title: Natural course of LGI1 encephalitis: 3-5 years of follow-up without immunotherapy.
abstract: Antibodies against LGI1 (leucin-rich glioma-inactivated 1 protein) are associated with limbic encephalitis (LE), which is characterized by a favorable outcome following immunotherapy. Here, we present two cases, where antibodies against LGI1 were detected in the sera 36 and 53 months after acute LE, respectively, and none of the patients received immunotherapy. LE showed characteristics of LGI1 encephalitis in both cases, including low sodium content in the sera; disorientation, hallucination, short-term memory loss; and epileptic seizures. One patient had faciobrachial tonic seizures. MRI indicated bilateral inflammation of the hippocampus in one case. We reviewed longitudinal clinical and MRI data covering 53 and 36 months after LE without immunotherapy, respectively. Both patients became seizure-free and spontaneously recovered with mild/moderate cognitive impairment. No relapses have been observed. Follow-up brain MRI indicated early hippocampal sclerosis and global brain atrophy in one case characterized by more pronounced cognitive deficit. Memory and verbal fluency were affected most during the natural course of LGI1 encephalitis. LGI1 encephalitis had a monophasic course and spontaneously improved, suggesting that a relatively benign natural course may contribute to the favorable outcome observed after immunotherapy. Our data also indicate that LGI1 antibodies can be present in the sera without clinical disease activity.
authors.affiliation: Department of Neurology, Mor Kaposi General Hospital, Kaposvar, Hungary.
authors.forename: Monika
authors.initials: M
authors.lastname: Szots
authors.affiliation: Department of Neurology, Mor Kaposi General Hospital, Kaposvar, Hungary.
authors.forename: Annamaria
authors.initials: A
authors.lastname: Marton
authors.affiliation: Diagnostic Center of Pecs, Pecs, Hungary.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Kover
authors.affiliation: Markusovszky Teaching Hospital, Szombathely, Hungary.
authors.forename: Tunde
authors.initials: T
authors.lastname: Kiss
authors.affiliation: Department of Immunology and Biotechnology, University of Pecs, Pecs, Hungary.
authors.forename: Timea
authors.initials: T
authors.lastname: Berki
authors.affiliation: Department of Neurology, Mor Kaposi General Hospital, Kaposvar, Hungary.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Nagy
authors.affiliation: Department of Neurology and Institute of Clinical Research, Odense University Hospital, University of Southern Denmark, Odense, Denmark. Electronic address: zsolt.illes@rsyd.dk.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Illes
mesh_terms: D000906:Antibodies / Q000097:blood*; D001921:Brain / Q000473:pathology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D020363:Limbic Encephalitis / Q000097:blood / Q000473:pathology / Q000628:therapy; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011506:Proteins / Q000276:immunology*; D013997:Time Factors
chemical_list: D000906:Antibodies; D047908:Intracellular Signaling Peptides and Proteins; C116499:LGI1 protein, human; D011506:Proteins
keywords: Antibody-mediated encephalitis; Faciobrachial dystonic seizures; Hyponatremia; LGI1; Limbic encephalitis; Surface neuronal antibodies