NEFL and Menkes disease: When comparing NfL levels from MD and AD patients to the control group (mean 1,214.31 ± 448.1 pg/ml), we could find a significant increase in patients with AD (mean 1,859 ± 468.6 pg/ml; p < 0.001), MD (mean 2,041.77 ± 749.16 pg/ml; p < 0.01), LBD (mean 2,107 ± 289.9 pg/ml, p < 0.05), and PSP and CBD (mean 2,637.3 ± 710 pg/ml, p < 0.001) but not in patients with PD (mean 1,301 ± 144.3 pg/ml) (see Tables 1, 2 and Figure 1).