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Quite often, after birth, babies have enlarged ventricles of the brain. This condition does not always mean the presence of a disease that necessarily requires treatment.

Ventricular system of the brain

The ventricles of the brain are several interconnected collectors in which the formation and distribution of liquor fluid occurs. Liquor washes the brain and spinal cord. Normally, there is always a certain amount of cerebrospinal fluid in the ventricles.

Two large collectors of cerebrospinal fluid are located on either side of the corpus callosum. Both ventricles are connected to each other. On the left side is the first ventricle, and on the right is the second. They consist of horns and a body. The lateral ventricles are connected through a system of small holes to the 3rd ventricle.

In the distal part of the brain, between the cerebellum and the medulla oblongata, there is the 4th ventricle. It is quite large in size. The fourth ventricle is diamond-shaped. At the very bottom there is a hole called the diamond-shaped fossa.

Proper functioning of the ventricles allows cerebrospinal fluid to enter the subarachnoid space when necessary. This zone is located between the dura mater and the arachnoid membrane of the brain. This ability allows you to maintain the required volume of cerebrospinal fluid in various pathological conditions.

In newborn babies, dilatation of the lateral ventricles is often observed. In this condition, the horns of the ventricles are enlarged, and increased accumulation of fluid in the area of ​​their bodies may also be observed. This condition often causes both left and right ventricle enlargement. In differential diagnosis, asymmetry in the area of ​​the main brain collectors is excluded.

The size of the ventricles is normal

In infants, the ventricles are often dilated. This condition does not at all mean that the child is seriously ill. The dimensions of each ventricle have specific values. These indicators are shown in the table.

To assess normal indicators, the determination of all structural elements of the lateral ventricles is also used. The lateral cisterns should be less than 4 mm deep, the anterior horns between 2 and 4 mm, and the occipital horns between 10 and 15 mm.

Causes of enlarged ventricles

Premature babies may have dilated ventricles immediately after birth. They are located symmetrically. Symptoms of intracranial hypertension in a child with this condition usually do not occur. If only one of the horns increases slightly, then this may be evidence of the presence of pathology.

The following reasons lead to the development of ventricular enlargement:

Fetal hypoxia, anatomical defects in the structure of the placenta, development of placental insufficiency. Such conditions lead to disruption of the blood supply to the brain of the unborn child, which can cause expansion of the intracranial collectors.

Traumatic brain injuries or falls. In this case, the outflow of cerebrospinal fluid is disrupted. This condition causes water to stagnate in the ventricles, which can lead to symptoms of increased intracranial pressure.

Pathological birth. Traumatic injuries, as well as unforeseen circumstances during childbirth, can lead to disruption of the blood supply to the brain. These emergency conditions often contribute to the development of ventricular dilatation.

Infection with bacterial infections during pregnancy. Pathogenic microorganisms easily penetrate the placenta and can cause various complications in the child.

Prolonged labor. Too long a time between the rupture of amniotic fluid and the expulsion of the baby can lead to the development of intrapartum hypoxia, which causes a disruption in the outflow of cerebrospinal fluid from the dilated ventricles.

Oncological formations and cysts that are located in the brain. The growth of tumors puts excess pressure on intracerebral structures. This leads to the development of pathological expansion of the ventricles.

Foreign bodies and elements which are located in the brain.

Infectious diseases. Many bacteria and viruses easily penetrate the blood-brain barrier. This contributes to the development of numerous pathological formations in the brain.

Fetal hypoxia

Traumatic brain injuries or falls

Pathological birth

Bacterial infections during pregnancy

Oncological formations and cysts that are located in the brain

Infectious diseases

How does it manifest?

Ventricular dilatation does not always lead to adverse symptoms. In most cases, the child does not experience any discomfort that would indicate the presence of a pathological process.

Only with pronounced disturbances do the first adverse manifestations of the disease begin to occur. These include:

Gait disturbance. Babies begin to walk on tiptoes or step on their heels.

The appearance of visual disturbances. They often manifest themselves in children in the form of squint or insufficient focusing on various objects. In some cases, a child may experience double vision, which worsens when looking at small objects.

Trembling of hands and feet.

Behavioral disorders. Babies become more lethargic and drowsy. In some cases, even apathetic. It is very difficult to captivate a child with any games or recreational activities.

Headache. It appears when intracranial pressure increases. At the height of pain, vomiting may occur.

Dizziness.

Decreased appetite. Babies in the first months of life refuse to breastfeed and eat poorly. In some cases, the baby spits up more.

Sleep disturbance. Babies may have difficulty falling asleep. Some children walk in their sleep.

The disease can vary in severity. With minimal symptoms, they speak of a mild course. When headache, dizziness, and other symptoms indicating high intracranial hypertension appear, the disease becomes moderately severe. If the child’s general condition is severely disturbed and treatment in a hospital setting is required, then the disease becomes more severe.

Consequences

Late diagnosis of pathological conditions that lead to the appearance of enlargements in the area of ​​the ventricles of the brain can affect the further development of the child. The first persistent symptoms of ventricular dilatation are observed in babies at 6 months.

Impaired outflow of liquor fluid can lead to a persistent increase in intracranial pressure. In severe cases of the disease, this contributes to the development of disturbances of consciousness. Visual and hearing disorders lead to the development of hearing loss and weakened vision in the child. Some children experience epileptic seizures and seizures.

Diagnostics

In order to determine the exact size of the ventricles, as well as find out their depth, doctors prescribe several examination methods.

The most informative and reliable are:

Ultrasonography . Allows you to accurately describe the quantitative indicators of the ventricles, as well as calculate the ventricular index. Using ultrasound, you can estimate the volume of liquor fluid that is present in the brain collectors during the study.

CT scan. With high accuracy it allows you to describe the structure and size of all ventricles of the brain. The procedure is safe and does not cause pain in the baby.

Magnetic resonance imaging. It is used in complex diagnostic cases when establishing a diagnosis is difficult. Suitable for older children who are able to remain still throughout the examination. In young children, MRI is performed under general anesthesia.

Fundus examination.

Neurosonography.

Ultrasonography

CT scan

Magnetic resonance imaging

Fundus examination

Neurosonography

Treatment

Treatment of pathological conditions that lead to dilatation and asymmetry of the ventricles of the brain is usually carried out by a neurologist. In some cases, when the cause of the disease is space-occupying formations or the consequences of traumatic brain injuries, a neurosurgeon is involved.

To eliminate pathological symptoms, the following treatment methods are used:

Prescribing diuretics. Diuretics help reduce the manifestations of intracranial hypertension and improve the baby’s well-being. They also help normalize the formation of cerebrospinal fluid.

Nootropics. They improve brain function and also promote good blood supply to blood vessels.

Medicines with a sedative effect. Used to eliminate increased anxiety and agitation.

Potassium preparations. Positively affects urine excretion. This helps reduce the increased amount of cerebrospinal fluid in the body.

Multivitamin complexes. They are used to compensate for all the necessary microelements involved in vital processes. They also help strengthen the body and promote better resistance to disease.

Soothing and relaxing massage. Allows you to reduce muscle tone and also helps to relax the nervous system.

Physiotherapy. Helps normalize the outflow of liquor fluid and prevents its stagnation in the cerebral ventricles.

Prescribing antibacterial or antiviral drugs according to indications. They are used only in cases where the cause of the disease is viruses or bacteria. Appointed for a course appointment.

Surgery. It is used in the presence of various space-occupying formations or to remove fragments of bone tissue as a result of a skull fracture due to traumatic brain injury.

