Absenses in adults and children: typical, atypical, simple and complex

It happens that a person unconsciously at a certain moment loses consciousness - as a rule, it is more common in childhood, and is called "absence". Outwardly it looks like a temporary frozen state with an "empty" look. Absence is considered an easy variant of an epileptic attack: this condition can not be left without attention, since it is fraught with rather negative consequences.

[1], [2]

Epidemiology

For the first time about the absense they began talking in the 17th and 18th century. The term literally translated from French means "absence" refers to a temporary lack of consciousness in a patient. Neurologists also use an additional term referring to the absences - "petit mal", which translates as "a small disease".

Absence belongs to a number of varieties of generalized epilepsy, and is most often found in children of children - mostly from 4 to 7 years, sometimes from two to eight years. In many children, loss of consciousness occurs in combination with other variants of epileptic manifestations.

More girls are ill, but the boys do not exclude the appearance of the disease.

According to statistics, the absence occurs in 20% of all diagnosed childhood epilepsies.

If absence is the dominant clinical symptom, the patient is diagnosed with "absent epilepsy".

Adults suffer much less often - in only 5% of cases.

[3], [4], [5], [6], [7], [8], [9]

Causes of the absenses

The basic reason for the appearance of absences is a violation of the balance of inhibitory and stimulating processes in the nerve cells of the cerebral cortex. Depending on this, there are two types of absences:

• Secondary absence - is caused by factors that change the bio-electrical activity. These factors can be inflammatory processes (abscess, encephalitis), tumor processes. In such a situation, absences becomes a symptom of the underlying pathology.
• Idiopathic absences is a disease with an uncertain etiology. Presumably, this pathology refers to hereditary, as indicated by family episodes of the disease. Idiopathic absences usually occurs between 4 and 10 years.

Despite the fact that absences are considered to be genetically determined pathologies, the nuances of inheritance and the involvement of genes at the moment remain unknown.

[10], [11], [12], [13]

Risk factors

Attacks of spontaneous absence can occur in the presence of one of the risk factors:

• heredity, by the type of chromosome aberration;
• problems that arose during the bearing of the fetus and labor (oxygen starvation, long intoxications, infections, trauma during childbirth);
• neurointoxication and infection;
• head trauma;
• severe exhaustion of the body;
• strong hormonal permutations;
• metabolic disorders, degenerative processes affecting the brain tissue;
• tumor processes in the brain.

In most cases, the recurrence of an attack is also associated with the impact of a certain factor. Such a factor can be a light flash, frequent flashing of episodes, excessive nervous tension, a sharp forced flow of air, etc.

[14], [15], [16], [17], [18], [19], [20],

Pathogenesis

By what mechanism the absance develops, it has not yet been precisely elucidated. Scientists have conducted quite a number of different studies on this issue and found that a certain role in the appearance of the disease is played by the cortex and thalamus, as well as inhibitory and exciting transmitters.

It is possible that the pathogenetic basis is genetically determined abnormal ability of nerve cells. Experts believe that the absence develops with the dominance of blocking activity. This is the main difference between absence and convulsive paroxysm, which is the result of overexcitation.

Hyperinhibiting the activation of the cortex is able to arise, as a compensatory mechanism, for suppressing the accomplished painful excitation.

The development of absence in the child and the overwhelming disappearance of the problem as they grow older indicates the relationship of pathology with the degree of maturation of the brain.

[21], [22], [23], [24], [25], [26], [27], [28], [29]

Symptoms of the absenses

Absence usually develops without any precursors, against the background of an absolute safe state. The attack is spontaneous in nature, it can not be predicted and calculated in advance.

Only in isolated cases, patients note the first signs of an approaching paroxysm. This is a sudden approach of headache and nausea, increased sweating and frequent heartbeats. In some cases, close people notice that immediately before the attack the baby can behave inexplicably - for example, there is unmotivated irritability or capriciousness. In isolated cases, there are auditory, auditory or taste hallucinations.

