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Brain Image Gallery Epilepsy has been compared to an electrical storm in the brain. See more brain pictures.

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Epilepsy Overview

Imagine yourself behind the wheel, coming up on a four-way stop. You have places you'd really like to be, so you're impatient with the rules of the road, which dictate a certain order by which drivers advance through the intersection. Yet you know that if you were to barrel through the stop sign, you'd likely cause an accident with those drivers that had the right-of-way. Cars would pile up, horns would honk and your neck might feel out of whack. Your feelings would rapidly change as you consider everything from your soon-to-rise insurance premiums to concerns for occupants of the other cars.

­The brain operates in much the same way. Most of the time, neurons release ordered electrical pulses which dart around the brain delivering messages to the spinal cord, muscles and nerves. But when all the neurons start firing at once, the brain can be subject to traffic jams as well. The neurons' rapid and wild firing overwhelms the rest of the brain, causing a seizure to occur. Epilepsy is a neurological disorder characterized by recurring seizures. It's estimated that about 50 million people worldwide suffer from epilepsy, but it's still a fairly misunderstood and stigmatized condition [source: Baruchin].

In ancient days, seizures were alternately believed to be communication with the divine or with the devil. A seizure was proof-positive that you were dealing with a witch during the 15th century. Some may picture actress Natalie Portman wearing a helmet in the 2004 film "Garden State" when they think of epilepsy. The title of the 1997 book "The Spirit Catches You and You Fall Down" refers to how a family from Laos described their daughter's seizures. Others call seizures electrical storms in the brain.

But what causes these electrical storms, these traffic jams? And how does a person deal with epilepsy? We'll investigate these questions, starting with how a seizure works. Most of the time, the neurons in your brain are firing at a rate of 80 times per second; during a seizure, the neurons fire at 500 times per second [source: Judd]. Obviously something's going on in the brain, but how does that manifest itself in the body? Turn the page to find out.

 

Pedro Ugarte/AFP/Getty Images Rescue personnel assist a woman who had an epileptic attack after a suicide bombing in Tel Aviv.

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Epileptic Seizures

We may have some ideas of what a seizure looks like -- convulsions, twitching, drooling. But not all seizures are the same. Doctors classify seizures into two broad groups: focal seizures (sometimes called partial seizures) and generalized seizures. Focal seizures occur in just one area of the brain; these types of seizures are experienced by about 60 percent of people with epilepsy [source: NINDS]. Generalized seizures occur in both sides of the brain.

But within those two groups, there's still a wide range of seizure types, which in turn create an immense range of sensations. Focal seizures are further broken down as either simple or complex. When a person suffers a simple focal seizure, he or she maintains consciousness, but experiences abnormal feelings or sensations. The person might sense things that aren't there. Sometimes a simple focal seizure is an aura, or an indication that a complex focal seizure is about to come. A complex focal seizure does involve a loss of consciousness, so that the person enters a dreamlike state. To an observer, a person experiencing a complex focal seizure may engage in repetitive behaviors including twitching, blinking or walking in a circle.

There are many more types of generalized seizures. These seizures include:

  • Absence seizures generally occur in children. As the name implies, the person briefly goes absent from the conscious world. It's like the child is staring into space, though eyelids may flutter and muscles may twitch. These seizures last for just a few seconds, and then the child resumes activity almost as quickly as before.
  • Clonic seizures cause convulsions, or jerking movements on both sides of the body.
  • Myoclonic seizures involve jerking of the upper body and the limbs. It may look like the person has been shocked.
  • Tonic seizures result in sudden stiffness in the muscles. These seizures are more common in sleep.
  • Atonic seizures involve a loss of muscle control, causing the person to droop or fall. Although these seizures may be quick, they can cause sudden falls, resulting in further injury.
  • Tonic-clonic seizures involve a combination of both tonic and clonic seizure symptoms. The person quickly stiffens, loses consciousness and then convulses with repeated jerking of the arms and legs.

