Most epileptic seizures are either partial seizures, which affect just one part of the brain, or generalized seizures, which affect both sides of the brain at the same time.

Seizures differ in many ways, both in the form they take and in the way they make you feel. Some people experience only one type of seizure; others experience more than one type, or a combination. Part of taking control of your seizures is to learn all you can about how they happen and what treatments can help you to prevent them. You’ll find brief descriptions of the different seizure types listed below.

Partial Seizures
Partial seizures (also called focal seizures) affect just one part of your brain. Partial seizures can interfere with your awareness and your ability to communicate; they can also make your body move in ways that you can’t control.

Partial seizures are the most common type of seizure. A partial seizure can stimulate your emotions and your senses, make your body move, interfere with your perceptions, generate perceptions, and produce vivid, extended hallucinations that you can see or hear.

Sometimes a partial seizure will trigger a generalized seizure. In medical language, this is called a partial seizure secondarily generalized.

Simple Partial Seizures: During a simple partial seizure, you remain conscious, though you may not be able to move or communicate. Parts of your body may move, twitch, or shake. You may feel nauseated; your skin may flush, go pale, or get goose bumps. Your own body, and the things and the space around you, may seem warped and unfamiliar, and you may experience sensations, sights, sounds, smells, and tastes caused only by your seizure.

You may feel a powerful sense of déjà vu, and visions from your past may seem to appear. You may also have a burst of extreme emotion, which—however wonderful or wrenching or scary it may seem at the time—is just another part of your seizure.

Despite all this, when it is all over—since you have been conscious the entire time—your memory of the event may be quite clear.

Complex Partial Seizures: During a complex partial seizure (also known as temporal lobe epilepsy or psychomotor epilepsy), although your eyes may stay open and you may move around, you will probably be unconscious. If you can speak, your words are unlikely to make sense. You will be unable to control how you move or what you say and do.

A complex partial seizure may begin with a blank stare and a loss of consciousness and continue through a number of events, some of which may include mumbling and other movements of the mouth; mechanical, repetitive activities; wandering around or going through seemingly routine tasks; talking or crying out; disturbed reactions, as if you were having a nightmare; and various agitated motions—all just part of your seizure.

When you emerge from a complex partial seizure, you will have no memory of what has taken place.

Generalized Seizures
Generalized seizures affect both sides of the brain at the same time from the time the seizure begins. You lose consciousness—often for a short time, but sometimes for much longer.

Absence Seizures: An absence seizure (also known as petit mal) can happen so quickly that it can sometimes go unnoticed. Absence seizures begin suddenly and end suddenly, without any prior warning or aftereffect. You experience a sudden—but fleeting—loss of awareness, sometimes accompanied by staring.

Absence seizures are more commonly experienced by children, though adults also have them. With some absence seizures your eyelids or facial muscles will twitch, or certain muscles may go slack. When an absence seizure lasts longer than usual, automatic movements can also occur.

Atonic Seizures: During an atonic seizure (also known as a drop attack, an astatic seizure or an akinetic seizure), some of your muscles suddenly go limp. Your head may fall to your chest, your legs buckle, your posture slip and droop; you may even collapse. Because there’s no warning—and no time to position yourself or prevent a fall—you may hit your head or face. Atonic seizures are not easy to control with medicines. If you are subject to atonic seizures, you may need to wear headgear to protect yourself from injury.

Myoclonic Seizures: During a myoclonic seizure, your muscles contract rapidly for a brief time. You make sudden jerking motions on both sides of your body or sometimes in one foot or arm. While you probably will not need first aid, you should see a healthcare professional if you’ve just had a myoclonic seizure for the first time.

Tonic-Clonic Seizures: During a tonic-clonic seizure (also known as grand mal or convulsions), you stiffen (the tonic phase) and your limbs and face begin to jolt and shake (the clonic phase). During the tonic phase, your breathing may slow down or even pause. In a typical tonic-clonic seizure, when the convulsive movements begin, breathing returns. The jerking and jolting of the clonic phase often lasts less than a minute.

Tonic-clonic seizures occur in different ways. Some people experience only the initial stiffening; others experience only the jerking motions. For some people, a tonic-clonic seizure may begin with an atonic seizure.

The muscles that control continence may be among those that contract and relax rapidly during the clonic phase. Although you may bite your tongue or parts of your mouth during a tonic-clonic seizure, you cannot "swallow your tongue" as some myths insist.

After a tonic-clonic seizure, you may feel confused and thoroughly exhausted; you may also have a headache. Your body and your brain will need rest. Expect it to take a little while—from a few minutes to some hours—to feel entirely yourself again.

If breathing does not return quickly after the tonic phase, if a seizure goes on for more than 5 minutes, or if another seizure or series of seizures follows the first, you will need emergency medical care.

Tonic Seizures
What are they like?
Here's a typical story: "When Jeff has an episode, he just stiffens up. Both arms are raised over his head and his face has a grimace, as if someone is pulling on his cheeks. If he's standing, he may lose his balance and fall. These seizures don't knock him out like the tonic-clonic seizures, but if he has a few close together, he is often tired."

