Epilepsy is a brain disorder involving repeated, spontaneous seizures of any type. Seizures ("fits," convulsions) are episodes of disturbed brain function that cause changes in attention or behavior. They are caused by abnormally excited electrical signals in the brain.
See also: Seizures
Temporal lobe epilepsy; Seizure disorder
Causes, incidence, and risk factors:
Seizures ("fits," convulsions) are episodes of disturbed brain function that cause changes in attention or behavior. They are caused by abnormally excited electrical signals in the brain.
Sometimes a seizure is 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 seizure or seizures do not happen again once the underlying problem is corrected, the person does NOT have epilepsy.
In other cases, permanent injury to or changes in brain tissue cause the brain to be abnormally excitable. In these cases, the seizures happen without an immediate cause. This is epilepsy. Epilepsy can affect people of any age.
Epilepsy may be idiopathic, which means the cause cannot be identified. These seizures usually begin between ages 5 and 20, but they can happen at any age. People with this condition have no other neurological problems, but sometimes have a family history of seizures or epilepsy.
Some other more common causes of epilepsy include:
- Stroke or transient ischemic attack (TIA )
- Illnesses that cause the brain to deteriorate
- Dementia , such as Alzheimer's disease
- Traumatic brain injury
- Infections (including brain abscess , meningitis , encephalitis , neurosyphilis , and AIDS)
- Problems that are present from before birth (congenital brain defects)
- Injuries near the time of birth (in this case, seizures usually begin in infancy or early childhood)
- Kidney failure or liver failure
- Metabolic diseases that children may be born with (such as phenylketonuria )
- Tumors or other structural brain lesions (such as hematomas or abnormal blood vessels)
The severity of symptoms can vary greatly, from simple staring spells to loss of consciousness and violent convulsions. For most people with epilepsy, each seizure is similar to previous ones. The type of seizure a person has depends on a variety of things, such as the part of the brain affected and the underlying cause of the seizure.
An aura consisting of a strange sensation (such as tingling, smelling an odor that isn't actually there, or emotional changes) occurs in some people prior to each seizure.
For a detailed description of the symptoms associated with a specific type of seizure, see:
Signs and tests:
A physical examination (including a detailed neurologic examination) may be normal, or it may show abnormal brain function related to specific areas of the brain.
Persons with epilepsy will often have abnormal electrical activity seen on an electroencephalograph (EEG ). (An EEG is a reading of the electrical activity in the brain.) In some cases, the test may show where in the brain the seizures start. EEGs can often be normal in between seizures, so it may be necessary to perform a longer test.
Various blood tests and other tests to rule out temporary and reversible causes of seizures, may include:
Tests for the cause and location of the problem may include:
For treatment of seizures, please see Seizures - first aid.
If an underlying cause for recurrent seizures (such as infection) has been identified and treated, seizures may stop. Treatment may include surgery to remove a tumor, an abnormal or bleeding blood vessel, or other brain problems.
Medication to prevent seizures, called anticonvulsants, may reduce the number of future seizures. These drugs are taken by mouth.
- The type of medicine you take depends on what type of seizures you are having. The dosage may need to be adjusted from time to time.
- Some seizure types respond well to one medication and may respond poorly (or even be made worse) by others. Some medications need to be monitored for side effects and blood levels.
- It is very important that you take your medication on time and at the correct dose. Most people taking these drugs need regular checkups and regular blood tests to make sure they are receiving the correct dosage.
- You should not stop taking or change medications without talking to your doctor first.
Some factors increase the risk for a seizure in a person with epilepsy. Talk with your doctor about:
- Certain prescribed medications
- Emotional stress
- Illness, especially infection
- Lack of sleep
- Skipping doses of epilepsy medications
- Use of alcohol or other recreational drugs
Epilepsy that does not get better after two or three seizure drugs have been tried is called "medically refractory epilepsy."
- Some patients with this type of epilepsy may benefit from brain surgery to remove the abnormal brain cells that are causing the seizures.
- Others may be helped by a vagal nerve stimulator. This is a device that is implanted in the chest (similar to a heart pacemaker). This stimulator can help reduce the number of seizures, but rarely stops the seizures completely.
Sometimes, children are placed on a special diet to help prevent seizures. The most popular one is the ketogenic diet. A diet low in carbohydrates, such as the Atkins diet, may also be helpful in some adults.
Persons with epilepsy should wear medical alert jewelry so that prompt medical treatment can be obtained if a seizure occurs.
The stress caused by having seizures (or being a caretaker of someone with seizures) can often be helped by joining a support group. In these groups, members share common experiences and problems. See: Epilepsy - support group
In addition to groups that meet face-to-face, there are many discussion groups and bulletin boards on the Internet where people with epilepsy can find support.
Some people with certain types of seizures may be able to reduce or completely stop their seizure medicines after having no seizures for several years. Certain types of childhood epilepsy goes away or improves with age -- usually in the late teens or 20s.
For some people, epilepsy may be a lifelong condition. In these cases, the seizure drugs need to be continued.
Death or permanent brain damage from seizures is rare. However, seizures that last for a long time or two or more seizures that occur close together (status epilepticus) may cause permanent harm. Death or brain damage are most often caused by prolonged lack of breathing, which causes brain tissue to die from lack of oxygen. There are some cases of sudden, unexplained death in patients with epilepsy.
Serious injury can occur if a seizure occurs during driving or when operating dangerous equipment. For this reason, people with epilepsy whose seizures are not under good control should not do these activities.
People who have infrequent seizures may not have any severe restrictions on their lifestyle.
- Difficulty learning
- Inhaling fluid into the lungs, which can cause aspiration pneumonia
- Injury from falls, bumps, or self-inflicted bites during a seizure
- Injury from having a seizure while driving or operating machinery
- Many epilepsy medications cause birth defects -- women wishing to become pregnant should alert their doctor in advance in order to adjust medications
- Permanent brain damage (stroke or other damage)
- Prolonged seizures or numerous seizures without complete recovery between them (status epilepticus)
- Side effects of medications
Calling your health care provider:
Call your local emergency number (such as 911) if this is the first time a person has had a seizure or if a seizure is occurring in someone without a medical ID bracelet (which has instructions explaining what to do).
In the case of someone who has had seizures before, call 911 for any of these emergency situations:
- This is a longer seizure than the person normally has, or an unusual number of seizures for the person
- Repeated seizures over a few minutes
- Repeated seizures where consciousness or normal behavior is not regained between them (status epilepticus)
Call your health care provider if any new symptoms occur, including possible side effects of medications (drowsiness, restlessness, confusion, sedation, or others), nausea/vomiting, rash, loss of hair, tremors or abnormal movements, or problems with coordination.
Generally, there is no known way to prevent epilepsy. However, proper diet and sleep, and staying away from illegal drugs and alcohol, may decrease the likelihood of triggering seizures in people with epilepsy.
Reduce the risk of head injury by wearing helmets during risky activities; this can help lessen the chance of developing epilepsy.
Persons 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. If you have uncontrolled seizures, you should also avoid activities where loss of awareness would cause great danger, such as climbing to high places, biking, and swimming alone.
Foldvary-Schaefer N, Wyllie E. Epilepsy. In: Goetz CG, ed. Textbook of Clinical Neurology. 3rd ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 52.
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):1996-2007.
Spencer SS. Seizures and epilepsy. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 426.
Tomson T, Hiilesmaa V. Epilepsy in pregnancy. BMJ. 2007;335(7623):769-773.