Forecast

If the condition develops in infancy and early infancy, the course of the disease is usually favorable. With appropriate treatment, all discomfort symptoms quickly disappear and do not bother the baby. High intracranial pressure is normalized.

In older children, the prognosis of the disease is somewhat different. Adverse symptoms are much more difficult to treat. A long course of the disease can lead to permanent visual and hearing impairment. If treatment was not started in a timely manner, then in most cases the child experiences persistent disorders that negatively affect his mental and mental development.

Dr. Komarovsky will talk about the expansion of the ventricles of the brain in infants and its consequences.

This article will be relevant for parents whose children have been diagnosed with ventricular enlargement

The ventricles are a system of anastomizing cavities that communicate with the spinal cord canal.

The human brain contains structures that contain cerebrospinal fluid (CSF). These structures are the largest in the ventricular system.

They can be divided into the following types:

• Lateral;
• Third;
• Fourth.

The lateral ventricles are designed to store cerebrospinal fluid. Compared to the third and fourth, they are the largest among them. On the left side there is a ventricle, which can be called the first, on the right side - the second. Both ventricles work with the third ventricle.

The ventricle, called the fourth, is one of the most important formations. The fourth ventricle contains the spinal canal. It appears to be diamond-shaped.

• Decreased appetite of the child; it often happens that the child refuses breastfeeding.
• Muscle tone is reduced.
• Tremors of the upper and lower extremities appear.
• A distinct manifestation of veins on the forehead, the cause is from the cranial cavity.
• The child's swallowing and grasping abilities are reduced.
• High likelihood of developing strabismus.
• Disproportionality of the head.
• Frequent regurgitation due to increased cerebrospinal fluid pressure.

A characteristic sign of ventricular enlargement and the development of hypertensive-hydrocephalic syndrome (HHS) manifests itself in a headache that begins in the morning on the left or right. Often the baby feels sick and vomits.

The child often complains of the inability to raise his eyes and lower his head, dizziness and weakness appear, and the skin begins to turn pale.

Diagnostic methods

It is very difficult to determine whether a baby’s ventricle is enlarged. Diagnostics does not provide a 100% guarantee that the diagnosis can be determined, even using the latest methods.

Closing of the fontanelles occurs in, after which the change in the size of the cerebrospinal fluid is monitored.

The following types of diagnostics include the following:

1. Magnetic resonance imaging. It identifies problems in the soft tissue structures of the child’s brain quite well.
2. The condition of the fundus is assessed for the presence of edema or hemorrhage.
3. Neurosonography. It is carried out to determine the size of the ventricles (both left and right).
4. Lumbar puncture.
5. CT scan.

The problem with diagnosing a newborn using MRI is that the baby needs to lie quietly for about 20-25 minutes. Since this task is almost impossible for a baby, doctors have to put the child into artificial sleep. At the same time, this procedure is carried out

Therefore, most often, computed tomography is used to diagnose the size of the ventricles of the brain. At the same time, the quality of diagnosis is slightly lower than using MRI.

A violation is considered if the ventricles of the brain have a norm different from 1 to 4 mm.

Treatment

Enlarged ventricles are not always a reason to sound the alarm. When the ventricles of the brain are enlarged, this may be a case of individual and physiological development of the baby’s brain system. For example, for large babies this is the norm.

Also, in the treatment of this disease the following will be ineffective: acupuncture, herbal treatment, homeopathy, therapy with vitamins.

First of all, in the treatment of dilation of the lateral ventricles in a child is to prevent the development of possible complications in the child.

Possible consequences of HGS

The hypertensive-hydrocephalic condition often causes a number of serious complications, these include:

• Falling into a coma;
• Development of complete or partial blindness;
• Deafness;
• Death.

Ventricular enlargement in newborns, as a diagnosis, has a higher chance of a favorable outcome than in older children, due to increased arterial and intracranial pressure, which returns to normal as they grow older.

The expansion of the lateral ventricles of the brain has adverse consequences and primarily depends on the cause of the development of the HGS.

Video

Conclusion

Dilatation in newborns should not be considered an anomaly in the development of the baby. It is rare that serious medical assistance is required. A complete and final diagnosis, which will be established by a qualified specialist - a neurologist, will reflect the complete picture of the disease.

Therefore, observation and consultation with a specialist are necessary so that your child does not suffer any complications.

Why is an ultrasound of the baby's brain performed?

The discovery of the ability of ultrasound to reflect differently from structures of different densities was made 200 years ago, but in pediatrics this diagnostic method has become in demand since the mid-20th century.

Ultrasonic waves are produced using piezoelectric crystals. Sound vibrations with a frequency of 0.5 - 15 MHz tend to penetrate through soft tissue, encountering structures with different acoustic characteristics.

Sometimes the sound is reflected as an echo, hence another name for the procedure - echography. While inferior to cutting-edge techniques, ultrasound has its advantages:

• Does not harm tissues, the fetus, chromosomes, has no contraindications or side effects;
• Does not require special preparation or administration of anesthesia for examination;
• Available at a very early age;
• Doesn't take much time;
• A simple procedure can be repeated more than once;
• It is tolerated by children without problems.

Why is an ultrasound of the brain performed on infants? Research using the properties of sound vibrations is one of the most informative ways to study the structure of an infant’s brain, on which both the effectiveness and timing of treatment completely depend.

Neurosonography

A study of the brain that reveals the limits of midbrain structures, displacements, additional cavities of the brain, dilatation of the ventricles, blood flow speed and changes in the vessels supplying the brain using ultrasound is called neurosonography (NSG).

The method helps diagnose a tumor, brain abscess, intracranial hemorrhage, underdevelopment, dropsy and cerebral edema, complications from intrauterine infections.

By examining vessels and blood flow speed using ultrasound, it is possible to identify an area of ​​ischemia (lack of blood circulation), infarction (cell damage due to weak blood flow).

For infants, ultrasound plays a special role, since the fontanelles ─ areas free from the bones of the skull ─ remain on the baby’s head for up to 1-1.5 years.

Without craniotomy at this age, one can easily penetrate these “windows” to examine information about the functioning of the brain.

The size of the fontanelle also determines the possibilities for studying areas of the brain.

A simple and accessible method makes it possible to use neurosonography during mass screening examinations of infants for early detection of pathologies in brain function. In some maternity hospitals, the procedure is performed on all newborns, but this method has not yet become mandatory.

Premature babies, as well as those born in difficult conditions, are referred to ultrasound by neurologists. Why do infants undergo a brain ultrasound, you can learn from Dr. Komarovsky.

Preparation for the NSG

Access to examine the baby's head is possible only through the fontanel - a membrane between the bones of the skull, with the help of which the fetus, moving along the birth canal, adapts to the anatomical features of the mother's body. As intracranial pressure increases, excessive volume is released through the fontanelles.

In a full-term baby, by the time of birth, most of the fontanels are overgrown with hard tissues; only the largest one can be determined by touch - normally soft, pulsating, located at the level of the skull bones, sometimes even small.

In the first three months, while the fontanelles are available, NSG is performed. The interpretation of the results is not affected by the child’s condition: whether he is sleeping or awake, crying or calm.

There is one limitation for Doppler ultrasound, which examines the blood vessels of the brain: the procedure is carried out 1.5 hours after eating. In other cases, no special preparation is needed. Where to do an ultrasound of the brain in a baby ?

You can check the address with your pediatrician, call or use the 24-hour electronic appointment form with a doctor on the medical institution’s website.

Read here. How do seizures manifest in infants?

