Clinical trial NCT05562050: Characteristics of the Anosmic Olfactory Mucosa
Official title: Characteristics of the Anosmic Olfactory Mucosa
Study type: OBSERVATIONAL
Overall status: ACTIVE_NOT_RECRUITING
Conditions: Anosmia
COVID-19
Head Injury
Lead sponsor: Regional Hospital West Jutland
Sponsor class: OTHER
First posted: 2022-09-30
Enrollment: 18
Sex: ALL
Minimum age (years): 25
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: recruited from the clinic

Brief summary: The present study aims to describe the structural tissue and cell characteristics of the olfactory mucosa in patients with persistent anosmia (≥2 years) due to COVID-19 or head-trauma, in comparison to healthy individuals with intact olfactory function. In order to avoid possible age-related degenerative changes in the neuro-epithelium, both patients and controls are between 25 and 35 years of age.


Eligibility criteria: Inclusion Criteria:

* Legally competent to vouch for their own study participation.
* Informed and written consent for participation in this study.
* Study group 1 (Post-COVID anosmia)

  1. Diagnosed with persistent anosmia for approximately two years concurring with positive SARS-CoV-2 PCR-test between 2019 and 2020.
  2. Sniffin'sticks test with a threshold-discrimination-identification-score(TDI)≤16
  3. Between 25 and 35 years of age.

Study group 2 (Post-trauma anosmia)

1. Diagnosed with persistent anosmia for approximately two years concurring with head trauma.
2. Sniffin'sticks test with a threshold-discrimination-identification-score(TDI)≤16
3. Between 25 and 35 years of age.

Study group 3 (Controls):

1. Between 25 and 35 years of age.
2. Undergoing reposition of a nasal fracture in general anaesthesia

Exclusion Criteria:

* \<25 years of age.
* \>35 years of age.
* Chronic rhinosinusitis with/without polyps.
* Nasal cancer.
* Presence of viral or bacterial rhinosinusitis.
* Uncontrolled allergic rhinosinusitis.
* Coagulation deficiencies, e.g. haemophilia.
* Use of anticoagulants.
* Not able to undergo general anaesthesia.
* Pregnancy.
* Any use of nasal detumescence drugs ≤2 weeks before biopsy.
* Any use of nasal steroids ≤3 months before biopsy.
* Use of nasal inhaled recreational drugs ≤3 month before biopsy.
* Participants not able to communicate in Danish or English.
* Major Depression Inventory (MDI) score ≥27 \[49, 50\]
* Mini Mental State Examination (MMSE) score ≤ 26 \[51\]
* Study group 1 (Post-COVID anosmia)

  1. Anosmia for less than two years or more than two and a half years.
  2. No positive SARS-CoV-2 PCR-test concurring with olfactory dysfunction.
  3. History of olfactory dysfunction before COVID-19 infection.
* Study group 2 (Post-trauma anosmia)

  1. Anosmia for less than two years or more than approximately two-three years.
  2. Anosmia without concurring with head trauma
  3. History of prior olfactory dysfunction before head trauma.
* Study group 3 (Controls) 1. Known olfactory dysfunction.

Primary outcomes:
measure: Histological evaluation
timeFrame: 2023-2024
measure: Immunohistochemical evaluation
timeFrame: 2023-2024
Secondary outcomes:
Other outcomes:
Locations:
city: Herning
country: Denmark
facility: ENT department
Study officials:
affiliation: Regional Hospital Gødstrup
name: Therese Ovesen, DMSc
role: PRINCIPAL_INVESTIGATOR
References: