Types of epilepsy

According to the World Health Organization (WHO), today epilepsy is one of the most common causes of diseases of the nervous system. A third of the population identified epilepsy is a lifelong disease and in 30% of cases it leads to a fatal outcome during epileptic status. Every fifth person during his life suffers at least one epileptic attack.

Basic concepts

The attack of epilepsy occurs due to increased electrical activity of nerve cells.

Epilepsy is a chronic disease of the nervous system, characterized by repeated epileptic attacks in the form of motor, sensory, vegetative and psychic manifestations.

Epileptic seizure (attack) is a transient condition that arises from the development of electrical activity of nerve cells (neurons) in the brain and is manifested by clinical and paraclinic symptoms, depending on the localization of the focus of the discharge.

At the heart of any epileptic fit is the development of abnormal electrical activity of nerve cells that form a discharge. If the discharge does not go beyond its focus, or spreads to neighboring parts of the brain, meets resistance and is extinguished, then partial seizures develop (local) in these cases. In the event that electrical activity seizes all the departments of the central nervous system, a generalized attack develops.

In 1989 the international classification of epilepsies and epileptic syndromes was adopted, according to which epilepsy is divided by the type of attack and the etiologic factor.

1. Local (focal, localized, partial) epilepsy:

• Idiopathic (Rolandic epilepsy, reading epilepsy, etc.).
• Symptomatic (epilepsy Kozhevnikova, etc.) and cryptogenic.

This type of epilepsy is placed only if the local character of paroxysms (seizures) is revealed while examining and obtaining data of the electroencephalogram (EEG).

1. Generalized epilepsies:

• Idiopathic (benign family convulsions of newborns, child absentee epilepsy, etc.).
• Symptomatic (West syndrome, Lennox-Gastaut syndrome, epilepsy with myoclonic-astatic seizures, with myoclonic absences) and cryptogenic.

Attacks with this form of epilepsy from the outset are generalized, which is also confirmed by clinical examination and EEG data.

1. Nondeterministic epilepsies (neonatal cramps, Landau-Kleffner syndrome, etc.).

Clinical manifestations and changes in the EEG have features of both local and generalized epilepsy.

1. Special syndromes (febrile convulsions, seizures that occur in acute metabolic or toxic disorders).

Epilepsy is considered idiopathic, if an external cause was not established during the examination, so it is still considered hereditary. Symptomatic epilepsy is exhibited when structural changes in the brain and diseases, whose role in the development of epilepsy is proved, are found. Cryptogenic epilepsies are epilepsies, the cause of which has not been identified, and the hereditary factor is absent.

Risk factors for epilepsy

• Hereditary weighed anamnesis (the role of genetic factors in the development of epilepsy was reliably established);
• Organic brain damage (intrauterine fetal infection, intranatal asphyxia, postnatal infections, brain trauma, exposure to toxic substances);
• Functional disorders of the brain (violation of sleep / wakefulness);
• Changes in the electroencephalogram (EEG);
• Febrile convulsions in childhood.

The clinical picture of any epilepsy consists of seizures, which in their manifestations are diverse. There are two main types of seizures: generalized and partial (motor or focal).

In order to repeatedly not describe the clinical picture of the same seizures with different types of epilepsy, consider them in the beginning.

Generalized seizures

At the time of generalized epilepsy, a person loses consciousness, falls down, tonic and clonic convulsions of the muscles of the whole body appear.

1. Generalized tonic-clonic seizures.

They begin with a loss of consciousness, fall and arcuate stretching of the body, then join the cramps of the whole body. A person rolls his eyes, his pupils widen, a cry arises. Due to convulsive spasm, apnea develops for a few seconds (respiratory arrest) for several seconds, so the patient becomes blue (cyanosis). There is increased salivation, which in some cases happens in the form of bloody suds due to the bite of the tongue, involuntary urination. During an attack, when you fall unconscious, you can get a serious injury. After a fit, a person usually falls asleep or becomes sluggish, broken (post-admission period).

This type of paroxysms (seizures) often occurs with hereditary forms of epilepsy or against the background of toxic brain damage by alcohol.

1. Myoclonic seizures.

Myoclonias are jerky muscle twitching for a few seconds, can be rhythmic or irregular. For this type of seizure, muscle twitching is typical, which can affect individual parts of the body (face, arm, trunk) or be generalized (throughout the body). In the clinic, these attacks will look like a shrug of the shoulders, a wave of the hand, squats, squeezing brushes, etc. Consciousness is often preserved. They occur in most cases in childhood.

