The plasma NFL level was significantly higher in the disease groups of PSP (68.8 ± 22.0 pg/mL, p = 0.003), CBS (58.6 ± 32.0 pg/mL, p = 0.003) and FTD (52.40 ± 21.80 pg/mL, p = 0.02) compared to those in the control group (9.82 ± 5.30 pg/mL). This evidence concerns the gene CBS and frontotemporal dementia.