Fig. 2

Thalamic atrophy in Parkinson’s disease patients. Statistical parametric maps of a PD patients with mild to moderate vs. severe non-motor symptoms; b PD patients with sleep/fatigue disturbances vs. those without sleep/fatigue; c PD patients with gastrointestinal tract dysfunction vs. those without gastrointestinal tract dysfunction. Yellow–red areas represent voxel clusters of significant volume loss. The colour stripe indicates z-values. MNI co-ordinates: a x = 3.85, y = − 12.23, z = 3.37; b x = 11.55, y = − 11.46, z = 4.90; c x = 9.24, y = − 26.85, z = 7.22