What are the risk factors?

Risk factors for epilepsy include:

• Babies who are small for their gestational age
• Babies who have seizures in the first month of life
• Babies who are born with abnormal brain structures
• Bleeding into the brain
• Abnormal blood vessels in the brain
• Serious brain injury or lack of oxygen to the brain
• Brain tumors
• Infections of the brain: abscess, meningitis, MeningitisA bacterial infection of the membranes surrounding the brain; often diagnosed by a spinal tap (lumbar puncture).Close or encephalitis
• Stroke resulting from blockage of arteries
• Cerebral palsy
• Mental handicap
• Seizures occurring within days after head injury ("early posttraumatic seizures")
• Family history of epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closeor fever-related seizures
• Alzheimer's disease (late in the illness)
• Fever-related (febrile) seizures that are unusually long
• Use of illegal drugs such as cocaine

Mild head injuries, such as a concussion with just a very brief loss of consciousness, ConsciousnessState of awareness; if consciousness is preserved during a seizure, the person can respond (either in words or actions, such as raising a hand on command) and recall what occured during the spell.Close do not cause epilepsy.00

I don't think any of those risk factors apply to me! Although the disorders and injuries on these lists help to explain many cases of epilepsy, more people with epilepsy don't have any of these factors apparent in their medical history. Medical historyThe account of a patient's disorder.Close Often we just don't know how epilepsy gets started. Even though you may not know the cause of your epilepsy, you can help yourself by looking for factors (often called "triggers") that seem to make your seizures more frequent or more severe and then avoid them altogether or atleast reduce their effects.

Missed medication Lack of sleep Illness (both with and without fever) Severe psychological stress Heavy alcohol use Use of cocaine and other recreational drugs such as Ecstasy Over-the-counter or prescription medications or supplements that decrease the effectiveness of seizure SeizureA sudden, excessive discharge of nervous-system electrical activity that usually causes a change in behavior.Closemedicines Nutritional deficiencies: vitamins and minerals The menstrual cycle

Is epilepsy inherited?

It may seem obvious that heredity (genetics) plays an important role in many cases of epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closein very young children, but it can be a factor for people of any age. For instance, not everyone who has a serious head injury (a clear cause of seizures) will develop epilepsy. Those who do develop epilepsy are more likely to have a history of seizures in their family. This family history suggests that it is easier for them to develop epilepsy than for others with no genetic predisposition.

Epilepsy in which the seizures begin from both sides of the brain at the same time is called primary generalized epilepsy. Primary generalized epilepsy is more likely to involve genetic factors than partial epilepsy, in which the seizures arise from a limited area of the brain.

Are the brothers and sisters of children with epilepsy more likely to develop it?
Their risk is slightly higher than usual, not because they will "catch" it (that can't happen) but because there may be a genetic tendency in the family that makes seizures and epilepsy more likely. Even so, most of them will not develop epilepsy. Epilepsy is more likely to occur in a brother or sister if the child with epilepsy has primary generalized seizures. Depending on the type of epilepsy and the number of family members who are affected, only about 4% to 10% of the other children in the family will have epilepsy.

If I have epilepsy, will my children also have it?
Less than 2 people out of every 100 (2%) develop epilepsy at some point during their lifetime. The risk for children whose father has epilepsy is only slightly higher. If the mother has epilepsy and the father does not, the risk is still less than 5%. If both parents have epilepsy, the risk is a bit higher. Most children will not inherit epilepsy from a parent, but the chance of inheriting epilepsy is higher for some types.

If you have epilepsy, it is normal for you to be afraid that your children will have epilepsy too. However, a fear that your children will have epilepsy is not enough reason to decide against having any. The risk is low, most children outgrow epilepsy, and most people who have it are able to control their seizures by taking one medicine.

Will I always have epilepsy?

About 80% of people with epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closetreated with seizure SeizureA sudden, excessive discharge of nervous-system electrical activity that usually causes a change in behavior.Closemedicines remain free of seizures for at least 2 years. Many never have any more seizures. The chances of becoming completely seizure-free are best if there is no known brain injury or abnormality, and if the person has a normal neurological examination and EEG.

Of adults, 50-60% will be seizure-free after using their first seizure medicine. Another 11-20% will gain seizure control using the second medication, leaving 20-30% who are still having seizures.

Among those who are young when their epilepsy is diagnosed, 20% start on medication and never have another seizure after medication is stopped, even when they reach adulthood. About 50-60% of children become seizure-free with the first medication used, but 30% never stop taking seizure medicines. About 10% have a really difficult time with “intractable IntractableDifficult to alleviate, remedy, or cure; for example, intractable seizures are difficult to control with the usual antiepileptic drug therapy.Closeseizures.”