But, as we have already noticed, the first signs are not observed in all patients. Usually the symptom is common for all cases:

• The attack develops abruptly, and ends in the same way. The patient as if "freezes" externally it can resemble "reverie", without any reaction to the call or other annoying factors. The duration of paroxysm on average is 12-14 seconds, after which the patient comes to, as if nothing had happened. No weakness, no drowsiness after the attack does not arise.
• If the patient suffers from a complex abscess flow, then a "trip" may be accompanied by a tonic component. It can look like this: the patient stops abruptly, if something was in his hands - falls out, the head capsizes backwards. A person rolls his eyes, sometimes makes repeated sounds or smacks (so-called automatisms).

Seizures of absence are repeated with different frequency - from 6-9 per day, up to several hundred times - mostly in a state of vivacity (during the day).

Absence at night is considered a rarity, but its appearance is possible during the phase of slow sleep. It is almost impossible to notice paroxysm from the outside. However, if you attach special sensors to the patient that read the nerve impulses, then you can find the corresponding pathological signs.

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

Absenses in adults

In the adult population, absences develop much less frequently, unlike children - in only 5% of cases. Physicians associate the occurrence of this problem with the lack of necessary therapy at an earlier age - for example, when the patient was a teenager.

The duration of paroxysm in adult patients is a few seconds, so you can not notice an attack from the side. In medicine, this is called the term "small absences" when the attack lasts only a couple of seconds and is repeated infrequently. However, the difficulty lies in the fact that disconnection of consciousness can happen while driving a car, or when working with dangerous devices and mechanisms. A person can "disconnect" when swimming in the pool, or in another potentially dangerous situation.

In adults, the disease can be accompanied by tremors of the upper body and head, which often leads to disruption of motor coordination. However, most often the seizure is not distinguished by any specific symptoms: seizures and eyelid myoclonia are not observed, the patient simply "turns off" for a certain time, suspends its activity, "freezes".

If you ask the patient what happened during these few seconds of a fit, then the person will not be able to answer anything, since his consciousness was turned off for this period.

[34], [35]

Absenses in children

In childhood, absent epilepsy is more often associated with the types of idiopathic epilepsy. This form is mainly hereditary in nature (about 2/3 of patients).

Children's absences occur mostly in girls of two to eight years. The prognosis of such a disease is often favorable, benign: the disease lasts about six years and ends with either complete cure or a sustained sustained remission (up to twenty years). The main condition for a positive outcome is timely detection and treatment.

It should be noted that parents do not always pay attention to the presence of seizures - often they simply go unnoticed. Especially imperceptibly there are absences in infants - such attacks last no more than a couple of seconds, and are not accompanied by any special symptoms.

Depending on the age category, when the absence is first detected, the disease is divided into children's (under seven years) and juvenile (adolescence).

The International Commission of ILAE has identified four children's syndromes, at various stages of which there are absences:

• children's absence epilepsy;
• juvenile absence epilepsy;
• juvenile myoclonic epilepsy;
• myoclonic absense epilepsy.

Most recently, it has been proposed to demolish other syndromes with a typical absences in the classification list:

• myoclonia of the eyelids with absences;
• peroral absence of epilepsy;
• stimulancy-sensitive absence epilepsy.

Atypical paroxysms may be observed in patients with Lennox-Gastaut syndrome, with the syndrome of continued spike-wave activity during slow sleep.

[36]

Forms

Absenses have a number of varieties, depending on the course, stage, form of the underlying disease, on the available symptoms, etc. First of all, the disease is divided into two basic types:

• typical absences (they are also called simple);
• Atypical absences (so-called complex).

Simple absences are short, sharply occurring and ending seizures, proceeding without a pronounced change in the tone of the musculature.

Complex absences often appear in childhood, against the background of disturbed development of the psyche, and are accompanied by symptomatic epilepsy. During paroxysm there is quite a strong hyper or hypotonic musculature, which is also indicated in the classification of the disease. Some specialists use the term "generalized absences" when describing complex paroxysms, which indicates that the disease is accompanied by generalized myoclonias.

According to the degree of change in muscle tone,

• atonic absences;
• akinetic absences;
• myoclonic absence.

