Seizure Disorder / Epilepsy
Epilepsy is a disorder that disrupts the transmission of electrical signals inside the brain. Although you may assume that epilepsy always causes episodes of uncontrolled movements and loss of consciousness, the condition is actually quite variable. Symptom episodes — known as seizures — are often subtle, causing strange sensations, emotions and behavior. Some people with epilepsy simply stare blankly for a few seconds when having a seizure, while others have full-fledged convulsions.
About one in 100 people in the United States has experienced an unprovoked seizure at some point in life. However, a solitary seizure doesn't mean you have epilepsy. Many people — for example, children with high fevers — experience one seizure and then never have another one. But after you've had two seizures, the chance that you'll have additional seizures increases dramatically. At least two unprovoked seizures are required for a diagnosis of epilepsy.
The onset of epilepsy is most common during childhood and after age 65, but the condition can occur at any age. Treatments may leave you free of seizures, or at least reduce their frequency and intensity. Many children with epilepsy even outgrow the condition with age.
Several types of epilepsy have been linked to defective genes that regulate how brain cells communicate with each other, but only a few rare types of the disorder are known to arise from specific gene defects. Otherwise, it appears that abnormalities in any of several hundred genes may play a role in the development of epilepsy. Although some forms of epilepsy tend to run in families, genetic inheritance plays only a partial role in causing epilepsy — perhaps by making a person more susceptible to environmental factors that cause seizures.
In many cases, the onset of epilepsy can be traced to an accident, disease or medical trauma — such as a stroke — that injures your brain or deprives it of oxygen. In rare instances, epilepsy may be caused by a tumor in your brain. However, epilepsy has no identifiable cause in about half of all affected people.
Risk Factor :
If you have a family history of epilepsy, you may be at increased risk of developing a seizure disorder.
Head injuries are responsible for many cases of epilepsy. You can reduce your risk by always wearing a seat belt while riding in a car and by wearing a helmet while bicycling, skiing, riding a motorcycle, or engaging in other activities with a high risk of head injury.
Stroke and other vascular diseases can lead to brain damage that may trigger epilepsy. You can take a number of steps to reduce your risk of these diseases, including limiting your intake of alcohol, following a healthy diet, managing your weight, exercising regularly and avoiding cigarettes.
Other epilepsy risk factors include brain infections, such as meningitis, and prolonged seizures in childhood due to high fevers.
When to seek medical advice :
Having a known diagnosis of epilepsy may not mean you need to seek medical help each time you have a seizure, as long as you and your family members are well versed in what to do when a seizure occurs. Seek medical advice if you experience a seizure for the first time. Also, seek medical help if any of the following occur :
- The seizure lasts more than five minutes.
- Recovery from your seizure is slow.
- A second seizure follows immediately.
- You're pregnant or have diabetes.
- Your seizures change in frequency and severity.
- There's a change in the way you feel during and after the seizures.
- Your seizure is preceded by a sudden, severe headache or other symptoms or signs of stroke — including weakness or numbness on one side of your body, vision loss, confusion, and coordination or speech problems.
If you see someone having a seizure, call for medical help immediately and then follow these tips :
- Gently roll the person onto one side and put something soft under his or her head. Loosen tight neckwear.
- Don't try to put your fingers or anything else in the person's mouth. No one has ever "swallowed" his or her tongue during a seizure — it's physically impossible.
- Don't try to restrain someone having a seizure, and don't attempt to rouse the person by shouting at or shaking him or her. If the person is moving, clear away dangerous objects.
- Look for a medical alert bracelet. The bracelet should state who to contact in an emergency and what medications the person uses.
- Stay with the person until medical personnel arrive. If possible, observe the person closely so that you can provide details on what happened.
Because epilepsy is caused by abnormal activity in brain cells, seizures can affect any process your brain coordinates. A seizure can produce temporary confusion, complete loss of consciousness, a staring spell, or uncontrollable jerking movements of the arms and legs.
Symptoms vary depending on the type of seizure. In most cases, a person with epilepsy will tend to have the same type of seizure each time, so the symptoms will be very similar from episode to episode. But some people have many different types of seizures, with different symptoms each time.
