NEFL and Parkinson disease: Similar findings were found in the Lund cohort where the concentrations of plasma NfL were significantly increased in all disorders when compared to the CU Aβ−, CU Aβ+ , SCD Aβ−, SCD Aβ+ groups (P < 0.0001), and MCI groups (P = 0.001), with nonsignificant differences in PD and EOAD.