Types of epilepsies: causes, symptoms and characteristics

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, through which people lost consciousness, fell to the ground and suffered major seizures while foaming at the mouth and biting their tongue.

As you can imagine from the name that was originally imposed on it It was associated with elements of a religious or magical type, 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.

• To know more: "What is epilepsy and how can this neuropathology be treated?"

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 more group of hyperexcitable neurons are activated in a sudden, continuous, abnormal and unexpected way, causing an excess of activity in the hyperexcitable areas what 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 injuries, strokes, hemorrhages, infections 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 is seizures, violent contractions and uncontrollable of the voluntary muscles, but nevertheless 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, epileptic 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 to this, 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 symptomatic the crises of which the origin is known. 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 of which suspected to have a specific cause, but the origin of which cannot yet be demonstrated by assessment techniques current. The damage is suspected to be at the cellular level.

C) Idiopathic seizures

Both in the case of symptomatic and cryptogenic seizures, epilepsy is given from the hyperactivation and abnormal discharge of one or more groups of neurons, activation from more or less causes known. 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 seizure tend to have a good prognosis and response to treatment in general.

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 syndromes epileptics. The different syndromes and types of seizures They 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 by bilaterally in a certain area to end up generalizing to all or a large part of the brain. It is common for these types of epilepsy (especially in grand mal seizures) to have a previous aura., that is to say some prodrome or previous symptoms such as drowsiness, tingling and hallucinations at the beginning of the crisis that can prevent those who will suffer it from its occurrence. 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 epileptic seizure prototype, in grand mal crises 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 of the crisis: in the first place the tonic phase in which the loss of consciousness occurs and the fall to I usually, to then begin in the clonic phase in which the seizures appear (beginning at the extremities of the body and progressively generalizing) and finally culminating the epileptic crisis 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 occurring.

Although the person temporarily loses consciousness, does not fall to the ground nor does it 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 disabilities and personality, emotional and mental problems conduct. It is one of the most serious childhood neurological disorders, and can 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 people with this disorder end up with grand mal seizures. It often appears as a reaction to light stimulation.

1.5. West syndrome

A subtype of childhood generalized epilepsy with onset 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 spasms that mostly cause inward flexion of the limbs, full extension, 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 ground due to an initial muscle 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 depending on 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 an area determined, and does not affect the level of consciousness) or complex (which does alter the psychic abilities or the conscience).

Some examples of partial seizures may be the following

2.1. Jacksonian crises

This type of actuarial crisis is due to hyperarousal of the motor cortex, causing site-specific seizures that in turn follow the somatotopic organization of said crust.

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. Normally they disappear on their own throughout development, although in some cases it can lead to in other types of epilepsy that are serious and that affect the 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 seizures. epileptic, as occurs in cases of dissociative and / or somatoform disorders, or seizures during pictures fever. However, although in some classifications they are listed as special epileptic syndromes, there is some controversy, with some authors not agreeing that they are considered as such.

Bibliographic references:

• Abou-Khalil, B.W.; Gallagher, M.J. & Macdonald, R.L. (2016). Epilepsies. In: Daroff RB, Jankovic, J.; Mazziotta, J.C. & Pomeroy, S.K. (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.