Hemichorea–hemiballism syndrome following a thrombo-embolic striatal infarction

Abstract

A 70-year-old man was admitted to our emergency department for sudden onset of abnormal involuntary movements involving his upper and lower left limbs. Hemichoreal movements were restricted to his left limbs, associated with rare episodes of hemiballism (video). There were no cranial nerve alterations, no sensory loss or limb weakness. The patient reported mild hypertension under treatment. There was no history of diabetes mellitus or epilepsy, no prior exposure to neuroleptics or recent change in therapy. He denied any similar previous episode or family history of movement disorders. Chest radiography, electrocardiography, and laboratory tests including glucose, glycated hemoglobin, coagulation parameters, and immunoglobulin electrophoresis were normal. Brain non-contrast CT scan on admission showed no signs of acute ischemia (Fig. 1a). A supra-aortic-trunk Doppler sonography revealed an irregular surface plaque, partly ulcerated, on the origin of the right internal carotid artery with stenosis of about 90 %, confirmed at CT angiography (Fig. 1b). Brain MRI examination, performed 3 days after onset of symptoms, showed a linear altered signal area in the right basal ganglia, mostly in globus pallidus, on diffusion weighted imaging (DWI) sequences (Fig. 1c). The area was also visualized on the apparent diffusion coefficient (ADC) map (Fig. 1d), and on fluid attenuated inversion recovery (FLAIR) sequences (Fig. 1e). T1-weighted sequences of the basal ganglia were unremarkable (Fig. 1f). MRI angiography did not reveal abnormalities in the intracranial circulation. Our patient was thus diagnosed having an acute left hemichorea–hemiballism (HCHB) syndrome, caused by a carotid-originating embolic stroke, which affected the right lenticular nucleus. Medical treatments included immediate unfractionated heparin infusion, followed by warfarin and atorvastatin, while waiting for surgical treatment of the right carotid artery stenosis. The movement disorder was symptomatically controlled by oral administrations of clonazepam. 2 months later, he underwent surgical revascularization of the internal right carotid stenosis by thromboendarterectomy. 3-month follow-up revealed considerable symptom reduction with minimally disabling residual movements.