NEFL and Lewy body dementia: First, we determined the values of plasma Aβ42/40 ratio, p‐tau‐181, NfL, and GFAP in the groups within the DLB continuum (iRBD, MCI‐LB, and DLB) and compared the levels of these plasma biomarkers at each stage of the DLB continuum with a group of clinically unimpaired controls.