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Abstract
Historically, the human sense of smell has been regarded as the odd stepchild of the senses, especially compared to the sensory bravado of seeing, touching, and hearing. The idea that the human olfaction has little to contribute to our experience of the world is commonplace, though with the emergence of COVID-19 there has rather been a sea change in this understanding. An ever increasing body of work has convincingly highlighted the keen capabilities of the human nose and the sophistication of the human olfactory system. Here, we provide a concise overview of the neuroscience of human olfaction spanning the last 10-15 years, with focus on the peripheral and central mechanisms that underlie how odor information is processed, packaged, parceled, predicted, and perturbed to serve odor-guided behaviors. We conclude by offering some guideposts for harnessing the next decade of olfactory research in all its shapes and forms.
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Affiliation(s)
| | - Jay A Gottfried
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA; ,
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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2
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Licht T, Yunerman M, Maor I, Lawabny N, Oz Rokach R, Shiff I, Mizrahi A, Rokni D. Adaptive olfactory circuitry restores function despite severe olfactory bulb degeneration. Curr Biol 2023; 33:4857-4868.e6. [PMID: 37858342 PMCID: PMC10681124 DOI: 10.1016/j.cub.2023.09.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 08/31/2023] [Accepted: 09/25/2023] [Indexed: 10/21/2023]
Abstract
The olfactory bulb (OB) is a critical component of mammalian olfactory neuroanatomy. Beyond being the first and sole relay station for olfactory information to the rest of the brain, it also contains elaborate stereotypical circuitry that is considered essential for olfaction. Indeed, substantial lesions of the OB in rodents lead to anosmia. Here, we examined the circuitry that underlies olfaction in a mouse model with severe developmental degeneration of the OB. These mice could perform odor-guided tasks and even responded normally to innate olfactory cues. Despite the near total loss of the OB, piriform cortices in these mice responded to odors, and its neural activity sufficed to decode odor identity. We found that sensory neurons express the full repertoire of olfactory receptors, and their axons project primarily to the rudiments of the OB but also, ectopically, to olfactory cortical regions. Within the OB, the number of principal neurons was greatly reduced, and the morphology of their dendrites was abnormal, extending over large regions within the OB. Glomerular organization was totally lost in the severe cases of OB degeneration and altered in the more conserved OBs. This study shows that olfactory functionality can be preserved despite reduced and aberrant circuitry that is missing many of the elements believed to be essential for olfaction, and it may explain reported retention of olfaction in humans with degenerated OBs.
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Affiliation(s)
- Tamar Licht
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel.
| | - Michael Yunerman
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel
| | - Ido Maor
- Department of Neurobiology, The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Naheel Lawabny
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel
| | - Renana Oz Rokach
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel
| | - Idit Shiff
- Genomics Applications Laboratory, Core Research Facility, Faculty of Medicine, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel
| | - Adi Mizrahi
- Department of Neurobiology, The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Dan Rokni
- Department of Medical Neurobiology, Faculty of Medicine and IMRIC, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel.
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Yan X, Benkhatar H, Chao YT, Georgiopoulos C, Hummel T. Anterior Skull Base Abnormalities in Congenital Anosmia. ORL J Otorhinolaryngol Relat Spec 2023; 86:1-12. [PMID: 37607521 DOI: 10.1159/000532077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/11/2023] [Indexed: 08/24/2023]
Abstract
INTRODUCTION The structures of the skull and the brain are related to each other. Prior work in individuals with isolated congenital anosmia (ICA) showed that these individuals were characterized by olfactory bulb (OB) defects. The aim of this study was to compare the morphological pattern of the anterior skull base surrounding the OB between individuals with ICA and normosmic controls. We meant to investigate whether these features can help distinguish abnormalities from normal variation. METHODS We conducted a retrospective study to acquire T2-weighted magnetic resonance images from individuals diagnosed with ICA (n = 31) and healthy, normosmic controls matched for age and gender (n = 62). Between both groups, we compared the depth and width of the olfactory fossa, the angle of the ethmoidal fovea, as well as the angle of the lateral lamella of the cribriform plate. Within the ICA group, we further performed subgroup analyses based on the presence or absence of the OB, to investigate whether the morphology of the anterior skull base relates to the presence of OBs. The diagnostic performance of these parameters was evaluated using receiver operating characteristic analysis. RESULTS Individuals with ICA exhibited a flattened ethmoid roof and shallower olfactory fossa when compared to controls. Further, the absence of the OB was found to be associated with a higher degree of flattening of the ethmoid roof and a shallow olfactory fossa. We reached the results in the following areas under the receiver operating characteristic curves: 0.80 - angle of fovea ethmoidalis, 0.76 - depth of olfactory fossa, 0.70 - angle of lateral lamella of the cribriform plate for significant differentiation between individuals with ICA and normosmic controls. CONCLUSION Individuals with ICA exhibited an unusual anterior skull base surrounding the OB. This study supports the idea of an integrated development of OB and anterior skull base. Hence, the morphological pattern of the anterior skull base surrounding the OB helps distinguish individuals with ICA from normosmic controls and may therefore be useful for the diagnosis of ICA, although it is certainly not an invariable sign of congenital anosmia.
