Affective respiratory seizures in children

Among the manifestations of syncopal conditions in pediatric neurology, attacks of short-term reflexive breath holding are noted - affective-respiratory attacks.

According to ICD-10, they have the code R06 and are classified as symptoms without any specific diagnosis.

Such pauses in breathing during inhalation or exhalation are often called episodic apnea syndrome (absence of breathing) in children, anoxic seizures, expiratory apnea, as well as vagal attacks caused by an affective reaction that are etiologically unrelated to epilepsy.

In general, this symptom is quite common, but, as doctors say, very difficult.

Epidemiology

Statistics on affective-respiratory attacks cited in various sources show different frequencies of cases of this condition, apparently due to the lack of precise clinical data.

According to some data, the frequency of such attacks in healthy children aged from six months to one and a half to two years is 0.1-4.7%; according to other data - 11-17% and even more than 25%, although recurring attacks are recorded only in a fifth of this number, with convulsions - up to 15%, and with fainting - less than 2%.

In approximately 20-30% of cases, one of the child's parents suffered from affective-respiratory attacks in early childhood.

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Causes affective-respiratory seizures.

Currently, the key causes of affective-respiratory attacks in children from six months to four or five years of age are seen in the fact that many structures of the central nervous system (CNS) in early childhood are characterized by functional immaturity with a lack of clear coordination in their work and an autonomic nervous system (ANS) that is not fully adapted.

First of all, this is due to the ongoing myelination of nerve fibers after birth. Thus, in children, the spinal cord and its roots are completely covered with a myelin sheath only by the age of three, the vagus (wandering nerve) is myelinated by the age of four, and the fibers of the CNS conduction pathways (including the axons of the pyramidal tract of the medulla oblongata) - by the age of five. But the tone of the vagus nerve stabilizes much later, and, probably, this is why affective-respiratory attacks in newborns occur quite rarely, and in such cases they can be a sign of congenital Arnold-Chiari anomaly or genetically determined and inherited Rett syndrome and Riley-Day syndrome.

The medulla oblongata and its respiratory center, which supports the reflex automatism of the movement of the respiratory muscles, are well developed in children and perform their functions from the moment the child is born, however, the vasomotor center located here does not always ensure the adequacy of vasomotor reactions.

In early childhood, the sympathetic and parasympathetic divisions of the ANS, which provide respiratory and all other unconditioned reflexes, continue to improve. At the same time, the number of synapses transmitting nerve impulses increases rapidly, and the excitation of neurons is not yet adequately balanced by their inhibition, since the synthesis of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter of the central nervous system, is insufficient in the subcortex of the child's brain. Due to these features, the cerebral cortex can be subject to both direct and reflected diffuse overexcitation, which experts explain not only the increased nervous excitability of many young children, but also their emotional lability.

It should be noted that, unlike foreign doctors, many domestic pediatricians equate affective-respiratory attacks in children with hysterical seizures or self-resolving hysterical paroxysms, that is, in essence, with manifestations of hysterical neurosis.

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Risk factors

The main risk factors or triggers for affective-respiratory attacks in children are: sudden fear, unexpected severe pain, for example, when falling, as well as violent expression of negative emotions, nervous tension or stressful shock.

Psychologists have recognized the significant importance of parents' reactions to manifestations of strong emotions, irritability or discontent in children. It should be borne in mind that the tendency to such attacks, as well as to many other syncopal states, can be transmitted genetically - along with the type of the autonomic nervous system (hypersympathicotonic or vagotonic).

Neurologists consider the predisposing factors to be the particularities of the central nervous system and the autonomic nervous system in early childhood, which contribute to high nervous excitability and hypertonicity of the sympathetic part of the autonomic nervous system, which is especially active in stressful situations. Excessive reactivity of individual structures of the limbic system also plays a role, in particular, the hypothalamus, which controls the work of the autonomic nervous system, and the hippocampus, which regulates emotions, in the brain.

In addition, possible factors that can provoke respiratory arrest when a child cries include iron deficiency anemia in children.

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Pathogenesis

Neurophysiologists continue to elucidate the pathogenesis of affective-respiratory attacks, but emphasize its unconditional connection with age-related features of the central nervous system and, to a greater extent, the functioning of the autonomic nervous system.

During an affective-respiratory attack that occurs in a screaming and crying child against the background of fear, pain or an uncontrolled explosion of negative emotions, there is a reflex suppression of the respiratory center of the medulla oblongata due to hyperoxygenation or hyperoxia - a significant increase in the level of oxygen in the blood and an increase in its partial pressure (which is the result of frequent deep breathing during crying or screaming) and a decrease in the volume of carbon dioxide in the blood (hypocapnia).

Schematically, the mechanism of development of affective-respiratory attacks looks like this. A short-term but sharp change in the ratio of oxygen and carbon dioxide in the blood is recorded by chemoreceptors and osmotic receptors of the carotid sinus - a special reflexogenic zone localized on the internal carotid artery. Chemical and barometric signals are converted into nerve impulses perceived by the vagus nerve, which participates in breathing, innervating the pharynx and larynx, and controls the pulse rate.

