Development and validation of the Pediatric Autoimmune encephalitis Severity Scale in children with autoimmune encephalitis

Abstract

Autoimmune encephalitis is a rare condition in children in which the body's immune system mistakenly attacks the brain, leading to problems such as seizures, changes in behavior, agitation, memory loss, excessive movements, and, in some cases, a total loss of awareness. Doctors need reliable tools to assess the severity of the illness. This helps them determine how severe the illness is, how to treat it, and how to monitor the response to treatment. It also helps compare treatments given at various centers worldwide. The existing assessment tools were primarily designed for adults and may not fully capture the problems seen in children. In this study, we developed the Pediatric Autoimmune Encephalitis Severity Scale (PASS), a scale specifically designed to assess the severity of autoimmune encephalitis in children. The scale was created using expert opinions and a structured process to reach agreement among specialists. It was then tested at two hospitals over a 21-month period by serially evaluating children with autoimmune encephalitis to assess its accuracy and consistency. PASS showed excellent agreement among doctors using the scale, indicating that clinicians could score children similarly. The scale captured serial changes in disease severity and performed as well as or slightly better than the existing scales. The PASS score also correlated with children's later quality of life.