You may have heard the phrases "grand mal" and "petit mal" used to describe a seizure. These terms are considered outdated and inaccurate, so you shouldn't hear a doctor using them. Tonic-clonic seizure is the more appropriate term for a grand mal seizure, while absence seizures describe the seizures formally known as petit mal.

Most seizures are generally brief, lasting either just a few seconds or at most a few minutes. The period after a seizure is known as the postictal state; it may include a headache, soreness, confusion and fatigue. If a seizure lasts longer than five minutes, the person is entering a state known as status epilectus and requires medical attention.

Not all seizures, however, require immediate medical attention. If someone near you has a seizure, you shouldn't leave them to call 911. The most important thing to do is remain calm and take actions that will prevent the person from harming himself or herself. Roll the person on his or her side to prevent choking, but don't try to put anything in the mouth, like a spoon. Many onlookers try to do this, thinking it will prevent a seizure sufferer from swallowing his or her own tongue, but this won't happen. Cushioning the person's head, loosening tight clothing and removing nearby objects are all actions that will prevent the person from causing personal injury or harm, but if the person wants to wander around, allow him or her to do so. Stay with the person until the seizure ends and be patient as he or she recovers from the seizure. Then you can make the determination of who to call. It may be 911 if the person is pregnant, the seizure lasts for more than five minutes or the person becomes injured during the seizure.

So how do these individual seizures relate to a diagnosis of epilepsy? Turn the page to find out.

Frontal lobe epilepsy and temporal lobe epilepsy affect the parts of the brain indicated in the illustration.

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Temporal Lobe Epilepsy, Benign Rolandic Epilepsy and Other Types of Epilepsy

Just as there is more than one type of seizure, there's more than one type of epilepsy. Doctors determine which kind a person has by looking at the patient's age and the types of seizures suffered, as well as diagnostic tests (which we'll talk about in the next section). But first, let's review some of the most common forms of epilepsy.

  • Benign rolandic epilepsy is a form of childhood epilepsy that is usually outgrown by adolescence. This condition is marked by nighttime seizures that involve twitching, numbness or tingling, but sometimes, larger tonic-clonic seizures may occur as well.
  • While juvenile myoclonic epilepsy may manifest itself near the time of puberty, it's usually a lifelong condition -- unlike benign rolandic epilepsy. As the name implies, myoclonic seizures define this condition, though tonic-clonic or absence seizures are also possible.
  • Lennox-Gastaut syndrome is a severe form of epilepsy that involves several types of seizures as well as mental disability. Unlike some other childhood epilepsies, this one is typically present for life.
  • Reflex epilepsy occurs when seizures are triggered by specific environmental triggers. These may include flashing lights, startling noises, certain music, certain movements, or being touched on certain parts of the body.
  • In temporal lobe epilepsy, complex focal seizures are the most common seizure type, though simple focal seizures and tonic-clonic seizures are also common. Seizures that occur as part of temporal lobe epilepsy are frequently described by just how hard they are to describe. The temporal lobe controls emotion and memory, so seizures often distort these two things. People with temporal lobe epilepsy describe foreign emotions, a deluge of old memories flooding back or hallucinations.
  • Frontal lobe epilepsy involves disturbances in motor and behavioral centers in the brain. People with this type of epilepsy are more likely to have jerking or stiffness on one side of the body.

E­pilepsy can begin at any age, but it's most common in young children and the elderly. About half of all epilepsy patients are children [source: Baruchin]. The disorder is common in older people because of other neurological conditions such as stroke or dementia. People older than age 75 are at the greatest risk of developing epilepsy [source: Wilner].

So what causes epilepsy? In some cases, it's a brain injury, such as a tumor, a stroke or a blow to the head. When doctors can determine this cause, it's considered symptomatic epilepsy. In some instances, epilepsy is inherited, and certain genes are to blame; so far, scientists have found more than 200 gene abnormalities associated with epilepsy [source: Wilner]. But in a large number of cases, doctors simply don't know why the patient begins suffering seizures. When doctors don't know what causes the seizures, the patient has idiopathic epilepsy. Cryptogenic epilepsy is the term for cases in which doctors don't have enough information to decide if the case is symptomatic or idiopathic; in this instance, doctors may have a hunch that can't be substantiated.

