A complex partial seizure is a type of seizure that arises in one lobe of the brain, rather than the whole brain. There are numerous possible symptoms. The seizure affects people’s awareness and may cause them to lose consciousness.

Complex partial seizures are now more commonly referred to as focal onset impaired awareness seizures or focal impaired awareness seizures.

Anybody can have a complex partial seizure, although people who have experienced head injuries, strokes, or tumors in the brain are more at risk.

Fast facts on complex partial seizures:

  • This form of seizure is the most common type experienced by people with epilepsy.
  • The symptoms are diverse and can vary from one seizure to another.
  • Seizure first aid focuses on keeping the person safe and comfortable.
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Common symptoms of complex partial seizures include:


Seizures are often preceded by an aura, known as a simple partial seizure. Auras usually last just a few seconds.

According to Johns Hopkins Medicine, an aura is a warning sign. These signs take on different forms.

For example, some people may have a feeling of fear, while others may get a strange sensation in their bodies, an unusual taste in their mouth, or hear a particular sound.

Impaired consciousness

People who have a complex partial seizure are not usually aware of their surroundings while it happens.

They will not respond to others or their environment, and they do not typically remember what occurs during the episode. They may stare blankly into space, appear to be daydreaming, or wake from sleep suddenly.

In some cases, the person will “freeze,” which is called a focal impaired awareness behavior arrest seizure.


In addition to an aura and impaired consciousness, many people also carry out repetitive movements, called automatisms. Examples of automatisms include:


  • crying
  • laughing
  • moaning
  • repetitive speech
  • screaming


  • chewing
  • lip smacking
  • swallowing


  • fumbling
  • head rolling
  • patting
  • picking at things
  • removing clothing
  • walking
  • coordinated movements, such as cycling of the legs or a swimming motion

Symptoms usually last from 30 seconds to 3 minutes.

Complex partial seizures that begin in the frontal lobe tend to be shorter than seizures originating in the temporal lobe.

After the seizure, the person will be fatigued, disoriented, and confused. Although these after-effects only last for approximately 15 minutes, many people are unable to function normally for several hours.

Complex partial seizures are usually caused by epilepsy, although they can be experienced by anyone. Other conditions that may cause seizures include:

Frequently, the cause of seizures is unknown.

Seizure triggers

Complex partial seizures tend to come on without much warning, the exception being when a person has an aura. Some common factors that can trigger a seizure include:

  • fatigue
  • fever
  • flashing lights
  • intense activity
  • loud noises
  • low blood sugar or hypoglycemia
  • reactions to medications
  • stress
  • strong emotions, such as anger or anxiety

Before implementing a treatment plan, a medical diagnosis is necessary. To diagnose complex partial seizures, a doctor may carry out one or more of the following:

Medical history

The doctor will look for details of what happens before, during, and after a seizure.

People typically cannot remember their seizures. Due to the changes in brain activity, memory is usually impaired.

As a result of this, a doctor will often ask for input from someone who has observed one or more seizures in the individual.

Electroencephalogram (EEG)

This diagnostic test assesses electrical activity in the brain. Even if a normal result is obtained from the EEG, it does not rule out epilepsy or complex partial seizures. Sometimes, for greater accuracy, the test will need to be carried out again during a seizure.

Imaging tests

A CT (computed tomography), an MRI (magnetic resonance imaging), or both, may be carried out to uncover potential causes of seizures.

Laboratory tests

Blood or urine may be tested to check for electrolyte levels, drug use, and concentrations of antiepileptic drugs if they have been prescribed. These tests can often reveal the underlying cause of the seizures.

Treatment plans for people with complex partial seizures are based on individual symptoms, diagnosis, and, in some cases, the presence of other medical conditions. Treatment options include:

Antiepileptic drugs

Medication, such as antiepileptic drugs or AEDs, is generally the first line of treatment considered for people with epilepsy and seizures.

Many people respond well to medication, which can prevent future seizures or at least decrease their frequency and intensity.

Some people will experience benefits from a single medication, while others may require a combination of AEDs.

After being seizure-free for a few years, many individuals can discontinue their medications.

However, at least 30 percent of people do not respond to AEDs.

Dietary changes

Dietary therapy can help to control seizures and is typically used in combination with AEDs.

A high-fat, low-carbohydrate diet, such as the ketogenic diet, is considered most effective. It is important that dietary changes for seizures are implemented and overseen by a doctor or dietitian, or both.

Responsive neurostimulation (RNS)

In 2013, the United States Food and Drug Administration (FDA) approved responsive neurostimulation for seizures.

RNS involves placing a device in the bone around the brain to monitor brainwaves for unusual electrical activities. If these are detected, the device will emit pulses of stimulation to return brainwaves to normal, therefore avoiding a seizure.

According to 2015 research, early reports indicate that RNS therapy cuts seizure frequency in half after 2 years of use, and is well-tolerated by users.

Vagus nerve stimulation

This treatment involves implanting a device in the chest, which is wired to the vagus nerve in the neck. The device sends bursts of energy to the brain to inhibit seizures.

Research suggests that vagus nerve stimulation reduces seizures by 50 percent or more in half of study participants, although 25 percent of users do not experience treatment benefits. Most people still require medication in conjunction with this treatment.


If other treatments do not help control seizures, surgery may be considered to remove the part of the brain that is causing the seizures. Surgery is carried out in cases where:

  • seizures begin in a small portion of the brain only
  • the area does not affect speech, language, motor function, vision, or hearing

As all surgeries carry risks, it is important for a person to discuss the risks and benefits of surgery with a doctor thoroughly before treatment.

Making the person calm and comfortable is the most important thing to do. This is especially important in public areas because some people who experience complex partial seizures may walk out in front of traffic or remove items of clothing.

Other actions to take would be to roll the individual on to their side and protect their head from injury by placing something soft underneath. It is helpful to time the seizure in case the episode is prolonged, and medical care is necessary.

As untreated seizures can lead to complications, such as injury or memory impairment, it is important to consult a doctor about seizure episodes, especially if:

  • it is someone’s first ever seizure
  • the seizure lasts for 5 minutes or longer
  • the person has a fever, diabetes, or may be pregnant
  • the person does not regain consciousness after the seizure

If the person has a rescue treatment, it should be administered to them. A rescue treatment is a medication that is taken, as necessary, to respond to seizures.

The outlook for a person with complex partial seizures depends on the cause, the area of the brain where they start, and the treatment the person receives.

Children can outgrow seizures, and both children and adults can often successfully manage their seizures with a range of treatments, including medication and dietary changes.

Therefore, it is essential to consult a doctor if seizures are experienced to get a diagnosis and access to treatments.