Types of Seizures
There are many different types of seizures. People may experience just one type or more than one. The kind of seizure a person has depends on which part and how much of the brain is affected by the electrical disturbance that produces seizures. Experts divide seizures into generalized seizures (absence, atonic, tonic-clonic, myoclonic), partial (simple and complex) seizures, non-epileptic seizures, infantile spasms and status epilepticus.
View Kelly Caravetta, CRNP, Powerpoint on Seizure Classification:
More common in children than in adults, absence seizures almost always start between ages 4 and 12 years. Although absence seizures rarely begin after age 20,it is possible for them to occur at any age. Absence seizures are characterized by a brief impairment of consciousness, which usually lasts no more than a few seconds. The person, whether sitting or standing, simply stares vacantly; neither speaking nor apparently hearing what is said. Then, as abruptly as it began, the impairment lifts and the person continues with his or her previous activity. The seizure is usually associated with some degree of altered awareness . Automatisms may occur in prolonged absence seizures. Absence seizures are frequently so brief that they escape detection, even if the person is experiencing 50 to 100 episodes daily. They may occur for several months or even years before that person is sent for a medical evaluation.
Although manifestations of their seizures are usually subtle, children with absence seizures need prompt and effective treatment because their seizures can interfere with learning. They also interfere with attention and full consciousness.
Absence Seizure Characteristics:
- No aura
- Abrupt onset
- Brief duration
- Prompt recovery
Some absence seizures are accompanied by brief myoclonic jerking of the eyelids or facial muscles, or by variable loss of muscle tone. More prolonged episodes may be accompanied by automatisms, which may lead them to be confused with complex partial seizures. However, complex partial seizures last longer, may begin with an aura and are usually marked by some type of confusion following the seizure.
Absence seizures may occur only occasionally or more than 100 times a day. Most children with typical absence seizures are otherwise normal. About half the children also have infrequent generalized tonic-clonic seizures. The electroencephalographic (EEG) pattern of diffuse spike-wave is closely correlated with absence seizures.
EEG showing generalized 3Hz (this means within a one-second period there are approximately three epilepsy waves) spike and wave discharges in a patient having an absence seizure.
Absence seizures are often confused with complex partial seizures. This is an important distinction because the drugs that prevent absence seizures have little or no effect on complex partial seizures. Conversely, the most effective drugs for complex partial seizures are either ineffective against or increase the frequency of absence seizures.
First Aid for an Absence Seizure:
No immediate first aid is usually necessary, but a medical evaluation is indicated to try to prevent these seizures from recurring. If this is the first observation of an absence seizure, medical evaluation is recommended. Absence seizures (e.g. a seizure common to petit mal epilepsy) are lapses of awareness, sometimes with staring, that begin and end abruptly, lasting only a few seconds. There is no warning and no after-effect.
Atonic (also called a drop attack):
Atonic seizures produce an abrupt loss of muscle tone. Other names for this type of seizure include drop attacks, astatic or akinetic seizures. They produce head drops, loss of posture, or sudden collapse. In some children, only their head suddenly drops. After a few seconds to a minute the child recovers, regains consciousness. Because atonic seizures are so abrupt, without any warning, and because the people who experience them fall with force, atonic seizures can result in injuries to the head and face.
Protective headgear is sometimes used by children and adults; the seizures tend to be resistant to drug therapy.
First Aid for an Atonic Seizure:
No first aid is needed (unless there is injury from the fall), but if this is a first atonic seizure, the child should be given a thorough medical evaluation.
Generalized Tonic-Clonic Seizures (also called grand mal or a convulsion):
This type is what most people think of when they hear the word “seizure.” An older term for them is “grand mal.” They begin with stiffening of the limbs (the tonic phase), followed by jerking of the limbs and face (the clonic phase). As implied by the name, they combine the characteristics of tonic seizures and clonic seizures.
For children who have had a single tonic-clonic seizure, the risk that they will have more seizures depends on many factors. Some children will outgrow their epilepsy. Often, tonic-clonic seizures can be controlled by seizure medicines. Many patients who are seizure-free for a year or two while taking seizure medicine will stay seizure-free if the medicine is gradually stopped.
Contrary to popular belief, nothing should be placed in the mouth during the seizure. Severe injury could occur.
Generalized Tonic-Clonic Seizure Characteristics:
During the tonic phase, breathing may decrease or cease altogether, producing cyanosis (turning blue) of the lips, nail beds, and face. Breathing typically returns during the clonic (jerking) phase, but it may be irregular. This clonic phase usually lasts less than a minute.
Some people experience only the tonic, or stiffening phase of the seizure; others exhibit only the clonic or jerking movements; still others may have a tonic-clonic-tonic pattern.
Incontinence may occur as a result of the seizure. The tongue or inside of the mouth may be bitten during the episode; breathing afterwards may be noisy and appear to be labored. Turning the patient on one side will help prevent choking and keep the airway clear.
Following the seizure, the patient will be lethargic, possibly confused and want to sleep. Headaches sometimes occur. Full recovery takes minutes to hours, depending on the individual.