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Affiliation(s)
- Xiaoguang Yan
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Hakim Benkhatar
- Department of ENT and Head and Neck Surgery, Versailles Hospital, Le Chesnay-Rocquencourt, France
| | - Yun-Ting Chao
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
- Division of Rhinology, Department of Otorhinolaryngology-Head and Neck Surgery, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Brain Science, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Charalampos Georgiopoulos
- Department of Radiology and Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
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Hummel T, Power Guerra N, Gunder N, Hähner A, Menzel S. Olfactory Function and Olfactory Disorders. Laryngorhinootologie 2023; 102:S67-S92. [PMID: 37130532 PMCID: PMC10184680 DOI: 10.1055/a-1957-3267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The sense of smell is important. This became especially clear to patients with infection-related olfactory loss during the SARS-CoV-2 pandemic. We react, for example, to the body odors of other humans. The sense of smell warns us of danger, and it allows us to perceive flavors when eating and drinking. In essence, this means quality of life. Therefore, anosmia must be taken seriously. Although olfactory receptor neurons are characterized by regenerative capacity, anosmia is relatively common with about 5 % of anosmic people in the general population. Olfactory disorders are classified according to their causes (e. g., infections of the upper respiratory tract, traumatic brain injury, chronic rhinosinusitis, age) with the resulting different therapeutic options and prognoses. Thorough history taking is therefore important. A wide variety of tools are available for diagnosis, ranging from short screening tests and detailed multidimensional test procedures to electrophysiological and imaging methods. Thus, quantitative olfactory disorders are easily assessable and traceable. For qualitative olfactory disorders such as parosmia, however, no objectifying diagnostic procedures are currently available. Therapeutic options for olfactory disorders are limited. Nevertheless, there are effective options consisting of olfactory training as well as various additive drug therapies. The consultation and the competent discussion with the patients are of major importance.
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Affiliation(s)
- T Hummel
- Interdisziplinäres Zentrum Riechen und Schmecken, HNO Klinik, TU Dresden
| | - N Power Guerra
- Rudolf-Zenker-Institut für Experimentelle Chirurgie, Medizinische Universität Rostock, Rostock
| | - N Gunder
- Universitäts-HNO Klinik Dresden, Dresden
| | - A Hähner
- Interdisziplinäres Zentrum Riechen und Schmecken, HNO Klinik, TU Dresden
| | - S Menzel
- Interdisziplinäres Zentrum Riechen und Schmecken, HNO Klinik, TU Dresden
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Carnemolla S, Kumfor F, Liang CT, Foxe D, Ahmed R, Piguet O. Olfactory Bulb Integrity in Frontotemporal Dementia and Alzheimer’s Disease. J Alzheimers Dis 2022; 89:51-66. [DOI: 10.3233/jad-220080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Olfactory dysfunction is highly prevalent in dementia syndromes, including Alzheimer’s disease (AD) and frontotemporal dementia (FTD). The structural integrity of the olfactory bulb (OB) is thought to play a critical role in odor detection and identification, but no MRI study has measured OB volume in FTD, or measured OB volume longitudinally in AD. Objective: To measure OB volume in FTD and AD patients longitudinally using MRI. Methods: This study measured OB volumes using MRI in patients diagnosed with behavioral-variant FTD (n = 55), semantic dementia (n = 34), progressive non-fluent aphasia (n = 30), AD (n = 50), and healthy age-matched controls (n = 55) at their first visit to a dementia research clinic (‘baseline’). Imaging data in patients 12-months later were analyzed where available (n = 84) for longitudinal assessment. Volumes of subcortical and cortical olfactory regions (‘olfactory network’) were obtained via surface-based morphometry. Results: Results revealed that in AD and FTD at baseline, OB volumes were similar to controls, whereas volumes of olfactory network regions were significantly reduced in all patient groups except in progressive non-fluent aphasia. Longitudinal data revealed that OB volume became significantly reduced (10–25% volume reduction) in all dementia groups with disease progression. Conclusion: Olfactory dysfunction is common in patients diagnosed with AD or FTD, but our results indicate that there is no detectable volume loss to the OBs upon first presentation to the clinic. Our findings indicate that the OBs become detectably atrophied later in the disease process. OB atrophy indicates the potential usefulness for OBs to be targeted in interventions to improve olfactory function.
