Epilepsy Facts



Causes

In about half of patients with epilepsy even our most modern scientific techniques do not permit us to decide with certainty the actual cause of the seizures. Even if there is damage to the structure of the brain, it may be so tiny we may not be able to find it. In many instances there is no apparent damage and we have to look for disturbances in how brain cells work or in the chemical reactions taking place in the brain.

The Most Common Causes Of Recurrent Seizures (Epilepsy):

  • problems arising prior to birth such as abnormal brain development, strokes, infections, or injuries.
  • problems during birth such as lack of oxygen getting to the brain. problems in the newborn including infection, very low blood glucose, or very low calcium.
  • inherited diseases or conditions such as phenylketonuria (PKU), tuberous sclerosis or neurofibromatosis
  • head injuries that damage the brain
  • tumors of the brain
  • infections of the brain such as meningitis, encephalitis and brain abscess strokes

Intractable Epilepsy

A substantial number of patients with epilepsy, perhaps 20%, have seizures that are not adequately controlled without side effects despite receiving treatment from their family doctor or neurologist. Problems may involve either lack of seizure control or intolerable side effects. These patients should be evaluated at a specialized epilepsy program. At a comprehensive epilepsy center, patients should receive a complete and thorough re-evaluation of their epilepsy by physicians who are trained epileptologists, with the help of pharmacists skilled in dispensing epilepsy medications, and special diagnostic treatment of epilepsy including video-EEG monitoring, neuropsychological evaluations and counseling by psychologists.


Common Seizure Types

Seizures are divided into two main groups: generalized and partial. Generalized seizures are said to involve the entire brain almost instantaneously. Some common generalized seizure types are simple absence attacks, myoclonic, tonic, atonic, and primary idiopathic generalized tonic-clonic seizures. By far the most common kind of seizures begin in one part of the brain and are classified as partial. These partial seizures may be simple or complex depending upon whether they involve a disturbance of consciousness.

Generalized Seizures
Absence (these seizures were called petit mal in the past): Absence seizures ordinarily occur in young children between the ages of four and ten, but may persist into adulthood. There is a brief loss of awareness, lasting usually from one to ten seconds. The patient stops, may stare, and there may be some eye blinking or mild facial twitching or mouth movements. There is no warning and consciousness is restored instantly. The patient is unaware of these seizures, and because they may occur 60 to 100 times a day, may be accused of being inattentive.

A child who is experiencing many of these seizures a day is unable to pay attention in school and may fail to learn. Since the patient doesn't fall and the signs are subtle, these seizures are often not diagnosed for a long time. Although many children with absence seizures will "outgrow" them about the time they go through puberty, they may persist beyond childhood. Absence seizures are frequently associated with generalized tonic-clonic seizures, which often persist into adulthood.

Myoclonic, Atonic and Tonic seizures are relatively rare, but frequently very disabling. They are brief twitches or sudden falls because of abrupt increased or decreased muscle tone in the body. They may be very hard to treat. Usually there is not a prolonged disturbance of consciousness with these seizures.

Generalized Tonic-Clonic (old term grand mal): The patient suddenly gets stiff in all limbs and loses consciousness, and falls to the floor. A period of rhythmic jerking of the limbs, the so-called clonic phase, follows. The person may cry out, not from pain but from air forced out of the body by contractions of the chest muscles.

The patient's tongue or cheek may be bitten if it is caught between the teeth. Sometimes there is loss of bladder or bowel control. The patient does not breathe normally or may stop breathing during the seizure (which usually lasts less than a minute). When breathing returns it is usually labored and there is a lot of saliva. The patient usually regains consciousness slowly, and may be confused, sleepy, and often has a headache.

In primary generalized seizure there is no aura (for example, an odd smell, a feeling of a breeze on the skin, other strange feeling) or weakness of one side of the body or speech difficulty before it begins. If any of these symptoms occur first, they are a sign that the generalized tonic-clonic seizure started in one part of the brain and then spread. This is called a secondarily generalized seizure. Patients with these symptoms may require a different kind of treatment.

