Hemiballismus following general anesthesia. A case report

Hemiballismus is characterized by the abrupt onset of violent proximal flinging movements, affecting the limbs, neck and trunk on one side of the body. It is caused by the lesion in the region of the contralateral subthalamic nucleus of the Luys. Usually it is a self-limiting disease, lasting 6-8 weeks. A 49-year-old man has been admitted to the hospital after flinging movements of his right arm and the right side of the trunk occurred. A few days earlier he had undergone general anesthesia prior to a dental procedure. There was trouble in waking the patient afterwards. The movements lasted a few days. MRI of the brain revealed ischemic lesions areas in T2-weighted images localized in the region of globus pallidus bilaterally. EEG was abnormal, and showed slowed background activity with slow waves in left temporal lobe. He was treated with haloperidol, clonazepam and vasoactive medications. In spite of administered treatment, hemiballic movements reappeared occasionally. Due to increased frequency of the movements the patient was hospitalized again two years later. The second MRI revealed changes described earlier and a new ischaemic focus in left parietal lobe. Continuation of treatment with haloperidol was administered.