Doctors classify seizures as either partial or generalized, based on how the abnormal brain activity begins. When seizures appear to result from abnormal activity in just one part of the brain, they're called partial or focal seizures. Seizures that seem to involve all of the brain are called generalized seizures. In some cases, seizures can begin in one part of the brain and then spread throughout the rest of the brain.
- Simple partial seizures. These seizures don't result in loss of consciousness. They may alter emotions or change the way things look, smell, feel, taste or sound.
- Complex partial seizures. These seizures alter consciousness, causing you to lose awareness for a period of time. Complex partial seizures often result in staring and nonpurposeful movements — such as hand rubbing, lip smacking, arm positioning, vocalization or swallowing.
- Absence seizures (petit mal). These seizures are characterized by staring, subtle body movement and brief lapses of awareness.
- Myoclonic seizures. These seizures usually appear as sudden jerks of your arms and legs.
- Atonic seizures. Also known as drop attacks, these seizures cause you to suddenly collapse or fall down.
- Tonic-clonic seizures (grand mal). The most intense of all types of seizures, these are characterized by a loss of consciousness, body stiffening and shaking, and sometimes tongue biting or loss of bladder control.
Your doctor will need a detailed description of your seizures. Because many people with epilepsy don't remember what happens during their seizures, your doctor may need to talk to someone who has witnessed your seizures.
During the office visit, your doctor may perform a neurological exam that tests your reflexes, muscle tone, muscle strength, sensory function, gait, posture, coordination and balance. Your doctor may also ask questions to test your thinking, judgment and memory.
Blood tests may be needed to check for problems — such as infections, lead poisoning, anemia or diabetes — that could be causing or triggering your seizures.
Your doctor may also suggest scans or tests designed to detect abnormalities within the brain.
An EEG records the electrical activity of your brain via electrodes affixed to your scalp. People with epilepsy often have changes in their normal pattern of brain waves, even when they're not having a seizure.
To prepare for an EEG, avoid elaborate hair styling, metallic hair spray or greasy hair dressing. Refrain from caffeine for six hours before the test. The procedure itself is painless and usually lasts about 30 minutes. However, it can take as long as an hour to place the electrodes on your scalp.
In some cases, your doctor may recommend video-EEG monitoring. This can be helpful because it allows your doctor to compare — second by second — the behaviors that occur during a seizure with your EEG pattern from exactly that same time. This helps your doctor pinpoint exactly where your seizures originate, which aids treatment decisions.
Video EEGs are expensive because you usually must stay at the testing facility for several days. The EEG electrodes stay attached for that entire time, and you are videotaped continuously.
Computerized tomography (CT)
Using special X-ray equipment, CT machines obtain images from many different angles and join them together to show cross-sectional images of your brain and skull. CT scans can reveal abnormalities in brain structure, including tumors, cysts, strokes or tangled blood vessels. This helps your doctor rule out other potential causes of your seizures.
To prepare for a CT scan of your head, you should remove such things as earrings, eyeglasses, dentures and hairpins. You may need to have an intravenous (IV) line inserted if your test requires the injection of a contrast material — which makes abnormalities easier to see. During the test, you will lie on a table that slides into the CT machine. Depending on the number of images needed, the scan can take between two and 20 minutes. The procedure is painless.
Magnetic resonance imaging (MRI)
An MRI machine uses radio waves and a strong magnetic field to produce detailed images of your brain. Like CT scans, MRIs can reveal brain abnormalities that could be causing your seizures. Dental fillings and braces may distort the images, so be sure to tell the technician about them before the test begins.
During the test, you will lie on a padded table that slides into the MRI machine. Your head will be immobilized in a brace, to improve precision. The test is painless, but some people experience an uncomfortable feeling similar to claustrophobia inside the MRI machine's close quarters. If you think you may have a problem like this, your doctor can prescribe anti-anxiety medications beforehand.
A special type of MRI — called functional MRI (fMRI) — can measure the small metabolic changes that occur when a part of your brain is working. An fMRI can record which areas of your brain are working when you perform certain tasks, such as rubbing a block of sandpaper or answering simple questions.
