Epilepsy



Epilepsy (EP-i-lep-see) is a condition of the nervous system characterized by recurrent seizures that temporarily affect a person's awareness, movements, or sensations. Epileptic seizures occur when powerful, rapid bursts of electrical energy interrupt the normal electrical patterns of the brain. The cause of epilepsy is unknown in most cases, but it is known that some cases are hereditary, or run in families. Epilepsy is not contagious.

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Brain function

Neurology

Seizures

Erin's Story

It happened at her birthday party. Eleven-year-old Erin was ready to blow out the candles on her cake when she suddenly released a loud cry and dropped to the carpet. Her arms and legs thrashed and twitched. When her friends called to her she did not respond. Her mother knelt beside her, turned Erin gently onto her side, and loosened the top button on her shirt. In a few moments, Erin regained consciousness, exhausted and more than a little embarrassed that her friends had seen what had happened. She was not scared because it had occurred before. Her mother explained to her friends that Erin had had an epileptic seizure, and that as soon as she had time to rest, she would be fine.

What Is Epilepsy?

In a normal brain, millions of tiny electrical charges pass between nerve cells and to all parts of the body. Those cells "fire" in an orderly and controlled manner. In the brain of a person with epilepsy, overactive nerve cells send out powerful, rapid electrical charges that disrupt the brain's normal function. During a seizure such as the one experienced by Erin, brain cells can fire at up to four times their normal rate, temporarily affecting how a person behaves, moves, thinks, or feels.

Some people with epilepsy know what will trigger a seizure, but others do not. Many people with epilepsy can sense that they are about to have a seizure. The attack may be preceded by a feeling of unease, anxiety, or discomfort. They may sense or see flickering lights. Despite these warning signals, people with epilepsy still cannot stop the oncoming seizure.

What Causes Epilepsy?

Because epilepsy is not contagious, one person cannot catch epilepsy from another. In about 7 out of 10 cases, doctors describe the disease as idiopathic (id-ee-o-PATH-ik), which means the cause is unknown. Most people with idiopathic seizures are between ages 5 and 20 and have no brain injuries or abnormalities. Many do, however, have a family history of epilepsy or seizure disorders.

The U.S. and the World

  • Epilepsy is a common neurologic disease in the United States, affecting more than 6 out of every 1,000 people.
  • Epilepsy most frequently begins in early childhood, during adolescence, or after age 65.
  • Among people with epilepsy, 20 percent develop the disorder before age 5, and 50 percent develop it before age 25.
  • Worldwide, some form of epilepsy affects about 40 million people. About 32 million of those people have inadequate access to medical treatment.

The Road to Understanding

Ancient Greeks believed epileptic seizures were blessed visitations from the gods. During the Renaissance, a seizure was seen as a sign that a person was possessed by the devil.

In the early 1800s, epilepsy was still misunderstood. It was believed to be contagious, and people with the disease were often locked away in hospitals or "epileptics only" sanitariums.

By the mid-1800s, neurologists (doctors who treat disorders and diseases of the brain and spinal cord) began to investigate epilepsy and to make progress toward a better understanding of the disorder.

In other cases, the following have been identified as causes of epilepsy:

  • Maternal injury, infection, or illness that affects a developing fetus during pregnancy.
  • Brain injuries. Although brain injuries can occur at any age, the highest incidence is among young adults. These injuries often result from car collisions, sports accidents, and falls. Blows to the head and gunshot wounds, particularly those that injure brain membranes and tissues, can lead to epilepsy. In general, the more severe the injury, the greater the chance of developing the disease.
  • Brain tumor or stroke. Either can lead to injury or irritation of brain tissue.
  • Metabolic abnormalities. Complications from diabetes, kidney failure, lead poisoning, use of alcohol or drugs, or withdrawal from alcohol or drugs can cause seizures.
  • Degenerative disorders. Stroke, cardiovascular disease, and Alzheimer's disease are causes of epilepsy, particularly in people over 65.
  • Infections. Epilepsy may develop after a major brain illness such as meningitis, encephalitis, brain abscess, or severe infections of any part of the body. Less frequently, mumps, measles, and diphtheria can lead to the disease.
  • Complications of AIDS or other immune disorders, including systemic lupus erythematosus, also can cause epilepsy.

What Triggers a Seizure?