While there may be many unknowns in what causes epilepsy, doctors do have a wide range of tools to aid in the diagnosis of epilepsy. Read on to find out what they are.

A patient prepares for an EEG.

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Diagnosing Epilepsy

When you have one seizure, you don't necessarily have epilepsy or a seizure disorder. But you should head for the doctor's office, because testing may be able to determine the likelihood of a second episode by revealing abnormalities in the brain. Once you have one seizure, the chances have increased that you'll have another. Because people who suffer epileptic seizures may not know what's happening while they're occurring, it's usually helpful for the doctor if a witness to the seizure is present.

To diagnose epilepsy, doctors consider the types of seizures and the medical history of the patient. There are also blood tests to determine any underlying causes. But the most useful tools in diagnosing epilepsy are the tests that allow doctors to peek inside the brain.

The primary test is an electroencephalograph, or EEG, which allows the doctors to check for abnormal brain wave activity. To perform this test, doctors place electrodes at various points on the head and monitor the brain waves. If you've ever seen a television crime show with a lie detector, you know that the lie detector jerks violently when the person tells a lie. Similarly, a person's brain waves during a seizure are far more jagged, with higher peaks and valleys, than normal brain waves. Doctors may try to provoke a seizure during the exam; some methods include using flashing lights or asking the patient to come in on very little sleep. Both exhaustion and flashing lights are common seizure triggers.

Doctors may follow up an EEG with a brain scan, using an imaging device such as an MRI or a CT. This allows the doctor to see where any abnormalities in the brain may be; a lesion on the frontal lobe, for example, indicates frontal lobe epilepsy.

Doctors are using these tests to distinguish between other conditions that mimic epilepsy. Some of the conditions that include seizures which may resemble epileptic seizures include fainting, hypoglycemia, sleep apnea, an abnormal heart rhythm and panic attacks. Additionally, when an alcoholic or drug addict stops consuming those substances, the stress in the body could generate a seizure. Many infants and small children experience febrile seizures when they have a high fever, but they may not go on to have epilepsy.

One seizure that commonly leads to the misdiagnosis of epilepsy is a pseudoseizure. These incidents have the outward appearance of seizures, but the brain activity isn't the same as in people with epilepsy. These are more likely have an underlying psychological cause, like sexual abuse [sources: Wilner, Khamsi]. If patients suffering non-epileptic seizures take the drugs prescribed for epilepsy, they could damage their body. Pregnant women, for example, may be at a higher risk of delivering a baby with birth defects due to the medication [source: Khamsi].

Once doctors determine epilepsy, is there anything that can be done? As early as 400 B.C., Hippocrates was writing about epilepsy as a disease of the brain that should be treated with diet and drugs. However, in the interim years, people with epilepsy suffered through a host of more superstitious cures, including drinking a gladiator's blood or killing a dog and drinking its bile. Witnesses to a seizure were advised to urinate into a shoe and provide it as a beverage to the person having the seizure [source: Wilner].

Let's not focus on these primitive cures, which also included eating a pigeon. Rather, let's focus on the treatments used today. Go to the next page to find out if Hippocrates had it right.

This illustration from 1250 shows Saint Valentine curing an epileptic.

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Epilepsy Treatment

Prescription medication is commonly used to control epileptic seizures. Since seizures come in all shapes and sizes, one pill doesn't magically serve them all. Doctors and patients often engage in a tricky tango of finding just the right medication and dosage that will control seizures without causing debilitating side effects. Patients may have to try many drugs to find that winning combination of seizure control and quality of life, as many of the medications are considered disabling because they affect memory, thought and other cognitive processes.