How long do they last?
Usually less than 20 seconds.

Tell me more
Muscle "tone" is the muscle's normal tension at rest. In a "tonic" seizure, the tone is greatly increased and the body, arms, or legs make sudden stiffening movements. Consciousness is usually preserved. Tonic seizures most often occur during sleep and usually involve all or most of the brain, affecting both sides of the body. If the person is standing when the seizure starts, he or she often will fall.

Nonepileptic Seizures
Some people have brief episodes that resemble epileptic seizures, yet they are not caused by electrical disturbances in the brain. Although sometimes difficult for an observer to distinguish from a true epileptic seizure, these nonepileptic seizures have nothing to do with epilepsy.

Status Epilepticus
Most seizures are brief. But when your seizures go on for too long or come in clusters, you are at risk for a condition called status epilepticus—an ongoing state of seizure or multiple seizures with continued loss of consciousness. If this happens to you, you will need emergency treatment. If you’re identified to be at risk for status epilepticus, work with your healthcare professional to ensure that you have a plan of action in place that will get you immediate treatment in case of a seizure emergency.

About Syndromes
Healthcare professionals use the word syndrome to describe a set of symptoms that tend to appear together under similar circumstances and respond to certain treatments.

Lennox-Gastaut syndrome, for example, is one of the most severe forms of epilepsy; it accounts for up to 10% of all cases of childhood epilepsy. It usually develops in children between 1 and 8 years of age, with 3 the average age of onset.2 (For more, see our Web page About Lennox-Gastaut Syndrome.

Diagnosis
People who have at least two unprovoked seizures that occur at different times have a seizure disorder. A diagnosis is made based on the person's history and the observations of eyewitnesses. Seizures may be suspected if symptoms such as loss of consciousness, muscle spasms that shake the body, loss of bladder control, sudden confusion, and an inability to pay attention occur. However, true seizures are much less common than most people think; most episodes of brief unconsciousness are more likely to be fainting (syncope (see Low Blood Pressure: Fainting).

An eyewitness report of the episode can be very helpful to doctors. An eyewitness can describe exactly what happened, whereas the person who had the episode usually cannot. An accurate description of the circumstances is needed: how fast the episode started; whether it involved abnormal muscle movements (such as spasms of the head, neck, or facial muscles), tongue biting, or loss of bladder control; how long it lasted; and how quickly the person recovered. Doctors also need to know what the person experienced before the episode: whether the person had a premonition or warning that something unusual was about to happen and whether anything, such as certain sounds or flashing lights, seemed to trigger the episode.

To help diagnose a seizure disorder, doctors use electroencephalography (EEG), a painless, safe procedure that records electrical activity in the brain (see Diagnosis of Brain, Spinal Cord, and Nerve Disorders: Electroencephalography). Doctors examine the recording (electroencephalogram) for evidence of abnormal electrical discharges. Because abnormal discharges are more likely to occur after too little sleep, EEG is sometimes scheduled after a person has been deprived of sleep for 18 to 24 hours. Even if a seizure did not occur during EEG, abnormalities may be present. Because of the limited recording time, EEG can miss abnormalities and the electroencephalogram may appear normal, even in people who have a seizure disorder.

Brain Activity During a Seizure An electroencephalogram (EEG) is a recording of the brain's electrical activity. The procedure is simple and painless. About 20 small adhesive electrodes are placed on the scalp, and the brain's activity is recorded under normal conditions. Then the person is exposed to various stimuli, such as bright or flashing lights, to try to provoke a seizure. During a seizure, electrical activity in the brain accelerates, producing a jagged wave pattern. Such recordings of brain waves help identify a seizure disorder. Different types of seizures have different wave patterns.

Once a seizure disorder is diagnosed, more tests are usually needed to identify the cause. Routine blood tests are performed to measure the levels of sugar, calcium, and sodium in the blood and to determine whether the liver and kidneys are functioning properly. A complete blood count is performed to determine how many white and red blood cells are present. A high white blood cell count may indicate an infection. A low red blood cell count (anemia) may indicate an inadequate supply of oxygen to the brain. Often, electrocardiography (ECG) (see Symptoms and Diagnosis of Heart and Blood Vessel Disorders: Electrocardiography) is performed to rule out an abnormal heart rhythm as a possible cause of symptoms. Because an abnormal heart rhythm can reduce blood flow (and therefore the oxygen supply) to the brain, it can trigger seizures and cause loss of consciousness.

Computed tomography (CT) or magnetic resonance imaging (MRI) of the head is usually performed to check for structural damage to brain tissue (for example, by a stroke). Sometimes a spinal tap (lumbar puncture (see How a Spinal Tap Is Performed) is needed to determine whether the person has an infection of the layers of tissue covering the brain (meningitis) or of the brain (encephalitis).
....referenced, Merck

Treatment
If the cause can be identified and eliminated, no additional treatment is necessary. For example, if low sugar (glucose) levels in the blood (hypoglycemia (see Hypoglycemia) caused the seizure, glucose is given to increase the levels and the disorder causing the low levels is treated. Other treatable causes include a tumor, an infection, and abnormal sodium levels.

