Marked improvement of anti-N-methyl-D-aspartate receptor encephalitis by large-dose methylprednisolone and plasmapheresis therapy combined with 18F-fluorodeoxyglucose positron emission tomography imaging: A case report

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, a recently defined and frequently misdiagnosed disease characterized by psychiatric symptoms, seizures, movement disorders and autonomic dysfunction, has been observed predominantly in young females with ovarian teratoma. Conventional imaging techniques, including computed tomography (CT) and magnetic resonance imaging (MRI), are often ineffective for diagnosis of the disease. If diagnosed early, the initiation of immunotherapy and removal of the tumor (if present) may result in recovery. The current study presents the case of a 38-year-old female with classic clinical symptoms of anti-NMDAR encephalitis. The MRI brain scan results were unremarkable, cerebral spinal fluid (CSF) biochemistry indicated non-specific lymphocytic pleocytosis and the CSF microbiology studies were negative. 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging revealed significant generalized asymmetric hypometabolism. The patient demonstrated marked recovery following treatment with a high dose of corticosteroids and plasmapheresis. Accordingly, the follow-up 18F-FDG PET imaging revealed significant improvement.