Types of Epilepsies: Classification and Symptoms

There are many Types of epilepsies And some of them are still quite unknown and misunderstood by society. Epilepsy is a chronic brain disease affecting approximately 50 million people worldwide, being the most common neurological cause of death (WHO, 2016).

This disease can occur at any age and for people of any socioeconomic level, although the majority of people who suffer from it (almost 80%) have a medium-low socioeconomic level (WHO, 2016).

In addition, many people who suffer from this disease and live in developing countries do not receive the treatment they need and are both stigmatized (WHO, 2016).

Only 70% of people with epilepsy respond to treatment. Those who do not respond to treatment usually have to undergo surgery.

Classification of epilepsy syndromes

In addition to helping to better understand the disease, classifications are also made so that there is a universal consensus among all the professionals who study it and that there is no confusion, helping to speed up research and scientific progress.

The classification most commonly known and shared among professionals is the International League against Epilepsy (ILAE), having developed the first classification of epileptic syndromes in 1989 (Gómez-Alonso & Bellas-Lamas, 2011).

This classification categorized epilepsy syndromes based on two fundamental criteria, topographical and ideological, and included three types of epilepsy: partial / focal, generalized and of indeterminate location. You can see an outline of this classification in the table below.

Source: adapted table of (Gómez-Alonso & Bellas-Lamas, 2011)

Although this classification has been widely recognized, it has become obsolete over the years, which is why the ILAE decided to make a new classification that was published in 2010 after several years of meetings and preliminary classifications (Gómez-Alonso & Bellas -Lamas, 2011).

This new classification avoids the division of epilepsy into the focal and generalized categories, since it has been proven over the years that the topography of epilepsy is not so simple. Instead of using topography and ideology criteria, the age of onset of the disease and its etiology have been used.

• According to age We distinguish epilepsies that begin in the neonatal period, in the lactation period, in childhood and adolescence / adulthood, with a less specific relation with age.
• According to the etiology Genetic, structural / metabolic causes and those of unknown cause are differentiated.

Epilepsy is considered to be genetic when given as a direct result of a genetic problem. It is necessary to verify that this genetic problem exists with a molecular genetic study or with well-designed family studies (eg, studies of twins). Many of the electroclinical syndromes are genetic, especially those with early onset.

Epilepsy is considered to be of structural / metabolic cause when there is evidence of a Structural or metabolic disorder .

Included in this category are epilepsies due to trauma or brain injury, as well as epilepsy due to disease, although the disease is genetic (such as Tuberous sclerosis ), Since it is not the genetic cause directly that causes the symptoms of epilepsy.

Epilepsies of unknown cause include some types of epilepsy of which the cause is not known, such as benign rolandic epilepsy, Gastaut benign occipital epilepsy, and Panayiotopoulos syndrome.

The ILAE includes a last criterion for classifying syndromes, the degree of syndromic specificity. According to this criterion, the category with syndromes of greater syndromic specificity would be electroclinical (categorized according to age), followed by constellations and finally those differentiated according to their etiology.

In the table below you can see an outline of the new classification of epilepsy syndromes according to the ILAE.

Source: adapted table of (Gómez-Alonso & Bellas-Lamas, 2011)

Types of epilepsy syndromes

Electroclinical syndrome

- Appearance in the neonatal period

The symptoms usually appear in the first months of the baby's life.

• Benign Family Neonatal Epilepsy (BFNE) . This syndrome is characterized by the baby having seizures for a few weeks and one of his parents, usually one of his parents, also suffered from the syndrome as a baby. A relationship has been found between this type of epilepsy and several genes including chromosomes 8 and 20.

• Early myoclonic encephalopathy (EME) . The baby suffers epileptic seizures with chronic myoclonic seizures (short muscle spasms).

Unfortunately these crises prevent the child from developing normally, making it totally dependent, and more than half of the children who suffer from this condition die before reaching one year of life. The etiology is very diverse, including genetic, structural and metabolic causes.

• Ohtahara syndrome . This is a rare type of epilepsy. The baby suffers epileptic seizures with chronic seizures.

As with EME, these crises prevent the child from developing normally, causing symptoms such as drowsiness (associated with the Encephalopathy ) Y Spasticity (Stiffness), making it totally dependent.

Most children with this condition die before the age of two. Causes can be genetic or structural.

- Appearance during the lactation period

Epileptic syndromes usually appear in the first year of life

• Infantile (infantile) epilepsy with migratory focal seizures . This syndrome is characterized by the appearance of focal refractory epileptic seizures (drug resistant) and is associated with severe encephalopathy.

Crises can originate in any cerebral hemisphere and can migrate from one to another. You may experience episodes of Status epilepticus , With crises that last a long period of time.