Anticonvulsants may be needed to reduce the risk of having another seizure. Anticonvulsants are not usually prescribed for people who have had only one generalized seizure for which no cause can be found. But they are necessary for people who have had more than one, unless the cause has been identified and completely eliminated.

Anticonvulsants can completely prevent convulsive seizures in more than half of the people who have them and greatly reduce the frequency of seizures in another third. These drugs are only slightly less effective for absence seizures. Half of the people who respond to anticonvulsants can eventually discontinue them without having a relapse. However, for about 10 to 20% of people with a seizure disorder, anticonvulsants do not adequately prevent seizures.

No one drug can control all types of seizures. For most people, seizures can be controlled with a single drug. If seizures recur, different anticonvulsants are tried. Determining which anticonvulsant is effective may take several months. Some people have to take several drugs.

For women who have a seizure disorder and are pregnant, taking an anticonvulsant increases the risk of miscarrying or of having a baby with a birth defect (see Some Drugs That Can Cause Problems During Pregnancy*). However, stopping the anticonvulsant may be more harmful to the woman and the baby.

Because status epilepticus is an emergency, large intravenous doses of one or more anticonvulsants are given as quickly as possible. Measures to prevent injuries are taken during the prolonged seizure.

Anticonvulsants, though very effective, may have side effects. Many cause drowsiness but, paradoxically, sometimes cause hyperactivity in children. Blood tests are performed periodically to determine whether an anticonvulsant is affecting the kidneys, liver, or blood cells. People taking anticonvulsants should be aware of possible side effects and should consult their doctor at the first sign of side effects.

The dose of an anticonvulsant is critical: The best dose of an anticonvulsant is the smallest dose that stops all seizures while causing the fewest side effects. Doctors ask the person about side effects, then adjust the dose if needed. Sometimes doctors also measure the level of anticonvulsant in the blood. Anticonvulsants should be taken just as prescribed. No other drugs should be taken at the same time without the doctor's or pharmacist's authorization because many drugs alter the level of anticonvulsant in the blood. People who take anticonvulsants should see a doctor regularly for dose adjustment and should always wear a Medic Alert bracelet inscribed with the type of seizure disorder and the drug being taken.

Exercise is recommended and social activities are encouraged. However, people who have a seizure disorder may have to make some adjustments. For example, they should not drink alcoholic beverages. They should not engage in activities where a sudden loss of consciousness could result in serious injury: They should not swim alone or operate power tools. In most states, laws prohibit people with a seizure disorder from driving until they have been free of seizures for at least 6 months to 1 year.

A family member or close friend should be trained to help if a seizure occurs. Attempting to put an object (such as a spoon) in the person's mouth to protect the person's tongue should not be tried, because such efforts can do more harm than good. The teeth may be damaged, or the person may bite the helper unintentionally as the jaw muscles contract. The important steps are protecting the person from falling, loosening clothing around the neck, and placing a pillow under the head. People who lose consciousness should be rolled onto one side to ease breathing. People who have had a seizure should not be left alone until they have awakened completely and can move about normally. Usually, their doctor should be notified.

If all drugs are ineffective in controlling seizures or if side effects of the drug cannot be tolerated, brain surgery is a possibility. If a defect in the brain (such as a scar) can be identified as the cause and is confined to a small area, surgically removing that area may eliminate the seizures or reduce their severity and frequency. Surgically cutting the nerve fibers that connect the two sides of the brain (corpus callosum) may help people who have seizures that originate in several areas of the brain or that spread to all parts of the brain very quickly. This procedure usually has no appreciable side effects. After surgery, many people need to continue to take anticonvulsants.

Electrical stimulation of the vagus nerve (cranial nerve X) can reduce the number of partial seizures by one third. The vagus nerve is thought to have indirect connections to areas of the brain often involved in producing seizures. A device that looks like a heart pacemaker is implanted under the left collarbone and is connected to the vagus nerve in the neck with a wire that runs under the skin. The device causes a small bulge under the skin. The operation is performed on an outpatient basis and takes about 1 to 2 hours. When people who have such a device sense that a seizure is about to begin, they turn the device on with a magnet. Or, the device may be left on all the time. For some people, vagus nerve stimulation prevents seizures or reduces their frequency and severity. Vagus nerve stimulation is used in addition to anticonvulsants. Side effects include hoarseness, cough, and deepening of the voice.
....referenced, Merck

Learn More About Seizures and Syndromes
For more on seizures and syndromes, visit the page on Seizures and Epilepsy at the Web site of the National Institute of Neurological Disorders and Stroke (NINDS) or the Epilepsy Foundation’s Answer Place.