Epilepsy

What is Epilepsy?

Epilepsy is a chronic disease, manifested by repeated convulsive or other seizures, loss of consciousness and accompanied by changes in personality.

The disease has been known for a very long time. His descriptions are found in Egyptian priests (about 5000 BC), doctors of Tibetan medicine, Arabic-speaking medicine, etc. Epilepsy in Russia received the name of epilepsy, or simply epilepsy. The disease is common: 3-5 cases per 1000 population.

Causes of Epilepsy

Despite the long period of study, the etiology and mechanisms of the disease are not well understood.

In newborns and infants, the most common causes of seizures are severe hypoxia, genetic metabolism defects, and perinatal lesions. In children, seizures are in many cases caused by infectious diseases of the nervous system. There is a fairly well-defined syndrome in which seizures develop only as a result of fever – febrile seizures. In 5% of children, convulsions were observed with increasing body temperature at least once in life, and about half of them should have repeated seizures.

At a young age, the main cause of epileptic disorders is a traumatic brain injury, and it should be remembered that it is possible to develop seizures in the acute and later periods. In persons older than 20 years, especially in the absence of a history of epileptic seizures, a possible cause of epilepsy is a brain tumor.

In patients older than 50 years, among the etiological factors of epilepsy should first of all indicate the vascular and degenerative diseases of the brain. Epileptic syndrome develops in 6-10% of patients who have had ischemic stroke, and most often outside the acute period of the disease.

It is important to emphasize that in 2/5 of patients the cause of the disease cannot be established with sufficient evidence. In these cases, epilepsy is regarded as idiopathic. Genetic predisposition plays a role in certain types of epilepsy. Patients with a family history of epilepsy have a higher risk of developing seizures than in the general population. Currently, the genome of the genes responsible for some forms of myoclonic epilepsy is established in the human genome.

Pathogenesis

In the pathogenesis of epilepsy, the leading role is played by a change in the neuronal activity of the brain, which, due to pathological factors, becomes excessive and periodic. Characteristic is the sudden pronounced depolarization of neurons in the brain, which is either local and is implemented in the form of partial seizures, or becomes generalized. Essential disorders of the processes of thalamocortical interaction and an increase in the sensitivity of cortical neurons have been established. The biochemical basis of seizures is the excessive release of excitatory neurotransmitters – aspartate and glutamate – and the lack of inhibitory neurotransmitters, primarily GABA.

Pathomorphology. Dystrophic changes of ganglion cells, karyocytolysis, shadow cells, neuronophagy, glia hyperplasia, abnormalities in the synaptic apparatus, swelling of neurofibrils, formation of “windows” of desolation in the nerve processes, “swelling” of dendrites are detected in the brain of deceased epilepsy patients. These changes are more marked in the motor area of ​​the cerebral cortex, the sensitive area, the hippocampal gyrus, the amygdala, and the nuclei of the reticular formation. Residual changes in the brain associated with infections, injuries, and developmental defects are also identified. These changes are not specific.

Symptoms of Epilepsy

In the clinical picture of epilepsy, a seizure or seizure period and an interictal period are distinguished. It should be emphasized that in the interictal period, neurological symptoms may be absent or be determined by the disease that causes epilepsy (traumatic brain injury, stroke, etc.). The most characteristic symptom of epilepsy is a large epileptic seizure. Usually it starts suddenly, and its beginning is not associated with any external factors. Less commonly, distant seizure harbingers can be established. In these cases, one or two days before him, one feels unwell, headache, sleep disturbance, appetite, and increased irritability. In most patients, seizures begin with the appearance of an aura, which is stereotypical in the same patient. Depending on the irritation of the brain area, from which the epileptic discharge begins, there are several main types of aura: vegetative, motor, mental, speech and sensory. After an aura that lasts for a few seconds, the patient loses consciousness and falls, as if knocked down. The fall is accompanied by a kind of loud cry, caused by spasm of the glottis and convulsive contraction of the muscles of the chest. Convulsions immediately appear, initially tonic: the torso and limbs are stretched out in a state of tension, the head is thrown up and sometimes turns to the side, breathing holds, the veins in the neck swell, the face becomes deathly pale, with gradually increasing cyanosis, jaws are convulsively compressed Tonic the seizure phase lasts 15–20 s. Then there are clonic convulsions in the form of jerky contractions of the muscles of the limbs, neck and trunk. During the clonic seizure period of up to 2–3 min, breathing is often hoarse, noisy due to the accumulation of saliva and retraction of the tongue, cyanosis slowly disappears, foam from the mouth, often stained with blood due to biting of the tongue or cheek. The frequency of clonic convulsions gradually decreases, and at the end of their general muscular relaxation begins. During this period, the patient does not react even to the strongest stimuli, the pupils are dilated, their reaction to light is absent, tendon and protective reflexes are not caused, involuntary urination is often noted. Consciousness remains soporous and only after a few minutes gradually clears up. Often, leaving the soporous state, the patient sinks into a deep sleep. At the end of the seizure, they complain more about weakness, lethargy, drowsiness, but they do not remember anything about the seizure itself.

