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Jameie M, Ahli B, Ghadir S, Azami M, Amanollahi M, Ebadi R, Rafati A, Naser Moghadasi A. The hidden link: How oral and respiratory microbiomes affect multiple sclerosis. Mult Scler Relat Disord 2024; 88:105742. [PMID: 38964239 DOI: 10.1016/j.msard.2024.105742] [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: 04/28/2024] [Revised: 06/16/2024] [Accepted: 06/20/2024] [Indexed: 07/06/2024]
Abstract
BACKGROUND Extensive research has explored the role of gut microbiota in multiple sclerosis (MS). However, the impact of microbial communities in the oral cavity and respiratory tract on MS is an emerging area of investigation. PURPOSE We aimed to review the current literature related to the nasal, oral, and lung microbiota in people with MS (PwMS). METHODS We conducted a narrative review of clinical and preclinical original studies on PubMed that explored the relationship between the bacterial or viral composition of the nasal, lung, and oral microbiota and MS. Additionally, to find relevant studies not retrieved initially, we also searched for references in related review papers, as well as the references cited within the included studies. RESULTS AND CONCLUSIONS Thirteen studies were meticulously reviewed in three sections; oral microbiota (n = 8), nasal microbiota (n = 3), and lung microbiota (n = 2), highlighting considerable alterations in the oral and respiratory microbiome of PwMS compared to healthy controls (HCs). Genera like Aggregatibacter and Streptococcus were less abundant in the oral microbiota of PwMS compared to HCs, while Staphylococcus, Leptotrichia, Fusobacterium, and Bacteroides showed increased abundance in PwMS. Additionally, the presence of specific bacteria, including Streptococcus sanguinis, within the oral microbiota was suggested to influence Epstein-Barr virus reactivation, a well-established risk factor for MS. Studies related to the nasal microbiome indicated elevated levels of specific Staphylococcus aureus toxins, as well as nasal glial cell infection with human herpes virus (HHV)-6 in PwMS. Emerging research on lung microbiome in animal models demonstrated that manipulating the lung microbiome towards lipopolysaccharide-producing bacteria might suppress MS symptoms. These findings open avenues for potential therapeutic strategies. However, further research is crucial to fully understand the complex interactions between the microbiome and MS. This will help identify the most effective timing, bacterial strains, and modulation techniques.
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Affiliation(s)
- Melika Jameie
- Neuroscience Research Center, Iran University of Medical Sciences, Tehran, Iran; Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Bahareh Ahli
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Sara Ghadir
- Student Research Committee, Babol University of Medical Sciences, Babol, Iran
| | - Mobin Azami
- Student Research Committee, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Mobina Amanollahi
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Ebadi
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Rafati
- School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Abdorreza Naser Moghadasi
- Multiple Sclerosis Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran.
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Stekic A, Dragic M, Stanojevic J, Zaric Kontic M, Stevanovic I, Zeljkovic Jovanovic M, Mihajlovic K, Nedeljkovic N. Impaired olfactory performance and anxiety-like behavior in a rat model of multiple sclerosis are associated with enhanced adenosine signaling in the olfactory bulb via A 1R, A 2BR, and A 3R. Front Cell Neurosci 2024; 18:1407975. [PMID: 39139401 PMCID: PMC11320153 DOI: 10.3389/fncel.2024.1407975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 07/02/2024] [Indexed: 08/15/2024] Open
Abstract
The present study shows that animals with experimental autoimmune encephalomyelitis (EAE) exhibit olfactory dysfunction and impaired general cognitive abilities, as well as anxiety-like behavior. Olfactory dysfunction occurs on average at 2 dpi, well before the onset of the first motor signs of EAE (8-10 dpi). After the initial olfactory dysfunction, the EAE animals show a fluctuation in olfactory performance that resembles the relapsing-remitting course of human MS. The study also shows severe neuroinflammation in the olfactory bulb (OB), with numerous infiltrated CD4+ T cells and peripheral macrophages in the superficial OB layers, marked microgliosis, and massive induction of TNF-α, IL-1β, and IL-6. Reduced tyrosine hydroxylase activity in the glomerular layer, pronounced granule cell atrophy, and reduced numbers of type B neuroblasts in the rostral migratory stream also indicate altered plasticity of the neuronal network in the OB. Considering the exceptionally high purinome expression in the OB, the possible involvement of purinergic signaling was also investigated. The study shows that macrophages infiltrating the OB overexpress A3R, while highly reactive microglia overexpress the adenosine-producing enzyme eN/CD73 as well as A2BR, A3R, and P2X4R. Given the simultaneous induction of complement component C3, the results suggest that the microglial cells develop a functional phenotype of phagocytizing microglia. The study also demonstrates transcriptional and translational upregulation of A1R in mitral and tufted cells, which likely influence resting network activity in OB and likely contribute to olfactory dysfunction in EAE. Overall, our study shows that olfactory dysfunction and altered social and cognitive behavior in EAE are associated with increased adenosine signaling via A1R, A2BR, and A3R.
