Mapping gray matter loss with voxel-based morphometry in mild cognitive impairment

Area of Science:

• Neuroimaging
• Neurology
• Cognitive Neuroscience

Background:

• Mild cognitive impairment (MCI) is characterized by progressive isolated episodic memory decline.
• Understanding the neuroanatomical correlates of MCI is crucial for early diagnosis and intervention.
• Previous MRI studies have used region-of-interest approaches to investigate brain structure in MCI.

Purpose of the Study:

• To objectively map gray matter loss in patients with amnestic mild cognitive impairment (aMCI).
• To compare the pattern of gray matter loss in aMCI with healthy controls and mild Alzheimer's disease (AD).
• To expand upon previous findings using a comprehensive voxel-based morphometry approach.

Main Methods:

• Voxel-based morphometry (VBM) was employed to analyze structural MRI scans.
• 22 patients with aMCI were compared with 22 age-matched healthy controls.
• aMCI patients were also compared with 16 age-matched patients with mild AD.

Main Results:

• Patients with aMCI exhibited significant gray matter loss compared to controls.
• Gray matter loss in aMCI predominantly affected the hippocampal region and cingulate gyri, extending into the temporal neocortex.
• Gray matter density was significantly preserved in the posterior association cortex of aMCI patients compared to those with mild AD.

Conclusions:

• The observed pattern of gray matter loss in aMCI is consistent with but expands upon prior MRI studies.
• This pattern aligns with the known progression of neurofibrillary tangles in aging and Alzheimer's disease.
• VBM provides a comprehensive map of structural changes in aMCI, aiding in differential diagnosis from early AD.