1
|
A novel feature extraction method using chemosensory EEG for Parkinson's disease classification. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2022.104147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
2
|
Oleszkiewicz A, Pettke K, Olze H, Uecker FC, Hummel T. Effects of odors on posture. J SENS STUD 2022. [DOI: 10.1111/joss.12796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna Oleszkiewicz
- Smell and Taste Clinic, Department of Otorhinolaryngology TU Dresden Dresden Germany
- Institute of Psychology University of Wroclaw Wroclaw
| | - Karolina Pettke
- Department of Otorhinolaryngology, Head and Neck Surgery Charité‐Universitätsmedizin Berlin Berlin Germany
| | - Heidi Olze
- Department of Otorhinolaryngology, Head and Neck Surgery Charité‐Universitätsmedizin Berlin Berlin Germany
| | - Florian C. Uecker
- Department of Otorhinolaryngology, Head and Neck Surgery Charité‐Universitätsmedizin Berlin Berlin Germany
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology TU Dresden Dresden Germany
| |
Collapse
|
3
|
Alonso CCG, Silva FG, Costa LOP, Freitas SMSF. Smell tests can discriminate Parkinson's disease patients from healthy individuals: A meta-analysis. Clin Neurol Neurosurg 2021; 211:107024. [PMID: 34823156 DOI: 10.1016/j.clineuro.2021.107024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/20/2021] [Accepted: 11/03/2021] [Indexed: 01/01/2023]
Abstract
BACKGROUND Olfactory impairment is common in Parkinson's disease (PD). The authors aimed to identify the clinical tests used to assess olfactory function and examine their ability to distinguish PD with different disease duration from healthy individuals with physiological aging. METHODS Cross-sectional studies published until May 2020 that assessed the olfaction of individuals with PD using search terms related to PD, olfactory function, and assessment were searched on PubMed, PsycInfo, Cinahl, and Web of Science databases. RESULTS Twelve smell tests were identified from the reviewed studies (n = 125) that assessed 8776 individuals with PD. Data of 6593 individuals with PD and 8731 healthy individuals were included in the meta-analyses. Individuals with PD presented worse performance than healthy individuals, regardless of the smell test used. The University of Pennsylvania Smell Identification Test (UPSIT) was used by most studies (n = 2310 individuals with PD) and presented smaller heterogeneity. When the studies were subclassified according to the years of PD duration, there were no significant differences. CONCLUSION All smell tests were able to discriminate the olfactory function of PD from that of healthy individuals, although the UPSIT was widely used. The abnormal olfaction was not related to the disease duration. Systematic review protocol registration (PROSPERO/2020-CRD42020160878).
Collapse
Affiliation(s)
- Cintia C G Alonso
- Masters and Doctoral Programs in Physical Therapy, Universidade Cidade de São Paulo, São Paulo, Brazil
| | - Fernanda G Silva
- Masters and Doctoral Programs in Physical Therapy, Universidade Cidade de São Paulo, São Paulo, Brazil
| | - Leonardo O P Costa
- Masters and Doctoral Programs in Physical Therapy, Universidade Cidade de São Paulo, São Paulo, Brazil
| | - Sandra M S F Freitas
- Masters and Doctoral Programs in Physical Therapy, Universidade Cidade de São Paulo, São Paulo, Brazil.
| |
Collapse
|
4
|
Tremblay C, Iravani B, Aubry Lafontaine É, Steffener J, Fischmeister FPS, Lundström JN, Frasnelli J. Parkinson's Disease Affects Functional Connectivity within the Olfactory-Trigeminal Network. JOURNAL OF PARKINSONS DISEASE 2021; 10:1587-1600. [PMID: 32597818 DOI: 10.3233/jpd-202062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Olfactory dysfunction (OD) is a frequent symptom of Parkinson's disease (PD) that appears years prior to diagnosis. Previous studies suggest that PD-related OD is different from non-parkinsonian forms of olfactory dysfunction (NPOD) as PD patients maintain trigeminal sensitivity as opposed to patients with NPOD who typically exhibit reduced trigeminal sensitivity. We hypothesize the presence of a specific alteration of functional connectivity between trigeminal and olfactory processing areas in PD. OBJECTIVE We aimed to assess potential differences in functional connectivity within the chemosensory network in 15 PD patients and compared them to 15 NPOD patients, and to 15 controls. METHODS Functional MRI scanning session included resting-state and task-related scans where participants carried out an olfactory and a trigeminal task. We compared functional connectivity, using a seed-based correlation approach, and brain network modularity of the chemosensory network. RESULTS PD patients had impaired functional connectivity within the chemosensory network while no such changes were observed for NPOD patients. No group differences we found in modularity of the identified networks. Both patient groups exhibited impaired connectivity when executing an olfactory task, while network modularity was significantly weaker for PD patients than both other groups. When performing a trigeminal task, no changes were found for PD patients, but NPOD patients exhibited impaired connectivity. Conversely, PD patients exhibited a significantly higher network modularity than both other groups. CONCLUSION In summary, the specific pattern of functional connectivity and chemosensory network recruitment in PD-related OD may explain distinct behavioral chemosensory features in PD when compared to NPOD patients and healthy controls.