Anyone can have a seizure, but a person with epilepsy has many more seizures and experiences them over a longer period of time. For a person with epilepsy, many conditions that affect the brain can trigger a seizure. These triggers include: hormonal changes, such as those that occur during the menstrual cycle or pregnancy; hunger; exhaustion or sleep deprivation; rhythmic patterns of sound, touch, or light (particularly strobe lights). An epileptic seizure is not a medical emergency. However, if a person goes into status epilepticus (where a seizure lasts longer than 30 minutes or two seizures rapidly follow one another), the condition could be life threatening. Medical assistance should be summoned at once.

How Do Seizures Differ?

Because of the way they appear during or after an attack, people experiencing an epileptic seizure are sometimes mistakenly believed to be drunk, drugged, or mentally ill. Epileptic seizures have different symptoms or characteristics depending on where the seizure begins in the brain and how the electrical discharge spreads across the brain. Epileptic seizures can be divided into two categories: generalized seizures and partial seizures.

Fyodor Dostoyevsky

Fyodor Dostoyevsky (1821—1881) was a Russian writer who is considered one of the world's great novelists. With brilliant psychological and philosophical insight, Dostoyevsky examined the human soul in Notes from the Underground, Crime and Punishment, and his masterpiece in 1880, The Brothers Karamazov. Dostoyevsky had epilepsy, and his fiction includes characters with epilepsy.

Generalized seizures

Generalized seizures affect nerve cells throughout the cerebral cortex (the cauliflower-like outer portion of the brain), or all of the brain. The most common generalized seizures are:

  • Generalized tonic-clonic seizure (formerly called grand mal). In the tonic phase of this seizure, people often lose consciousness, drop to the ground, and emit a loud cry as air is forced through their vocal cords. In the clonic phase, body muscles can contract at once or in a series of shorter rhythmic contractions, causing the thrashing motions experienced by Erin. Usually, this kind of seizure lasts for about one or two minutes, and is followed by a period of relaxation, sleepiness, and possibly a headache. Incontinence * often occurs during this type of seizure.
  • Absence seizure (formerly called petit mal). Loss of consciousness in this seizure is often so brief that a person does not even change positions. The person may display a blank stare, rapid blinking, or chewing movements. Facial or eyelid muscles may jerk rhythmically. Absence seizures often are genetic and occur mostly in children.

Partial seizures

Partial seizures are contained within one region of the cerebral cortex. Types of partial seizures include:

  • Simple partial. In this type of seizure, the seizure-related brain messages remain very localized, and the patient is awake and alert. Symptoms vary depending on what area of the brain is involved. They may include jerking movements in one part of the body, emotional symptoms such as unexplained fear, or an experience of abnormal smells or nausea.
  • Complex partial. In this type of seizure, a person loses awareness of surroundings and is unresponsive or only partially responsive. There may be a blank stare, chewing movements, repeated swallowing, or other random activity. After the seizure, the patient has no memory of the experience. In some cases, the person who has had the seizure may suddenly become confused, begin to fumble, to wander, or to repeat inappropriate words or phrases.

How Is Epilepsy Diagnosed?

Because not every person who has a seizure necessarily has epilepsy, the doctor must determine the seizure's cause by a physical exam and medical history, including the seizures that have already occurred. Risk factors such as sleep deprivation and alcohol use need to be assessed, as well as any head injuries, childhood seizures, or family history of seizures.

Physicians also will be interested to know if the patient has experienced an aura * because that can help confirm that the seizure is a brain disorder and help establish its location. The doctor also will ask about the nature of the movements the person made during a seizure.

* Incontinence (in-KON-ti-nens) is loss of control of urination or bowel movement.

* aura is a warning sensation that precedes a seizure or other neurological event.

If it is established that the patient has experienced an epileptic seizure, the next step is to identify the type of seizure. The first tool doctors use is an electroencephalograph (e-lek-tro-en-SEF-a-lo-graf). Commonly known as an EEG, this machine records electric currents in the brain, and it can track abnormal electrical activity. If the EEG does

Epileptic seizures have different phases, as shown on these positron emission (PET) scans. The stage shown in the middle is the most severe. NCI/Photo Researchers, Inc.
Epileptic seizures have different phases, as shown on these positron emission (PET) scans. The stage shown in the middle is the most severe.
NCI/Photo Researchers, Inc.
not show the seizure activity, or if there are certain other features in the patient's physical exam or medical history, then doctors may try other types of scans, including CT (computerized tomography) or MRI (magnetic resonance imaging).

