CHRONIC STEROID-RESPONSIVE ENCEPHALITIS WITHOUT AUTOANTIBODIES TO GLUTAMATE-RECEPTOR GLUR3

Autoantibodies to GluR3, an AMPA glutamate receptor subtype, may be a cause of chronic unilateral encephalitis (Rasmussen's syndrome). We re port a woman with chronic left hemisphere encephalitis whose partial s eizures, aphasia, and motor weakness are highly responsive to intermit tent steroids and cyclophosphamide. Her serum and CSF were negative fo r antibodies to GluR3 by both immunoblot and immunocytochemical analys is of cells transfected with GluR3 cDNA, indicating that separate immu ne-mediated processes may be involved in some cases of chronic encepha litis.