Cryptogenic epilepsy with seizures in adults

According to the international classification valid until last year, symptomatic or secondary, caused by defeat of brain structures, idiopathic, primary (independent, presumably hereditary disease) and cryptogenic epilepsy were isolated. The latter option means that modern diagnostics has not established any reasons for periodic epileptic seizures, and hereditary predisposition is also not traced. The very concept of "cryptogenic" is translated from Greek as "unknown origin" (kryptos - secret, secret, genos - born).

Science does not stand still and, probably, the origin of periodic epileptic seizures of unknown etiology will be established. Experts suggest that cryptogenic epilepsy is a secondary symptomatic disease, the genesis of which can not be established at the current level of diagnosis.

[1], [2], [3], [4]

Epidemiology

Epilepsy and epileptic syndromes are very common neurological pathologies, besides, often leading to severe consequences. The manifestation of epileptic seizures can occur in persons of any gender and at any age. It is estimated that about 5% of the world's population have experienced at least one seizure in their lives.

Every year, the diagnosis of epilepsy or epileptic syndrome is put on average by every 30-50 inhabitants out of 100 thousand people living on the Earth. Most often epileptic seizures occur in infants (from 100 to 233 cases per 100 thousand population). The peak of the manifestation falls on the perinatal period, then the incidence rate is almost halved. The lowest rates in individuals from 25 to 55 years - about 20-30 cases per 100 thousand of the population. Then the likelihood of epileptic seizures increases and from the age of 70 the incidence ranges from 150 cases or more per 100,000 people.

The causes of epilepsy are established in about 40% of cases, so the disease of unknown etiology is not uncommon. Infantile spasms (West syndrome), related to cryptogenic epilepsy, are diagnosed in four to six-month-old children, one child with such a diagnosis occurring on average among 3200 infants.

[5], [6], [7], [8]

Causes of the cryptogenic epilepsy

The basis for the diagnosis of epilepsy are periodic seizures caused by an abnormally strong electrical discharge resulting from the synchronization of brain cell activity on all frequency ranges, which is outwardly expressed in the appearance of sensory-motor, neurological and psychiatric symptoms.

For the emergence of an epileptic fit, the presence of so-called epileptic neurons, characterized by instability of the resting potential (the potential difference of the unexcited cell on the inner and outer sides of its membrane) is necessary. As a result, the action potential of an excited epileptic neuron has an amplitude, duration and frequency substantially higher than normal, which leads to the development of an epileptic attack. It is believed that seizures occur in people who have a hereditary predisposition to such shifts, that is, groups of epileptic neurons that are able to synchronize their activity. Epileptic foci are also formed in places of the brain with altered structure due to injuries, infections, intoxications, development of tumors.

So, in patients who are diagnosed with cryptogenic epilepsy, modern methods of neuroimaging do not reveal any disturbances in the structure of the brain substance, and there are no epileptics in the family history. Nevertheless, patients often have quite frequent epileptic seizures of various types, which are difficult to treat (perhaps, just because their cause is not clear).

Accordingly, the known risk factors for the occurrence of epileptic seizures - genetic, disorder of the brain structure, metabolic processes in its tissues, the consequences of head injuries or infectious processes during surveys and surveys are not detected.

According to the new classification of epilepsy in 2017, six etiological categories of the disease are distinguished. Instead of symptomatic, it is now recommended to determine the type of epilepsy for an established reason: structural, infectious, metabolic, immune, or a combination of them. Idiopathic epilepsy presupposed the presence of a hereditary predisposition and is now called genetic. The term "cryptogenic" is replaced with "an unknown etiologic factor", why the meaning of the wording has become more understandable, but has not changed.

The pathogenesis of epilepsy presumably looks like this: the formation of an epileptic focus, that is, a community of neurons with disturbed electrogenesis. → Creation of epileptic systems in the brain (when the excitatory mediators are released excessively, a "glutamate cascade" is launched that affects all new neurons and favors the formation of new foci of epileptogenesis) interneuronal connections → generalization of epilepsy occurs.

The main hypothesis of the mechanism of epilepsy development is the assumption that the pathological process triggers a disturbance of the equilibrium state between the exciting neurotransmitters (glutamate, aspartate) and those responsible for the inhibition processes (γ-aminobutyric acid, taurine, glycine, noradrenaline, dopamine, serotonin). What exactly violates this balance in our case remains unknown. However, as a result, the cell membranes of neurons suffer, the kinetics of ionic streams is disrupted - ion pumps are inactivated and, conversely, ion channels are activated, the intracellular concentration of positively charged ions of potassium, sodium and chlorine is disrupted. Pathological ion exchange through destructured membranes determines changes in the level of cerebral blood flow. The dysfunction of glutamate receptors and the production of autoantibodies to them causes the appearance of epileptic seizures. Periodically repeating unnecessarily intense neuronal discharges, realized in the form of epipriplets, lead to profound disturbances in metabolic processes in brain cells and provoke the development of the next seizure.