Collapse
Affiliation(s)
- Cécilia Tremblay
- Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Behzad Iravani
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Émilie Aubry Lafontaine
- Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Jason Steffener
- Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Johan N Lundström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Johannes Frasnelli
- Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada.,Research Center, Sacré-Coeur Hospital of Montrealéal, Québec, Canada
| |
Collapse
|
5
|
Sorbera C, Brigandì A, Cimino V, Bonanno L, Ciurleo R, Bramanti P, Di Lorenzo G, Marino S. The impact of SARS-COV2 infection on people in residential care with Parkinson Disease or parkinsonisms: Clinical case series study. PLoS One 2021; 16:e0251313. [PMID: 33956891 PMCID: PMC8101942 DOI: 10.1371/journal.pone.0251313] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 04/24/2021] [Indexed: 11/26/2022] Open
Abstract
On March 2019 the World Health Organization declared Coronavirus disease (COVID-19) pandemic. Several recent reports disclose that the outcome of the infection is related to age, sex and can be influenced by underlying clinical conditions. Parkinson's disease (PD) and other parkinsonisms are the most common chronic disease which can cause, directly or indirectly, the patient to be more exposed to other diseases, mostly respiratory system's ones. Our primary outcome is to evaluate if PD patients are more susceptible than non-PD to take COVID-19 infection. Second, to detect if the infection course is worse in PD-COVID+ patients versus non-PD. This is a retrospective observational study on a cohort of 18 patients (13 PD- 5 non-PD), hospitalized in a Rehabilitative Unit during the occurrence of SARS-CoV2 epidemic outbreak. All patients performed laboratory tests, lung Computed Tomography (CT) and have been tested for COVID-19 thorough pharyngeal swab. PD and non-PD groups were comparable for age, gender and Hoehn and Yahr stage. Seventy-seven (77)% of PD and 60% of non-PD resulted positive for COVID-19. PD-COVID+ and PD-COVID- did not differ for age, disease duration and L-dopa daily dose. PD COVID-19+ subjects were mainly asymptomatic (50%) while non-PD ones were all symptomatic, mostly with respiratory difficulties. PD doesn't seem to be a risk factor to take SARS-COV2 infection, even if our study is related to a limited sample size. Our results, together with those of other recent studies, highlight the need to evaluate the actual susceptibility of patients with Parkinson's disease to develop COVID-19 disease, and how the infection may influence the risk of clinical worsening and increase of mortality.
Collapse
Affiliation(s)
| | | | | | - Lilla Bonanno
- IRCCS Centro Neurolesi “Bonino Pulejo”, Messina, Italy
| | | | | | | | - Silvia Marino
- IRCCS Centro Neurolesi “Bonino Pulejo”, Messina, Italy
| |
Collapse
|
6
|
Tremblay C, Frasnelli J. Olfactory-Trigeminal Interactions in Patients with Parkinson's Disease. Chem Senses 2021; 46:6218692. [PMID: 33835144 DOI: 10.1093/chemse/bjab018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Olfactory dysfunction (OD) is a highly frequent early non-motor symptom of Parkinson's disease (PD). An important step to potentially use OD for the development of early diagnostic tools of PD is to differentiate PD-related OD from other forms of non-parkinsonian OD (NPOD: postviral, sinunasal, post-traumatic, and idiopathic OD). Measuring non-olfactory chemosensory modalities, especially the trigeminal system, may allow to characterize a PD-specific olfactory profile. We here review the literature on PD-specific chemosensory alteration patterns compared with NPOD. Specifically, we focused on the impact of PD on the trigeminal system and particularly on the interaction between olfactory and trigeminal systems. As this interaction is seemingly affected in a disease-specific manner, we propose a model of interaction between both chemosensory systems that is distinct for PD-related OD and NPOD. These patterns of chemosensory impairment still need to be confirmed in prodromal PD; nevertheless, appropriate chemosensory tests may eventually help to develop diagnostic tools to identify individuals at risks for PD.