These conditions refer to complex absences: they are easily identified by the motor characteristics associated with changes in muscle tone. Atonic paroxysm manifests itself in a reduced muscular tone: this is noticeable by the sagging of hands, head. If the patient was sitting on a chair, then he can literally "slip" off of him. With akinetic paroxysm, the standing patient falls sharply. There may be flexion or extensor movement in the limbs, throwing up the head, bending the trunk. With myoclonic absences, there are typical muscular contractions with a small motor amplitude - the so-called twitchings. Often there are muscular contractions of the chin, eyelids, and lips. Twitchings occur symmetrically, or asymmetrically.

Complications and consequences

In the majority of patients, the typical manifestations of absence disappear about 18-20 years. And only in some cases the disease degenerates into a major epileptic fit - in such patients the problem lasts a long time, or remains for life.

The transition to the status status occurs in 30% of cases. The status lasts about 2 to 8 hours, less often - for several days. Signs of such complications are confusion of consciousness, varying degrees of disorientation, inadequate behavior (with stored movements and coordination). Speech activity is also disturbed: the patient speaks mostly simple words and phrases, like "yes", "no", "I do not know".

Specialists pay attention to several signs indicating a positive trend of absence:

• early onset of the disease (between four and eight years) with a normal level of intelligence development;
• absence of other paroxysmal conditions;
• positive shifts during monotherapy with the use of one anticonvulsant medication;
• unchanged EEG picture (not to account - typical generalized "peak-wave" complexes).

Atypical absences do not respond well to treatment, so the consequences for such diseases depend on the course of the underlying pathology.

During the onset of attacks, there may be difficulties with socialization: the occurrence of seizures and the degree of their manifestation is difficult to foresee. Do not exclude the possibility of injury during paroxysm. Thus, patients often experience falls, head injuries, and fractures.

[37], [38], [39], [40], [41],

Diagnostics of the absenses

The main diagnostic procedure, which allows for confirmation of absence, is the evaluation of brain electrical activity, or electroencephalography. EEG is a very sensitive research technique, indicating minimal functional changes in the cerebral cortex and deep structures. EEG has no alternative: even known diagnostic procedures of PET (two-photon emission tomography) and fMRI ( functional magnetic resonance tomography ) can not be compared with this method for informativeness.

Other methods are only used if, for some reason, the EEG is not possible:

• Magnetic resonance imaging;
• CT scan;
• positron emission tomography;
• single photon emission tomography.

The listed diagnostic procedures help to register structural changes in the brain - for example, traumatic injuries, hematomas, tumor processes. However, these studies do not provide information on the activity of brain structures.

Electroencephalography is capable of demonstrating a distinctive moment at a typical absense - the disturbed consciousness correlates with generalized spike and polyspike-wave activity (the frequency of discharges is 3-4, rarely 2.5-3 Hz).

At an abnormal absence, the EEG exhibits slow wave excitations - less than 2.5 Hz. Discharges are distinguished by inhomogeneity, irregularities and asymmetry of peaks.

[42], [43]

Differential diagnosis

Distinguish the absence from other varieties of epilepsy, where short-term impairment of consciousness is only one of the leading symptoms. For example, typical differences are typical absences from complex focal seizures.

	Seizures of focal epilepsy	Typical absence
Prior aura	Everywhere.	Absent.
Duration	Basically, more than a minute.	5-20 seconds.
Influence of hyperventilation	In isolated cases.	Everywhere.
Photosensitivity	In isolated cases.	In many cases.
Loss of consciousness	As a rule, it is deep.	Variations are possible, depending on the flow.
The emergence of automatism	Almost always, with the involvement of one side of the trunk and the limb.	Malovyrazhennye, without involving the trunk and extremities.
The emergence of ambulatory automatisms	Everywhere.	Only with the status of absence.
The appearance of clonic seizures	In rare cases, unilateral, as the end of an attack.	Often, on a bilateral type, near the mouth and eyelids.
Absence of seizures	In isolated cases.	Quite possible.
Postpristupnaya symptomatology	Almost in all cases: confused consciousness, amnesia, dysphasia.	Absent.

Paroxysms of focal epilepsy are characterized by combined motor automatisms, hallucinogenic states, and a rich post-clinic.

