Classifying anatomical subtypes of subjective memory impairment

Area of Science:

• Neurology
• Neuroimaging
• Cognitive Science

Background:

• Subjective memory impairment (SMI) represents a preclinical stage of cognitive decline.
• Understanding the heterogeneity of SMI is crucial for early diagnosis and intervention.
• Cortical thickness patterns may reveal distinct subtypes within the SMI population.

Purpose of the Study:

• To categorize individuals with subjective memory impairment (SMI) based on cortical thickness patterns.
• To develop classification models for identifying distinct SMI subtypes.
• To explore the clinical characteristics associated with each identified subtype.

Main Methods:

• Recruited 613 SMI individuals and 613 age/gender-matched controls.
• Employed hierarchical agglomerative cluster analysis to identify atrophy patterns.
• Utilized logistic regression models combining clinical factors for subtype classification.

Main Results:

• Identified three SMI subtypes: temporal atrophy (12.9%), minimal atrophy (52.4%), and diffuse atrophy (34.6%).
• Temporal atrophy subtype showed Alzheimer's disease-like atrophy, older age, vascular risk factors, and lower neuropsychological scores (73.2% classification accuracy).
• Minimal atrophy subtype (non-neurodegenerative) was associated with younger age, female sex, and depression (76.0% classification accuracy).

Conclusions:

• Subjective memory impairment can be categorized into three distinct anatomical subtypes with unique clinical profiles.
• These subtypes and their classification models may assist clinicians in patient management and stratify participants for clinical trials.