The more time that passes without seizures, the greater is the chance of staying seizure-free. Over 50% of children outgrow their epilepsy. Twenty years after the diagnosis, three-quarters of people will have been seizure-free for at least 5 years, although some may still need to take daily medication.

Will I have to take seizure medicines for the rest of my life?
Many people who are seizure-free for 2 to 4 years can stop taking their medications, under their doctor's supervision, without having further seizures. However, about 30% of children and 30% to 65% of adults will have seizures again. You need to discuss this with your neurologist and, if the decision is made to go off medication, agree on a plan for stopping gradually over weeks or months, not all at once. Currently, most neurologists in the United States and Canada consider withdrawing seizure medicines after someone has been seizure-free for 1 to 2 years.

Whether it will be safe for you to stop taking your seizure medicine depends partly on whether you drive a car or engage in other activities that would be dangerous if you had another seizure. If your answer is "yes," you will need to be more cautious.

I've been taking seizure medicine but I'm still having seizures. Will I always have them?
Some people with seizures that cannot be controlled with tolerable doses of seizure medicine (who have what doctors call "intractable epilepsy") do eventually become seizure-free. The longer that you continue to have seizures after the diagnosis of epilepsy is made, however, the lower the chance that your seizures will stop.

Your doctor will want you to try different medications or combinations of them. The more medicines that are unable to control your seizures, however, the less likely it is that another medication regimen will fully succeed. Other kinds of treatments, such as vagus nerve stimulation or epilepsy surgery, may be very helpful for some people who continue to have seizures while taking seizure medicines.

Medical History

Telling what happened
The medical history Medical historyThe account of a patient's disorder.Closeis the foundation of the diagnosis of epilepsy. EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Close The doctor needs ALL the information about what happened before, during, and after your seizures. If you cannot give enough information, then others who have seen the seizures happen should contribute what they know. If some of the details are vague, the doctor needs to know that too.

What will the doctor ask?
To get a full picture of what the spell SpellA period, bout, or episode of illness or indisposition; refers to seizures or other disorders that produce brief episodes of behavioral change.Closewas like and what might have caused it, the doctor probably will ask about things that happened before and after it as well as during the incident itself.

Before the spell:

• Did you experience lack of sleep or unusual stress?
• Were you sick recently?
• Did you take any kind of medication, including over-the-counter medicines, alcohol, or illegal drugs?
• What were you doing immediately before the event (for instance, lying down, sitting, standing, getting up from a lying position, heavy exercise)?

During the spell:

• What time of day was it?
• Were you just waking up or falling asleep?
• How did it begin?
• Was there a warning?
• Did your eyes, mouth, face, head, arms, or legs move abnormally?
• Were you able to talk and respond appropriately?
• Did you lose control of your bladder or bowels?
• Did you bite your tongue or the inside of your cheeks?

After the spell:

• Were you confused or tired?
• Could you speak normally?
• Did you have a headache?
• Did your muscles ache?

How can my family and friends help?
One of the most valuable pieces of information a doctor can get is an accurate eyewitness description of a typical event. It is worthwhile for people who have seen your seizures to visit the doctor’s office with you. If that is not practical, perhaps the doctor or nurse can speak with them by telephone.

Ask them to write down a detailed description of what they saw soon after the event, because memories fade with time. Even after they talk to your doctor, save these notes, because they may be helpful to another doctor later. If the episodes occur often, it would be very helpful for the doctor if someone could film one or more of them on home video.

Your parents or other family members also may be able to help with some important questions about your medical history:

• Was your birth difficult?
• Did you have any seizures with high fevers when you were a baby or small child?
• Did you ever have a head injury? If so, did you lose consciousness ConsciousnessState of awareness; if consciousness is preserved during a seizure, the person can respond (either in words or actions, such as raising a hand on command) and recall what occured during the spell.Closeafter the injury? How long were you unconscious? Were you taken to a hospital?
• Did you ever have meningitis MeningitisA bacterial infection of the membranes surrounding the brain; often diagnosed by a spinal tap (lumbar puncture).Close(an infection of the membranes around the brain and spinal cord) or encephalitis EncephalitisAn inflammation of the brain, usually caused by a virus.Close(a serious viral infection of the brain)?
• Has anyone else in the family had epilepsy, any other neurological disorder, or a disorder associated with loss of consciousness?