Indications for NSG

• The birth of a baby before the 36th week of pregnancy;
• Birth weight ─ up to 2 kg 800 g;
• Degree of difficulty of childbirth ─ 7/7 points or less on the Apgar scale ─ (possible damage to the central nervous system with developmental defects: ear shape, number of fingers);
• Hernia (protruding part of the brain with a membrane);
• Lack of cry at birth;
• Transfer due to birth trauma to intensive care;
• Prolonged or rapid labor;
• Intrauterine infection;
• Absence of labor after water breaks due to conflicting Rh factor;
• During an ultrasound examination of a pregnant woman, brain pathology in the fetus was visible;
• 1 month after cesarean section;
• Use of auxiliary instruments during childbirth (forceps, vacuum extractor, etc.);
• Non-standard head shape;
• Birth injury;
• For strabismus, convulsions, torticollis, paresis, paralysis.

If the baby’s capricious behavior, constant regurgitation, tearfulness, if no pathology is found in other organs, an ultrasound of the head is prescribed. The effectiveness of treatment for meningitis, encephalitis, genetic disorders, and head trauma is monitored by ultrasound.

Hemorrhage, cysts, ischemia, hydrocephalus, and intracerebral abscess are also diagnosed by ultrasound.

How does the procedure work?

An ultrasound is performed through the fontanelles; if it is necessary to study the structure of the posterior cranial cavity, then through the back of the head. When laying the baby on the couch, a sensor lubricated with a conductor gel is installed on the temples (if there are still springs) and in the area of ​​the large spring.

Sometimes the back of the head is also examined.

By adjusting the position of the sensor, the doctor examines the structures of the brain.

Children do not feel pain, the study lasts no more than 10 minutes.

An echography image is projected on the display screen. Dense fabrics are highlighted in light tones, loose ones - in darker tones.

Typically, sonometry of 12 brain parameters is performed. The measurements are compared with standards, and the specialist gives an opinion on whether the ultrasound scan of the baby’s brain is normal.

This is not a diagnosis yet, just a diagnostic tool for a neurologist. In case of serious deviations, clarifying studies are carried out (MRI, CT).

Interpretation of NSG results

The norms for ultrasound of a baby are determined by the timing of his birth. But there are also mandatory criteria for deciphering an ultrasound of the brain in an infant:

• Symmetrical arrangement of all brain structures;
• All convolutions are clearly visible;
• The cerebral ventricles and cisterns are homogeneous in structure;
• The thalamus and subcortical nuclei have moderate echogenicity;
• Anterior horn of the lateral ventricle ─ 1-2 mm in length;
• Body of the lateral ventricle ─ 4 mm in depth;
• The interhemispheric fissure (up to 2 mm in width) does not contain fluid;
• The choroid plexuses are hyperechoic;
• 3rd ventricle ─ 2-4mm;
• Large tank ─ 3-6mm;
• Without displacement of stem structures.

After the study, the doctor deciphers and describes the results. For this he has 12 normative criteria.

He evaluates the size and contours of the ventricles (this helps to diagnose rickets, hydrocephalus and other pathologies). Then the condition of large vessels is studied (this helps to identify cysts and hemorrhages).

Dimensions and contours of the cerebral ventricles

Normally, the ventricles are cavities filled with cerebrospinal fluid. Enlargement of the ventricle may indicate hydrocephalus, an accumulation of cerebrospinal fluid in the skull.

The disease can be congenital or acquired. The cause of development may be intrauterine infection, defects in fetal development, or hemorrhage.

Children with this diagnosis are characterized by an increased head size, large fontanels and a convex forehead.

Enlargement of the subarachnoid space

This zone, filled with cerebrospinal fluid, is located between the soft and arachnoid membranes. Normally the width should be a few millimeters. If this area enlarges, you can think of inflammation of the membranes after injury or infection.

Cysts in the choroid plexuses

These neoplasms are visible on ultrasound even during pregnancy. They can develop in infants and children of the second year of life. Cysts also occur in adults.

• Subependymal cysts are located near the ventricular wall and develop after hypoxia and minor hemorrhage. They do not affect brain activity and do not require treatment.
• Arachnoid cysts are located in the arachnoid membrane. Critical sizes ─ from 3 cm. They already put pressure on the brain, causing epilepsy. Such a cyst does not resolve on its own.

Hemorrhages in the brain centers

Pathology occurs due to intrauterine infection, conflicting blood rhesus, and oxygen deficiency. birth injuries, blood clotting disorders. Occurs more often in premature infants.

Such hemorrhages come in four degrees of complexity. With this diagnosis, observation by a neurologist is mandatory, since the consequences of self-medication are very dangerous.

Ischemia

Oxygen deficiency during ischemia can lead to damage to nerve cells. Occurs after premature birth, when the lungs are not sufficiently developed by the time the baby is born.

Damage to nerve cells is accompanied by softening of the brain, which provokes disturbances in the development of the baby.

Meningitis

When the brain becomes infected, its membranes thicken and become inflamed. The disease requires immediate treatment.

Tumors

Volumetric neoplasms in the cranium are rare, which makes it all the more important to be under constant supervision of a neurologist.

If there are a significant number of “finds”, it is worth consulting with a doctor about prescribing vitamin D for your baby, which promotes rapid overgrowth of the fontanelles. This is not useful if there is increased intracranial pressure.

Consultations in such cases require timing or complete refusal of vaccinations. For closed springs, transcranial ultrasound is performed, which is less informative than NSG.

An MRI can give a clearer picture of the disease, but mandatory general anesthesia for a baby is not always justified. The price of an ultrasound scan of the brain in an infant can range from 1300 to 3800 rubles. The cost depends on the region where the examination is carried out: for Moscow it is 1,600 rubles. and above, ultrasound of the brain in infants in St. Petersburg ─ from 1000 rubles.

Conclusion

On thematic forums, parents are satisfied with the conditions of the examination. The only thing that scares them is the conclusions of sonologists.

But timely diagnosis significantly increases the chances of recovery, because the brain of an infant in the first year of life is immature, and the body’s capabilities at this age are great.

Parents need to study the list of indications in order to understand that inexplicable crying, whims, shuddering, convulsions are harmless “little things” that indicate a pathology that is difficult to identify with age and no less difficult to treat.

More information

Examination of the newborn’s brain is a mandatory procedure that allows us to identify various pathologies of the nervous system in the first days of life. However, it should be remembered that an increase in the size of the lateral ventricles of the brain does not always indicate serious neurological disorders.

The human central nervous system is very complex. Its most important centers are the brain and spinal cord. Any pathology and deviations from the norm can cause the development of a number of neurological disorders, so examination of the brain and spinal cord in newborns must be done in the first days of life.

Ultrasound of the brain is mandatory in the following cases:

• complicated childbirth;
• birth injury;
• fetal hypoxia;
• prematurity;
• presence of infections in the mother.

Also, a brain examination in newborns is indicated in the case of a low Apgar score (less than 7 points) and in case of changes in the fontanel.

If there are indications for an ultrasound scan of the brain, it is performed immediately after the birth of the baby; a repeat examination is indicated upon reaching one month of age.

There is a table describing brain norms for newborns. So, if during the initial ultrasound there is a discrepancy between the ventricles of the brain in children - the norm in the table is presented for different ages - additional examinations are carried out.

Dimensions of the lateral ventricles

If an ultrasound showed enlarged lateral ventricles in a child under one year old, this is not necessarily a pathology. For many children, their normal size may be slightly larger than normal, especially if the child has a large skull.

Control of brain development in a child is important here. The examination must be repeated regularly. If there is a tendency towards a further increase in the size of the ventricles, only then can we talk about pathology.

