Autoimmune encephalitis -- new awareness, challenging questions.

Area of Science:

• Neuroimmunology
• Neurology
• Immunology

Background:

• Autoimmune encephalitides are increasingly recognized neurological disorders.
• Many cases involve autoantibodies against neuronal cell-surface proteins crucial for neuronal excitability.

Purpose of the Study:

• To review the expanding field of autoimmune encephalopathies.
• To discuss the pathogenic mechanisms and potential etiologies of these conditions.

Main Methods:

• Review of clinical and scientific data on autoimmune encephalitis.
• Analysis of patient cohorts defined by serum autoantibodies.

Main Results:

• Identified key autoantibodies (LGI1, CASPR2, NMDA, AMPA, GABA(B) receptors) and associated phenotypes.
• Highlighted immunotherapy responsiveness and tumor associations.
• Noted expanded phenotypes including epilepsy and psychosis, and potential progression to hippocampal sclerosis.

Conclusions:

• Autoantibodies are strongly implicated in the pathogenicity of these encephalitides.
• Tumors can trigger autoantibody production, but etiology remains unclear in many cases.
• Models incorporating serum antibody generation, blood-brain barrier, and intrathecal production are proposed.