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Affiliation(s)
- Andjela Stekic
- Laboratory for Neurobiology, Department of General Physiology and Biophysics, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Milorad Dragic
- Laboratory for Neurobiology, Department of General Physiology and Biophysics, Faculty of Biology, University of Belgrade, Belgrade, Serbia
- Vinca Institute of Nuclear Sciences, Institute of National Significance, University of Belgrade, Belgrade, Serbia
| | - Jelena Stanojevic
- Medical Faculty of Military Medical Academy, University of Defense, Belgrade, Serbia
| | - Marina Zaric Kontic
- Department of Molecular Biology and Endocrinology, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Ivana Stevanovic
- Medical Faculty of Military Medical Academy, University of Defense, Belgrade, Serbia
| | - Milica Zeljkovic Jovanovic
- Laboratory for Neurobiology, Department of General Physiology and Biophysics, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Katarina Mihajlovic
- Laboratory for Neurobiology, Department of General Physiology and Biophysics, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Nadezda Nedeljkovic
- Laboratory for Neurobiology, Department of General Physiology and Biophysics, Faculty of Biology, University of Belgrade, Belgrade, Serbia
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Stark R. The olfactory bulb: A neuroendocrine spotlight on feeding and metabolism. J Neuroendocrinol 2024; 36:e13382. [PMID: 38468186 DOI: 10.1111/jne.13382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/22/2024] [Accepted: 02/25/2024] [Indexed: 03/13/2024]
Abstract
Olfaction is the most ancient sense and is needed for food-seeking, danger protection, mating and survival. It is often the first sensory modality to perceive changes in the external environment, before sight, taste or sound. Odour molecules activate olfactory sensory neurons that reside on the olfactory epithelium in the nasal cavity, which transmits this odour-specific information to the olfactory bulb (OB), where it is relayed to higher brain regions involved in olfactory perception and behaviour. Besides odour processing, recent studies suggest that the OB extends its function into the regulation of food intake and energy balance. Furthermore, numerous hormone receptors associated with appetite and metabolism are expressed within the OB, suggesting a neuroendocrine role outside the hypothalamus. Olfactory cues are important to promote food preparatory behaviours and consumption, such as enhancing appetite and salivation. In addition, altered metabolism or energy state (fasting, satiety and overnutrition) can change olfactory processing and perception. Similarly, various animal models and human pathologies indicate a strong link between olfactory impairment and metabolic dysfunction. Therefore, understanding the nature of this reciprocal relationship is critical to understand how olfactory or metabolic disorders arise. This present review elaborates on the connection between olfaction, feeding behaviour and metabolism and will shed light on the neuroendocrine role of the OB as an interface between the external and internal environments. Elucidating the specific mechanisms by which olfactory signals are integrated and translated into metabolic responses holds promise for the development of targeted therapeutic strategies and interventions aimed at modulating appetite and promoting metabolic health.
