A PET study of subthalamic nucleus stimulation in Parkinson´s disease: Enhanced movement related activity of motor association cortex and decreased motor cortex resting activity - Ceballos-Baumann, AO; Boecker, H; Bartenstein, P; von Falkenhayn, I; Riescher, H; Conrad, B; Moringlane, JR; Pinter, M; Alesch, F (Arch Neurol, 1999)