Examining causes of pediatric encephalitis

Encephalitis can lead to neurologic morbidity and mortality in children. A new study in Pediatrics examines the infectious and autoimmune causes of encephalitis in pediatric patients.¹

The researchers retrospectively reviewed medical records from pediatric patients in Houston, Texas, who were diagnosed with encephalitis in both an urban and rural catchment area between 2010 and 2017. They found 231 patients who met the case definition of encephalitis.

Among the cohort of 231 patients, 42% had no recognized etiology. Among cases with an identified etiology, the most common was infectious, which accounted for 73 cases. Among the 51 with a viral cause, the most common was West Nile virus, which accounted for 12 cases. In the 19 bacterial cases, the most frequent etiology was Bartonella henselae, with 7 cases. In the 60 cases of autoimmune encephalitis, the most frequent cause was anti–N-methyl-D-aspartate receptor (NMDAR) encephalitis (31). Investigators found that autoimmune causes for encephalitis were more commonly found in female patients. Testing for enterovirus and herpes simplex virus were nearly universal, but testing for B henselae, West Nile virus, and anti-NMDAR encephalitis were not.

Investigators found that increasing testing for anti-NMDAR encephalitis led to more frequent identification of cases. They believe that increased awareness and testing for West Nile virus and B henselae would lead to a similar increase in identifying pediatric encephalitis, which is important as earlier etiologic diagnosis leads to improved clinical outcomes.

References:

1. Erickson TA, Muscal E, Munoz FM, et al. Infectious and autoimmune causes of encephalitis in children. Pediatrics. 2020;145(5):e20192543. doi: 10.1542/peds.2019-2543