When an epileptic seizure starts in one side of the brain, it’s called a focal onset seizure or a focal seizure. Both terms mean the same thing. Until recently these seizures were called partial seizures.
What are the main types of focal seizure?
There are 2 main types of focal seizure.
Focal aware seizures
During a focal aware seizure, you stay fully aware of what’s happening around you. This type of seizure used to be called a simple partial seizure.
Focal impaired awareness seizures
If your awareness of what’s happening around you is affected at any time during your seizure, it’s called a focal impaired awareness seizure. This type of seizure used to be called a complex partial seizure.
What happens during a focal seizure?
What happens to you during a focal seizure depends on which part of the brain the seizure happens in. This is because different areas of the brain control movements, body functions, feelings and reactions. Some people experience just one symptom during a focal seizure, while others experience several.
The symptoms of focal seizures can be split into 2 groups. Symptoms that involve movement are called motor symptoms. Symptoms that don’t involve movement are called non-motor symptoms. Here are some examples:
How long do focal seizures last?
Most focal aware seizures are brief, lasting between a few seconds and 2 minutes. Focal impaired awareness seizures usually last between one and 2 minutes.
What happens after a focal seizure?
What happens after a focal seizure varies from person to person. You might feel fine after a focal seizure and be able to get back to what you were doing straight away. Or you might feel confused or tired for some time afterwards. You might need to sleep.
Some people find they have temporary weakness or can’t move part of their body after they’ve had a seizure. This is called Todd’s paresis or Todd’s paralysis. It can last from a few minutes up to 36 hours, before going away.
How can someone help me during a focal seizure?
You might not need any help from people around you during a focal seizure, especially if it’s brief and you’re aware of what’s happening. But if you’re not aware of what you’re doing you might need help to guide you away from danger and keep you safe. See our first aid information, or 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 Epilepsy Action's information quality standards.
- Updated July 2017To be reviewed July 2020