Hemichorea due to metastatic lesion in the subthalamic nucleus.

Abstract

Although the association of ballism and chorea with localized lesions in the subthalamic nucleus appears well established, 1-3 and experimental studies 4-7 have demonstrated that a similar form of dyskinesia can be produced by lesions in this nucleus in the rhesus monkey, relatively few cases of chorea or ballism due to metastatic lesions of the subthalamic nucleus have been reported. According to Whittier, 2 ballism most frequently occurs in hypertensive persons as a consequence of localized hemorrhage into the corpus Luysi (subthalamic nucleus). Only two reports 8,9 of ballism due to metastatic neoplasms (both primary in the breast) have been reported; this syndrome also has been reported in association with a discrete tubercle. 10 The current case was considered noteworthy not only because the dyskinesia appeared to be associated with a discrete metastasis but also because the chorea developed slowly, was somewhat intermittent in severity, and was exaggerated by the