A 70-year-old man was brought to the emergency room in an unconscious state. A cerebrospinal fluid analysis demonstrated strongly positive autoantibody glutamate receptor epsilon 2 (GluRε2) titer, corresponding to anti-N-methyl-D-aspartate receptor (anti-NMDAR) NR2B autoantibody titers. The patient was diagnosed with limbic encephalitis. Brain MRI showed a high intensity in the left anterior-temporal lobe on T2WI/fluid attenuated inversion recovery (FLAIR) images, without enhancement. In this area, F-FDG PET showed a relatively decreased uptake, but C-methionine PET showed mildly increased uptake. Despite the patient's near-full functional recovery, similar PET findings were confirmed 6 months later. The mechanism of regional cerebral increased C-methionine uptake in anti-NMDAR (NR2B) receptor encephalitis is unknown.
Clinical nuclear medicine 04/2012; 37(4):400-2. DOI:10.1097/RLU.0b013e3182443c92 · 2.86 Impact Factor