[Contribution to anatomical and clinical studies of avoidance phenomena (author's transl)].

The authors report 5 cases of avoiding phenomenon of the hand from parietal lesions. Four of these patients were operated for intractable epilepsy, from a parietal cortectomy that implicated a certain amount of white matter. The avoiding phenomena observed are analyzed as elementary motor perturbations rather than a disturbance of motor comportment. The authors distinguish two types of avoiding phenomena: 1--Avoiding phenomenon of dystonic type occurs during any motor activity and persists during all its development. It is probably related to the removal of the cortex of the post-central gyrus and of the anterior part of the superior parietal lobule; 2--The initial avoiding phenomenon is brief and occurs only at the beginning of the movements which implicate solely the upper limb; it seems related to the removal of the internal part of the superior parietal lobule that corresponds approximately to areas 5 and 7 from Brodmann. Some hypotheses are discussed concerning the possible physio-pathological mechanisms of these disturbances.