Accuracy of a Panel of 5 Cerebrospinal Fluid Biomarkers in the Differential Diagnosis of Patients With Dementia and/or Parkinsonian Disorders

Figure 1. Levels of cerebrospinal fluid (CSF) biomarkers in the different diagnostic groups. Box plots of α-synuclein (αSyn) (A), β-amyloid 1-42 (Aβ1-42) (B), total tau (T-tau) (C), phosphorylated tau (P-tau; P-tau₁₈₁ indicates that phosphorylation occurred at the 181 position; in this case, at threonine) (D), and neurofilament light chain (NF-L) (E) in CSF samples from controls (n = 107) and patients with Parkinson disease (PD) (n = 90), PD with dementia (PDD) (n = 33), dementia with Lewy bodies (DLB) (n = 70), Alzheimer disease (AD) (n = 48), progressive supranuclear palsy (PSP) (n = 45), multiple system atrophy (MSA) (n = 48), and corticobasal degeneration (CBD) (n = 12). The lower, upper, and middle lines of boxes correspond to the 25th percentile, 75th percentile, and median, respectively. The whiskers at the top and bottom extend from the 95th and 5th percentiles, respectively, and the circles represent outliers. The significant differences between groups according to the analysis of covariance models described in the “Results” section of the article are visualized in the figure.

Figure 2. Diagnostic accuracy of cerebrospinal fluid (CSF) biomarkers in patients with dementia or parkinsonism. Multivariate discriminant analysis (DA) was performed using the orthogonal projections to latent structures (OPLS) algorithm. Receiver operating characteristic curves were calculated for both OPLS-DA and for each analyte, including α-synuclein (αSyn), β-amyloid 1-42 (Aβ1-42), total tau (T-tau), phosphorylated tau (P-tau), and neurofilament light chain (NF-L). The areas under the curve (AUC) are given. A, Patients with Alzheimer disease (AD) (n = 48) were compared with patients with dementia with Lewy bodies (DLB) and those with Parkinson disease with dementia (PDD) (n = 103). B, Corresponding variable importance in projection (VIP) plot illustrates the relative contributions of T-tau, αSyn, P-tau, Aβ1-42, and NF-L to the separation between patients with AD vs patients with DLB or PDD. C, Patients with Parkinson disease (PD) (n = 90) were compared with patients with atypical parkinsonism, ie, progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and multiple system atrophy (MSA) (n = 105). D, Corresponding VIP plot illustrates the relative contributions of NF-L, P-tau, αSyn, T-tau, and Aβ1-42 to the separation between patients with PD vs patients with PSP, MSA, and CBD. Error bars represent the 95% CI.