by EBSCO Medical Review Board


A seizure is sudden and abnormal electrical activity in the brain. A seizure disorder is when a person has two or more seizures that are not due to illness or another trigger. This is also known as epilepsy.

Seizures are classified into two groups:

  • Generalized seizure disorder—affects both sides of the brain
  • Partial seizure disorder (focal seizure)—affects only one area of the brain
Brain Cells (Neurons)
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Seizures happen because of abnormal brain activity. For many people, it is not known why this happens. Some known causes are:

Risk Factors

Things that may raise the risk of this disorder are:


Symptoms depend on the type of seizures that a person has.

Generalized seizures may cause:

  • Eye blinking or staring into space
  • Crying out
  • Loss of consciousness
  • Falling to the ground
  • Muscle jerking or spasms
  • Feelings of tiredness after the seizure has ended

Partial seizures may cause:

  • Muscle twitching
  • Sensing a strange taste or smell
  • Confusion or a dazed feeling
  • Inability to respond to questions or directions


The doctor will ask about symptoms and past health. A physical exam will be done. An appointment with a doctor who treats the nervous system and brain may be needed.

Brain activity may be tested. This can be done with an electroencephalogram (EEG). Images of the brain may be taken with:


The goals of treatment are prevent further seizures with fewest side effects. This may mean treating an underlying cause or avoiding triggers.


Anti-seizure medicines may be given. More than one may be needed. It may take some time to find the right medicine and dosage.

Implanted Devices

Devices can help to interrupt signals that cause seizures. They are placed just under the skin and attached to brain or large nerve. The devices may be used alone or with medicine. Implanted devices include:

  • Vagus nerve stimulation (VNS)—implanted in the chest to stimulate the vagus nerve to decrease seizures
  • Responsive nerve stimulator (RNS)—implanted in the brain to detect and stop seizures
  • Deep brain stimulation (DBS)—implanted in the brain and attached to a device implanted in the chest to stop signals that trigger a seizure

Ketogenic Diet

A ketogenic diet is a strict diet that is low in carbohydrates and rich in fats. For some people, this diet may reduce seizures. It is not known why it helps.

This diet is very strict and may be hard to stick to. Other low carbohydrate diets like Atkins or low glycemic diet may have some benefit.

Avoiding Triggers

Learning and avoiding triggers can help some. Triggers can differ from person to person. Some common triggers are:

  • Lack of sleep
  • Flashing bright lights
  • Excessive alcohol use
  • Drug use
  • Stress


Surgery may be done for seizures that are not helped by medicine. The area that is causing the seizures will be removed or destroyed. It is only an option if the seizures start in one specific spot in the brain.


Most seizure disorders cannot be prevented.


Epilepsy Foundation 

National Institute of Neurological Disorders and Stroke 


Center for Epilepsy and Seizure Education 

Epilepsy Ontario 


Antiepileptic drugs (AEDs) for seizure disorders. EBSCO DynaMed website. Available at: Accessed January 27, 2021.

Epilepsy in Adults. EBSCO DynaMed website. Available at: Accessed January 27, 2021.

Geller EB, Skarpaas TL, Gross RE, et al. Brain-responsive neurostimulation in patients with medically intractable mesial temporal lobe epilepsy. Epilepsia. 2017;58(6):994-1004.

Serafini A, Lukas RV, VanHaerents S, et al. Paraneoplastic epilepsy. Epilepsy Behav. 2016;61:51-58.

Thijs RD, Surges R, et al. Epilepsy in adults. Lancet. 2019 Feb 16;393(10172):689-701.

Revision Information

  • Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
  • Review Date: 01/2021
  • Update Date: 01/28/2021