Anti-NMDA receptor encephalitis

Background

Anti-NMDA receptor encephalitis is an under-recognized neurologic disorder due to antibodies to the NMDA receptor and is often associated with a tumor (most commonly ovarian teratoma)

Clinical Features

History

Female predominance (up to 80-90%)
Predominantly in children and young adults, however can be found at any age
Viral like prodrome (HA, low-grade fever, malaise)
Psychiatric manifestations (anxiety, agitation, bizarre behavior, hallucinations, etc)and or decreased level of consciousness
Dyskinesia, movement disorders and increased rigidity
Autonomic instability: hyperthermia, tachy/brady,BP fluctuations, hypoventilation
Lethargy, seizures

Physical

Abnormality in vitals as above, rarely may find abdominal mass

Differential Diagnosis

viral encephalitis
neuroleptic malignant syndrome
primary psychiatric disorder
hyper/hypothyroidism
Cushings Syndrome
Addisons disease
lethal catatonia
cerebral space occupying lesions
Drugs, toxins, withdrawl

Workup

Dx confirmed by detection of antibodies to NR1 subunit of NMDAR in CSF or serum (typically send-out lab)
LP: CSF lymphocytic pleocytosis or oligoclonal bands (can be normal initially)
EEG: to rule out seizure with movement disorders
MRI brain: normal or transient FLAIR or contrast enhancing abnormalities in cortical or subcortical regions
Pelvic US or CT or MRI to evaluate for associated ovarian tetratoma

Management

Resection of tumor
Glucocorticoids
IVIG
plasma exchange
Second line rituximab and cyclophosphamide

Disposition

Admission

External Links

http://lifeinthefastlane.com/education/ccc/anti-nmda-receptor-encephalitis/
http://www.thepoisonreview.com/2013/08/28/must-read-anti-nmda-receptor-encephalitis/
http://www.antinmdafoundation.org/what-is-anti-nmda-receptor-encephalitis.html
http://www.cicm.org.au/journal/2013/march/ccr_15_1_010313-008.pdf

Sources

thepoisonreview.com lifeinthefastlane.com

Authors: