Coexistence of anti-GluK2 and anti-LGI1 antibodies in a patient with autoimmune encephalitis: a rare case report and literature review

Autoimmune encephalitis (AE) is a neurologic dysfunctional disorder resulting from diffuse or multiple inflammatory lesions in the brain parenchyma mediated by autoimmune mechanisms. The diagnosis of AE relies on the detection of specific autoantibodies in serum or cerebrospinal fluid, which help define distinct clinical syndromes and guide immunotherapy. However, its clinical manifestations can be diverse and atypical, posing a great challenge for early diagnosis. We report the first case in Asia of an adult female with autoimmune encephalitis who tested positive for both serum anti-GluK2 and anti-LGI1 antibodies. Cranial magnetic resonance imaging (MRI) revealed abnormal signals in the right hippocampus. Her clinical presentation was atypical, characterized by paroxysmal nervousness and panic attacks. She showed a favorable response to immunotherapy with methylprednisolone and mycophenolate mofetil. This case highlights the diagnostic challenges posed by atypical presentations of AE and the importance of antibody testing in such settings. We also review the relevant literature to improve the diagnosis and management of atypical AE.