Overview
Autoimmune encephalitis (AIE) encompasses a spectrum of disorders characterized by immune-mediated neuronal dysfunction, often involving antibodies against neuronal surface or synaptic proteins, leading to diverse neurological and psychiatric symptoms 134.Diagnosis
Clinical Presentation: Varied, including seizures, cognitive impairment, psychiatric symptoms, and movement disorders 146.
Imaging: MRI may show characteristic lesions but has lower sensitivity compared to FDG PET, which often reveals metabolic abnormalities in affected brain regions 1.
Serological Testing: Detection of specific antibodies (e.g., anti-NMDAR, anti-MOG) is crucial but seronegative cases also exist 34.
FDG PET: Highly sensitive for detecting metabolic changes; abnormal findings reported in 93% of cases 1.
Radiologic Findings: Specific patterns like optic nerve involvement, spinal cord lesions, and brainstem abnormalities can guide diagnosis in MOG antibody-associated disease 2.Management
First-Line Treatments:
- Immunotherapy: Intravenous immunoglobulin (IVIG) and corticosteroids (e.g., intravenous methylprednisolone, oral prednisone) 37.
Adjunctive Treatments:
- Second-Line Immunotherapy: Plasma exchange, rituximab, or cyclophosphamide for refractory cases 6.
- Symptomatic Management: Anticonvulsants for seizures, antipsychotics for psychiatric symptoms, and specific neuromodulators for movement disorders 6.Special Populations
Pediatrics: Common presentations include ADEM in younger children and optic neuritis/myelitis in older children and adults 2.
Comorbidities: AIE can coexist with other autoimmune conditions (e.g., primary biliary cirrhosis) and may present with unique complications like rhabdomyolysis 57.Key Recommendations
Utilize FDG PET for enhanced diagnostic sensitivity in suspected AIE cases (Evidence: Strong 1).
Include serological testing for specific antibodies (e.g., anti-NMDAR, anti-MOG) in the diagnostic workup, recognizing the possibility of seronegative presentations (Evidence: Moderate 34).
Initiate first-line immunotherapy with IVIG and corticosteroids for confirmed AIE; escalate to second-line therapies like rituximab for refractory cases (Evidence: Moderate 67).
Tailor management to specific clinical presentations and patient age groups, considering unique pediatric presentations and comorbid autoimmune conditions (Evidence: Expert opinion 257).References
1 Kosek S, Kilsved E, Danfors T, Cunningham JL, Pavel R, Rostedt Punga A et al.. Regional Metabolic Abnormalities in Autoimmune Encephalitis: A Meta-analysis of 498 Cases With Brain FDG PET. Clinical nuclear medicine 2025. link
2 Giorgi L, Marignier R, Pique J, Maurey H, Papeix C, Ciron J et al.. French guidelines for the diagnosis and management of MOG antibody-associated disease. Revue neurologique 2025. link
3 van Steenhoven RW, Titulaer MJ. Seronegative autoimmune encephalitis: exploring the unknown. Brain : a journal of neurology 2022. link
4 Chen L, Zhu L, Lu D, Dai S, Han Y, Wu Z et al.. Association between autoimmune encephalitis and epilepsy: Systematic review and meta-analysis. Seizure 2021. link
5 Chen SM, Zhang YF, Liu GH, Li L, Zhang HJ, Zhou L. Recurrent panic attack and bilateral hippocampus lesions as main manifestation in an autoimmune encephalitis associated with primary biliary cirrhosis. Chinese medical journal 2020. link
6 Ali F, Wijdicks EF. Treatment of Movement Disorder Emergencies in Autoimmune Encephalitis in the Neurosciences ICU. Neurocritical care 2020. link
7 Li R, Jiang L, Li XJ, Hong SQ, Zhong M, Hu Y. Analysis and discussion of the rare complication of autoimmune encephalitis: Two case reports. Medicine 2018. link