Types of seizures: why do they occur and what are the causes?

When you think of neurological disorders like epilepsy, the first image that comes to mind in most people is that of a person suffering from seizures, sudden violent contractions all over the body that get them out of bed. . from a hospital or on land.

Indeed, seizures are one of the most visible and important symptoms of epilepsy (In fact his diagnosis is made among other things if the subject has had several seizures). But not all seizures are the same and do not occur only in epilepsy. In this article, we are going to visualize the different types of seizures.

The crisis: a brief definition of the term

Seizures are those spasmodic movements of voluntary skeletal muscles that occur abruptly, rhythmically, repeatedly, and completely involuntarily, with violent contractions of one or more muscle groups.

Seizures are a symptom of a brain problem that can have multiple origins. They are usually short-lived (usually up to two minutes), although longer episodes can be dangerous and are treated as an emergency. Its main cause is the existence of electrochemical imbalances in the brain, or the hyperexcitability of specific neuronal groups.

Types of seizures

As noted above, not all seizures are the same, but different types can be established depending on the area (s) of the brain affected, the level of muscle contraction, or the causes of the seizure.

1. Classification according to the affected areas of the brain

Depending on whether the seizures are due to alteration in a specific area of ​​the brain or in generalWe can consider the existence of two major groups of crises.

1.1. Focal-onset seizures or partial seizures

These are seizures due to the alteration of one or more well-defined regions of the brain. The affected area will mark the type of symptoms to be felt. Motor convulsion occurs in a specific part of the body, or even in a hemisphere (that is, on one side of the body).

They can be simple and complex, depending on whether or not there are alterations in consciousness (the latter being complex). There may be sensory disturbances and actions and gestures of perseverance, And can even serve as a warning of the onset of future generalized seizures. It is also common for a focal seizure to generalize by activating certain areas of the brain first and then spreading to the rest of the brain, these seizures being referred to as generalized secondary.

1.2. Generalized crises

Generalized seizures are those in which all or part of the brain is present, with electrical disturbances appearing in both hemispheres. They usually cause loss of consciousness and tonic-clonic seizures appear. They occur suddenly, although they may be preceded by an aura, and cause the patient to fall. It is common for sphincters to lose control, tongue bites and even twists and injuries to muscle groups.

Within this subgroup they can find absence seizures (in which there may be slight contractions), myoclonic, tonic-clonic (being the most representative) or even atonic in which a convulsion does not occur. not appear otherwise loss of muscle tone after a contraction.

2. Depending on the level of muscle contraction

Another classification could be made depending on the intensity level or the characteristics of the crisis itself. These include the following.

2.1. tonic seizures

It is a type of seizure in which there is a strong muscle contraction of one of the muscles or of one or more muscle groups. There is a high level of stiffness in the affected muscle or muscles.

2.2. clonic seizures

Clonic seizures are those that occur repeatedly every two or three seconds, of short intensity and power.

2.3. myoclonic seizures

Like the clones, they are small muscle spasms of minimal duration, but which result in the involuntary movement of a part of the body.

2.4. Tonic-clonic seizures

Tonic-clonic seizures are the most prototypical types of seizures, with tonic and clonic seizures occurring at the same time. This is the type of seizure that is part of the large injury seizure.

2.5. atonic crises

In this type of seizure, there are no real convulsions, but the sudden disappearance of muscle tone. This disappearance is sometimes preceded by a powerful muscle spasm.

3. Depending on the cause of the seizures

Seizures can be caused by very different causes. It is important not to identify epileptic seizures because, although they are very common in this disorder, seizures can occur due to other conditions as well. Some types are as follows.

3.1. Epileptic attacks

Epilepsy is one of the main disorders associated with the presence of seizures.

3.2. Feverish attacks and infection

The presence of fevers above 39 degrees can cause convulsive episodes without prior neurological alterations that explain them. They can be simple if they do not repeat and last less than fifteen minutes, or complex if the episode recurs within the first four hours (in this case, they can also be called dispersal or atypical seizures).

3.3. Seizures due to organic deficiencies

The presence of liver or kidney problems can also lead to the onset of seizures.

3.4. Seizures due to substance use

Some drugs and medications can cause seizures, both as a side effect and during overdose, or during withdrawal syndromes.

3.5. hysterical attacks

Seizures don’t just come from medical causes. Certain psychological disorders such as somatomorphs make the subject suffer. These types of seizures have the particularity of generally occurring only in the presence of others which no longer generate alterations in an electroencephalogram (although they are not fictitious symptoms, but generated psychologically).

3.6. Seizures due to anxiety

In certain situations of very high anxiety, it is possible that motor and somatic alterations can occur, being possible that convulsions appear.

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