Epilepsy classification

Epilepsy is a severe chronic disease characterized by recurrent, spontaneous seizures. The disease can be traumatic in nature (occurs as a result of injuries) or diencephalic (appears as a result of damage to the diencephalic structure of the brain).

In modern neurology, there are a large number of qualifications of epilepsy, which are based on the clinical and electroencephalographic manifestations of epileptic seizures. For their fixation, EEG and video monitoring are used.

Types of epilepsy

Epilepsy can be congenital (idiopathic) or acquired (symptomatic).

Congenital epilepsy develops as a result of genetic defects in brain structures. As a result, the brain is constantly in convulsive readiness, since an attack can happen suddenly at any moment. The development of congenital epilepsy can be triggered by the following factors:

• birth trauma;
• hypoxia, fetal asphyxia;
• intrauterine infections during pregnancy.

Acquired epilepsy is a more complex and severe disease that can occur in people of any age and is difficult to treat. The disease occurs as a result of pathological changes in the brain caused by the influence of certain external factors. During an epileptic seizure, the patient does not lose consciousness, but cannot control a certain part of the body that has undergone an attack.

Acquired epilepsy occurs as a result of the impact of adverse factors on the brain, which in turn leads to the formation of an epileptic focus that generates an excessive electrical impulse.

Local epilepsy

When diagnosing epilepsy, it is important for specialists to understand whether the seizure affects one of the hemispheres of the brain or the entire brain, thus determining the type of seizure – partial or generalized.
Simple partial seizures can be:

• tonic – they are characterized by the adoption by the patient of a forced posture and muscle tension. After a seizure, the muscles involved in it temporarily weaken;
• sensory – patients have illusions, hallucinations, any part of the body may become numb or tingle;
• vegetative – during attacks, piloerection appears , sweating, heart palpitations, a feeling of a lump in the throat. With such seizures, patients develop a variety of mental disorders.

In complex seizures, patients have impaired consciousness, they do not respond to external stimuli. The duration of such a seizure is usually from 30 to 90 seconds, after which drowsiness and fatigue appear.

Complex seizures of localized epilepsy must be distinguished from absence seizures . In the first case, the source is a focus of pathological activity, and the other is a primary generalized seizure.

Generalized epileptic seizure

With a generalized epileptic seizure, both hemispheres of the brain are involved, so there are no precursors of its development. Generalized epileptic seizures are divided into the following types:

• typical absences – they are characterized by short bouts of impaired consciousness, in which the patient freezes or stops looking. At the end of the seizure, there is no confusion. Lack of treatment threatens repeated repetition of absences . As a rule, they begin to appear in childhood and continue into adulthood;
• atypical absences – seizures are characterized by a pronounced beginning and end, a long duration, mental retardation and motor disorders;
• clonic seizures – myoclonic twitches occur;
• myoclonic seizures – patients develop short, sudden convulsive twitches. Involvement in the attack of the head, neck, upper and lower extremities is characteristic. Similar attacks can have the isolated character or be combined with other attacks;
• tonic seizures – bilateral short attacks of muscle tension develop in the limbs and trunk;
• atonic seizures – the patient’s muscles suddenly lose their tone for a short time. There is a sudden lowering of the head or a fall of the patient. Despite the fact that consciousness is restored fairly quickly, such seizures threaten to cause injury;
• generalized epileptic seizures – patients completely lose consciousness, they lose tonic tension in the muscles of the trunk, arms and legs. Most often, a seizure is preceded by a piercing scream, the appearance of which is associated with the expulsion of air through the closed vocal cords. The muscles tense up, after which a convulsive seizure begins, which is characterized by strong muscle tension, which can be accompanied by fractures and dislocations. After an attack, a person has a headache, drowsiness appears.

Partial epilepsy

A change in the structure of the cerebral cortex in a particular area is called partial epilepsy. This phenomenon is accompanied by chaotic nerve impulses emitted by neurons. Signals are sent to all cells associated with the affected area. The clinical picture reflects a seizure.

As described earlier, there are several options for the development of this type of ailment. Let’s take a closer look at each of them:

• The temporal lobe occupies the position of the most frequent variety, it accounts for 50-60% of all cases associated with the distortion of neural connections.
• Frontal – the second most common manifestation, in about 25% of cases the disease is associated with this particular pathology.
• The occipital is quite rare, no more than 10% of patients.
• Parietal almost never occurs and has a probability of occurrence of less than 1%.

Determination of the localization of the lesion is carried out by means of an EEG (electroencephalogram). Most often, diagnosis is carried out while the patient is at rest, but the most accurate results can only be obtained during an attack. To create such a situation, with the consent of the patient, special means are used.

