AnosmiaNCT05912881
Chemosensory Dysfunction and Recovery in Endoscopic Endonasal Skull Base Surgery
A study testing Olfactory training in people with Anosmia and Skull Base Neoplasms, run by Johns Hopkins University at 1 site in United States.
Trial summary
The investigators hypothesize that patients undergoing endoscopic endonasal skull base surgery experience clinically meaningful and modifiable disruptions in postoperative chemosensory function and quality of life, and the investigators further hypothesize that olfactory training in the postoperative period may… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Anosmia, Skull Base Neoplasms
- What is being tested?
- Olfactory training
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 41 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Feb 2023to 1 Jan 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- English Speaking
- preoperative diagnosis of benign sellar or parasellar skull base pathology
Who cannot join
- preoperative diagnosis of malignant sellar or parasellar skull base pathology
- history of endoscopic sinus surgery
- history of skull base surgery
- history of radiation therapy or other local treatments for the management of facial, sinonasal, or cranial pathologies
- history of chronic rhinosinusitis
- history of neurocognitive disorder
Show all 9Show fewer
- history of intrinsic chemosensory pathology
- history of cardiac pacemaker
- history of gastrectomy
Trial locations and contacts
1 site in 1 country.
About this study
The investigators hypothesize that patients undergoing endoscopic endonasal skull base surgery experience clinically meaningful and modifiable disruptions in postoperative chemosensory function and quality of life, and the investigators further hypothesize that olfactory training in the postoperative period may significantly hasten normalization of patients' chemosensory perturbations. This tailored prospective study seeks to fulfill a significant gap in the understanding of the characteristics, implications, and treatment options for postoperative olfactory and gustatory impairment following endoscopic endonasal skull base surgery.
- Conditions
- Anosmia, Skull Base Neoplasms
- Being tested
- Olfactory training, Placebo training
- Medical subject headings
- Anosmia, Skull Base Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Olfactory trainingOther
Participants perform olfactory training using sticks filled with scented essential oils.
Placebo trainingOther
Participants perform olfactory training using sticks filled with unscented medium chain triglycerides.
| Study group | Role | What they receive |
|---|---|---|
| Placebo | Placebo comparator | Participants receive placebo olfactory training kits that only contain medium chain triglycerides that lack any discernible odor Receives: Other: Placebo training |
| Treatment | Experimental | Participants receive treatment olfactory training kits that contain essential oils that have scents (lavender, lemon, clove, eucalyptus) Receives: Other: Olfactory training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Olfactory function as assessed by the Sniffin Sticks olfactory testing kit
Olfactory function as determined using the commercially available "Sniffin' Sticks" olfactory testing kit. Olfactory function is tested in three domains: threshold, discrimination, and identification. For threshold testing, the most dilute concentration of odorant that the participant is able to reliably detect is determined. In discrimination testing, the participant is evaluated on their ability to discern the unique scent among three scented sticks. In identification testing, the patient names the smells using a multiple choice form which offers four definitions for every Sniffin' stick, only one of which is correct.
Measured: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative
Secondary outcomes (4)
Change in Quality of Life as assessed by the Anterior Skull Base Nasal Inventory-12
Quality of life questionnaire. Score range 0-60, where higher score is worse and indicates more onerous symptoms.
Measured: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative, 6 months post-operative
Change in Quality of Life as assessed by the ODOR (Olfactory Dysfunction Outcomes Rating) questionnaire
Quality of life questionnaire. Score range 0-112, where higher score is worse and indicates greater degree of olfactory dysfunction.
Measured: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative, 6 months post-operative
Change in Quality of Life as assessed by the Skull Base Inventory
Quality of life questionnaire. Score range 0-100, where higher score is better, indicative of less burden on quality of life.
Measured: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative, 6 months post-operative
Change in Quality of smell and taste as assessed by a Visual analog scale
Quality of smell and taste as indicated on a visual analog scale. Score range 0-100, where higher score is better and indicative of better smell and taste function.
Measured: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative, 6 months post-operative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jun 2023
- Study start1 Feb 2023
- Primary completion1 Jan 2026
- Study completion1 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AnosmiaStudies of the same condition, open and under way.
