1111 - An Unprecedented Influx of Pediatric Autoimmune Encephalitis in an Inpatient Rehabilitation Hospital: A Case Series

Autoimmune encephalitis (AE) encompasses a range of inflammatory neurologic disorders that are non-infectious and immune-mediated. The most common type of AE is Anti-N-methyl-D-aspartate (Anti-NMDA) receptor encephalitis, which involves autoantibodies targeting the N1 subunit of NMDA receptors in the brain. This condition impairs neuronal plasticity and leads to an acute-to-subacute deterioration in cognitive and neuropsychiatric function. Patients may present with a constellation of symptoms including but not limited to new-onset seizures, movement disorders, sleep disturbances, language dysfunction and encephalopathy. Additionally, the condition can be associated with malignant tumors, most commonly ovarian teratomas.

Case Description: Here we present a case series of five patients with AE between 3 and 16 years of age who presented to the pediatric unit of our rehabilitation hospital between June and August 2024. Four of the five patients had anti-NMDA receptor encephalitis, one of whom was found to have an associated ovarian teratoma. All patients were treated with steroids and intravenous immunoglobulins or plasma exchange in the acute care setting. During their admission, they received multidisciplinary care from physiatry, psychology, and allied therapists, focusing on improving physical, cognitive, and psychiatric symptoms of encephalitis. Length of stay ranged from 10 to 29 days.

Discussions:

Considering the low incidence of AE in the general population, the admission of five patients with AE within a span of two months is unusual. Although the cause for this high number of cases is unknown, it provided us with unique insight on the efficacy of rehabilitation in a pediatric population with AE. All five patients showed significant improvement in multiple functional areas after a focused inpatient rehabilitation course.

Conclusions:

Pediatric patients with autoimmune encephalitis can demonstrate significant improvement in their overall function from an intensive inpatient rehabilitation program designed to focus on impairments caused by this rare condition.