Longitudinal Deep Phenotyping of Central Mechanisms in Dysosmia: A Pilot Study Using Electrobulbo… (NCT07149428) | Clinical Trial Compass
By InvitationNot Applicable
Longitudinal Deep Phenotyping of Central Mechanisms in Dysosmia: A Pilot Study Using Electrobulbogram (EBG), Functional MRI (fMRI), and Diffusion-Weighted Imaging (DWI)
United States80 participantsStarted 2026-07-01
Plain-language summary
Background:
Loss of the sense of smell can seriously affect a person's quality of life. The ability to smell can be damaged by many factors, including illnesses, injuries, and exposure to toxic chemicals. The effects can vary, including complete loss of smell, partial loss, and parosomia, which is when things smell differently than they should.
Objective:
To study how brain function changes in people with different types of smell disorders. Also, to look at how smell loss affects quality of life over time.
Eligibility:
People aged 18 years or older with a disorder that affects their sense of smell. Healthy volunteers are also needed.
Design:
Participants will have 5 study visits over 1 year. They will have various tests and procedures:
Smell tests. They will have several tests that involve smelling different items and answering questions.
Questionnaires. They will answer questions about their health, mood, sense of smell, and daily habits.
Magnetic resonance imaging (MRI) scans. They will lie on a bed that slides into a tube. Padding will hold their head still. They will smell different odors while in the scanner.
Electrobulbogram (EBG). They will wear a soft cap with sensors that measure brain activity. They will smell different odors while wearing the cap.
Nasal endoscopy. A flexible tube will be inserted into a nostril to view the inside of the nose.
Biopsy. A numbing substance will be sprayed into the nose. Then a scissor-like tool will be used to collect a sample of tissue from one or both nasal passages.
Samples of blood, urine, and nasal fluid will be taken.
Who can participate
Age range
18 Years – 99 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Adult subjects, any sex, aged 18 or older.
. Ability to understand and willingness to sign a written informed consent document.
. Willingness and ability to comply with and participate in all study procedures and availability for the duration of the study.
. Due to the extensive questionnaires (administered in English language only) that participants must complete independently, fluency in the English language is needed. Hence, participants must be able to read and understand English.
. General Smell Loss:
. Post-COVID-19 or Virus-Related Smell Loss:
. Sinonasal Smell Loss:
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1This trial is enrolling by invitation only — can you tell me whether I might be eligible to be invited based on my specific diagnosis, and what the process for that would look like?
2Since this is listed as a pilot observational study rather than a treatment trial, does participating involve any experimental treatments, or is it purely about brain imaging and smell testing to better understand olfactory dysfunction?
3The study uses fMRI, diffusion-weighted imaging, and something called an electrobulbogram — can you explain what each of these procedures involves in practice, and whether any of them carry risks I should know about?
4Given that my smell disorder may be related to COVID-19, a respiratory infection, or another cause, does my specific underlying condition affect whether my doctor thinks this kind of study would be a meaningful fit for my situation right now?
5Since this is a longitudinal study, how many visits or sessions would likely be required over time, and is that level of commitment realistic given everything else I'm managing with my health right now?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Functional Connectivity Differences in Olfactory Dysfunction
Timeframe: baseline, 3, 6, 9 and 12 months
Trial details
NCT IDNCT07149428
SponsorNational Institute on Deafness and Other Communication Disorders (NIDCD)