Tiêu cơ vân cấp – biến chứng hiếm gặp ở hai bệnh nhi mắc viêm não tự miễn kháng thụ thể N-Methyl-D-Aspartate

Abstract

We report two pediatric cases of anti-N-methyl-D-aspartate receptor (NMDAR) autoimmune encephalitis complicated by acute rhabdomyolysis. The first case was a 10s-year-old girl who initially presented with impaired consciousness, behavioral disturbances, and movement disorder. She was treated with high-dose methylprednisolone, intravenous immunoglobulin, and risperidone. On day 7 of hospitalization, she developed acute rhabdomyolysis with a serum creatine kinase (CK) level of 56,247 U/L, accompanied by urinary tract infection. The patient responded well to aggressive fluid replacement, urine alkalinization, and benzodiazepine for controlling movement disorder. At 6-month follow-up, she showed partial recovery with a modified Rankin Scale (mRS) score of 3. The second case was a 9-year-old boy who presented with movement disorder and seizures. He developed severe rhabdomyolysis with a CK level of 215,000 U/L, complicated by septic shock and acute kidney injury requiring continuous renal replacement therapy. Renal function recovered after treatment; however, he was left with neurological sequelae (mRS score 3 at 5-year follow-up). These cases highlight that acute rhabdomyolysis is a serious complication of anti-NMDAR autoimmune encephalitis, particularly in patients with worsening movement disorder following initial immunotherapy and concomitant infection. Early recognition and timely intervention are essential to prevent renal damage and improve prognosis.