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Affiliation(s)
- Sarah Carnemolla
- University of Sydney, School of Psychology, Sydney, New South Wales, Australia
- University of Sydney, Brain & Mind Centre, Sydney, New South Wales, Australia
| | - Fiona Kumfor
- University of Sydney, School of Psychology, Sydney, New South Wales, Australia
- University of Sydney, Brain & Mind Centre, Sydney, New South Wales, Australia
| | - Cheng Tao Liang
- University of Sydney, School of Psychology, Sydney, New South Wales, Australia
- University of Sydney, Brain & Mind Centre, Sydney, New South Wales, Australia
| | - David Foxe
- University of Sydney, School of Psychology, Sydney, New South Wales, Australia
- University of Sydney, Brain & Mind Centre, Sydney, New South Wales, Australia
| | - Rebekah Ahmed
- University of Sydney, Brain & Mind Centre, Sydney, New South Wales, Australia
- Memory and Cognition Clinic, Department of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
- University of Sydney, Central Sydney Medical School, Sydney, New South Wales, Australia
| | - Olivier Piguet
- University of Sydney, School of Psychology, Sydney, New South Wales, Australia
- University of Sydney, Brain & Mind Centre, Sydney, New South Wales, Australia
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Pellegrino R, Mignot C, Georgiopoulos C, Haehner A, Hummel T. Consequences of gaining olfactory function after lifelong anosmia. Neurocase 2021; 27:238-242. [PMID: 34003718 DOI: 10.1080/13554794.2021.1921221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
We present a rare case in which a patient has gained her smell after lifelong anosmia. The patient was objectively tested and diagnosed with functional anosmia at age 13 and reported they were experiencing a new sensation of smell at age 22. Our results show an electrophysiological signal for two unimodal odorants. The patient had a retronasal score in the hyposmic range and self-reported the ability to smell non-trigeminal odors, but reported being disturbed by the presence of the new sense and co-occurrence of phantosmia. We discuss our case in routes of neurogenesis and non-forming memory association with odors.
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Affiliation(s)
- Robert Pellegrino
- Department of Otorhinolaryngology, Smell & Taste Clinic, University of Dresden Medical School, Dresden, Germany
| | - Coralie Mignot
- Department of Otorhinolaryngology, Smell & Taste Clinic, University of Dresden Medical School, Dresden, Germany
| | - Charalampos Georgiopoulos
- Department of Otorhinolaryngology, Smell & Taste Clinic, University of Dresden Medical School, Dresden, Germany
| | - Antje Haehner
- Department of Otorhinolaryngology, Smell & Taste Clinic, University of Dresden Medical School, Dresden, Germany
| | - Thomas Hummel
- Department of Otorhinolaryngology, Smell & Taste Clinic, University of Dresden Medical School, Dresden, Germany
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Lee JC, Nallani R, Cass L, Bhalla V, Chiu AG, Villwock JA. A Systematic Review of the Neuropathologic Findings of Post-Viral Olfactory Dysfunction: Implications and Novel Insight for the COVID-19 Pandemic. Am J Rhinol Allergy 2021; 35:323-333. [PMID: 32915650 PMCID: PMC10404900 DOI: 10.1177/1945892420957853] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Post-viral olfactory dysfunction is a common cause of both short- and long-term smell alteration. The coronavirus pandemic further highlights the importance of post-viral olfactory dysfunction. Currently, a comprehensive review of the neural mechanism underpinning post-viral olfactory dysfunction is lacking. OBJECTIVES To synthesize the existing primary literature related to olfactory dysfunction secondary to viral infection, detail the underlying pathophysiological mechanisms, highlight relevance for the current COVID-19 pandemic, and identify high impact areas of future research. METHODS PubMed and Embase were searched to identify studies reporting primary scientific data on post-viral olfactory dysfunction. Results were supplemented by manual searches. Studies were categorized into animal and human studies for final analysis and summary. RESULTS A total of 38 animal studies and 7 human studies met inclusion criteria and were analyzed. There was significant variability in study design, experimental model, and outcome measured. Viral effects on the olfactory system varies significantly based on viral substrain but generally include damage or alteration in components of the olfactory epithelium and/or the olfactory bulb. CONCLUSIONS The mechanism of post-viral olfactory dysfunction is highly complex, virus-dependent, and involves a combination of insults at multiple levels of the olfactory pathway. This will have important implications for future diagnostic and therapeutic developments for patients infected with COVID-19.
