What Is a Complex Partial Seizure?

Medically Reviewed by Christopher Melinosky, MD on October 23, 2023
5 min read

Complex partial seizures, now called focal onset impaired awareness seizures, are the most common type for adults who have epilepsy (a disorder that affects your brain cells). They’re usually harmless and only last a minute or two. But they can be strange or worrying -- both for you and anyone who’s with you.
Seizures are brought on by surges of electrical energy in your brain. With a complex partial seizure, the surge happens only on one side and in a specific area. It’s called “partial” because only one part of your brain is affected.

During this type of seizure, you may not be able to control your movements or talk. Afterward, you may not remember at all.

Anyone can have a complex partial seizure, and doctors don’t always know why they happen. They’re often related to a type of epilepsy called temporal lobe epilepsy. They also may be more common in people who have had a stroke or head injury or who have other health problems, like an infection in their brain or a tumor.

The electrical surge of a complex partial seizure can cause different symptoms, depending on the part of your brain that’s affected.

For some people, the first sign is an aura. You might notice:

  • Strong emotions, like fear
  • Changes in your vision -- you might see colored lines or spots
  • Strange feelings or thoughts, like tingling or deja vu (the sense that you’ve been in the exact same situation before, even though you haven’t)
  • Commonly, a auditory hallucination (hearing a radio or something that isn't there)

During the seizure, you may suddenly stop what you’re doing and look off into space as if you’re daydreaming. But nothing will snap you out of it. You also may start to chew, smack your lips, mumble, or do other things over and over again. You may move in a stiff, mechanical way.

Some people pick at their clothes, as if they’re pulling off lint. They also may walk around, go up or down stairs, or even run. Others shout, take off their clothes, seem afraid, or move their legs as if they’re pedaling a bike.

Complex partial seizures usually last between 30 seconds and 2 minutes. Afterward, you may be confused and tired for 15 minutes or longer. You will not remember the seizure at all. You may lose memories from before the seizure started, too.

Your doctor will first want to confirm that you had a seizure and then figure out what kind it was. They’ll ask a lot of specific questions about what happened. If any family members were there when you had your seizure, bring them to your appointment so they can help describe what you were doing.

Your doctor may also do some tests:

  • Electroencephalogram (EEG): Special sensors are placed on your head and connected to a computer to measure and record your brain waves.
  • Computed tomography (CT) scan: Several X-rays are taken from different angles and put together to make a more complete picture of your brain.
  • Magnetic resonance imaging (MRI): Powerful magnets and radio waves make detailed images of your brain.
  • Blood test: Blood is drawn and tested for several factors to help determine the cause of the seizure.
  • Lumbar puncture: Fluid is drawn from your lower spine and tested to rule out possible infections in the central nervouse system.


This mainly depends on what works for you -- there’s no general treatment plan for complex partial seizures. If your child has these seizures, keep in mind that some kids outgrow them.

Some options include:

Medication: Common ones include antiepileptic medication. Your doctor will decide which one is most likely to help you.

Changes to your diet: A special diet -- like the high-fat and low-carb ketogenic diet -- may help prevent seizures in some people.

Surgery: If nothing else works, your doctor may recommend surgery to interrupt the signals that spread seizures from one part of your brain to another -- so it’s limited to a smaller part of your brain. In more serious cases, the part of the brain where the seizures start may be taken out or targeted with a laser.

Devices: A vagus nerve stimulator is like a pacemaker for your brain -- it sends mild electrical pulses to a nerve in your neck. Your doctor might recommend this if other treatments haven’t worked for you. There is also the neuropace device which is a reactive neurostimulator that detects seizures and stimulates the brain to stop them

If there’s a chance you’ll have more seizures, your doctor may suggest that you take care with certain things which culd cause bodily harm if you lose control of your body. due to a seizure Things such as climbing a ladder, driving or swimming alone.

If you’re with someone who’s having a complex partial seizure, your main goal is to help keep them safe. They might hurt themselves -- they could fall or walk into something, for example. Here’s what you can do:

  • Don’t try to hold them down unless it’s the only way to keep them safe. It usually won’t help and could injure both of you.
  • Talk to them quietly and calmly. Sometimes, people having this kind of seizure may be able to hear you and respond to basic commands.
  • Lead them to a safe place. Move them away from any objects that could hurt them. If the seizure started in a risky situation -- while they were in a pool, in traffic, up high, or near a hot stove -- guide them away.
  • Keep track of time. If the seizure lasts more than 5 minutes, call 911.

Stay with them and make sure they recover. Don’t leave during the seizure. If you know there’s a treatment they need to keep them from having more seizures or help them recover, follow the doctor’s instructions.