Anti-LGI1 Encephalitis

Anti-LGI1 encephalitis is an autoimmune limbic encephalitis caused by antibodies against the leucine-rich glioma-inactivated 1 protein. It typically affects middle-aged adults and presents with faciobrachial dystonic seizures, memory impairment, hyponatremia, and behavioral changes. MRI may show hyperintensities in the medial temporal lobes. Diagnosis relies on detection of anti-LGI1 antibodies in serum or CSF. Management includes immunotherapy (corticosteroids, IVIG, rituximab), with early treatment improving cognitive outcomes and reducing seizure burden.