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Affiliation(s)
- Jason C. Lee
- Department of Otolaryngology—Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas
| | - Rohit Nallani
- Department of Otolaryngology—Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas
| | - Lauren Cass
- Department of Otolaryngology—Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas
| | - Vidur Bhalla
- Saint Luke’s Hospital of Kansas City, Kansas City, Missouri
| | - Alexander G. Chiu
- Department of Otolaryngology—Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas
| | - Jennifer A. Villwock
- Department of Otolaryngology—Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas
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Joshi A, Thaploo D, Yan X, Herrmann T, Khabour HA, Hummel T. A novel technique for olfactory bulb measurements. PLoS One 2020; 15:e0243941. [PMID: 33326498 PMCID: PMC7743925 DOI: 10.1371/journal.pone.0243941] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/30/2020] [Indexed: 02/07/2023] Open
Abstract
Background To introduce new ways to calculate OB volumes, checking their validity and comparing them to already established technique i.e. OB volumetric based on manual segmentation of OB boundaries. Methods Two approaches were used to calculate OB volumes (1) Manual Segmentation using planimetric manual contouring; (2) Box-frame method, calculating the parameters based on a box placed around the OB. Results We calculated OB volumes using both techniques and found comparable outcomes. High inter-observer reliability was found for volumes calculated by both observers. For manual segmentation, Cronbach’s alpha (α) was 0.91 and 0.93 for right and left OB volume, respectively, whereas for the box-frame method α was 0.94 and 0.90 for right and left OB, respectively. Conclusions The simple box-frame method of OB volume calculation appears reliable. Its results are comparable to an established technique.
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Affiliation(s)
- Akshita Joshi
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
- * E-mail:
| | - Divesh Thaploo
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Xiaoguang Yan
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Theresa Herrmann
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | | | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
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Weiss T, Soroka T, Gorodisky L, Shushan S, Snitz K, Weissgross R, Furman-Haran E, Dhollander T, Sobel N. Human Olfaction without Apparent Olfactory Bulbs. Neuron 2020; 105:35-45.e5. [PMID: 31706696 PMCID: PMC6953431 DOI: 10.1016/j.neuron.2019.10.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 07/16/2019] [Accepted: 10/01/2019] [Indexed: 12/12/2022]
Abstract
The olfactory bulbs (OBs) are the first site of odor representation in the mammalian brain, and their unique ultrastructure is considered a necessary substrate for spatiotemporal coding of smell. Given this, we were struck by the serendipitous observation at MRI of two otherwise healthy young left-handed women, yet with no apparent OBs. Standardized tests revealed normal odor awareness, detection, discrimination, identification, and representation. Functional MRI of these women's brains revealed that odorant-induced activity in piriform cortex, the primary OB target, was similar in its extent to that of intact controls. Finally, review of a public brain-MRI database with 1,113 participants (606 women) also tested for olfactory performance, uncovered olfaction without anatomically defined OBs in ∼0.6% of women and ∼4.25% of left-handed women. Thus, humans can perform the basic facets of olfaction without canonical OBs, implying extreme plasticity in the functional neuroanatomy of this sensory system.