These organs serve as an intermediate “storage” for cerebrospinal fluid. With a significant increase in their size, the outflow of cerebrospinal fluid is disrupted in a child, intracranial pressure increases and there is a risk of developing hydrocephalus.

What does the expansion indicate?

Ultrasound of the brain is mandatory for children born. Enlargement and asymmetry of the lateral ventricles may indicate the presence of the following pathologies in a child:

• hydrocephalus;
• traumatic brain injury;
• cyst;
• pathologies of central nervous system development.

If there is an increase in a premature baby, expectant management is chosen. The examination must be carried out regularly to determine trends in changes in the size of the ventricles and the condition of the brain.

In most cases, deviation from the norm does not mean pathology. In premature infants, enlargement and asymmetry of the ventricles are associated with features of brain development. This problem goes away on its own without treatment when the child begins to catch up with his peers in weight.

It is not uncommon for premature babies to be born with a septum pellucida cyst. Such a cyst is a small, regular-shaped neoplasm filled with fluid. The cyst compresses neighboring tissues and blood vessels, which can cause disruption of the metabolic processes of the brain.

As a rule, in 90% of cases the cyst goes away on its own without treatment and does not cause any neurological disorders in the child.

Treatment is necessary if the cyst was not diagnosed at birth, but was obtained as a result of an illness or injury. In such cases, its size quickly increases and provokes the accumulation of cerebrospinal fluid, which can lead to the development of a number of disorders.

How and when is diagnosis carried out?

Regular ultrasound examination of the brain is prescribed in the first month of the baby’s life, if there are alarming symptoms, for example, weak reflexes or causeless restlessness of the child.

If pathology is present, the examination in children under one year of age is repeated every three months.

Deviation from the norm at this age does not always require treatment. A wait-and-see approach and regular examinations are required to determine the dynamics of changes in the condition of brain tissue. Often, enlarged ventricles are temporary and quickly return to normal without any treatment.

In case of complicated childbirth, ultrasound is performed in the first hours of life. In all other cases, a neurologist may refer you for examination if the child exhibits the following symptoms:

• head too big;
• weakening of reflexes;
• anxiety;
• fontanelle injuries;
• strabismus;
• elevated body temperature.

Also, diagnosis of the state of the brain is carried out in cases of suspected cerebral palsy, rickets and a number of other congenital disorders.

How is an ultrasound done on babies?

Ultrasound examination methods are the safest and do not have a negative effect on the newborn’s body.

No special preparations are required for the examination. The child should be fed and not feel discomfort. Since newborn babies spend most of their time sleeping, there is no need to wake the baby for examination. An ultrasound does not cause discomfort, so the child will not wake up unless specifically awakened.

The child is placed on a special couch, a small amount of special gel is applied to the fontanel area and the diagnosis begins. The procedure does not last long and does not cause any discomfort.

Decoding the results

The results of the examination are examined by a neurologist. Do not worry ahead of time if the results obtained show minor deviations from the norm. In addition to the size of the lateral ventricles, an important characteristic is their structure and symmetry. The doctor’s task is to assess not only the sizes, but also their compliance with the characteristics of the child’s body.

Dental granuloma is an inflammation of the tissue near the tooth root. The treatment is carried out by a dentist, an additional decoction is used

Dental granuloma is an inflammation of the tissue near the tooth root. The treatment is carried out by a dentist, an additional decoction is used

One of the causes of headaches and other brain disorders lies in the disruption of cerebrospinal fluid circulation. CSF is the cerebrospinal fluid (CSF) or cerebrospinal fluid (CSF) that constitutes the constant internal environment of the ventricles, the pathways through which cerebrospinal fluid passes, and the subarachnoid space of the brain.

Liquor, often an invisible part of the human body, performs a number of important functions:

• Maintaining a constant internal environment of the body
• Control of metabolic processes of the central nervous system (CNS) and brain tissue
• Mechanical support for the brain
• Regulation of the activity of the arteriovenous network by stabilizing intracranial pressure and
• Normalization of osmotic and oncotic pressure levels
• Bactericidal effect against foreign agents, due to the content in its composition of T- and B-lymphocytes, immunoglobulins responsible for immunity

The choroid plexus, located in the cerebral ventricles, is the starting point for the production of cerebrospinal fluid. Cerebrospinal fluid passes from the lateral ventricles of the brain through the foramen of Monro into the third ventricle.

The aqueduct of Sylvius serves as a bridge for the passage of cerebrospinal fluid into the fourth ventricle of the brain. After passing through several more anatomical formations, such as the foramen of Magendie and Luschka, the cerebellocerebral cistern, Sylvian fissure, enters the subarachnoid or subarachnoid space. This gap is located between the arachnoid and pia mater of the brain.

CSF production corresponds to a rate of approximately 0.37 ml/min or 20 ml/h, regardless of intracranial pressure. The general figures for the volume of cerebrospinal fluid in the cavity system of the skull and spine in a newborn child are 15-20 ml, a one-year-old child has 35 ml, and an adult has about 140-150 ml.

Within 24 hours, the cerebrospinal fluid is completely renewed 4 to 6 times, and therefore its production averages about 600-900 ml.

The high rate of formation of cerebrospinal fluid corresponds to the high rate of its absorption by the brain. Absorption of CSF occurs through pachyonic granulations - villi of the arachnoid membrane of the brain. The pressure inside the skull determines the fate of the cerebrospinal fluid - when it is reduced, its absorption stops, and when it is increased, on the contrary, it increases.

In addition to pressure, the absorption of cerebrospinal fluid also depends on the condition of the arachnoid villi themselves. Their compression, blockage of the ducts due to infectious processes, leads to a cessation of the flow of cerebrospinal fluid, disrupting its circulation and causing pathological conditions in the brain.

CSF spaces of the brain

The first information about the liquor system is associated with the name of Galen. The great Roman physician was the first to describe the membranes and ventricles of the brain, as well as the cerebrospinal fluid itself, which he took to be a kind of animal spirit. The cerebrospinal fluid system of the brain aroused interest again only many centuries later.

Scientists Monroe and Magendie wrote descriptions of the holes that describe the course of the CSF, which received their name. Domestic scientists also had a hand in contributing knowledge to the concept of the liquor system - Nagel, Pashkevich, Arendt. The concept of liquor spaces—cavities filled with liquor fluid—has appeared in science. Such spaces include:

• Subarachnoid - a slit-like cavity between the membranes of the brain - arachnoid and soft. The cranial and spinal spaces are distinguished. Depending on the location of part of the arachnoid membrane to the brain or spinal cord. The head cranial space contains about 30 ml of cerebrospinal fluid, and the spinal space contains about 80-90 ml
• Virchow-Robin spaces or perivascular spaces - a perivascular area that includes part of the arachnoid membrane
• The ventricular spaces are represented by the ventricular cavity. Disturbances of cerebrospinal fluid dynamics associated with ventricular spaces are characterized by the concept of monoventricular, biventricular, triventricular
• tetraventricular depending on the number of damaged ventricles;
• Cisterns of the brain - spaces in the form of extensions of the subarachnoid and soft membranes

Spaces, pathways, as well as cerebrospinal fluid producing cells are united by the concept of the cerebrospinal fluid system. Violation of any of its links can cause disorders of liquorodynamics or liquor circulation.

Liquorodynamic disorders and their causes

Emerging liquorodynamic disorders in the brain are classified as conditions in the body in which the formation, circulation and utilization of CSF are disrupted. The disorders can occur in the form of hypertensive and hypotensive disorders, with characteristic intense headaches. The causative factors of liquorodynamic disorders include congenital and acquired.

