Voxel-based morphometry to detect brain atrophy in progressive mild cognitive impairment

Area of Science:

• Neuroimaging
• Neurology
• Gerontology

Background:

• Mild cognitive impairment (MCI) is a precursor to dementia, but predicting conversion remains challenging.
• Current diagnostic methods lack specificity for identifying individuals at high risk of dementia progression.
• Early identification of neurodegenerative changes is crucial for timely intervention.

Purpose of the Study:

• To investigate baseline brain structural changes using MRI in MCI subjects.
• To identify neuroimaging markers that predict conversion from MCI to dementia.
• To assess the extent and location of gray matter atrophy in MCI patients.

Main Methods:

• Longitudinal study of 56 MCI subjects and 22 controls, followed for an average of 37 months.
• Magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) used to analyze gray matter density at baseline.
• Neuropsychological tests and clinical assessments (CDR sum of boxes) used to track cognitive status and dementia conversion.

Main Results:

• MCI subjects showed reduced gray matter density in medial temporal, temporoparietal, and frontal cortical areas compared to controls.
• Progressive MCI subjects exhibited significant atrophy in the left temporoparietal cortex, posterior cingulate cortex, and precuneus compared to stable MCI.
• A trend for hippocampal atrophy was observed in progressive MCI subjects.
• CDR sum of boxes and delayed verbal recall were significant predictors of conversion to dementia.

Conclusions:

• Widespread cortical atrophy is detectable via MRI up to two and a half years before a clinical dementia diagnosis.
• Baseline MRI VBM can identify MCI individuals at higher risk of progressing to dementia.
• These findings highlight the potential of neuroimaging for early dementia prediction and intervention.