Teaching NeuroImages: 18F-FDG-PET/SPM analysis in 3 different stages from a patient with LGI-1 autoimmune encephalitis.

A 50-year-old woman presented with faciobrachial dystonic seizures for about 50 days during sleeping (figure, A). Initial MRI scan was normal, but FDG-PET showed hypermetabolism in the basal ganglia (BG) and medial temporal lobes (MTLs) (figure, B). Clinical symptoms raised a strong suspicion of LGI-1 autoimmune encephalitis (AE) diagnosis, and LGI-1 antibody titer examination (serum and CSF) confirmed the suspicion.1,2 After relapse, the patient showed a previous PET abnormal pattern.