Ballism not related to vascular disease: A report of 16 patients and review of the literature.

Sixteen patients with ballism not related to vascular disease are reported. Ballism was caused by subthalamic metastases and cerebral tumours in four patients, lesions after functional stereotaxy in three, presumed neurodegenerative disease in two, and by an ipsilateral intraventricular cyst after resection of a meningioma, cerebral toxoplasmosis with AIDS, severe head trauma and sepsis, late recurrence of rheumatic fever, meningoencephalitis, perinatal hypoxia, and conversion syndrome in one, respectively. Two patients had bilateral ballism, 11 had hemiballism, and three had monoballism. Involvement of the contralateral subthalamic nucleus was found in 10/13 patients with symptomatic unilateral ballism. One patient with presumed neurodegenerative disease had bilateral alterations of caudate and putamen on MR. The effect of different treatment strategies was evaluated. Treatment was directed to the underlying disease and/ or to the movement disorder. Response to pharmacotherapy was poor except in one patient. Five patients underwent various neurosurgical interventions. Functional stereotactic operations were performed in eight patients. Lesions were placed in the contralateral ventrolateral thalamus and the zona incerta, the internal pallidum, and in the zona incerta and the pulvinar thalami. Four out of eight patients had complete sustained relief of hemiballism after the operation. No patient was lost to follow-up, which ranged from 3 months to 27 years. After various therapeutic strategies ballism was no longer present in 10 patients and had improved in three, while another three patients did not benefit from therapy. Review of the literature illustrates the shift of aetiologic factors over decades underlying this rare symptom. A multidisciplinary approach should be considered in these patients to alleviate the severe and disabling movement disorder.