What else should I tell the doctor about?
If the incidents occur repeatedly, try to identify associated factors. For example, some women with epilepsy have more frequent episodes at certain times in their menstrual cycle, so you may want to track this kind of relationship on a calendar. Some people try to link their seizures with environmental factors such as stress, using an antibiotic, or eating too much sugar. Often these associations are just coincidences. Keep careful records of when the possible factor occurs in relation to the time and frequency of your seizures. And remember that even if the factor and your seizures turn out to be associated, that doesn't necessarily mean that the factor is causing the seizures.

Physical Exam

Looking for other disorders
Medical disorders involving other systems of the body can cause seizures, so your doctor will perform a general medical examination as an important part of your first visit for seizures. An examination and some laboratory tests can tell the doctor whether your liver, kidneys, and other organ systems are working properly.

Some people have both epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closeand a medical disorder such as kidney disease or an overactive thyroid gland. If you have a disorder of this kind, both your neurologist and your primary doctor should know about it. Your medical disorder may be involved in causing your seizures. Even if it is not, the presence of another disorder may affect the seizure SeizureA sudden, excessive discharge of nervous-system electrical activity that usually causes a change in behavior.Closemedicines that are prescribed for you. Either the disorder itself may affect the way the medicine works in your body, or the medicine prescribed to treat it may interact with your seizure medicine.

Neurological Exam

Assessing thinking, function, and senses
A neurological examination looks at how well your brain and the rest of your nervous system are functioning. Every time your doctor taps your knee with a hammer to see if your foot jumps, that's part of a neurological exam.

If you have spells that may be seizures, your primary doctor probably will send you to see a neurologist, a doctor who specializes in the brain and nervous system. The neurologist will perform a complete neurological exam to find out whether an area of your brain is functioning abnormally.

Usually the neurologist will first ask you about problems you may have experienced that could be a sign of a brain disorder. The neurologist also will test the functioning of your muscles, your senses, and your reflexes, and will look for any problems with your walking or coordination. Another part of the exam is a test of your mental functions, such as the ability to remember words, do arithmetic, and name objects.

During follow-up visits, the neurologist often will perform a brief version of the exam again to see if anything has changed. If the dosage of your seizure SeizureA sudden, excessive discharge of nervous-system electrical activity that usually causes a change in behavior.Closemedicine is too high, for instance, this exam may reveal unwanted side effects, such as

• slurred speech
• trouble concentrating
• difficulty walking a straight line
• jerking eye movements when you look to one side
• trembling when your arms are outstretched

If the neurologist finds signs like these, the dosage of medicine may need to be reduced.

The neurologist may be examining you even while you are just talking. The doctor can assess your mood, thinking, language, eye and facial movements, strength, coordination, and many other features just by carefully listening and observing you.

EEG

Checking brain waves
EEG is the name commonly used for electroencephalography (e-LEK-tro-en-SEF-uh-LOG-rah-fee). EEG is the most important test for diagnosing epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closebecause it records the electrical activity of the brain. It is safe and painless. Electrodes (small, metal, cup-shaped disks) are attached to your scalp and connected by wires to an electrical box. (The wires can only record electrical activity; they do not deliver any electrical current to your scalp.) The box in turn is connected to an EEG machine.

The EEG machine records your brain's electrical activity as a series of squiggles called traces. Each trace corresponds to a different region of the brain. EEGs always used to be recorded on paper, but computerized, paperless EEGs are now used more often.

What can the EEG show?
The EEG shows patterns of normal or abnormal brain electrical activity. Some abnormal patterns may occur with a number of different conditions, not just seizures. For example, certain types of waves may be seen after head trauma, TraumaAn injury or wound caused by external force or violence.Close stroke, brain tumor, or seizures. A common example of this type is called "slowing, SlowingA term used to describe a group of brain waves on the EEG that have a lower frequency than expected for the subject’s age and level of alertness and the area of the brain recorded. Slow waves can result from drowsiness or sleep, drugs, or brain injuries and occur during or after seizures.Close" in which the rhythm of the brain waves is slower than would be expected for the patient's age and level of alertness.

Certain other patterns indicate a tendency toward seizures. Your doctor may refer to these waves as "epileptiform EpileptiformResembling epilepsy or its manifestations; may refer to a pattern on the EEG associated with an increased risk of seizures.Closeabnormalities" or "epilepsy waves." These include spikes, sharp waves, and spike-and-wave discharges. Spikes and sharp waves in a local area of the brain, such as the left temporal lobe, indicate that partial seizures are beginning in that area. Primary generalized epilepsy, on the other hand, is suggested by spike-and-wave discharges that are widely spread over both hemispheres of the brain, especially if they begin in both hemispheres at the same time.

