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?
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
114
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.
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.
Dawei Wu
Beijing, Beijing Municipality, China
Montreal Cognitive Assessment (MoCA) score
The MoCA score will be used to evaluate cognitive function across several domains including memory, attention, language, and orientation.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Biomarkers of cognition (Blood/CSF)
This measure includes plasma and CSF levels of UGOT p-tau217, CSF Aβ42, p-tau181, total tau, and amyloid β 42 to total tau ratios. These biomarkers will help in assessing the biochemical progression of cognitive impairment.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Neuroimaging assessments
This includes MRI scans focusing on temporal lobes and other brain regions, and amyloid PET scans to detect amyloid plaques. These imaging techniques will provide insights into structural and functional changes in the brain associated with cognitive decline.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
The Sniffin' Sticks test
a clinically significant olfactory improvement as measured by Sniffin' Sticks threshold, discrimination, and identification（TDI)( more than 6 scores)
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Auditory Verbal Learning Test (AVLT)
Evaluates immediate memory recall, learning rate, and delayed recall, providing insights into verbal learning and memory.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Digit Span Test (DST)
Assesses attention and working memory through forward and backward number recall tasks.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
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Trail Making Test (TMT)
Measures visual attention and task switching by requiring participants to connect a sequence of numbers and letters as quickly as possible.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Clock Drawing Test (CDT)
Used to assess visual-spatial abilities and executive function by having participants draw a clock showing a specific time.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Boston Naming Test (BNT)
Measures language function, specifically object naming ability, which is crucial for everyday communication.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Verbal Fluency Test (VFT)
Assesses cognitive flexibility and semantic memory by requiring participants to generate as many words as possible from a category in a limited time.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Activities of Daily Living Scale (ADL)
Evaluates the participant's ability to perform everyday tasks independently, reflecting functional status.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Instrumental Activities of Daily Living (IADL)
Assesses more complex daily living skills critical for independent living, such as managing finances and medication.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Neuropsychiatric Inventory (NPI)
Measures behavioral changes including depression, anxiety, aggression, and apathy among others, providing a comprehensive overview of psychological status.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Hamilton Anxiety Scale (HAMA)
Assesses the severity of anxiety symptoms, which can impact cognitive and daily functioning.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Hamilton Depression Scale (HAMD)
Used to quantify the level of depressive symptoms, aiding in the assessment of mood disorders which can co-occur with cognitive decline.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24
Olfactory bulb volume
Measurement of the olfactory bulb volume using MRI to assess changes or improvements in olfactory structures which might correlate with training efficacy.
Time frame: Baseline,Month 3,Month 6,Month 12,Month 24