Elsevier

Seizure

Volume 20, Issue 3, April 2011, Pages 266-270
Seizure

Case report
Anti-NMDA receptor encephalitis presenting with imaging findings and clinical features mimicking Rasmussen syndrome

https://doi.org/10.1016/j.seizure.2010.11.013Get rights and content
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Abstract

Background

Antibody mediated anti-N-methyl-d-aspartate (NMDA) receptor encephalitis is a recently reported diagnosis of clinical importance. Recognition of the syndrome, especially in pediatric populations, is difficult and often undiagnosed and/or confused with neurological disorders with similar clinical features.

Results

We report a case of an 11 year old female with explosive-onset epilepsy and predominantly unilateral frontal lobe abnormalities on magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) neuroimaging. A diagnosis of Rasmussen syndrome (RS) was considered. Cerebrospinal fluid analysis revealed strong positivity for NMDA receptor antibodies. Screening for occult ovarian teratoma with computed tomography (CT) and MRI initially did not demonstrate associated tumor. Treatment with steroids and plasma exchange improved her clinical course and subsequent MRI showed resolution.

Conclusion

NMDA receptor encephalitis has variable neuroimaging manifestations, and can mimic other entities. We emphasize the clinical syndrome of NMDA receptor encephalitis and consideration of the diagnosis in evaluating a child with explosive-onset epilepsy, unilateral imaging abnormalities, and neurocognitive decline.

Keywords

NMDA receptor
Encephalitis
Children
Rasmussen syndrome
Neuroimaging
Treatment

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