Among the congenital disorders, the main ones are:

• Arnold-Chiari malformation, which is accompanied by impaired outflow of cerebrospinal fluid
• Dandy-Walker malformation, which is caused by an imbalance in the production of cerebrospinal fluid between the lateral and third and fourth cerebral ventricle
• Stenosis of the cerebral aqueduct of primary or secondary origin, which leads to its narrowing, resulting in an obstruction to the passage of CSF;
• Agenesis of the corpus callosum
• Genetic disorders of the X chromosome
• Encephalocele is a cranial hernia that leads to compression of brain structures and disrupts the movement of cerebrospinal fluid
• Porencephalic cysts, which lead to hydrocephalus - water on the brain, obstructing the flow of cerebrospinal fluid

Among the acquired causes are:

Already in the period 18-20 weeks of pregnancy, one can judge the state of the baby’s cerebrospinal fluid system. Ultrasound at this stage allows you to determine the presence or absence of fetal brain pathology. Liquorodynamic disorders are divided into several types depending on:

• Course of the disease in the acute and chronic phases
• The stages of the disease are a progressive form, which combines the rapid development of abnormalities and an increase in intracranial pressure. Compensated form with stable intracranial pressure, but an expanded cerebral ventricular system. And subcompensated, which is characterized by an unstable condition, leading to liquorodynamic crises with minor provocations
• The locations of CSF in the brain cavity are intraventricular, caused by stagnation of cerebrospinal fluid inside the ventricles of the brain, subarachnoid, which encounters obstruction of CSF flow in the arachnoid membrane of the brain, and mixed, combining several different points of impaired cerebrospinal fluid flow
• The level of cerebrospinal fluid pressure on - hypertensive type, normotensive - with optimal indicators, but existing causative factors of liquor dynamics disorders and hypotensive, accompanied by low pressure inside the skull

Symptoms and diagnosis of liquorodynamic disorders

Depending on the age of the patient with impaired cerebrospinal fluid dynamics, symptoms vary. Newborn babies under one year of age suffer from:

• Frequent and profuse regurgitation
• Slow overgrowth of fontanelles. Increased intracranial pressure leads, instead of overgrowth, to swelling and intense pulsation of the large and small fontanels
• Rapid growth of the head, acquiring an unnatural elongated shape;
• Spontaneous crying without visible pain, which leads to lethargy and weakness of the child, his drowsiness
• Twitching of limbs, tremors of the chin, involuntary shudders
• A pronounced vascular network in the bridge of the child’s nose, on the temporal region, his neck and at the top of the chest, manifested in the tense state of the baby when crying, trying to raise his head or sit down
• Movement disorders in the form of spastic paralysis and paresis, more often lower paraplegia and less often hemiplegia with increased muscle tone and tendon reflexes
• Late onset of functioning of head holding ability, sitting and walking
• Convergent or divergent strabismus due to block of the oculomotor nerve

Children over one year of age begin to experience symptoms such as:

• Increased intracranial pressure, which leads to attacks of intense headache, often morning, accompanied by nausea or vomiting, which does not bring relief
• Rapid alternation of apathy and restlessness
• Coordination imbalance in movements, gait and speech in the form of its absence or difficulty in pronunciation
• Decreased visual function with horizontal nystagmus, as a result of which children cannot look up
• "Bobble Head Doll"
• Intellectual development disorders, which may have minimal or global severity. Children may not understand the meaning of the words they speak. With a high level of intelligence, children are talkative, prone to superficial humor, inappropriate use of loud phrases, due to difficulty understanding the meaning of words and mechanical repetition of words that are easy to remember. Such children have increased suggestibility, lack initiative, are unstable in mood, and are often in a state of euphoria, which can easily give way to anger or aggression
• Endocrine disorders with obesity, delayed sexual development
• Convulsive syndrome, which becomes more pronounced over the years

Adults more often suffer from liquorodynamic disorders in the hypertensive form, which manifests itself in the form of:

• High blood pressure numbers
• Severe headaches
• Periodic dizziness
• Nausea and vomiting that accompany headaches and do not bring relief to the patient
• Heart imbalance

Among the diagnostic studies for disorders in liquor dynamics, the following are distinguished:

• Examination of the fundus by an ophthalmologist
• MRI (magnetic resonance imaging) and CT () are methods that allow you to obtain an accurate and clear image of any structure
• Radionuclide cisternography, based on the study of brain cisterns filled with cerebrospinal fluid through labeled particles that can be tracked
• Neurosonography (NSG) is a safe, painless, time-consuming study that gives an idea of ​​the picture of the ventricles of the brain and the cerebrospinal fluid spaces.

The movement of cerebrospinal fluid is due to its continuous formation and resorption. The movement of cerebrospinal fluid occurs in the following direction: from the lateral ventricles, through the interventricular foramina into the third ventricle and from it through the cerebral aqueduct into the fourth ventricle, and from there through its median and lateral foramina into the cerebellar medullary cistern. The cerebrospinal fluid then moves up to the superolateral surface of the brain and down to the terminal ventricle and into the spinal cerebrospinal fluid canal. The linear circulation rate of the cerebrospinal fluid is about 0.3-0.5 mm/min, and the volumetric speed is between 0.2-0.7 ml/min. The causes of cerebrospinal fluid movement are heart contractions, breathing, body position and movements, and movements of the ciliated epithelium of the choroid plexuses.

CSF flows from the subarachnoid space into the subdural space, then is absorbed by the small veins of the dura mater.

Cerebrospinal fluid (CSF) is formed mainly due to ultrafiltration of blood plasma and the secretion of certain components in the choroid plexuses of the brain.

The blood-brain barrier (BBB) ​​is associated with the surface separating the brain and cerebrospinal fluid from the blood and providing bidirectional selective exchange of various molecules between the blood, cerebrospinal fluid and brain. The sealed contacts of the endothelium of the brain capillaries, epithelial cells of the choroid plexus and arachnoid membranes serve as the morphological basis of the barrier.

The term "barrier" indicates a state of impermeability to molecules of a certain critical size. Low molecular weight components of blood plasma, such as glucose, urea and creatinine, freely flow from plasma into the cerebrospinal fluid, while proteins pass through passive diffusion through the wall of the choroid plexus, and there is a significant gradient between plasma and cerebrospinal fluid, depending on the molecular weight of the proteins.

Limited permeability of the choroid plexus and the blood-brain barrier maintain normal homeostasis and composition of the cerebrospinal fluid.

Physiological significance of cerebrospinal fluid:

• cerebrospinal fluid performs the function of mechanical protection of the brain;
• excretory and so-called Sing function, i.e. the release of certain metabolites to prevent their accumulation in the brain;
• cerebrospinal fluid serves as a vehicle for various substances, especially biologically active ones, such as hormones, etc.;
• performs a stabilizing function:
• maintains an extremely stable brain environment, which should be relatively insensitive to rapid changes in blood composition;
• maintains a certain concentration of cations, anions and pH, which ensures normal excitability of neurons;
• performs the function of a specific protective immunobiological barrier.

Rules for receiving and delivering liquor to the laboratory

I.I.Mironova, L.A.Romanova, V.V.Dolgov
Russian Medical Academy of Postgraduate Education

To obtain cerebrospinal fluid, lumbar puncture is most often used, and less commonly, suboccipital puncture. Ventricular cerebrospinal fluid is usually obtained during surgery.

Lumbar puncture is carried out between the III and IV lumbar vertebrae (L 3 -L 4) along the Quincke line (the line connecting the highest parts of the crests of the two iliac bones). The puncture can also be performed between L 4 -L 5 ; L 5 -S 1 and between L 2 -L 3.

