CSF neurofilament light chain and tau differentiate multiple system atrophy from Parkinson's disease.

BACKGROUND: In early disease stages it can be clinically difficult to differentiate idiopathic Parkinson's 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