Multifocal myoclonus as a heralding manifestation of Wilson disease.

Wilson disease (WD) is one of the few curable movement disorders that manifests with varied presentations so that WD needs to be considered in any patient with a movement disorder under the age of 50 years. Although WD is one of the causes of myoclonus, it is rarely seen in WD and usually as an associated finding. We report a case of an adolescent female patient of WD who presented with cortical multifocal myoclonus of 6-month duration with later development of generalized dystonia, extrapyramidal syndrome, and cognitive decline. Kayser-Fleischer ring was present on slit lamp examination. Serum copper, urine copper, serum ceruloplasmin, and magnetic resonance imaging brain were consistent with the diagnosis of WD. Copper chelation was started along with other symptomatic treatments and diet modifications. Myoclonus had resolved by 3-month follow-up with the improvement of other symptoms. This case report emphasizes that myoclonus can be the main and presenting feature of WD.