Partial Seizures
Complex Partial Seizures (old term temporal lobe or psychomotor): These seizures may be very brief or last several minutes. They are the most variable of all the seizures. There is a disturbance, but not complete loss of consciousness or a complete loss of tone. The person does not fall. He or she may look puzzled or confused, there may be chewing movements, senseless speech, wandering about aimlessly or picking at clothing. Seizures of this type are often preceded by an aura, which is actually the beginning of the seizure.

People may experience extremes of emotion (fear or pleasure), disturbances in thinking, or appear to be mentally deranged. When wandering unaware during seizures, they may struggle to get free if they are restrained, but do not usually display any kind of directed violence.

Simple Partial Seizures (focal motor, focal sensory or Jacksonian): People with this type of seizure remain fully conscious and aware throughout. What they experience is a sudden sensation or uncontrollable movement of a single part of the body, or movement that progresses along the body from hand to arm to face, eventually to involve one entire side of the body.

Secondarily Generalized Seizures: Either simple or complex partial seizures may secondarily generalize (spread) to involve the whole brain and become generalized tonic-clonic seizures.


Treatment of Seizures

The proper treatment of seizures requires an early, precise diagnosis, a careful choice of medicines, and attention to the psychological and social issues, which inevitably accompany chronic health problems. Once a precise diagnosis of the type of seizures has been made, the first course of treatment is to use antiepileptic drugs chosen to match the type of seizure. Details of the medicines currently approved by the Food and Drug Administration and their indications and side effects can be found in the antiepileptic medication chart.

The aim of treatment with antiepileptic medicines is the complete control of seizures without side effects. Although all medicines carry risks, most antiepileptic medications are generally safe. Be sure you are familiar with the side effects and other problems that are associated with the medications that are prescribed for you and report them immediately to your physician.

The dose of medicine prescribed is based on individual differences in how your body uses up each dose, how much you weigh, how quickly the drug is absorbed and eliminated, and possible interactions with other medicines being taken for epilepsy or other disorders.

The ketogenic diet, a strict, doctor prescribed diet very high in fat and very low in carbohydrates, is occasionally useful, especially for children with Lennox-Gastaut syndrome between the ages of two and five. Be sure to discuss this in detail with your physician.


Inheritance & Epilepsy

Everybody inherits a unique degree of susceptibility to seizures. 9% of people have a seizure at some time in their life. Some people are so resistant to seizures that they never have one. Others have a genetic makeup that makes it very easy to have seizures. If there is no family history of epilepsy, about 3% of the population will have more than one seizure in their lives. However, fewer than 1% will require treatment for any long period of time. If one parent has epilepsy, the risk to the children is doubled to about 6%. If both parents or one parent and a brother or sister have epilepsy, the risk is about 10%.

Genetics plays an important role in so called idiopathic epilepsy (meaning epilepsy of unknown cause) such as absence seizures and simple generalized tonic-clonic seizures. Genetics plays a secondary role in the development of complex partial seizures later in life. In this case, the frequency of the seizures, rather than the likelihood of developing epilepsy, is most heavily influenced by heredity. A genetic counselor is very helpful in giving guidance about the inheritability in a given family.


Diagnosis & Treatment

Most cases of epilepsy in the United States are treated by family practitioners, yet family practitioners will see a new case of epilepsy on the average of only once every two years. For this reason patients are often referred to a neurologist, or even better, to a specialized epilepsy center, for definitive treatment.

The diagnosis of epilepsy is based largely on medical history. An EEG is very helpful, but unless the physician actually witnesses the seizures while an EEG is running, the diagnosis could always be in doubt. Ordinarily an evaluation for epilepsy should include a careful history of the patient and his or her family to see if other members of the family have had seizures and what kind; whether there have been other neurological problems or other illness that can cause epilepsy; and a review to see whether any other medicines are being taken.