1. Absenses.

This type of seizure occurs without convulsions, but with a brief momentary deenergia of consciousness. A person becomes like a statue with open, empty eyes, does not come into contact, does not answer questions and does not react to others. The attack lasts an average of 5 seconds. up to 20 seconds, after which a person comes to himself and continues interrupted activities. About the attack does not remember anything. Falls during typical absences are not characteristic of the patient. Short duration absences can go unnoticed by the person himself or the people around him. More often this kind of attacks is observed at idiopathic epilepsies in children from 3 to 15 years. In adults, as a rule, they do not begin.

There are also atypical absences, which are longer in time and may be accompanied by falls in the person and involuntary urination. They occur mainly in childhood with symptomatic epilepsies (severe organic brain damage) and are combined with a disturbance of the psyche and intellectual development.

1. Atonic, or akinetic seizures.

Man sharply loses its tone, resulting in a fall, which often leads to head injuries. There may be a loss of tonus in separate parts of the body (dangling of the head, dangling of the lower jaw). Absence can also be a loss of tonus, but it occurs more slowly (the person settles), and in this case, it is a sharp, precipitous drop. Atonic seizures last for up to 1 minute.

Partial seizures

1. A simple partial fit.

This group includes motor, sensory, autonomic and psychic simple paroxysms. Manifestations depend on the localization of the epileptic focus in the brain. For example, motor attacks are manifested by twitching, muscle cramps, torso and head rotations, the publication of sounds or, conversely, the stopping of speech when the focus is located in the motor zone of the central nervous system. Also there are chewing movements, smacking lips, licking lips.

Sensory seizures (sensory area in the parietal lobe) are characterized by local paresthesia attacks (crawling, tingling sensation), numbness of the body part, sensation unpleasant taste (bitter, salty) or odor, visual disturbances in the form of "sparks before the eyes" or loss of visual fields, flash (temporal and occipital lobes).

Vegetative seizures are manifested in the form of altered coloring of the skin (blanching or redness), rapid heartbeat, increase or decrease in blood pressure, changes in the pupil, the appearance of unpleasant sensations in the epigastric region.

Mental seizures are a feeling of fear, an influx of thoughts, a change in speech, a feeling of what has already been seen or already heard, the appearance of a feeling of unreality of what is happening. Objects and body parts may appear to be altered in shape and size (for example, the leg seems small and the arm is huge). Mental seizures are rarely independent, often precede complex partial seizures.

During simple partial seizures, consciousness is not lost.

1. Complicated partial seizure.

It is a simple partial attack, but a violation of consciousness will join it. A person realizes his attack, but can not come into contact with surrounding people. All events that occur with a person during an attack are amnesed (forgotten) by himself. Human cognitive functions are disturbed - there is a feeling of unreality of what is happening, new changes within oneself.

1. Partial seizures with secondary generalization.

Begin with simple or complex partial seizures, then go on to generalized tonic-clonic seizures. Lasts up to 3 minutes, after which a person often falls asleep.

Idiopathic epilepsy

With idiopathic epilepsy, no abnormal brain changes are detected on the MRI.

This species is, as a rule, hereditary in nature and manifests itself in childhood, adolescence or adolescence. The course of the main variants of idiopathic epilepsy is benign and is rarely accompanied by mental disorders and other neurological disorders. In the diagnosis, changes in the EEG are detected only during the seizure period. On SCT and MRI, the pathology of the brain is not determined. A good response is given by epilepsy to anticonvulsant therapy and a high percentage of spontaneous remissions (recoveries).

Below are the main types of idiopathic epilepsy:

• Children's absence epilepsy.

The disease begins at the age of 4 years to 10 years with simple absences (short-term deenergizing of consciousness, the child does not comes into contact, does not answer questions and does not react to others), which are repeated many times during the day. In a part of children, generalized tonic-clonic seizures (loss of consciousness, convulsions of the whole body) join the absences.

• Juvenile absenas epilepsy.

In half the cases, he makes his debut with generalized tonic-clonic seizures (see Fig. above), and in the remaining half of the disease begins with simple absences. In 10% of patients in the anamnesis there are febrile convulsions (convulsions with an increase in body temperature). As a rule, there is a single attack with an interval of 2-3 days. Can be treated with valproate.

