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<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.