Wilson's disease is a rare autosomal recessive disorder characterized by impaired copper transport and accumulation of copper in various organs. While hepatic involvement is common, up to 40% of patients may present with neurologic symptoms, including movement disorders. Chorea is an uncommon presentation of Wilson’s disease, with unilateral chorea being exceedingly rare.

A 74-year-old woman with a history of Wilson’s disease presented with three weeks of progressive left-sided choreiform movements. She had been diagnosed with Wilson’s disease at age 32, with initial manifestations including Kayser–Fleischer rings, tremors, elbow flapping, and liver involvement. She had been on trientine and zinc for several years, but treatment had lapsed before presentation. The tremors, which had previously resolved, recurred three weeks before presentation. Brain MRI demonstrated mild T2 hyperintensity in the right basal ganglia and midbrain tegmentum, consistent with Wilson’s disease. She did not have hyperglycemia prior to symptom onset (HbA1c 5.1). Liver function tests were normal. Autoimmune and paraneoplastic movement disorder panels were negative, including CRMP-5. Serum copper measured a few days prior was markedly elevated at 2,203 µg/L. The 24-hour urine copper level was elevated to 326 µg on subsequent evaluation. The patient was restarted on her maintenance trientine regimen of 250 mg three times daily and zinc, with marked improvement of chorea. Trials of clonazepam, deutetrabenazine, and valbenazine produced no significant benefit. The patient’s improvement with trientine strongly suggests that the unilateral symptoms were attributable to Wilson’s disease rather than an alternative etiology. 

This case represents one of the first reported instances of initial unilateral neurological manifestations of Wilson’s disease accompanied by contralateral MRI changes. It underscores the importance of recognizing atypical neurological presentations of Wilson’s disease.