Epilepsy

Definition

Epilepsy is a condition characterized by recurrent seizures that may include repetitive muscle jerking called convulsions. A seizure is a sudden disruption of the brain's normal electrical activity accompanied by altered consciousness and/or other neurological and behavioral manifestations.

Description

Epilepsy affects 1–2% of the population of the United States. Although epilepsy is as common in adults over 60 as in children under 10, 25% of all cases develop before the age of five. One in every two cases develops before the age of 25. About 125,000 new cases of epilepsy are diagnosed each year, and a significant number of children and adults that have not been diagnosed or treated have epilepsy.

Most seizures are benign, but a seizure that lasts a long time can lead to status epilepticus, a life-threatening condition characterized by continuous seizures, sustained loss of consciousness, and respiratory distress. Nonconvulsive epilepsy can impair physical coordination, vision, and other senses. Undiagnosed seizures can lead to conditions that are more serious and more difficult to manage.

Types of seizures

Generalized epileptic seizures occur when electrical abnormalities exist throughout the brain. A partial seizure does not involve the entire brain. A partial seizure begins in an area called an epileptic focus, but may spread to other parts of the brain and cause a generalized seizure. Some people who have epilepsy have more than one type of seizure.

Motor attacks cause parts of the body to jerk repeatedly. A motor attack usually lasts less than an hour and may last only a few minutes. Sensory seizures begin with numbness or tingling in one area. The sensation may move along one side of the body or the back before subsiding.

Visual seizures that affect the area of the brain that controls sight cause people to hallucinate. Auditory seizures affect the part of the brain that controls hearing and cause the patient to imagine hearing voices, music, and other sounds. Other types of seizures can cause confusion, upset stomach, or emotional distress.

PARTIAL SEIZURES. Simple partial seizures do not spread from the focal area where they arise. Symptoms are determined by the part of the brain affected. The patient usually remains conscious during the seizure and can later describe it in detail.

COMPLEX PARTIAL SEIZURES. A distinctive smell, taste, or other unusual sensation (aura) may signal the start of a complex partial seizure.

Complex partial seizures start as simple partial seizures, but move beyond the focal area and cause loss of consciousness. Complex partial seizures can become major motor seizures. Although a person having a complex partial seizure may not seem to be unconscious, he or she does not know what is happening and may behave inappropriately. He or she will not remember the seizure, but may seem confused or intoxicated for a few minutes after it ends.

Causes & symptoms

The origin of 50–70% of all cases of epilepsy is unknown. Epilepsy sometimes results from trauma at birth. Such causes include insufficient oxygen to the brain; head injury; heavy bleeding or incompatibility between a woman's blood and the blood of her newborn baby; and infection immediately before, after, or at the time of birth.

Other causes of epilepsy include:

• head trauma resulting from a car accident, gunshot wound, or other injury
• alcoholism
• brain abscess or inflammation of membranes covering the brain or spinal cord
• phenylketonuria (PKU), a disease that is present at birth, is often characterized by seizures, and can result in mental retardation
• other inherited disorders
• infectious diseases such as measles, mumps , and diphtheria
• degenerative disease
• lead poisoning, mercury poisoning, carbon monoxide poisoning, or ingestion of some other poisonous substance
• genetic factors

Status epilepticus, a condition in which a person suffers from continuous seizures and may have trouble breathing, can be caused by:

• suddenly discontinuing antiseizure medication
• hypoxic or metabolic encephalopathy (brain disease resulting from lack of oxygen or malfunctioning of other physical or chemical processes)
• acute head injury
• infection spread from blood (for example, meningitis or encephalitis) caused by inflammation of the brain or the membranes that cover it

Diagnosis

Personal and family medical history, description of seizure activity, and physical and neurological examinations help primary care physicians, neurologists, and epileptologists diagnose this disorder. Doctors rule out conditions that cause symptoms that resemble epilepsy, including small strokes (transient ischemic attacks, or TIAs), fainting (syncope), pseudoseizures, and sleep attacks (narcolepsy ).

Neuropsychological testing uncovers learning or memory problems. Neuroimaging provides views of brain areas involved in seizure activity.

The electroencephalogram (EEG) is the main test used to diagnose epilepsy. EEGs use electrodes placed on or within the skull to record the brain's electrical activity and pinpoint the exact location of abnormal discharges.

The patient may be asked to remain motionless during a short-term EEG or to go about his normal activities during extended monitoring. Some patients are deprived of sleep or exposed to seizure triggers, such as rapid, deep breathing (hyperventilation) or flashing lights (photic stimulation). In some cases, people may be hospitalized for EEG monitorings that can last as long as two weeks. Video EEGs also document what the patient was doing when the seizure occurred and how the seizure changed his or her behavior.

Other techniques used to diagnose epilepsy include:

• Magnetic resonance imaging (MRI), which provides clear, detailed images of the brain. Functional MRI (fMRI), performed while the patient does various tasks, can measure shifts in electrical intensity and blood flow and indicate which brain region each activity affects.
• Positron emission tomography (PET) and single photon emission tomography (SPECT) monitor blood flow and chemical activity in the brain area being tested. PET and SPECT are very effective in locating the brain region where metabolic changes take place between seizures.

Treatment

Relaxation techniques

Stress increases seizure activity in 30% of people who have epilepsy. Relaxation techniques can provide some sense of control over the disorder, but they should never be used instead of antiseizure medication or without the approval of the patient's doctor. Yoga, meditation , and favorite pastimes help some people relax and manage stress more successfully. Biofeedback can teach adults and older adolescents how to recognize an aura and what to do to stop its spread. Children under 14 usually are not able to understand and apply principles of biofeedback.

Acupuncture

Acupuncture treatments (acupuncture needles inserted for a few minutes or left in place for as long as 30 minutes) make some people feel pleasantly relaxed.

Acupressure

Acupressure can have the same effect on children or on adults who dislike needles.

Aromatherapy

Aromatherapy involves mixing aromatic plant oils into water or other oils and massaging them into the skin or using a special burner to waft their fragrance throughout the room. Aromatherapy oils affect the body and the brain, and undiluted oils should never be applied directly to the skin. Ylang ylang, chamomile , or lavender can create a soothing mood. People who have epilepsy should not use rosemary, hyssop , citrus (such as lemon), sage , or sweet fennel , which seem to stimulate the brain.

Nutritional therapy

KETOGENIC DIET. A special high-fat, low-protein, low-carbohydrate diet is sometimes used to treat patients whose severe seizures have not responded to other treatment. Calculated according to age, height, and weight, the ketogenic diet induces mild starvation and dehydration. This forces the body to create an excessive supply of ketones, natural chemicals with seizure-suppressing properties.

The goal of this controversial approach is to maintain or improve seizure control while reducing medication. The ketogenic diet works best with children between the ages of one and 10. It is introduced over a period of several days, and most children are hospitalized during the early stages of treatment.

If a child following this diet remains seizure-free for at least six months, increased amounts of carbohydrates and protein are gradually added. If the child shows no improvement after three months, the diet is gradually discontinued. A 2003 study of the diet and its effect on growth noted that if used, clinicians should recommend adequate intake of energy and protein and a higher proportion of unsaturated to saturated dietary fats. The report also recommended use of vitamin and mineral supplements with the diet.

Introduced in the 1920s, the ketogenic diet has had limited, short–term success in controlling seizure activity. Its use exposes patients to such potentially harmful side effects as:

• staphylococcal infections
• stunted or delayed growth
• low blood sugar (hypoglycemia)
• excess fat in the blood (hyperlipidemia)
• disease resulting from calcium deposits in the urinary tract (urolithiasis)
• disease of the optic nerve (optic neuropathy)

Homeopathy

Homeopathic therapy also can work for people with seizures, especially constitutional homeopathic treatment that acts at the deepest levels to address the needs of the individual person.

Allopathic treatment

The goal of epilepsy treatment is to eliminate seizures or make the symptoms less frequent and less severe. Long-term anticonvulsant drug therapy is the most common form of epilepsy treatment.

Medication

A combination of drugs may be needed to control some symptoms, but most patients who have epilepsy take one of the following medications:

• Dilantin (phenytoin)
• Tegretol (carbamazepine)
• Barbita (phenobarbital)
• Mysoline (primidone)
• Depakene (valproic acid, sodium valproate)
• Klonopin (clonazepam)
• Zarontin (ethosuximide)

Dilantin, Tegretol, Barbita, and Mysoline are used to manage or control generalized tonic-clonic and complex partial seizures. Depakene, Klonopin, and Zarontin are prescribed for patients who have absence seizures.