Procedure

Usually your brain waves will be recorded for about 20 to 40 minutes. It takes about the same amount of time to prepare for the recording, so the entire procedure usually takes 1 to 1½ hours. You can help by washing your hair the night before or the day of the test. Don't use any conditioners, hair creams, sprays, or styling gels.

The test is performed by an EEG technologist. First the technologist will measure your head so that the electrodes can be placed in the correct position. A wax crayon, which can be easily washed off later, is used to mark the points on your scalp where the electrodes should be placed.

Usually the electrodes are held in place by a paste that can be washed off easily when the test is over. The technologist will probably scrub each position on your scalp with a mildly abrasive cream before applying the electrodes. This will help improve the quality of the recording.

The EEG is recorded in a quiet room, which often is dimly lit. The technologist may ask you to open and close your eyes several times, may shine flashing lights into your eyes, or may ask you to breath rapidly or deeply. If you have any symptoms of a seizure SeizureA sudden, excessive discharge of nervous-system electrical activity that usually causes a change in behavior.Closeduring the test, tell the technologist.

If you fall asleep briefly during the session, that's fine. It may even be helpful, because an EEG obtained during while you are asleep may provide extra information. Sometimes doctors ask patients to stay up the entire night before an EEG is performed because sleep deprivation can increase the likelihood that waves indicating epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closewill be recorded.

After the EEG recording is done, the technologist will remove the electrodes from your scalp, and you can go home and wash the paste out of your hair. The doctor usually reads the EEG after you have left and will tell you the results later.

What can the EEG show?
The EEG shows patterns of normal or abnormal brain electrical activity. Some abnormal patterns may occur with a number of different conditions, not just seizures. For example, certain types of waves may be seen after head trauma, TraumaAn injury or wound caused by external force or violence.Close stroke, brain tumor, or seizures. A common example of this type is called "slowing, SlowingA term used to describe a group of brain waves on the EEG that have a lower frequency than expected for the subject’s age and level of alertness and the area of the brain recorded. Slow waves can result from drowsiness or sleep, drugs, or brain injuries and occur during or after seizures.Close" in which the rhythm of the brain waves is slower than would be expected for the patient's age and level of alertness.

Certain other patterns indicate a tendency toward seizures. Your doctor may refer to these waves as "epileptiform EpileptiformResembling epilepsy or its manifestations; may refer to a pattern on the EEG associated with an increased risk of seizures.Closeabnormalities" or "epilepsy waves." These include spikes, sharp waves, and spike-and-wave discharges. Spikes and sharp waves in a local area of the brain, such as the left temporal lobe, indicate that partial seizures are beginning in that area. Primary generalized epilepsy, on the other hand, is suggested by spike-and-wave discharges that are widely spread over both hemispheres of the brain, especially if they begin in both hemispheres at the same time.

Where it's performed

The EEG is the principal test for confirming a diagnosis of seizures and gathering information about their type and location. It can be performed in a neurologist’s office but sometimes patients are sent to a hospital to have the EEG performed in the neurology or epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closedepartment. Whichever situation you are in, you may wonder whether your EEG will be of the same quality as an EEG performed in a different setting.

All else being equal, the location of the EEG equipment should not make any difference in itself. There are standard procedures for the placement of the EEG electrodes and for the way the test is performed and interpreted. Differences may arise, however, if one site has newer equipment or more experienced professionals to perform and interpret the test.

What are the advantages of the newest equipment?
You have probably seen pictures of basic EEG machines that draw the brain waves on long paper strips. New computerized (digital) EEG machines do not produce paper strips. Instead, they offer more options for viewing brain waves than the basic paper EEG machine.

One of the most important differences is that they allow the neurologist to look at more channels in searching for abnormal brain waves. The basic paper EEG machine provides from 8 to 21 channels, but many digital EEG machines offer 32 channels or even more. (Some have fewer than 32.) Viewing more channels increases the possibility of finding the "epilepsy waves" and helps confirm the diagnosis of either partial or generalized epilepsy.

Another advantage of the newer equipment is that with computerized recording, the neurologist can reformat the brain waves and view the same period of recording from a different perspective. With paper recording, such reformatting is not possible.

How important is the skill of the person interpreting my EEG?
EEG interpretation is an acquired skill. Neurologists with extensive experience in reading EEGs can provide more accurate interpretations than those with limited experience. Neurologists who specialize in reading EEGs (neurophysiologists) read hundreds of them during their training so they can become skilled at interpreting them.