First Aid for Generalized Tonic-Clonic Seizures:
- Prevent further injury. Place something soft under the head, loosen tight clothing and clear the area of sharp or hard objects.
- Do not force objects into the person’s mouth.
- Do not restrain the person’s movements, unless they place him or her in danger.
- Turn the person on his or her side to open the airway and allow secretions to drain.
- Stay with the person until the seizure ends.
- Do not pour any liquids into the person’s mouth or offer any food, drink or medication until he or she is fully awake.
- If the person does not resume breathing after the seizure, start cardiopulmonary resuscitation (CPR).
- Let the person rest until he or she is fully awake.
- Be reassuring and supportive when consciousness returns.
- A convulsive seizure is usually not a medical emergency unless it lasts longer than five minutes, or a second seizure occurs soon after the first, or the person is pregnant, injured, diabetic or not breathing easily. In these situations the person should be taken to an emergency medical facility.
Myoclonic seizures are rapid, brief contractions of bodily muscles, which usually occur at the same time on both sides of the body. Occasionally, they involve one arm or a foot. People usually think of them as sudden jerks or clumsiness. A variant of the experience, common to many people who do not have epilepsy, is the sudden jerk of a foot during sleep.
Sudden, brief, involuntary muscle jerks, a bit like the kind everyone has when a foot or leg suddenly jerks in bed. May be mild and affect only part of the body, or be strong enough to throw the child abruptly to the floor. May occur as a single seizure or a cluster of seizures.
First Aid for a Myoclonic Seizure:
First aid is usually not needed. However, a person having a myoclonic seizure for the first time should receive a thorough medical evaluation.
Focal (Partial) Seizures
However, some people, although fully aware of what’s going on, find they can’t speak or move until the seizure is over. They remain awake and aware throughout. Sometimes they can talk quite normally to other people during the seizure. And they can usually remember exactly what happened to them while it was going on. However, simple focal seizures can affect movement, emotion, sensations and feelings in unusual and sometimes even frightening ways.
Sometimes the seizure activity spreads to other parts of the brain, so another type of seizure follows the simple focal seizure. This can be a complex partial seizure or a secondarily generalized seizure.
Simple Focal Seizure Characteristics:
Doctors often divide simple focal seizures into categories depending on the type of symptoms the person experiences:
Motor Seizures – These cause a change in muscle activity. For example, a person may have abnormal movements such as jerking of a finger or stiffening of part of the body. These movements may spread, either staying on one side of the body (opposite the affected area of the brain) or extending to both sides. Other examples are weakness, which can even affect speech, and coordinated actions such as laughter or automatic hand movements. The person may or may not be aware of these movements.
Sensory Seizures - These cause changes in any one of the senses. People with sensory seizures may smell or taste things that aren’t there; hear clicking, ringing, or a person’s voice when there is no actual sound; or feel a sensation of “pins and needles” or numbness. Seizures may even be painful for some patients. They may feel as if they are floating or spinning in space. They may have visual hallucinations, seeing things that aren’t there (a spot of light, a scene with people). They also may experience illusions—distortions of true sensations. For instance, they may believe that a parked car is moving farther away, or that a person’s voice is muffled when it’s actually clear.
Autonomic Seizures – These cause changes in the part of the nervous system that automatically controls bodily functions. These common seizures may include strange or unpleasant sensations in the stomach, chest, or head; changes in the heart rate or breathing; sweating; or goose bumps.
Psychic Seizures – These seizures change how people think, feel, or experience things. They may have problems with memory, garbled speech, an inability to find the right word, or trouble understanding spoken or written language. They may suddenly feel emotions like fear, depression, or happiness with no outside reason. Some may feel as though they are outside their body or may have feelings of déja vu (“I’ve been through this before”) or jamais vu (“This is new to me”— even though the setting is really familiar).
Complex Focal Seizures:
Complex focal seizures (psychomotor seizures) are called “complex” because they impair consciousness and “focal” because they begin in a limited area of the brain. Most complex partial seizures are associated with some automatic behaviors, termed automatisms.
The greatest danger of an unexpected seizure occurs when the person is driving a car or operating dangerous equipment. Those with seizures that impair consciousness or control of movement should avoid these activities as directed by their physician or state driving laws. In some cases, potentially dangerous equipment can be used safely if adequate precautions are taken.
Complex Focal Seizure Characteristics:
During a complex focal seizure, the person usually becomes motionless and stares or makes automatic movements such as fumbling movements of the hands. Other behaviors during complex partial seizures may cause concern, but are not dangerous to the patient or other people. These include screaming, kicking, ripping up papers, disrobing, If someone is known to have unusual automatisms, he or she should be led in a quiet and reassuring manner-not forcibly-out of public places, such as an office or store.
First Aid for Complex Focal Seizures:
When someone has a complex focal seizure, speak quietly and in a reassuring manner, because some persons have only partial impairment of consciousness and can react to emotional or physical stimulation. Do not yell at the person, or restrain him or her unless absolutely necessary, which is rare. The most important aspect of first aid during a complex partial seizure is to keep the person safe from harm.