  • A careful description of the seizure is most important. Specific areas of the brain control different bodily functions; a detailed description of the seizure helps to determine what parts of the brain are involved.
  • A general physical and neurological examination to look for causes should include testing of specific functions of the central nervous system.
  • Blood tests are used to check for such things as infections, disturbances in blood cells, problems in the liver, etc.
  • Electroencephalogram (EEG): By measuring the electrical changes that occur normally in the brain, the physician can look for any abnormal discharges or distinctive brainwave patterns that help make the diagnosis.
  • Magnetic Resonance Imaging (MRI): Similar to x-ray examinations, but using strong magnetic fields, an MRI is a computer-generated picture of the brain. The pictures are much more detailed than those revealed by X-rays, including CT (computerized tomography) scans.
  • Video EEG Monitoring (sometimes inaccurately called telemetry): In specialized epilepsy centers the patient can have an EEG and a video picture recorded simultaneously, which enables a physician to make the definite diagnosis.
  • Other special imaging studies, such as PET and SPECT, may be carried out.
  • If the patient is thought to be getting too much medicine, or might have extensive brain damage, or if brain surgery is being considered, tests to evaluate various aspects of brain function. Neuropsychological tests may also be performed

Surgical Intervention

Surgery is highly effective in controlling seizures in appropriate cases. Patients who have repeated attacks of identical-looking seizures that arise from one part of the brain, or who have drop attacks, may be particularly good candidates. In order to find out if surgery is an option for treating an individual patient, a careful and thorough pre-surgical evaluation must be performed. This should be done at a comprehensive epilepsy program with extensive experience in the surgical treatment of epilepsy--one that performs these procedures regularly and frequently. The National Association of Epilepsy Centers recommends that a center perform at least 25 surgeries a year, on the average, to have adequate experience.

There are always risks with any treatment and especially with surgery. Only patients who cannot be controlled adequately and comfortably on antiepileptic medicine should be considered for surgery. Patients and their physicians must consider all factors before deciding on surgery. On the other hand, surgery should not be unduly delayed. It works very well and is very safe for many people.

The most common type of surgery performed for the treatment of epilepsy is the anterior temporal lobectomy. This removes the front part of the temporal lobe (there are two temporal lobes, one on each side of the brain, just above the ears). The reason it is the most common surgery performed is that most patients with epilepsy have complex partial seizures, and most cases of complex partial seizures are caused by a problem in the mesial (middle) and anterior (front) portion of the temporal lobe. In order to have the surgery, the evaluation must show that all the seizures are arising from this part of the brain. It is also important to be sure that the surgery will not cause speech defects or other serious neurological problems.

A second type of surgery, cutting the corpus callosum (a bridge of fibers connecting one side of the brain to the other), is now less frequently performed because of improved antiepileptic drugs and the development of the vagal nerve stimulator. This operation is used to treat patients who have drop attacks, either tonic or atonic. These seizures cause violent falls and often serious injury. The aim here is not so much complete control of the seizures, since the same patient often has other types of seizures as well, but a reduction in the frequency and severity of the falls and hopefully a reduction in generalized tonic-clonic seizures also.

If a person's seizures come from the cortex of the brain in the frontal or parietal area, or from certain parts of the temporal lobe, it may be possible to remove a part of the cortex safely without causing speech or motor problems. It is often necessary to place a group of electrodes (called an array) on the surface of the brain. By recording and stimulating various areas, the surgeons map which part of the brain should be removed and which parts cannot be touched.

Children who have very severe seizures coming from one side of the brain, and who already have paralysis of one side of the body, may benefit from a hemispherectomy, removal of all or most of one side of the brain. Surgery often results in complete control of seizures, a marked improvement in alertness, and an improvement in ability to learn.


Following the Treatment Plan

It is important to take antiepileptic medications regularly. In order for the medications to work, there must be a steady and effective amount of medicine in the blood stream and the brain. The proper blood level cannot be maintained unless medications are taken as prescribed, and the prescription must take into account the half-life of the medicine and the metabolism of the individual. Most people have a hard time remembering to take all of their medications at the proper time. The use of a pillbox and even an alarm watch is very helpful. Missed doses result in an inadequate level of medicine in the body and may permit seizures to occur.

Some people are so afraid of becoming dependent on their medicines that they don't take their pills. Still others hope that since they haven't had a seizure for a while they no longer need to take medicine. While some people can safely stop taking medicines after a few years, most people need to take it for their entire lifetime. Stopping medicines to see if you can get along without them should only be done under close medical supervision. Dependency on antiepileptic medicine is similar to having to take insulin for diabetes and should not be compared to the problems of addiction to illegal drugs.


 
 

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