Clinical Features of Children With Anti-N-Methyl-D-Aspartate Receptor Encephalitis Following Viral Encephalitis.

BACKGROUND

Anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDARE) can occur after herpes simplex encephalitis (HSE) and Japanese encephalitis (JE). We describe the clinical features of children with anti-NMDARE after viral encephalitis.

OBJECTIVE

This study aims to describe the clinical characteristics, laboratory findings, and treatment outcomes of these patients.

METHODS

We describe the clinical characteristics of 14 children of anti-NMDARE following viral encephalitis treated at National Children's Hospital from January 2021 to December 2022. Patients with evidence of viral reactivation or other antibodies were excluded.

RESULTS

There are 12 children with anti-NMDARE after HSE and 2 children after JE. The median age was 2.1 years (range 0.6-12.9), with 8 male patients. All patients (100%) had fever and seizures, while 50% exhibited focal neurological signs. No patients experienced movement disorders, psychiatric symptoms, or sleep disturbances during the viral encephalitis phase. In contrast, the most common symptoms during the anti-NMDARE phase were as follows: movement disorders in 92.9% (13/14), recurrent or prolonged fever in 71.4% (10/14), sleep disturbances in 64.3% (9/14), seizures in 50% (7/14), and psychiatric symptoms in 50% (7/14). The median cerebrospinal fluid (CSF) white blood cell count in the viral encephalitis and anti-NMDARE phases was 57 (4-410) and 13 (2-48), respectively. The mean CSF protein concentration was 0.43 ± 0.16 g/L and 0.85 ± 0.63 g/L, respectively. Brain MRI was performed in both encephalitis phases for 10/14 patients, with 8/10 showing no new lesions.

CONCLUSION

There were differences in clinical symptoms and CSF findings between the two phases of encephalitis; however, most patients did not develop new lesions on brain MRI.