How Is Epilepsy Treated?

Treating epilepsy involves three goals: to eliminate seizures or at least reduce their frequency, to avoid side effects of long-term medical treatments, and to assist in maintaining or restoring normal activities of daily living.

Medication

Most cases of epilepsy can be fully or partially controlled with anticonvulsant medications, although some seizure disorders of infancy or early childhood may not respond well to medications. If a person is free of seizures for several years, doctors may reduce or even eliminate medication. In many cases, however, epilepsy remains a lifelong, chronic condition with no medical treatment guaranteeing remission * or a permanent cure.

Surgery

If drug therapy does not work, a surgical procedure can remove the damaged cells that cause partial seizures. To qualify, however, the tissue must be located in one small area of the brain and the surgeon must be able to remove this tissue without harming a person's mental abilities or personality. Although adults have undergone the surgery successfully, the results are usually better when the surgery is performed on children and infants.

Diet

A ketogenic diet (a doctor-monitored, high-fat, high-calorie diet) that was discontinued as a therapy when medicines became available, is being revived as a treatment. Some people believe the diet can stop seizures by creating ketosis (ke-TO-sis), a condition in which the body burns fat for energy instead of glucose. The ketogenic diet may be recommended for children who do not respond to standard treatment.

* remission is an easing of a disease or its symptoms for a prolonged period.

Biofeedback

Biofeedback has been beneficial to some patients, when combined with other therapies. Biofeedback uses electronic instruments to monitor a person's brain waves, blood pressure, heart rate, and skin temperature. This information is then "fed back" to the patient, who has been taught techniques to alter these bodily functions to a lower, more relaxed level.

New treatments

Epilepsy research is an active field. One promising technique now in development is called vagus nerve stimulation.

Can Epilepsy Be Prevented?

Because so many cases of epilepsy have no known cause, there are no prevention guidelines. However, anything that injures the brain can cause epilepsy. With that in mind, safety precautions and good health practices would include:

  • In a car, always buckling seat belts and observing speed limits.
  • Always wearing approved helmets and protective headgear while skating, bicycling, playing sports, or riding motorcycles.
  • Using drugs only as prescribed.
  • Immunizing children against infectious diseases.

Living with Epilepsy

Most people with epilepsy can lead normal and active lives, although they must follow a few safety restrictions. People with epilepsy must be free of seizures for a period of time specified by their home state before they are permitted to drive. People with uncontrolled seizures are prohibited from driving a car.

A person with a seizure disorder should avoid working in jobs that involve heights, dangerous machinery, or underwater environments. To avoid the risk of drowning during a seizure, showers are safer than baths, and swimming in a pool or lake with other people is safer than swimming alone.

People with epilepsy also are at risk for depression. In part, the depression may stem from loss of mobility, or from the effects of prejudice at school or at work on the part of those who fear or do not understand the condition. Parents may be overly protective of children with epilepsy, keeping them from normal childhood activities. It is common for depressed adolescents to refuse to comply with their medication schedules, running the risk of additional seizures. Alcohol also may increase the risk of seizures for some people, and mixing alcohol with anticonvulsant medications can be deadly.

Understanding the facts about epilepsy and providing a positive environment in which treatment becomes a part of everyday life can help people with epilepsy and their families.

Medic Alert Tags

People with epilepsy often wear medical alert identification tags or bracelets that provide vital information for caregivers during seizures.

Some companies offer tags with identification numbers so that medical personnel anywhere can retrieve a patient's medical history.

Resources

Book

Wilner, Andrew N. Epilepsy: 199 Answers. A Doctor Responds to His Patients Questions. New York: Demos Vermande, 1996.

Organization

The Epilepsy Foundation, 4351 Garden Drive, Landover, MD 20785. Foundation of Epilepsy this national organization offers advocacy and resources. The website provides general information on diagnosis and treatment, plus web links and a chat room for teenagers.
Telephone 800-332-1000
http://www.epa.org

See also
Brain Tumors
Diabetes
Encephalitis
Incontinence
Kidney Disease
Lead Poisoning
Lupus
Meningitis
Seizures
Stroke



Also read article about Epilepsy from Wikipedia

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