Affective respiratory attacks in children

Among the manifestations of syncopic conditions in children's neurology are seizures of short-term reflex respiration delay - affective-respiratory attacks.

According to ICD-10, they have the code R06 with reference to symptoms without specifying any precise diagnosis.

Such respiratory arrest at the time of inspiration or expiration is often called the syndrome of episodic apnea (lack of breathing) in children, anoxic seizures, expiratory apnea, and etiologically unrelated to epilepsy vagal attacks due to affective reaction.

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

Epidemiology

The statistics of affective-respiratory seizures in different sources show a different frequency of cases of this condition, evidently due to the lack of accurate clinical data.

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

Approximately 20-30% of cases of affective-respiratory attacks in early childhood suffered one of the parents of the child.

[1], [2],

Causes of the affective-respiratory attacks

Currently, the key causes of affective-respiratory attacks in children from six months to four to 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 not fully adapted the autonomic nervous system (VNS).

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

The oblong brain and its respiratory center, which supports the reflex automatism of the movement of the respiratory muscles, is well developed in children, and performs its functions from the moment the baby appears to light, but the vasomotor center located here does not always ensure the adequacy of vasomotor reactions.

In early childhood, the sympathetic and parasympathetic departments of the VNS continue to improve, providing respiratory and all other unconditioned reflexes. At the same time, the number of nerve impulses of synapses is rapidly increasing, and the excitation of neurons is not 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 children's brain. Due to these features, the cortex of the large hemispheres can be subjected to both direct and reflected diffuse overexcitation, than the specialists explain not only the increased nervous excitability of many young children, but also their  emotional lability.

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

[3], [4], [5]

Risk factors

The main risk factors or triggers for affective-respiratory seizures in children: sudden fear, sudden severe pain, for example, when falling, as well as rapid expression of negative emotions, nervous overexertion or stressful shock.

Psychologists recognized the importance of the parents' reaction to manifestations of strong emotions, irritability or discontent of children. It should be borne in mind that the propensity to similar attacks, as well as to many other syncopal conditions, can be transmitted genetically - together with the type of autonomic nervous system (hypersympathicotonic or vagotonic).

In neurologists, predisposing factors are all the same features of the central nervous system and VNS during early childhood, contributing to high nervous excitability and hypertonicity of the sympathetic part of the autonomic nervous system, which is particularly active in stressful situations. The excessive reactivity of the individual structures of the limbic system also plays a role, in particular, controlling the work of the VNS of the hypothalamus and the regulating emotion of the hippocampus of the brain.

In addition, the possible factors that, when crying in a child can provoke a delay in breathing, include  iron deficiency anemia in children.

[6], [7],

Pathogenesis

Neurophysiology continues to elucidate the pathogenesis of affective-respiratory attacks, but emphasizes its unconditional connection with the age-related features of the central nervous system and, to a greater extent, the functioning of the ANS.

In an affective-respiratory attack that occurs in a screaming and crying child against a background of fright, pain, or an uncontrolled explosion of negative emotions, reflex inhibition of the respiratory center of the medulla oblongata occurs due to hyperoxygenation or hyperoxia-a significant increase in the oxygen level in the blood and an increase in its partial pressure is the result of frequent deep breathing when crying or crying) 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 fixed by chemoreceptors and osmotic receptors of the carotid sinus - a special reflexogenic zone located on the internal carotid artery. The chemical and barometric signals are transformed into nerve impulses, perceived by the vagus nerve, which participates in breathing, innervating the pharynx and larynx, and controls the pulse rate.

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

Also, the minute volume of the heart (the amount of blood ejected during systole) and, accordingly, blood pressure and blood flow to the brain are reduced. Also, blood stagnates in the veins, and blood in the arteries loses oxygen (hypoxemia is noted), causing the child to pale and begin to lose consciousness.

[8]

Symptoms of the affective-respiratory attacks

The 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 postictal conditions.

The second type of attacks - cyanotic (or blue) - occurs when the affective expression of negative emotions, accompanied by a cry. Breathing is deep, but intermittent, and its short-term stoppage occurs at the time of another inhalation, which leads to cyanosis of the skin - cyanosis. Then follows a sharp decrease in blood pressure, a loss of muscle tone, but syncope and muscle contractions of an involuntary nature (convulsions) are rare. The child comes to a normal state within one to two minutes without any negative consequences for the cerebral structures, as evidenced by electroencephalography.

In the third type, known as a pale affective-respiratory attack (most commonly occurring when crying from sudden pain or violent fright), the first signs are manifested by a delay in breathing during exhalation and a decrease in the heart rate. The child pales and can lose consciousness, often there are cramps of tonic-clonic type. The usual duration of a pallor attack does not exceed one minute, the child after the attack is sluggish, and he can fall asleep.

The fourth type is isolated as complicated, since in the mechanism of its development and symptomatology there are signs of cyanotic and pale types of affective-respiratory attacks.

[9]

Complications and consequences

Experts argue that affective-respiratory attacks have no consequences and complications: brain structures or psyche are not affected.

However, as shown by many years of clinical practice, two out of ten children with hypersympaticotonic or vagotonic type of autonomic nervous system, suffering from seizures of short-term reflex delay in breathing, similar attacks (syncopic conditions) may be in adulthood.

Unwanted consequences are possible when children with paroxysms, parents are considered sick, in every way guarding and pampering them. Such tactics open a direct path to the formation of a neurasthenic and the development of a hysterical neurosis.

[10], [11], [12], [13], [14], [15]

Diagnostics of the affective-respiratory attacks

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

To determine this state of one consultation is not enough. 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 a cardiogenic nature (in most cases associated with congenital weakness of the sinus node) and Cheyne-Stokes respiration (characteristic of increased intracranial pressure, pathologies of the cerebral hemispheres and cerebral tumors).

[16], [17], [18]

Differential diagnosis

Especially often, epilepsy is mistakenly diagnosed, therefore, differential diagnosis is carried out, including:

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

Treatment of the affective-respiratory attacks

The need to prescribe treatment of affective-respiratory attacks is absent. First, while no one knows how to treat them. Secondly, children these seizures by the age of six grow out - as the nerve fibers cover the myelin sheath, the maturation of brain structures and the central nervous system, and improve the functions of the ANS. But parents should have comprehensive information on this condition.

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

For example, the drug with calcium gopantene gopanthenic acid -  Pantogam  (Pantokaltsin, Gopat, Kogum) refers to neuroprotective nootropics that promote brain resistance to hypoxia, reduces the excitability of the central nervous system (including convulsions) and at the same time stimulates the formation of neurons. Therefore, the main indications for its use: epilepsy, oligophrenia, schizophrenia, pronounced 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 nootropic and neuroprotective agent Cortexin improves the stability of the central nervous system and brain to stressful situations. It is used in the complex therapy of epilepsy, cerebral palsy, pathologies of cerebral circulation (including with CCT) and functions of the VNS, as well as violations of the intellectual and psychomotor development of children.

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

Forecast

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

[19], [20], [21]