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Affiliation(s)
- Tali Weiss
- The Azrieli National Institute for Human Brain Imaging and Research, Weizmann Institute of Science, Rehovot, Israel; Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.
| | - Timna Soroka
- The Azrieli National Institute for Human Brain Imaging and Research, Weizmann Institute of Science, Rehovot, Israel; Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Lior Gorodisky
- The Azrieli National Institute for Human Brain Imaging and Research, Weizmann Institute of Science, Rehovot, Israel; Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Sagit Shushan
- The Azrieli National Institute for Human Brain Imaging and Research, Weizmann Institute of Science, Rehovot, Israel; Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Kobi Snitz
- The Azrieli National Institute for Human Brain Imaging and Research, Weizmann Institute of Science, Rehovot, Israel; Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Reut Weissgross
- The Azrieli National Institute for Human Brain Imaging and Research, Weizmann Institute of Science, Rehovot, Israel; Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Edna Furman-Haran
- The Azrieli National Institute for Human Brain Imaging and Research, Weizmann Institute of Science, Rehovot, Israel
| | - Thijs Dhollander
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia; The Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Noam Sobel
- The Azrieli National Institute for Human Brain Imaging and Research, Weizmann Institute of Science, Rehovot, Israel; Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.
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Braun JJ, Noblet V, Kremer S, Molière S, Dollfus H, Marion V, Goetz N, Muller J, Riehm S. Value of MRI olfactory bulb evaluation in the assessment of olfactory dysfunction in Bardet-Biedl syndrome. Clin Genet 2016; 90:79-83. [PMID: 26586152 DOI: 10.1111/cge.12697] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 11/16/2015] [Accepted: 11/16/2015] [Indexed: 11/27/2022]
Abstract
Olfactory bulb (OB) volume evaluation by magnetic resonance imaging (MRI) has been demonstrated to be related to olfactory dysfunction in many different diseases. Olfactory dysfunction is often overlooked in Bardet-Biedl syndrome (BBS) patients and is rarely objectively evaluated by MRI. We present a series of 20 BBS patients with olfactory dysfunction. The OB was evaluated separately and blindly by two radiologists (SR and SM) with 3 Tesla MRI imaging comparatively to 12 normal control subjects by global visual evaluation and by quantitative measurement of OB volume. In the 12 control cases OB visual evaluation was considered as normal in all cases for radiologist (SR) and in 10 cases for radiologist (SM). In the 20 BBS patients, OB visual evaluation was considered as abnormal in 18 cases for SR and in all cases for SM. OB volumetric evaluation for SR and SM in BBS patients was able to provide significant correlation between BBS and olfactory dysfunction. This study indicates that OB volume evaluation by MRI imaging like structural MRI scan for gray matter modifications demonstrates that olfactory dysfunction in BBS patients is a constant and cardinal symptom integrated in a genetical syndrome with peripheral and central olfactory structure alterations.
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Affiliation(s)
- J J Braun
- Service ORL-CCF, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - V Noblet
- Laboratoire ICUBE, UMR CNRS 7357, Strasbourg, France
| | - S Kremer
- Laboratoire ICUBE, UMR CNRS 7357, Strasbourg, France.,Service de Radiologie 2, Hôpitaux Universitaires de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - S Molière
- Service de Radiologie 2, Hôpitaux Universitaires de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - H Dollfus
- Service de Génétique Médicale, centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Laboratoire de Génétique Médicale, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - V Marion
- Laboratoire de Génétique Médicale, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - N Goetz
- Service de Génétique Médicale, centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - J Muller
- Laboratoire de Génétique Médicale, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France.,Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - S Riehm
- Service de Radiologie 1, Hôpitaux Universitaires de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
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Evaluation of post-traumatic anosmia with MRI and chemosensory ERPs. Eur Arch Otorhinolaryngol 2014; 272:1945-53. [DOI: 10.1007/s00405-014-3278-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 06/13/2013] [Indexed: 10/24/2022]
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Hummel T, Smitka M, Puschmann S, Gerber JC, Schaal B, Buschhüter D. Correlation between olfactory bulb volume and olfactory function in children and adolescents. Exp Brain Res 2011; 214:285-91. [PMID: 21842188 DOI: 10.1007/s00221-011-2832-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 08/01/2011] [Indexed: 01/19/2023]
Abstract
The olfactory bulb (OB) is considered to be the most important relay station in odor processing. The present study aimed to investigate the volumetric development of the human bulb and the olfactory function during childhood and youth. Furthermore, the present study aimed to investigate a possible correlation between OB volume and specific olfactory functions including odor threshold, odor discrimination and odor identification. A total of 87 subjects (46 boys, 41 girls), aged 1-17 years (mean age 8 years), participated in this study. None of them reported olfactory dysfunction or had signs of a dysfunctional sense of smell. Whenever possible, participants received a volumetric scan of the brain and lateralized olfactory tests. Volumetric measurements of the right and left OB were taken by manual segmentation of the coronal slices through the OB. Significant correlations between OB volumes and olfactory function were observed. Both, OB volumes and olfactory function increased with age, although the correlation between structure and function was not mediated by the subjects' age. In conclusion, for the first time, the present study showed a correlation between OB volume and olfactory functions in children.
