Multiple System Atrophy and Progressive Supranuclear Palsy. Diminished Striatal D2 Dopamine Receptor Activity Demonstrated by 123I-IBZM Single Photon Emission Computed Tomography - van Royen, EA; Verhoeff, NPLG; Speelman, JD; Wolters, EC; Kuiper, MA; Janssen, AGM (Arch Neurol, 1993)