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Not yet recruiting NCT06821828

The Efficacy of Modified Olfactory Training for MCI High-Risk Individuals

No phase Interventional Subjective Cognitive Decline (SCD) Olfactory Dysfunction Mild Cognitive Impairment (MCI) ELDERLY PEOPLE

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Modified olfactory training device, Conventional olfactory training device.
Who it may be relevant to
Registry conditions: Subjective Cognitive Decline (SCD), Olfactory Dysfunction, Mild Cognitive Impairment (MCI), ELDERLY PEOPLE. Basic parameters: 60 years — 90 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
China
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Official title

Assessing Modified Olfactory Training to Prevent Cognitive Decline in MCI High-Risk Individuals: A Randomized Controlled Trial Protocol

Overview

The goal of this clinical trial is to validate the effectiveness of the modified olfactory training device, the main questions it aims to answer are: Is it possible that the device can delay the progression of MCI in older adults? Compared to the conventional device, how efficient is the modified olfactory training device for improving cognitive function?

Detailed description

Mild Cognitive Impairment (MCI) represents an intermediary stage between normal aging and dementia, with a significant proportion of cases progressing to dementia. No simple and effective therapeutic strategies are available to halt or reverse this progression. Olfactory dysfunction, a common early clinical manifestation of neurodegenerative diseases such as Alzheimer's Disease (AD), often precedes cognitive decline. Subjective Cognitive Decline (SCD) is increasingly recognized as a prodromal stage of MCI and dementia, which, together with olfactory dysfunction, provides a critical window for early intervention.

Conventional olfactory training (COT) has been shown to improve olfactory function, cognitive abilities, and brain connectivity in healthy elderly individuals, suggesting its potential to enhance neuroplasticity. Preliminary studies indicate that modified olfactory training (MOT) may yield superior outcomes compared to COT, with higher rates of olfactory recovery and improved deposition in the olfactory fissure. However, the efficacy of MOT in delaying or preventing the progression of olfactory dysfunction to MCI remains unclear.

In this study, the investigators planned to recruit 114 patients and divided them into three groups for control group and olfactory training with conventional and modified devices, and validate the effectiveness of the modified device based on changes in cognitive function and the comparison of the outcomes of the three groups.

Interventions

  • Combination product Modified olfactory training device
    Participants will use a modified olfactory training device based on expiratory pressure. The advantages of the improved device are as follows: bi-directional airflow, positive pressure and the function of voice prompts and automatic counting.
  • Combination product Conventional olfactory training device
    This device involves four brown glass jars (total volume 5 mL) with one of the four odors in each (1mL each, soaked in cotton pads to prevent spilling). The following odors were used: phenyl ethyl alcohol (PEA): rose, menthol: mint, citronellal: lemon, and eugenol: cloves. All jars were labeled with the odor name.

Primary outcome measures

  • Montreal Cognitive Assessment (MoCA) score [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Biomarkers of cognition (Blood/CSF) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Neuroimaging assessments [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • The Sniffin' Sticks test [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
Secondary outcome measures (12)
  • Auditory Verbal Learning Test (AVLT) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Digit Span Test (DST) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Trail Making Test (TMT) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Clock Drawing Test (CDT) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Boston Naming Test (BNT) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Verbal Fluency Test (VFT) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Activities of Daily Living Scale (ADL) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Instrumental Activities of Daily Living (IADL) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Neuropsychiatric Inventory (NPI) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Hamilton Anxiety Scale (HAMA) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Hamilton Depression Scale (HAMD) [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]
  • Olfactory bulb volume [Time frame: Baseline,Month 3,Month 6,Month 12,Month 24]

Eligibility criteria

Inclusion criteria

  • Age and Gender: Individuals aged 60-80 years, regardless of gender.
  • Diagnosis of Idiopathic Olfactory Dysfunction: overall TDI score below 30.75 points using the Sniffin' Sticks test. Without olfactory impairment due to traumatic, sinusitis-related, congenital, toxic/drug-induced causes, post-operative conditions, tumors, or post-upper respiratory infections.
  • Diagnosis of Subjective Cognitive Decline: Montreal Cognitive Assessment (MoCA) score >24 for middle school level and above, >19 for elementary school level, and >13 for illiterate individuals. Amyloid β (Aβ) deposition in the brain (defined as Aβ42 < 550 ∼ 813 pg/ml)， the higher Formula of Hulstaert (defined as \[(Aβ42/(240 + 1.18 × tau) ≤1\]）, and hippocampus atrophy.
  • Consent: Willingness to sign an informed consent form.

Exclusion criteria

  • Comorbid Chronic Diseases or Severe Concurrent Illnesses: Individuals with conditions such as hypertension, diabetes, bronchopneumonia, malignant tumors， or chronic obstructive pulmonary disease.

4\. Recent Medication Use: Exclusion of participants who have taken corticosteroids, antimicrobials, leukotriene antagonists, or antihistamines within the last four weeks.

5\. Inability to Comply with Study Requirements: Based on the researcher's judgment, individuals who are unable to tolerate olfactory function tests and treatment， complete the study or comply with its requirements due to memory or behavioral abnormalities, depression, severe alcohol consumption, or previous non-compliance.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation
Randomized
Model
Parallel assignment
Masking
Triple blind
Primary purpose
Prevention

Study locations

China · 1 center
  • Dawei Wu — Beijing

Publications

  • Lin CY, Tan Y, Zhao D, Wu D. Assessing modified olfactory training to prevent cognitive decline in MCI high-risk individuals: a multicentre randomised controlled trial protocol in Beijing tertiary hospitals. BMJ Open. 2025 Aug 13;15(8):e100880. doi: 10.1136/bmjopen-2025-100880. PMID 40812823

Identifiers

NCT: NCT06821828 · 9059101

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