Plasma Neurofilament Light Chain as a Biomarker for Poor Outcome After Aneurysmal Subarachnoid Hemorrhage

Neurofilament light chain (NfL), a biomarker reflecting neuro-axonal damage, may be useful in improving clinical outcome prediction after aSAH. We explore the robust and additional value of NfL to neurological and radiological grading scales in predicting poor outcome after aSAH. In this prospective cohort study conducted in a single tertiary center, blood samples were collected of aSAH patients within 24 hours after ictus and before endovascular/surgical intervention. The primary endpoint was poor outcome at six months' follow-up. Receiver operating curves (ROC), area under the curve (AUC, 95% CI) and model-fit (Nagelkerke R2) were calculated for NfL, neurological grading scale (WFNS), modified Fisher, age and sex. A combined ROC and AUC were calculated for variables with an AUC≥0.70. A total of 66 (42%) had poor outcome. The AUC of NfL for poor outcome was 0.70 (0.62-0.78). Combining NfL and WFNS resulted in a slightly higher model-fit and not-significantly higher AUC for predicting poor outcome (R2 0.51; AUC 0.86, 0.80-0.92) compared to WFNS alone. When patients were stratified according to hemorrhage severity, median NfL [IQR] levels were significantly higher in poor grade (14 [7-32] pg/ml) than good grade patients (7 [5-14] pg/ml). Within poor grade patients, median NfL [IQR] levels were significantly higher in non-survivors (19 [11-36] pg/ml) than survivors (7 [6-13] pg/ml). In the entire aSAH cohort, plasma NfL has an acceptable predictive performance but does not improve clinical outcome prediction. However, NfL may have potential value in subgroups based on hemorrhage severity.