18F-FDG PET/CT in Initial Diagnosis and Treatment Response Evaluation of Anti-NMDAr and Anti-GAD Dual Antibody Autoimmune Encephalitis

Clin Nucl Med. 2021 Jan;46(1):e63-e64. doi: 10.1097/RLU.0000000000003379.


We report a case of 34-year-old woman presenting with complaints of abnormal posturing of hand and tonic-clonic seizures of few days' duration, which soon progressed to psychotic episodes and injuries secondary to fall/abnormal movements. She underwent F-FDG PET for a suspicion of encephalitis, which revealed increased FDG uptake in the bilateral parietotemporal lobes (right more than left), anterior cingulate cortex, bilateral basal ganglia, thalami, and cerebellum. This atypical pattern did not conform to any known pattern of encephalitis, which was later attributed to the presence of both anti-NMDAr and anti-GAD antibodies in blood and cerebrospinal fluid.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Anti-N-Methyl-D-Aspartate Receptor Encephalitis / diagnostic imaging*
  • Anti-N-Methyl-D-Aspartate Receptor Encephalitis / therapy*
  • Encephalitis / diagnostic imaging*
  • Encephalitis / therapy*
  • Female
  • Fluorodeoxyglucose F18*
  • Hashimoto Disease / diagnostic imaging*
  • Hashimoto Disease / therapy*
  • Humans
  • Positron Emission Tomography Computed Tomography*
  • Treatment Outcome


  • Fluorodeoxyglucose F18

Supplementary concepts

  • Hashimoto's encephalitis