They learn, for instance, to recognize the many things besides seizure SeizureA sudden, excessive discharge of nervous-system electrical activity that usually causes a change in behavior.Closeactivity that can alter an EEG recording. Opening the eyes, mental concentration, breathing fast, or looking at flickering lights all alter brain-wave patterns. If you move (by closing your mouth, for example), that creates changes in the EEG called artifact.

Experienced neurologists also learn to recognize the slight differences between what is normal for one patient versus what is normal for someone else. Subtle changes in brain waves may be interpreted as abnormal when the actual change is this kind of normal variant.

Interpreting EEGs also involves some subjectivity and judgment. (This is why the machine doesn't just spit out the interpretation along with the strip!) What one interpreter reads as sharp waves may be read as spikes by another. Both may be considered correct, depending on the criteria they apply. Experienced neurologists also learn to interpret the EEG in light of the patient's medical history, Medical historyThe account of a patient's disorder.Close physical examination, and other laboratory studies.

What are other advantages of having my EEG performed in a hospital?
Epilepsy centers in hospitals generally use state-of-the-art equipment. The neurologists who work there have gone through special training in diagnosing and treating epilepsy. They may also have special qualifications in interpreting EEGs.

If your EEG is performed in a hospital or a large office practice, more than one neurologist may be able to review it. Such second opinions can decrease subjectivity and bias. Additional interpreters also can apply a wider range of experience to questions that may arise.

Even with the best technology and the most highly trained neurologists, however, your first EEG may turn out to be normal or inconclusive. You may need to have another EEG performed after sleep deprivation, or have ambulatory or video-EEG monitoring to record the epilepsy waves that are associated with your seizure activity.

Special electrodes

If a routine EEG does not give all the information the doctor needs for the diagnosis and treatment of your epilepsy, EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Close occasionally special types of electrodes are used to get more information:

• Sphenoidal (sfee-NOY-dle) electrodes can record electrical activity from deep parts of the temporal and frontal lobes. They are used most often used during video-EEG monitoring studies. The technologist or doctor will swab your cheek just below your jaw hinge with rubbing alcohol, and may apply an anesthetic. Then a thin needle, carrying a thin wire, is inserted into the cheek. The needle is removed, and the wire is taped to your skin. You should experience little discomfort.
   
• Nasopharyngeal (NAY-zo-fa-RIN-je-al) electrodes are used occasionally to record electrical activity deep in the brain. They are now being used less often, however, because they involve some discomfort and doctors have found that regular electrodes often can provide the same information. These electrodes are plastic tubes with a wire inside, ending with a blunt metal tip. The electrodes are inserted through the nose until the metal tip is located in the upper back part of the nose (the nasopharynx). There may be some discomfort while the electrodes are being inserted. They are left in place for about 20 or 30 minutes during the study.

Ambulatory EEG

Why do I need one?
The brain’s electrical activity fluctuates from second to second, but routine EEGs provide only a 20- to 40-minute sample of this activity. If epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closewaves occur in your brain only once every 3 or 4 hours, or if they happen only after an hour of sleep, for instance, a routine EEG will usually be normal. Then the doctor may want to see a longer recording that includes prolonged periods when you are both awake and asleep. This kind of recording is called an ambulatory EEG. ("Ambulatory" [AM-byew-lah-TOR-ee] means able to walk around.)

An ambulatory EEG may be performed to confirm the diagnosis of epilepsy if you've continued to have seizures despite trying various seizure SeizureA sudden, excessive discharge of nervous-system electrical activity that usually causes a change in behavior.Closemedicines. It would generally be performed at a specialized epilepsy center.

What's the procedure like?
This kind of recording is made by using a special recorder that is slightly larger than a portable cassette player. You can wear it on your waist, with the wires running either under your shirt or outside of it. Then you can go about your normal routine for up to 24 hours. The electrodes are pretty well covered if you have a full head of hair, but most people prefer not to go to school or work while wearing them.

Because the electrodes must stay on your head longer than for a regular EEG, the technologist will probably use a special glue called "collodion" to keep them in place. Acetone or a similar solution is used to remove them easily at the end of the test.

You will usually be asked to keep a diary of your actions during the day to help the doctor identify the cause of abnormal activity on the recording. For instance, the electrodes may make your head itchy, and if you scratch it, that may appear as abnormal activity on the EEG.

