Clustering mild cognitive impairment by mini-mental state examination

Area of Science:

• Neuroscience
• Gerontology
• Cognitive Psychology

Background:

• Mild cognitive impairment (MCI) is a transitional stage between normal aging and dementia.
• Accurate identification of MCI subtypes and their progression risk is crucial for timely intervention.
• The Mini-Mental State Examination (MMSE) is a widely used cognitive screening tool.

Purpose of the Study:

• To evaluate the Mini-Mental State Examination's (MMSE) ability to identify high-risk mild cognitive impairment (MCI) subtypes.
• To explore clustering of MMSE performance with demographic factors for predicting dementia conversion.
• To assess the utility of MMSE-based clustering as a screening tool for MCI.

Main Methods:

• Recruited 122 amnestic MCI-single domain (ASM), 303 amnestic MCI-multiple domains (AMM), and 94 non-amnestic MCI (NAM) participants.
• Employed two-step cluster and linear discriminant analyses to identify MMSE performance clusters based on age and education.
• Compared dementia conversion rates among identified clusters using odds ratios.

Main Results:

• Three distinct clusters emerged: Cluster 1 (205 AMM), Cluster 2 (61 NAM, 122 ASM), and Cluster 3 (33 NAM, 98 AMM).
• Cluster 3 exhibited significantly lower performance in orientation, registration, attention/calculation, language, and visuospatial skills compared to Clusters 1 and 2.
• Cluster 1 showed the highest conversion rate to dementia (OR = 2.940 vs. Cluster 2; OR = 2.271 vs. Cluster 3), particularly in delayed recall.
• Cluster 1 demonstrated the most significant conversion into dementia.

Conclusions:

• Clustering MMSE performance, alongside age and education, can effectively stratify MCI patients based on dementia risk.
• The MMSE, through performance clustering, shows promise as a screening and subtyping tool for MCI, especially when comprehensive neuropsychological testing is not feasible.
• This approach aids in identifying individuals with MCI who are at a higher risk of progressing to dementia.