• Yants syndrome (juvenile myoclonic epilepsy).

A common form of epilepsy, which is often confused with frontal epilepsy. In half of the cases begins in adolescence. The clinic is represented by various myoclonias (muscle twitching), more often in the muscles of the arms and shoulder girdle. Twitchings can be of different severity, from barely noticeable to pronounced. After a while from the onset of the disease, generalized seizures may join. The frequency of seizures varies, from daily to one case in several weeks. Provoke an attack can be a violent awakening, a sense of anxiety, insomnia, alcohol intake or sudden strong stimuli. The diagnosis is made on the basis of clinical examination and EEG data. High frequency of relapses distinguishes this form of epilepsy from others.

• Epilepsy with generalized convulsive attacks.

The onset of the disease also falls on adolescence. The frequency of seizures varies in a wide range (from once a week to once a year). The disease is genetically determined. In some cases, absences or myoclonic seizures may join the generalized tonic-clonic seizures. Treatment is started with valproate or carbamazepine. With properly selected therapy, remission occurs in 90% of patients.

• Benign neonatal family cramps.

The disease is of a family nature, inherited by an autosomal dominant type and is extremely rare. The first symptoms appear in the child's newborn period (up to 28 days of life). Moms observe the baby's convulsive twitching of the muscles of the body, in some children there may be a short-term apnea (stopping breathing). The course of the disease is favorable, rarely generalized tonic-clonic seizures develop. The appointment of long-term antiepileptic therapy is not rational, since to the age of one year of the child, in most cases, there comes an independent remission.

• Rolandic epilepsy (benign pediatric epilepsy with centrally located spikes).

The debut of the disease falls on the children's age (2-10 years) in 80% of cases. The clinical picture is represented by simple motor (facial muscle cramps, twitching of the tongue, speech disturbance, the appearance of a hoarse voice, wheezing, etc.), sensory tingling on the face) or vegetative attacks (redness of the face, palpitations), which in most cases appear at night (during the period of falling asleep and awakening). Sometimes there are complex partial seizures (see Fig. above) and very rarely secondary generalized seizures (see Fig. higher). The attack is preceded by an aura: a tingling sensation, an electric current, a "crawling craw". The seizure itself is a contraction of one half of the facial muscles or convulsive jerking of the lips, half of the tongue, pharynx. During an attack, salivation increases, the voice disappears, there are squeezed hoarse sounds. In some cases, convulsions can spread to the arm on the same side of the body and, very rarely, to the foot. The attack lasts no more than 2 minutes. The course of the disease is benign: in some children for a lifetime there can be only one episode of partial seizures and in some children older than For 13 years, seizures can stop on their own without medications with anticonvulsants (anticonvulsants).

• Children's epilepsy with occipital paroxysms.

The epileptic focus is in the occipital lobe, therefore, visual functions are disrupted (loss of visual fields, flashes of light in front of the eyes). The second symptom is headaches, which are migraine-like in nature. This form of epilepsy has two origins: early onset (1-3 years) and later (3-15 years). At the early debut of the disease in the clinic there are severe attacks that begin at the moment of awakening child and accompanied by severe vomiting, headache, then there is a turn of the head to the side. The attack ends with generalized seizures or convulsions in one half of the body (hemiconvulsions). Throughout the seizure, consciousness is absent.

With the late onset of the disease, simple sensory seizures are observed in a person (visual hallucinations in the form of small multicolored figures on the periphery of the visual fields). The seizure lasts an average of 1-3 minutes, then is replaced by a severe headache, nausea and vomiting.

In the treatment of drugs of choice are also valproate. The diagnosis is based on EEG data and clinical examination. The course is favorable and remission occurs in 80% or more children.

Symptomatic epilepsy

Craniocerebral trauma can cause the development of symptomatic epilepsy.

The causes of this form of epilepsy include craniocerebral injuries, tumors, birth trauma, infectious-toxic brain damage, arteriovenous malformations, etc.

Symptoms depend on the topical location of the epileptic focus in the brain. There are the following types of symptomatic epilepsy:

• Kozhevnikovskaya epilepsy.