What are the special features of ambulatory EEG recorders?
Most recorders have an "event" button for you to press if you experience any of the symptoms for which you are being tested, such as feeling "spacey" or confused. If you are unable to press the button during a seizure, someone else can do it for you.

Newer recorders have built-in programs to identify epilepsy waves and seizures. Some even have video recording capability.

Video EEG

In video-EEG, you are videotaped at the same time as your EEG is recorded. The recording is carried out for a long period of time, often several days. The doctor usually views the video and EEG images side by side on a split screen. In this way the doctor can see precisely how your behavior during seizures is related to the electrical activity in your brain.

Video-EEG can be done on outpatients but it is often done in the hospital. If you are in the hospital under close supervision, it is safe to allow you to have some seizures, which the doctor can study. The doctor may reduce or even stop your seizure SeizureA sudden, excessive discharge of nervous-system electrical activity that usually causes a change in behavior.Closemedicines to make seizures more likely. Other techniques include sleep deprivation, hyperventilation HyperventilationIncreased rate and depth of breathing; may be done during the EEG to increase the chances of finding epileptiform or other abnormal activity.Close(very rapid or deep breathing), and exercise.

Video-EEG is most helpful in determining whether seizures with unusual features are actually epilepsy, EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Close identifying the type of seizures, and pinpointing the region of the brain where seizures begin. Locating the region precisely is essential if epilepsy surgery is being considered.

Video-EEG tips
A lot of patients say it's boring, just sitting around the hospital day after day. So bring things to read or something else to keep you busy.

Another tip is that the clothing you bring should be things that you don't have to pull over your head. The electrodes will be glued to your scalp with collodion, the same extra-strong glue that is used for ambulatory EEG, so your head will be connected to the EEG machine for long stretches of time.

Looking at the Brain

What is neuroimaging?
Sometimes epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closeis caused by abnormalities in the structure of the brain. These can be such things as too much spinal fluid (hydrocephalus) HydrocephalusA condition associated with obstruction of the cerebrospinal fluid pathways in the brain and accumulation of excess cerebrospinal fluid within the skull.Close, scar tissue, or a tangle of blood vessels (vascular malformation). Tests that can take pictures of the brain, called "neuroimaging," can tell doctors whether you have one of these conditions. These tests are performed to look for the cause of your seizures (which can be identified for about half of patients) or to make sure that you don't have some other medical condition.

The most common neuroimaging tests for epilepsy are computed tomography Computed tomography (CT)A scanning technique that uses x-rays and computers to create pictures of the inside of the body; shows the structure of the brain; not as sensitive as MRI.Close(CT or CAT scan) and magnetic resonance imaging Magnetic resonance imaging (MRI)A scanning technique that creates pictures of the inside of the body and the brain; uses a strong magnet (does not use x-rays); more sensitive than CT.Close(MRI). Both produce a picture of how the brain looks. MRI is preferred because it provides more information than CT. In fact, MRI is recommended as the imaging test of choice.

What neuroimaging studies do I need?
For some types of epilepsy, a neuroimaging study may not be necessary. For most people with newly diagnosed epilepsy, however, neuroimaging is important for the diagnosis.

Neuroimaging should always be considered if the cause of your seizures is something that is apt to change, such as a benign BenignFavorable for recovery.Closetumor, which may grow, or a vascular malformation, which could bleed. In these situations, your doctor may want you to have follow-up scans to keep an eye on the situation. MRI also can be helpful if the cause of your seizures is suspected but indefinite, such as a mild head injury.

Many doctors will not order a CT or MRI scan for patients with certain well-defined epilepsy syndromes that are often genetic, such as absence seizures, juvenile myoclonic epilepsy, Juvenile myoclonic epilepsy (JME)A primary generalized epilepsy syndrome, usually beginning between ages 5 to 17 years, characterized by myoclonic (muscle-jerk) seizures and possibly also absence and tonic-clonic seizures; responds well to valproate.Close or benign rolandic epilepsy, Benign rolandic epilepsyAn epilepsy syndrome Epilepsy syndromeA disorder defined by seizure type, age of onset, clinical and EEG findings, family history, response to therapy, and prognosis.Closeof childhood characterized by partial seizures occuring at night and often involving the face and tongue; the seizures may progress to tonic-clonic seizures, have a characteristic EEG pattern, are easily controlled with medications but may not require treatment, and are outgrown by age 16 years.Close because the results are almost always normal or unrelated to epilepsy.

