A child’s smile should be a comfort to parents, but the smile of Pengpeng, a 14-year-old boy, is a nightmare for his parents. Recently, at the Epilepsy Center of Sanbo Brain Hospital of Capital Medical University, it was determined that Pengpeng’s often cute smile from childhood was caused by seizures caused by a hypothalamic malformation tumor. At the age of 3, in addition to laughing, Peng Peng was also involuntarily scratching his head, twisting his head, and spinning his body around. This alerted his parents, who then diagnosed him with epilepsy at a local hospital and took anti-epileptic drugs. But the seizures had not been controlled for 13 years. In order to help their son completely get rid of his epilepsy, the family came to the Epilepsy Center of Sanbo Brain Hospital of Capital Medical University for medical treatment. After a detailed preoperative examination and evaluation, Pengpeng was diagnosed to have frequent epileptic seizures with a hypothalamic malformation tumor located in the midline area of the brain. This type of epilepsy caused by hypothalamic malformation tumor must be treated early in order to effectively control the seizures. Under the microscope, a peanut-sized malformation tumor was successfully removed from Pengpeng’s brain, and after the surgery, Pengpeng’s symptoms of dementia and epilepsy disappeared completely, and he became smart and clever. Hypothalamic malformation tumor is a rare brain developmental abnormality, the common clinical manifestations are mainly precocious puberty, seizures, mental retardation and behavioral abnormalities. The characteristic form of seizure is demented laughter seizure, which usually develops in infants and early childhood. Most patients have other forms of seizures besides demented laughter seizure, such as complex movement, disorientation, tonic seizure, clonic seizure, tonic clonic, etc. The first thing you need to do is to get a good idea of what you are getting into. If not detected for a long time and not treated effectively, the condition can easily worsen and develop into generalized seizures, even leading to regression of the child’s intelligence.