REVERSIBLE PARANEOPLASTIC LIMBIC ENCEPHALITIS ASSOCIATED WITH ANTIBODIES TO THE AMPA RECEPTOR

Abstract

Until recent years, autoimmune limbic encephalitis (LE) was mostly viewed as a paraneoplastic disorder associated with onconeuronal antibodies to intracellular antigens (mainly Hu, Ma2). Except for some patients with Ma2 antibodies, the outcome was considered poor.1,2 Currently, a growing number of immune responses against cell surface neuronal receptors are being described in patients previously considered antibody-negative.3–5 One of these new antigens is the GluR1/2 alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (or AMPA receptor [AMPAR]).6 Recognizing the syndrome associated with AMPAR antibodies is important because symptoms are often fully reversible. Here we report the clinical features of one of the patients whose serum and CSF were used to isolate this antigen. ### Case reports. A 67-year-old woman came to our attention because of behavior and memory problems. She had been well until March 2008, when a right breast ductal infiltrating adenocarcinoma (T1, N1, M0) was diagnosed after routine screening mammography. In the ensuing hours after breast surgery she developed confusion, hypersomnia, visual hallucinations, and combativeness. On the following days she improved slightly, and was discharged. Due to persistent symptoms she was admitted to the neurology ward 2 weeks later. On examination she was calm, alert, and cooperative, with a mild depressed affect. She had decreased verbal fluency, but language function was otherwise normal. She knew her name and recognized family members without difficulty. She knew that she was in the hospital and was …