Absence or thoughtfulness?

Many parents at first can not tell whether the child has an absence, or the baby just thinks for a few seconds? How to determine if this is an attack?

In a similar situation, doctors advise loudly to knock or clap their hands. If the child turns on the sound - it means that it is a false absense, or a banal "reverie". Exact answer to this question is possible only after the diagnostic EEG.

Treatment of the absenses

Treatment for the emergence of absences is quite difficult - primarily because periodically there is resistance of the body. Therefore, the approach to therapy should be individual and differentiated: anticonvulsant drugs are prescribed in accordance with the type and etiology of seizures.

• With typical absences, monotherapy is acceptable, using ethosuximide, valproic acid. The offered medicines demonstrate the effect in more than 70% of patients. With the development of resistance monotherapy is combined with lamotrigine, in small doses.
• In idiopathic variants of absentis flow, monotherapy with anticonvulsant drugs is performed, showing activity against all varieties of seizures. As a rule, levetiracetam or valproic acid is used - such medications are equally effective, as in absences, and in myoclonic or tonic-clonic paroxysms. If there is a combination of absence and tonic-clonic seizures, then it is appropriate to appoint Lamotrigine.
• In atypical absence, monotherapy is performed with valproic acid, Lamotrigine, Phenytoin. Sometimes there is a need to connect steroid drugs. It is undesirable to use Tiagabine, Carbamazepine, Phenobarbital, because of the possibility of increased symptoms.
• When monotherapy is ineffective, a number of drugs are used. As a rule, anticonvulsant medications combine among themselves, taking into account the individual characteristics of the patient and the disease.

The dosage of the selected anticonvulsant is gradually reduced, up to and including cancellation, but only in the case of stable remission for 2-3 years. If repeated episodes of epilepsy are found, then the main pathology is treated, against the background of symptomatic therapy.

If the cognitive side suffers, then a psychologist is required to be treated.

Help with absences

At absense, there is a short depression of consciousness, and it develops unpredictably. It is believed that in most cases, such moments occur almost imperceptibly for others, because the attack lasts no more than a few seconds.

Absence looks like a short pause in motor and speech activity. Mostly, the patient does not need any specific help. The only thing on which to concentrate all attention is the safety of the patient. In no case can you leave a person alone, until consciousness is restored to its fullest.

Is it possible to distract the child from absence?

There is such a thing as false absense - it is a "fading", "looping" at one point, which disappears if the patient is called, touched, or simply clapped his hands. This absense can not be stopped by such measures, therefore it is believed that it will not be possible to distract a person from a true attack.

It will not work and prevent the attack, since it usually begins suddenly and unpredictably.

Since the absence does not last long, you should not try to influence the patient in any way - the attack will end on its own, just as it began.

Prevention

Full preventive maintenance of absence is to eliminate any moments that can provoke an attack. So, it is necessary to prevent the development of stresses, psycho-emotional situations, fears in advance. The emergence of conflicts and disputes should be minimized.

It is equally important to devote less time to a TV or computer. In return, you should rest more (active rest is welcomed), it's good to get enough sleep.

In addition, you need to protect your health, prevent the occurrence of injuries and inflammatory processes.

There is no specific prevention of absences.

[44], [45]

Forecast

Absenses are considered benign pathologies, because 80% of patients after a time there is a stable remission - of course, if the patient was provided with timely medical assistance, and a full course of treatment was performed.

In individual cases, single seizures are repeated at an older age. This condition requires additional anti-relapse treatment, against the background of compliance with the rules of their own safety. Until the complete relief of seizures, such people do not have the right to drive a car, work with any mechanisms.

As for the general development of children suffering from absences, it does not differ from that of other peers. Of course, in some cases, there is a lack of physical or intellectual development, but these are only single variants, and only under the condition of a malignant course of the disease.

And yet, we must not forget that frequent repeated seizures can lead to certain problems with the concentration of attention in the child. The suffering kid can become closed, inattentive, and this will sooner or later affect the quality of study. Therefore, children diagnosed with "absence" should be monitored not only by the doctor, but also by educators and educators.

[46], [47]