The specificity of this process is the aggressiveness of the neurons of the epileptic focus in relation to the unchanged areas of the brain, which allows them to subordinate new sites. The creation of epileptic systems occurs during the formation of pathological interrelations between the epileptic focus and the structural components of the brain, capable of activating the mechanism of epilepsy development. To such structures belong: the thalamus, the limbic system, the reticular formation of the middle part of the brainstem. The interrelationships that arise with the cerebellum, caudate nucleus of the subcortex, anterior orbital cortex, on the contrary, slow the development of epilepsy.

In the course of the development of the disease, a closed pathological system is formed-the epileptic brain. Her education is completed by the disorder of cellular metabolism and interaction of neurotransmitters, cerebral circulation, the growth of cerebral tissue atrophy and vessels, the activation of specific brain autoimmune processes.

[9], [10],

Symptoms of the cryptogenic epilepsy

The main clinical manifestation of this disease is epileptic seizure. Suspicion of epilepsy occurs when the patient has seen at least two reflex (unprovoked) epileptic seizures, the manifestations of which are very diverse. For example, epileptopodobnye attacks caused by high temperature and not occurring in the normal state, epilepsy are not.

In patients with cryptogenic epilepsy, seizures of different types can occur, and quite often.

The first signs of the development of the disease (before the appearance of full-fledged epileptic seizures) may remain unnoticed. In the risk group, people who suffered from febrile convulsions in early childhood, with a conclusion about increased convulsive readiness. In the prodromal period, sleep disorders, increased irritability, emotional lability may be observed.

In addition, not always attacks take place in classical generalized form with falling, convulsions, loss of consciousness.

Sometimes the only early signs are speech disorders, a patient in consciousness, but does not speak and does not answer questions, or periodic short-lived faints. This does not last long - a couple of minutes, so it is left without attention.

More easily, simple focal or partial (local, limited) seizures occur, the manifestations of which depend on the location of the epileptic focus. The patient does not lose consciousness at the time of paroxysm.

During a simple motor attack, tics, twitching of limbs, muscle cramps, rotational movements of the trunk and head can be observed. The patient can make inarticulate sounds or be silent, without answering questions, smacking, licking, making chewing movements.

Simple sensory seizures are characterized by paresthesias - numbness of various parts of the body, unusual taste or olfactory sensations, usually unpleasant; visual disturbances - flashes of light, mesh, flies before the eyes, tunnel vision.

Vegetative paroxysms are manifested by sudden pallor or hyperemia of the skin, increased pulse, abrupt blood pressure, narrowing or dilating pupils, discomfort in the stomach area up to pain and vomiting.

Mental seizures are manifested by derealization / depersonalization, panic attacks. As a rule, they are harbingers of complex focal seizures, which are already associated with a violation of consciousness. The patient realizes that he has a seizure, but can not seek help. Events that occurred with him during an attack, erased from the memory of the patient. Human cognitive functions are disturbed - there is a feeling of unreality of what is happening, new changes within oneself.

Focal seizures with subsequent generalization begin as simple (complex), transforming into generalized tonic-clonic paroxysms. Three minutes pass and pass into a deep sleep.

Generalized seizures occur in a more severe form and are divided into:

• tonic-clonic, occurring in this sequence - the patient loses consciousness, falls, his body flexes and stretches out an arc, convulsive twitching of muscles begins throughout the body; the patient's eyes roll up, his pupils are dilated at this moment; the patient screams, turns blue as a result of stopping breathing for a few seconds, foamy hypersalivation is observed (the foam can acquire a pinkish tinge due to the presence of blood in it, which indicates the bite of the tongue or cheek); Sometimes there is an involuntary emptying of the bladder;
• myoclonic ones look like intermittent (rhythmic and irregular) jerking of the muscles for several seconds all over the body or in separate parts of the body that look like swings of limbs, squats, clenching of hands into fists and other monotonous movements; Consciousness, especially with focal seizures, persists (more often this species is observed in childhood);
• absences - non-convulsive seizures with a short-term (5-20 seconds) disconnection of consciousness, is expressed by the fact that a person freezes with open eyes that do not express anything and does not react to stimuli, usually does not fall, when he regains consciousness, continues his interrupted activity and does not remember the seizure ;
• Atypical absences are accompanied by falls, involuntary emptying of the bladder, more prolonged and occur in severe forms of the disease, combined with mental retardation and other symptoms of mental disorders;
• Atonic seizures (akinetic) - the patient falls sharply as a result of loss of muscle tone (with focal epilepsies - there may be atony of separate muscle groups: facial - sagging of the lower jaw, cervical - the patient sits or stands dangling his head), the duration of the seizure is not more than one minute; Atony at absences begins gradually - the patient slowly settles, with isolated atonic seizures - falls sharply.

