Seizure Disorders - Adult



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:

  • Stroke
  • Head trauma
  • Alcohol use disorder
  • Degenerative diseases, such as Alzheimer disease
  • Brain damage
  • Brain tumors
  • Infections, such as bacterial meningitis
  • Genetic problems
  • Problems with the immune system

Risk Factors

Things that may raise the risk of this disorder are:

  • Cerebrovascular disease in older adults
  • Parasitic diseases, such as malaria or cysticercosis
  • Alcohol use disorder



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


You will be asked about your symptoms and health history. A physical exam will be done. You may need to see a doctor who treats the nervous system and brain.

Blood tests may be done.

Brain activity may be tested. This can be done with an electroencephalogram (EEG).

Images may be taken. This can be done with:

  • MRI scan
  • CT scan
  • Positron emission tomography (PET)
  • Single photon emission computed tomography (SPECT)



The goals of treatment are to:

  • Treat any underlying cause
  • Prevent seizures—may be done through medicine, surgery, or special therapies
  • Avoid seizure triggers


Anti-seizure medicines may be given. More than one may be needed.


Surgery may be needed in people who are not helped by medicine. It will be done to remove the part of the brain that starts the seizures. It is only an option for people who have seizures that affect specific parts of the brain.

Implanted Devices

Devices may be implanted to manage seizures. Some may be used with medicine. These are:

  • 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

In some people, following a strict diet that is rich in fats and low in carbohydrates and protein may reduce seizures. This is called a ketogenic diet. It is not known why it helps. . It is more helpful in children than adults.

Avoiding Triggers

Avoiding seizure triggers may help some people. The triggers my differ from person to person. Some triggers may be:

  • Lack of sleep
  • Flashing bright lights
  • Excessive alcohol use
  • Drug use
  • Stress
  • Avoid driving, if advised to do so by your doctor.
  • Do not swim or bathe alone.
  • Do not work on ladders or ledges.
  • Avoid or modify athletic activities.


The risk of seizure disorder may be lowered by:

  • Preventing brain injuries by:
    • Wearing a seatbelt
    • Wearing a helmet when using motorcycles, bikes, rollerblades, skateboards, or scooters
    • Wearing the right equipment when playing contact sports
    • Diving in safe depths of water
  • Taking steps to avoid parasitic infection, such as using proper hand hygiene and food preparation

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.

a (Epilepsy—Adult)

See also:

  • Seizure—Child
  • Seizure Disorder—Child


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.