactory disturbances among themselves was more often observed, in almost all Parosmia. All patients had persistent comorbid symptoms. Most of the patients had a history of migraine. Prophylactic anti-migraine therapy can be offered to patients with COVID-associated Parosmia / phanthosmia.