Constantin von Economo's contribution to the understanding of movement disorders.

Constantin von Economo's (CvE) main scientific achievements were his studies on the cytoarchitectonics of the cerebral cortex, sleep, and encephalitis lethargica (EL). He found a close relationship between motor symptoms and psychiatric and behavioral disorders in EL and postencephalitic Parkinsonism and identified the underlying neuropathology in the diencephalon and the brainstem. In agreement with Tretiakoff's findings in Parkinson's disease, CvE related postencephalitic Parkinsonism to neuronal loss in the substantia nigra. Several of CvE's early, less well-known publications also deal with the basal ganglia and movement disorders. He demonstrated in rabbits that the substantia nigra modulates automatization, coordination, and succession of masticatory movements and swallowing. In a study on the effects of experimental lesions of the cerebral peduncle in cats and monkeys, CvE hypothesized a corticotegmental pathway that maintains motor functions after pyramidal tract lesions. Recent studies have identified this pathway, which ends in the pedunculopontine nucleus. In a study on posthemiplegic chorea, CvE discussed various pathophysiological hypotheses that partly resemble modern concepts of chorea. In a clinicopathological study on Wilson's disease, CvE traced the striofugal fibers and visualized the basal ganglia outflow pathways. CvE was an outstanding multidisciplinary movement disorder specialist who contributed substantially to modern basal ganglia research.