Olfaction Disorders, Smell Disorders, Anosmia, Hyposmia, Olfactory Impairment, Smell Loss, Smell Dysfunction
Conditions
Brief summary
* Causes of olfactory dysfunction can be classified into conductive and sensorineural causes. * Conductive causes are mainly due to structural nasal problem, which can be treated by nasal surgery * Sensorineural causes included post-infection, post-head injury, post Head and Neck irradiation and other central nervous system diseases. * Olfactory Training is well established treatment for sensorineural olfactory dysfunction in foreign countries. * Olfactory Training by neurological chemosensory stimulation using aromatic substances delivered via electronic portable aromatic rehabilitation (EPAR) diffuser was proved to be effective treatment in COVID-19 related olfactory dysfunction in recent Hong Kong study. * However, there is a lack of local study on the effect of Olfactory Training in other non-COVID-19 sensorineural causes of olfactory dysfunction in Hong Kong population.
Detailed description
Design Prospective double-blinded randomized control trial. Study Period 1/7/2022 - 30/6/2024 for case recruitment. Suitable patient will be recruited. Informed consent will be signed. Objective smell assessment will be done using the University of Pennsylvania Smell Identification Test (UPSIT) and Butanol Threshold Test (BTT). Subjective quality of life score will be obtained by Sino-Nasal Outcome Test (SNOT-22). Subjective smell and taste assessment will be assessed by Visual Analogue Scale (VAS). Patient will be randomized into treatment group and control group using computer generated list by an independent nursing staff. Doctors and the patients will be blinded during the study.
Interventions
OTHEROlfactory Training
Four aromatic substances will be used (Citrus limon, Eucalyptus radiata, Pelargonium graveolens, Juniperus virginiana)
OTHERControl
Normal Saline will be used
Sponsors
Pamela Youde Nethersole Eastern Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Investigator)
Masking description
Randomly assigned by computer into treatment group and control group
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Olfactory dysfunction \> 6 months and \< 5 years
Exclusion criteria
* History of significant head injury (fracture, ICH) * History of brain surgery * History of nasal surgery * Active nasal disease * Active neurological disease * Poor premorbid status/ non-communicable patients * Mentally incompetent patients * \<18 years' old * Pregnancy * Hypersensitivity to the aromatic substance.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Olfactory threshold changes after olfactory training after 3 months | 3 months after starting smell training | Parameter: Olfactory threshold using Butanol Threshold Test (BTT) |
| Olfactory identification score changes after olfactory training after 3 months | 3 months after starting smell training | Parameter: Olfactory identification using Smell Identification Test (UPSIT) |
| Quality of life changes after olfactory training after 3 months | 3 months after starting smell training | Parameter: Subjective quality of life score using Sino-Nasal Outcome Test (SNOT-22) |
| Taste and smell changes after olfactory training after 3 months | 3 months after starting smell training | Parameter: Subjective smell and taste assessment using Visual Analogue Scale (VAS) |
Countries
Hong Kong
Contacts
Primary ContactKai Chuen Fergus Wong, FRCSEd(ORL)
Backup ContactKa Chung Kwan, FRCSEd(ORL)
Outcome results
None listed