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Affiliation(s)
- Romana Stark
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia
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Iannucci V, Bruscolini A, Iannella G, Visioli G, Alisi L, Salducci M, Greco A, Lambiase A. Olfactory Dysfunction and Glaucoma. Biomedicines 2024; 12:1002. [PMID: 38790964 PMCID: PMC11117544 DOI: 10.3390/biomedicines12051002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/27/2024] [Accepted: 04/29/2024] [Indexed: 05/26/2024] Open
Abstract
BACKGROUND Olfactory dysfunction is a well-known phenomenon in neurological diseases with anosmia and hyposmia serving as clinical or preclinical indicators of Alzheimer's disease, Parkinson's disease, and other neurodegenerative disorders. Since glaucoma is a neurodegenerative disease of the visual system, it may also entail alterations in olfactory function, warranting investigation into potential sensory interconnections. METHODS A review of the current literature of the last 15 years (from 1 April 2008 to 1 April 2023) was conducted by two different authors searching for topics related to olfaction and glaucoma. RESULTS three papers met the selection criteria. According to these findings, patients with POAG appear to have worse olfaction than healthy subjects. Furthermore, certain predisposing conditions to glaucoma, such as pseudoexfoliation syndrome and primary vascular dysregulation, could possibly induce olfactory changes that can be measured with the Sniffin Stick test. CONCLUSIONS the scientific literature on this topic is very limited, and the pathogenesis of olfactory changes in glaucoma is not clear. However, if the results of these studies are confirmed by further research, olfactory testing may be a non-invasive tool to assist clinicians in the early diagnosis of glaucoma.
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Affiliation(s)
| | | | | | | | | | | | | | - Alessandro Lambiase
- Department of Sense Organs, Sapienza University of Rome, Viale del Policlinico 155, 00161 Rome, Italy; (V.I.); (A.B.); (G.I.); (G.V.); (L.A.); (M.S.); (A.G.)
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Weerasinghe-Mudiyanselage PDE, Kim JS, Shin T, Moon C. Understanding the spectrum of non-motor symptoms in multiple sclerosis: insights from animal models. Neural Regen Res 2024; 19:84-91. [PMID: 37488849 PMCID: PMC10479859 DOI: 10.4103/1673-5374.375307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/12/2023] [Accepted: 04/17/2023] [Indexed: 07/26/2023] Open
Abstract
Multiple sclerosis is a chronic autoimmune disease of the central nervous system and is generally considered to be a non-traumatic, physically debilitating neurological disorder. In addition to experiencing motor disability, patients with multiple sclerosis also experience a variety of non-motor symptoms, including cognitive deficits, anxiety, depression, sensory impairments, and pain. However, the pathogenesis and treatment of such non-motor symptoms in multiple sclerosis are still under research. Preclinical studies for multiple sclerosis benefit from the use of disease-appropriate animal models, including experimental autoimmune encephalomyelitis. Prior to understanding the pathophysiology and developing treatments for non-motor symptoms, it is critical to characterize the animal model in terms of its ability to replicate certain non-motor features of multiple sclerosis. As such, no single animal model can mimic the entire spectrum of symptoms. This review focuses on the non-motor symptoms that have been investigated in animal models of multiple sclerosis as well as possible underlying mechanisms. Further, we highlighted gaps in the literature to explain the non-motor aspects of multiple sclerosis in experimental animal models, which will serve as the basis for future studies.
