See also:

• Seizure—Child

Definition

A seizure happens when there is certain types of abnormal electrical activity in the brain. During a seizure, you may:

• Lose consciousness
• Stare into space
• Have convulsions (abnormal jerking of the muscles)
• Experience abnormalities of sensation or emotion

When two or more seizures occur, it is considered a seizure disorder. This condition is also known as epilepsy.

Seizure disorders may be classified by the part of the brain they affect and the kinds of symptoms they cause. The main categories are:

• Generalized seizure disorder—thought to arise throughout the brain, not from a single focal location
• Partial seizure disorder (focal seizure)—caused by more localized abnormalities; happens within certain areas of the brain; may spread throughout the brain and become generalized

Brain Cells (Neurons)

© 2009 Nucleus Medical Media, Inc.

Causes

Seizures are caused by abnormal brain function. Seizure disorders can start at any age.

For most people, it is not known what causes the malfunction. Some known causes include:

• In newborns:
  • Congenital brain abnormalities (present at birth)
  • Birth injuries that deprive the brain of oxygen
  • Metabolic disorders
  • Maternal drug use
  • Infection
• In infants and children:
  • Febrile seizure —caused by spike in fever in a baby or very young child
  • Brain tumor
  • Infections ( encephalitis , cerebritis, brain abscess)
• In children and adults:
  • Congenital conditions
  • Genetic
  • Head trauma—common cause (eg, concussion , skull fracture , oxygen deprivation due to near-drowning )
  • Infections (eg, encephalitis , cerebritis, brain abscess)
  • Stroke
  • Brain tumor
• In elderly:
  • Stroke
  • Trauma
  • Brain tumor
  • Degenerative diseases (eg, Alzheimer’s disease )

Risk Factors

The following factors increase your chance of developing some seizure disorders:

• Previous brain injury—seizure disorder usually develops within one year of injury
• Previous brain infection
• Brain tumor
• History of stroke
• History of complex febrile seizures
• Use of certain medications or recreational drugs
• Stopping the use of medications, recreational drugs , or alcohol
• Drug overdose
• Exposure to toxins (eg, arsenic , lead , or carbon monoxide )
• Family history of seizure disorders
• Alzheimer’s disease
• Toxemia during pregnancy
• Chemical abnormalities (decreased or excess blood sodium or glucose, low blood calcium)
• Liver or kidney failure
• Severe, untreated high blood pressure
• Chronic diseases (eg, lupus , polyarteritis nodosa , porphyria , sickle cell disease , Whipple’s disease )
• Syphilis

If you already have a seizure disorder, the following factors can increase your chance of having a seizure:

• Sleep deprivation
• Alcohol
• Hormonal changes (such as those that occur at points during the menstrual cycle)
• Stress
• Flashing lights, especially strobe lights
• Use of certain medicines
• Missing doses of anti-epileptic medicines

Symptoms

There are many kinds of seizure disorders with a variety of symptoms, such as:

• Aura—a sensation at the start of a seizure, may involve the perception of an odd smell or sound, spots appearing in front of the eyes, or unusual stomach sensations; an aura is a seizure
• Staring
• Loss of consciousness
• Repeated jerking of a single limb
• Generalized convulsion, with uncontrollable jerking of muscles throughout the body
• Hand rubbing
• Lip smacking
• Picking at clothing
• Perception of an odor, sound, or taste
• Loss of bladder or bowel control
• Postictal state—a state of drowsiness, alteration in responsiveness, and/or confusion that commonly occurs after a generalized tonic-clonic seizure; may last minutes, hours, or days

Symptoms of generalized seizure disorders include:

• Generalized tonic-clonic seizures—loss of consciousness, uncontrollable jerking of muscles throughout the body
• Absence seizures—staring, eye blinking, or eye rolling

Symptoms of partial seizure disorder include:

• Complex partial or temporal lobe seizures:
  • May lose contact with reality, stop purposeful activity, and begin a series of automatic gestures (eg, lip smacking, hand-wringing, or picking at clothing)
  • May appear as a brief moment of confusion or loss of attentiveness
  • May have a perception of unusual sights, sounds, or smells
• Simple partial seizures:
  • Does not involve a loss of contact with reality or a loss of consciousness
  • Single area of the body may move uncontrollably (eg, leg or arm shaking)
  • May include the perception of an odor, sound, or taste, or an unrelated emotion

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may need to see a neurologist. These doctors specialize in the nervous system and brain.

Tests may include the following:

• Blood tests—to look for abnormal levels of different substances in the blood
• Electroencephalogram (EEG)—a test that uses sensors to evaluate electrical brain activity.
• MRI scan —a test that uses magnetic waves to make pictures of structures inside the brain
• CT scan —a type of x-ray that uses a computer to make pictures of structures inside the head (used in some cases)
• Lumbar puncture —a test of the cerebrospinal fluid (CSF) from the lower back; may be done to look for infection or bleeding
• Magnetoencephalography (MEG)—an imaging device that measures the brain's magnetic fields

Treatment

The goals of treatment are to:

• Treat the underlying cause (if known)
• Prevent seizures—may be done through medicine, surgery, or special therapies
• Avoid factors that stimulate seizure activity

Prevention

There are no known ways to prevent every type of seizure disorder. You can take steps to prevent brain injuries which could lead to seizures:

• Always wear a helmet when using bikes, rollerblades, skateboards, or scooters.
• Wear protective headgear when playing contact sports.
• Dive in safe depths of water.
• Always wear a seatbelt.
• Avoid using street drugs.
• If your baby or child has a high fever, get treatment right away.
• Get prenatal care. If you have high blood pressure during pregnancy, get proper treatment.
• If you have a chronic condition, get proper care.

If you have a very severe seizure disorder, some changes may be needed to prevent serious injuries, such as:

• Depending on your condition, avoid driving.
• Do not swim or bathe alone.
• Do not work on ladders or ledges.
• Avoid or modify athletic activities.

Talk to your doctor about these kinds of issues.