Epileptic seizures are complex phenomena, especially since there are different types of epilepsy .
In the Bible, even in older Babylonian documents, there are references to epilepsy, which at that time was called morbus sacer or the sacred disease, which caused people to lose consciousness, fall to the ground and suffer major convulsions while foaming at the mouth and biting their tongues .
As can be imagined 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 has expanded, and it has been found that the causes of this problem lie in the functioning of the brain. But the term epilepsy does not only refer to the type of seizures 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 nerve 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 leads to the loss of control of the organism .
It is a chronic disorder that can be generated by a large number of causes, some of the most frequent being head trauma, stroke, bleeding, infections or tumors. These problems cause certain structures to react abnormally to brain activity , which may lead to the presence of secondary epileptic seizures.
One of the most common and recognizable symptoms is seizures, violent and uncontrollable contractions of voluntary muscles, but they still only occur in some types of epilepsy. The specific symptoms that the epileptic person will have depend on the hyperactive zone where the seizure starts. However, in general terms, epileptic seizures are similar, since their action extends to almost the entire brain.
Types of epilepsy according to whether their origin is known
When classifying the different types of epilepsy we have to take into account that not all cases are known to produce them. In addition, they can also be grouped according to whether their causes are known or not. There are three groups in this respect: symptomatic, cryptogenic and idiopathic.
A) Symptomatic crises
We call symptomatic the crises whose origin is known . This group is the best known and most frequent, and it is possible to locate one or several areas or structures of the brain that are epileptic and a damage or element that causes this alteration. However, on a more detailed level, it is not known what produces this initial alteration.
B) Cryptogenic crises
Cryptogenic seizures, now probably referred to as symptomatic, are those epileptic seizures which are suspected of having a certain cause, but whose origin cannot yet be demonstrated by current assessment techniques . It is suspected that the damage is at the cellular level.
C) Idiopathic seizures
In the case of both symptomatic and cryptogenic seizures, epilepsy is caused by the hyperactivation and abnormal discharge of one or more groups of neurons, activated by a more or less known cause. However, it is sometimes possible to find cases in which the origin of the epileptic seizures does not appear to be due to recognizable damage.
This type of crisis is called idiopathic, which is believed to be due to genetic factors . Despite the fact that the exact origin of this type of crisis is not known, people with this type of crisis tend to have a generally good prognosis and response to treatment.
Types of epilepsy according to seizure generalized
Traditionally, the presence of epilepsy has been associated with two basic types called major and minor illnesses, but research over time has shown that there is a wide variety of epileptic syndromes. The different syndromes and types of epileptic seizures are mainly classified according to whether the shocks and neural hyperexcitation occur only in a specific area or at a general level .
1. Widespread crises
In this type of epileptic seizure, the electrical discharges from the brain are provoked bilaterally in a specific 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, previous symptoms such as tingling and hallucinations at the beginning of the seizure which may prevent the person who is going to suffer from it from occurring. Some of the best known and most iconic within this type of epileptic seizure are the following.
1.1. Generalised tonic-clonic crisis or grand mal crisis
The prototype of epileptic seizures in the case of grand mal seizures is a sudden loss of consciousness that causes the patient to fall to the floor , and is accompanied by constant and frequent convulsions, bites, urinary and/or fecal incontinence and even screaming.
This type of epileptic seizure is the most studied, having found three main phases throughout the seizure: firstly the tonic phase in which the loss of consciousness and the fall to the ground occurs, to then begin the clonic phase in which the seizures appear (beginning at the extremes of the body and progressively becoming more widespread) and finally culminating in the recovery phase in which consciousness is gradually regained.
1.2. Absence crisis 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, he or she does not fall to the ground and is not usually physically disturbed (although sometimes contractions of the facial muscles may occur).
1.3. Lennox-Gastaut syndrome
This 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) and usually occur together with intellectual disability and personality, emotional and behavioral problems. This is one of the most serious neurological disorders in children, 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, sudden movement that involves moving a body part 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 on waking from sleep. Many people with this disorder end up having grand mal seizures. It often appears as a reaction to light stimulation.
1.5. West Syndrome
A subtype of generalized childhood epilepsy that begins in the first half of life , West Syndrome is a rare and severe disorder in which children have disorganized brain activity (visible by electroencephalogram).
Children with this disorder suffer from spasms that mostly cause inward bending of the limbs, full extension, or both. Their other main characteristic is the psychomotor degeneration and disintegration of the infant, losing physical, motivational and emotional expression skills.
1.6. Atonic attacks
They are a subtype of epilepsy in which loss of consciousness occurs and in which the individual usually falls to the ground due to an initial muscle contraction, but without any seizures and recovering quickly. Although it produces brief episodes, it can be dangerous, since falls can produce serious effects due to trauma.
2. Partial/focal crises
Partial epileptic seizures, as opposed to generalized ones, occur in specific, targeted areas of the brain. In these cases the symptoms vary greatly depending on the location of the hyperactivated doughnut, limiting the damage to that area although in some cases the seizures may become generalised. Depending on the area, the symptoms may be motor or sensory, causing everything from hallucinations to convulsions in specific areas.
These seizures can be of two types, simple (it is a type of epileptic seizure located in a certain area, and does not affect the level of consciousness) or complex (which does alter the psychic capacities or consciousness).
Examples of partial seizures include the following
2.1. Jacksonian crises
This type of actuarial crisis is due to a hyperexcitation of the motor cortex, causing localized convulsions at specific points that in turn follow the somatotropic organization of the cortex.
2.2. Benign partial childhood epilepsy
This is a type of partial epileptic seizure that occurs during childhood. They generally occur during sleep, not producing a serious alteration in the development of the subject. They usually disappear by themselves during development, although in some cases they can lead to other types of epilepsy that are serious and affect the quality of life in many areas.
One last consideration
In addition to the above-mentioned types, there are also other seizure-like processes, such as dissociative and/or somatoform disorders, or seizures during fever. However, although in some classifications they are included as special epileptic syndromes there is some controversy, some authors do not agree with their consideration as such.
- 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$0027s Neurology in Clinical Practice. 7th ed. Philadelphia, PA: Elsevier::chap 101.
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- Engel, J. Jr. (2006). Informe del grupo básico de clasificación de la ILAE. Epilepsia;47:1558-68.