[Hemiballism caused by metastasis to Luys' body].

A 66 year-old man suddenly developed a left-sided hemiballism. CT scan revealed 3 metastases, one of them in the area of the right subthalamic nucleus (corpus Luysii). A primary lung tumor was suspected. Haloperidol and tiapride were unsuccessful to control the hemiballism. The patient died 5 months later. Pathological examination confirmed the diagnosis. The pathophysiology of this case is discussed with regard to the pathological findings. Hemiballism secondary to a metastasis is rare, 9 cases have been reported during the past 65 years. Vascular lesions are the usual cause (75 per cent); on rare occasions degenerative disorders (14 per cent), destructive (tumors: 10 per cent or surgical lesions: 0,3-9 per cent) can also result in hemiballism.