Fig. 2

Hypometabolic and hypermetabolic clusters in PwPD relative to healthy controls based on metabolic time series comparison. SPM result of HC > PD visualised on MNI standard template. Sagittal, coronal and axial view of regions of hypometabolic (a-c) or hypermetabolic (d) activity obtained by voxel-wise group comparison of [¹⁸F]-FDG fPET scans from 13 healthy controls and 14 PD patients (P < 0.05 after FWE cluster level correction, extent threshold > 20 voxels). (e-f) Extracted individual and group mean time courses per cluster (MNI peak coordinates). (g) Regression plots for subcortical hypometabolism vs. cortical hypermetabolism (filled dots represent mean uptake per region). (h) Receiver operating characteristic curve illustrating the trade-off between sensitivity and specificity for group classification based on all clusters, hypometabolic or hypermetabolic clusters respectively. All images are shown in neurological display. PD = Parkinson’s disease, HC = healthy controls, SN = substantia nigra.