CSF neurofilament light chain and tau differentiate multiple system atrophy from Parkinsonʹs disease

Background In early disease stages it can be clinically difficult to differentiate idiopathic Parkinsonʹs disease (IPD) from patients with multiple system atrophy predominated by parkinsonism (MSA-P). Methods In CSF of 31 patients with IPD, 19 patients with MSA-P, we analyzed tau, neurofilament light chain (NFL) and heavy chain (NFHp35) and the noradrenergic metabolite 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG). Results CSF levels of NFL, NFHp35, and tau were significantly increased in MSA-P (all p < 0.0001), whereas, MHPG levels were significantly decreased in MSA-P (p < 0.0001). Optimal discriminative cut-off values for the differentiation between MSA-P and IPD were calculated resulting in high sensitivity (76–94%) and specificity (83–97%) levels. Multivariate logistic regression resulted in the combination of NFL and tau as independent contributors in differentiating between MSA-P and IPD. Discussion Higher CSF levels of axonal biomarkers could reflect advanced axonal degeneration in MSA-P. Differentiating MSA-P from IPD could be accurately possible with CSF analysis of a combination of axonal and neurotransmitter biomarkers.