Children who suffer from it can not develop properly, they present Cognitive problems And have a very short life expectancy. The cause of this syndrome is not known, but is believed to be related to genetic factors.

• West Syndrome (Infantile spasms) . This syndrome usually appears during the first year of life and is characterized by the presence of epileptic seizures with brief and infrequent spasms.

Although some children respond well to treatment, most suffer from chronic spasms, and may develop a type of epilepsy called Lennox-Gastaut syndrome. Most children suffer from learning disabilities, although the severity of the sequelae will depend on the causes of epilepsy.

• Myoclonic Epilepsy of Infancy (Infant) (MEI) . This syndrome is the same as early myoclonic encephalopathy (EME), with the difference that it occurs when the child is at least one year old.

Most children do not have developmental problems, although some may language development And behavior. Unfortunately, in some cases, children do not respond well to the medication and may suffer more serious sequelae.

• Benign infantile epilepsy (infancy) . This type of epilepsy may be familial or not, depending on whether a family member has also suffered from such a condition. Epileptic seizures usually begin between 4 and 9 months of age.

During crises the child for what he is doing and puts his eyes as if he is looking at the horizon. There can be between 5 and 10 crises a day. Children normally have a normal development, most improve with medication and in others even remits spontaneously.

• Dravet's syndrome . This is a very rare syndrome. Seizures usually begin in the first year of life and are associated with high body temperature (such as febrile seizures).

The crises occur several times a year, are quite long (between 15 and 30 minutes) and are characterized by the presence of seizures (lateralized or not). During the second year of life, crises become more frequent.

Unfortunately this type of epilepsy is very difficult to control medically. Children who suffer from it have serious learning problems and are totally dependent. From the age of 14 or 16, crises are less frequent.

• Myoclonic encephalopathy in non-progressive disorders . This type of epilepsy is characterized by the presence of prolonged status epilepticus with myoclonic seizures. The prognosis of children with this syndrome is not very favorable, most have neurological and behavioral problems. The causes are unknown.

- Appearance during childhood

• Febrile seizures plus (FS +) . This syndrome is characterized by the presence of febrile seizures (with rise in body temperature) that normally begin in the first year of age and last until about 11 years.

• Panayiotopoulos Syndrome . This is a relatively common syndrome (affects 1 in 7 children with epilepsy).

It usually appears between 3 and 5 years of age and is characterized by the presence of autonomic epileptic seizures in which the child presents pallor, discomfort, desire to vomit, dilation of the pupils, increased sweating and often ends With some spasms.

Children with this syndrome have a good prognosis since it usually remits spontaneously.

• Epilepsy with myoclonic-atonic crisis . Formerly known as asthmatic epilepsy or Doose syndrome. This type of epilepsy is characterized by the presence of epileptic seizures with myoclonic seizures followed by loss of muscle tone. Children who suffer from this syndrome have no developmental problems.

• Benign epilepsy with centrotemporal tips (BECTS) . The crises usually appear between the 3 and the 14 years of age and to send between the 13 and 18 years. During crises, the child experiences seizures that can be hemifacial, and suffer neurological problems that are reflected in the language, but they are reminiscent as the crisis passes.

• Autosomal dominant nocturnal epilepsy (ADNFLE) . This syndrome usually begins about 9 years of age. During crises, patients experience seizures or loss of muscle tone while they are sleeping. The prognosis is quite good, although on rare occasions a cognitive decline has been found.

• Occipital epilepsy of late onset childhood (Gastaut type) . This syndrome usually appears between the 8 and 9 years of age and usually sends between 2 and 4 years after its appearance. Epileptic seizures are similar to those of benign epilepsy with centrotemporal tips. The prognosis is quite favorable.

• Lennox-Gastaut Syndrome . This syndrome usually begins between 3 and 5 years of age. The types of seizures are very heterogeneous and may vary from individual to individual including atonic seizures, absence seizures and seizures. The prognosis is rather unfavorable, crisis management is limited even with medication and children who suffer from it have intellectual deficits. In some patients, the crises occur in adolescence.

• Epileptic encephalopathy with continuous tip-wave during sleep (CSWS) . Sometimes called Epilepticus Status during Slow Sleep (ESES). People with this type of epilepsy have a pattern of electroencephalogram (EEG) called a tip-wave while they are asleep. Patients undergo progressive cognitive and behavioral decline.

• Landau-Kleffner's Syndrome (LKS) . This syndrome usually appears before the child turns 6 years old. Usually, seizures first appear with seizures, and children begin to have problems with language comprehension and production, and may develop an agnosia verbal auditory (inability to recognize words).

Seizures often disappear when the child is about 5 years old, although he or she may continue to have language, behavioral and learning problems.

