The addition of α-syn and NfL biomarkers did not improve the models’ ability to classify subjects as PD-NC and HC-NC, as the accuracy using DaT-SPECT was 95.83%, and the accuracy using DaT + α-syn or DaT + α-syn + NfL were both lower (80% in SVM and 90% in RF; 62.5% in SVM and 87.5% in RF, respectively). Here, NEFL is linked to Parkinson disease.