Chorea can be part of a wide spectrum of autoimmune, paraneoplastic, or para-infectious conditions. Antibodies against leucine-rich-glioma-inactivated-1 (LGI1), component of voltage-gated potassium channels (VGKC), typically produce a syndrome of autoimmune encephalitis (AE), hyponatremia, and facio-brachial dystonic seizures (FBDS). Movement disorders related to LGI-1 can include generalized chorea, typically occurring in the context of the above-cited syndromes. Isolated asymmetric chorea as a presenting feature is rare. We describe a patient with LGI1-associated-AE presenting with subacute asymmetric chorea. 

There are only a few case reports of chorea in LGI-1-autoimmune encephalitis, and typically in association with other classic features. The one other report we found of isolated LGI-1 chorea was by Ramdhani and Frucht (2014). Like theirs, our patient had isolated generalized chorea and mild hyponatremia, without classic features of AE. However, in our patient, the chorea was markedly asymmetric with occasional bilateral involvement. He continued to perform all activities of daily living independently. As is typical in LGI-1-AE, he did not have any underlying malignancy. He had a robust response to steroids and immunotherapy, with resolution of symptoms.