ObjectiveTo summarize the clinical phenotype, electrophysiological characteristics, imaging characteristics, surgical treatment and prognosis of Rasmussen encephalitis (RE), so as to deepen the understanding of the disease. MethodsThe clinical data of patients with RE who underwent surgical therapy from October 2014 to October 2019 at Children's Epilepsy Center in Peking University First Hospital were retrospectively reviewed. Demographic characteristics, seizure forms, electroencephalogram (EEG), cranial nuclear magnetic resonance (MRI), operative methods as well as surgical outcomes evaluated by Engel classification during follow-up of the subjects were collected and analyzed. ResultsTotally 21 pediatric patients were enrolled, including 8 males and 13 females. The age at onset was (5.0±2.0) years old, the age at the time of surgery was (6.9±2.7) years old, and the disease duration at the time of surgery was (1.7±1.3) years. Twenty (20/21, 95.2%) patients had focal motor seizures, and 10 (10/21, 47.6%) patients had 2 or 3 forms of focal motor seizures. Fifteen patients (15/21, 71.4%) had epilepsia partialis continua (EPC), which occurred (0.7±0.6) years after the onset. All patients had hemiplegia, which appeared at (0.9±0.6) years after the onset. All patients showed a slow rhythm at their affected hemispheres during the EEG monitoring and 4 of them also showed slow rhythm at the contralateral hemispheres as the disease progressed. All patients had epileptiform discharges at the involved hemisphere, and 6 patients also had independent epileptiform discharges on the contralateral side. All 21 patients underwent hemispheric disconnection. The duration of follow-up was 2 to 7 years, and all patients achieved Engel class I after the surgery. The neurological dysfunction recovered to varying degrees during the postoperative period. ConclusionRE mostly occurs around the school age. Focal motor seizures are the main manifestations and the most common onset symptoms. With the progress of the disease, the condition of patients worsened gradually. The EEG of patients was mainly characterized by broad slow wave and spike wave in the affected hemisphere. Some patients can also have bilateral involvement, which was obviously asymmetrical. Through surgical treatment, the patients all achieved good results in terms of seizures and development.