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Affiliation(s)
- Poornima D. E. Weerasinghe-Mudiyanselage
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR program, Chonnam National University, Gwangju, Republic of Korea
| | - Joong-Sun Kim
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR program, Chonnam National University, Gwangju, Republic of Korea
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju, Republic of Korea
| | - Changjong Moon
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR program, Chonnam National University, Gwangju, Republic of Korea
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Piura Y, Karni A, Kolb H, Vigiser I, Regev K. Olfactory function in Susac syndrome. Clin Neurol Neurosurg 2023; 233:107909. [PMID: 37524045 DOI: 10.1016/j.clineuro.2023.107909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/12/2023] [Accepted: 07/17/2023] [Indexed: 08/02/2023]
Abstract
OBJECTIVES Susac syndrome is a rare autoimmune endotheliopathy involving the brain, retina, and inner ear. Olfactory dysfunction is a common early manifestation of several central nervous system diseases, including neurodegenerative diseases and autoimmune-mediated diseases such as Multiple Sclerosis. While the literature is abundant about the Susac syndrome classic triad of encephalopathy, branch retinal artery occlusion, and low-frequency sensorineural hearing loss, little is known about the extent of olfactory sense involvement. METHODS Using the Sniffin' Sticks test, this study evaluated olfactory function (identification and threshold) in ten recovering Susac syndrome patients under our clinic surveillance with a median of 3.1 (SD=1.53) years post-disease onset. RESULTS olfactory assessment by threshold and odor identification were within the normal range. No differences between recovering Susac syndrome patients to standard norms of odor identification and threshold were found. CONCLUSIONS Our findings do not support olfactory dysfunction in Susac syndrome and thereby, do not support olfactory assessment as a reliable biomarker for this condition.
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Affiliation(s)
- Yoav Piura
- Department of Neurology, Assuta Medical Center, Ashdod, Israel; Neuroimmunology Clinic, Assuta Medical Center, Ashdod, Israel.
| | - Arnon Karni
- Department of Neurology, Sourasky Tel Aviv Medical Center, Tel Aviv, Israel; Neuroimmunology Unit, Neurological Institute Aviv Medical Center, Tel Aviv, Israel
| | - Hadar Kolb
- Department of Neurology, Sourasky Tel Aviv Medical Center, Tel Aviv, Israel; Neuroimmunology Unit, Neurological Institute Aviv Medical Center, Tel Aviv, Israel
| | - Ifat Vigiser
- Department of Neurology, Sourasky Tel Aviv Medical Center, Tel Aviv, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; Neuroimmunology Unit, Neurological Institute Aviv Medical Center, Tel Aviv, Israel
| | - Keren Regev
- Department of Neurology, Sourasky Tel Aviv Medical Center, Tel Aviv, Israel; Neuroimmunology Unit, Neurological Institute Aviv Medical Center, Tel Aviv, Israel
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Todd LL, Sivakumar R, Lynch SG, Diebolt JH, White J, Villwock JA. Longitudinal Olfactory Patterns in Multiple Sclerosis: A Scoping Review and Implication for Use in Management of Disease. Int J MS Care 2023; 25:131-136. [PMID: 37250191 PMCID: PMC10211351 DOI: 10.7224/1537-2073.2022-019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND Although studies regarding multiple sclerosis (MS) and olfactory dysfunction (OD) have been previously described and summarized, there is not a sole review of longitudinal studies regarding the matter. This review examines the existing literature investigating MS and its effect on olfaction. In addition, the role of OD in the diagnosis and prognosis of MS is explored. METHODS A scoping review of the literature was performed covering longitudinal studies investigating MS and OD. Systematic searches of PubMed, Google Scholar, Web of Science, Embase, PsycInfo, Cumulative Index to Nursing and Allied Health Literature, AgeLine, and MEDLINE were performed using terms that encompassed MS and olfaction. The aim of this review was to build on the existing literature by summarizing only findings that were demonstrated longitudinally. RESULTS Of 6938 articles identified from the search, 9 met the inclusion criteria: longitudinal observation of relapsing-remitting or progressive MS. Olfaction was measured and scored using various testing arrays, and these scores were then correlated with a multitude of clinical markers. Across all studies, patients with MS demonstrated increased OD. Longitudinally, 2 contrasting patterns were identified: (1) clinical markers of acute inflammation correlated with an increased odor threshold and (2) clinical markers of neurodegeneration, or progression of disease, correlated with a decreased ability to discriminate and identify odors. CONCLUSIONS These studies suggest that olfaction is a dynamic, dependent variable of neurodegeneration, correlating with inflammation and clinical markers. This opens the door for future exploration of olfaction's relationship with MS diagnosis, characterization, and therapeutic response.
