Types Of Epilepsies: Causes, Symptoms And Characteristics

Epilepsy can be classified into different categories based on its symptoms and signs.

Epileptic seizures are complex phenomena, especially considering that there are different types of epilepsy.

Already in the Bible, even in older Babylonian documents there are references to epilepsy, called at that time morbus priest or sacred disease, which through which people lost consciousness, fell to the ground and suffered major convulsions while releasing They foam at the mouth and bite their tongues.

As you can imagine from the name that was originally imposed on it, it was associated with elements of a religious or magical nature, considering that those who suffered from it were possessed or were in communication with spirits or gods.

With the passing of the centuries, the conception and knowledge of this problem grew, finding that the causes of this problem lie in the functioning of the brain. But the term epilepsy does not refer only to the aforementioned type of seizures, but actually includes different syndromes. Thus, we can find different types of epilepsy.

A disorder of neurological origin

Epilepsy is a complex disorder whose main characteristic is the presence of repeated nervous crises over time in which one or several groups of hyperexcitable neurons are activated in a sudden, continuous, abnormal and unexpected way, causing an excess of activity in the hyperexcited areas that lead to loss of body control.

It is a chronic disorder that can be generated by a large number of causes, some of the most frequent being head trauma, stroke, hemorrhage, infection or tumors. These problems cause certain structures to react abnormally to brain activity, which can lead to the presence of epileptic seizures in a secondary way.

One of the most common and recognizable symptoms are seizures, violent and uncontrollable contractions of the voluntary muscles, but despite this they only occur in some types of epilepsy. And it is that the specific symptoms that the epileptic person will present depends on the hyperactivated area where the crisis begins. However, seizures are broadly similar, since their action extends to almost the entire brain.

Types of epilepsy according to whether its origin is known

When classifying the different types of epilepsy, we must bear in mind that not all cases are known to produce them. In addition, they can also be grouped according to whether or not their causes are known, with three groups in this sense: symptomatic, cryptogenic and idiopathic.

A) Symptomatic crises

We call the crises of which the origin is known symptomatic . This group is the best known and most frequent, being able to locate one or several epileptoid brain areas or structures and a damage or element that causes said alteration. However, at a more detailed level, it is not known what causes this initial alteration.

B) Cryptogenic crises

Cryptogenic seizures, currently called probably symptomatic, are those epileptic seizures that are suspected of having a specific cause, but whose origin cannot yet be demonstrated by current assessment techniques. The damage is suspected to be at the cellular level.

C) Idiopathic seizures

Both in the case of symptomatic and cryptogenic seizures, epilepsy is caused by hyperactivation and abnormal discharge of one or several groups of neurons, activation coming from a more or less known cause. However, sometimes it is possible to find cases in which the origin of the epileptic seizures does not seem to be due to a recognizable damage. 

This type of crisis is called idiopathic, which is believed to be due to genetic factors. Despite not knowing exactly its origin, people with this type of crisis tend to have a generally good prognosis and response to treatment.

Types of epilepsy according to generalization of the seizures

Traditionally the presence of epilepsy has been associated with two basic types called great evil and small evil, but research carried out over time has shown that there are a wide variety of epileptic syndromes. The different syndromes and types of epileptic seizures are classified mainly according to whether the discharges and neural hyperarousal occur only in a specific area or at a generalized level.

1. Generalized crisis

In this type of seizure, the electrical discharges from the brain are caused bilaterally in a certain area to end up generalizing to all or a large part of the brain. It is frequent that in these types of epilepsy (especially in grand mal seizures) a previous aura appears, that is, prodrome or previous symptoms such as clouding, tingling and hallucinations at the beginning of the seizure that can prevent who is going to suffer idea. Some of the best known and iconic within this type of epileptic seizure are the following.

1.1. Generalized tonic-clonic crisis or grand mal crisis

The prototype of epileptic seizures, in grand mal seizures there is a sudden and sudden loss of consciousness that causes the patient to fall to the ground, and is accompanied by constant and frequent seizures, bites, urinary and / or fecal incontinence and even screaming. 

