Differential white matter connectivity in early mild cognitive impairment according to CSF biomarkers

Area of Science:

• Neuroscience
• Biomarkers
• Neuroimaging

Background:

• Mild cognitive impairment (MCI) is a heterogeneous condition.
• A subset of MCI patients progress to dementia.
• Cerebrospinal fluid (CSF) biomarkers can predict MCI conversion to dementia.

Purpose of the Study:

• To investigate white matter connectivity differences in early amnestic MCI (EMCI) subgroups.
• To analyze these differences based on CSF phosphorylated tau181p/amyloid beta1-42 ratios.
• To understand the relationship between CSF biomarkers and white matter integrity in EMCI.

Main Methods:

• Utilized data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database.
• Included 16 high-ratio EMCI, 25 low-ratio EMCI, and 20 normal control participants.
• Analyzed diffusion tensor imaging (DTI) data and CSF profiles.

Main Results:

• The low-ratio EMCI group exhibited increased radial diffusivity in the corpus callosum and longitudinal fasciculi compared to the high-ratio group.
• The low-ratio EMCI group showed significantly increased mean, axial, and radial diffusivity in widespread white matter regions versus normal controls.
• The high-ratio EMCI group did not differ from normal controls in white matter diffusivity.

Conclusions:

• Significant white matter connectivity differences exist between EMCI subgroups.
• These differences correlate with CSF phosphorylated tau181p/amyloid beta1-42 ratios.
• CSF biomarker ratios may differentiate EMCI progression pathways.