Fig. 2.

DBS reduces [¹¹C]DPN binding in the PAG. (A–C) Brain-wide statistical parametric mapping (SPM) analysis across all patients showing changes in the total volume of distribution (V_T) on DBS. The SPM analysis shows the T-map (see colour bar) for a single cluster (threshold p<0.001 (uncorrected); 20 voxel cluster extent) of 31 voxels located in the dorsal PAG (p=0.003 uncorrected) shown superimposed on MNI standard brain (1 mm) in coronal, sagittal and transaxial sections (ipsi – side of DBS). The inset panels in B show an enlarged image of the cluster and the equivalent sagittal section around the PAG with the superimposed parametric image of the group mean [¹¹C]DPN V_T (DBS off condition) showing that the caudal PAG in the region of the cluster has the highest opioid binding. (D and E) For comparison the position of the DBS lead active cathode (centre of stimulation contact(s)) mapped into MNI space shown projected onto sagittal and horizontal sections. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)