In addition to classification on a local basis, there is also a system of differences in the severity of the course. There are the following forms:

• Simple – not accompanied by a distortion of consciousness, manifestations are variable and determined by the area.
• Complex – simple seizures with simultaneous impairment of consciousness.
• Secondary generalized (convulsive) – develops from simple and complex seizures, accompanied by convulsions.

This disease is most common in children and develops due to problems during pregnancy or childbirth. For example, from undermining the development of the fetus inside the womb or from a prolonged lack of oxygen during the birth of a child.

The development of the disease in an adult is not excluded. The disease can occur as a result of an injury or other brain disease and will be symptomatic. The following factors may influence its development:

• malignant and benign growths;
• circulatory dysfunction;
• hematomas;
• cyst;
• aneurysms;
• malformations;
• infectious diseases;
• stroke attacks;
• abscess;
• weak intercellular metabolism;
• congenital pathologies;
• traumatic brain injury.

The above disorders dramatically increase the risk of developing a defect due to the formation of pathological signals with an altered intensity from neurons, so it is necessary to seek treatment in time.

The manifestations of the lesion are simple, complex, convulsive and combined. The most common are complex with automatisms and confusion. Before the attack, there is a sensation of olfactory, visual, gustatory, auditory, mental, somatosensory or vegetative-visceral aura.

According to the form, simple, complex, convulsive and combined seizures are distinguished. The duration is up to 1 minute, repetitions are observed. Most often occur at night. Aura is not felt.

Peculiarities:

• high duration;
• minimal impact on consciousness;
• rapid onset of secondary seizures;
• frequent manifestation of motor dysfunctions;
• there are automatisms before a seizure;
• the victim falls.

The back of the brain is focused on the work of the organs of vision, due to which damage to it will affect human vision. During an attack, flies, flashing and colored lights appear in the eyes, or there is a loss of visual fields, followed by severe pain in the head, similar to a migraine.

Drug resistant epilepsy: causes and symptoms

With pharmacoresistant epilepsy, you can undergo a qualitative examination at the Yusupov hospital. The diagnostic center of the hospital is equipped with modern equipment that allows accurate diagnosis in the most difficult situations. Based on a reliable examination, the neurologists and epileptologists of the Yusupov hospital draw up a therapy plan that will be most effective in treating epilepsy in this patient.

Pharmacoresistant epilepsy is conditionally divided into relative and absolute. Relative drug -resistant epilepsy is usually associated with the following factors:

• misdiagnosis;
• the type of seizures is incorrectly set;
• incorrectly selected drug;
• incorrect dosage of the drug;
• severity of adverse reactions;
• violation of the treatment regimen by the patient.

Treatment of epilepsy begins with one first-line drug, for which the dosage is gradually adjusted. At the beginning of treatment, the drug is administered in small amounts, gradually increasing the dose until the desired effect is obtained. If the drug is chosen incorrectly or too low a dosage is used, then pharmacoresistant epilepsy is observed.

Causes of absolute drug resistance include:

• initially incorrectly selected therapy, which led to resistance;
• allergic reactions to the drugs used;
• features of the epileptic syndrome;
• structural damage to the brain;
• features of the human body.

The established status of absolute pharmacoresistant epilepsy requires alternative treatments.

An indicator of pharmacoresistant epilepsy is the presence of 3-4 seizures when using an adequate dosage of an antiepileptic drug. The patient does not decrease the number of seizures, and their intensity remains the same or increases. Epileptic seizures have a different character. The most common types of seizures in patients with epilepsy are:

• tonic-clonic seizures. The patient is constrained by muscle spasm, after which convulsions occur. During an attack, a person falls to the floor (may be injured during a fall), often an uncontrollable cry breaks out from him, loss of consciousness is possible. After an attack, the patient needs rest, he can fall asleep;
• myoclonic seizures. The attack occurs during sleep or upon awakening;
• tonic attacks. They are a characteristic manifestation of the Lennox- Gastaut syndrome . During an attack, there is a strong muscle tension;
• atonic seizures. During an attack, muscle tone abruptly disappears;
• absences . Non-convulsive seizures. During an attack, a person freezes, the gaze is directed to nowhere, the pupils dilate. A person does not react to what is happening around. Often seizures can occur during a conversation or performing an action.

With pharmacoresistant epilepsy, the use of several antiepileptic drugs in the optimal dosage is allowed. If drug therapy is still ineffective, move on to alternative treatment:

• ketogenic diet;
• neurotransplantation of fetal tissues;
• vagus nerve stimulation;
• surgical treatment.