The nature of seizures may be different. According to the International Classification of Epileptic Seizures, partial (focal, local) and generalized seizures are distinguished. Partial seizures are further subdivided into simple, complex, disturbed and secondarily generalized.

Symptoms in partial seizures are determined by the irritation syndrome in any area of ​​the cortex of the diseased brain. Among the simple partial seizures, the following can be distinguished: with motor signs; with somatosensory or specific sensory symptoms (sounds, flashes of light or lightning); with vegetative symptoms or signs (peculiar sensations in epigastria, pallor, sweating, reddening of the skin, piloerection, mydriasis); with mental symptoms.

For complex seizures, one or another degree of impairment of consciousness is characteristic. In this case, consciousness may not be completely lost, the patient partially understands what is happening around. Often, complex partial seizures are caused by a focus in the temporal or frontal lobe and begin with an aura.

The sensory aura includes a variety of perceptual disorders. The visual aura that occurs when the occipital lobe is affected is usually manifested by seeing bright sparks, shiny balls, ribbons, bright red staining of surrounding objects (simple visual hallucinations) or in the form of images of some individuals, separate body parts, figures (complex visual hallucinations) . The sizes of objects change (macro or micropsia). Sometimes visual fields (hemianopsia) fall out, complete loss of vision (amaurosis) is possible. In the case of the olfactory aura (temporal epilepsy), the patient has a “bad” smell, often in combination with taste hallucinations (taste of blood, bitterness of metal, etc.). The auditory aura is characterized by the appearance of various sounds: noise, cod, rustling, music, and screams. For a psychic aura (with the defeat of the parieto-temporal region) experiences of fear, horror or bliss, joy, a kind of “already seen” experience are typical. The vegetative aura is manifested by changes in the functional state of the internal organs: palpitations, pain behind the sternum, increased intestinal motility, urge to urinate and defecate, epigastric pain, nausea, salivation, sensation of suffocation, chills, blanching or redness of the face, epigastric pain, nausea, salivation, sensation of suffocation, chills, blanching or redness of the face, epigastric pain, nausea, salivation, sensation of suffocation, chills, blanching or redness of the face, epigastric pain, nausea, salivation, sensation of suffocation, chills, blanching, or redness of the face sensorimotor area) is expressed in various kinds of motor automatisms: dropping or turning the head and eyes to the side, automated movements of the limbs, which have a law molecular weight distribution pattern (leg – body – hand – face), thus there sucking and chewing movements. The speech aura is accompanied by the pronouncing of individual words, phrases, meaningless exclamations, etc. With a sensitive aura, patients experience paresthesias (feeling cold, crawling, numbness, etc.) in certain areas of the body. In some cases, with partial seizures, simple or complex, the pathological bioelectric activity, initially focal, spreads throughout the brain – in this case a secondary generalized seizure develops.

In case of primary generalized seizures, both hemispheres of the brain are initially involved in the pathological process. The following types of generalized seizures are distinguished:

• absences and atypical absences;
• myoclonic;
• clonic;
• tonic;
• tonic-clonic;
• atonic.

In children with epilepsy, absense seizures are often observed, which are characterized by a sudden and very short-term cessation of activity (play, conversation), fading, lack of response to the eye. The child does not fall and after a few seconds (no more than 10) continues the interrupted activity. On the EEG of patients during absansa, as a rule, a characteristic peak-wave activity with a frequency of 3 Hz is recorded. The patient is not aware of and does not remember about the seizure. The frequency of absences sometimes reaches several dozen per day.

The international classification of epilepsy and epileptic syndromes should be distinguished from the classification of epileptic seizures, since in some cases of the same patient, especially with severe epilepsy, there are various seizures.

The classification of epilepsy is based on two principles. The first is whether epilepsy is focal or generalized; the second is whether there is any pathology in the patient’s brain (according to MRI, CT studies, etc.); respectively, symptomatic or idiopathic epilepsy is isolated.

Sometimes seizures occur so often that a life-threatening condition develops – status epilepticus.

Status epilepticus is a condition in which the patient does not regain consciousness between seizures or the seizure lasts more than 30 minutes. The most frequent and severe is the tonic-clonic epileptic status.