If seizures are isolated in one part of the brain, then patients are candidates for a surgery to remove that part of the brain. For example, in an anterior temporal lobectomy, the most common epilepsy surgery, the front part of the temporal lobe is removed. Doctors can also remove parts of other lobes, or they can disconnect parts of the brain that aren't communicating properly. One such surgery is a corpus callosotomy, which cuts away the white matter connecting the hemispheres of the brain. These surgeries can be performed on both adults and children. While descriptions of removing parts of the brain may call to mind horrifying accounts of lobotomies, these surgeries remove the damaged part of the brain only, and they don't seem to result in either new seizure centers or in brain damage. Some patients show intellectual improvements after the surgery [source: Wilner].

A ketogenic diet is sometimes recommended for children with epilepsy, though it does not appear to be as effective in controlling seizures in adults. This diet is very similar to the Atkins Diet, in that no carbohydrates whatsoever are allowed. The diet is very high in fat and can be difficult to maintain. Scientists aren't sure exactly how the diet works; the seizure control may be due to a protein that occurs when the body breaks down fat.

In 1997, the FDA approved a device called the vagus nerve stimulator for people with epilepsy. The implanted device sends regular waves of electricity to the brain, much as a cardiac pacemaker creates rhythmic pulses to aid the heart. Since vagus nerve stimulation does not usually result in full seizure control, some medication may be necessary, but the lowered dosage cuts down on the wearying side effects [source: Wilner].

Some people may be able to practice a form of self-control over their seizures as they get better at predicting when an episode may occur. Some common seizure triggers include sleep deprivation, alcohol or drug use, stress, illness, the menstrual cycle and diet. When people recognize their most common seizure triggers, they may be able to block a seizure by getting more sleep, focusing on something else, moving around or even just repeating "no" to themselves [source: Devinsky].

About 25 to 30 percent of people with epilepsy continue to experience seizures even with treatment, a condition known as intractable epilepsy [source: NINDS]. Others, especially children, are able to "outgrow" epilepsy and reduce their medication levels. It's important to note that it's possible to die from epilepsy, though doctors aren't sure why, as you'll glean from the name: sudden unexplained death in epilepsy, or SUDEP.

Even when controlled, though, epilepsy can have an effect on daily life, largely due to its unpredictability. The disorder can affect all decisions, from whether to go for a swim to where you work. In the United States, each state has different rules about epileptic drivers; in some cases, a person must be seizure-free for six to 12 months before getting behind the wheel. People with epilepsy often feel a sense of social isolation, as they lack control over their brain and body and worry what others will think of their seizures.

Women with epilepsy face special challenges. Some epilepsy medications carry the risk of birth defects, but so do uncontrolled seizures while the baby is in the womb. After the baby is born, a woman may worry about her ability to care for an infant with the unpredictability of seizures; women should consult with both their neurologist and obstetrician to chart a plan of action.

To learn more about epilepsy, see the stories on the next page.

Lots More Information

Related HowStuffWorks ArticlesMore Great LinksSources
  • Baruchin, Aliyah. "Easing the Seizures, and Stigma, of Epilepsy." New York Times. Feb. 20, 2007. (Aug. 18, 2008) http://health.nytimes.com/ref/health/healthguide/esn-epilepsy-ess.html
  • Beers, Mark H., ed. "The Merck Manual of Medical Information. Second Home Edition." Merck Research Laboratories. 2003.
  • Devinsky, Orrin. "Epilepsy Patient & Family Guide. Third Edition." Demos Medical Publishing. 2008.
  • Judd, Sandra J., ed. "Brain Disorders Sourcebook, Second Edition." Health Reference Series. Omnigraphics. 2005.
  • Khamsi, Roxanne. "One in five epilepsy diagnoses may be wrong." New Scientist. June 13, 2006. (Aug. 18, 2008) http://www.newscientist.com/channel/health/dn9325-one-in-five-epilepsy-diagnoses-may-be-wrong.html
  • National Institute of Neurological Disorders and Stroke "Curing Epilepsy: The Promise of Research." Oct. 26, 2007. (Aug. 18, 2008) http://www.ninds.nih.gov/disorders/epilepsy/epilepsy_research.htm
  • Wilner, Andrew N. "Epilepsy 199 Questions: A Doctor Responds to His Patients' Questions. Third Edition." Demos Medical Publishing. 2008.