What are less common forms of neuroimaging?
CT and MRI show the brain’s structure, or how it looks. Other neuroimaging methods show its function, or how it works. They are generally used to evaluate patients before epilepsy surgery or as research tools. These methods include:

• Single-photon emission computed tomography (SPECT), which shows a map of blood flow through different parts of the brain.
• Positron emission tomography (PET), which shows how much sugar (glucose) or oxygen is metabolized (used up) by various areas of the brain.
• Magnetoencephalography (MEG), which measures tiny magnetic fields to study the brain's electrical patterns with less interference from the skull and other tissues than on an EEG.
• Magnetic resonance spectroscopy (MRS), which examines signals generated by elements such as phosphorus. MRS uses technology similar to that of MRI, which studies hydrogen atoms. MRS data can be used, for example, to learn about metabolism MetabolismThe physical and chemical processses by which substances are produced or transformed (broken down) into energy or products for the uses of the body.Closein the brain.
• Ultrasound, which can look at fluid or blood in the brain of a newborn baby

Computed tomography (CT)

Computed tomography (CT or CAT scan) was introduced in the United States in the early 1970s. It revolutionized the practice of neurology and neurosurgery by letting doctors see inside the brain without surgery for the first time. The CT scan is normal in most people with epilepsy. EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Close Abnormalities that might be seen are atrophy (shrinking of the brain), scar tissue, strokes, tumors, or abnormal blood vessels.

Like ordinary x-rays, CT scans expose the patient to radiation. However, the amount is low and the procedure is safe even if it needs to be repeated several times. The scanner is a large machine, but less confining for patients than the machine used for MRI.

The advantages of CT scanning include speed and easy availability in most places. It has lower resolution than MRI for showing brain structures, however, and it is not as good at discriminating between the brain's gray matter and white matter.

MRI

MRI (magnetic resonance imaging) Magnetic resonance imaging (MRI)A scanning technique that creates pictures of the inside of the body and the brain; uses a strong magnet (does not use x-rays); more sensitive than CT.Close was first introduced in the United States in the early 1980s. It is the most important neuroimaging test in epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closebecause it shows more details of the brain's structure than does the cat scan. MRI does not use x-rays. Instead, it uses a powerful magnet to change the spin on atomic particles in the body. Then it measures the changes in the magnetic field as the particles resume their previous course. This is safe and you will not feel anything while it is happening. (See photos of the MRI procedure.)

MRI produces a remarkably accurate representation of the brain's structure. The images are extremely helpful for identifying scar tissue, areas of abnormal brain development DevelopmentThe process of physical growth and the attainment of intelligence and problem-solving ability that begins in infancy; any interruption of this process by a disease or disorder is called developmental delay.Close(dysplasia), small brain tumors, blood vessel abnormalities, and changes in the brain's white matter.

SPECT

SPECT (single-photon emission computed tomography) Computed tomography (CT)A scanning technique that uses x-rays and computers to create pictures of the inside of the body; shows the structure of the brain; not as sensitive as MRI.Close shows the blood flow in the brain. A safe, very low-level radioactive compound is injected into your arm, and the particles it emits are measured. The more blood that flows through a certain area, the more particles are emitted. The result is displayed as a picture with different colors representing different levels of blood flow.

This test is readily available in most hospitals, but it is seldom needed routinely in epilepsy. EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Close SPECT scans obtained during or immediately after a seizure SeizureA sudden, excessive discharge of nervous-system electrical activity that usually causes a change in behavior.Closemay show increased blood flow in the area where seizures arise. Scans performed between seizures can be misleading, however.

New computer techniques allow doctors to measure the differences between SPECT scans taken during and between seizures to obtain "subtraction" SPECT images. These can be superimposed onto the patient's MRI in an effort to pinpoint the seizure focus. FocusThe center or region of the brain from which seizures begin; used in reference to partial seizures.Close This technique may be most helpful when seizures begin outside the temporal lobe and MRI scans do not show a structural abnormality.

PET

PET (positron emission tomography) shows the brain's use of oxygen or sugar (glucose). As with SPECT, a very low, safe dose of a radioactive substance is injected into your arm and the scanner records its circulation. Not all types of PET scans look alike, but often different colors are used to show areas of higher or lower use of oxygen or sugar.

This test can help to identify the area of the brain from which partial seizures arise. It may be performed in the period between seizures, the interictal InterictalReferring to the period between seizures.Closeperiod. PET scans are expensive, and very few patients with epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closeneed them. Many insurance companies will pay for PET scans for patients who are being evaluated for epilepsy surgery.

