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Does Olfactory Training Improve Olfaction in a Population With Normal Sense of Smell?

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ClinicalTrials.gov Identifier: NCT02980718
Recruitment Status : Recruiting
First Posted : December 2, 2016
Last Update Posted : October 2, 2017
Sponsor:
Collaborator:
Information provided by (Responsible Party):

Study Description
Brief Summary:

Awareness of the sense of smell in the western population has been low. Most people do not think about the consequences of absence of smell (anosmia). Reduction in sense of smell (hyposmia) can influence everyday life. In situations of stress anosmia can be life threatening for example when there is a fire. Cooks may lose their job. Not being able to enjoy food and drink interferes with quality of life. The causes of olfactory dysfunction (OD) vary. Most often OD is associated with upper respiratory tract infections, disease of the nose and sinuses or head injuries. OD may be congenital, age related or associated with neurological disorders. Hyposmia occurs in up to 85% of cases of Parkinson's and may be the first symptom of both Parkinson's and Alzheimer's disease several years before the mental changes occur.

Knowledge and focus on OD has until recently been low among most physicians and treatment options have often not been available. Different approaches to improve OD have been tried with variable effect depending on the cause of OD. There are studies on corticosteroids, zinc gluconate and vitamin A. In recent years, olfactory training has been launched as a promising treatment option. Most studies with olfactory training are done with patients with OD. A recently published review describes 10 studies with olfactory training among 639 patients and concludes that daily stimulation with odorants (odor concentrate) over a limited period time is a promising treatment. The suggested duration of olfactory training varies from 3 to 14 months. Different intensities of olfactory training were compared in patients with post-viral OD. Olfaction was more improved by the high concentration of odorant than by the low concentration.

A small number of studies have shown that the olfactory nerve to some extent can be trained in persons with normal sense of smell, but we need more experience and structured studies to be able to conclude with greater certainty about the effect of olfactory training in this population.

This study examines whether intensive olfactory training improves the sense of smell more than ordinary olfactory training in subjects with normal olfaction (normosmia) and examines self-evaluation of olfactory function.


Condition or disease Intervention/treatment
People With Normal Sense of Smell Behavioral: intensive olfactory training Behavioral: ordinary olfactory training

Detailed Description:
Sub-study: Part of the participants (45/200) will be included in a pilot study which will be an analytical observational study to compare olfactory bulb volume measured on MRI three times during a year, while at the same time resting state fMRI will be measured before and after olfactory training. There is not sufficient data in the literature for power calculations and this sub-study is therefore a pilot study.

Study Design

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 200 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Does Olfactory Training Improve Olfaction in a Population With Normosmia and How is Their Self Assessment of Sense of Smell?
Actual Study Start Date : December 2016
Estimated Primary Completion Date : December 2019
Estimated Study Completion Date : December 2019
Arms and Interventions

Arm Intervention/treatment
Experimental: intensive olfactory training
90 participants will undergo intensive olfactory training. They will sniff on four selected odors (10 seconds on each odor bottle in a total of 4 minutes) every morning and evening for 3 months and they will be instructed in the principles of the logbook for olfactory training.
Behavioral: intensive olfactory training
Experimental: ordinary olfactory training
90 participants will undergo ordinary olfactory training. They will sniff on four selected odors (10 seconds on each odor bottle in a total of 40 seconds) every morning and evening for 3 months and they will be instructed in the principles of the logbook for olfactory training.
Behavioral: ordinary olfactory training
No Intervention: controls
20 participants represent a control group with no olfactory training


Outcome Measures

Primary Outcome Measures :
  1. olfaction assessed by TDI-score according to extended Sniffin`Sticks [ Time Frame: 4 months (immediately after completion of the training period) ]
  2. olfaction self-evaluated and reported in a questionnaire [ Time Frame: 4 months (immediately after completion of the training period) ]

Secondary Outcome Measures :
  1. olfaction assessed byTDI-score according to extended Sniffin`Sticks [ Time Frame: 1 year (6-7 months after completion of the training period) ]
  2. olfaction self-evaluated and reported in a questionnaire [ Time Frame: 1 year (6-7 months after completion of the training period) ]

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • TDI score > 30.5 measured by Sniffin`Sticks

Exclusion Criteria:

  • Not able to follow the olfactory training or follow-up (language, practical implementation, mental condition)
  • Disease affecting olfaction (sinusitis, pronounced allergies, recent nasal surgery, Alzheimer's, Parkinson, MS, COPD)
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02980718


Contacts
Contact: Mette Bratt, md mette.bratt@stolav.no
Contact: Anne Helvik, md phd anne.helvik@stolav.no

Locations
Norway
St Olavs Hospital Recruiting
Trondheim, Norway
Contact: Mette Bratt, MD       mette.bratt@stolav.no   
Sponsors and Collaborators
St. Olavs Hospital
Norwegian University of Science and Technology
Investigators
Study Director: Ståle Nordgård, md prof Norwegian University of Science and Technology
More Information

Publications:
Responsible Party: St. Olavs Hospital
ClinicalTrials.gov Identifier: NCT02980718     History of Changes
Other Study ID Numbers: 2016/837
First Posted: December 2, 2016    Key Record Dates
Last Update Posted: October 2, 2017
Last Verified: September 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by St. Olavs Hospital:
Olfaction training
Smell