A Metabolic Brain Pattern Associated With Anti-N-Methyl-D-Aspartate Receptor Encephalitis

Psychosomatics. 2020 Jan-Feb;61(1):39-48. doi: 10.1016/j.psym.2019.08.007. Epub 2019 Sep 5.


Background: Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis causes substantial neurological disability. Autoantibodies causing encephalitis directed against the neuronal cell surface or synapse are of diagnostic importance giving the possibility of successful immunotherapy.

Objective: In this study, we aim to provide supporting evidence that brain 18F-FDG-PET may be helpful in identifying likely patterns of regional brain glucose metabolism.

Methods: Thirty-three patients (18 men and 15 women; age range of 17-55 y) with positive NMDA receptor antibody encephalitis that underwent an 18F-FDG-PET imaging examination were prospectively selected and compared with a reference group of 14 brain 18F-FDG-PET scans from healthy volunteers using voxel-based statistical analysis. Clusters of hyper- and hypo-metabolism were reported for the whole sample of patients (FWE-corrected P < 0.05), and uncorrected at P < 0.005 for a group of relapsed patients.

Results: Mixed metabolic patterns (focal/bilateral hypermetabolism in the temporal lobe, insula, and cerebellum; associated with severe bilateral hypometabolism in the occipital and parietal lobes) were found.

Conclusions: Our findings suggest that 18F-FDG-PET should be included as an imaging tool when assessing affected patients in the clinical workup to rule out anti-NMDA encephalitis and help determine the most effective treatment.

Keywords: FDG; acute disorder; encephalitis; neuropsychiatry; positron emission tomography.

MeSH terms

  • Adolescent
  • Adult
  • Anti-N-Methyl-D-Aspartate Receptor Encephalitis / diagnostic imaging*
  • Anti-N-Methyl-D-Aspartate Receptor Encephalitis / metabolism
  • Anti-N-Methyl-D-Aspartate Receptor Encephalitis / physiopathology
  • Aphasia / physiopathology
  • Brain / diagnostic imaging*
  • Brain / metabolism
  • Brain / physiopathology
  • Catatonia / physiopathology
  • Cerebellum / diagnostic imaging
  • Cerebellum / metabolism
  • Cerebral Cortex / diagnostic imaging
  • Cerebral Cortex / metabolism
  • Delirium / physiopathology
  • Electroencephalography
  • Female
  • Fluorodeoxyglucose F18
  • Hallucinations / physiopathology
  • Humans
  • Lethargy / physiopathology
  • Magnetic Resonance Imaging
  • Male
  • Memory Disorders / physiopathology
  • Memory, Short-Term
  • Middle Aged
  • Movement Disorders / physiopathology
  • Occipital Lobe / diagnostic imaging
  • Occipital Lobe / metabolism
  • Parietal Lobe / diagnostic imaging
  • Parietal Lobe / metabolism
  • Positron-Emission Tomography
  • Radiopharmaceuticals
  • Temporal Lobe / diagnostic imaging
  • Temporal Lobe / metabolism
  • Young Adult


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18