If the seizure is prolonged (more than 5 to 10 minutes of impaired consciousness with automatisms), or if there are two or more complex focal seizures without return of consciousness between seizures, then
medical help should be sought.
Infantile Spasms (IS) is a rare form of epilepsy that typically begin in the first 4- 8 months of life and is characterized by a flexion (bending and jerking) of the trunk or extremities (arms and legs), and is often mistaken for colic. An episode can range from a subtle head jerk to a flexion that lasts for a few seconds and most often occurs in clusters.
Infantile spasms is typically diagnosed by observing spasms in a child in infancy who also displays specific patterns in their EEG. This pattern is called hypsarrhythmia
(hips-A-‘rith-mE-uh) and there is a strong correlation between hypsarrhythmia and the cogitative impairment and developmental delays that are often associated with IS.
There is not much known about what triggers infantile spasms, much more scientific research is needed. In about 70% of cases, the cause of IS can be linked to a central nervous system (CNS) infection, brain development abnormalities or genetic abnormalities. These are called “symptomatic” causes of IS because they have a cause of origin and can impact the course of treatment selected, which can ultimately affect a child’s outcome.
In approximately 30% of cases, there is no known cause for IS, this is characterized as “cryptogenic”.
While Infantile Spasms are a rare form of epilepsy, it can be identified by distinct characteristics if physician and caregivers are aware of the distinct symptoms.
For more information: www.infantilespasmsinfo.org
Non-epileptic seizures are episodes that briefly change a person’s behavior and may look like epileptic seizures.
Non-epileptic seizures (also referred to as pseudoseizures, psychogenic or cryptogenic seizures) are episodic, paroxysmal events not related to abnormal electrical activity in the brain. Considered to be of psychological rather than physical origin, they offer a major challenge to diagnosis and treatment. In one study, fully 25 percent of patients referred to an epilepsy center to be evaluated for surgery had non-epileptic seizures.
A person having non-epileptic seizures may have internal sensations that resemble those felt during an epileptic seizure. The difference in these two kinds of episodes is often hard to recognize by just watching the event, even by trained medical personnel.
The episodes resemble true epileptic seizures in many ways. But there is an important difference. They have characteristics which differ from true seizures in important points, including repeatedly normal EEG readings between seizures; lack of any response to therapeutic levels of anti-epileptic drugs; and violent thrashing of all four limbs, especially if not synchronous, during an episode. Epileptic seizures are caused by abnormal electrical changes in the brain and, in particular, in its outer layer, called the cortex. Non-epileptic seizures are not caused by electrical disruptions in the brain.
Non-epileptic seizures tend to be pleomorphic over time (changing in character) and longer than epileptic seizures. Non-epileptic seizures also occur only in wakefulness, whereas epileptic seizures occur in wake and sleep. Anti-epileptic drugs do not stop non-epileptic seizures.
Prolonged or clustered seizures sometimes develop into non-stop seizures, a condition called status epilepticus.
Status epilepticus is a medical emergency. It requires hospital treatment to bring the seizures under control. If someone has had episodes of non-stop seizures that had to be treated in the emergency room, you will want to have a plan of action ready in case they occur again.
Managing Status Epilepticus
- Ask the doctor if there are any new treatments you can use at home or school to stop a seizure from developing into status epilepticus.
- Call an ambulance. Do not attempt to transport an actively seizuring person in your car unless an ambulance is not available.
- Be aware of where the nearest hospital is, how long it takes to get there. If you live a long way from the hospital, you may plan to call earlier than you would if it were closer. If there are several hospitals nearby, ask your doctor in advance which one to call.
- Consider arranging for standing orders prepared by the doctor to be kept in the emergency room so the seizure can be managed as your doctor directs. Ask for a copy for yourself if you travel out of town.
- Leave detailed written instructions with babysitters or adult caregivers. If you have been instructed in the use of in-home therapy, make sure that a responsible caregiver also receives instruction.
- Fortunately, most seizures, even those that are prolonged, end without injury. The important thing is to work with your doctor so that you have a plan to follow when they occur.
Managing Prolonged Seizures in Children
Unless your doctor has advised otherwise, a seizure in a child with epilepsy that ends after a couple of minutes does not usually require a trip to the emergency room.
However, if it lasts more than 5 minutes without any sign of slowing down, is unusual in some way, or if a child has trouble breathing afterwards, appears to be injured or in pain, or recovery is different from usual, call 911 for emergency help.
It is always good to talk to your doctor in advance and plan on what to do if your child has a prolonged seizure so you can have an emergency plan.
Some people have convulsive seizures that are prolonged— several minutes—or seizures that sometimes occur in clusters.
New treatments are available that parents or caregivers can administer orally, rectally or by injection to bring this type of seizure to an end. Ask your doctor whether these treatments may be appropriate for you.
Seizures that produce body jerking, staring spells or a state of confusion can also occur in clusters and fail to stop in the usual way.