CSF and Circulating NFL as Biomarkers for the Discrimination of Parkinson Disease From Atypical Parkinsonian Syndromes: Meta-analysis

Abstract: Purpose of review: To evaluate whether CSF and circulating neurofilament light chain (NFL), a marker of axonal damage, could discriminate Parkinson’s disease (PD) from atypical parkinsonian syndromes (APS). Recent findings: MEDLINE and SCOPUS were systematically searched, and fifteen studies were included (1035 PD patients,930 APS patients). CSF and circulating NFL levels were 1.26 and 1.53 standard deviations higher in APS compared to PD patients respectively [g=1.26 (95% CI 0.99-1.53);12 studies, 880 PD patients, 847 APS patients, g=1.53 (1.15-1.91);4 studies, 307 PD patients, 197 APS patients. Pooled areas under the curve were 0.941 (0.916-0.965) and 0.874 (0.802-0.946) for CSF and circulating NFL, corresponding to average sensitivities of 86% (79-90%) and 91% (86-95%), and specificity of 88% (82-92%) and 76% (62-85%), respectively. Summary: These results strongly support the high diagnostic accuracy of both CSF and circulating NFL in differentiating PD from APS, highlighting their usefulness as promising biomarkers.