title: [Impairment of the accuracy of tracking movements in lesions of the cerebellum and pyramidal system in man].
abstract: Kinematic and electromyographic characteristics of step-tracking movements performed with and without visual guidance have been studied in 3 groups of patients suffering from hereditary lesions of intermedial and lateral systems of the cerebellum and pyramidal tract. Lesions of the intermedial cerebellum not changing parameters of the first preprogrammed component altered deeply the maintenance phase that was performed as large oscillations around a required level. Lesions of the lateral cerebellum, on the contrary, were followed by inability to control accurately the amplitude of steps which were performed with a constant hypermetric error; the maintenance phase of movement was not disturbed in this group. In patients suffering from pyramidal lesions the initial rapid limb position adjustment was replaced by slow approximating tracking; the maintenance component of the movement was performed with fluctuations and constant drift towards the ground. It is concluded that whereas the lateral cerebellar system is involved in central motor program mechanisms, the intermedial cerebellum is essential for accurate postural maintenance.
mesh_terms: D000161:Acoustic Stimulation; D002493:Central Nervous System Diseases / Q000150:complications*; D002526:Cerebellar Diseases / Q000150:complications; D004576:Electromyography; D005246:Feedback; D005621:Friedreich Ataxia / Q000150:complications; D006801:Humans; D011596:Psychomotor Disorders / Q000209:etiology*; D011712:Pyramidal Tracts; D011930:Reaction Time / Q000502:physiology; D013577:Syndrome
vernacular_title: Narusheniia tochnostnykh slediashchikh dvizheniĭ pri porazhenii mozzhechka i piramidnoĭ sistemy u cheloveka.