NEFL and acute respiratory distress syndrome: Stratifying neuro-COVID and COVID groups into ARDS and non-ARDS groups, we observed that both neuro-COVID ARDS and COVID ARDS groups showed higher plasma NfL levels than the corresponding non-ARDS groups (neuro-COVID group, ARDS vs. non-ARDS: 90.3 [71.7–99.9] and 27.2 [19.8–29.9] pg/mL, respectively, p = 0.0357; COVID group, ARDS vs. non-ARDS: 28.6 [15.3–42.6] and 14.8 [9.2–27.4] pg/mL, respectively, p = 0.0041) (Figure 2G).