• Epilepsy with Childhood Absence (CAE) . This is one of the most common types of childhood epilepsy. It usually begins when the child is between 4 and 7 years old and is characterized by the presence of epileptic seizures in which the child loses consciousness, stops doing what he is doing and remains absent (hence his name).

These crises can occur several times a day during the year and sometimes are accompanied by automatisms (repetitive movements of fingers, hands, mouth...). Fortunately epilepsy usually disappears in adolescence and the prognosis is quite favorable.

- Appearance during adolescence and adulthood

• Epilepsy with Juvenile Absence (JAE) . This type of epilepsy is similar to epilepsy with childhood absences, but early in adolescence.

• Juvenile myoclonic epilepsy (JME) . This type of epilepsy is one of the most common. People who suffer from it have epileptic seizures, often photosensitive, with Generalized seizures And myoclonic. The prognosis depends on the patient's response to treatment, but they do not usually have cognitive problems.

• Epilepsy with generalized tonic-clonic seizures . Also very common. It usually begins when the person is about 20 years old and is characterized by the presence of epileptic seizures with generalized seizures that occur more frequently if the person has slept poorly, is tired or has taken alcohol.

In general has a good prognosis, development and cognitive abilities of the person are often normal, but to control the seizures is necessary to take the medication.

• Progressive myoclonic epilepsies (PME) . It is characterized by the presence of epileptic seizures with myoclonic and tonic-clonic seizures. This type of crisis is what everyone imagines when we talk about an epileptic seizure: the person becomes stiff and then loses muscle tone, falls to the ground and the seizures begin.

Unfortunately it is a chronic disease and not all patients respond well to medication to control seizures.

• Autosomal dominant epilepsy with auditory characteristics (ADEAF) . This type of epilepsy is hereditary. It is characterized by the presence of epileptic seizures with Focal seizures And auditory symptoms such as small auditory illusions, distortions and inability to understand language.

The prognosis is quite favorable, people usually do not have developmental problems or cognitive deficits and crises can be controlled with medication.

• Other familial temporal lobe epilepsies . The epileptic seizures suffered by patients with this syndrome include a pattern of certain strange sensations, different for each individual that may include the memory of old memories, auditory, visual, olfactory or gustatory hallucinations. The prognosis is good, crises are controlled quite well with medication.

- With less specific relation to age

• Focal familial epilepsy with variable foci . This is a hereditary syndrome that may appear from infancy to adulthood and is characterized by the presence of epileptic seizures with focal seizures.

Developmental and cognitive skills are usually kept normal and crises can be controlled with medication.

• Reflex epilepsies . This type of epilepsy differs from the previous ones in that the epileptic attacks do not appear spontaneously, if not in response to a stimulus or an activity of the patient.

Stimuli can be simple (eg, flashing lights, touching or drinking something hot, staying in the dark...) or complex (eg, brushing teeth, listening to music...) as well as actions (p. Walking, reading, doing mental calculations...).

Distinctive constellations

• Medial temporal epilepsy with sclerosis hippocampus (MTLE with HS) . The epileptic seizures usually begin with a sensation in the abdomen that something is going to happen (abdominal aura) and continue with golden, natural, gestural and verbal automatisms.

This type of epilepsy is usually pharmacoresistant but can usually be cured with a surgical operation.

• Rasmussen's syndrome. This is a rare disease that occurs when one of the two hemispheres becomes inflamed, although the cause of this inflammation is not yet known. Inflammation causes focal seizures on the contralateral side of the body.

This syndrome can disappear over the years, although the continuous inflammations can leave sequels as problems of the development.

• Gellular crisis with hypothalamic hamartoma . Gellular crises are characterized by the presentation of sudden and involuntary laughter or laughter that are often described as"cold"or"without emotion".

They are usually caused by a tumor of the Hypothalamus called Hamartoma . Crises are very difficult to control, but removal of the tumor may help improve cognitive symptoms.

• Epilepsy hemiconvulsion-hemiplegia . This type of epilepsy usually occurs as a result of having suffered febrile seizures in a prolonged manner. Seizures are characterized by the presence of unilateral clonic seizures and patients usually develop a Hemiplegia (Paralysis of one side of the body).

With structural or metabolic causes

• Malformations of cortical development (hemimegalencephaly, heterotopias, etc.)
• Neurocutaneous syndromes (tuberous sclerosis complex, Sturge-Weber, etc.)
• Tumor
• Infection
• Trauma
• Perinatal injuries
• Stroke
• Etc.

Epilepsies of unknown causes

These crises occur in isolation, unlike the previous ones, and usually disappear spontaneously without leaving any kind of sequel.

• Benign neonatal seizures (BNS).
• Febrile seizures (FS).

References

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