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Affiliation(s)
- Lauren L. Todd
- From the School of Medicine (LLT, RS), University of Kansas Medical Center, Kansas City, KS, USA
| | - Ram Sivakumar
- From the School of Medicine (LLT, RS), University of Kansas Medical Center, Kansas City, KS, USA
| | - Sharon G. Lynch
- From the Department of Neurology (SGL), University of Kansas Medical Center, Kansas City, KS, USA
| | - Jennifer H. Diebolt
- From the Department of Otolaryngology (JHD, JAV), University of Kansas Medical Center, Kansas City, KS, USA
| | - Jacob White
- Welch Medical Library, Johns Hopkins University, Baltimore, MD, USA (JW)
| | - Jennifer A. Villwock
- From the Department of Otolaryngology (JHD, JAV), University of Kansas Medical Center, Kansas City, KS, USA
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Acikgoz M, Piri Cinar B, Aciman Demirel E, Celebi U, Cekic S, Elicora S, Atasoy HT. The effects of cognition, quality of life, and fatigue on olfactory function in patients with multiple sclerosis. Clin Neurol Neurosurg 2023; 229:107739. [PMID: 37146370 DOI: 10.1016/j.clineuro.2023.107739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/18/2023] [Accepted: 04/20/2023] [Indexed: 05/07/2023]
Abstract
AIM The frequency of olfactory dysfunction in patients with Multiple Sclerosis (MS) has revealed very different results in studies. Some studies have shown that olfactory dysfunction may be associated with cognitive impairment and poor quality of life. In these studies, different odor tests and cognitive tests were used and different results were obtained. MATERIALS AND METHODS Forty literate patients over the age of 18 and 24 healthy volunteers of similar age and education were included in the study. Sniffin' Sticks Odor Test, California Verbal Learning Test II, Symbol Digit Modalities Test, Revised Brief Visuospatial Memory Test, Trail-Making Test, Quality of Life Short Form-36, Fatigue Impact Scale, Beck Depression Inventory, and Beck Anxiety Inventory were applied to the individuals. RESULTS Olfactory dysfunction was detected in 50 % of the patients. High disability rate, low cognitive functions, low quality of life, and fatigue were identified as the factors affecting olfactory function negatively. Odor discrimination and identification abilities were associated with disability level and cognitive functions, whereas quality of life was linked to odor threshold scores. The olfactory function and cognitive abilities of patients with progressive MS (n = 5) were worse than those of patients with relapsing remitting MS (n = 35). CONCLUSION Olfactory dysfunction is common in patients with MS and is associated with disability and quality of life. Olfactory function can be used in the follow-up of patients and olfactory dysfunction deserves further study as a metric that might emerge as a biomarker.
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Affiliation(s)
- Mustafa Acikgoz
- Department of Neurology, Faculty of Medicine, Zonguldak Bulent Ecevit University, Zonguldak, Turkey.
