Anti-NMDAR encephalitis in a pediatric hospital from 2010 to 2022

*Correspondence: [e-mail].

Abstract

Background: Autoimmune encephalitis is the leading cause of non-infectious etiology encephalitis in the world. In 2005, the main antibody against the surface of neurons receptor anti N-Methyl-D-Aspartate (anti-NMDAr) was described, triggered by viral infections or tumors. The clinical presentation has an acute or subacute onset with symptoms such as language and/or behavioral changes, psychiatric disturbances, movement disorders, epileptic seizures, dysautonomia, and decreased level of consciousness. There are few Brazilian studies on autoimmune encephalitis in the pediatric population in Brazil.

Objective: To obtain epidemiological and clinical information on anti-NMDAr encephalitis in childhood, filling a gap in knowledge about the subject. To identify the frequency of autoimmune encephalitis from January 2010 to November 2022, according to age and gender, as well as the clinical presentation and outcome of patients with positive autoantibodies.

Methods: This is a retrospective, observational, and descriptive study carried out through medical records of pediatric patients hospitalized between 2010 and 2022 in a tertiary children's hospital in Curitiba, Paraná, Brazil, diagnosed with autoimmune encephalitis with positive autoantibodies.

Results: Thirteen patients between 8 months and 17 years of age were identified, with a predominance of females. Most patients required hospitalization in a pediatric ICU at some point. At least two of the classic triad symptoms, alteration of the level of consciousness, seizures, and movement disorders, were present in all patients. There was a correlation with viral infection, and no cases associated with germ cell tumors were registered in the analyzed sample. Treatment was initiated late. There were no deaths among the patients in the sample.

Conclusion: The incidence is likely underestimated, as confirmed by data from the literature, due to difficulties in accessing diagnostic tests. Cardinal symptoms such as alteration of the level of consciousness, movement disorders, and seizures were present in most patients. Regarding treatment, all patients required more than one option among first-line therapies, and 76% required second-line therapies due to failure to remit symptoms.

Publication History

Article published online:
12 May 2025