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. 2025 Aug 13;15(8):e100880.
doi: 10.1136/bmjopen-2025-100880.

Assessing modified olfactory training to prevent cognitive decline in MCI high-risk individuals: a multicentre randomised controlled trial protocol in Beijing tertiary hospitals

Chia-Yi Lin #  1   2 , Yangzi Tan #  1   2 , Danhua Zhao  3 , Dawei Wu  4
Affiliations

Assessing modified olfactory training to prevent cognitive decline in MCI high-risk individuals: a multicentre randomised controlled trial protocol in Beijing tertiary hospitals

Chia-Yi Lin et al. BMJ Open. .

Abstract

Introduction: Mild cognitive impairment (MCI) presents a significant risk, with a 75-80% likelihood of progressing to dementia. Despite this high risk, there is currently no straightforward and effective treatment strategy to halt or reverse this progression. Olfactory dysfunction, in conjunction with subjective cognitive decline, offers a crucial opportunity for early intervention in older adults at risk of MCI. Conventional olfactory training (COT) has demonstrated potential in enhancing neuroplasticity, which is vital for cognitive health. Initial studies indicate that modified olfactory training (MOT) may yield superior outcomes compared to COT. Thus, this study aims to evaluate the efficacy of MOT in delaying and preventing the progression of MCI in high-risk individuals.

Methods and analysis: This randomised, controlled, multicentre, prospective and open-label trial will be conducted at Peking University Third Hospital and enrol 114 participants, who will be randomised 1:1:1 into three groups: MOT, COT and a control group. Standardised assessments will be conducted at baseline, 3 months, 6 months, 12 months and 24 months to measure cognitive and olfactory outcomes. The primary outcomes will be the change in Montreal Cognitive Assessment score, neuroimaging assessments and the Sniffin' Sticks test score. The secondary outcomes will include olfactory bulb volume and several neuroimaging tests.

Ethics and dissemination: This study protocol has been registered with ClinicalTrials.gov and has received approval from the Peking University Third Hospital Medical Science Research Ethics Committee (2023-347-01). The results will be disseminated through publication in scientific peer-reviewed journals.

Trial registration number: NCT06821828.

Keywords: Adult otolaryngology; Dementia; Parkinson-s disease; Physical Therapy Modalities.

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Conflict of interest statement

Competing interests: DW has the patent for this modified olfactory training device. The rest of the authors have no competing interests to declare. The funder did not influence the results/outcomes of the study despite author affiliations with the funder.

Figures

Figure 1
Figure 1. Description of modified olfactory training device. During exhalation, the soft palate completely seals off the nasal cavity (A). Exhaled air, now carrying odourants, enters the nose and exits through the opposite nasal passage. This creates a bidirectional airflow through both the left and right nasal cavities (B). This bidirectional delivery method significantly improved odour deposition in the olfactory region while significantly reducing deposition in the anterior nasal cavity.
Figure 2
Figure 2. Flow diagram illustrating the study design. COT, conventional olfactory training; MOT, modified olfactory training.
Figure 3
Figure 3. The modified olfactory training device (A) and conventional olfactory training device (B).
See this image and copyright information in PMC

References

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