Abstract: To explore the clinical features and prognosis of children with anti-N-methyl-D-aspartatereceptor (NMDAR) encephalitis complicated with rhabdomyolysis (RM). Methods The clinical data of 4 children with anti-NMDAR encephalitis complicated with RM were retrospectively analyzed. Results There were 3 boys and 1 girl with an average onset age of ( 9 . 3 ±4 . 3 ) years. The median time between onset symptom and diagnosis of anti-NMDAR encephalitis was 14 ( 10 - 20 ) days, and the median time between onset symptom and development of RM was 29 ( 22 - 40 ) days. The causes of RM included infection and status epilepticus ( 3 cases), and persistent involuntary movement ( 1 case). One patient recovered well after receiving steroid and intravenous immunoglobulin treatment and hydration and alkalization therapy. The other 3 patients with complicated infection and status epilepticus had poor response to the treatment and received plasma exchange and continuous hemofiltration. One died of septic shock, and 2 received rituximab treatment. One recovered well, while the other one had severe neurological sequelae. Conclusion Children with anti-NMDAR encephalitis can be complicated with RM. Patients in critical condition may have poor response to first-line immunotherapy and hydration and alkalization therapy, and blood purification therapy should be initiated in time.

Key words: anti-N-methyl-D-aspartate-receptor encephalitis; rhabdomyolysis; child