NEFL and multiple system atrophy: The median concentration of NfL was significantly higher in MSA patients compared to HC for both the CSF (4329 pg/ml, IQR 2577–5862 versus 560 pg/ml, IQR 420–855, P < 0.001) and for plasma (39.9 pg/ml, IQR 27–48 versus 9.1 pg/ml, IQR 8.7–9.8, P < 0.001).