8 TYPES OF SEIZURES AND THEIR CHARACTERISTICS - NEUROPSYCHOLOGY - 2025

The main types of seizures are generalized and focal. Depending on the area of ​​the brain that is affected, the presence of one type or another will be determined. A seizure is based on an abnormal electrical discharge from the brain that can cause you to pass out, lose consciousness, and perform involuntary and uncontrolled motor movements (spasms).

However, not all seizures are the same, as there are several types of seizures depending on the brain involvement that occurs.

The term seizure or seizure refers to a sudden or sudden brain dysfunction that causes the person to collapse, have seizures, or have other behavioral abnormalities temporarily.

From a medical point of view, the seizure is simply a transient symptom characterized by neural activity in the brain that leads to peculiar physical findings such as repeated and trembling contraction and distension of one or more sudden muscles.

Likewise, seizures can cause alterations in the mental state of the person and psychiatric disorders such as dejà vu or jamais vu.

Today it is known that most seizures are caused by electric shocks that occur in the brain or fainting, that is, by a reduction in the cerebral blood supply.

Types of seizures and their characteristics

In general, there are two main types of seizures, however, we will see how many different subtypes can be witnessed in each type of seizure.

- Generalized crisis

These types of seizures are those that are caused by abnormal activity of neurons on both sides of the brain. As the name suggests, in generalized seizures, the entire brain is affected by abnormal electrical shocks.

By affecting the entire brain, these types of seizures are considered more severe than those that are not generalized. Likewise, the famous symptoms such as fainting, loss of consciousness or the presence of muscle spasms are usually prototypical of this type of seizure.

When we talk about generalized seizure, we are most likely talking about that more popularly known type of seizure. However, despite the fact that these types of seizures are the ones that most frequently produce muscle spasms, not all types of generalized seizures have them.

And it is that among generalized seizures, we find different subtypes of seizures, each of them with certain characteristics.

In fact, among these types of seizures we can find "convulsive" crises, that is, with the presence of involuntary and generalized motor movements, and "non-convulsive" crises, in which this type of muscle spasms do not occur.

Seizure with no seizure

This type of crisis is characterized by the absence of seizure, that is, when the person suffers this type of crisis, it does not manifest the typical muscle spasms. This type of seizure belongs to generalized seizures, which is why it is characterized by the presence of abnormal activity in neurons on both sides of the brain.

Normally the condition of this type of crisis, despite not involving the presence of muscle spasms and being visually less aggressive, is usually serious. The person suffering from it may appear to be staring into space or have mild tremors in their muscles.

However, they are considered "petty evil" seizures and the person with them keeps their gaze fixed for a few seconds and then returns to full function.

After suffering this crisis, the individual does not remember what happened during the seizure. However, the typical postictal period (after the seizure) that we will see does not usually occur in the vast majority of other types of seizures.

Myoclonic crisis

In this type of generalized crisis, muscle spasm or contractions do occur. It is characterized mainly by the presence of rapid jerks of muscles in the body, especially those of the arms and legs, and by loss of consciousness.

Myoclinical seizures can be caused by different pathologies.

One cause of myoclinical crisis classifies the seizure as benign or non-epileptic and produces very mild shaking, similar to those that people have when we sleep.

The other causes of this type of seizure are epileptic. Among them we can find one that is exclusive to childhood, benign myoclinical epilepsy. It consists of a strange disorder, which occurs in few cases and which begins between 4 and two years of life.

The other two causes of myoclinical seizure are severe myoclinical epilepsy, which consists of a disorder that causes chronic and progressive brain damage, and Lenox-Glastaut syndrome, a severe neurological disorder associated with the absence of spike waves. on EEG and mental retardation.

Tonic crisis

These types of seizures cause extreme stiffness of the muscles in the body, usually the back, legs, and arms.

Like the rest, they are explained by abnormal electrical discharges in the brain and cause fainting and loss of consciousness in most cases.

Clone crisis

Like the previous one, there are muscular alterations but they are differentiated by the presence of repeated spasmodic movements in the muscles on both sides of the body instead of extreme muscular rigidity.

This type of crisis could be associated with the popularly known seizure in which the person "convulses" through sudden muscle movements and constant spasms.

Tonic-clonic crisis

These types of seizures present a mixture of symptoms of tonic seizures and clonic seizures. The person may have a stiff body, repeated pulling on the limbs, and total loss of consciousness.

These types of seizures are considered "grand mal" seizures and are interpreted as the most serious of all types of generalized seizures.

Atonic crisis

The latter type of generalized seizures are characterized by a total loss of muscle tone.

The person affected by this type of seizure will fall or drop his head involuntarily and will collapse as he loses his muscle tone in practically the entire body.

-Focal onset crisis

Unlike generalized seizures, this type of seizure is characterized by affecting only a particular region of the brain.

The abnormal electrical discharges that characterize seizures, in this case, only affect a small part of the brain, so the rest of the neural structures are not affected by the seizure.

This type of crisis is considered less serious than the previous ones but much more prevalent in society. In fact, it is estimated that around 60% of people with epilepsy suffer from focal seizures rather than generalized seizures.

Likewise, this type of seizure does not usually affect the consciousness of the person, so when an individual suffers a focal crisis, despite being able to slightly lose his state of consciousness, he will rarely faint or be totally unconscious.

Likewise, the typical muscular symptoms through spasms and rapid and aggressive jerks in different regions of the body, are not seen in focal onset seizures either.

Focal seizures refer to this type of seizure that can be practically asymptomatic in some cases and that are much less noticeable and shocking than generalized seizures.

In general, although seizures can be classified according to the brain region they affect, they are subdivided into two main categories:

Simple focal seizures

Faced with this type of seizure, the person remains conscious and does not faint or lose consciousness at any time. However, you may experience unusual or strange feelings, sensations or experiences.

In the presence of the crisis, that is, an abnormal electrical activity in a specific region of the brain, the individual may have sudden and inexplicable feelings of joy, anger or sadness.

Likewise, you may also have symptoms such as nausea or vomiting and have strange sensitive experiences such as hearing, smelling, seeing or feeling things that are not real.

Complex focal seizures

This type of seizure differs from the previous one mainly by the affectation of consciousness. While in simple crises the person remains conscious, in this type of seizure the individual has a slight loss of consciousness.

It is usually common for the person suffering from a complex crisis to report a dreamy or strange experience, of which they do not remember anything clearly.

During the crisis the person may perform strange behaviors such as repetitive movements of the eyelids, motor tics, strange movements with the mouth or even changes in gait, but will not present the muscle spasms typical of generalized attacks.

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