Collapse
Affiliation(s)
- Cécilia Tremblay
- Department of Anatomy, Université du Québec à Trois-Rivières, 3351 Boulevard des Forges, Trois-Rivières, QC, G9A 5H7, Canada
| | - Johannes Frasnelli
- Department of Anatomy, Université du Québec à Trois-Rivières, 3351 Boulevard des Forges, Trois-Rivières, QC, G9A 5H7, Canada.,Research Center, Sacré-Coeur Hospital of Montreal, 5400 Boulevard Gouin Ouest, Montréal, QC, H4J 1C5, Canada
| |
Collapse
|
7
|
Dahmer-Heath M, Schriever V, Kollmann S, Schleithoff C, Titieni A, Cetiner M, Patzer L, Tönshoff B, Hansen M, Pennekamp P, Gerß J, Konrad M, König J. Systematic evaluation of olfaction in patients with hereditary cystic kidney diseases/renal ciliopathies. J Med Genet 2020; 58:629-636. [PMID: 32917769 DOI: 10.1136/jmedgenet-2020-107192] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/01/2020] [Accepted: 07/12/2020] [Indexed: 12/31/2022]
Abstract
BACKGROUND Hereditary cystic kidney diseases such as nephronophthisis, polycystic kidney disease and Bardet-Biedl syndrome (BBS) are caused by a dysfunction of primary cilia. Cilia are involved in a variety of cellular functions and perceptions, with one of them being the sense of smell. Hyposmia is a typical feature found in patients with BBS. However, reports of olfactory dysfunction in other cystic kidney diseases are sparse. Here we provide a systematic survey on olfaction in a large cohort of patients displaying genetically determined renal ciliopathies. METHODS We performed a match-controlled systematic olfactory evaluation in a group of 75 patients with a defined genetic background using age adapted and validated odour identification tests. RESULTS Test results revealed a significant olfactory deficit in patients carrying TMEM67 variants (n=4), while all other genetic disorders causing nephronophthisis (n=25) or polycystic kidney disease (n=18) were not associated with an impaired sense of smell. Also in patients with BBS, olfactory performance was depending on the underlying molecular defect. While defects in the BBS1 gene (n=9) had no impact on the sense of smell, all other BBS gene disorders (n=19) were associated with significant hyposmia. Noteworthy, there was no correlation of the olfactory deficit with the level of renal impairment. CONCLUSION Hyposmia is a part of the clinical spectrum of BBS and of other renal ciliopathies. Depending on the genetic background, clinicians should be aware of this subtle and so far underappreciated symptom when clinically assessing patients with BBS or TMEM67 gene variants.
Collapse
Affiliation(s)
- Mareike Dahmer-Heath
- University Children's Hospital, Department of General Pediatrics, Universitätsklinikum Münster, Münster, Germany
| | - Valentin Schriever
- Abteilung für Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Dresden, Germany
| | - Sabine Kollmann
- University Children's Hospital, Department of General Pediatrics, Universitätsklinikum Münster, Münster, Germany
| | - Carolin Schleithoff
- University Children's Hospital, Department of General Pediatrics, Universitätsklinikum Münster, Münster, Germany
| | - Andrea Titieni
- University Children's Hospital, Department of General Pediatrics, Universitätsklinikum Münster, Münster, Nordrhein-Westfalen, Germany
| | - Metin Cetiner
- Department of Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Ludwig Patzer
- Children's Hospital St. Elisabeth and St. Barbara, Halle (Saale), Germany
| | - Burkhard Tönshoff
- Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
| | | | - Petra Pennekamp
- University Children's Hospital, Department of General Pediatrics, Universitätsklinikum Münster, Münster, Germany
| | - Joachim Gerß
- Institute of Biostatistics and Clinical Research, University of Münster, Münster, Germany
| | - Martin Konrad
- University Children's Hospital, Department of General Pediatrics, Universitätsklinikum Münster, Münster, Germany
| | - Jens König
- University Children's Hospital, Department of General Pediatrics, Universitätsklinikum Münster, Münster, Germany
| |
Collapse
|
8
|
Chase BA, Markopoulou K. Olfactory Dysfunction in Familial and Sporadic Parkinson's Disease. Front Neurol 2020; 11:447. [PMID: 32547477 PMCID: PMC7273509 DOI: 10.3389/fneur.2020.00447] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/27/2020] [Indexed: 12/26/2022] Open
Abstract
