Follow-up younger patient with anti-NMDA-R encephalitis

Case presentation: Male, 8 months old, previously healthy, initiated with fever, inappetence, dystonia and axial hypotonia. Initial examination presented cerebrospinal fluid (CSF) with lymphomononuclear leukocytosis and proteinorrachia. Electroencephalogram (EEG) with slowed base activity. Other infectious screening tests with viral serology, rheumatological, neoplastic diseases, nuclear magnetic resonance (NMR) imaging of the brain were standard. After exclusion of main causes of encephalitis, antibodies against N-methyl-D-aspartate receptor (NMDA-R) were identified in the CSF. It evolved with worsening motor and respiratory, and regression of neuropsychomotor development (NPMD), he needed tracheostomy (TQT) and gastrostomy (G-tube). Treatment, besides a front line with steroids and Human Immunoglobulin, were six cyclophosphamide cycles and starting azathioprine, remaining hospitalized for four months. Following up, at five years of age, he is still using azathioprine, in weaning. He presents NPMD milestones appropriate for his chronological age. There is no need for tracheostomy (TQT) and gastrostomy (G-tube).

Discussion: This case report exposes a younger patient with anti-NMDA-R encephalitis among those reported in the literature. It is an immune-mediated syndrome with antibodies in serum and/or CSF against an epitope located in extracellular domain of NMDA-R. It is the second most common cause of autoimmune encephalitis. Clinical signs include seizures, behavior, speech, and movement disorders. The diagnosis is based on CSF analysis–showing lymphocytic pleocytosis, EEG, and the detection of autoantibodies. The differential diagnosis includes psychiatric disorders and other viral encephalitis. Several reports of anti-NMDA-R encephalitis in patients with current or recent Severe Acute Respiratory Syndrome of SARS-CoV-2. First-line immunotherapy treatments are steroids. In refractory cases, cyclophosphamide, rituximab, or azathioprine might be added, with a slow recovery time. The mortality rate is 4% associated with secondary comorbidities acquired in the intensive care unit (ICU).

Final comments: Anti-NMDA-R encephalitis should be suspected in children with acute behavioral change, seizures, movement disorders, associated with CSF pleocytosis lymphocytic and/or EEG with slow and disorganized activity and/or normal brain NMR. The autoimmune picture identification and aggressive management at its first stages lead to a more favorable outcome in the follow-up, as presented in this report.

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Publikationsverlauf

Artikel online veröffentlicht:
18. September 2023