Severe anti-NMDA receptor encephalitis in a pediatric patient presenting with status dystonicus as the primary clinical manifestation: A case report (CARE).

RATIONALE: Anti-NMDAR encephalitis is the most prevalent form of autoimmune encephalitis, and status dystonicus may occur during the acute phase. Status dystonicus is a severe and rare acute movement disorder characterized by clinical manifestations resembling those of status epilepticus. However, there are currently limited case reports regarding anti-NMDAR encephalitis complicated by status dystonicus in pediatric patients. In this study, a pediatric patient with severe anti-NMDAR encephalitis developed status dystonicus during the acute phase. Symptoms gradually resolved following continuous intravenous infusion of midazolam.

PATIENT CONCERNS: The patient was admitted to our hospital for detailed evaluation due to abnormal emotions, involuntary movements, and language impairment. Following admission, the patient developed seizures, impaired consciousness, cognitive dysfunction, and status dystonicus. Abnormal results were found in the electroencephalogram and cerebrospinal fluid tests, and the anti-NMDAR antibody was positive.

DIAGNOSES: The child was diagnosed with severe anti-N-methyl-D-aspartate receptor encephalitis, presenting primarily with state dystonicus.

INTERVENTIONS: The child received immunotherapy including immunoglobulin, methylprednisolone pulse therapy, and rituximab. When status dystonicus occurred, continuous intravenous infusion of midazolam was administered, resulting in resolution of the symptom.

OUTCOMES: Electroencephalography can effectively differentiate status dystonicus from status epileptic.Continuous intravenous infusion of midazolam can alleviate status dystonicus.

LESSONS: During the acute phase of anti-NMDAR encephalitis, pediatric patients may develop status dystonicus. Neurologists should promptly distinguish it from status epilepticus and implement appropriate management strategies to improve patient outcomes.