Acquired epilepsy

Acquired epilepsy refers to neurological diseases with a chronic course, it is characterized by the presence of recurrent seizures due to excessive electrical activity of nerve cells in the brain. This type of paroxysm accounts for 25% of cases.

This type of disorder is always secondary, most often the causes of focal epilepsy are associated with:

• metabolic abnormalities;
• abnormal changes in the vessels;
• volumetric processes in the cerebral cortex;
• congenital defects in development;
• head injuries;
• infectious lesions;
• poisoning;
• hypoxia.

The acquired variety is diagnosed with the help of instrumental and laboratory studies. The fundamental method for determining the focus of paroxysmal activity is computer visualization – MRI or CT.

The main causes of the symptomatic variety of the disease:

• head injuries, concussions, bruises and fractures of the skull, which violate the integrity of internal structures and can spur the onset of a seizure;
• infectious diseases such as meningitis, encephalitis and abscess;
• prolonged fever, when the body temperature significantly exceeds the permissible values;
• tumor-like neoplasms in the head;
• vascular disorders;
• the presence of multiple sclerosis;
• drug intoxication;
• alcoholism;
• drug overdose;
• birth trauma in a child associated with hypoxia, head contusion.

Most acquired pathologies have symptoms that are precursors to an incipient seizure:

• headache;
• high irritability;
• feeling of fear;
• numbness or tingling in certain parts of the body;
• darkening in the eyes;
• noise in ears;
• change in blood pressure;
• muscle twitches;
• detachment from reality;
• hallucinations: auditory, olfactory, visual.

The presence of such signs indicates a problem that should be addressed. For any head injury, you should contact the clinic and undergo a comprehensive examination.

There are two main types of paroxysms:

• generalized;
• partial (focal).

For a symptomatic disorder, focal conditions are more characteristic, during which the focus of abnormal excitation in the brain cells extends to some areas of neighboring tissues.

In generalized forms, both hemispheres of the human brain are affected. Seizures are of two types:

• tonic-clonic – the muscles of the whole body are tensed, after which their rhythmic twitching occurs, with or without loss of consciousness, lasting no more than 5 minutes;
• absence – consciousness is turned off for a few seconds or minutes, there is no reaction to external stimuli, involuntary movements of the eyeballs often appear, twitching of the fingers or face is noted.

Partial seizures depend on the area of distribution of the pathological focus. The temporal type of deviation is more common, in which a person has visual and auditory hallucinations with a loss of consciousness. If the focus affects other parts of the brain, then problems are observed:

• with vision;
• with memory;
• with speech;
• with a perception of reality.

The patient’s behavior can change dramatically, he becomes suspicious, overly suspicious, vindictive. Acquired epilepsy on the background of alcoholism is quite common, it is characterized by loss of consciousness, convulsive syndrome, and automatic movements.

focal epilepsy

Especially dangerous for the patient is multifocal epilepsy, due to the presence of several lesions at once. Features of the pathology:

• if all forms of the disease are taken into account, FE accounts for more than 82% of cases;
• in more than 75% of cases, the first attack can be noticed in childhood;
• especially often pathology develops against the background of brain lesions of any etiology: infectious, traumatic, ischemic, as well as as a result of developmental anomalies, as a result of violations of the prenatal and birth period;
• symptomatic focal epilepsy (ICB code 10 G40) occurs in more than 71% of cases.

The development of FE is preceded by the following pathologies:

• malignant and benign tumors;
• serious violations of metabolic processes in the body, including cerebral circulation;
• injuries of the cranium and internal tissues;
• infections of any kind, for example, encephalic or meningococcal;
• violations of the structure of the intracranial substance of a hereditary nature.

The main causes of the disease include factors acquired as a result of a negative impact of any nature on the brain or caused by hereditary diseases.

Pediatric FE is mainly characterized by prenatal problems or congenital diseases. In both cases, certain areas of the cortex are affected. In particular:

• infection inside the womb;
• oxygen starvation;
• strangulation of the newborn during the passage of the birth canal;
• increased intracranial pressure;
• birth injury.

In some cases, the disease manifests itself against the background of underdevelopment of the cerebral cortex of both or one hemisphere. The likelihood that the pathology may disappear as the child grows and develops is very high.

The functional genesis of epileptic seizures with focal seizures is characterized by several zones:

• sector of epileptogenic disorders, corresponding to the site of changes in the morphological type, visible in tomographic studies;
• primary – the compartment of the cortex in which epileptic discharges are formed;
• irresistible – a source of activity observed on electroencephalography, and deciphered as a period between attacks;
• functional deficit – a sector in which disorders accompanying an epileptic seizure are generated.

