[Effect of dentatotomy on muscle tonus in infantile cerebral palsy]. / Vliianie dentatotomii na myshechnyi tonus pri detskom tserebral'nom paraliche.

The article deals with the results of the quantitative study of the muscular tonus in patients with infantile cerebral paralysis by the method of passive sinusoid movements of the arm at the elbow joint at various rates, with a period of T = Is to T = 200s and its assessment by the value of the mechanical resistance of the extremity in the region of high (T = I--4s) and low rates (T = 50s). The spectromechanomyographic method of examination revealed two components in the muscular tonus: an increase in the region of high rates, which were identify as the spastic component of the muscular tonus, and an increase in the region of low rates, which is identified with the rigid component of the muscular tonus. Operative destruction of the cerebellar dentate nuclei in patients with infantile cerebral paralysis naturally reduces this spastic component, but hardly changes the rigid component. One of the factors causing changes in the shape and amplitude of choreothetoid hyperkinesia in patients with infantile cerebral paralysis may evidently be the redistribution of the tonus in different muscular groups and changes in the correlations between its spastic and rigid components.

[Clinical physiological effects of electrostimulation and destruction of the ventrolateral portions of the cerebellar dentate nuclei in different forms of motor pathology]. / Kliniko-fiziologicheskie éffekty élektrostimuliatsii i destruktsii ventro-lateral'nykh otdelov zubchatykh iader mozzhechka pri razlichnykh formakh dvigatel'noi patologii.

The effect of electrostimulation and destruction of the ventrolateral parts of the cerebellar dentate nuclei is described on the basis of 27 dentotomies performed on patients with different forms of motor pathology. The dento-cortical connections were studied by advancing electrodes to the cerebral and cerebellar cortex through trephination openings made in the postero-frontal-parasagittal area for ventriculography and in the occipital area for the insertion of a stereotaxic cannula. It was found that the principal test for operative identification of the ventro-oral parts of the dentate nucleus in electrostimulation are motor reactions and changes in the muscular tonus in the homolateral limbs and reactions of the cortex of the central and precentral areas of the cerebral hemispheres revealed by electrocorticography. The main clinical effect produced by the destruction of these parts of the dentate nuclei is diminution of the spastic component of muscular hypertonus; hardly any effect is caused on the rigidity component. Redistribution of muscular tonus is among the factors inducing postoperative changes in hyperkinesia.