Neurontin (gabapentin), Lamictal (lamotrigine), and topiramate (Topamax) are among medications more recently approved in the United States to treat adults who have partial seizures or partial and grand mal seizures. Another new medication called Levetiracetam (Keppra) has been approved and shows particularly good results in reducing partial seizures among elderly patients with few side effects. This is important, because elderly patients often have other conditions and must take other medications that might interact with seizure medications. In 2003, Keppra's manufacturer was working on a new antiepilectic drug from the same chemical family as Keppra that should be more potent and effective. Available medications frequently change, and the physician will determine the best treatment for an individual patient. A 2003 report found that monotherapy, or using just one medication rather than a combination, works better for most patients. The less complicated the treatment, the more likely the patient will comply and better manager the seizure disorder.

Even an epileptic patient whose seizures are well controlled should have regular blood tests to measure levels of antiseizure medication in his or her system and to check to see if the medication is causing any changes in his or her blood or liver. A doctor should be notified if any signs of drug toxicity appear, including uncontrolled eye movements; sluggishness, dizziness , or hyperactivity; inability to see clearly or speak distinctly; nausea or vomiting ; or sleep problems.

Status epilepticus requires emergency treatment, usually with Valium (Ativan), Dilantin, or Barbita. An intravenous dextrose (sugar) solution is given to a patient whose condition is due to low blood sugar, and a vitamin B₁ preparation is administered intravenously when status epilepticus results from chronic alcohol withdrawal. Because dextrose and thiamine are essentially harmless and because delay in treatment can be disastrous, these medications are given routinely, as it is usually difficult to obtain an adequate history from a patient suffering from status epilepticus.

Intractable seizures are seizures that cannot be controlled with medication or without sedation or other unacceptable side effects. Surgery may be used to eliminate or control intractable seizures.

Surgery

Surgery can be used to treat patients whose intractable seizures stem from small focal lesions that can be removed without endangering the patient, changing the patient's personality, dulling the patient's senses, or reducing the patient's ability to function.

A physical examination is conducted to verify that a patient's seizures are caused by epilepsy, and surgery is not used to treat patients with severe psychiatric disturbances or medical problems that raise risk factors to unacceptable levels.

Surgery is never recommended unless:

• The best available antiseizure medications have failed to control the patient's symptoms satisfactorily.
• The origin of the patient's seizures has been precisely located.
• There is good reason to believe that surgery will significantly improve the patient's health and quality of life.

Every patient considering epilepsy surgery is carefully evaluated by one or more neurologists, neurosurgeons, neuropsychologists, and/or social workers. A psychiatrist, chaplain, or other spiritual advisor may help the patient and his family cope with the stresses that occur during and after the selection process.

TYPES OF SURGERY. Surgical techniques used to treat intractable epilepsy include:

• Lesionectomy. Removing the lesion (diseased brain tissue) and some surrounding brain tissue is very effective in controlling seizures. Lesionectomy is generally more successful than surgery performed on patients whose seizures are not caused by clearly defined lesions, but removing only part of the lesion lessens the effectiveness of the procedure.
• Temporal resections. Removing part of the temporal lobe and the part of the brain associated with feelings, memory, and emotions (the hippocampus) provides good or excellent seizure control in 75–80% of properly selected patients with appropriate types of temporal lobe epilepsy. Some patients experience post-operative speech and memory problems.
• Extra-temporal resection. This procedure involves removing some or all of the frontal lobe, the part of the brain directly behind the forehead. The frontal lobe helps regulate movement, planning, judgment, and personality. Special care must be taken to prevent post-operative problems with movement and speech. Extra-temporal resection is most successful in patients whose seizures are not widespread.
• Hemispherectomy. This method of removing brain tissue is restricted to patients with severe epilepsy and abnormal discharges that often extend from one side of the brain to the other. Hemispherectomies are most often performed on infants or young children who have had an extensive brain disease or disorder since birth or from a very young age.
• Corpus callosotomy. This procedure, an alternative to hemispherectomy in patients with congenital hemiplegia, removes some or all of the white matter that separates the two halves of the brain. Corpus callosotomy is performed almost exclusively on children who are frequently injured during falls caused by seizures. If removing two–thirds of the corpus callosum does not produce lasting improvement in the patient's condition, the remaining one-third will be removed during another operation.
• Multiple subpial transection. This procedure is used to control the spread of seizures that originate in or affect the "eloquent" cortex, the area of the brain responsible for complex thought and reasoning.

Other forms of treatment

VAGUS NERVE STIMULATION. Approved for adults and adolescents (over 16 years old) with intractable seizures, vagus nerve stimulation (VNS) uses a pacemaker-like device implanted under the skin in the upper left chest, to provide intermittent stimulation to the vagus nerve. Stretching from the side of the neck into the brain, the vagus nerve affects swallowing, speech, breathing, and many other functions, and VNS may prevent or shorten some seizures.

First aid for seizures

A person with epilepsy having a seizure should not be restrained, but sharp or dangerous objects should be moved out of reach. Anyone having a complex partial seizure can be warned away from danger by someone calling his/her name in a clear, calm voice.

A person with epilepsy having a grand mal seizure should be helped to lie down, and those aiding the patient should contact emergency medical personnel. Tight clothing should be loosened. A soft, flat object like a towel or the palm of a hand should be placed under the person's head. Forcing a hard object into the mouth of someone having a grand mal seizure could cause injuries or breathing problems. If the person's mouth is open, placing a folded cloth or other soft object between his or her teeth will protect the tongue. Turning the patient's head to the side will help with breathing. After a grand mal seizure has ended, the person who had the seizure should be told what has happened and reminded of where he or she is.

Expected results

People who have epilepsy have a higher than average rate of suicide; sudden, unexplained death; and drowning and other accidental fatalities.

Benign focal epilepsy of childhood and some absence seizures may disappear in time, but remission is unlikely if seizures occur several times a day, several times in a 48-hour period, or more frequently than in the past.

Epilepsy can be partially or completely controlled if the individual takes antiseizure medication according to directions; avoids seizure-inducing sights, sounds, and other triggers; gets enough sleep; and eats regular, balanced meals.

Anyone who has epilepsy should wear a bracelet or necklace identifying the seizure disorder and listing the medication he or she takes.

Prevention

Eating properly, getting enough sleep, and controlling stress and fevers can help prevent seizures. A person who has epilepsy should be careful not to hyperventilate. Those who experience auras should find a safe place to lie down and stay until the seizure passes. Anticonvulsant medications should not be stopped suddenly and, if other medications are prescribed or discontinued, the doctor treating the seizures should be notified. In some conditions, such as severe head injury, brain surgery, or subarachnoid hemorrhage, anticonvulsant medications may be given to the patient to prevent seizures.

Resources

BOOKS

"Seizures." Reader's Digest Guide to Medical Cures & Treatments : A Complete A-to-Z Sourcebook of Medical Treatments, Alternative Opinions, and Home Remedies. Canada: The Reader's Digest Association, Inc., 1996.

Shaw, Michael, ed. Everything You Need to Know about Diseases. Springhouse, PA: Springhouse Corporation, 1996.

PERIODICALS

Batchelor, Lori, et al. "An Interdisciplinary Approach to Implementing the Ketogenic Diet for the Treatment of Seizures." Pediatric Nursing (September/October 1997): 465–471.

"Data Analysis Shows Keppra Reduced Partial Seizures in Elderly Patients." Clinical Trials Week (April 28, 2003): 26.

Dichter, M.A., and M.J. Brodie. "Drug Therapy: New Antiepileptic Drugs." The New England Journal of Medicine (15 June 1996): 1583-1588.

Dilorio, Colleen, et al. "The Epilelpsy Medication and Treatment Complexity Index: Reliability and Validity Testing." Journal of Neuroscience Nursing (June 2003): 155–158.

"Epilepsy Surgery and Vagus Nerve Stimulation Are Effective When Drugs Fail." Medical Devices & Surgical Technology Week (May 4, 2003): 33.

Finn, Robert. "Partial Seizures Double Risk of Sleep Disturbances (Consider in Diagnosis, Management)." Clinical Psychiatry News (June 2003): 36–41.

Lannox, Susan L. "Epilepsy Surgery for Partial Seizures." Pediatric Nursing (September–October 1997): 453-458.

