Seizure (cont.)

Can Epilepsy be Prevented?

Many cases of epilepsy can be prevented by wearing seatbelts and bicycle helmets, putting children in car seats, and other measures that prevent head injury and other trauma. Prescribing medication after first or second seizures or febrile seizures also may help prevent epilepsy in some cases. Good prenatal care, including treatment of high blood pressure and infections during pregnancy, can prevent brain damage in the developing baby that may lead to epilepsy and other neurological problems later. Treating cardiovascular disease, high blood pressure, infections, and other disorders that can affect the brain during adulthood and aging also may prevent many cases of epilepsy. Finally, identifying the genes for many neurological disorders can provide opportunities for genetic screening and prenatal diagnosis that may ultimately prevent many cases of epilepsy.

How Can Epilepsy be Treated?

Accurate diagnosis of the type of epilepsy a person has is crucial for finding an effective treatment. There are many different ways to treat epilepsy. Currently available treatments can control seizures at least some of the time in about 80 percent of people with epilepsy. However, another 20 percent -- about 600,000 people with epilepsy in the United States -- have intractable seizures, and another 400,000 feel they get inadequate relief from available treatments. These statistics make it clear that improved treatments are desperately needed.

Doctors who treat epilepsy come from many different fields of medicine. They include neurologists, pediatricians, pediatric neurologists, internists, and family physicians, as well as neurosurgeons and doctors called epileptologists who specialize in treating epilepsy. People who need specialized or intensive care for epilepsy may be treated at large medical centers and neurology clinics at hospitals or by neurologists in private practice. Many epilepsy treatment centers are associated with university hospitals that perform research in addition to providing medical care.

Once epilepsy is diagnosed, it is important to begin treatment as soon as possible. Research suggests that medication and other treatments may be less successful in treating epilepsy once seizures and their consequences become established.

Medications

By far the most common approach to treating epilepsy is to prescribe antiepileptic drugs. The first effective antiepileptic drugs were bromides, introduced by an English physician named Sir Charles Locock in 1857. He noticed that bromides had a sedative effect and seemed to reduce seizures in some patients. More than 20 different antiepileptic drugs are now on the market, all with different benefits and side effects. The choice of which drug to prescribe, and at what dosage, depends on many different factors, including the type of seizures a person has, the person's lifestyle and age, how frequently the seizures occur, and, for a woman, the likelihood that she will become pregnant. People with epilepsy should follow their doctor's advice and share any concerns they may have regarding their medication.

Doctors seeing a patient with newly developed epilepsy often prescribe carbamazepine, valproate, lamotrigine, oxcarbazepine, or phenytoin first, unless the epilepsy is a type that is known to require a different kind of treatment. For absence seizures, ethosuximide is often the primary treatment. Other commonly prescribed drugs include clonazepam, phenobarbital, and primidone. Some relatively new epilepsy drugs include tiagabine, gabapentin, topiramate, levetiracetam, and felbamate. Other drugs are used in combination with one of the standard drugs or for intractable seizures that do not respond to other medications. A few drugs, such as fosphenytoin, are approved for use only in hospital settings to treat specific problems such as status epilepticus (see section, "Are There Special Risks Associated With Epilepsy?"). For people with stereotyped recurrent severe seizures that can be easily recognized by the person's family, the drug diazepam is now available as a gel that can be administered rectally by a family member. This method of drug delivery may be able to stop prolonged or repeated seizures before they develop into status epilepticus.

For most people with epilepsy, seizures can be controlled with just one drug at the optimal dosage. Combining medications usually amplifies side effects such as fatigue and decreased appetite, so doctors usually prescribe monotherapy, or the use of just one drug, whenever possible. Combinations of drugs are sometimes prescribed if monotherapy fails to effectively control a patient's seizures.

The number of times a person needs to take medication each day is usually determined by the drug's half-life, or the time it takes for half the drug dose to be metabolized or broken down into other substances in the body. Some drugs, such as phenytoin and phenobarbital, only need to be taken once a day, while others such as valproate must be taken two or three times a day.

