title: Limbic encephalitis associated with anti-voltage-gated potassium channel complex antibodies as a cause of adult-onset mesial temporal lobe epilepsy.
abstract: Recently, some reports have indicated that limbic encephalitis associated with anti-voltage-gated potassium channel complex antibodies (VGKC-Ab) is a cause of adult-onset mesial temporal lobe epilepsy (MTLE). We report a 53-year-old woman who had her first epileptic seizure at the age of 50 years old. Examination by 3-Tesla brain MRI revealed left hippocampal high signal intensity and swelling on fluid-attenuated inversion recovery (FLAIR) and T2-weighted imaging at 2 months after her first seizure. The patient received intravenous methylprednisolone and carbamazepine 300 mg/day. One month later, MRI revealed improvement of her left hippocampal abnormalities. Thereafter, she had no seizures, however, three years after her first seizure, EEG revealed a seizure pattern in the left temporal region. Brain MRI revealed left hippocampal high signal intensity and brain fluorodeoxyglucose positron emission tomography revealed hypermetabolism. Her serum VGKC-Ab levels were 118 pM(normal < 100 pM). Intravenous methylprednisolone therapy was reinitiated. Two months later, her hippocampal abnormalities had improved and 3 months later her VGKC-Ab levels decreased to 4.4 pM. Remission of the epileptic seizures was also observed. This MTLE in the middle age was considered as limbic encephalitis associated with anti- VGKC-Ab. In cases of unexplained adult-onset MTLE, limbic encephalitis associated with anti-VGKC-Ab, which responds well to immunotherapy, should be considered in the differential diagnosis.
authors.affiliation: Department of Neurology, School of Medicine, University of Occupational and Environmental Health, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Toyota
authors.forename: Naoki
authors.initials: N
authors.lastname: Akamatsu
authors.forename: Sadatoshi
authors.initials: S
authors.lastname: Tsuji
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nishizawa
mesh_terms: D001323:Autoantibodies / Q000276:immunology*; D004833:Epilepsy, Temporal Lobe / Q000209:etiology*; D005260:Female; D006801:Humans; D020363:Limbic Encephalitis / Q000150:complications / Q000276:immunology*; D008875:Middle Aged; D024642:Potassium Channels, Voltage-Gated / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D024642:Potassium Channels, Voltage-Gated