A seizure is the physical findings or changes in behavior that occur after an episode of abnormal electrical activity in the brain.

See also:

• Generalized tonic clonic seizure
• Partial (focal) seizure
• Petit mal (absence) seizure
• Epilepsy
• Fever (febrile) convulsions (seizures in children with high fever)

There are a wide variety of possible symptoms of seizures, depending on what parts of the brain are involved. Many, if not all, types of seizures cause loss of awareness and some cause twitching or shaking of the body.

However, some seizures may be hard to notice because they consist of staring spells that can easily go unnoticed. Occasionally, seizures can cause temporary changes in sensation or vision.

Symptoms of seizures come on suddenly, over just seconds to a minute, and may include:

• Change in consciousness, so that you can't remember some period of time
• Change in emotion, like unexplainable fear, panic, joy, or laughter
• Change in sensation of the skin, usually spreading over the arm, leg, or trunk
• Changes in vision, including flashing lights, or (rarely) hallucinations (seeing things that aren't there)
• Loss of muscle control and falling, often very suddenly
• Muscle movement such as twitching that might spread up or down an arm or leg
• Muscle tension/tightening that causes twisting of the body, head, arms or legs
• Tasting a bitter or metallic flavor

Symptoms may stop after a few minutes, or continue for 15 minutes. They rarely continue longer.

Shaking of the entire body when it occurs should last a few minutes and stop within 5 minutes.

A seizure may be related to a temporary condition, such as exposure to drugs, withdrawal from certain drugs, a high fever, or abnormal levels of sodium or glucose in the blood. If the repeated seizures do not happen again once the underlying problem is corrected, the person does not have epilepsy.

In other cases, injury to the brain (for example, stroke or head injury) causes brain tissue to be abnormally excited.

In some people, a problem that is passed down through families (inherited) affects nerve cells in the brain, which leads to seizures. In these cases, the seizures happen spontaneously, without an immediate cause, and repeat over time. This is epilepsy.

Idiopathic seizures are chronic seizures that occur without an identifiable cause. They usually begin between ages 5 and 20, but can occur at any age. The person can have a family history of epilepsy or seizures.

Other more common causes of seizures include:

• Tumors (such as brain tumor) or other structural brain lesions (such as bleeding in the brain)
• Traumatic brain injury, stroke, or a transient ischemic attack (TIA)
• Stopping alcohol after drinking heavily on most days
• Illnesses that cause the brain to deteriorate
• Dementia such as Alzheimer's disease
• Problems that are present from before birth (congenital brain defects)
• Injuries to the brain that occur during labor or at the time of birth
• Low blood sugar or sodium levels in the blood
• Kidney or liver failure
• Use of cocaine, amphetamines, or certain other recreational drugs
• Stopping certain drugs, such as barbiturates and benzodiazepines, after taking them for a period of time.
• Infections (brain abscess, meningitis, encephalitis, neurosyphilis, or AIDS)
• Phenylketonuria (PKU) can cause seizures in infants

If someone who has never had a seizure before had one, call 911 or your local emergency number immediately.

Persons with epilepsy should always wear a medical alert tag.

Most seizures stop by themselves. However, a person having a generalized seizure may be injured; breathe food, fluid, or vomit into the lungs; or not get enough oxygen. During a generalized seizure, it is important to protect the person from injury. Turn the person on the side, so that any vomit leaves the body and does not enter the lungs. See: Seizure first aid

After a generalized seizure, most people go into a deep sleep. Do not prevent the person from sleeping. The person will probably be disoriented, or possibly agitated for awhile after awakening.

EMERGENCY FIRST AID

• Do not attempt to force a hard object (such as a spoon or a tongue depressor) between the teeth. You can cause more damage than you can prevent.
• Do not try to hold the person down during the seizure.
• Turn the person to the side if vomiting occurs. Keep the person on his or her side while sleeping after the seizure is over.
• If the person having a seizure turns blue or stops breathing, try to position their head to prevent their tongue from blocking their airway. Breathing usually starts on its own once the seizure is over.
• CPR or mouth-to-mouth breathing is rarely needed after seizures and cannot be performed during the seizure.

If a person has repeated or prolonged seizures without regaining consciousness or returning to normal behavior, the body may develop a severe lack of oxygen. This an emergency situation - seek immediate medical help.

AFTER THE SEIZURE

Treat any injuries from bumps or falls. Record details of the seizure to report to the person's primary health care provider. You should note the following details:

• How long it lasted
• What body parts were affected
• Type of movements or other symptoms
• Possible causes
• How the person behaved after the seizure

If this is the first time someone has ever had a seizure, or if this is an unusually long seizure in someone who has a seizure disorder, call 911 or your local emergency number immediately. These symptoms can be caused by life-threatening conditions, such as a stroke or meningitis.

Report all seizures (even a mild one) to the health care provider. If the person is known to have epilepsy or recurrent seizures, their doctor should be notified so that medications can be adjusted or other instructions given.

Often, a person who has had a new or severe seizure will be seen in an emergency room, rather than a doctor's office.

The health care provider will try to diagnose the type of seizure based on the symptoms.

Other medical conditions that can cause a seizure or similar symptoms will be ruled out. Disorders that may cause similar symptoms include fainting, TIA or stroke, rage or panic attacks, migraine headaches, sleep disturbances, and conditions that cause loss of consciousness.

The following tests may be done:

• Blood tests
• CT scan of the head or MRI of the head
• EEG (usually not in the emergency room)
• Lumbar puncture (also called a spinal tap)

The need for further tests or treatment depends on a number of factors.

• A single seizure due to an obvious trigger (such as fever or a drug) is treated by eliminating or avoiding that trigger.
• A new seizure without an obvious trigger will require further testing and possible treatment.
• A seizure in a person with known epilepsy will require tests to make sure the patient is taking the correct dose of their medicines. A possible change in medicines may be needed.

Instructions for taking any prescribed medications should be strictly followed. Family members should observe and record any seizure information to make sure the person gets proper treatment.

Good health habits may help to control seizures. Because sleep deprivation, stress, and a poor diet can contribute to increased seizures, good sleep habits, stress reduction, proper exercise, and sound nutrition may help.

There is no specific way to prevent all seizures. Use helmets when appropriate to prevent head injury. This will lessen the likelihood of a brain injury and subsequent seizures. Avoid recreational drugs. People with epilepsy should take medication as directed and avoid excessive amounts of alcohol.

People with uncontrolled seizures should not drive. Each state has a different law that determines which people with a history of seizures are allowed to drive. People with uncontrolled seizures also should avoid activities where loss of awareness would cause great danger, such as climbing to high places, biking, and swimming alone.

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Krumholz A, Wiebe S, Gronseth G, et al. Practice parameter: evaluating an apparent unprovoked first seizure in adults (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2007;69(21):1991-2007.

Pollack CV Jr. Seizures. In: Marx, JA, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 6th ed. Philadelphia, PA: Mosby Elsevier; 2006: chap 100.

Spenser SS. Seizures and Epilepsy. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, PA: Saunders Elsevier; 2007: chap 426.