Most side effects of antiepileptic drugs are relatively minor, such as fatigue, dizziness, or weight gain. However, severe and life-threatening side effects such as allergic reactions can occur. Epilepsy medication also may predispose people to developing depression or psychoses. People with epilepsy should consult a doctor immediately if they develop any kind of rash while on medication, or if they find themselves depressed or otherwise unable to think in a rational manner. Other danger signs that should be discussed with a doctor immediately are extreme fatigue, staggering or other movement problems, and slurring of words. People with epilepsy should be aware that their epilepsy medication can interact with many other drugs in potentially harmful ways. For this reason, people with epilepsy should always tell doctors who treat them which medications they are taking. Women also should know that some antiepileptic drugs can interfere with the effectiveness of oral contraceptives, and they should discuss this possibility with their doctors.

Since people can become more sensitive to medications as they age, they may need to have their blood levels of medication checked occasionally to see if the dose needs to be adjusted. The effects of a particular medication also sometimes wear off over time, leading to an increase in seizures if the dose is not adjusted. People should know that some citrus fruit, in particular grapefruit juice, may interfere with breakdown of many drugs. This can cause too much of the drug to build up in their bodies, often worsening the side effects.

People taking epilepsy medication should be sure to check with their doctor and/or seek a second medical opinion if their medication does not appear to be working or if it causes unexpected side effects.

Tailoring the dosage of antiepileptic drugs

When a person starts a new epilepsy drug, it is important to tailor the dosage to achieve the best results. People's bodies react to medications in very different and sometimes unpredictable ways, so it may take some time to find the right drug at the right dose to provide optimal control of seizures while minimizing side effects. A drug that has no effect or very bad side effects at one dose may work very well at another dose. Doctors will usually prescribe a low dose of the new drug initially and monitor blood levels of the drug to determine when the best possible dose has been reached.

Generic versions are available for many antiepileptic drugs. The chemicals in generic drugs are exactly the same as in the brand-name drugs, but they may be absorbed or processed differently in the body because of the way they are prepared. Therefore, patients should always check with their doctors before switching to a generic version of their medication.

Discontinuing medication

Some doctors will advise people with epilepsy to discontinue their antiepileptic drugs after 2 years have passed without a seizure. Others feel it is better to wait for 4 to 5 years. Discontinuing medication should always be done with a doctor's advice and supervision. It is very important to continue taking epilepsy medication for as long as the doctor prescribes it. People also should ask the doctor or pharmacist ahead of time what they should do if they miss a dose. Discontinuing medication without a doctor's advice is one of the major reasons people who have been seizure-free begin having new seizures. Seizures that result from suddenly stopping medication can be very serious and can lead to status epilepticus. Furthermore, there is some evidence that uncontrolled seizures trigger changes in neurons that can make it more difficult to treat the seizures in the future.

The chance that a person will eventually be able to discontinue medication varies depending on the person's age and his or her type of epilepsy. More than half of children who go into remission with medication can eventually stop their medication without having new seizures. One study showed that 68 percent of adults who had been seizure-free for 2 years before stopping medication were able to do so without having more seizures and 75 percent could successfully discontinue medication if they had been seizure-free for 3 years. However, the odds of successfully stopping medication are not as good for people with a family history of epilepsy, those who need multiple medications, those with focal seizures, and those who continue to have abnormal EEG results while on medication.

Surgery

When seizures cannot be adequately controlled by medications, doctors may recommend that the person be evaluated for surgery. Surgery for epilepsy is performed by teams of doctors at medical centers. To decide if a person may benefit from surgery, doctors consider the type or types of seizures he or she has. They also take into account the brain region involved and how important that region is for everyday behavior. Surgeons usually avoid operating in areas of the brain that are necessary for speech, language, hearing, or other important abilities. Doctors may perform tests such as a Wada test (administration of the drug amobarbital into the carotid artery) to find areas of the brain that control speech and memory. They often monitor the patient intensively prior to surgery in order to pinpoint the exact location in the brain where seizures begin. They also may use implanted electrodes to record brain activity from the surface of the brain. This yields better information than an external EEG.

