Focal epilepsy involves recurrent focal seizures, which affect only one area of your brain. These seizures tend to be less severe than seizures that affect both sides of your brain.

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Epilepsy is a neurological condition that affects about 3 million adults and 470,000 children in the United States. Healthcare professionals might diagnose epilepsy if someone has two or more seizures that don’t have a known cause, such as a high fever or medication side effects.

Focal epilepsy is the most common type of epilepsy. People with this type of epilepsy experience focal seizures, which may or may not cause them to lose consciousness. Some research suggests that focal seizures affect up to 61% of people with epilepsy.

In this article, we take a deeper look at focal epilepsy, including its symptoms, causes, and treatments.

Focal epilepsy involves recurrent seizures that are mainly focal seizures. It’s the most common form of epilepsy in both children and adults. Roughly two-thirds of epilepsy cases that develop in childhood are focal epilepsy.

During focal seizures, you may be aware or may have impaired awareness. Aware focal seizures affect only one area of your brain and don’t cause loss of consciousness. Impaired awareness focal seizures affect a larger section of your brain and cause loss of consciousness.

Focal aware seizures occur in 6–12% of people with epilepsy, and impaired awareness focal seizures occur in about 36%.

A seizure is an uncontrolled burst of electrical information in your brain that can cause symptoms such as:

Epilepsy involves recurring seizures. To receive a diagnosis of epilepsy, you must have at least two unprovoked seizures occurring more than 24 hours apart or one seizure with a high likelihood of having another.

Epilepsy can cause focal aware or focal impaired awareness seizures.

You don’t lose consciousness during focal aware seizures. They tend to last less than 2 minutes. During this time, you may feel like you’re frozen and be unable to respond to other people.

Symptoms depend on where in your brain the seizure begins, but they can include:

  • changes in senses such as taste and smell
  • muscle twitching
  • eye movements
  • a strange feeling going through your head
  • numbness or tingling in your limbs
  • a feeling that your arm or leg is smaller than usual
  • hallucinations
  • a feeling of déjà vu
  • sudden, intense fear or joy
  • the sensation of seeing flashing lights

If you have an impaired awareness seizure, your consciousness will be affected. You may be able to hear people but not fully understand what they’re saying or be able to respond.

Symptoms might include:

  • a blank stare
  • lip-smacking
  • eyelid fluttering
  • chewing
  • hand or finger movements
  • laughing
  • crying
  • screaming
When is a seizure an emergency?

Most seizures don’t require emergency medical attention. But the Centers for Disease Control and Prevention recommends seeking emergency attention if you or somebody you’re with:

  • has a seizure for the first time
  • has an underlying condition such as diabetes, heart disease, or pregnancy and experiences a seizure
  • has a seizure in water
  • sustains an injury during a seizure
  • has a second seizure shortly after the first
  • experiences a seizure lasting longer than 5 minutes
  • has trouble breathing after a seizure

The exact cause of focal epilepsy is often not known. Potential causes include:

Doctors cannot diagnose epilepsy by performing just one test. They make the diagnosis by asking you about your personal and family medical history and performing tests such as:

In addition to tests used to help diagnose focal epilepsy, healthcare professionals may use the following tests to plan treatment options such as surgery:

  • positron emission tomography (PET) scan
  • single photon emission computed tomography (SPECT) scan
  • intracranial monitoring, which involves inserting electrodes into your brain

Antiseizure medication

Antiseizure medications are the primary treatment for focal epilepsy. These medications are effective at treating seizures in about 70% of people with epilepsy. Many antiseizure medications are available, and you may have to try several types before finding one that works.

Surgery

People who don’t have improvement in their seizures after trying at least two antiseizure medications might benefit from surgery. The most common surgery to treat focal epilepsy involves removing part of your:

  • temporal lobe
  • hippocampus
  • amygdala

This procedure has success rates of 60–70%.

Ketogenic diet

Some children who don’t respond to antiseizure medications see improvement after adopting a ketogenic diet, which involves restricting carbohydrates.

Neuromodulation

Neuromodulation involves using medical devices to stimulate nerves that affect areas of your brain involved in seizure activity. Types of neuromodulation include:

First aid is usually not needed for focal seizures since they don’t typically cause loss of consciousness. Ways you can help someone who is having a focal seizure include:

  • removing harmful objects
  • keeping them away from flames, bodies of water, and unsafe areas
  • helping them sit down to avoid falling
  • stopping activities that could lead to injury

In North America, epilepsy is more common among ethnic minorities and people of lower socioeconomic status. These disparities might happen because people in those populations are more likely to have difficulty accessing healthcare.

Epilepsy also affects males slightly more often than females.

Focal epilepsy is most common among children and adults over 65 years old. The most common type, benign Rolandic epilepsy, usually occurs between the ages of 5 and 10 years.

Focal epilepsy often has a good outlook when treated with medications or surgery. Focal seizures have a lower chance of causing injury than generalized seizures, which involve both sides of your brain.

Many children with focal epilepsy outgrow it and remain seizure-free throughout their lives. On average, children with focal epilepsy have an 80% reduction in seizure activity over 7 years.

Can you have a high quality of life with focal epilepsy?

Many people with focal epilepsy can have a high quality of life with medications. Many people whose epilepsy doesn’t respond to medications experience improvements with surgery.

What does focal epilepsy feel like?

Focal epilepsy can feel different from person to person, depending on which part of the brain is affected. People often describe:

  • experiencing muscle stiffness
  • seeing flashing lights
  • feeling numbness or tingling in their limbs

Will I lose consciousness during my seizures?

You will stay conscious during focal aware seizures but lose consciousness during focal impaired awareness seizures.

Focal epilepsy involves repeated focal seizures that affect only one area of your brain. It’s the most common type of epilepsy in adults and children.

Many people with focal epilepsy experience seizure relief with medications. You may need to try several types of medication before finding one that works for you.