Abstract: Objective：To report a case of leucine-rich glioma inactivated-1 protein antibody (LGI1-Ab) associated limbic encephalitis. Methods: A 76-year-old woman was admitted to the hospital because of cognitive impairment and faciobrachial dystonic seizures for six months. Hyponatremia was also noted in this patient. Antibodies to the LGI1 were positive.18F-FDG uptake was measured on the PET-CT scans of this patient. Results: PET-CT showed bilateral putamen hypermetabolism with hypometabolism in other regions. Her symptoms were improved after intravenous immunoglobulin therapy. Conclusion: LGI1-Ab associated encephalitis can manifest as basal ganglia hypermetabolism and faciobrachial dystonic seizures.

Key words: LGI1 protein, human, Limbic encephalitis, Positron-emission tomography