Epilepsy is a chronic, non-contagious brain disorder characterized by recurring seizures - brief electrochemical disturbances in the brain that upset the brain's normal control of the body. This disorder affects more than 2.5 million Americans, and 125,000 new cases develop each year.
What is a seizure? Who gets epilepsy, and what causes it? How is epilepsy diagnosed? What are the treatments? How can I help if someone has a seizure?
What Is a Seizure?
Normal brain function is made possible by millions of tiny electrical charges passing between nerve cells in the brain and all over the body. A seizure is the disturbance of the brain's normal electrical activity, causing a temporary change in behavior, consciousness, bodily movements or sensation.
Many illnesses or severe injuries can cause a single seizure, but that doesn't mean a person has epilepsy. People with epilepsy have seizures that continue to happen for unknown reasons or because of an underlying problem that can't be treated. Epilepsy can also occur in animals, including dogs, cats, rabbits and mice.
There are a variety of different kinds of seizures. Generalized seizures involve the entire brain, while partial seizures occur in just one part of the brain. Some people with epilepsy may experience many different kinds of seizures, while others may only have one type of seizure.
Four common types of generalized and partial seizures:
- Tonic-clonic seizures: These seizures, previously known as grand mal seizures, are generalized seizures. Sometimes a person with this type of epilepsy will experience an "aura," or warning, just before the seizure begins. During tonic-clonic seizures, a person stiffens and falls to the ground unconscious - this is called the tonic phase. The clonic phase begins with strong, rhythmic shaking movements. Drooling and loss of bladder or bowel control may occur. The seizure normally stops after a minute or two. After waking up, the person is often confused and drowsy. The drowsiness may last a few hours.
- Absence seizures: These seizures, also called petit mal, are more common in children and are sometimes mistaken for daydreaming. Like tonic-clonic seizures, they are generalized, but are much milder. People experiencing this type of seizure lose awareness of what is happening around them, but they rarely fall to the ground. Their eyes may roll back, they may stare, or their eyelids may flutter. Absence seizures start suddenly, last a few seconds, then stop suddenly, and the person simply continues whatever he or she was doing before the seizure. Although these seizures are very brief, they may occur many times each day.
- Simple partial seizures: These seizures involve only one part of the brain, so symptoms will vary depending on which part of the brain is involved. Unlike tonic-clonic and absence seizures, people experiencing simple partial seizures remain fully conscious. Common symptoms of these seizures include stiffness or shaking in one part of the body or an abnormal feeling, such as numbness or an unpleasant smell or taste. Simple partial seizures usually last for less than a minute.
- Complex partial seizures: These are the most common type of seizure. They involve only one part of the brain, but the person's conscious state is altered. He or she may appear confused and do unusual things like make sounds, fiddle with clothing or make chewing movements. Complex partial seizures only last for one to two minutes, but the person may be confused and drowsy for a long period of time afterwards.
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Who gets epilepsy, and what causes it?
Epilepsy is not a single syndrome characterized by a short list of symptoms and a few causes - it's a broad range of brain disorders that involve seizures. For this reason, it's hard to determine the cause of epilepsy. About 30 percent of people with epilepsy have their first seizure as a young child or adolescent, but epilepsy can develop at any age. Some forms are genetically related, but most types are not. A few people have epilepsy for a short period of their lives, and the disorder disappears on its own.
Here are some of the known causes of epilepsy and/or seizures:
- Diseases like meningitis or encephalitis
- Congenital disease
- Birth or pre-birth trauma
- Brain injuries or scar tissue from brain operations
- Abnormal metabolism, chemical imbalance or allergies
- Brain tumors or degenerative brain diseases
- Vascular disorders or stroke
In seven out of ten cases, however, epilepsy's cause is unknown.
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How is Epilepsy Diagnosed?
