Types of seizures
There are many different types of seizures. People may be diagnosed 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.Before discussing the right kind of treatment, a doctor will figure out what type (or types) of seizures you might have.
Seizures are usually divided into two major groups:
- Generalized Seizures (absence, atonic, tonic-clonic, myoclonic). These seizures begin with a widespread electrical discharge that involved both sides of the brain at once.
- Partial Seizures (simple and complex): These seizures start with an electrical discharge in one area of the brain.
Below we’ll talk about these types in detail. If you’d like to learn more about seizures, feel free to contact us so we can discuss further.
An absence seizure causes a short impairment of consciousness, usually lasting no more than a few seconds. In other words, it’s a period of “blanking out” or staring off into space. Just like other seizures, it’s caused by abnormal activity in the brain. Sometimes this is referred to as a ‘Petit Mal’ seizure, although this term is becoming less common. Absence seizures can also happen with other types of seizures. These seizures happen so often and are so quick they often go unnoticed, even if the person has 50-100 occurrences a day. Absense seizures can also occur occasionally, once or twice a day.
There are two types of absence seizures:
- Simple Absence Seizures: With this type, a person will usually stare into space for about 10 seconds. Because they happen so fast it’s easy to miss when they occur or confuse them with daydreaming/not paying attention. They may occasionally has brief myoclonic jerking of the eyelids or facial muscles or result in loss of muscle tone (See our section on Atonic absence seizures)
- Complex Absence Seizures: For this type, in addition to staring into space a person will also make a movement. This could be blinking, chewing, or hand gestures. These seizures can last up to 20 seconds. Actions like moving your moth, picking at the air or clothing are referred to as “automatisms”
Doctors will usually order a test, called an EEG (electroencephalogram), to check the brain for electrical activity that can cause seizures. If they think someone may be having absence seizures, doctors might also ask the person to breathe very quickly. This will often trigger (cause) seizures in people who get them.
It’s very important that people who have absence seizures get the right diagnosis from a doctor, because absences seizures are often confused with other kinds of seizures — especially complex partial seizures.
Absence seizures are most common in children ages 4 to 14, but it’s also possible for teens and adults to have them as well. They rarely begin after age 20, but it does happen. Because absence seizures are so easy to misunderstand, it’s very important that children in school receive effective treatment as the seizures can interfere with learning. A child with absence seizures may miss important instructions or lessons in class. Likewise, it’s important to educate the child’s teachers about absence seizures so that it doesn’t seem like the child is day-dreaming or not paying attention in class. Most kids with typical absence seizures can otherwise live life normally. About half the children also have infrequent generalized tonic-clonic seizures.
For 7 out of 10 kids with absence seizures, they will stop having them by age 18. Kids who start having absence seizures before age 9 are much more likely to outgrow them than children whose seizures start after age 10.
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.
Atonic (also called a drop attack):
Atonic seizures cause loss of muscle tone. In fact, Atonic literally means “without tone” so the muscles become weak. It may cause the eyelids to droop, the head to drop, a person may drop things or fall to the ground. Usually, the person will remain conscious. In some children, only their head suddenly drops. After a few seconds to a minute the child recovers, regains consciousness. These seizures usually last less than 15 seconds. 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. After the seizure the person may be confused or injured from a fall. If they sustain injuries seek medical attention.
Generalized Tonic-Clonic Seizures
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). These seizures combine the characteristics of tonic seizures and clonic seizures.
Tonic-Clonic seizures affect both kids and adults. For children who have had a single tonic-clonic seizure, the risk that they will have more seizures depends. 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
Let’s break down these seizures into the two different stages:
- Tonic Seizure: During this phase, the muscle tone is increased greatly in the body, arms or legs causing sudden stiffening movements. Breathing may decrease or cease altogether, producing cyanosis (turning blue) of the lips, nail beds, and face. Because air is being forced past the vocal chords you may hear a cry or groan.
- Clonic Seizure: During this seizure there is rapid contraction and relaxation of the muscle. In other words, repeated jerking. Breathing typically returns during the clonic (jerking) phase, but it may be irregular. This clonic phase usually lasts less than a minute.
These seizures will generally last 1 to 3 minutes. If a tonic-clonic seizure lasts longer than 5 minutes requires medical attention. A seizure that lasts longer than 10 minutes, or three seizures without a normal period in between indicates a dangerous condition called convulsive status epilepticus. This requires emergency treatment.
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. Clonic seizures on their own are rare and are most commonly seen in tonic-clonic seizures.
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 person will be tired, possibly confused and want to sleep. Headaches sometimes occur. Full recovery takes minutes to hours, depending on the individual.
Diagnosing a Tonic-Clonic Seizure:
The typical appearance of a tonic-clonic seizure is usually easy to recognize. The doctor will want a detailed description of the seizures. An EEG and other tests may help to confirm the diagnosis or suggest a cause.
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 (MY-o-KLON-ik) are rapid, brief shock-like jerks of muscles, usually occurring 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. There can be just one but sometimes many can happen within a short period of time.
Even people without epilepsy can experience myoclonus in hiccups or in a sudden jerk that may wake you up as you’re just falling asleep. These things are normal.
Simple Partial Seizures
People who have simple partial seizures do not lose consciousness. 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 partial seizures can affect movement, emotion, sensations and feelings in unusual and sometimes even frightening ways. These seizures are usually brief lasting less than 2 minutes.
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 Partial 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, 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).
First Aid for Simple Partial Seizures:
No first aid necessary unless seizure becomes convulsive, then follow first aid for Tonic-Clonic seizures or Complex Partial seizures. When a simple partial seizure ends, the person can often go back to doing whatever they were doing before it started.
Complex Partial Seizures:
Complex partial seizures (psychomotor seizures) are called “complex” because they impair consciousness and “partial” because they begin in a limited area of the brain. They usually start in a small part of the temporal or frontal lobe and move to other areas of the brain that affect alertness and awareness. So during a complex partial seizure, for example, a person’s eyes may be open and they may be moving but in reality “nobody’s home.”
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 partial seizures are the most common type of seizure experienced by people with epilepsy. Anyone can get them, but they may be more likely in people who have had a head injury, brain infection, stroke or a brain tumor. However often the cause is unknown.
Complex Partial 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.
Complex partial seizures can turn into a secondarily generalized seizure lasting between 30 seconds and two minutes. Afterward the person may be tired or confused for about 15 minutes and may not be able to return to normal functioning for several hours.
First Aid for Complex Partial 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. As such you may hear someone refer to them as an event rather than a seizure. They are considered to be psychological rather than the result of a physical cause and are often a challenge to diagnose and treat. This is described as psychogenic, meaning it begins in the mind. It does not mean that the person is causing them on purpose. 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.