Doctors know the general areas of the brain responsible for such tasks as thought, speech, movement and sensation, but the precise locations vary by individual. An fMRI can identify the locations of these critical functions so that your doctor can determine if epilepsy surgery would be a safe option for you.
Positron emission tomography (PET)
PET scans use injected radioactive material to help visualize active areas of the brain. The radioactive material is tagged in a way that makes it attracted to glucose. Because the brain uses glucose for energy, the parts that are working harder will be brighter on a PET image.
After the radioactive material is injected, it will take between 30 and 90 minutes for the substance to accumulate in your brain tissue. During this waiting period, you will be asked to rest quietly and not talk or move around much. The actual scan takes 30 to 45 minutes. The amount of radioactive material used in the test is very small, and its glucose-binding activity in the brain lasts only a short period of time.
Single-photon emission computerized tomography (SPECT)
This type of test is used primarily in people being evaluated for epilepsy surgery when the area of seizure onset is unclear on MRIs or EEGs. SPECT imaging requires two scans — one during a seizure and one 24 hours later. Radioactive material is injected for both scans and then the two results are compared. The area of the brain with the greatest activity during the seizure can be superimposed onto the person's MRI, to show surgeons exactly what portion of the brain should be removed.
If you fall during a seizure, you may sustain a head injury. Drowning is a very real risk if you have a seizure while swimming or bathing.
A seizure that causes either loss of awareness or control can be dangerous if you're driving a car or operating other equipment. Drugs used to control seizures also can cause drowsiness, which may affect your driving ability. Many states have licensing restrictions related to your ability to control seizures.
Seizures during pregnancy pose dangers to both mother and baby, and certain anti-epileptic medications increase the risk of birth defects. If you have epilepsy and you're considering becoming pregnant, talk to your doctor. Most women with epilepsy can become pregnant and have a healthy baby, but many need to adjust their medications and be carefully monitored throughout pregnancy. It is very important to work with your doctor and to plan your pregnancy.
Life-threatening complications from epilepsy are uncommon, but do occur. People who have severe, prolonged or continuous seizures (status epilepticus) are at increased risk of permanent brain damage and death. People with epilepsy, particularly people with poorly controlled epilepsy, also have a small risk of a condition called sudden unexplained death in epilepsy (SUDEP). Your risk of SUDEP increases if you:
- Began having seizures at an early age
- Have frequent seizures that involve more than one area of your brain
- Continue to have seizures despite medication
Most people with epilepsy can become seizure-free by using a single anti-epileptic drug. Others can decrease the frequency and intensity of their seizures with medication. More than half the children with medication-controlled epilepsy can eventually stop medications and live a seizure-free life. Many adults also can discontinue medication after two or more years without seizures.
Finding the right medication and dosage can be complex.
your seizures originate in a small, well-defined area in the temporal lobes or the frontal lobes of your brain. Surgery is rarely an option if you have seizures that start in several areas of the brain or if you have seizures originating from a region of the brain that contains vital brain functions.
During the procedure, your surgeon makes an incision in your scalp and removes a piece of the skull bone. He or she then cuts into or removes the area of the brain that's causing the seizures.
Although many people continue to need some medication to help prevent seizures after surgery, you may be able to take fewer drugs and reduce your dosages. In some cases, surgery for epilepsy can cause complications such as permanently altering your cognitive abilities. Talk to your surgeon about his or her experience, success rates and complication rates with the procedure you're considering.
Vagus nerve stimulation
A device called a vagus nerve stimulator is implanted into your chest under the collarbone. Wires from the stimulator are wrapped around the vagus nerve in your neck. The vagus nerve connects your brain to your heart, lungs and gastrointestinal tract. The device turns on and off according to an adjustable program. It's not clear how brain stimulation via the vagus nerve inhibits seizures, but the device reduces seizures by about 20 percent to 40 percent on average. Most people still need to take anti-epileptic medication, but many can reduce their dosage.
Some children with epilepsy have been helped by adopting a rigid diet that's high in fat and protein and low in carbohydrates. The goal of the diet is to get the body to produce ketones, which cause the body to use fat instead of glucose for energy. The exact way in which the ketogenic diet works is unclear.