Cortical Myelin Density Patterns Across the Alzheimer's Disease Spectrum

These results corroborate a study reporting higher cortical myelin density in AD than CU obtained through T1/T2 ratio imaging (Pelkmans et al., 2019). Myelin appears most affected in deeper cortical layers through a process that progresses from MCI to AD. Potential explanations for this counter intuitive finding are compensatory remyelination observed in late stage AD (Bulk et al., 2018), disproportional atrophy of the superficial more stronger myelinated layers in AD thereby shifting the cortical depth lines potentially resulting in the group comparison of different cortical layers (Romito-DiGiacomo et al., 2007), and that the cortical maps obtained from the MP2RAGE images measure microstructure beyond myeloarchitecture.