If you think you or a loved one might be having seizures, it's important to keep a careful record of what has been happening and see your doctor immediately. This record will help your doctor as he or she makes a diagnosis. An electroencephalograph (EEG), a diagnostic machine that records brain waves through tiny wires attached to your scalp, may be used to provide your doctor with more information. Imaging methods, like CT (computerized tomography) or MRI (magnetic resonance imaging) may be used to look for physical causes of the seizures. Positron emission tomography (PET), which maps regional cerebral blood flow and metabolic activity, may also be used.
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What Are the Treatments for Epilepsy?
There is no "cure" for epilepsy - the goal of treatment is to control seizures. People with epilepsy should get enough sleep, avoid unusual stress and work closely with their doctors for therapy to be most effective. There are several different ways to treat epilepsy, including:
Drug therapy: Drug therapy is by far the most common treatment and is usually the first to be tried. At least three-quarters of people with epilepsy find that their seizures are reduced or completely controlled with drugs called anti-epileptic drugs (AEDs). There are a wide variety of AEDs available, each designed to control different types of seizures - so people with more than one type of seizure may take more than one type of drug.
AEDs won't work properly until they reach a certain level in the bloodstream, and that level must be carefully maintained. It's important that people with epilepsy follow their doctor's instructions very carefully as to when and how their medicine should be taken.
Unfortunately, AEDs can cause unpleasant side effects, like drowsiness, irritability, tremors, double vision and nausea. Sometimes, doctors must adjust medication levels several times to control seizures while minimizing side effects.
Diet: A special diet called the ketogenic diet may be used to treat epilepsy, especially in children. This diet is designed to produce a chemical condition in the body called ketosis, which can prevent seizures.
It is usually tried when drug therapy is unsuccessful. Some children are helped dramatically by the diet, but it doesn't work for everyone.
The ketogenic diet is very high in fats and low in carbohydrates. It can be followed by changing the kinds of foods that are eaten and by adding a special kind of oil to a standard diet. For the ketogenic diet to work, it must be followed very strictly - the whole family must be strongly committed to it.
Surgery: Epilepsy that doesn't respond to drug treatment is said to be medically refractory. After a period of two to five years where doctors and a patient have tried many different drug therapies without controlling seizures, epilepsy surgery may be an option. About 500 epilepsy surgeries are performed in the United States each year, and surgical techniques are improving rapidly.
When considering surgical therapy, doctors and patients must first consider seizure frequency, severity and effect on quality of life. Sometimes, chronic use of some types of anti-epileptic drugs will produce toxic syndromes. Also, repeated seizures may cause progressive brain damage and severe handicaps. All of these are important factors that may influence the decision of whether to have surgery.
First, doctors will carefully map the brain to find out where the medically refractory seizures originate. These are called "hot spots" or epileptic foci. Then, they will consider whether removing the epileptic foci will cause irreparable damage to brain areas important for cognitive or sensory functions. If doctors determine that the epileptic foci can be safely removed, neurosurgeons remove them, which can improve the overall function of the brain and reduce or eliminate seizures.
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How can I help if someone has a seizure?
You can't stop a seizure from happening - but you can help a person experiencing a seizure make a quick and safe recovery. The most important points are:
- Remain with the person
- Stay as calm as possible
First aid for tonic-clonic seizures:
- Remove eyeglasses and loosen tight clothing
- If possible, move hard or sharp objects out of the person's way
- Support the head with a cushion or pillow
- Do not attempt to restrain the person or stop them from jerking
- Do not put ANYTHING in the person's mouth
- If you have help, roll the person onto his side during the seizure - if not, wait until after the seizure is over to do this
- Stay with the person until he has fully recovered
- Explain what has happened and reassure him
- Do not offer anything to eat or drink until he or she is completely awake
- If a tonic-clonic seizure lasts more than 10 minutes, call an ambulance immediately
First aid for absence seizures:
- Recognize that the seizure has occurred
- Reassure the person and repeat any information he or she may have missed during the seizure
First aid for simple partial seizures:
- Make sure the person is in no danger of getting hurt
First aid for complex partial seizures:
- If necessary, guide the person gently to safety
- Do not try to restrain him during the seizure
- Stay with the person until he is fully recovered
- Explain what has happened and reassure him
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