Epilepsy
Centers for Disease Control and Prevention

What is epilepsy?

Epilepsy, sometimes referred to as seizure disorder, is a general term that refers to a tendency to have recurrent seizures.A seizure is a temporary disturbance in brain function in which groups of nerve cells in the brain signal abnormally and excessively.Nerve cells or neurons normally produce electrical impulses that act on other nerve cells, muscles, or glands to create awareness, thought, sensations, actions, and control of internal body functions.During a seizure, disturbances of nerve cell activity produce symptoms that vary depending on which part (and how much) of the brain is affected. Seizures may produce changes in awareness or sensation, involuntary movements, or other changes in behavior.Usually, a seizure lasts from a few seconds to a few minutes.

What are seizures?

There are many types of seizures. These can be classified into two broad groups:

Primary generalized seizures—seizures begin with widespread involvement of both sides of the brain. Partial seizures—seizures begin with involvement of a smaller, localized area of the brain. With some partial seizures, the disturbance can still spread within seconds or minutes to involve widespread areas of the brain (secondary generalized seizure).

Some people have seizures that are hardly noticeable to others. Sometimes, the only clue that a person is having an absence seizure—a type of primary generalized seizure sometimes called petit mal—is rapid blinking or a few seconds of staring into space. In contrast, a person having a complex partial seizure may appear confused or dazed and will not be able to respond to questions or direction for up to a few minutes. Finally, a person having a generalized tonic-clonic seizure, sometimes called grand mal, may cry out, lose consciousness, fall to the ground, and have rigidity and muscle jerks lasting up to a few minutes, with an extended period of confusion and fatigue afterward.

A more detailed explanation of the diagnosis of seizure types and epilepsy syndromes may be found in a publication of the National Institute of Neurological Disorders and Stroke, Seizures and Epilepsy: Hope Through Research.

Is having a seizure the same as having epilepsy?

Not necessarily.In general, seizures do not indicate epilepsy if they only occur as a result of a temporary medical condition such as a high fever, low blood sugar, alcohol or drug withdrawal, or immediately following a brain concussion.Among people who experience a seizure under such circumstances, without a history of seizures at other times, there is usually no need for ongoing treatment for epilepsy, only a need to treat the underlying medical condition.

What is the burden of epilepsy in the United States?

Based on recent surveys, CDC estimates that nearly 2.5 million people in the United States have epilepsy. A more conservative estimate suggests that about 2.1 million people currently have epilepsy, with 150,000 developing the condition each year. [Reference] New cases of epilepsy are most common among children and older adults.

The total indirect and direct cost of epilepsy in the United States is estimated to be $15.5 billion. This estimate is based on a reported cost of $12.5 billion in 1995 [Reference] convertedto 2004 dollar value using Bureau of Labor Statistics data.

What causes epilepsy?

Epilepsy may arise when there are disruptions to the normal connections between nerve cells in the brain(much like disruptions in wiring of a complex electrical circuit), when there are imbalances of natural chemicals or neurotransmitters that are important to the signaling among nerve cells, or when there are changes in the membranes of nerve cells, including proteins called ion channels, that alter their normal sensitivity. Some of these disruptions, imbalances, and changes may develop early in life, sometimes related to hereditary factors and sometimes related to early exposures and events.Others may be acquired later.Among known conditions and events that may lead to epilepsy are:

Oxygen deprivation (e.g., during childbirth). Brain infections (e.g., meningitis, encephalitis, cysticercosis, or brain abscess). Traumatic brain injury or head injury. Stroke (resulting from a block or rupture of a blood vessel in the brain). Other neurologic diseases (e.g., Alzheimer disease). Brain tumors. Certain genetic disorders.

In nearly two-thirds of the cases of epilepsy, a specific underlying cause is not identified. In these instances, the cause may be labeled cryptogenic if the cause is unknown, or idiopathic if the epilepsy is not associated with other neurologic disease but is consistent with certain syndromes that may be inherited.

A more detailed explanation of the causes of epilepsy may be found in a publication of the National Institute of Neurological Disorders and Stroke, Seizures and Epilepsy: Hope Through Research

Can epilepsy be prevented?

