A 65-year-old woman with a history of mild cognitive deficit (short-term memory and attention) developed recurrent confusional states, confabulation, aggressive behaviors, and delusions. Frequent episodes of dystonic contraction of the left upper limb and hemifacial spasm were reported by the caregiver. These episodes were interpreted as faciobrachial dystonic seizures (FBDS). A brain and body [18F]FDG PET/MR was requested that was consistent with an autoimmune encephalitis. Anti-neural antibody screening disclosed anti-LGI1 abs on both serum and CSF. The patient was diagnosed with limbic encephalitis according to Graus criteria.