In the post-fatal period the patient is sluggish and slowed down, if not to brake, he falls asleep (especially after generalized ones).

Types of epilepsy correspond to types of seizures. Focal (partial) seizures develop at a local epileptic focus, when an abnormally intense discharge meets resistance in neighboring areas and is extinguished, not spreading to other parts of the brain. In such cases, cryptogenic focal epilepsy is diagnosed.

The clinical course of the disease with a limited epileptic focus (focal form) is determined by the location of its localization.

Most often observed lesion of the temporal region. The current of this form is progredient, seizures often have a mixed type, continue for several minutes. Cryptogenic temporal epilepsy outside of attacks is manifested by headaches, constant dizziness, nausea. Patients with this form of localization complain of frequent urination. Before a fit, patients feel the aura-harbinger.

The lesion can be located in the frontal lobe of the brain. Seizures are characterized by suddenness without a prodromal aura. The patient has twitching of his head, his eyes are rolling under his forehead and aside, his automatic gestures are quite complicated. The patient may lose consciousness, falls, he has tonic-clonic muscular spasms all over his body. With this localization, there are a series of short-lived seizures, sometimes with a transition to generalized and / or epistatus. They can begin not only during the daytime wakefulness, but during the night sleep. Cryptogenic frontal epilepsy, developing, causes mental disorders (violent thinking, derealization) and the autonomic nervous system.

Seizures of a sensory type (sensation of warm air movement over the skin, light touch) are combined with convulsive twitching of parts of the body, verbal and motor disorders, atony accompanied by urinary incontinence.

The localization of the epileptic focus in the orbital-frontal area is manifested by olfactory hallucinations, hypersalivation, epigastric discomfort, and verbal disorders, coughing and swelling of the larynx.

If electrical hyperactivity cascades spread to all parts of the brain, a generalized seizure develops. In this case, the patient is diagnosed with cryptogenic generalized epilepsy. In this case, seizures are characterized by intensity, loss of consciousness and result in a patient's prolonged sleep. Upon awakening, patients complain of headache, visual phenomena, weakness and devastation.

There are also combined (when both focal and generalized seizures occur) and an unknown type of epilepsy.

Cryptogenic epilepsy in adults is considered, and not without grounds, secondary with an unidentified etiological factor. Characterized by the suddenness of seizures. Outside the manifestations of clinical symptoms, epileptics have an unstable psyche, an explosive temperament, a tendency to aggression. Usually the disease begins with the manifestation of some focal form. As the disease develops, foci of the lesion spread to other parts of the brain, for a neglected stage, personal degradation and expressed mental abnormalities are characteristic, and social disadaptation of the patient occurs.

The disease has a progressive course and the clinical symptoms of epilepsy vary depending on the stage of development of epilepsy (the prevalence of epileptic focus).

[11], [12], [13], [14],

Complications and consequences

Even in mild cases of focal epilepsy with single rare seizures, nerve fibers are damaged. The disease has a progressive course, when one attack increases the probability of the next, and the area of brain damage expands.

The generalized frequent paroxysms destructively act on the brain tissue, can develop into an epistatus with a high probability of a lethal outcome. There is also the danger of brain edema.

Complications and consequences depend on the degree of damage to the structures of the brain, the severity and frequency of seizures, concomitant diseases, the presence of harmful habits, age, the adequacy of the selected therapeutic tactics and rehabilitation measures, and the responsible treatment of the patient.

At any age, injuries of varying severity can occur during falls. Hypersalivation and a tendency to vomit reflexes during seizures increase the risk of getting liquid substances into the respiratory system and the development of aspiration pneumonia.

In childhood, instability of mental and physical development takes place. Cognitive abilities often suffer.

Psycho-emotional state is not stable - children are irritable, capricious, often aggressive or apathetic, they lack self-control, they do not adapt well in the team.

In adults, these risks are supplemented by traumatism in the performance of works requiring increased attention. During seizures, there is a biting of the tongue or cheek.

In epileptics, the likelihood of developing depression, mental disorders, social disadaptation increases. Persons suffering from epilepsy are limited in physical activity, choice of profession.

[15], [16], [17], [18]

Diagnostics of the cryptogenic epilepsy

In the diagnosis of epilepsy, many different methods are used to help differentiate this disease from other neurological pathologies.

First of all, the doctor must listen to the complaints of the patient or his parents, if it is a child. An anamnesis of the disease is compiled-the details of the manifestation, the specific nature of the course (frequency of seizures, syncope, the nature of seizures and other nuances), the duration of the disease, and the presence of similar diseases in the patient's relatives. This survey suggests a type of epilepsy and localization of the epileptic focus.