Liu, Yeou-Mei Christiana, et al. "A Prospetive Study: Growth and Nutritional Status of Children Treated With the Ketogenic Diet." Journal of the American Dietetic Association (June 2003): 707.

McDonald, Melori E. "Use of the Ketogenic Diet in Treating Children with Seizures." Pediatric Nursing (September-October 1997): 461-463.

"New Drug Candidate Shows Promise." Clinical Trials Week (April 7, 2003): 26.

ORGANIZATIONS

American Epilepsy Society. 638 Prospect Avenue, Hartford, CT 06105-4298. (205) 232-4825.

Epilepsy Concern International Service Group. 1282 Wynnewood Drive, West Palm Beach, FL 33417. (407) 683–0044.

Epilepsy Foundation of America. 4251 Garden City Drive, Landover, MD 20875-2267. (800) 532-1000.

Epilepsy Information Service. (800) 642-0500.

OTHER

Bourgeois, Blaise F.D. Epilepsy Surgery in Children. http://www.neuro.wustl.edu/epilepsy/21children.html (3 March 1998).

Cosgrove, G. Rees, and Andrew J. Cole. Surgical Treatment of Epilepsy. http://neurosurgery.mgh.harvard.edu/ep-sxtre.htm (3 March 1998).

Epilepsy. http://www.ninds.nih.gov/healinfo/disorder/epilepsy/epilepfs.htm (28 February 1998).

Epilepsy and Dental Health. http://www.epinet.org.au/efvdent.html (3 March 1998).

Epilepsy Facts and Figures. http://www.efa.org/what/education/FACTS.html (28 February 1998).

Frequently Asked Questions (FAQs) About the Ketogenic Diet. http://www-leland.Stanford.edu/group/ketodiet/FAQ.html (28 February 1998).

Surgery for Epilepsy: NIH Consensus Statement Online. http://neurosurgery.mgh.harvard.edu/epil-nih.htm (3 March 1998).

The USC Vagus Nerve Stimulator Program. http://www.usc.edu/hsc/medicine/neurology/VNS.html (3 March 1998).

Mai Tran

Teresa G. Odle

Epilepsy

Definition

The words "epilepsy" and "epileptic" are of Greek origin and have the same root as the verb "epilambanein," which means "to seize" or "to attack." Therefore, epilepsy means seizure, while epileptic means seized. In the modern understanding of epilepsy, it should not be considered a disease. Rather, it is a symptom indicating a medical condition in the brain that causes a potential for recurrent seizures . The condition of epilepsy has many causes and the kinds of seizures that occur can vary widely.

Description

The word epilepsy is actually a descriptive term. It takes into account an individual's risk of recurrent seizures. However, when people are suffering from meningitis and have a seizure, they would not be considered to have epilepsy unless they had a seizure after the meningitis resolved. In this case, these individuals have a risk for recurrent seizures and, hence, epilepsy. If an individual over time does not have any seizures off medications, then it could be said that epilepsy has resolved or gone into remission.

For thousands of years, epilepsy was looked upon differently than most other medical problems. Because of this, epilepsy has been fraught with social stigmas, even up to today. The ancient Greeks knew about the condition that led to a sudden attack upon the unfortunate. Although Hippocrates, in roughly 400 b.c., referred to epilepsy as the sacred disease, he did so to emphasize the general public's superstitious view of the condition. Of course, it certainly was not an affliction sent from a deity, nor was it even a demon. Nevertheless, seizures, which manifest in unusual behaviors, mystified observers who considered this illness, from all others, as coming from another world.

The current understanding of epilepsy is a recent development. Previously, it was not even believed that the brain had electrical properties. It was not until the last few centuries that the brain was considered the seat of the mind; it was the heart or the lungs that were commonly regarded as the organ of thought. Physicians struggled with what to even call a seizure. In general, any behavior that resulted in a loss of consciousness or convulsions was labeled a seizure. It is likely that episodes of fainting were erroneously called seizures.

Finally, in 1873, an adequate definition for the term seizure finally came into existence. The famous English neurologist John Hughlings Jackson explained epilepsy as "a sudden, excessive, and rapid discharge of gray matter of some part of the brain" that would correspond to the patient's experience.

Demographics

More than 2.5 million Americans suffer from epilepsy, and more than another 50 million worldwide. Epilepsy is more common than Parkinson's disease , multiple sclerosis , cerebral palsy , and muscular dystrophy all combined. The risk of experiencing one seizure in the course of a lifetime, from any cause, is close to 10%. However, there is an approximately 1% chance of developing epilepsy in the general population before the age of 20. The risk increases to 3% by age 75. Of course, depending on the age group being studied, the cause of epilepsy will vary. The incidence of epilepsy is relatively constant among different ethnic groups and similar between genders. However, there may be variation in incidence in underdeveloped countries due to access to care and endemic illness that can cause seizures, such as neurocystercercosis in Latin American countries.

Causes and symptoms

Epilepsy has many causes that, in part, have an affect on the clinical presentation of symptoms. In order for epilepsy to occur, there must be an underlying physical problem in the brain. The problem can be so mild that an individual is perfectly normal other than seizures. The brain has roughly 50–100 billion neurons. Each neuron can have up to 10,000 contacts with neighboring neurons. Hence, trillions of connections exist. However, only a very small area of dysfunctional brain tissue is necessary to create a persistent generator of seizures and, hence, epilepsy. The following are potential causes of epilepsy:

• genetic and/or hereditary
• perinatal neurological insults
• trauma with brain injury
• stroke
• brain tumors
• infections such as meningitis and encephalitis
• multiple sclerosis
• ideopathic (unknown or genetic)

Any of the above conditions have the potential for causing the brain or a portion of it to be dysfunctional and produce recurrent seizures. Regardless of the exact cause, epilepsy is a paroxysmal (sudden) condition. It involves the synchronous discharging of a population of neurons. This is an abnormal event that, depending on the location in the brain, will correspond to the particular symptoms of a seizure. The International League Against Epilepsy (ILAE) issued a classification of types of seizures. The list gives the kind of seizures that can occur. Individual seizure types are based on the clinical behavior (semiology) and electrophysiological characteristics as seen on an electroencephalogram (EEG). Generalized seizures included in the list are:

• tonic-clonic seizures (includes variations beginning with a clonic or myoclonic phase)
• clonic seizures, including without tonic features and with tonic features
• typical absence seizures
• atypical absence seizures
• myoclonic absence seizures
• tonic seizures
• spasms
• myoclonic seizures
• eyelid myoclonia, including without absences and with absences
• myoclonic atonic seizures
• negative myoclonus atonic seizures
• reflex seizures in generalized epilepsy syndromes

Focal seizures included in the ILAE list are:

• focal sensory seizures with elementary sensory symptoms (e.g., occipital and parietal lobe seizures) and experiential sensory symptoms (e.g., temporo-parieto-occipital junction seizures)
• focal motor seizures with elementary clonic motor signs, asymmetrical tonic motor seizures (e.g., supplementary motor seizures), typical (temporal lobe) automatisms (e.g., mesial temporal lobe seizures), hyperkinetic automatisms, focal negative myoclonus, and inhibitory motor seizures
• gelastic seizures
• hemiclonic seizures
• secondarily generalized seizures
• reflex seizures in focal epilepsy syndromes

In 1989, the International League Against Epilepsy also issued the following classification of epilepsies and epileptic syndromes:

• benign familial neonatal seizures
• early myoclonic encephalopathy
• Ohtahara syndrome
• migrating partial seizures of infancy (syndrome in development)
• West syndrome
• benign myoclonic epilepsy in infancy
• benign familial and non-familial infantile seizures
• Dravet's syndrome
• HH syndrome
• myoclonic status in nonprogressive encephalopathies (syndrome in development)
• benign childhood epilepsy with centrotemporal spikes
• early onset benign childhood occipital epilepsy (Panayiotopoulos type)
• late-onset childhood occipital epilepsy (Gastaut type)
• epilepsy with myoclonic absences
• epilepsy with myoclonic-astatic seizures
• Lennox-Gastaut syndrome
• Landau-Kleffner syndrome (LKS)
• epilepsy with continuous spike-and-waves during slow-wave sleep (other than LKS)
• childhood absence epilepsy
• progressive myoclonus epilepsies
• idiopathic generalized epilepsies with variable phenotypes include juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures only
• reflex epilepsies
• idiopathic photosensitive occipital lobe epilepsy
• other visual sensitive epilepsies
• primary reading epilepsy
• startle epilepsy
• autosomal dominant nocturnal frontal lobe epilepsy
• familial temporal lobe epilepsies
• generalized epilepsies with febrile seizures plus (syndrome in development)
• familial focal epilepsy with variable foci (syndrome in development)
• symptomatic focal epilepsies
• limbic epilepsies
• mesial temporal lobe epilepsy with hippocampal sclerosis
• mesial temporal lobe epilepsy defined by specific etiologies
• neocortical epilepsies
• Rasmussen syndrome

Classifying epilepsy can help in the evaluation and management of patients with seizure disorders. The combination of seizure type(s), etiology (cause), age of onset,

family history, and other medical or neurological conditions can be used to identify an epilepsy syndrome. Classification helps clinicians and researchers understand the broader picture of seizure disorders. On a practical level, syndrome identification can help in planning the management of patients. Syndrome classification schemes are revised periodically as individual components of particular categories are better understood.