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Affiliation(s)
- T Hummel
- Department of Otorhinolaryngology, University of Dresden Medical School, Fetscherstrasse 74, 01307 Dresden, Germany.
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Sivam A, Jeswani S, Reder L, Wang J, DeTineo M, Taxy J, Baroody FM, Naclerio RM, Pinto JM. Olfactory Cleft Inflammation is Present in Seasonal Allergic Rhinitis and is Reduced with Intranasal Steroids. Am J Rhinol Allergy 2010; 24:286-90. [DOI: 10.2500/ajra.2010.24.3478] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Background Allergic rhinitis (AR) is commonly associated with olfactory loss, although the mechanism is not well studied. This study was designed to determine the effect of mometasone furoate (MF) on olfactory loss in seasonal AR (SAR) and study its effect on inflammation in the olfactory region. Methods We performed a randomized, double-blind, placebo-controlled, parallel clinical trial in 17 patients with SAR who had symptoms of impaired olfaction. Subjects received MF or placebo for 2 weeks during their allergy season. Before and after treatment, we measured nasal peak inspiratory flow (NPIF), chemosensory quality of life, and objective olfactory function (the University of Pennsylvania Smell Identification Test). Additionally, nasal cytology samples were obtained from each visit, and a unilateral endoscopic biopsy specimen of the olfactory epithelium was obtained at the end of the study and scored for inflammation. Results Treatment with MF was associated with improved nasal symptoms (p < 0.015), NPIF (p < 0.04), reduced nasal inflammation (p < 0.05), and chemosensory-specific quality of life (p < 0.03). Histological analysis of the olfactory region reveals fewer eosinophils in the MF group when compared with placebo (p < 0.012). We found no improvement in objective olfactory function (p > 0.05). Conclusion The use of MF in SAR is associated with reduced eosinophilic inflammation in the olfactory region and improved symptoms of AR. The presence of eosinophils in the olfactory area in SAR may indicate a direct, deleterious effect of inflammation on olfactory epithelium in this disease. In this study we show that inflammation in SAR can affect the olfactory cleft, implicating a direct role for allergic inflammation in smell loss. Treatment with intranasal steroids is associated with decreased inflammation in the olfactory region in humans. This treatment is also associated with improved olfactory quality of life.
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Affiliation(s)
- Anita Sivam
- Department of Surgery, Section of Otolaryngology–Head and Neck Surgery, Chicago, Illinois
| | - Seema Jeswani
- Department of Surgery, Section of Otolaryngology–Head and Neck Surgery, Chicago, Illinois
| | - Lindsay Reder
- Department of Surgery, Section of Otolaryngology–Head and Neck Surgery, Chicago, Illinois
| | - Jianghong Wang
- Department of Surgery, Section of Otolaryngology–Head and Neck Surgery, Chicago, Illinois
| | - Marcella DeTineo
- Department of Surgery, Section of Otolaryngology–Head and Neck Surgery, Chicago, Illinois
| | - Jerome Taxy
- Department of Pathology, The University of Chicago, Chicago, Illinois
| | - Fuad M. Baroody
- Department of Surgery, Section of Otolaryngology–Head and Neck Surgery, Chicago, Illinois
| | - Robert M. Naclerio
- Department of Surgery, Section of Otolaryngology–Head and Neck Surgery, Chicago, Illinois
| | - Jayant M. Pinto
- Department of Surgery, Section of Otolaryngology–Head and Neck Surgery, Chicago, Illinois
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Olfactory bulb volume and depth of olfactory sulcus in patients with idiopathic olfactory loss. Eur Arch Otorhinolaryngol 2010; 267:1551-6. [DOI: 10.1007/s00405-010-1230-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 03/02/2010] [Indexed: 01/19/2023]
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