Fig. 1. Overlap and correlations between abnormal biomarker results in IRBD.

Schematic representation of concomitant pathological profiles (A) and correlations among biomarkers (B). Biomarker positivity was defined as follows: A+ = Aβ positivity (Aβ₄₂/Aβ₄₀ < 0.65), T+ = tau positivity (p-tau181 > 60 pg/ml), N+ = neurodegeneration positivity (t-tau > 450 pg/ml), AS+ = misfolded α-synuclein positivity by SAA. For correlations, t-tau, p-tau, and NfL values were log-transformed. Pearson’s r values are shown. AS misfolded α-synuclein, AS_Imax the maximum peak of SAA fluorescence curve, Aβ₄₂ 42 amino acid isoform of amyloid-beta, Aβ₄₀ 40 amino acid isoform of amyloid-beta, p-tau tau protein phosphorylated at residue 181, NfL neurofilament light chain, t-tau total tau protein, SAA seed amplification assay.