Comparison of motor, cognitive, and behavioral features in progressive supranuclear palsy and Parkinson's disease.

Major clinical features and global measures were systematically evaluated and compared in progressive supranuclear palsy (PSP) and Parkinson's disease (PD). In addition to gaze palsy and early postural instability in PSP, absence of levodopa-induced dyskinesia, frontalis muscle overactivity, primitive reflexes, visuospatial impairment, and substantial frontal behavioral disturbances differentiated almost all patients with this disorder from PD. For PSP, behavioral changes related to severity of general disability, thereby challenging previous models of relationships between behavior, motor, and cognitive disturbance for this disorder.