PSYCHIATRIC SYMPTOMS IN ANTI GLUTAMIC ACID DECARBOXYLASE ASSOCIATED LIMBIC ENCEPHALITIS IN ADULTS: A SYSTEMATIC REVIEW.

Abstract Autoimmune Limbic Encephalitis (LE) is a relatively new category of immune-mediated diseases with a wide range of neuropsychiatric symptoms. LE associated with Glutamic Acid Decarboxylase (GAD) antibodies is difficult to diagnose due to its possible atypical presentation with neuropsychiatric and behavioral features. We performed a systemic review of literature and retrieved 21 cases of anti GAD-associated LE with neuropsychiatric signs. Median age at onset was 27 years with a female predominance (81.0%) and median diagnostic delay 6 months. Clinical presentation included typical LE symptoms such as anterograde amnesia (95.2%) and temporal lobe or tonico-clonic seizures (95.2%). Psychiatric symptoms were described in 61.9% of patients, presenting as anxiety, depressive symptoms, apathy and behavioral changes. Extra-limbic symptoms were present in 14.3% of patients. No neoplasia associated was found. Some patients had poor epileptic, cognitive and psychiatric outcomes requiring prolonged immunosuppressive treatment. The description of the neuropsychiatric spectrum of anti-GAD LE and its specificities aims to improve our understanding of this entity, and may lead to earlier diagnosis as well as better outcome.