What are the types of generalized seizures?

Primary generalized seizures arise simultaneously in both cerebral hemispheres. They generally involve impairment of consciousness, but their manifestations can range from barely noticeable to a tonic-clonic convulsion.

Sometimes it is difficult to distinguish primary generalized seizures from secondarily generalized seizures that are preceded by a very brief simple partial seizure, especially since the patient may have no memory of it.

Types of generalized seizures include:

Absence
Myoclonic
Clonic
Tonic
Tonic-clonic
Atonic

Adapted from: Holmes GL. Classification of seizures and the epilepsies. In: Schachter SC, Schomer DL, eds. The comprehensive evaluation and treatment of epilepsy. San Diego, CA: Academic Press; 1997. p. 1-36.
With permission from Elsevier (www.elsevier.com)
Reviewed and revised January 2004 by Gregory L. Holmes, MD, Dartmouth Medical School