Suboccipital (cisternal) puncture is carried out between the base of the skull and the first cervical vertebra, at the height of the line connecting the mastoid processes.

Ventricular (ventricular) puncture- this is practically a surgical manipulation, performed in cases where other types of puncture are contraindicated or inappropriate. The anterior, posterior or lower horn of one of the lateral ventricles of the brain is punctured.

When performing a lumbar puncture, it is necessary to remove the first 3-5 drops of cerebrospinal fluid, which allows you to get rid of the admixture of “travel” blood that enters the first portion of cerebrospinal fluid as a result of damage by the needle to the blood vessels located in the area of ​​the epidural space. Then collect 3 portions (in exceptional cases two) into sterile glass or plastic tubes, close them tightly, indicate on each tube its serial number, first name, patronymic and last name of the patient, time of puncture, diagnosis and list of necessary studies. The cerebrospinal fluid collected in test tubes is delivered to the clinical diagnostic laboratory immediately.

Using a lumbar puncture, you can obtain 8-10 ml of cerebrospinal fluid in an adult without complications, in children, including young children - 5-7 ml, in infants - 2-3 ml.

The brain is a complex closed system protected by many structures and barriers. These protective supports carefully filter all material approaching the sinuous organ. However, such an energy-intensive system still needs to interact and maintain communication with the body, and the ventricles of the brain are one of the tools for ensuring such communication: these cavities contain cerebrospinal fluid, which supports the processes of metabolism, transport of hormones and removal of metabolic products. Anatomically, the ventricles of the brain are a derivative of the expansion of the central canal.

So, the answer to the question is what is he responsible for? the ventricle of the brain will be as follows: one of the main tasks of the cavities is the synthesis of cerebrospinal fluid. This cerebrospinal fluid serves as a shock absorber, that is, it provides mechanical protection for parts of the brain (protects against various types of injuries). Liquor, as a liquid, is in many ways similar to the structure of lymph. Like the latter, cerebrospinal fluid contains a huge amount of vitamins, hormones, minerals and brain nutrients (proteins, glucose, chlorine, sodium, potassium).

Different ventricles of the brain in an infant have different sizes.

Types of ventricles

Each part of the brain's central nervous system requires its own self-care, and therefore has its own storage facilities for spinal cerebrospinal fluid. Thus, the lateral stomachs (which include the first and second), third and fourth are distinguished. The entire ventricular organization has its own message system. Some (the fifth) are pathological formations.

Lateral ventricles – 1 and 2

The anatomy of the ventricle of the brain involves the structure of the anterior, inferior, posterior horn and the central part (body). These are the largest in the human brain and contain cerebrospinal fluid. The lateral ventricles are divided into the left - the first, and the right - the second. Thanks to Monroe's holes, the lateral cavities connect to the third ventricle of the brain.

The lateral ventricle of the brain and the nasal bulb as functional elements are closely interconnected, despite their relative anatomical distance. Their connection lies in the fact that between them there is, according to scientists, a short path along which pools of stem cells pass. Thus, the lateral stomach is a supplier of progenitor cells for other structures of the nervous system.

Speaking about this type of ventricles, it can be argued that the normal size of the ventricles of the brain in adults depends on their age, skull shape and somatotype.

In medicine, every cavity has its normal values. Lateral cavities are no exception. In newborns, the lateral ventricles of the brain normally have their own dimensions: the anterior horn is up to 2 mm, the central cavity is 4 mm. These dimensions are of great diagnostic importance when studying pathologies of the infant’s brain (hydrocephalus, a disease discussed below). One of the most effective methods for studying any cavity, including the cavities of the brain, is ultrasound. It can be used to determine both the pathological and normal size of the ventricles of the brain in children under one year of age.

3rd ventricle of the brain

The third cavity is located below the first two, and is at the level of the intermediate section
CNS between the visual thalamus. The 3rd ventricle communicates with the first and second through the foramina of Monroe, and with the cavity below (4th ventricle) through the aqueduct.

Normally, the size of the third ventricle of the brain changes with the growth of the fetus: in a newborn – up to 3 mm; 3 months – 3.3mm; in a one-year-old child – up to 6 mm. In addition, an indicator of the normal development of cavities is their symmetry. This stomach is also filled with cerebrospinal fluid, but its structure differs from the lateral ones: the cavity has 6 walls. The third ventricle is in close contact with.

4th ventricle of the brain

This structure, like the previous two, contains cerebrospinal fluid. It is located between the Sylvian water supply and the valve. The fluid in this cavity enters the subarachnoid space through several channels - two foramina of Luschko and one foramen of Magendie. The rhomboid fossa forms the bottom and is represented by the surfaces of the brain stem structures: the medulla oblongata and the pons.
Also, the fourth ventricle of the brain provides the foundation for the 12th, 11th, 10th, 9th, 8th, 7th, and 5th pairs of cranial nerves. These branches innervate the tongue, some internal organs, the pharynx, facial muscles and facial skin.

5th ventricle of the brain

In medical practice, the name “fifth ventricle of the brain” is used, but this term is not correct. By definition, the stomachs of the brain are a set of cavities interconnected by a system of messages (channels) filled with spinal cerebrospinal fluid. In this case: the structure called the 5th ventricle does not communicate with the ventricular system, and the correct name would be “cavity of the septum pellucida.” From this follows the answer to the question: how many ventricles in the brain: four (2 lateral, third and fourth).

This hollow structure is located between layers of transparent partition. It, however, also contains cerebrospinal fluid, which enters the “stomach” through pores. In most cases, the size of this structure does not correlate with the frequency of pathology, however, there is evidence that in patients with schizophrenia, stress disorders and people who have suffered a traumatic brain injury, this part of the nervous system is enlarged.

Choroid plexuses of the ventricles of the brain

As noted, the function of the abdominal system is the production of cerebrospinal fluid. But how is this liquid formed? The only brain structure that provides the synthesis of cerebrospinal fluid is the choroid plexus. These are small villous formations belonging to vertebrates.

The choroid plexus is a derivative of the pia mater. They contain a huge number of vessels and carry a large number of nerve endings.

Ventricular diseases

In case of suspicion, an important method for determining the organic state of the cavities is puncture of the ventricles of the brain in newborns.

Diseases of the ventricles of the brain include:

Ventriculomegaly– pathological expansion of cavities. Most often, such expansions occur in premature babies. The symptoms of this disease are varied and manifest themselves in the form of neurological and somatic symptoms.

Ventricular asymmetry(individual parts of the ventricles change in size). This pathology occurs due to an excessive amount of cerebral fluid. You should know that violation of the symmetry of cavities is not an independent disease - it is a consequence of another, more serious pathology, such as neuroinfections, massive contusion of the skull or tumor.

Hydrocephalus(fluid in the ventricles of the brain in newborns). This is a serious condition characterized by the excessive presence of cerebrospinal fluid in the gastric system of the brain. Such people are called hydrocephalus. The clinical manifestation of the disease is excessive volume of the child's head. The head becomes so large that it is impossible not to notice. In addition, the defining sign of pathology is the “sunset” symptom, when the eyes shift to the bottom. Instrumental diagnostic methods will show that the index of the lateral ventricles of the brain is higher than normal.

Pathological conditions choroid plexuses occur against the background of both infectious diseases (tuberculosis, meningitis) and tumors of various localizations. A common condition is cerebral vascular cyst. This disease can occur in both adults and children. The cause of cysts is often autoimmune disorders in the body.

