title: Confusion, Faciobrachial Dystonic Seizures, and Critical Hyponatremia in a Patient with Voltage-Gated Potassium Channel Encephalitis.
abstract: Autoimmune limbic encephalitis is a rare cause of encephalitic disease. It is associated with various target antigens and is difficult to diagnose, and experience with its treatment is limited. This case report describes a 69-year-old man, who presented with life-threatening hyponatremia and confusion, following several months of gradually worsening faciobrachial dystonic seizures. Faciobrachial dystonic seizures are a well-described feature classically observed in voltage-gated potassium channel autoimmune encephalitis. The presence of chronic hyponatremia without cognitive dysfunction, eventually culminating in an acute episode of encephalopathy and severe hyponatremia, is a pattern of natural history not previously documented in this condition.
authors.affiliation: Department of Internal Medicine, Redcliffe Hospital, Redcliffe, Queensland, Australia.
authors.forename: Julian
authors.initials: J
authors.lastname: Yaxley
keywords: Dystonia; Encephalitis; Hyponatremia; Seizure