Free water diffusion volume fraction from NODDI suggests inflammation may drive decreased memory performance in Subjective Cognitive Decline

Evidence suggests subjective cognitive decline (SCD) is an early risk factor for Alzheimer’s disease. We analyzed the associations between memory and diffusion microstructure in the lower cingulum white matter bundle in SCD with DTI and NODDI. Better memory performance was associated with decreased free water volume fraction (FWVF) in the SCD group but not the control group. To the best of our knowledge, this is the first study to find differences in the associations between NODDI FWVF and memory in SCD in the lower cingulum. This finding supports prior findings of increased neuroinflammation in the earliest stages of Alzheimer’s Disease.