So, focal epilepsy and what is it in adults and children, how is it classified? There are many parameters for defining a term in medicine. From a neurological point of view, there are three main forms of FE:

• Symptomatic. It is diagnosed if it is possible to clearly fix the cause of the lesion of a certain sector of the medulla. As a rule, instrumental diagnostics are used for this.
• Cryptogenic. It is characterized by the inability to make an accurate diagnosis depending on the location of the lesion. The likelihood that the disease is a secondary manifestation, and the frontal lobe and other departments are not damaged, is high.
• Ideopathic . There is no matter what the cause, the symptoms are idiopathic in nature.

Absence epilepsy

This disease is one of the most common neurological diseases. In one way or another, the symptoms of the disorder appear in about 10% of people. In children, the disease occurs several times more often than in adults, and the treatment of absence epilepsy is much more difficult.

As a trigger mechanism for non- convulsive neuralgia of absence epilepsy in adults, the following are of great importance:

• skull trauma;
• brain tumors and other serious illnesses;
• abuse of alcohol, drugs, smoking;
• hereditary factor.

The main difficulty associated with non- convulsive absence epilepsy – the risk of confusing the disease with thoughtfulness, because of which the disease is often left without proper attention. The symptoms of absence epilepsy in adults are not always clear, but the main signs include:

• defocused gaze;
• lack of response to external influences;
• stopping the sentence in mid-sentence at the time of the attack;
• confused movements of the limbs;
• blinking;
• aimless wandering .

A characteristic feature is the high frequency, in particularly stressful situations, reaching several tens and hundreds of seizures per day. They are provoked by the following phenomena:

• active mental activity;
• excessive relaxation;
• hyperventilation of the lungs;
• lack of sleep;
• flashes of light;
• flickering TV or computer screen.

Absences are manifested by the following clinical picture of simple episodes:

• lasts a matter of seconds;
• the victim has no reaction, and he is unconscious;
• the person does not notice the attack.

Paroxysm can last 5-30 seconds, during which the patient loses conscious perception of the world around him.

Seizures in the temporal lobe of the brain

The development of an epileptic lesion in the temporal lobe of the brain leads to the progression of a certain form of epilepsy. In medicine, it is known as temporal and is divided into several types.

Depending on the location of the epileptic lesion within the temporal region, the following forms of this disease are distinguished:

1. Amygdala epilepsy. It develops regardless of the age of the person. It is observed mainly in persons of infancy or school age. This temporal epilepsy is characterized by severe psychomotor manifestations, accompanied by a disorder of consciousness. At the same time, the patient’s motor activity is preserved, but automated.
2. Hippocampal . It accounts for about 65% of all cases of symptomatic temporal lobe epilepsy. The first manifestation of the disease occurs at the school age of the patient. Most patients have atypical febrile convulsions before the first attack.
3. Lateral. Of all the forms of temporal lobe epilepsy, this one is the most rare. The age of the patient, as a rule, does not play a significant role in the development of the disease. This form is characterized by focal sensory seizures with pronounced manifestations: visual and sound distortions, dizziness in combination with autonomic symptoms, loss of consciousness.
4. Opercular (insular). A form of frontotemporal epilepsy in which the lesion develops in the opercular zone of the brain. The clinical picture of convulsive seizures is represented by profuse salivation, clonic convulsions in the muscles of the face, neck and larynx, a tingling sensation in the throat and half of the face.

The most relevant is the division of temporal lobe epilepsy into:

1. Symptomatic. The most common and frequently encountered form of symptomatic disease is medial, or mesial , temporal sclerosis. Also in medicine there is such a thing as structural temporal lobe epilepsy, which means the morphological characteristics of the pathological condition.
2. Idiopathic. With this form, there are no structural changes in the brain tissues. It develops under the influence of genetic factors.
3. Cryptogenic. One of the most dangerous forms of temporal lobe epilepsy. The disease tends to progress. She is characterized by complex attacks, accompanied by pain in the heart and abdomen. People with cryptogenic temporal lobe epilepsy may become panicky and have olfactory and visual disturbances. Because of the feeling of fear, patients may take unreasonable actions.

The occurrence of temporal lobe epilepsy can be triggered by a number of different factors. They can be divided into two groups:

1. Perinatal. These include those that affect the fetus at the stage of its intrauterine development. They also include generic influencing factors. The impetus for the development of temporal lobe epilepsy can be an injury received during childbirth , oxygen starvation of the fetus, various intrauterine infections such as measles, rubella, syphilis and others, as well as infant asphyxia at the time of birth.
2. Postnatal. These developmental mechanisms imply the occurrence of epileptic activity due to severe traumatic brain injury and infections affecting the central nervous system. This group of factors also includes hemorrhagic and ischemic stroke. Also, brain lesions such as large tumors, hematoma, cerebral aneurysm, sclerosis and abscess contribute to the progression of the disease.