The term idiopathic refers to a cause that is suspected to be, if not genetic, then unknown. Cryptogenic is a term that suggests that an underlying cause is suspected, but not yet fully understood. Symptomatic is a term that is applied to epilepsies that are a result of understood underlying pathologies.

The management and prognosis vary considerably among these differing syndromes. Epilepsies that have a genetic basis can be inherited or occur spontaneously. A detailed family history can often identify other family members who have had seizures. However, because seizures are common, it is possible to have more than one family member with epilepsy, though the etiologies may not be related. To say that a particular type of epilepsy is genetic does not mean that it is necessarily transmitted by heredity. Often, disorders can have a genetic cause, but be spontaneously occurring in only one member of a family. In this case, there may simply be a random mutation in that particular person's genes.

There are several mechanisms in which epilepsies can be inherited. So-called simple Mendelian inheritance occurs with benign familial neonatal convulsions and autosomal dominant nocturnal frontal lobe epilepsy. On the other hand, complex inheritance mechanisms can involve more than one gene, or a gene mutation in combination with environmental or acquired factors such as juvenile myoclonic epilepsy. As the genetics of the epilepsies become better understood, the classification scheme will evolve.

With epilepsy, symptoms vary considerably depending on the type. The common link among the epilepsies is, of course, seizures. The different epilepsies can sometimes be associated with more than one seizure type. This is the case with Lennox-Gastaut syndrome.

Diagnosis

Arriving at a diagnosis of epilepsy is relatively straightforward: when people suffer two or more seizures, they would be considered to have epilepsy. However, diagnosing the specific epilepsy syndrome is much more complex. The first step in the evaluation process is to obtain a very detailed history of the illness, not only from the patient but from the family as well. Since seizures can impair consciousness, the patient may not be able to recall the specifics of the attacks. In these cases, family or friends that have witnessed the episodes can fill in the gaps about the particulars of the seizure. The description of the behaviors during a seizure can go a long way to categorizing the type of seizure and help with the overall diagnosis. Moreover, in the initial visit with the physician, the entire history of the patient is obtained. In a child, this would include birth history, complications, if any, maternal history, and developmental milestones. At any age, socalled co-morbidities (other medical problems) are considered. Medications that have been taken or currently being prescribed are documented.

A complete physical examination is performed, especially a neurological exam. Because seizures are an episodic disorder, abnormal neurological findings may not be present. Frequently, people with epilepsy have a normal exam. However, in some, there can be abnormal findings that can provide clues to the underlying cause of epilepsy. For example, if someone has had a stroke that subsequently caused seizures, then the neurological exam can be expected to reveal a focal neurological deficit such as weakness or language difficulties. In some children with seizures, there can be a variety of associated neurologic abnormalities such as mental retardation and cerebral palsy that are themselves non-specific but indicate that the brain has suffered, at some point in development, an injury or malformation. Also, subtle findings on examination can lead to a diagnosis such as in tuberous sclerosis . This is an autosomal dominantly inherited disorder associated with infantile spasms in 25% of cases. On examination, patients have so-called ash-leaf spots and adenoma sebaceum on the skin. There can also be a variety of systemic abnormalities that involve the kidneys, retina, heart, and gums, depending on severity.

In the course of evaluating epilepsy, a number of tests are typically ordered. Usually, magnetic resonance image (MRI ) of the brain is obtained. This is a scan that can help in finding many known causes of epilepsy such as tumors, strokes, trauma, and congenital malformations. However, while MRI can reveal incredible details of the brain, it cannot visualize the presence of abnormalities in the microscopic neuronal environment. Another test that is routinely ordered is an electroencephalogram (EEG). Unlike the MRI scan, this can be considered a functional test of the brain. The EEG measures the electrical activity of the brain. Some seizure disorders or epilepsies have a characteristic EEG with particular abnormalities that can help in diagnosis. Other tests that are frequently ordered are various blood tests that are also ordered in many medical conditions. These blood tests help to screen for abnormalities that can be a factor in the cause of seizures. Occasionally, genetic testing is performed in those instances where a known genetic cause is suspected and can be tested. A major concern in the course of an evaluation of epilepsy is to identify the presence of life-threatening causes such as brain tumors, infections, and cerebrovascular disease. Also, an accurate diagnosis can expedite the most effective treatment plan.

The symptoms of epilepsy are dependent in part on the particular seizures that occur and other medical problems that may be associated. Seizures, themselves, can take on a variety of features. A simple sustained twitching of an extremity could be a focal seizure. If a seizure arises in the occipital lobes of the brains, then a visual experience can occur. Aura is a term often used to describe symptoms that a person may feel prior to the loss of consciousness of a seizure. However, auras are, themselves, small focal seizures that have not spread in the brain to involve consciousness. Smells, well-formed hallucinations, tingling sensations, or nausea have each occurred in auras. The particular sensation can be a clue as to the location in the brain where a seizure starts. Focal seizures can then spread to involve other areas of the brain and lead to an alteration of consciousness, and possibly convulsions. In certain epilepsy syndromes such as Lennox-Gastaut, there can be more than one type of seizure experienced, such as atonic, atypical absence, and tonic-axial seizures.

Treatment

One challenge in predicting the course of epilepsy is that for any type, there can be a variable response to treatment. Sometimes, seizures may play a rather small role in the manifestation of a medical condition. For example, a severe head injury could result in seizures that readily respond to medication, but severe neurological impairments and disabilities may still be present. On the other hand, a different head injury may result in relatively mild neurological problems, but there may be seizures that are severe and be resistant to medications.

Whatever the case, the ultimate goals when treating epilepsy are to:

• strive for complete freedom from seizures
• have little to no side effects from medications
• be able to follow an easy regimen so that compliance with treatment can be maintained

Up to 60% of patients with epilepsy can be expected to achieve control of seizures with medication(s). However, in the remaining 40%, epilepsy appears to be resistant, to varying degrees, to medications. In these cases, the epilepsy is termed medically intractable.

Generally, the choice of medication is somewhat trial and error. There are, however, a number of considerations that guide the choice of treatment. Each medication has a particular side effect profile and mechanism of action. Some medications seem to be particularly effective for certain epilepsy syndromes. For example, juvenile myoclonic epilepsy responds well to valproic acid. On the other hand, ethosuxamide is primarily used for absence seizures.

As with any medication, individuals can have very different experiences with same drug. Consequently, it is difficult to predict the efficacy of treatment in the beginning. A key concept of treatment is to first strive for monotherapy (or single drug therapy). This simplifies treatment and minimizes the chance of side effects. Sometimes, however, two or more drugs may be necessary to achieve satisfactory control of seizures. As with any treatment, potential side effects can be worse than the disease itself. Moreover, there is little point in controlling seizures if severe side effects limit quality of life. If a seizure disorder is characterized by mild, focal, or brief symptoms that do not interfere with day-to-day life, then aggressive treatments may not be justified. Epilepsy medications do not cure epilepsy; the medications can only control the frequency and severity of seizures. A list of the most commonly used medications in the management of epilepsy includes:

• phenobarbital
• phenytoin (Dilantin, Phenytek)
• clonazepam (Klonipin)
• ethosuxamide (Zarontin)
• carbamazepine (Tegretol, Carbatrol)
• divalproex sodium (Depakote, Depakene)
• felbamate (Felbatol)
• gabapentin (Neurontin)
• lamotrigine (Lamictal)
• topiramate (Topamax)
• tiagabine (Gabatril)
• zonisamide (Zonegran)
• oxcarbazepine (Trileptal)
• leviteracetam (Keppra)

It has been found that the initial, thoughtfully chosen medication can be expected to make almost 50% of patients seizure free for extended periods of time. If the initial drug fails, another well-chosen drug may make an additional 14% of people seizure free. If that drug fails, then the likelihood of rendering someone with epilepsy seizure free is poor. This does not mean that trying more medications or combinations of them may not be successful, but rather, these statistics give the neurologist and the patient an understanding of the realities of epilepsy treatment. In cases where medications do not fully control epilepsy, it is recommended that a more extensive evaluation at a comprehensive epilepsy center be conducted where an epileptologist (a specialist in epilepsy) will more thoroughly assess the particular aspects of the seizures. When medications are clearly ineffective, the other types of therapy that can be considered are the ketogenic diet, brain surgery, and vagal nerve stimulation.

