1. Is the division of grand and petit mal seizures related to the convulsive movements? Both grand and petit mal seizures are generalized seizures. Major and minor seizures are not distinguished by the magnitude of the convulsive movements. A grand mal seizure has generalized twitching of the limbs, while a typical petit mal seizure has only a brief (no more than 1 minute) loss of consciousness and no convulsive movements. Some patients or family members identify all other forms of seizures other than generalized grand mal seizures as petit mal seizures, which is obviously inaccurate. Hao Yong, Department of Neurology, Shanghai Renji Hospital 2. What is primary epilepsy? In Western medical terminology, the term “primary” is often used for diseases for which no cause can be found, such as primary hypertension. Epilepsy is no exception. For patients with epilepsy who cannot find the cause of epilepsy, it is called “primary epilepsy”, also known as “idiopathic epilepsy”. With the advances in technology, such as CT and MRI, it has been found that these so-called “primary epilepsies” are caused by small benign tumors, cerebral infarcts, congenital malformations, or traumatic scarring, so the proportion of primary epilepsies is decreasing. The current clinical tendency is to refer to epilepsy with a high suspicion of a causative lesion but no structural brain abnormalities on cranial CT and MRI as cryptogenic epilepsy. Primary epilepsy mostly has its own characteristics, such as a more pronounced genetic predisposition, mostly starts in adolescents, seizure types are mostly tonic clonic seizures (grand mal) and akathisia seizures (petit mal), this type of epilepsy is also called hereditary or familial epilepsy, and is easier to control with the application of antiepileptic drugs. So today it is also diagnosed as a disease and has its own diagnostic criteria. 3. What is secondary epilepsy? Secondary epilepsy refers to epilepsy secondary to other diseases (e.g., multiple brain diseases or metabolic abnormalities), i.e., epilepsy caused by other diseases, also known as “symptomatic epilepsy”, which accounts for about 30%-40% of all epilepsy. Like primary epilepsy, secondary epilepsy has its own characteristics. Most of them start after young adulthood, most of the seizure types are limited seizures and psychomotor epilepsy, and they are not easily controlled by antiepileptic drugs until the cause is removed.