This minireview discusses our current understanding of the olfactory dysfunction that is frequently observed in sporadic and familial forms of Parkinson's disease and parkinsonian syndromes. We review the salient characteristics of olfactory dysfunction in these conditions, discussing its prevalence and characteristics, how neuronal processes and circuits are altered in Parkinson's disease, and what is assessed by clinically used measures of olfactory function. We highlight how studies of monogenic Parkinson's disease and investigations in ethnically diverse populations have contributed to understanding the mechanisms underlying olfactory dysfunction. Furthermore, we discuss how imaging and system-level approaches have been used to understand the pathogenesis of olfactory dysfunction. We discuss the challenging, remaining gaps in understanding the basis of olfactory dysfunction in neurodegeneration. We propose that insights could be obtained by following longitudinal cohorts with familial forms of Parkinson's disease using a combination of approaches: a multifaceted longitudinal assessment of olfactory function during disease progression is essential to identify not only how dysfunction arises, but also to address its relationship to motor and non-motor Parkinson's disease symptoms. An assessment of cohorts having monogenic forms of Parkinson's disease, available within the Genetic Epidemiology of Parkinson's Disease (GEoPD), as well as other international consortia, will have heuristic value in addressing the complexity of olfactory dysfunction in the context of the neurodegenerative process. This will inform our understanding of Parkinson's disease as a multisystem disorder and facilitate the more effective use of olfactory dysfunction assessment in identifying prodromal Parkinson's disease and understanding disease progression.
Collapse
Affiliation(s)
- Bruce A. Chase
- Department of Biology, University of Nebraska at Omaha, Omaha, NE, United States
| | - Katerina Markopoulou
- Department of Neurology, NorthShore University HealthSystem, Evanston, IL, United States
- Department of Neurology, University of Chicago, Chicago, IL, United States
| |
Collapse
|
9
|
Migneault-Bouchard C, Hsieh JW, Hugentobler M, Frasnelli J, Landis BN. Chemosensory decrease in different forms of olfactory dysfunction. J Neurol 2019; 267:138-143. [PMID: 31586261 DOI: 10.1007/s00415-019-09564-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/28/2019] [Accepted: 09/28/2019] [Indexed: 11/25/2022]
Abstract
The aim of this study is to investigate the effect of olfactory dysfunction (OD) on the two other chemical senses, namely gustation and the intranasal trigeminal system. Taste and trigeminal function were analyzed in a retrospective cross-sectional study of 178 participants with OD (n = 78 posttraumatic, n = 42 idiopathic, n = 27 post-infectious and n = 31 chronic rhinosinusitis (CRS) OD). All patients had been investigated for OD at our smell and taste outpatient clinic. Evaluation of olfaction was performed by means of the Sniffin' Sticks test (odor threshold, odor discrimination and odor identification), whereas gustatory function was assessed with the Taste Strips test and the intranasal trigeminal sensitivity by means of the lateralization task. The degree of olfactory impairment was found to depend on the cause of OD, but not on patients' age. Patients with posttraumatic OD showed lower olfactory function than patients with idiopathic, post-infectious and CRS OD (p = 0.01). Gustatory and trigeminal sensitivity in turn depended on age rather than the cause of olfactory dysfunction. Partial correlations between olfactory, gustatory, and trigeminal scores, with age as covariate, were significant, showing a decrease of taste and trigeminal function proportional to the OD (p < 0.05). The present data suggest that the three chemical senses are closely connected for humans underlining that in case of OD the remaining chemical senses (taste, trigeminal function) tend to decrease rather than compensate as this is seen for sensory loss in other modalities. This finding has direct clinical implications and importance when dealing with smell and taste disorders.
Collapse
Affiliation(s)
- Chloé Migneault-Bouchard
- Research Chair in Chemosensory Neuroanatomy, Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, QC, Canada
| | - Julien Wen Hsieh
- Department of Clinical Neuroscience, Geneva University Hospitals (HUG), Geneva, Switzerland.,Rhinology-Olfactology Unit, Department of Otorhinolaryngology, Head and Neck Surgery, Geneva University Hospitals (HUG), Geneva, Switzerland
| | - Marianne Hugentobler
- Rhinology-Olfactology Unit, Department of Otorhinolaryngology, Head and Neck Surgery, Geneva University Hospitals (HUG), Geneva, Switzerland
| | - Johannes Frasnelli
- Research Chair in Chemosensory Neuroanatomy, Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, QC, Canada.,Research Center of the Sacré-Coeur Hospital, Montreal, QC, Canada
| | - Basile Nicolas Landis
- Rhinology-Olfactology Unit, Department of Otorhinolaryngology, Head and Neck Surgery, Geneva University Hospitals (HUG), Geneva, Switzerland.
