Fig. 2: Kaplan–Meier curve and ROC curve of predictive models.

A Kaplan–Meier curve for a cumulative incidence of FOG during 4-year follow-up in the included PPMI dataset; B Adding the volume of VDC at year four (blue line) improved the performance of model 1 (red line) for the prediction of FOG conversion (AUC = 0.760 [0.641–0.879] VS. 0.701 [0.567–0.835]). AUC area under curve, FOG freezing of gait, PIGD postural instability gait difficulty, ROC receiver operating characteristic, VDC ventral diencephalon.