Blood and urine tests are assigned to assess the general condition of the body, the presence of factors such as infections, intoxications, biochemical disorders, to determine the presence of genetic mutations in the patient.

Neuropsychological testing is performed, which allows to assess cognitive abilities and emotional status. Periodic monitoring allows you to assess the impact of the disease on the nervous system and psyche, in addition, it also helps to establish the type of epilepsy.

However, first of all, it is instrumental diagnostics, due to which it is possible to estimate the intensity of electrical activity in the brain regions (electroencephalography), the presence in its departments of vascular malformations, neoplasms, metabolic disorders, etc.

Electroencephalography (EEG) is the main method of diagnosis, because it shows deviations from the norm of brain wave intensity even outside the attack - increased convulsive readiness of certain areas or the entire brain. EEG pattern of cryptogenic partial epilepsy - peak-wave or stable slow-wave activity in certain parts of the brain. With the help of this study on the specifics of the electroencephalogram, it is possible to establish the type of epilepsy. For example, with Vest syndrome, irregular, almost non-synchronized arrhythmic slow waves with anomalously high amplitude and spike discharges are observed. In most cases of the Lennox-Gastaut syndrome, an irregular, generalized slow peak-wave activity with a frequency of 1.5-2.5 Hz, often with amplitude asymmetry, is detected on the electroencephalogram during the waking period. During the night rest for this syndrome is characterized by the recording of rapid rhythmic discharges with a frequency of about 10 Hz.

In the case of cryptogenic epilepsy, this is the only way to confirm its presence. Although there are cases when even immediately after a convulsive fit on an electroencephalogram, changes in the form of brain waves are not recorded. This may be a sign that changes in electrical activity occur in the deep structures of the brain. Changes in the electroencephalogram can also occur in patients without epilepsy.

Necessarily modern methods of neuroimaging are used: computer, resonance, positron emission tomography. This instrumental diagnosis makes it possible to assess changes in the structure of the brain substance due to trauma, congenital anomalies, diseases, intoxications, detect neoplasms, etc. Positron emission tomography, also called functional MRI, helps to identify not only structural, but also functional disorders.

Deeper pockets of abnormal electrical activity allow one-photon emission computer tomography to be identified, resonance spectroscopy can detect abnormalities in biochemical processes in the brain substance.

The experimental and non-common method of diagnosis is a magnetic-encephalography that detects magnetic waves emitted by neurons of the brain. It allows you to explore the deepest structures of the brain, inaccessible to electroencephalography.

[19], [20], [21], [22], [23], [24]

Differential diagnosis

Differential diagnosis is carried out after the maximum possible studies. The diagnosis of cryptogenic epilepsy is put by the method of excluding other species and the causes of epileptic seizures, revealed during the diagnosis, as well as the hereditary predisposition.

Not all medical institutions have the same diagnostic potential, so this diagnosis assumes the continuation of diagnostic studies at a higher level.

Treatment of the cryptogenic epilepsy

There is no single method for treating epilepsy, however, clear standards have been developed that are observed to improve the quality of treatment and the lives of patients.

Prevention

Since the causes of this particular type of epilepsy are not established, then preventive measures have a common direction. A healthy way of life is the absence of bad habits, full nutrition, motor activity provides good immunity and prevents the development of infections.

Careful attitude to their health, timely examination and treatment of diseases and injuries also increases the likelihood of avoiding this disease.

[25], [26], [27], [28]

Forecast

Cryptogenic epilepsy manifests at any age and does not have a specific symptom complex, but manifests itself in a variety of ways - different types of seizures and types of syndromes are possible. Until now, there is no single method for complete cure for epilepsy, but antiepileptic treatment helps in 60-80% of cases of all kinds of diseases.

The average duration of the disease is 10 years, after which the seizures may stop. Nevertheless, from 20 to 40% of patients suffer from epilepsy all their life. Approximately a third of all patients with any kind of epilepsy and die from the causes associated with it.

For example, the cryptogenic forms of the Vest syndrome are prognostically unfavorable. In most cases, they become Lennox-Gastaut syndrome, whose mild forms are amenable to drug control, while generalized patients with frequent and severe seizures may remain for life and are accompanied by severe intellectual degradation.

In general, the prognosis is very much dependent on the time of the beginning of treatment, when it starts in the early stages - the forecast is more favorable.

The outcome of epilepsy can be a lifelong disability. If a person develops a persistent disorder of health as a result of the disease, leading to a restriction of life activity, then this is established by medical and social expertise. She also decides on assigning a specific group of disabilities. To address this issue should, first of all, to the attending physician, who will present the patient to the commission.

[29], [30], [31], [32], [33]