Types of epilepsies: causes, symptoms and characteristics
Epileptic seizures are complex phenomena, especially taking into account that there are different types of epilepsy .
Already in the Bible, even in Babylonian documents of greater antiquity are references to epilepsy, called at that time morbus sacer or sacred disease, which through which people lost consciousness, fell to the ground and they suffered major convulsions while they were frothing at the mouth and chewing their tongues .
As you can imagine by the name that was originally imposed on him it was associated with religious or magical elements , considering that those who suffered it were possessed or were in communication with spirits or gods.
Over the centuries the conception and knowledge of this problem was amplified, finding that the causes of this problem lie in the functioning of the brain. But the term epilepsy does not refer only to the type of crisis mentioned above, but actually includes different syndromes. Thus, we can find different types of epilepsy.
- To learn 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 several group of hyperexcitable neurons are activated abruptly, continuously, abnormally and unexpectedly, causing an excess of activity in the hyperexcited areas that lead to loss of organism control .
It is a chronic disorder that can be generated by a large number of causes, with some of the most frequent traumatic brain injuries, strokes, hemorrhages, infections or tumors. These problems cause certain structures to react abnormally to brain activity , being able to 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 nevertheless they only occur in some types of epilepsy. And is that the specific symptoms that the epileptic person will present depends on the hyperactivated area where the crisis begins. However, in general, epileptic seizures are 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 take into account 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, there being three groups in this sense: symptomatic, cryptogenic and idiopathic.
A) Symptomatic crises
We call symptomatic to the crises of which the origin is known . This group is the most known and frequent, being able to locate one or several epileptoid brain zones or structures and a damage or element that causes said alteration. However, at a more detailed level, it is not known what this initial alteration produces.
B) Cryptogenic crises
Cryptogenic crises, currently called probably symptomatic, are epileptic seizures of which It is suspected that they have a certain cause, but whose origin can not yet be demonstrated by the evaluation techniques current It is suspected that the damage is at the cellular level.
C) Idiopathic crisis
In the case of both symptomatic and cryptogenic crises, epilepsy is due to the hyperactivation and abnormal discharge of one or several groups of neurons, activation from a more or less known cause. However, it is sometimes possible to find cases in which the origin of epileptic seizures does not seem to be due to recognizable damage.
This type of crisis is called idiopathic, which is believed to be due to genetic factors . Despite not knowing exactly their origin, people with this type of crisis tend to have a good prognosis and response to treatment in general.
Types of epilepsy according to generalization of the crises
Traditionally, the presence of epilepsy has been associated with two basic types known as great evil and small malignancy, but research carried out over time has shown that there is a wide variety of epileptic syndromes. The different syndromes and types of epileptic seizures they are classified mainly according to whether neural discharges and hyperexcitation occur only in a specific area or at a generalized level .
1. Generalized crises
In this type of epileptic seizures, 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 common that in these types of epilepsy (especially in the crises of great evil) a previous aura appears , that is to say, pródromos or previous symptoms like obnubilación tingling and hallucinations at the beginning of the crisis that can prevent who is going to suffer from its occurrence. Some of the most well-known and iconic in this type of epileptic crisis are the following.
1.1. Generalized tonic-clonic crisis or crisis of great evil
The epileptic crisis prototype, in crises of great evil appears a sudden and sudden loss of consciousness that causes the fall to the floor of the patient , and is accompanied by constant and frequent convulsions, bites, urinary and / or fecal incontinence and even screaming.
This type of 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, to then start in the clonic phase in which seizures appear (Beginning at the ends of the body and progressively generalizing) and finally culminate the epileptic crisis with the recovery phase in which consciousness is gradually regained.
1.2. Crisis of absence or small bad
In this type of epileptic seizure the most typical symptom is the loss or alteration of consciousness , as small stops of mental activity or mental absences that accompany the akinesia or lack of movement, without other more visible alterations occur.
Although the person loses consciousness temporarily, does not fall to the ground nor does it usually have physical alterations (although sometimes contractions can occur in the facial muscles).
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 usually occur together with intellectual disability and problems of personality, emotional and behavior. It is one of the most serious neurological disorders in children, which can cause death in some cases either directly or due to complications associated with the disorder.
1.4. Myoclonic epilepsy
Myoclonus is a spasmodic and abrupt 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 jerking upon awakening from sleep. Many people with this disorder end up having major bad seizures. It often appears as a reaction to light stimulation.
1.5. West syndrome
A subtype of childhood generalized epilepsy in the first semester of life , West Syndrome is a serious and infrequent disorder in which children have disorganized brain activity (something visible by electroencephalogram).
Children with this disorder suffer spasm saves that cause mostly inward limb flexion, 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 the ground due to an initial muscular contraction, but without convulsions and rapidly recovering. Although it produces brief episodes, it can be dangerous, since falls can cause serious effects due to trauma.
2. Partial / focal crisis
Partial epileptic seizures, unlike generalized seizures, occur in specific and specific areas of the brain. In these cases the symptoms vary enormously depending on the location of the hyperactivated dona, limiting the damage to that area although in some cases the crisis may become generalized. Depending on the area, the symptoms can be motor or sensitive, causing hallucinations to convulsions in specific areas.
These crises can be of two types, simple (it is a type of epileptic crisis located in a certain area, and that does not affect the level of consciousness) or complex (which do alter the psychic abilities or consciousness).
Some examples of partial crises may be the following
2.1. Jacksonian crisis
This type of crisis is due to a hyper-excitation of the motor cortex, causing localized seizures at specific points that in turn follow the somatotopic organization of the cortex.
2.2. Benign partial epilepsy of childhood
It is a type of partial epileptic seizure that occurs during childhood. They usually occur during sleep, not producing a serious alteration in the development of the subject. They usually disappear on their own throughout their development, although in some cases they may lead to other types of epilepsy that are serious and affect the quality of life in many of their areas.
One last consideration
In addition to the aforementioned types, there are also other convulsive processes similar to those of epileptic seizures, such as occurs in cases of dissociative and / or somatoform disorders, or seizures during fever. However, although in some classifications they are classified as special epileptic syndromes, there is some controversy, some authors not agreeing to be 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.