Thus, the norm of the ventricles of the brain in newborns is an important component in the knowledge of a pediatrician or neonatologist, since knowledge of the norm allows one to determine pathology and find deviations in the early stages.

You can read more about the causes and symptoms of diseases of the cerebral cavity system in the article enlarged ventricles.

Cerebrospinal fluid (CSF, cerebrospinal fluid) is one of the humoral media of the body, which circulates in the ventricles of the brain, the central canal of the spinal cord, cerebrospinal fluid tracts and subarachnoid space * of the brain and spinal cord, and which ensures the maintenance of homeostasis with the implementation of protective, trophic , excretory, transport and regulatory functions (*subarachnoid space - the cavity between the soft [vascular] and arachnoid meninges of the brain and spinal cord).

It is recognized that CSF forms a hydrostatic cushion that protects the brain and spinal cord from mechanical stress. Some researchers use the term “cerebrospinal fluid system”, referring to the set of anatomical structures that provide secretion, circulation and outflow of CSF. The liquor system is closely connected with the circulatory system. CSF is formed in the choroidal choroid plexuses and flows back into the bloodstream. The choroid plexus of the ventricles of the brain, the vascular system of the brain, neuroglia and neurons take part in the formation of cerebrospinal fluid. In its composition, CSF is similar only to the endo- and perilymph of the inner ear and the aqueous humor of the eye, but differs significantly from the composition of blood plasma, so it cannot be considered a blood ultrafiltrate.

The choroidal plexuses of the brain develop from folds of the soft membrane, which, even in the embryonic period, are invaginated into the cerebral ventricles. The vascular epithelial (choroidal) plexuses are covered with ependyma. The blood vessels of these plexuses are intricately convoluted, which creates their large total surface area. The particularly differentiated integumentary epithelium of the vascular epithelial plexus produces and releases into the CSF a number of proteins that are necessary for the functioning of the brain, its development, as well as the transport of iron and some hormones. Hydrostatic pressure in the capillaries of the choroid plexus is increased compared to normal for capillaries (outside the brain), they look as if they are hyperemic. Therefore, tissue fluid is easily released from them (transudation). The proven mechanism for the production of cerebrospinal fluid is, along with the transudation of the liquid part of the blood plasma, active secretion. The glandular structure of the choroid plexuses of the brain, their abundant blood supply and the consumption of large amounts of oxygen by this tissue (almost twice as much as the cerebral cortex) is proof of their high functional activity. The amount of CSF production depends on reflex influences, the rate of cerebrospinal fluid resorption and pressure in the cerebrospinal fluid system. Humoral and mechanical influences also influence the formation of CSF.

The average rate of cerebrospinal fluid production in humans is 0.2 - 0.65 (0.36) ml/min. An adult secretes about 500 ml of cerebrospinal fluid per day. The amount of cerebrospinal fluid in all cerebrospinal fluid ducts in adults, according to many authors, is 125 - 150 ml, which corresponds to 10 - 14% of the mass of the brain. In the ventricles of the brain there is 25 - 30 ml (of which 20 - 30 ml in the lateral ventricles and 5 ml in the III and IV ventricles), in the subarachnoid cranial space - 30 ml, and in the spinal space - 70 - 80 ml. During the day, fluid can be exchanged 3-4 times in an adult and up to 6-8 times in young children. Accurate measurement of the amount of fluid in living subjects is extremely difficult, and measurement on corpses is also practically impossible, since after death the cerebrospinal fluid begins to be rapidly absorbed and after 2 - 3 days disappears from the ventricles of the brain. Apparently, therefore, data on the amount of cerebrospinal fluid in different sources vary greatly.

CSF circulates in the anatomical space, which includes internal and external receptacles. The internal container is the system of the ventricles of the brain, the aqueduct of Sylvius, and the central canal of the spinal cord. The external receptacle is the subarachnoid space of the spinal cord and brain. Both containers are connected to each other by the median and lateral openings (apertures) of the fourth ventricle, i.e. the foramen of Magendie (median aperture), located above the calamus scriptorius (a triangular depression at the bottom of the fourth ventricle of the brain in the area of ​​the lower angle of the rhomboid fossa), and the foramina of Luschka (lateral apertures), located in the region of the recessus (lateral pockets) of the fourth ventricle. Through the openings of the fourth ventricle, cerebrospinal fluid passes from the internal receptacle directly into the large cistern of the brain (cisterna magna or cisterna cerebellomedullaris). In the area of ​​the foramina of Magendie and Luschka there are valve devices that allow CSF to pass in only one direction - into the subarachnoid space.

Thus, the cavities of the internal receptacle communicate with each other and with the subarachnoid space, forming a series of communicating vessels. In turn, the leptomeninges (the combination of the arachnoid and pia mater, forming the subarachnoid space - the outer container of the cerebrospinal fluid) is closely connected with the brain tissue with the help of glia. When vessels are immersed from the surface of the brain into it, marginal glia are invaded along with the membranes, so perivascular clefts are formed. These perivascular fissures (Virchow-Robin spaces) are a continuation of the arachnoid bed; they accompany vessels that penetrate deeply into the substance of the brain. Consequently, along with the perineural and endoneural clefts of the peripheral nerves, there are also perivascular clefts, which form an intraparenchymal (intracerebral) container, which is of great functional importance. The cerebrospinal fluid flows through the intercellular gaps into the perivascular and pial spaces, and from there into the subarachnoid receptacles. Thus, washing the elements of the brain parenchyma and glia, the cerebrospinal fluid is the internal environment of the central nervous system in which the main metabolic processes take place.

The subarachnoid space is limited by the arachnoid and pia mater and is a continuous container surrounding the brain and spinal cord. This part of the cerebrospinal fluid ducts represents an extracerebral CSF reservoir, which is closely connected with the system of perivascular (periadventitial*) and extracellular slits of the pia mater of the brain and spinal cord and with the internal (ventricular) reservoir (*adventitia - the outer lining of the wall of a vein or artery).

In some places, mainly at the base of the brain, the significantly expanded subarachnoid space forms cisterns. The largest of them - the cistern of the cerebellum and medulla oblongata (cisterna cerebellomedullaris or cisterna magna) - is located between the anterior-inferior surface of the cerebellum and the posterolateral surface of the medulla oblongata. Its greatest depth is 15 - 20 mm, width 60 - 70 mm. Between the tonsils of the cerebellum, the foramen of Magendie opens into this cistern, and at the ends of the lateral projections of the fourth ventricle - the foramina of Luschka. Through these openings, cerebrospinal fluid flows from the lumen of the ventricle into the cistern magna.

The subarachnoid space in the spinal canal is divided into anterior and posterior sections by the dentate ligament, which connects the hard and soft membranes and fixes the spinal cord. The anterior section contains the exiting anterior roots of the spinal cord. The posterior section contains the incoming dorsal roots and is divided into left and right halves by the septum subarachnoidale posterius (posterior subarachnoid septum). In the lower part of the cervical and thoracic sections, the septum has a continuous structure, and in the upper part of the cervical, lower part of the lumbar and sacral sections of the spinal column it is weakly expressed. Its surface is covered with a layer of flat cells that perform the function of absorbing CSF; therefore, in the lower part of the thoracic and lumbar regions, the CSF pressure is several times lower than in the cervical region. P. Fontviller and S. Itkin (1947) established that the flow rate of CSF is 50 - 60 μ/sec. Weed (1915) found that circulation in the spinal space is almost 2 times slower than in the head subarachnoid space. These studies support the idea that the head part of the subarachnoid space is the main one in the exchange between CSF and venous blood, that is, the main outflow route. In the cervical part of the subarachnoid space there is a valve-shaped membrane of Retzius, which promotes the movement of cerebrospinal fluid from the skull into the spinal canal and prevents its reverse flow.