Sometimes epilepsy may be preventable. Considering the causes of epilepsy listed above, there are several opportunities for prevention. Some of the most important are:

Complications of pregnancy and childbirth. Proper prenatal care to avoid problems during pregnancy and childbirth may lessen complications that could lead to epilepsy. For CDC’s information on a healthy pregnancy, see http://www.cdc.gov/ncbddd/bd/abc.htm Infections. Proper immunization (vaccination) against certain diseases of childhood and adolescence or young adulthood may lessen the likelihood of infections that can sometimes involve the central nervous system and lead to epilepsy. CDC recommendations for vaccines and immunizations are found at http://www.cdc.gov/vaccines/. A parasitic infection called cysticercosis is a common cause of epilepsy in some developing countries and some U.S. immigrant populations. Cysticercosis can be prevented through public health screening and early treatment as well as proper practices of hygiene and food preparation. Traumatic brain injuries. Brain injuries, often due to motor vehicle crashes or falls, are a frequent cause of epilepsy. There are effective ways to reduce the occurrence and severity of motor vehicle and traffic injuries: consistently using safety belts (and safety seats for small children), airbags, bicycle helmets, and motorcycle helmets. While older adults have an increased risk of brain injuries due to falls, there are effective measures to reduce this risk as well. The risk of developing epilepsy is especially high with penetrating or severe brain injuries, which occur commonly in war. Responding to needs that have increased as a result of recent wars in Iraq and Afghanistan, the Defense and Veterans Brain Injury Program addresses the treatment of these injuries among military personnel and veterans.

More information on traumatic brain injuries and their prevention can be found at http://www.cdc.gov/ncipc/tbi/TBI.htm. More information on motor vehicle occupant safety pdf (PDF–1.4Mb) and motorcycle safety pdf (PDF–4.7Mb) can be obtained from the U.S. National Highway Traffic Safety Administration.

Stroke. Reducing or treating risk factors such as physical inactivity, high blood pressure, obesity, diabetes, high cholesterol, and smoking will lessen the likelihood of stroke and heart disease, which may help to reduce the possibility of developing epilepsy later in life. More information about preventing stroke and heart disease can be found at http://www.cdc.gov/nccdphp/publications/factsheets/Prevention/dhdsp.htm

How is epilepsy treated?

Before a person begins treatment, the first step is to ensure that the diagnosis of epilepsy is correct and to determine, if possible, the type of epilepsy and whether there are any underlying conditions that also need treatment. This will require a careful review of the person’s medical history and a neurological examination. Other tests may be recommended as well, usually including an electroencephalogram (EEG) and often a brain scan such as computed tomography (CT) or magnetic resonance imaging (MRI). The medical decision about how best to treat the epilepsy is based on this evaluation.

Antiepileptic drugs are the mainstay of treatment for most people. There are now many drugs available, and a doctor may recommend one or more of these based on several individual patient factors such as the type of epilepsy, the frequency and severity of the seizures, age, and related health conditions. After starting a medication, close monitoring is required for awhile to assess the effectiveness of the drug as well as possible side effects.Early in treatment, adjustments in dosage are often required. Sometimes, because of continued seizures or significant side effects, it is necessary to change to a different drug.For about two-thirds of people with epilepsy receiving optimum treatment, drugs are successful in fully controlling seizures.For the remainder, although drugs may have a partial benefit, some seizures continue to occur. For some of these people, other treatment options may be considered. Surgery. With certain types of partial epilepsy, especially when it can be determined that seizures consistently arise from a single area of the brain (the “seizure focus”), surgery to remove that focus may be effective in stopping future seizures or making them much easier to control with medication. Epilepsy surgery is most commonly performed when a seizure focus is located within the temporal lobe of the brain. Other options. Other supplemental treatments are sometimes beneficial when medications alone are inadequate and surgery is not possible. These include vagus nerve stimulation, where an electrical device is implanted to intermittently stimulate a large nerve in the neck, and the ketogenic diet, a high fat, low carbohydrate diet with restricted calories.