| | - Bilge Piri Cinar
- Department of Neurology, Faculty of Medicine, Zonguldak Bulent Ecevit University, Zonguldak, Turkey
| | - Esra Aciman Demirel
- Department of Neurology, Faculty of Medicine, Zonguldak Bulent Ecevit University, Zonguldak, Turkey
| | - Ulufer Celebi
- Department of Neurology, Faculty of Medicine, Zonguldak Bulent Ecevit University, Zonguldak, Turkey
| | - Sibel Cekic
- Department of Neurology, Bursa Dr. Ayten Bozkaya Spastic Children's Hospital and Rehabilitation Center, Bursa, Turkey
| | - Sultan Elicora
- Department of Otorhinolaryngology, Kocaeli Health and Technology University, Kocaeli, Turkey
| | - Hüseyin Tugrul Atasoy
- Department of Neurology, Faculty of Medicine, Zonguldak Bulent Ecevit University, Zonguldak, Turkey
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Santos M, Geraldes R, Palace J. Olfactory threshold as a biomarker of disease activity. Mult Scler 2022; 29:762-763. [PMID: 36131527 DOI: 10.1177/13524585221122239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Mónica Santos
- Neurology, Department of Neurosciences and Mental Health, Hospital de Santa Maria/Centro Hospitalar Lisboa Norte, Lisbon, Portugal.,Clinical Neurology, John Radcliffe Hospital, Oxford University Foundation Trust, Oxford, UK
| | - Ruth Geraldes
- Clinical Neurology, John Radcliffe Hospital, Oxford University Foundation Trust, Oxford, UK.,Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Jacqueline Palace
- Clinical Neurology, John Radcliffe Hospital, Oxford University Foundation Trust, Oxford, UK.,Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
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Printza A, Boziki M, Valsamidis C, Bakirtzis C, Constantinidis J, Grigoriadis N, Triaridis S. Smell as a Disease Marker in Multiple Sclerosis. J Clin Med 2022; 11:jcm11175215. [PMID: 36079145 PMCID: PMC9457284 DOI: 10.3390/jcm11175215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/24/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Existing data suggest that people with multiple sclerosis (pwMS) are at an elevated risk for experiencing olfactory impairment. We investigated if smell dysfunction can be used as an MS disease marker. This is a cross-sectional, case−control study. All data were collected prospectively from 171 participants, 115 pwMS and 56 controls (age and sex stratified and matched to the patients), who reported smell, taste, and nasal breathing, and completed the Greek-validated questionnaires for nasal obstruction (NOSE), nasal-symptoms QoL (SNOT-22), and olfaction-associated QoL (QOD). The smell was assessed with the “Sniffin’ sticks” (odor threshold (OT), discrimination (OD), identification (OI) test, and total TDI). We recorded the pwMS disease characteristics (Expanded Disability Status Scale-EDSS, the disease type and duration), cognitive function, emotional status, fatigue, and impact of MS in everyday activities. A TDI < 30.75 (hyposmia) was detected in 30.8% of the patients. The patients’ OD and TDI scores were significantly lower than the controls’ (p = 0.005, and 0.015, respectively). The hyposmia correlated with disease severity and duration. The EDSS score correlated negatively with OD (r = −0.299, p = 0.001) and TDI (r = −0.242, p = 0.01). The disease duration correlated negatively with OD (r = −0.305, p = 0.001, OI (r = −0.253, p = 0.008) and TDI (r = −0.3, p = 0.001). The information processing speed (SDMT) correlated with OD, OT, and TDI (r = 0.302, p = 0.002; r = 0.242, p = 0.016; r = 0.326, p = 0.001). The olfactory function is changing in MS in accordance with disease progression.
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Affiliation(s)
- Athanasia Printza
- 1st Otolaryngology Department, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, AHEPA Hospital, 54124 Thessaloniki, Greece
- Correspondence:
| | - Marina Boziki
- 2nd Neurology Department, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, AHEPA Hospital, 54124 Thessaloniki, Greece
| | - Constantinos Valsamidis
- 1st Otolaryngology Department, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, AHEPA Hospital, 54124 Thessaloniki, Greece
| | - Christos Bakirtzis
- 2nd Neurology Department, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, AHEPA Hospital, 54124 Thessaloniki, Greece
| | - Jannis Constantinidis
- 1st Otolaryngology Department, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, AHEPA Hospital, 54124 Thessaloniki, Greece
| | - Nikolaos Grigoriadis
- 2nd Neurology Department, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, AHEPA Hospital, 54124 Thessaloniki, Greece
| | - Stefanos Triaridis
- 1st Otolaryngology Department, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, AHEPA Hospital, 54124 Thessaloniki, Greece
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