It is a simple motor fits: convulsions in the hand or face, the intensity of which can vary. A special feature of Kozhevnikovskaya epilepsy is the duration of the attack, which can last for several days and leaves behind a paresis (weakness) of that part of the body where there have been twitchings. In a dream, twitching may decrease or disappear. As a rule, only one side of the body is involved in the process (left arm and left leg, right half of face, etc.). Absences with kozhevnikovskoy epilepsy are not found.

In children, the disease most often occurs after the encephalitis of an unknown etiology. Treatment is primarily aimed at eliminating the cause and purpose of anticonvulsants. For this type of epilepsy, there is also a surgical method of treatment, which is used for ineffectiveness of conservative therapy and severe disease.

• Frontal-lobe epilepsy.

One of the most diverse in clinical manifestations of epilepsy. Characteristic of the sudden onset of an attack, which lasts no more than 30 seconds. and also ends suddenly. The attack represents excessive movements, gestures. Sometimes before the attack a person can feel a sensation of warmth, cobwebs on the body. Characteristic emotional coloring of seizures, may be involuntary urination. Frontal epilepsy often manifests itself as simple and complex (cf. above) partial seizures, as well as myoclonic seizures (twitching of certain muscle groups). Seizures tend to generalize the process and form an epileptic status, occur more often at night.

• Temporal-lobe epilepsy.

The nature of seizures can be different - from simple motor (grasping others, scratching themselves, cramping in the arm or leg) to the secondary generalized. Appears at any age. A person is disturbed by illusions, a sense of unreality of what is happening, since the focus is in the temporal lobe, appear olfactory and taste hallucinations (a salty sensation in the tongue, a sense of smell rot). There is a stiff look, ororalimentatnye automatisms (smacking lips, licking lips, protruding tongue), fear, panic. The timbre of the voice can change, an incoherent speech appears. The attack lasts about 2 minutes. In the treatment of drugs of choice are valproate and carbamazepine. In 30% of cases, epilepsy does not respond to treatment with antiepileptic drugs.

• Dark epilepsy.

A common cause of parietal epilepsy are tumors and craniocerebral trauma (consequences). A person is concerned about sensory seizures that are polymorphic in clinical manifestations (sensations of cold, burning, itching, tingling, numbness etc.), hallucinations (does not feel his body, the sensation of an improper arrangement of parts of the body, for example, the hand "exits" from the abdomen). During an attack, disorientation occurs in space if the epileptic focus is in the non-dominant hemisphere. The seizure lasts no more than 2 minutes, but can be repeated many times, several times a day. Treatment is primarily aimed at eliminating the cause of the disease.

• Occipital epilepsy.

The causes are also different (arteriovenous malformation, tumor, trauma). In the occipital lobe there is a zone of the visual analyzer, therefore in the clinic of the occipital epilepsy there are simple seizures in the form of visual impairment up to blindness, flashbulbs, visual hallucinations, loss of visual fields. Quite often simple partial seizures become generalized convulsions. In some cases, there may be a trembling of the eyelids, turning the head and eyes to the side. In the post-fatal period there is a headache, a general disorder. In the treatment, anticonvulsants are used.

• Infantile spasms.

The disease occurs in children of the first year of life against the backdrop of malformations of the brain, birth trauma, The clinical picture is represented by twitching of the muscles of the trunk, which go in batches. During the attack, the child turns his head, bends his arms and legs, bends "like a penknife" because of contractions of the abdominal muscles. Mental retardation develops.

• The Lenox-Gastaut syndrome.

The causes leading to this disease are diverse (encephalitis, meningitis, brain development abnormalities). The syndrome manifests itself in the age from 1 year to 5 years. Seizures are represented by absences, atonic attacks (sharp bending of the legs in the knee joints, sharp drooping head or rapid loss of objects from the hands) and myoclonic seizures (twitching in the flexors of the hands). Develops a delay in psycho-motor development. In the diagnosis, EEG, MRI and SCT are used together with a clinical examination by a specialist.

The variety of clinical forms of epilepsy, as well as the different manifestations of the same seizure in different people (for example, different intensity of seizures, their frequency, response to therapy) cause considerable difficulties in diagnosing and in the selection of adequate anticonvulsant therapy. Despite this, today in the arsenal of the doctor there are modern diagnostic methods (EEG, MRI, SCT, etc.) that facilitate the process of establishing a definitive diagnosis, as well as medicines of new generations.

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