Tonic-clonic Seizure
The tonic-clonic seizure is the most common type of generalised seizure, occurring in 25% of all patients with seizures. Tonic-clonic seizures have two stages. The first stage is the tonic phase, during which the person loses consciousness and experiences sudden muscle contractions, causing them to fall. During the clonic phase, rapid jerking of the arms and usually the legs occurs. Tonic seizures usually last between three seconds and two minutes.
Myoclonic Seizure
A myoclonic seizure is a sudden and brief twitch or jerk of the body that typically occurs without warning. These seizures typically last less than a second and the person usually stays awake during them. Some people can also have them in clusters of several seizures over a period of time.
Clonic Seizure
Similar to the myoclonic seizure, the clonic seizure involves sudden and repeated jerking movements of the arms and legs. However, a clonic seizure usually lasts longer (around 1-2 minutes).
Absence Seizure
An absence seizure causes a person to lose awareness of their surroundings momentarily. A person experiencing an absence seizure may appear to stare blankly into space for a few seconds and then return to their original state. Absence seizures are more common in young people and generally do not result in any long-term issues.