A 1990 National Institutes of Health consensus conference on surgery for epilepsy concluded that there are three broad categories of epilepsy that can be treated successfully with surgery. These include focal seizures, seizures that begin as focal seizures before spreading to the rest of the brain, and unilateral multifocal epilepsy with infantile hemiplegia (such as Rasmussen's encephalitis). Doctors generally recommend surgery only after patients have tried two or three different medications without success, or if there is an identifiable brain lesion--a damaged or dysfunctional area--believed to cause the seizures.

A study published in 2000 compared surgery to an additional year of treatment with antiepileptic drugs in people with longstanding temporal lobe epilepsy. The results showed that 64 percent of patients receiving surgery became seizure-free, compared to 8 percent of those who continued with medication only. Because of this study and other evidence, the American Academy of Neurology (AAN) now recommends surgery for TLE when antiepileptic drugs are not effective. However, the study and the AAN guidelines do not provide guidance on how long seizures should occur, how severe they should be, or how many drugs should be tried before surgery is considered. A nationwide study is now underway to determine how soon surgery for TLE should be performed.

If a person is considered a good candidate for surgery and has seizures that cannot be controlled with available medication, experts generally agree that surgery should be performed as early as possible. It can be difficult for a person who has had years of seizures to fully re-adapt to a seizure-free life if the surgery is successful. The person may never have had an opportunity to develop independence, and he or she may have had difficulties with school and work that could have been avoided with earlier treatment. Surgery should always be performed with support from rehabilitation specialists and counselors who can help the person deal with the many psychological, social, and employment issues he or she may face.

While surgery can significantly reduce or even halt seizures for some people, it is important to remember that any kind of surgery carries some amount of risk (usually small). Surgery for epilepsy does not always successfully reduce seizures and it can result in cognitive or personality changes, even in people who are excellent candidates for surgery. Patients should ask their surgeon about his or her experience, success rates, and complication rates with the procedure they are considering.

Even when surgery completely ends a person's seizures, it is important to continue taking seizure medication for some time to give the brain time to re-adapt. Doctors generally recommend medication for 2 years after a successful operation to avoid new seizures.

Surgery to treat underlying conditions

In cases where seizures are caused by a brain tumor, hydrocephalus, or other conditions that can be treated with surgery, doctors may operate to treat these underlying conditions. In many cases, once the underlying condition is successfully treated, a person's seizures will disappear as well.

Surgery to remove a seizure focus

The most common type of surgery for epilepsy is removal of a seizure focus, or small area of the brain where seizures originate. This type of surgery, which doctors may refer to as a lobectomy or lesionectomy, is appropriate only for focal seizures that originate in just one area of the brain. In general, people have a better chance of becoming seizure-free after surgery if they have a small, well-defined seizure focus. Lobectomies have a 55-70 percent success rate when the type of epilepsy and the seizure focus is well-defined. The most common type of lobectomy is a temporal lobe resection, which is performed for people with temporal lobe epilepsy. Temporal lobe resection leads to a significant reduction or complete cessation of seizures about 70 - 90 percent of the time.

Multiple subpial transection

When seizures originate in part of the brain that cannot be removed, surgeons may perform a procedure called a multiple subpial transection. In this type of operation, which has been commonly performed since 1989, surgeons make a series of cuts that are designed to prevent seizures from spreading into other parts of the brain while leaving the person's normal abilities intact. About 70 percent of patients who undergo a multiple subpial transection have satisfactory improvement in seizure control.

