Participation of ipsilateral hemisphere lesions in the pathology of hemichorea and hemiballismus

PREVIOUS NEUROLOGIC AND ANATOMIC investigations of the brains of individuals suffering from hemiballismus or hemichorea devoted their primary attention to lesions of the hemisphere contralateral to the affected side of the body. However, certain reports have appeared in the literature of cases in which the syndrome seemed to be caused by lesions affecting structures of the homolateral hemisphere. The problem raised by these observations has been discussed by several authors, but no conclusions have been reached because the lesions which could have accounted for the syndrome were usually multiple. Furthermore, the temporal sequence of onset of abnormal motion and production of each one of the lesions could not be established unequivocally in most of the cases. During our observations of the immediate postoperative neurologic status of patients with Parkinson's disease who had undergone chemopallidectomy or chemothalamotomy for the relief of tremor and rigidity,' we recorded homolaterally released hemiballistic and hemochoreic manifestations in some patients. One of the first descriptions of a case in which a lesion in one hemisphere manifested itself as a clinical syndrome of choreiform motility affecting the homolateral limbs was reported by Noehte.? Since this report did not contain n microscopic study of the brain, it is reasonable to doubt whether the opposite hemisphere was really free of any pathology. ConosS described another case involving pathology of the hemisphere homolateral to the side of the body affected by the syndrome.