Anti-Glutamic Acid Decarboxylase (GAD) encephalitis: Anti-GAD antibodies are not typically associated with malignancy but associated with other non-neoplastic autoimmune conditions such as type 1 diabetes mellitus. Classic temporal lobe lesions on magnetic resonance (MR) imaging with the expected clinical findings of limbic encephalitis plus additional features of stiff person syndrome. This evidence concerns the gene GAD1 and encephalitis.