Ketogenic diet

The ketogenic diet is based on high-fat, low-carbo-hydrate, and low-protein meals. The ketogenic diet is named because of the production of ketones by the breakdown of fatty acids. The most common version of the diet involves long-chain triglycerides. These are present in whole cream, butter, and fatty meats.

The ketogenic diet is administered with the support of a nutritionist with experience in this treatment modality. It is mostly used in children with medically intractable epilepsy and whose diet can be controlled. The ketogenic diet can be considered a pharmacologic treatment. As such, there are potential side effects that limit its tolerance. This includes hair thinning, lethargy, weight loss, kidney stones, and possibly cardiac problems. Sugar-free vitamin and mineral supplementation is necessary. The diet may not be appropriate for certain individuals, particularly in children, who may have certain metabolic diseases.

Overall, the diet has been very helpful in the control of seizures in many patients. Roughly 50% of patients can hope to achieve complete control of seizures, 25% of the patients see improvements, and another 25% are non-responders. There are some patients who have an improvement in behavior. If the diet is well tolerated with good results, then it can be maintained for up to two years, followed by a careful gradual transition to regular meals.

Epilepsy surgery

Epilepsy surgery is an option in the attempt to either cure or significantly reduce the severity of medically resistant cases. It is thought that up to 100,000 patients in the United States could be potential candidates for a surgical treatment. However, only about 5,000 cases are performed throughout the United States annually. This is likely due to several factors, including the belief that any brain surgery is a last resort, the lack of awareness or understanding of the benefits of surgery, and the false hope that some medication will come along that will be effective.

There are several kinds of surgery that are available depending on the nature of the seizure disorder. A list of operations that are utilized regularly for epilepsy include:

• lobectomy
• lesionectomy
• corpus collosotomy
• multiple subpial transection
• hemispherectomy

The type of surgery that is performed depends on the nature of the individual seizure disorder. If a seizure can be localized to a particular area in the brain, then this abnormal region can potentially be surgically removed. Epileptic brain tissue is abnormal and its removal can provide a chance of a cure. Generally, surgery should be a consideration when the risk and benefits of it outweigh the long-term risks of uncontrolled epilepsy.

The approach taken in any brain surgery for epilepsy is highly individualized and great care is taken to avoid injury to essential brain tissue. The most common epilepsy surgery performed is the temporal lobectomy. Brain tumors are frequently associated with seizures. In many cases, surgery to remove the tumor is planned so that regions that may be causing seizures are removed as well. However, in many cases, epilepsy surgery cannot be done.

Vagus nerve stimulation

Another non-medicinal approach to treating epilepsy is a novel method that became available in July 1997. The Food and Drug Administration (FDA) approved the use of the vagal nerve stimulator (VNS) as add-on therapy in patients who experience seizures of partial onset. The VNS is designed to intermittently deliver small electrical stimulations to a nerve in the neck called the vagus nerve. There are two vagal nerves, one on each side of the neck near the carotid arteries, making a pair of cranial nerves (there are 12 different paired cranial nerves). The vagus nerve carries information from the brain to many parts of the thoracic and abdominal organs. The nerve also carries information from these same organs back to the brain. VNS takes advantage of this fact and, by intermittent stimulation, there is an effect on many brain areas that can be involved in seizures.

About 50% of patients experience at least 50% reduction in the frequency of their seizures. The responses to VNS range from complete control of seizures (less than 10% of patients) to no noticeable improvement. The device is not a substitute for epilepsy surgery and should be considered only after there is an evaluation for epilepsy surgery. The implantation of the device requires relatively minor surgery with two incisions, one in the neck and the other in the left upper chest area.

The battery in the device lasts up to eight to ten years, after which the device can be replaced. Side effects of VNS therapy include voice hoarseness that typically does not impair communication. Like any surgery, there is an initial risk of infection, bleeding, and pain . Recovery takes a few weeks. Individuals can return to their usual activities once the incisions have healed.

Clinical trials

The National Institute of Neurological Disorders and Stroke list a number of clinical trials . There are also a number of studies being conducted at a more basic science stage evaluating the role of the following in seizures and epilepsy: neurotransmitters , non-neuronal cells, and genetic factors. Treatment strategies including deep brain stimulation and intracranial early seizure detection devices are being studied at different stages.

Prognosis

The prognosis of epilepsy varies widely depending on the cause, severity, and patient's age. Even individuals with a similar diagnosis may have different experiences with treatment. For example, in benign epilepsy of childhood with centrotemporal spikes (also called benign rolandic epilepsy), the prognosis is excellent with nearly all children experiencing remission by their teens. With childhood absence epilepsy, the prognosis is variable. In this case, the absence seizures become less frequent with time, but almost half of patients may eventually develop generalized tonic-clonic seizures. Overall, the seizures are responsive to an appropriate anticonvulsant. On the other hand, the seizures in Lennox-Gastaut syndrome are very difficult to control. In this case, however, the ketogenic diet can help. In seizures that begin in adulthood, one can expect that medications will control seizures in up to 60–70% of cases. However, in some of the more than 30% of medically intractable cases, epilepsy surgery can improve or even cure the problem.

Overall, most patients have a good chance of controlling seizures with the available options of treatment. The goal of treatment is complete cessation of seizures since a mere reduction in seizure frequency and/or severity may continue to limit patients'quality of life: they may not be able to drive, sustain employment, or be productive in school.

Resources

BOOKS

Browne, T. R., and G. L. Holmes. Handbook of Epilepsy, 2nd edition. Philadelphia: Lippincott Williams & Wilkins. 2000.

Devinski, O. A Guide to Understanding and Living with Epilepsy. Philadelphia: F.A. Davis Company. 1994.

Engel, J., Jr., and T. A. Pedley. Epilepsy: A Comprehensive Textbook. Philadelphia: Lippincott-Raven. 1998.

Freeman, M. J., et al. The Ketogenic Diet: A Treatment for Epilepsy, 3rd Edition. New York: Demos Medical Publishing, 2000.

Hauser, W. A., and D. Hesdorffer. Epilepsy: Frequency, Causes, and Consequences. New York: Demos Medical Publishing, 1990.

Pellock, J. M., W. E. Dodson, and B. F. D. Bourgeois. Pediatric Epilepsy Diagnosis and Therapy, 2nd Edition. New York: Demos Medical Publishing, 2001.

Santilli, N. Managing Seizure Disorders: A Handbook for Health Care Professionals. Philadelphia: Lippincott-Raven. 1996.

Schachter, S. C., and D. Schmidt. Vagus Nerve Stimulation, 2nd Edition. Oxford, England: Martin Dunitz, 2003.

Wyllie, E. The Treatment of Epilepsy: Principles and Practice, 3rd Edition. Philadelphia: Lippincott Williams & Wilkins, 2001.

PERIODICALS

Kwan, P., and M. J. Brodie. "Early Identification of Refractory Epilepsy." New England Journal of Medicine no. 342 (2000): 314–319.

ORGANIZATIONS

American Epilepsy Society. 342 North Main Street, West Hartford, CT 06117-2507. 860.586.7505. <www.aesnet.org>.

Epilepsy Foundation of America. 4351 Garden City Drive, Landover, MD 20785-7223. (800) 332-1000. <www.epilepsyfoundation.org>.

International League Against Epilepsy. Avenue Marcel Thiry 204, B-1200, Brussels, Belgium. + 32 (0) 2 774 9547; Fax: + 32 (0) 2 774 9690. <www.epilepsy.org>.

