Abstract

Nearly half of all cases of acute encephalitis did not have an identifiable cause. Autoimmune (antibody-mediated) etiology has gained more recognition over the recent years. It is important to consider the diagnosis by the clinical findings of acute limbic encephalopathy, new onset schizophrenia, or new onset medically refractory seizures. Identification of the antibodies is important in defining the underlying causes including underlying malignancies. Antibodies against intracellular proteins are more likely to be paraneoplastic and T-cell mediated. Antibodies against cell surface or synaptic antigens are mostly B-cell mediated and they are more responsive to immunotherapy. In addition to high index of clinical suspicion, MRI, serum and CSF antibody testing are most helpful in making the final diagnosis.