Next, the impulses are sent to the neurons of the muscle fibers of the pharynx and larynx, and they immediately react reflexively with a spasm that prevents inhalation, blocking the respiratory muscles, and provokes apnea. At the same time, the pressure inside the chest increases; bradycardia develops - the pulse slows down; a strong reflected signal coming from the brain through the vagus nerve causes asystole: within 5-35 seconds, the heart actually stops beating.

The cardiac output (the amount of blood ejected during systole) also decreases, and, accordingly, so does the arterial pressure and blood flow to the brain. Also, the blood stagnates in the veins, and the blood in the arteries loses oxygen (hypoxemia is observed), causing the child to turn pale and begin to lose consciousness.

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Symptoms affective-respiratory seizures.

Clinical symptoms of affective-respiratory attacks depend on their type

A simple attack of temporary cessation of breathing passes spontaneously - very quickly, without pathological external manifestations and a postictal state.

The second type of attacks – cyanotic (or blue) – occurs during affective expression of negative emotions, accompanied by screaming. Breathing is deep but intermittent, and its short-term cessation occurs at the moment of the next inhalation, which leads to blueness of the skin – cyanosis. This is followed by a sharp decrease in blood pressure, loss of muscle tone, but syncope and involuntary muscle contractions (convulsions) are rare. The child returns to normal within one or two minutes without any negative consequences for the cerebral structures, as evidenced by the electroencephalography readings.

In the third type, known as a pale affective-respiratory attack (most often caused by crying from sudden pain or severe fright), the first signs are a delay in breathing on exhalation and a decrease in heart rate. The child turns pale and may lose consciousness, and tonic-clonic seizures often occur. The usual duration of a pale attack does not exceed one minute, the child is lethargic after the attack and may fall asleep.

The fourth type is distinguished as complicated, since the mechanism of its development and symptoms include signs of cyanotic and pale types of affective-respiratory attacks.

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Complications and consequences

Experts claim that affective-respiratory attacks do not have consequences and complications: the brain structures or the psyche are not affected.

True, as long-term clinical practice shows, two out of ten children with a hypersympathicotonic or vagotonic type of the autonomic nervous system, suffering from attacks of short-term reflexive breath holding, may have similar attacks (syncope states) in adulthood.

Undesirable consequences are possible when parents consider children with these paroxysms to be sick, taking care of them and spoiling them in every possible way. Such tactics open a direct path to the formation of a neurasthenic and the development of hysterical neurosis.

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Diagnostics affective-respiratory seizures.

Pediatricians should refer the patient to a pediatric neurologist, since diagnosing affective-respiratory attacks is their profile.

To determine this condition, one consultation is not enough. After all, it is necessary to distinguish it from epilepsy, acute respiratory failure (in particular, mechanical asphyxia), asthmatic attacks, hysterical neurosis, vasovagal syncope, laryngospasm (and other forms of spasmophilia), episodic apnea of cardiogenic nature (in most cases associated with congenital weakness of the sinus node) and Cheyne-Stokes breathing (characteristic of increased intracranial pressure, pathologies of the cerebral hemispheres and cerebral tumors).

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Differential diagnosis

Epilepsy is particularly often misdiagnosed, so differential diagnostics are carried out, including:

• blood tests for hemoglobin levels, as well as gas components;
• instrumental diagnostics (electroencephalography, electrocardiography, hardware visualization of brain structures – ultrasound, MRI).

Treatment affective-respiratory seizures.

There is no need to prescribe treatment for affective-respiratory attacks. Firstly, no one knows how to treat them yet. Secondly, children outgrow these attacks by the age of six – as the nerve fibers are covered with a myelin sheath, the structures of the brain and central nervous system mature, and the functions of the autonomic nervous system improve. But parents should have comprehensive information about this condition.

However, if such attacks occur frequently (in some children, several times a day), then certain medications may be prescribed.

For example, a drug with calcium hopantenic acid - Pantogam (Pantocalcin, Gopat, Cognum) is a neuroprotective nootropic that promotes the resistance of the brain to hypoxia, reduces the excitability of the central nervous system (including seizures) and at the same time stimulates the formation of neurons. Therefore, the main indications for its use are: epilepsy, mental retardation, schizophrenia, severe hyperkinesia, TBI. This drug is taken orally, the dosage is determined by the doctor and depends on the frequency of affective-respiratory attacks and their intensity.

The parenterally administered nootropic and neuroprotective agent Cortexin increases the resistance of the central nervous system and brain to stressful situations. It is used in the complex therapy of epilepsy, cerebral palsy, cerebral circulation pathologies (including TBI) and VNS functions, as well as intellectual and psychomotor development disorders in children.

For all types of affective-respiratory attacks, it is recommended to take vitamins: C, B1, B6, B12, as well as calcium and iron preparations.

Forecast

Affective-respiratory attacks in children by the age of six or seven years pass, so the prognosis for this condition is determined as positive. The main thing is not to mistake such attacks for epilepsy and not to "treat" the child with strong drugs.

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