Chemosensory Dysfunction and Recovery in Endoscopic Endonasal Skull Base Surgery

February 16, 2026 updated by: Johns Hopkins University
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 Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

41

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Maryland
      • Baltimore, Maryland, United States, 21224
        • Johns Hopkins Medicine

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • English Speaking
  • preoperative diagnosis of benign sellar or parasellar skull base pathology

Exclusion Criteria:

  • 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
  • history of intrinsic chemosensory pathology
  • history of cardiac pacemaker
  • history of gastrectomy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
Participants receive placebo olfactory training kits that only contain medium chain triglycerides that lack any discernible odor
Other: Placebo training
Participants perform olfactory training using sticks filled with unscented medium chain triglycerides.
Experimental: Treatment
Participants receive treatment olfactory training kits that contain essential oils that have scents (lavender, lemon, clove, eucalyptus)
Other: Olfactory training
Participants perform olfactory training using sticks filled with scented essential oils.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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
Quality of life questionnaire. Score range 0-60, where higher score is worse and indicates more onerous symptoms.
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
Quality of life questionnaire. Score range 0-112, where higher score is worse and indicates greater degree of olfactory dysfunction.
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
Quality of life questionnaire. Score range 0-100, where higher score is better, indicative of less burden on quality of life.
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
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.
Pre-operative visit (baseline), 2 weeks post-operative, 1 month post-operative, 3 months post-operative, 6 months post-operative

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Johns Hopkins University

Collaborators

North American Skull Base Society

Investigators

  • Principal Investigator: Nicholas Rowan, MD, Johns Hopkins School of Medicine

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 1, 2023

Primary Completion (Actual)

January 1, 2026

Study Completion (Actual)

January 1, 2026

Study Registration Dates

First Submitted

June 2, 2023

First Submitted That Met QC Criteria

June 20, 2023

First Posted (Actual)

June 22, 2023

Study Record Updates

Last Update Posted (Actual)

February 18, 2026

Last Update Submitted That Met QC Criteria

February 16, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB00311777

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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