Myoclonic seizures are also called myoclonic jerks. They can be generalised onset, meaning both sides of the brain are affected from the start, or they can be focal onset, meaning just one side is affected.
What happens during a myoclonic seizure?
Myoclonic seizures are sudden, short-lasting jerks that can affect some or all of your body. They are usually too short to affect your consciousness. The jerking can be very mild, like a twitch, or it can be very forceful. Sometimes if the jerk is very forceful it can make you throw something you’re holding, or make you fall over.
How long do myoclonic seizures last?
Myoclonic seizures usually only last for a fraction of a second. However, some people have them in clusters of several seizures over a period of time.
What happens after a myoclonic seizure?
After a myoclonic seizure you’re usually able to get back to what you were doing straight away.
How can someone help me during a myoclonic seizure?
Ask them to take our short online course which shows them what to do when someone has a seizure.
See this information with references
If you would like to see this information with references, visit the Advice and Information references section of our website. If you are unable to access the internet, please contact our Epilepsy Action Helpline freephone on 0808 800 5050.
Epilepsy Action would like to thank Professor Helen Cross, The Prince of Wales’s Chair of Childhood Epilepsy and Honorary Consultant in Paediatric Neurology at UCL Institute of Child Health and Great Ormond Street Hospital for Children, for her contribution to this information.
Professor Cross has declared no conflict of interest.
This information has been produced under the terms of The Information Standard.
- Updated July 2017To be reviewed July 2020