Corpus callosotomy

Corpus callosotomy, or severing the network of neural connections between the right and left halves, or hemispheres, of the brain, is done primarily in children with severe seizures that start in one half of the brain and spread to the other side. Corpus callosotomy can end drop attacks and other generalized seizures. However, the procedure does not stop seizures in the side of the brain where they originate, and these focal seizures may even increase after surgery.

Hemispherectomy and hemispherotomy

These procedures remove half of the brain's cortex, or outer layer. They are used predominantly in children who have seizures that do not respond to medication because of damage that involves only half the brain, as occurs with conditions such as Rasmussen's encephalitis, Sturge-Weber syndrome, and hemimegencephaly. While this type of surgery is very radical and is performed only as a last resort, children often recover very well from the procedure, and their seizures usually cease altogether. With intense rehabilitation, they often recover nearly normal abilities. Since the chance of a full recovery is best in young children, hemispherectomy should be performed as early in a child's life as possible. It is rarely performed in children older than 13.

Devices

The vagus nerve stimulator was approved by the U.S. Food and Drug Administration (FDA) in 1997 for use in people with seizures that are not well-controlled by medication. The vagus nerve stimulator is a battery-powered device that is surgically implanted under the skin of the chest, much like a pacemaker, and is attached to the vagus nerve in the lower neck. This device delivers short bursts of electrical energy to the brain via the vagus nerve. On average, this stimulation reduces seizures by about 20 - 40 percent. Patients usually cannot stop taking epilepsy medication because of the stimulator, but they often experience fewer seizures and they may be able to reduce the dose of their medication. Side effects of the vagus nerve stimulator are generally mild but may include hoarseness, ear pain, a sore throat, or nausea. Adjusting the amount of stimulation can usually eliminate most side effects, although the hoarseness typically persists. The batteries in the vagus nerve stimulator need to be replaced about once every 5 years; this requires a minor operation that can usually be performed as an outpatient procedure.

Several new devices may become available for epilepsy in the future. Researchers are studying whether transcranial magnetic stimulation (TMS), a procedure which uses a strong magnet held outside the head to influence brain activity, may reduce seizures. They also hope to develop implantable devices that can deliver drugs to specific parts of the brain.

Diet

Studies have shown that, in some cases, children may experience fewer seizures if they maintain a strict diet rich in fats and low in carbohydrates. This unusual diet, called the ketogenic diet, causes the body to break down fats instead of carbohydrates to survive. This condition is called ketosis. One study of 150 children whose seizures were poorly controlled by medication found that about one-fourth of the children had a 90 percent or better decrease in seizures with the ketogenic diet, and another half of the group had a 50 percent or better decrease in their seizures. Moreover, some children can discontinue the ketogenic diet after several years and remain seizure-free. The ketogenic diet is not easy to maintain, as it requires strict adherence to an unusual and limited range of foods. Possible side effects include retarded growth due to nutritional deficiency and a buildup of uric acid in the blood, which can lead to kidney stones. People who try the ketogenic diet should seek the guidance of a dietician to ensure that it does not lead to serious nutritional deficiency.

Researchers are not sure how ketosis inhibits seizures. One study showed that a byproduct of ketosis called beta-hydroxybutyrate (BHB) inhibits seizures in animals. If BHB also works in humans, researchers may eventually be able to develop drugs that mimic the seizure-inhibiting effects of the ketogenic diet.

Other Treatment Strategies

Researchers are studying whether biofeedback -- a strategy in which individuals learn to control their own brain waves -- may be useful in controlling seizures. However, this type of therapy is controversial and most studies have shown discouraging results. Taking large doses of vitamins generally does not help a person's seizures and may even be harmful in some cases. But a good diet and some vitamin supplements, particularly folic acid, may help reduce some birth defects and medication-related nutritional deficiencies. Use of non-vitamin supplements such as melatonin is controversial and can be risky. One study showed that melatonin may reduce seizures in some children, while another found that the risk of seizures increased measurably with melatonin. Most non-vitamin supplements such as those found in health food stores are not regulated by the FDA, so their true effects and their interactions with other drugs are largely unknown.

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