NEFL and primary central nervous system vasculitis: Similarly, the CSF NfL levels (Figure 2) were significantly higher in active PACNS patients (median: 4914.58 pg/mL; range: 372.17–35,170.34 pg/mL) compared to both the remission group (median: 301.19 pg/mL; range: 201.30–647.95 pg/mL; p = 0.004) and healthy controls (median: 262.83 pg/mL; range: 44.80–2507 pg/mL; p < 0.001).