In January 2015, in the bright and spacious functional neurosurgery ward of Sanbo Brain Hospital of Capital Medical University, the clear voice of “The sun is over the mountains and the yellow river flows into the sea ……” came from Xiao Li, a Hunan child who recently underwent a hemispherectomy. The director of Sanbo Brain Hospital, Zhou Jian, reminded that hemispherectomy is used to treat hemispheric epilepsy with exact efficacy, and it is important to accurately predict the patient’s postoperative risk. Xiao Li is 6 years old and two years ago, she had blinking left eye, left skewed mouth, tonic clonus of left limb, blue lips and loss of consciousness for no apparent reason. Half a year later, she went to a hospital in Hunan Province, and after drug treatment, she was discharged seizure-free for one month, and half a month later, she had seizures again, and not only the number of seizures gradually increased, but also new forms of seizures appeared, and the effect of drug treatment was still not satisfactory. Soon afterwards, Xiao Li’s intelligence decreased significantly, and her left limb had poor fine activity and reduced movement and speech, so she came to Capital Medical University Sanbo Brain Hospital to seek further treatment. Director Jian Zhou found that Xiao Li’s brain tissue was characterized by progressive atrophy. Combining the medical history and EEG, he considered that the patient’s epilepsy was caused by an extremely rare form of encephalitis, RE encephalitis. On January 13, Director Zhou performed a right frontotemporoparietal craniotomy on Xiao Li, and the surgery went very well. After the surgery, the epilepsy disappeared and Xiao Li’s quality of life and intelligence improved significantly. Director Jian Zhou pointed out that hemispheric surgery is a very effective but risky and difficult surgery, so it is especially important to conduct a comprehensive preoperative evaluation, strictly grasp the indications for surgery, and accurately predict the benefits and risks of patients after surgery.