Abstract
Background
Magnetic resonance imaging findings of anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis have been reported to lack specificity. The hippocampus, frontal lobe, white matter, basal ganglia, and even spinal cord can be involved. However, isolated leptomeningeal enhancement is rare in anti-NMDA receptor encephalitis.
Case presentation
We report a 17-year-old boy who presented with a 2-week history of mild fever and progressive encephalopathy with behavioral and psychological abnormalities. Finally, a diagnosis of anti-NMDA receptor encephalitis was made. Initial magnetic resonance imaging results revealed diffuse contrast enhancement of the leptomeninges without parenchymal lesions. After treatment with high-dose intravenous methylprednisolone, plasma exchange, and intravenous immunoglobulin, the enhancement showed substantially decrease at the 3-week follow-up.
Conclusions
This case is unusual because isolated leptomeningeal enhancement is rare in anti-NMDA receptor encephalitis. The present case suggests that isolated diffuse leptomeningeal enhancement could be one of the imaging findings in patients with anti-NMDA receptor encephalitis.
Magnetic resonance imaging and positron emission tomography in anti-NMDA receptor encephalitis: A systematic review
