The initial clinical manifestations of generalized seizures suggest bilateral hemisphere involvement, which can be convulsive or non-convulsive, often accompanied by impaired consciousness; myoclonic seizures are of shorter duration and may be without impaired consciousness; motor symptoms are often bilateral, but not necessarily systemic, and may be absent. At the onset of the seizure, the electroencephalogram shows that neuronal discharges are widely diffused in both hemispheres. The clinical manifestations of various types of generalized seizures are quite characteristic, and the electroencephalogram has strong specificity and great differences. For example, regardless of the differences in clinical manifestations of absence seizures, the basic electroencephalogram changes of the seizures are all paroxysmal spike-slow wave discharges; although the electroencephalogram of atonic seizures can have a variety of manifestations during the attack, they all have a certain specificity.