Chemosensory Dysfunction and Recovery in Endoscopic Endonasal Skull Base Surgery

Study Overview
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Brief Summary
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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.

Official Title
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Chemosensory Dysfunction and Recovery in Endoscopic Endonasal Skull Base Surgery

Conditions
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Anosmia, Skull Base Neoplasms

Intervention / Treatment
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* Other: Olfactory training
* Other: Placebo training


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants are enrolled into treatment or placebo groups for the entirety of the study.
Masking: Quadruple


Arms and Interventions

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

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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. | 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 | 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 | 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 | 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 | 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 |