Roy Sucholeiki, MD

Epilepsy

Erin’s Story

What Is Epilepsy?

What Causes Epilepsy?

What Triggers a Seizure?

How Do Seizures Differ?

How Is Epilepsy Diagnosed?

How Is Epilepsy Treated?

Can Epilepsy Be Prevented?

Living with Epilepsy

Resources

Epilepsy (EP-i-lep-see) is a condition of the nervous system characterized by recurrent seizures that temporarily affect a persons 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.

KEYWORDS

for searching the Internet and other reference sources

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.

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.

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.

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.

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.

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.

• 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.

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.

* incontinence

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

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.

* 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

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.

* remission

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

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.

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.

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.

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.

See also

Diabetes

Encephalitis

Incontinence

Kidney Disease

Lead Poisoning

Lupus

Meningitis

Seizures

Stroke

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. Formerly the Epilepsy Foundation of America, 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

EPILEPSY

DEFINITION

Epilepsy is a seizure disorder. A seizure is an event that involves loss of consciousness and motor (muscular) control. A person with a seizure disorder often experiences repetitive muscle jerking called convulsions. The condition is caused by a sudden change in electrical activity in the brain.

DESCRIPTION

The medical profession now recognizes about twenty different kinds of epilepsy. These forms of the disorder vary on the basis of severity and the parts of the body affected by the seizure. Most patients have only one form of epilepsy. About 30 percent have two or more forms of the disorder.

Experts estimate that about 2 percent of the general population has some form of epilepsy. One in ten Americans experience at least one epileptic seizure at some time in their lives. At least 200,000 Americans have at least one seizure a month.

About 125,000 new cases of epilepsy are diagnosed in the United States each year. About a quarter of those cases are diagnosed in children younger than five years old.

The two most common types of epilepsy are called tonic-clonic seizures and absence seizures. At one time, these forms of the disorder were better known as grand mal ("great illness") and petit mal ("small illness"). About 90 percent of people with epilepsy experience tonic-clonic seizures, and 25 percent experience absence seizures. Less than 20 percent of patients experience other forms of epilepsy alone or in various combinations.

CAUSES

The brain contains a mass of neurons (nerve cells) that constantly communicate with each other. They communicate in two ways: by sending certain chemicals back and forth, and by the passage of electric currents among them. Under certain conditions, those electric currents can be disrupted. Instead of traveling smoothly between neurons, they go out of control.

When this happens, messages traveling through the brain are wildly disrupted. The brain begins to send out irregular and unpredictable messages to the rest of the body. Muscles throughout the body begin to contract and relax in random patterns. These changes bring about the symptoms of epilepsy.

Epilepsy: Words to Know

Aura:

A set of warning signals that an epileptic attack is about to begin.

Clonic phase:

The stage of a grand mal attack in which muscles alternately contract and relax.

Electroencephalogram (EEG):

A test used to measure electrical activity of the brain to see if the brain is functioning normally.

Grand mal:

An alternative term used for tonic-clonic epilepsy.

Idiopathic epilepsy:

A form of epilepsy for which no cause is known.

Neuron:

A nerve cell.

Petit mal:

An alternative term used for absence epilepsy.

Seizure:

A convulsion; a series of involuntary muscular movements that alternate between contractions and relaxations.

Symptomatic epilepsy:

A form of epilepsy for which some specific cause is known.

Tonic phase:

The stage of a grand mal attack in which muscles become rigid and fixed.

Epilepsy is usually classified as symptomatic or idiopathic (pronounced ih-dee-uh-PA-thik). Symptomatic epilepsy is a form of the condition for which a cause is known. For example, a person may receive a blow to the head. The injury may cause damage that leads to the development of epilepsy. Some conditions that can cause symptomatic epilepsy include:

• Serious infections of the central nervous system
• Heat stroke (see heat disorders entry)
• An abscess (open sore) in the brain
• Rabies, tetanus, and malaria (see entries)
• Toxic (poisonous) materials, such as lead or alcohol
• Damage to the brain or skull (see head injury entry)
• Drug allergy
• Stroke (see stroke entry)

Idiopathic epilepsy is epilepsy for which no specific cause has been identified. Some authorities believe that idiopathic epilepsy is caused by damage to a newborn baby's brain during delivery.

About 75 percent of all cases of epilepsy are idiopathic. Individuals with this condition usually experience their first seizure between the ages of two and fourteen. Symptomatic epilepsy usually does not appear until later in life, after the age of twenty-five.

SYMPTOMS

Symptoms vary depending on the type of seizure.

Tonic-clonic Seizures

A person who is about to have a tonic-clonic seizure often has a warning. That warning is called an aura. During the aura, the patient may emit a loud cry. The attack actually begins when the person loses consciousness and falls to the ground. His or her muscles become rigid for about thirty seconds. This period is known as the tonic phase of the disorder. The muscles then alternately contract and relax, causing the patient to thrash about. This phase of the attack is known as the clonic stage. The patient may also lose control of his or her bladder or bowels, or have trouble breathing.

A tonic-clonic attack usually lasts between two and five minutes. After the attack, the patient may be confused or have trouble talking. He or she may complain of headache or muscle soreness or weakness in the arms or legs. In some cases, the patient may fall into a deep sleep.

Absence Seizure

An absence seizure is a milder form of a tonic-clonic seizure. An absence seizure usually begins with a brief loss of consciousness. This phase of the attack lasts between one and ten seconds. Patients may become very quiet. They may stare blankly, roll their eyes, or move their lips. The whole attack is usually over in fewer than twenty seconds.

After an absence seizure, patients generally do not remember anything about the event. They just continue with whatever they were doing before the attack began. They may not realize that anything unusual has taken place. In cases of absence seizures that are not treated, a patient may experience as many as one hundred attacks a day. Eventually, the condition may progress to the tonic-clonic form of epilepsy.

DIAGNOSIS

The first goal of diagnosis is to eliminate other possible causes of the patient's symptoms. Other disorders of the brain, such as small strokes, fainting, and sleep disorders (see sleep disorders entry), can be confused with seizure disorders. A doctor needs to eliminate these possibilities before deciding how to treat the patient.

One goal of diagnosis is to distinguish between symptomatic and idiopathic epilepsy. In symptomatic epilepsy, it may be possible to provide treatment to cure the disorder. For example, a person may have had a severe allergic reaction to a food or drug. The allergic reaction may be responsible for the epileptic attack. This type of case can be treated by avoiding whatever

caused the attack in the first place. In cases of idiopathic epilepsy, where a cause is not found, other types of treatment are necessary.

The primary means of diagnosing epilepsy is the electroencephalogram (EEG, pronounced ih-LEK-tro-in-SEH-fuh-lo-gram). The EEG is a device that measures electrical activity in the brain. The results obtained from an EEG test are recorded on graph paper as a pattern of wavy lines. A doctor is able to read the lines on the paper and determine whether or not the brain is functioning normally. Seizure disorders produce characteristic patterns in an EEG test.

Doctors may try to schedule an EEG test during a seizure. They know that flashing lights (like strobe lights) or forcing the patient to breathe very deeply can trigger a seizure in patients with epilepsy. Or the patient may simply be kept in the hospital until an attack occurs. In such cases, the electrical activity of the brain during an attack can be observed and recorded.

TREATMENT

Cases of symptomatic epilepsy are treated by treating the basic cause that brought on the seizure disorder. Treatment of idiopathic epilepsy involves two steps. The first step involves protecting the patient during an attack. The second step involves the use of medications to reduce the frequency and severity of symptoms.

Patients with absence epilepsy usually require little protection. They may need help in case they lose consciousness for long enough to lose their balance and fall. Attacks of tonic-clonic epilepsy require somewhat more attention. The patient should be made comfortable during an attack by loosening clothing around the neck and providing a pillow under the head. A soft object, such as a folded handkerchief, should be placed between the teeth. The object prevents the patient from biting his or her tongue. No effort should be made to hold the tongue, however.

Several medications are now available for the treatment of epilepsy. Most of these drugs fall into the category of anticonvulsants. That is, they tend to prevent or minimize the shaking and thrashing that accompanies a seizure. Some examples of these drugs are phenobarbital (pronounced FEE-no-bar-bih-tall), primi-done (pronounced PRIM-ih-doan), trimethadione

(pronounced TRI-meth-uh-DIE-own), and valproate (pronounced val-PRO-ate).