| |
Collapse
|
10
|
Tremblay C, Emrich R, Cavazzana A, Klingelhoefer L, Brandt MD, Hummel T, Haehner A, Frasnelli J. Specific intranasal and central trigeminal electrophysiological responses in Parkinson's disease. J Neurol 2019; 266:2942-2951. [PMID: 31451911 DOI: 10.1007/s00415-019-09517-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 01/20/2023]
Abstract
Olfactory dysfunction is a frequent early non-motor symptom of Parkinson's disease (PD). There is evidence that with regard to trigeminal perception, PD-related olfactory dysfunction is different from other olfactory disorders. More specifically, trigeminal sensitivity, when measured behaviorally, was unimpaired in PD patients as opposed to patients with non-Parkinsonian olfactory dysfunction (NPOD). We sought to investigate the trigeminal pathway by measuring electrophysiological recordings from the nasal epithelium and EEG-derived event-related potentials in response to a specific trigeminal stimulus in 21 PD patients and compare them to 23 patients with NPOD and 25 controls (C). The peripheral trigeminal response, as measured by the negative-mucosa potential, showed no difference between patients with PD and controls whereas PD patients showed faster responses than patients with NPOD, the latter having shown slower and larger responses than controls (18 PD, 14 NPOD, 20 C). The central trigeminal response, as measured by event-related potentials, revealed larger early component response in PD patients compared to patients with NPOD (15 PD, 21 NPOD, 23 C). As expected, psychophysical olfactory testing showed impaired olfactory function in both groups of patients as opposed to controls. Discriminant analysis revealed a model that could predict group membership for 80% of participants based on the negative-mucosa potential latency, olfactory threshold and discrimination tests. These results provide novel insights into the pattern of trigeminal activation in PD which will help to differentiate PD-related olfactory loss from NPOD, a crucial step towards establishing early screening batteries for PD including smell tests.
Collapse
Affiliation(s)
- Cécilia Tremblay
- Research Chair in Chemosensory Neuroanatomy, Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, QC, Canada.
| | - Rosa Emrich
- Department of Otorhinolaryngology, Smell and Taste Clinic, Technical University of Dresden, Dresden, Germany
| | - Annachiara Cavazzana
- Department of Otorhinolaryngology, Smell and Taste Clinic, Technical University of Dresden, Dresden, Germany
| | | | - Moritz D Brandt
- Department of Neurology, TU Dresden, Dresden, Germany.,German Center for Neurodegenerative Diseases (DZNE), Dresden, Germany
| | - Thomas Hummel
- Department of Otorhinolaryngology, Smell and Taste Clinic, Technical University of Dresden, Dresden, Germany
| | - Antje Haehner
- Department of Otorhinolaryngology, Smell and Taste Clinic, Technical University of Dresden, Dresden, Germany
| | - Johannes Frasnelli
- Research Chair in Chemosensory Neuroanatomy, Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, QC, Canada.,Research Center of the Sacré-Cœur Hospital, Montréal, QC, Canada
| |
Collapse
|
11
|
Abstract
Many odors activate the intranasal chemosensory trigeminal system where they produce cooling and other somatic sensations such as tingling, burning, or stinging. Specific trigeminal receptors are involved in the mediation of these sensations. Importantly, the trigeminal system also mediates sensitivity to airflow. The intranasal trigeminal and the olfactory system are closely connected. With regard to central nervous processing, it is most interesting that trigeminal stimuli can activate the piriform cortex, which is typically viewed as the primary olfactory cortex. This suggests that interactions between the two systems may form at a relatively early stage of processing. For example, there is evidence showing that acquired olfactory loss leads to reduced trigeminal sensitivity, probably on account of the lack of interaction in the central nervous system. Decreased trigeminal sensitivity may also be responsible for changes in airflow perception, leading to the impression of congested nasal airways.
Collapse
Affiliation(s)
- Thomas Hummel
- Department of Otorhinolaryngology, Smell and Taste Clinic, Technische Universität Dresden, Dresden, Germany.
| | - Johannes Frasnelli
- Université du Québec à Trois-Rivières, Department of Anatomy, Trois-Rivières, QC, Canada
| |
Collapse
|