A more detailed explanation of the treatment options for epilepsy and their indications, benefits, and side effects may be found in a publication of the National Institute of Neurological Disorders and Stroke, Seizures and Epilepsy: Hope Through Research.

Who treats epilepsy?

Doctors from several medical specialties may be involved in the treatment of people with epilepsy. Primary care doctors such as family physicians, pediatricians, and internists are often the first doctors to see a patient with new seizures and they may make the initial diagnosis of epilepsy or they may consult with a neurologist—a specialist in the brain and nervous system—to confirm the diagnosis and recommend treatment.Often primary care doctors provide follow-up care for patients with epilepsy, but when problems arise such as medication side effects or recurring seizures, the patients may be referred to a neurologist or pediatric neurologist for consultation or continuing care.Some neurologists with advanced training further specialize in the diagnosis and treatment of epilepsy, a subspecialty called epileptology.People whose seizures are difficult to control or who need specialized or intensive care for epilepsy may be referred to epileptologists or to specialized epilepsy centers.Epilepsy centers have advanced diagnostic and treatment capabilities and are staffed by epileptologists and other physicians, psychologists, nurses, and technicians specializing in epilepsy care. Epilepsy center staff or consultants often also include neurosurgeons specializing in epilepsy surgery.Many epilepsy treatment centers are associated with university hospitals that perform research in addition to providing medical care.

How do I find an epilepsy specialist?

There are a number of resources that can provide guidance in seeking specialty care.Primary care doctors can usually provide a referral to neurologists in the area and may be able to identify those who subspecialize in epilepsy.The American Academy of Neurology provides a listing of its member neurologists and the American Epilepsy Society as well as the Epilepsy Foundation provide listings of epilepsy specialists. The National Association of Epilepsy Centers also provides a list of its member centers, organized by state

What issues are unique for women with epilepsy?

Women with epilepsy can experience difficulties arising from hormonal changes during their reproductive cycle that sometimes can affect the tendency to have seizures. Pregnancy brings some special considerations for women with epilepsy, because seizure occurrence and certain drugs taken during this time may sometimes carry a risk of harm to the developing fetus. Usually these risks can be minimized by several precautions women can take before and during pregnancy. The Epilepsy Foundation has a special initiative, Women and Epilepsy, that focuses on improving health outcomes in women with epilepsy.

Can epilepsy be fatal?

Most people with epilepsy live a full life span. Nevertheless, the risk of premature death is increased for some, depending on several factors:

Sometimes epilepsy is a symptom of a more serious underlying condition such as a stroke or a tumor that carries an increased risk of death. People with some types of epilepsy who continue to have major seizures can experience injuries during a seizure from falling or hurting their head that may occasionally be life-threatening. Very prolonged seizures or seizures in rapid succession, a condition called status epilepticus, can also be life-threatening. Status epilepticus can sometimes occur when seizure medication use is stopped suddenly. Rarely, people with epilepsy can experience sudden death (SUDEP). These events are not well understood, although they are suspected sometimes to be due to heart rhythm disturbances during a seizure.(Sudden death due to heart rhythm disturbances, of course, also occurs in the general population.) The risk of sudden death is not increased for all types of epilepsy, but occurs more among people with major seizures—especially generalized tonic-clonic seizures—that are not well controlled.

To a great extent, it appears that optimal seizure control and some common-sense safety measures can reduce the risk of epilepsy-related mortality.

Can people who have epilepsy drive?

Most states and the District of Columbia will not issue a driver’s license to someone with epilepsy unless it can be documented that he or she has gone a specific amount of time without a seizure. The seizure-free period ranges from a few months to over a year. Some states rely on a physician’s recommendation and may allow a license to be issued when a person has seizures that don’t impair consciousness, occur only during sleep, or have long auras or other warning signs that allow the person to avoid driving when a seizure is likely to occur. The Epilepsy Foundation provides state-specific information about driving laws at http://www.epilepsyfoundation.org/living/wellness/transportation/drivinglaws.cfm.