No one drug is effective for all patients or for any one form of epilepsy. In fact, effective treatment of epilepsy requires finding exactly the right dose of exactly the right drug (or combination of drugs) for each individual patient. Most patients go through a period of testing in which various drugs in various combinations are tried. Eventually, the most suitable dose and combination are determined.

Medications have made it possible for most patients with epilepsy to lead relatively normal lives. However, there is one problem with drug therapy. Many drugs have side effects that can range from mild to severe for any one patient. The most common side effects are drowsiness, nausea, lethargy, and skin rash.

An important aspect of treating epilepsy is teaching the patient and his or her family how to live with the disorder. Patients are encouraged to pursue a normal life with moderate exercise and regular social activities. Families are encouraged not to become overprotective and, insofar as possible, to treat the patient as if he or she had no disorder.

Surgery

Intractable seizures are seizures that cannot be controlled without medication or without sedation or other unacceptable side effects. Surgery may be used to eliminate or control intractable seizures. This treatment is not very common as only seizures meeting very specific criteria can be controlled this way.

Alternative Treatment

Relaxation techniques can help people with epilepsy avoid some of the pressures that may bring on an attack. Yoga, meditation, hydrotherapy, aromatherapy, and acupressure may be helpful in this regard. These approaches, however, should never be substituted for the patient's regular program of medication.

For people with symptomatic epilepsy, dietary changes may be essential. Patients may need to identify the foods to which they are allergic and then eliminate those foods from their diets.

PROGNOSIS

The prognosis for most patients with epilepsy today is good. The most severe symptoms of the disorder can usually be controlled by the proper program of medications. Educating the patient about his or her condition can increase the chance that attacks will be handled properly and will not produce unnecessary emotional upsets for the patient.

In most cases, however, epilepsy is a lifelong condition. A patient has to learn to live with its symptoms while trying to lead as normal a life as possible. One important step the patient can take is to wear a medical bracelet indicating that he or she is epileptic. The bracelet should also list any medications the patient is taking.

One serious complication of tonic-clonic epilepsy is called status epilepticus (pronounced STA-tuss EP-ih-LEP-tih-kuss). Status epilepticus is a condition in which attacks of tonic-clonic seizures follow each other closely. There is no recovery period between attacks when the patient returns to consciousness and normality. The patient may have trouble breathing and his or her blood pressure may rise to dangerous levels. The condition can cause death if not treated immediately. Fortunately, status epilepticus is a rare condition.

PREVENTION

Symptomatic epilepsy can be prevented if the cause of the disorder can be identified and eliminated. There is no way to prevent idiopathic epilepsy.

The risks posed by epileptic attacks, however, can be reduced. For example, people with the condition should try to get enough sleep and exercise, and eat properly. They should avoid hyperventilating (breathing rapidly and deeply), which can bring on an attack. Individuals should make sure that they take their medications regularly, according to the prescribed pattern. If they experience an aura, they should find a safe place to lie down until the attack passes.

FOR MORE INFORMATION

Books

Carson, Mary Kay. Epilepsy. Hillside, NJ: Enslow Publishers, Inc., 1998.

Landau, Elaine. Epilepsy. New York: Twenty First Century Books, 1995.

Lechtenbert, Richard. Epilepsy and the Family: A New Guide, 2nd edition. Cambridge, MA: Harvard University Press, 1999.

Sander, J., and Y. Hart. Epilepsy: Questions and Answers. Chicago: Merit Publishing International, 1997.

Shaw, Michael, ed. Everything You Need to Know about Diseases. Springhouse, PA: Springhouse Corporation, 1996.

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

Organizations

American Epilepsy Society. 638 Prospect Ave., Hartford, CT 06105–4298. (205) 232–4825.

Epilepsy Concern International Service Group. 1282 Wynnewood Dr., West Palm Beach, FL 33417. (407) 683–0044.

Epilepsy Foundation of America. 4251 Garden City Dr., Landover, MD 20875–2267. (800) 532–1000.

Epilepsy Information Service. (800) 642–0500.

Web sites

"Ask NOAH About: Epilepsy." NOAH: New York Online Access to Health. [Online] http://www.noah.cuny.edu/neuro/epilepsy.html (accessed on October 25, 1999).

Epilepsy. [Online] http://www.ninds.nih.gov/healinfo/disorder/epilepsy/epilepfs.htm (accessed February 28, 1998).

Epilepsy Facts and Figures. [Online] http://www.efa.org/what/education/FACTS.html (accessed on February 28, 1998).

Epilepsy

Definition

Epilepsy is a chronic (persistent) disorder of the nervous system. The primary symptoms of this disease are periodic or recurring seizures that are triggered by sudden episodes of abnormal electrical activity in the brain. The term "seizure" refers to any unusual body functions or activities that are under the control of the nervous system.

Description

The word epilepsy is derived from the Greek term for seizure. Seizures can involve a combination of sensations, muscle contractions, and other abnormal body functions. Seizures may appear spontaneously—without any apparent cause—or can be triggered by a specific type of stimulus such as a flashing light. Specific cases of epilepsy may result from known causes, such as brain injury, or may have no apparent cause (referred to as ideopathic epilepsy). Ideopathic epilepsy may be initiated by a combination of genetic and environmental factors.

An epileptic seizure involves a transient (temporary) episode of abnormal electrical activity in the brain. During a seizure, many nerve cells within a specific region of the brain may begin to fire at the same time. This activity may then spread out over other parts of the brain. In addition to abnormal physical symptoms, seizures can bring on emotions ranging from fear, anger, and rage, to joy or happiness. During a seizure, patients may experience disorientation, spontaneous sensations of sounds, smells, visions, and distorted visual perception—such as misshapen objects and places.

Epilepsy can be caused by some event or condition that results in damage to the brain such as strokes, tumors, abscesses, trauma (physical injury), or infections such as meningitis. Epilepsy can also be triggered by inherited (genetic) factors or some form of injury or trauma at birth. Epilepsy cases that seem to have no readily identifiable cause are referred to as "idiopathic" cases in medical terminology. Symptoms of this disease can appear at any age. Seizures can damage and destroy brain cells and scar tissue can develop in the section of brain tissue where seizures originate.

There are many forms of epileptic seizures. The parts of the body that are affected by a seizure and the distinctive characteristics, duration, and severity of the symptoms can distinguish each type of epilepsy. Patients can experience more than one type of seizure. The nature of the symptoms depends on where in the brain the seizure originated and how much of the brain is involved. Seizures can be classified as either "generalized" or "partial". Partial seizures involve abnormal activity in a specific region of the brain.

Generalized (also called tonic-clonic) seizures last about two minutes and are the result of abnormal electrical activity that spreads out over both sides or hemispheres of the brain. They were formerly referred to as grand mal seizures. The patient will usually lose consciousness and fall during the episode. The term "tonic" refers to the first phase of a generalized seizure in which the body muscles become taunt or stiff. This is followed by strong, rhythmic muscular contractions (convulsions) of the "clonic" phase. Sometimes a patient's breathing may be hampered by a brief stoppage of the respiratory muscles, causing the skin to develop a bluish tinge due to lack of oxygen.

Epileptic seizures can also be classified as "complex" or "simple." Complex seizures generally involve a loss of consciousness, whereas simple seizures do not. Simple partial seizures can begin as a localized (focal) seizure and then evolve into a "secondary generalized" episode in which the initial abnormal electrical activity spreads to involve other parts of the brain. Patients may actually remember the physical and psychological events that occur during a simple seizure, such as the types of movement, emotions, and sensations, but frequently are completely unaware of the event. Partial seizures are more common in adults.

An "absence seizure" (once called petit mal) typically results in brief periods of "lack of awareness" and some abnormal muscle movement. The patient generally remains conscious during the seizure episode, but may become absent-minded and unresponsive. They may also appear to be "starring". Absence seizures last about 5–10 seconds.

How seizures affect a person's memory depends where in the brain seizures occur. Seizures can interfere with learning, storage, and retrieval of new information. For example, a form of epilepsy that produces seizures in the temporal lobe of the brain can cause a serious deterioration (loss) of memory function. Early treatment can help prevent or reduce memory loss.

In some forms of epilepsy, seizures can be triggered by a particular mental—or cognitive—activity. For example, the simple activity of reading aloud can trigger a seizure in patients with reading epilepsy. Symptoms include face muscle spasms. In medical terms, this type of epilepsy is referred to as "idiopathic localizationrelated epilepsy". This means that seizures occur in one part of the brain (in this case, the temporal lobes) and that there is no apparent cause that brought on the disease.