In more than half of the cases, the disease develops due to medial temporal sclerosis. This ailment can both cause epilepsy and be the result of prolonged convulsive seizures.

Cryptogenic epilepsy

Cryptogenic epilepsy is one of the most complex chronic pathologies of the central nervous system, the development of which is due to unidentified or uncertain causes. The disease is manifested by regularly recurring specific seizures. The cryptogenic form is found in almost 50% of patients suffering from epileptic seizures.

Cryptogenic epilepsy can be partial, temporal, generalized and focal. With cryptogenic focal epilepsy, patients experience frequent paroxysmal conditions (convulsive seizures). The long course of the disease threatens with a change in personality, the so-called “epileptic dementia”.

Depending on the pathological focus, epilepsy can occur in such proportions as:

• frontal;
• temporal;
• occipital;
• parietal.

The frontal form is often accompanied by sudden attacks lasting in short series. In rare situations, secondary generalization occurs due to damage to brain cells.

Pathology is always accompanied by increased activity in the region of the crown, which is responsible for sensitive functions. Affected people experience unusual sensory sensations, such as:

• tingling in only one side of the body;
• distorted perception of one’s own limbs.

Accompanied by partial seizures, refers to the rarest form.

However, scientists concluded that the development of the disease can be triggered by the following factors:

• burdened heredity;
• complications after traumatic brain injury;
• a history of stroke;
• a brain tumor;
• chemical intoxication.

The most likely cause of the pathology is considered to be a genetic predisposition.

The clinical picture of cryptogenic epilepsy is manifested by the following symptoms:

• more severe course of seizures, in contrast to the classical form of the disease;
• reduced effectiveness of drug treatment;
• significantly accelerated rate of personality change;
• different results of diagnostic studies with each subsequent execution.

Each variety of cryptogenic epilepsy has its own characteristic features and symptomatic manifestations that allow differentiating one form from another.

The leading symptom complex of cryptogenic focal epilepsy is recurrent partial paroxysm.

The nature of simple partial seizures is motor, sensitive, vegetative, somatosensory, accompanied by auditory, visual, olfactory or gustatory hallucinations and mental disorders.

Myoclonic epilepsy

Myoclonic epilepsy is a type of epileptic seizures. It has a softer flow. The disease first appears in infants or young children. The debut of myoclonic epilepsy in adulthood is atypical.

Causes of myoclonic epilepsy

Currently, the exact causes of myoclonic epilepsy have not been established. However, doctors identify several predisposing factors. Among them:

• hereditary predisposition. Certain types of myoclonic epilepsy are hereditary. For example, Unferricht-Lundborg disease , Dravet syndrome . If one of the relatives was diagnosed with epilepsy, then subsequent generations are at risk. The probability of occurrence of the disease is 20-30%.
• intrauterine infection. Some infectious agents are able to cross the placental barrier. As a result, the risk of developing not only myoclonic epilepsy, but also mental disorders and developmental defects increases. Myoclonic epilepsy develops at the end of the 2nd or 3rd trimester.
• Diseases during pregnancy are not infectious. This group of diseases includes diabetes mellitus, thyroid pathology, renal, hepatic, heart failure.
• Uncontrolled intake of drugs during pregnancy. Some drugs have pronounced teratogenic properties. Therefore, their reception negatively affects the development of the fetus. Doctors advise avoiding medication during pregnancy. If necessary, all appointments must be performed by a doctor.
• spontaneous mutations. The reasons for these changes have not yet been studied. Allocate provoking factors, the presence of which contributes to mutational processes. Among them, stress, sudden changes in temperature, excessive physical activity.

The clinical picture of myoclonic epilepsy depends on the type of disease. Among the main pathological symptoms are:

• Seizures. The disease is characterized by myoclonic seizures. They are not accompanied by severe pain syndrome. Convulsions most often affect the limbs, less often the face and trunk. The average duration of a seizure is 10-20 minutes. Consciousness is preserved.
• Loss of consciousness. Occurs extremely rarely. Characteristic of the youthful form.
• Tonic-clonic convulsions. This form of seizure is accompanied by loss of consciousness, painful muscle contraction.
• Oligophrenia. Mental retardation occurs in various forms. Most often it is a disorder of creative thinking, intelligence.
• Mental disorders. They are expressed by hallucinations, neuroses and borderline states.