title: A case of hyperkinetic movement disorder associated with LGI1 antibodies.
abstract: Encephalitis associated with leucine-rich glioma inactivated 1 (LGI1) antibodies is often encountered in elderly male patients and may infrequently present with isolated syndromes. A 6-year-old boy was admitted with acute onset severe oral and facial stereotypic and choreiform movements. On his neurologic examination, he had repetitive and rhythmic movements in orolingual muscles including tongue protrusion, limb chorea and minimal facial stereotypic movements. Anti-streptolysin O (ASO) titers were found severely elevated in several measurements. Well-characterized antibodies against ion channels and synapse proteins were negative whereas LGI1 antibody was positive in both serum and CSF. Marked clinical improvement was observed after immunotherapy. Here, we present the first pediatric case with LGI1 antibody associated hyperkinetic movement disorders and emphasize the importance of investigating neuronal autoantibodies in patients with isolated and treatment resistant movement disorders.
authors.affiliation: Division of Neurology, Institute of Neurological Sciences, Uludag University Faculty of Medicine, Bursa, Turkey. drerdem@yahoo.com.
authors.forename: Sevda
authors.initials: S
authors.lastname: Erer Özbek
authors.forename: Zuhal
authors.initials: Z
authors.lastname: Yapıcı
authors.forename: Erdem
authors.initials: E
authors.lastname: Tüzün
authors.forename: Murat
authors.initials: M
authors.lastname: Giriş
authors.forename: Selcen
authors.initials: S
authors.lastname: Duran
authors.forename: Özlem
authors.initials: Ö
authors.lastname: Taşkapılıoğlu
authors.forename: Mehmet
authors.initials: M
authors.lastname: Okan
mesh_terms: D001323:Autoantibodies / Q000097:blood; D002648:Child; D003937:Diagnosis, Differential; D006801:Humans; D006948:Hyperkinesis / Q000175:diagnosis / Q000276:immunology*; D047908:Intracellular Signaling Peptides and Proteins; D007930:Leucine; D008297:Male; D011506:Proteins / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D047908:Intracellular Signaling Peptides and Proteins; C116499:LGI1 protein, human; D011506:Proteins; D007930:Leucine