Genetic profile

Genetic factors contribute to about 40% of all epilepsy cases. Most of the generalized epilepsy syndromes and some of the partial epilepsy syndromes have an inherited component. Medical researchers suggest that at least 500 genes may somehow be involved in the development of various forms of epilepsy. It is believed that some of these genes can make people with epilepsy more susceptible or sensitive to environmental factors that initiate or start seizures. Only a few types of epilepsy are thought to be caused by just one type of gene .

Gene mutations can cause a variety of nervous system abnormalities that are associated with epilepsy. Different mutations may lead to abnormal brain development or progressive degeneration of brain tissue. Some gene mutations make nerve cells "hyperexcitable." These abnormal nerve cells can trigger outbursts of abnormal patterns of electrical activity that can initiate an epileptic seizure.

Specific gene locations (called gene markers) have been linked to various forms of the disease, such as juvenile myoclonic epilepsy. However, researchers have discovered that some individuals who possess this gene do not develop symptoms of this disease. In some pairs of identical twins with this gene, one twin may appear normal while the other develops typical symptoms of epilepsy. Thus, genetic inheritance seems to be just one of many factors that influence the possibility of developing epilepsy symptoms.

Some genetic mutations may also reduce the effectiveness of antiepileptic medication. One of the major goals of epilepsy research is to determine how a patient's genetic makeup can influence their drug therapy.

Demographics

Epilepsy affects about one percent of the population. Approximately 2.3 million Americans and 40 million people throughout the world have epilepsy. It is the second-most common neurological disorder. The highest incidence is in children under 10 and elderly over 70.

Signs and symptoms

Patients have little warning that they are about to experience an epileptic seizure. Some unusual feeling or "aura" which can act as a warning that an episode is about to start generally precedes actual seizures. An "aura" may take the form of an unusual sensation such as a fearful feeling, a mental image, or an unusual taste, smell, or sound. Some patients who do not experience seizures during the day or who have prolonged "auras" or warnings of an impending seizure can be permitted to drive. Getting a good night's sleep is a common problem for young children with epilepsy. Lack of sleep can then lead to behavior problems and constant drowsiness during the daytime. A stupor may follow a seizure.

Diagnosis

Early symptoms of epilepsy include excessive staring, easy distraction, and difficulty in maintaining attention. To confirm the diagnosis, doctors look for neurological (nervous system) abnormalities such as speech or vision defects, defects in brain structure or other parts of the nervous system. The goal of the diagnositic testing is to identify where the seizures are originating. EEGs (electroencephalographs) are used to monitor electric activity—patterns of nerve impulses in the brain. A type of "brain scan" called MRI is also used extensively to try to pinpoint the location and type of abnormalities (referred to as lesions) in brain structure, which cause episodes of epileptic seizures. Idiopathic epilepsy—those cases for which no specific cause can be identified—are presumed to have a genetic basis.

Treatment and management

Currently, no cure exists for epilepsy. However, a wide range of treatment programs are available that provide varying degrees of success in controlling the symptoms of epilepsy.

Medication is the most effective and widely used treatment for the symptoms of epilepsy. Most medications work by interfering with or stopping the abnormal electrical activity in nerve cells that cause seizures. This form of treatment is generally referred to as anticonvulsant therapy. Medication is considered effective if the patient is free of seizures for at least one year.

Anticonvulsants are powerful drugs that can produce a variety of side effects, including nausea, fatigue, dizziness, and weight change. They can also increase the risk of birth defects, especially involving the early stages of embryonic development of the nervous system if taken during pregnancy.

Doctors prefer to put their patients on just one type of anticonvulsant drug. Some patients, however, experience more effective relief from their epilepsy symptoms by taking a combination of two different but "complementary" forms of medication. The choice of medication depends on the type of seizure that affects a patient, the patient's medical history—including response to other drug therapies, their age, and gender. For example, the drug Carbamazepine is one of the most effective medications and has little impact on important cognitive functions such as thinking, memory and learning.

Newer medications generally produce fewer side effects than their predecessors. Research into gene therapy may ultimately be the most effective form of epilepsy treatment, but is still in the very early stages.

Unfortunately, medication is ineffective for more than one third of known cases of epilepsy. More than 30% of patients with epilepsy cannot maintain adequate control of their seizures. Some genetic mutations may reduce the effectiveness of antiepileptic medications.

Surgery is recommended for some patients for whom medication cannot effectively control the frequency or severity of their seizures. Surgery is a treatment option only in extreme cases where doctors can identify the specific site in the brain where seizures originate. The most promising candidates for surgery are those with a single lesion on the temporal, frontal, or occipital lobes of the brain.

Prior to surgery, the patient must complete extensive testing to determine the precise patterns of seizures and to locate their point of origin in the brain. Patients spend extended stays in hospital during which their seizures are recorded on video and with the aid of EEGs. This machine records patterns of electrical activity in the brain using sensors (referred to as "electrodes") attached to various parts of the body.

The surgical procedure involves the removal of a small part of brain tissue in the "suspected" region. The anterior temporal lobe and hippocampus are the most common areas in which tissue is removed. In some studies, more than 83% of patients become free of seizures following surgery. Ninety-seven percent show significant improvement in their condition.

Vagus Nerve Stimulation (VNS) is another form of treatment for some cases of epilepsy that are unresponsive (referred to as "refractory epilepsy") to other forms of medical therapy. VNS may also be recommended for patients who cannot tolerate the side effects of medication. This procedure involves implanting a device that stimulates the Vagus nerve, located in the left side of the neck. In one study, this treatment reduced seizures by 78%.

A special dietary program is another treatment option for patients who are not good candidates for surgery or who have had little success with anticonvulsant medication. This form of treatment called the Ketogenic Diet can be effective for many types of epilepsy. It is most appropriate for young children whose parents can follow the rigid requirements of the diet. Older children and adults tend to have greater difficulty in sticking to the dietary rules for an extended period of time. The Ketogenic Diet is a stringent diet that is very high in fat, but low in proteins, carbohydrates, and calories. The excessive fat produces high levels of a substance called ketone (which the body makes when it breaks down fat for energy). Somehow these ketones help reduce the incidence of epileptic seizures. The success of this form of treatment varies. For some patients, the high fat diet is the best form of treatment. For others, the diet is less effective.

Resources

PERIODICALS

Berkovic, S.F., and I.E. Scheffer. "Genetics of the epilepsies." Current Opinion in Neurobiology 12, no. 2 (April 1999): 177–82.

Farooqui S., W. Boswell, J.M. Hemphill, and E. Pearlman. "Vagus nerve stimulation in pediatric patients with intractable epilepsy: case series and operative technique." The American Surgeon 67, no. 2 (February 2001): 119–21.

Hirose S., M. Okada, S. Kaneko, and A. Mitsudome. "Are some idiopathic epilepsies disorders of ion channels?: A working hypothesis." Epilepsy Research 41, no. 3 (Oct 2000): 191–204.

Kwan, Patrick, and Martin J. Brodie. "Early Identification of Refractory Epilepsy." The New England Journal of Medicine 342, no. 5 (February 3, 2000).

ORGANIZATIONS

American Epilepsy Society, 342 North Main Street, West Hartford, Connecticut 06117. (860) 586-7505. <http://www.aesnet.org>.

Epilepsy Foundation. 4351 Garden City Drive, Landover, Maryland 20785. (800) 332-1000. <http://www.epilepsyfoundation.org>.

Epilepsy and Brain Mapping Program: Huntington Memorial Hospital. 10 Congress Street, Suite 505, Pasadena, California 91105. (800) 621-2102. e-mail: [email protected], <http://www.epipro.com/meds.html>.

WEBSITES

"Seizures." MayoClinic.com.<http://www.mayohealth.org/home?id=SP3.1.4.7>.

"Surgical Treatment of Epilepsy." G. Rees Cosgrove, M.D., F.R.C.S.(C) and Andrew J. Cole M.D., FRCP(C). Department of Neurosurgery, Massachusetts General Hospital. 15 Parkman St., ACC Suite # 331, Boston, MA 02114. (617) 724-0357. Fax: (617) 726-5546. [email protected]. <http://neurosurgery.mgh.harvard.edu/ep-sxtre.htm>.

Marshall G. Letcher, MA