Diagnosis of Epilepsy

In the presence of seizures with loss of consciousness, regardless of whether they were accompanied by convulsions or not, all patients should undergo an electroencephalographic examination.

One of the main methods of diagnosing epilepsy is electroencephalography. The most typical variants of epileptic activity are the following: sharp waves, spikes (spikes), peak-slow wave, sharp wave-slow wave complexes. Often, the focus of epileptic activity corresponds to the clinical features of partial seizures; The use of modern methods of computerized EEG analysis allows, as a rule, to clarify the localization of the source of pathological bioelectric activity.

There is no clear relationship between the EEG pattern and the type of seizure; At the same time, generalized high-amplitude peak-wave complexes with a frequency of 3 Hz are often registered during absences. Epileptic activity is usually noted on encephalograms recorded during a seizure. Quite often it is also determined on the so-called interictal EEG, especially when performing functional tests (hyperventilation, photostimulation). It should be emphasized that the lack of epileptic activity on the EEG does not preclude the diagnosis of epilepsy. In recent years, the so-called hours-long EEG monitoring, parallel video and EEG monitoring have been applied.

Examination of patients with epilepsy requires computed tomography, preferably an MRI scan; appropriate study of the fundus, biochemical examination of blood, electrocardiography, especially in the elderly.

In recent years, the method of recording evoked visual potentials for the reversion of a chess pattern has been used as an additional method for studying the state of the pathways of visual afferentation in patients with epilepsy. Were identified specific changes in the shape of the visual potential and sensory afterdischarge in the form of converting them into a phenomenon similar in shape to the spike-wave complex.

Epilepsy Treatment

The goal of treatment is to stop epileptic seizures with minimal side effects and guide the patient in such a way that his life is as full and productive as possible. Before prescribing antiepileptic drugs, the doctor should conduct a detailed examination of the patient – clinical and electroencephalographic, supplemented with an analysis of the ECG, kidney and liver function, blood, urine, CT or MRI data. The patient and his family should receive instructions about taking the drug and be informed about the actual achievable results of treatment, as well as possible side effects.

Modern tactics of treatment of patients with epilepsy include the following:

• identifying the causes of seizures that are treatable (tumor, aneurysm, etc.);
• elimination of seizure factors (lack of sleep, physical and
  mental stress, hyperthermia);
• correct diagnosis of the type of epileptic seizures and epilepsy;
• the appointment of adequate drug therapy (inpatient or outpatient);
• attention to education, employment, rest of patients, social problems of a patient with epilepsy.

Principles of treatment of epilepsy:

• the conformity of the drug to the type of seizures and epilepsy (each drug has a certain selectivity for one type of seizure and epilepsy);
• if possible, use monotherapy (use of a single antiepileptic drug).

Conservative treatment. Treatment should begin with the appointment of a small dose of antiepileptic drug, recommended for this type of seizure and the form of epilepsy.

The dose is increased in the absence of side effects and maintaining seizures in general. In partial seizures, carbamazepine (Tegretol, Finlepsin, Carbasan, Thymonil), Valproatum (Depakine, Convulex), Phenytoin (Difenin), and Phenobarbital (Luminale) are effective. Preparations of the first stage are carbamazepine and valproate. The average therapeutic dose of carbamazepine is 600-1200 mg per day, valproate – 1000-2500 mg per day. The daily dose is divided into 2-3 doses. The so-called retard drugs, or agents of prolonged action, are very convenient for patients. They are appointed 1-2 times a day (depakin-chrono, finlepsin-firecrackers, tegretol-CR). The side effects of phenobarbital and phenytoin determine their use only as second-line drugs.

In case of generalized seizures, the patterns of prescribing are as follows. Valproates and carbamazepine are effective in generalized tonic-clonic seizures. For absences, ethosuximide and valproate are prescribed. Valproates are considered as drugs of choice for patients with idiopathic generalized epilepsy, especially with myoclonic seizures and absences. Carbamazepine and phenytoin are not indicated for absans, myoclonic seizures.

In recent years, many new antiepileptic drugs (lamotrigine, tiagabin, etc.) have appeared that are distinguished by higher efficacy and better tolerability.

Treatment of epilepsy is a long process. The question of the gradual cessation of antiepileptic drugs can be raised no earlier than 2-5 years after the last seizure (depending on the age of the patient, the form of epilepsy, etc.).

