[Participation of the brain stem in regulating postural synergy].

In 67 patients with local verified cerebral lesions, the activity of leg and trunk muscles was studied in involuntary movements of the arm in the usual vertical position. Forty-one of them showed some symptoms of primary or secondary dysfunctions of brain structures. On the basis of the present and previous studies, a conclusion was drawn that synergy associated with involuntary movements in the vertical position of man is impaired both in the local lesion of the additional motor portion and when damage to other portions of the frontal lobe is combined with an impairment of the brain stem. It is suggested that the trunk structures of the brain involved in the regulation of the posture synergy are located in pons varolii.