NEFL and Parkinson disease: We had shown previously that blood NfL differentiates MSA-C from non-MSA sporadic adult-onset ataxia with an area under the curve of 0.74 (95% CI 0.59–0.89), P = 0.004.12 Similarly, blood NfL can be used to distinguish between patients with Parkinson’s disease and patients with MSA with high diagnostic accuracy (areas under the curve 0.81–0.91) with similar performance for both blood and CSF NfL.9