Olfactory and Neurosensory Rehabilitation in Coronavirus 2019 (COVID-19)-Related Olfactory Dysfunction (OD)
Trial Snapshot
- Phase
- Phase 2
- Sponsor
- Enrollment
- 25
- Locations
- 2
- Primary Endpoint
- Objective olfactory assessment by the butanol threshold test (BTT)
Study Overview
Brief Summary
A combination of oral vitamin A (VitA) and intense aromatic chemosensory smell training (ST) by pulse aromatic stimulation will expedite the neurosensory recovery of olfaction in patients suffering from prolonged COVID-19-related olfactory dysfunction (OD).
Detailed Description
This is an open-labeled randomised-controlled trial (RCT) investigating the safety and therapeutic efficacy of oral VitA in combination with ST for patients suffering from prolonged COVID-19-related OD.
Prior to the initiation of treatment, all patients will receive subjective and objective olfactory assessments. Comprehensive ear, nose, and throat (ENT) examination will be performed to rule out alternative causes of OD. All participants will receive resting-state functional magnetic resonance imaging (rs-fMRI) of the brain before treatment as baseline evaluation.
Patients with prolonged COVID-19-related OD will be assigned to the intervention (group A or B) or control (group C) arms:
Intervention arm A. 14-day course of daily oral VitA 7500µg RAE (retinol activity equivalents) in combination with ST three times per day for 4 weeks; or B. ST three times per day for 4 weeks alone; or
Control arm C. Observation
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Double (Investigator, Outcomes Assessor)
Masking Description
All study participants will receive baseline and follow up resting-state functional (rs-fMRI) brain scans during the study period. The radiologists assessing and analysing the rs-fMRI images will be blinded to the treatment regimens received by the study subjects.
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Adult out-patient (≥18 years of age)
- •Previously diagnosed with coronavirus disease 2019 (COVID-19) by laboratory confirmation using reverse transcriptase polymerase chain reaction (RT-PCR) for the detection of severe acute respiratory virus coronavirus 2 (SARS-CoV-2)
- •Complaints of persistent olfactory disturbances, subjectively
- •Quantitatively documented to have olfactory dysfunction by
- •Butanol threshold test (BTT)
- •Smell identification test (SIT)
- •All subjects give written informed consent
- •Subjects must be available to complete the study and comply with study procedures.
Exclusion Criteria
- •Inability to comprehend and to follow all required study procedures
- •Allergy or severe reactions to the study drug or smell training
- •Pregnant or breastfeeding women
- •Pre-existing factors which may account for persistent olfactory dysfunction besides COVID-19 (e.g. nasal polyps, obstructive lesions within the nasal cavity, severe anatomical malformations...)
- •Received an experimental agent (vaccine, drug, biologic, device, blood product, or medication) within 1 month prior to recruitment in this study or expect to receive an experimental agent during this study. Unwilling to refuse participation in another clinical study through the end of this study.
- •Have any condition that the investigator believes may interfere with successful completion of the study.
Arms & Interventions
Vitamin A and smell training
14-day course of daily oral vitamin A 7500µg RAE in combination with smell training three times per day for 4 weeks
Intervention: Vitamin A (Drug)
Vitamin A and smell training
14-day course of daily oral vitamin A 7500µg RAE in combination with smell training three times per day for 4 weeks
Intervention: Electronic portable aromatic rehabilitation (EPAR) diffuser (Device)
Smell training
Smell training three times per day for 4 weeks
Intervention: Electronic portable aromatic rehabilitation (EPAR) diffuser (Device)
Outcomes
Primary Outcomes
Objective olfactory assessment by the butanol threshold test (BTT)
Time Frame: 4 weeks
Objective measurements of olfactory sensitivity, as determined by the detection of different concentrations of butanol.
Objective olfactory assessment by the smell identification test (SIT)
Time Frame: 4 weeks
Objective categorization of olfactory status by the smell identification test (SIT).
Subjective olfactory assessment
Time Frame: 4 weeks
Subjective olfactory assessment by the Sino-Nasal Outcome Test (SNOT-22).
Secondary Outcomes
- Interim neuroradiological changes after oral vitamin A in combination with smell training versus smell training alone(2 weeks)
- Neuroradiological brain changes in the intervention group versus healthy control group at the end of study(4 weeks)
- Neuroradiological changes after olfactory treatment at the end of study(4 weeks)
- Neuroradiological brain changes in the intervention group versus observation group at the end of study(4 weeks)
- Interim neuroradiological changes after 2 weeks of olfactory treatment(2 weeks)
Investigators
Ivan FN Hung MD
Professor
The University of Hong Kong