The internal (ventricular) reservoir is represented by the ventricles of the brain and the central spinal canal. The ventricular system includes two lateral ventricles located in the right and left hemispheres, the III and IV. The lateral ventricles are located deep in the brain. The cavity of the right and left lateral ventricles has a complex shape, because parts of the ventricles are located in all lobes of the hemispheres (except for the insula). Through paired interventricular foramina - foramen interventriculare - the lateral ventricles communicate with the third. The latter, through the aqueduct of the brain - aquneductus mesencephali (cerebri) or aqueduct of Sylvius - is connected with the IV ventricle. The fourth ventricle through 3 openings - the median aperture (apertura mediana - Mozhandi) and 2 lateral apertures (aperturae laterales - Lyushka) - connects to the subarachnoid space of the brain.

The CSF circulation can be schematically represented as follows: lateral ventricles - interventricular foramina - III ventricle - cerebral aqueduct - IV ventricle - median and lateral apertures - brain cisterns - subarachnoid space of the brain and spinal cord.

Liquor is formed at the highest speed in the lateral ventricles of the brain, creating maximum pressure in them, which in turn causes caudal movement of the fluid to the openings of the fourth ventricle. This is also facilitated by the wave-like beating of ependymal cells, which ensures the movement of fluid to the outlet openings of the ventricular system. In the ventricular reservoir, in addition to the secretion of cerebrospinal fluid by the choroid plexus, diffusion of fluid through the ependyma lining the cavities of the ventricles is possible, as well as reverse flow of fluid from the ventricles through the ependyma into the intercellular spaces, to the brain cells. Using the latest radioisotope techniques, it has been discovered that CSF is cleared from the ventricles of the brain within a few minutes, and then within 4 to 8 hours it moves from the cisterns of the base of the brain to the subarachnoid (subarachnoid) space.

M.A. Baron (1961) established that the subarachnoid space is not a homogeneous formation, but is differentiated into two systems - the system of cerebrospinal fluid channels and the system of subarachnoid cells. The canals are the main main channels for the movement of CSF. They represent a single network of tubes with shaped walls, their diameter ranges from 3 mm to 200 angstroms. Large canals communicate freely with the cisterns of the base of the brain; they extend to the surface of the cerebral hemispheres in the depths of the grooves. Gradually decreasing “gyral channels” extend from the “sulcus channels.” Some of these canals lie in the outer part of the subarachnoid space and are connected to the arachnoid membrane. The walls of the canals are formed by endothelium, which does not form a continuous layer. Holes in membranes can appear and disappear, as well as change their sizes, that is, the membrane apparatus has not only selective, but also variable permeability. The cells of the pia mater are arranged in many rows and resemble a honeycomb. Their walls are also formed by endothelium with holes. CSF may flow from cell to cell. This system communicates with the canal system.

1st path of CSF outflow into the venous bed. Currently, the prevailing opinion is that the main role in the removal of CSF belongs to the arachnoid (arachnoid) membrane of the brain and spinal cord. The outflow of cerebrospinal fluid mainly (30 - 40%) occurs through Pachionian granulations into the superior sagittal sinus, which is part of the venous system of the brain. Pachyon granulations (granulaticnes arachnoideales) are diverticula of the arachnoid membrane that arise with age and communicate with the subarachnoid cells. These villi pierce the dura mater and are in direct contact with the endothelium of the venous sinus. M.A. Baron (1961) convincingly proved that in humans they are the CSF outflow apparatus.

The sinuses of the dura mater are common collectors for the outflow of two humoral media - blood and CSF. The walls of the sinuses, formed by dense tissue of the dura mater, do not contain muscle elements and are lined from the inside with endothelium. Their lumen constantly gapes. In the sinuses there are trabeculae and membranes of various shapes, but there are no real valves, as a result of which changes in the direction of blood flow are possible in the sinuses. Venous sinuses drain blood from the brain, eyeball, middle ear, and dura mater. In addition, through diploetic veins and Santorini graduates - parietal (v. emissaria parietalis), mastoid (v. emissaria mastoidea), occipital (v. emissaria occipitalis) and others - the venous sinuses are connected with the veins of the cranial bones and soft integuments of the head and partially drain them.

The degree of outflow (filtration) of cerebrospinal fluid through pachyonic granulations is possibly determined by the difference in blood pressure in the superior sagittal sinus and CSF in the subarachnoid space. The cerebrospinal fluid pressure normally exceeds the venous pressure in the superior sagittal sinus by 15 - 50 mm of water. Art. In addition, the higher oncotic pressure of the blood (due to its proteins) should suck CSF containing little protein back into the blood. When the CSF pressure exceeds the pressure in the venous sinus, thin tubes in the pachyonic granulations open, allowing it to pass into the sinus. After the pressure equalizes, the lumen of the tubes closes. Thus, there is a slow circulation of CSF from the ventricles into the subarachnoid space and further into the venous sinuses.

2nd path of CSF outflow into the venous bed. The outflow of CSF also occurs through the cerebrospinal fluid channels into the subdural space, and then the cerebrospinal fluid enters the blood capillaries of the dura mater and is discharged into the venous system. Reshetilov V.I. (1983) showed, in an experiment with the introduction of a radioactive substance into the subarachnoid space of the spinal cord, the movement of cerebrospinal fluid predominantly from the subarachnoid to the subdural space and its resorption by the structures of the microcircular bed of the dura mater. The blood vessels of the dura mater of the brain form three networks. The internal network of capillaries is located under the endothelium, lining the surface of the dura mater facing the subdural space. This network is distinguished by significant density and in terms of development is much superior to the external network of capillaries. The internal network of capillaries is characterized by the short length of their arterial part and the much greater extent and looping of the venous part of the capillaries.

Experimental studies have established the main route of CSF outflow: from the subarachnoid space, fluid is directed through the arachnoid membrane into the subdural space and then into the internal network of capillaries of the dura mater. The release of CSF through the arachnoid membrane was observed under a microscope without the use of any indicators. The adaptability of the vascular system of the dura mater to the resorbing function of this shell is expressed in the maximum proximity of the capillaries to the spaces they drain. The more powerful development of the internal capillary network compared to the external network is explained by more intense resorption of SMEs compared to epidural fluid. In terms of permeability, the blood capillaries of the dura mater are similar to the highly permeable lymphatic vessels.

Other pathways for CSF outflow into the venous system. In addition to the described two main routes of CSF outflow into the venous bed, there are additional routes for the exit of cerebrospinal fluid: partially into the lymphatic system through the perineural spaces of the cranial and spinal nerves (from 5 to 30%); absorption of cerebrospinal fluid by ependymal cells of the ventricles and choroid plexuses into their veins (about 10%); resorption in the brain parenchyma mainly around the ventricles, in the intercellular spaces, in the presence of hydrostatic pressure and colloid-osmotic difference at the border of two media - cerebrospinal fluid and venous blood.

used materials from the article “Physiological justification of the cranial rhythm (analytical review)” part 1 (2015) and part 2 (2016), Yu.P. Potekhina, D.E. Mokhov, E.S. Tregubova; Nizhny Novgorod State Medical Academy. Nizhny Novgorod, Russia; St. Petersburg State University. Saint-Petersburg, Russia; Northwestern State Medical University named after. I.I. Mechnikov. St. Petersburg, Russia (parts of the article were published in the journal “Manual Therapy”)