With epileptic status, sibazone (diazepam, seduxen) is used: 2 ml of a solution containing 10 mg of the drug (administered intravenously slowly in 20 ml of 40% glucose solution). Repeated administration is acceptable not earlier than in 10-15 minutes. If there is no effect on sibazon, phenytoin, hexenal or thiopental sodium is administered. 1 g of the drug is dissolved with isotonic sodium chloride solution and in the form of a 1-5% solution is injected very slowly intravenously. At the same time there is a danger of respiratory depression and hemodynamics, therefore, it is necessary to inject drugs with minute pauses after pouring every 5-10 ml of solution. In cases of continued seizures and at their high frequency, inhalation anesthesia should be used with nitrous oxide mixed with oxygen (2: 1). Anesthesia is contraindicated in a deep coma, marked respiratory disorders, collapse.

Surgery. In case of focal epilepsy, the indications for surgery are determined first of all by the nature of the disease that caused the epileptic seizures (tumor, abscess, aneurysm, etc.).

More often in these cases, the need for surgery is not determined by the presence of the patient’s epileptic syndrome, but by the danger to his health and the life of the disease itself, which has led to the occurrence of seizures. This applies primarily to brain tumors, abscesses, and some other bulk formations of the brain.

It is more difficult to determine the indications in cases where the epileptic syndrome is caused by the consequences of the trauma suffered, the inflammatory process, or there is no obvious cause of epilepsy, is detected with difficulty using special methods. In these cases, the main method of treatment is medication. Only a relatively small number of patients with seizures that are not amenable to medical correction, and with the progressive degradation of the personality, there is a need for surgery on the brain.

Due to the complexity and responsibility, the decision on the feasibility of surgery, the examination of patients and the operation itself must be carried out in specialized centers.

The study of brain metabolism using positron-emission or single-photon tomography has a certain value in clarifying the nature of epilepsy (so far such studies are possible only in certain specialized centers).

A special place in the examination of patients suffering from epilepsy are monitored for their condition, behavior and directed research on the bioelectrical activity of the brain.

If surgical treatment is intended, it is often necessary to use electrodes implanted in the deep structures of the brain for long-term recording of the electrical activity of these structures. For the same purpose, multiple cortical electrodes can be used, for installation of which craniotomy is necessary.

If using these methods can detect the center of pathological electrical activity (epileptic focus), there may be indications for its removal.

In certain cases, such operations are done under local anesthesia in order to be able to monitor the patient’s condition and not cause damage to functionally significant brain areas (motor, speech zones).

In focal epilepsy, which has arisen after a craniocerebral injury, cerebral-cerebral adhesions are separated, cysts and glial scars are removed from the brain tissue, respectively, in the area of ​​the epileptogenic focus, the subpial removal of the cortex is made.

One of the particular forms of focal epilepsy to be surgically treated is temporal epilepsy, often caused by birth trauma with the formation of foci of gliosis in the hippocampal and medial regions of the temporal lobe.

The basis of temporal epilepsy is psychomotor seizures, the appearance of which is often preceded by a characteristic aura: patients may experience a feeling of unfounded fear, discomfort in the epigastric region, feel unusual, often unpleasant smells, the experience of “already seen.” Seizures may have the character of motor restlessness, uncontrolled movements, licking, forced swallowing. The patient becomes aggressive. With time comes the degradation of the individual.

For temporal epilepsy, resection of the temporal lobe was used for a long time with some success. Recently, a more benign operation has been used – selective removal of the hippocampus and the amygdala. Termination or reduction of seizures can be achieved in 70–90% of cases.

In children with congenital underdevelopment of one of the hemispheres, hemiplegia and epilepsy that is not amenable to medical correction, in some cases, there are indications for the removal of the entire affected hemisphere (hemispherectomy).

In primary generalized epilepsy, when it is not possible to identify an epileptic focus, the intersection of the corpus callosum (callesotomy) is indicated. During this operation, inter-hemisphere connections are broken and there is no generalization of the epileptic seizure. In some cases, stereotactic destruction of the deep structures of the brain (almond-shaped complex, cingulate gyrus), which are the links of the “epileptic system”, is used.

Epilepsy Prevention

It is recommended to avoid alcohol intake, smoking, strong coffee and tea, overeating, hypothermia and overheating, stay at high altitude, as well as other adverse effects of the external environment. Showing a milk-vegetable diet, long stay in the air, light exercise, adherence to work and rest.

Working capacity. Often depends on the frequency and time of seizures. With rare seizures occurring at night, the ability to work remains, but travel and work at night are prohibited. Fits with loss of consciousness in the daytime limit the ability to work. It is forbidden to work at height, near a fire, in hot workshops, on water, near moving mechanisms, on all types of transport, in contact with industrial poisons, with a fast rhythm, psychological stress and frequent switching of attention.