Epilepsy and Seizures

An absence seizure causes a short period of “blanking out” or staring into space. Like other kinds of seizures, absence seizures are caused by abnormal activity in a person’s brain. 

Some people call absence seizures “petit mal seizures,” although that name is not common anymore.

There are two types of absence seizures:

• Simple absence seizures: During a simple absence seizure, a child usually stares into space for less than 10 seconds. Because they happen so quickly, it’s very easy not to notice simple absence seizures. It’s also common to confuse them with daydreaming or not paying attention.
• Complex absence seizures: During a complex absence seizure, a child will make some kind of movement in addition to staring into space. Movements might include blinking, chewing or hand gestures. A complex absence seizure can last up to 20 seconds.
   

During an atypical absence seizure, a child will stare (as they would in any absence seizure). However, they might also be somewhat responsive. Eye blinking or slight jerking movements of the lips might occur. 

This behavior can be hard to separate from the person’s usual behavior, especially for children who have cognitive impairment. Unlike other absence seizures, atypical absence seizures usually cannot be produced by rapid breathing. They usually last between five and 30 seconds (commonly more than 10), with a gradual beginning and ending.

In an atonic seizure, muscles suddenly lose strength. The eyelids might droop, the head might nod, and a child might drop things and fall to the ground. Atonic seizures are also called “drop attacks,” “drop seizures” or “akinetic seizures.” 

During an atonic seizure, a child usually remains conscious. The seizure typically lasts less than 15 seconds. Atonic seizures often start in childhood, and last into adulthood. Many people with atonic seizures injure themselves when they fall, so they might choose to use protection such as a helmet.

In a clonic seizure, muscles rapidly contract and relax, creating a jerking motion that cannot be stopped by restraining or repositioning the arms or legs. Clonic seizures are rare. Brief and infrequent clonic seizures in infants usually disappear on their own within a short time. Other types might need prolonged treatment.

Myoclonic seizures are brief, shock-like jerks of a muscle or a group of muscles. They don’t usually last more than a second or two. Sometimes many myoclonic seizures will occur within a short period of time.

In a tonic seizure, muscle tone greatly increases, causing the body, arms, or legs to make sudden stiffening movements. A child having a tonic seizure usually stays conscious during the seizure, which typically lasts less than 20 seconds.

Tonic seizures most often occur during sleep and usually involve all or most of the brain, affecting both sides of the body. A child standing up when the seizure starts will often fall. 

Tonic-clonic seizures are what most people think of when they hear the word “seizure.” (An older term for this type is “grand mal seizure.”) Tonic-clonic seizures combine the characteristics of tonic seizures and clonic seizures. 

The tonic phase comes first: 

1. All the muscles stiffen. 
2. Air forced past the vocal cords causes a cry or groan. 
3. The child loses consciousness and falls to the floor. 
4. The child might bite their tongue or cheek, causing bloody saliva to come from the mouth. 
5. The child might turn a bit blue in the face.

After the tonic phase comes the clonic phase: 

1. The arms and usually the legs begin to jerk rapidly and rhythmically, bending and relaxing at the elbows, hips and knees. 
2. After a few minutes, the jerking slows and stops. 
3. The child sometimes loses bladder or bowel control as the body relaxes. 
4. Consciousness returns slowly, and the person might feel drowsy, confused, agitated or depressed.

Tonic-clonic seizures generally last one to three minutes. A tonic-clonic seizure that lasts longer than five minutes needs medical help. A seizure lasting more than 10 minutes, or three seizures without a normal period in between, indicates a dangerous condition called convulsive status epilepticus. This requires emergency treatment.

Focal seizures are characterized according to one or more of the following features.
 
Motor seizures cause a change in muscle activity. For example, a child might have atypical movements, such as jerking of a finger or stiffening of part of the body. The movements might spread, either staying on one side of the body or extending to both sides. Other examples include weakness, which can even affect speech, and coordinated actions such as laughter or automatic hand movements. 

A child experiencing a sensory seizure or aura  might:

• Smell or taste things that aren’t there (clicking, ringing, or a person’s voice when there is no actual sound).
• Feel a sensation of “pins and needles” or numbness. 
• Feel as if they are floating or spinning in space. 
• Have visual hallucinations or experience illusions. 

Autonomic seizures cause changes in the part of the nervous system that automatically controls bodily functions. Symptoms of autonomic seizures might include:

• Strange or unpleasant sensations in the stomach, chest or head.
• Changes in the heart rate or breathing.
• Sweating.
• Goose bumps.

Dyscognitive seizures change how kids think, feel or experience things. Sometimes a child’s awareness might be altered.

The child might:

• Have problems with memory, garbled speech, inability to find the right word, or trouble understanding spoken or written language. 
• Suddenly feel emotions like fear, depression, or happiness with no outside reason. 
• Feel as though they are outside their body.
• Have feelings of déjà vu (“I’ve been here before”) or jamais vu (“This is new to me”—even though the setting is familiar).

Seizures usually start in a focal area of the brain. They quickly involve other areas of the brain that affect alertness and awareness. So even though a child’s eyes are open and they might make movements that seem to have a purpose, in reality they’re unaware of their actions. If the symptoms are subtle, other people might think the person is just daydreaming.

Some kids can have focal seizures without realizing anything has happened. The seizure can wipe out memories of events just before or after it occurs. 

Some focal seizures turn into bilateral convulsive seizures. They usually last between 30 seconds and two minutes. Afterward, the child might be tired or confused for several minutes and might not return to normal function for hours.

Bilateral convulsive seizures start in one side of the brain (focal) and spread to both sides of the brain (become generalized) after the initial event has begun, spreading throughout the brain. 

Secondarily bilateral convulsive seizures occur in more than 30% of people who have focal epilepsy.

Children ages 3 months to 5 or 6 years might have tonic-clonic seizures when they have a high fever. These “febrile seizures” occur in 2 to 5% of all children. 

There is a slight tendency for febrile seizures to run in families. If a child’s parents, brothers or sisters, or other close relatives have had febrile seizures, the child is a bit more likely to have them. Sometimes, however, the seizure comes without a family history. A fever might begin in a previously healthy child, with the seizure being the first sign that the child is ill.

A nonepileptic seizure is an event that looks like an epileptic seizure, but does not have an epileptic cause. 

A common type of nonepileptic seizure is described as psychogenic (beginning in the mind). Psychogenic events are caused by subconscious thoughts, emotions or stress, not by atypical electrical activity in the brain. While doctors consider these seizures psychological in nature, they do not consider them purposely produced. Usually the child believes their seizures to be epileptic in nature.

Some nonepileptic seizures could be caused by other physical problems. Further testing is needed to find the exact cause, so they can be treated properly.

Sometimes seizures cannot be controlled with seizure medicines. These seizures might be referred to as: “uncontrolled,” “intractable,” “refractory,” or “drug resistant.” 

According to the International League Against Epilepsy (ILAE), drug-resistant epilepsy occurs when a person has failed to become and stay seizure-free with adequate trials of two seizure medicines (called AEDs).