What is catastrophic epilepsy? Catastrophic epilepsy is epilepsy with early onset and high seizure frequency, and seizures so severe that they cause severe damage to the patient’s mental and motor development and even the course of daily life. This type of epilepsy is usually characterized by neurodevelopmental stagnation or even dramatic regression of the patient, which can lead to disability (loss of function of arms and legs), dullness, and difficulty living independently. In general, children under 6 years of age who still have more than 10 episodes/month after various treatments have a tendency to develop catastrophic epilepsy, and once the child develops reduced motor and language functions (e.g., a child who would call his or her mother and father cannot call them, can eat by himself or herself, and does not know how to use a spoon after a seizure), it indicates that catastrophic consequences may be difficult to avoid if other effective measures are not taken. Is catastrophic epilepsy more serious than intractable epilepsy? Catastrophic epilepsy is a disease with more serious consequences than intractable epilepsy. When intractable epilepsy occurs in children aged 0-6 years (the most critical period of brain development), it can cause catastrophic epilepsy; usually intractable epilepsy causes lower than normal intelligence, while catastrophic epilepsy regresses intelligence to the point of loss of motor function and inability to care for oneself. This is the reason why such refractory epilepsy is called “catastrophic epilepsy”.