MEG (Magnetoencephalography)

MEG (magnetoencephalography) Magnetoencephalography (MEG)Recording the brain's magnetic activity, which is generated by its electrical activity.Close provides a new noninvasive tool to study epilepsy EpilepsyA disorder characterized by transient but recurrent disturbances of brain function that may or may not be associated with impairment or loss of consciousness and abnormal movements or behavior.Closeand brain function. When it is combined with structural imaging, it is known as magnetic source imaging (MSI).

MEG measures small electrical currents arising inside the neurons of the brain. These currents produce small magnetic fields. MEG generates a remarkably accurate representation of the magnetic fields produced by the neurons.

To some degree, MEG is similar to EEG (electroencephalography). An important difference is that the skull and the tissue surrounding the brain affect the magnetic fields measured by MEG much less than they affect the electrical impulses measured by EEG. The advantage of MEG over EEG is therefore greater accuracy owing to the minimal distortion of the signal. This allows for more usable and reliable localization of brain function. When MEG is added to magnetic resonance imaging (MRI), which shows brain structure, the combination of the images is extremely helpful for identifying areas of the brain that may be generating a potential for seizures, as well as for localizing the electrical activity in normal brain function.

Why is an MEG performed?
In the evaluation of epilepsy, MEG is used to localize the source of epileptiform EpileptiformResembling epilepsy or its manifestations; may refer to a pattern on the EEG associated with an increased risk of seizures.Closebrain activity, which most likely is the source of seizures. It is usually performed with simultaneous EEG.

MEG may be helpful in the following situations:

• It can improve the detection of potential sources of seizures by revealing the exact location of the abnormalities, which may then allow physicians to find the cause of the seizures.
• It can help when MRI scans show a lesion but the EEG findings are not entirely consistent with the MRI information. An MEG may be able to confirm that the epileptiform discharges (the brain waves typical of epilepsy) are indeed arising from the lesion. Then a decision can be made regarding surgery.
• In patients who have brain tumors or other lesions, the MEG may be able to map the exact location of the normally functioning areas near the lesion so that surgery can be planned to minimize postoperative weakness or loss of brain function.
• In patients who have had past brain surgery, the electrical field measured by EEG may be distorted by the changes in the scalp and brain anatomy. If further surgery is needed, MEG may be able to provide necessary information without invasive EEG studies.

Preparing for the MEG procedure
No special preparations are needed for an MEG, unless sedation is planned. Then you (or your child) may be asked not to eat after midnight. Regular medicines should be taken with a little bit of water.

When you go for the MEG, wear loose, comfortable clothing. Do not wear jewelry, hair spray, make-up, hearing aids, or removable dental work.

If you have a vagus nerve stimulator Vagus nerve stimulator (VNS): A pacemaker-like device, implanted in the upper chest, which stimulates a nerve in the left neck and can reduce seizure activity. Close(VNS) or pacemaker, you may not be able to have MEG. Ask your doctor.

What will happen in the MEG lab?
You will be asked a series of medical questions to ensure that your body does not contain any metallic objects that may interfere with the MEG. A videotape eraser will be moved over your head to erase magnetic activity from fillings in your teeth. You will also be asked about any previous surgeries.

You will need to remove all clothing that has metal (such as zippers, snaps, or sparking paint) and change into a hospital gown or pants. Then EEG electrodes will be glued all around your head and one will be placed over your heart. Three small coils will be taped to your forehead and you will wear two other coils attached to earplugs. You will be asked to lie down on an MEG bed, where a small metal coil will touch all the different dots around your head to record its shape, and this information will go into the computer. During this time you will be asked to lie perfectly still. After your head shape has been recorded in the computer, you will get ready for the MEG study itself. You may be given pillows to put under your knees and elbows, and blankets to keep you warm, so you will be comfortable. The sensors will be put over your head but will not cover your face. (See photo) The coils and EEG electrodes will be plugged into the sensors. When you are comfortable, your family and the technologist will leave the room and the door will be closed. Closing the door can be a little scary, but you will have a small microphone so you can talk to the technologist, who can come into the room at any time.

The MEG test will take between 1 hour and 2 1/2 hours. During this time, you will need to remain as still as possible, not moving your head. This is very important. If you need a break, tell the technologist.

Sometimes stimulation tests are performed. If you have this kind of test, little plastic sensors may be placed on your fingers, or you will be shown a video with different colors. By doing this test, the doctors will know which part of your brain controls your hands, feet, and vision.

After this information is acquired, you will be removed from the MEG room. You can change back into your regular clothes and go home. Technicians and doctors will later review the information and report the results to your referring doctor.

MEG unit. The individual's head rests inside
the MEG unit during the study.