An observational study in Olfactory Dysfunction, Chronic Rhinosinusitis With Nasal Polyps (CRSwNP) and Functional Magnetic Resonance Imaging (fMRI), sponsored by Rigshospitalet, Denmark. Not yet recruiting at 1 site in Denmark. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-14.
Sponsored by Rigshospitalet, Denmark · Observational
This project will focus on rehabilitation of olfactory dysfunction in patients with chronic rhinosinusitis with polyps given biological treatment based on functional magnetic resonance imaging.
The sense of smell is essential in social interactions, food intake and hazard detection. Olfactory dysfunction (OD) affects approximately 20% of the adults and likely increased following the COVID-19 pandemic. The pandemic highlighted the substantial burden of OD on daily life and well-being.
A common cause of acquired OD is Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) affecting 2-4% of adult Scandinavian population. The vast majority of CRSwNP in this population is driven by type-2 inflammation. Decreased sense of smell is an almost obligatory complaint in severe CRSwNP with an OD prevalences of \~95% and ranked as one of the most important.
OD is the symptom in CRSwNP with greatest effect on health-related quality of life and at the same time remains difficult to treat.
New treatments for patients with severe CRSwNP have recently become available in form of monoclonal antibodies selectively blocking pro-inflammatory cytokines in the type-2-inflammation cascade. These biologics show substantial improvements in self-reported olfactory tests.
Knowledge of neuroanatomical functional and structural correlates to olfactory function has long existed. However, only few have used functional magnetic resonance imaging (fMRI) to investigate OD in CRS patients. Patients with CRS-related OD offer a unique neurobiological model for studying olfactory plasticity as olfaction potentially improves.
This study aims to determine whether improvement in olfaction represented by TDI scores after medical treatment with biologics (anti IL-5 or anti IL-4/13) for severe CRSwNP is accompanied by functional changes in olfactory brain ROIs as represented by differences in representational dissimilarity matrixes (RDMs).
Patients with olfactory dysfunction (OD) due to CRSwNP are recruited before or shortly after their first injection of monoclonal antibodies/biologic therapy. Nasal endoscopy and a validated olfactory test (TDI) are performed. Participants also undergo fMRI, during which they are presented with three different odors that they are asked to categorize. A group of age- and sex-matched healthy controls with normal olfactory function and no disease of the nasal or paranasal sinus system undergoes the same assessments.
All examinations are repeated in both groups after 24 weeks +/- 2 weeks..
By constructing RDMs based on fMRI-data we will invesitage how central olfactory processing changes following 24 weeks of biologic treatment and whether these neural changes are associated with improvements in olfactory performance.
236 studies on the registry are indexed under Nasal Polyps; 68 are open to participants now.
This study's planned enrollment of 40 is below the median of 100 across 47 observational studies indexed under Nasal Polyps.
Browse Nasal Polyps studies →Rigshospitalet, Denmark is the lead sponsor of 1,007 studies on the registry; 175 are open to participants now.
Counted across the registry records on this site, refreshed daily.
A study population of patients form the out-patient clinic at Copenhagen University Hospital, Rigshospitalet with CRSwNP offered treatment with biologics meeting the criteria for treatment with biologic as stated in the European Position Paper on Rhinosinusitis and Nasal Polyps 2020 (EPOS 2020) as well as the Danish Medicines Council criteria to be considered for inclusion.
Furthermore, healthy controls matched by sex and age recruited through advertisement.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
for MRI scan including:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients with olfactory dysfunction due to chronic rhinosinusitis with nasal polyps who are navïe to biological treatment
Age-adsjusted, normoosmic and sinus healthy matched controls
This study also gives Dupilumab. No intervention listed here names it: that was found by reading the record.
Representational Similarity Matrix (RDM)
Change in representational dissimilarity matrices (RDMs) derived from functional magnetic resonance imaging (fMRI) data during an odor categorization task. RDMs will be constructed from multivoxel activation patterns elicited by three odor stimuli within predefined olfactory regions of interest
Time frame: From enrollment to 24 weeks +/- 2 weeks
Threshold-Discrimination-Identification (TDI) score
Changes in olfactory function measured by Sniffin' Sticks Threshold-Discrimination-Identification (TDI) score
Time frame: Baseline and Week 24 (±2 weeks)
Correlation between changes in RDM metrics and changes in TDI score.
Evaluation of the relationship between treatment-related changes in neural olfactory representations and clinical improvements in olfactory performance.
Time frame: Baseline and Week 24 (±2 weeks)
Plan to share: No — Individual participant data will not be made publicly available. De-identified data may be shared with collaborating investigators as part of an established research collaboration and in accordance with ethical approvals, General Data Protection Regulation (GDPR) and the Danish Data Protection Act.
No publications or documents are linked to this record.
Start is estimated for Jun 2027; primary completion for Jun 2029, 24 months later.
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This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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