- More trials run by Johns Hopkins UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants are enrolled into treatment or placebo groups for the entirety of the study.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 41 participants (actual)
Sponsor and investigators
- Lead sponsor
- Johns Hopkins University
- Sponsor type
- University, hospital or other
- Collaborators
- North American Skull Base Society
- Responsible party
- Sponsor
- Investigators
- Nicholas Rowan, MD, Principal investigator, Johns Hopkins School of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05912881
- Sponsor's protocol ID
- IRB00311777
- Status last verified
- Feb 2026
- First submitted
- 2 Jun 2023
- Last updated
- 18 Feb 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Chemosensory Dysfunction and Recovery in Endoscopic Endonasal Skull Base Surgery
- ClinicalTrials.gov ID
- NCT05912881
- Acronym / sponsor ID
- IRB00311777
- Conditions
- Anosmia, Skull Base Neoplasms
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 41 participants (actual)
- Lead sponsor
- Johns Hopkins UniversityUniversity, hospital or other
- Collaborators
- North American Skull Base Society
- Study start
- 1 Feb 2023 (actual)
- Primary completion
- 1 Jan 2026 (actual)
- Study completion
- 1 Jan 2026 (actual)
- First posted
- 22 Jun 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The investigators hypothesize that patients undergoing endoscopic endonasal skull base surgery experience clinically meaningful and modifiable disruptions in postoperative chemosensory function and quality of life, and the investigators further hypothesize that olfactory training in the postoperative period may significantly hasten normalization of patients' chemosensory perturbations. This tailored prospective study seeks to fulfill a significant gap in the understanding of the characteristics, implications, and treatment options for postoperative olfactory and gustatory impairment following endoscopic endonasal skull base surgery.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Participants are enrolled into treatment or placebo groups for the entirety of the study.
| Arm | Type | Receives |
|---|---|---|
| Placebo | Placebo comparator | Other: Placebo trainingParticipants receive placebo olfactory training kits that only contain medium chain triglycerides that lack any discernible odor |
| Treatment | Experimental | Other: Olfactory trainingParticipants receive treatment olfactory training kits that contain essential oils that have scents (lavender, lemon, clove, eucalyptus) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- English Speaking
- preoperative diagnosis of benign sellar or parasellar skull base pathology
Key exclusion criteria (9 listed)
- preoperative diagnosis of malignant sellar or parasellar skull base pathology
- history of endoscopic sinus surgery
- history of skull base surgery
- history of radiation therapy or other local treatments for the management of facial, sinonasal, or cranial pathologies
- history of chronic rhinosinusitis
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Olfactory trainingParticipants perform olfactory training using sticks filled with scented essential oils. | Other | Treatment |
| Placebo trainingParticipants perform olfactory training using sticks filled with unscented medium chain triglycerides. | Other | Placebo |
Primary outcome
Change in Olfactory function as assessed by the Sniffin Sticks olfactory testing kit
Time frame: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative
Olfactory function as determined using the commercially available "Sniffin' Sticks" olfactory testing kit. Olfactory function is tested in three domains: threshold, discrimination, and identification. For threshold testing, the most dilute concentration of odorant that the participant is able to reliably detect is determined. In discrimination testing, the participant is evaluated on their ability to discern the unique scent among three scented sticks. In identification testing, the patient names the smells using a multiple choice form which offers four definitions for every Sniffin' stick, only one of which is correct.
4 secondary outcomes
Change in Quality of Life as assessed by the Anterior Skull Base Nasal Inventory-12
Time frame: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative, 6 months post-operative
Change in Quality of Life as assessed by the ODOR (Olfactory Dysfunction Outcomes Rating) questionnaire
Time frame: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative, 6 months post-operative
Change in Quality of Life as assessed by the Skull Base Inventory
Time frame: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative, 6 months post-operative
Change in Quality of smell and taste as assessed by a Visual analog scale
Time frame: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative, 6 months post-operative
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Feb 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Nicholas Rowan, MD principal investigator
Johns Hopkins School of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Olfactory training in people with Anosmia and Skull Base Neoplasms, run by Johns Hopkins University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Olfactory function as assessed by the Sniffin Sticks olfactory testing kit (time frame: Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Feb 2026.