NEFL and mild neurocognitive disorder: The results confirmed that the eGFR was normal in all tested MND patients and did not significantly influence the plasma levels of TDP-43 (Pearson’s r = − 0.173, p = 0.207) (Fig. 6B), nor those of NfL (Pearson’s r = 0.018, p = 0.895) (Fig. 6E).