This type of seizure crisis is the most studied, having found three main phases throughout the crisis: first, the tonic phase in which the loss of consciousness occurs and the fall to the ground, and then the clonic phase begins. in which seizures appear (beginning in the extremities of the body and progressively generalizing) and finally the epileptic crisis culminates with the recovery phase in which consciousness is gradually regained.

1.2. Crisis of absence or little evil

In this type of epileptic seizure the most typical symptom is the loss or alteration of consciousness, such as small stops in mental activity or mental absences accompanied by akinesia or lack of movement, without other more visible alterations. 

Although the person loses consciousness temporarily, they do not fall to the ground nor do they usually have physical alterations (although contractions in the facial muscles can sometimes occur).

1.3. Lennox-Gastaut syndrome

It is a subtype of generalized epilepsy typical of childhood, in which mental absences and frequent seizures appear in the first years of life (between two and six years of age) that generally occur together with intellectual disability and problems with personality, emotional and behavior. It is one of the most serious childhood neurological disorders, being able to cause death in some cases either directly or due to complications associated with the disorder.

1.4. Myoclonic epilepsy

Myoclonus is a jerky and jerky movement that involves the displacement of a part of the body from one position to another. 

In this type of epilepsy, which actually includes several sub-syndromes such as juvenile myoclonic epilepsy, it is common for seizures and fever to appear more and more frequently, with some focal seizures in the form of jerks on awakening from sleep. Many of the people with this disorder end up having grand mal seizures. It is common to appear as a reaction to light stimulation.

1.5. West syndrome

A subtype of childhood generalized epilepsy that begins in the first semester of life, West syndrome is a rare and serious disorder in which children have disorganized brain activity (visible by EEG). 

Children with this disorder suffer from spasms that mostly cause the limbs to flex inward, or to fully extend, or both. Its other main characteristic is the degeneration and psychomotor disintegration of the infant, losing physical, motivational and emotional expression abilities.

1.6. Atonic crisis

They are a subtype of epilepsy in which loss of consciousness appears and in which the individual usually falls to the ground due to an initial muscular contraction, but without seizures and recovering quickly. Although it produces brief episodes, it can be dangerous, since falls can cause serious damage from trauma.

2. Partial / focal seizures

Partial epileptic seizures, unlike generalized ones, occur in specific and specific areas of the brain. In these cases, the symptoms vary enormously according to the location of the hyperactivated donut, limiting the damage to that area, although in some cases the crisis can become general. Depending on the area, the symptoms can be motor or sensitive, causing from hallucinations to seizures in specific areas. 

These seizures can be of two types, simple (it is a type of epileptic seizure located in a certain area, and that does not affect the level of consciousness) or complex (which does alter mental abilities or consciousness).

Some examples of partial seizures may be the following

2.1. Jacksonian crises

This type of actuarial crisis is due to hyperexcitation of the motor cortex, causing localized seizures at specific points that in turn follow the somatotopic organization of said cortex.

2.2. Benign partial epilepsy of childhood

It is a type of partial seizure that occurs during childhood. They generally occur during sleep, not producing a serious alteration in the development of the subject. They usually disappear on their own throughout development, although in some cases it can lead to other types of epilepsy that are serious and affect quality of life in many of its areas.

One last consideration

In addition to the aforementioned types, there are also other convulsive processes similar to those of epileptic seizures, as occurs in cases of dissociative and / or somatoform disorders, or seizures during fever. However, although in some classifications they are listed as special epileptic syndromes, there is some controversy, and some authors do not agree that they are considered as such.

Bibliographic references:

  • Abou-Khalil, BW; Gallagher, MJ & Macdonald, RL (2016). Epilepsies. In: Daroff RB, Jankovic, J .; Mazziotta, JC & Pomeroy, SK (eds.). Bradley’s Neurology in Clinical Practice. 7th ed. Philadelphia, PA: Elsevier :: chap 101.
  • Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for revised clinical and electroencephalographic classification of epileptic seizures. Epilepsy. 1981; 22: 489-501.
  • Engel, J. Jr. (2006). Report of the ILAE classification core group. Epilepsy; 47: 1558-68.

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