The space is local and unevenly expanded. Signs of expansion of the subarachnoid space of the brain and therapeutic actions

The subarachnoid space is a cavity between the arachnoid and pia mater of the brain and spinal cord. This space is filled with cerebrospinal fluid or cerebrospinal fluid. The fluid is involved in protecting and nourishing the brain.

What is the subarachnoid space? The subarachnoid space contains up to one hundred and forty milliliters of cerebrospinal fluid, which flows from the brain through the openings in the fourth ventricle.
Its maximum is contained in the cisterns of space, which are located above the large fissures and grooves of the brain.

The subarachnoid space is divided by the dentate ligaments and the cervical septum, which fix it.

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Reason for expansion of the subarachnoid space

Local expansions of the subarachnoid space are a signal of disturbances in the normal circulation of cerebrospinal fluid. This may be a consequence of injuries, tumors, or infectious diseases of the central nervous system. Undoubtedly, such a condition requires direct consultation with a neurologist or neurosurgeon and appropriate examinations.

The fact is that quite often the expansion of the subarachnoid space is a symptom of hydrocephalus or increased intracranial pressure.

The set of signs of external benign hydrocephalus in children of the first year of life is an increase in the subarachnoid spaces, which is most noticeable in the zone of the poles of the frontal lobes, while the ventricles of the brain can be only slightly dilated or have normal sizes. Moreover, the contents of these spaces have dense cerebrospinal fluid, which is observed on MRI, CT, and neurosonography. If it is benign hydrocephalus, then in most cases it resolves by two years of age.

Expansion of the subarachnoid space

The expansion of the subarachnoid spaces occurs in conjunction with an increase in head circumference and protrusion of the fontanelles, and a delay in the timing of their closure.

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A noticeable expansion of the subarachnoid space may also indicate arachnoiditis or leptomeningitis, in which the soft and arachnoid membranes of the brain become inflamed. This may be the result of injury, infection, or a number of other influences. This pathology is detected using ultrasound.

The cause of arachnoiditis can also be chronic intoxication, for example, lead, alcohol, arsenic, reactive inflammation with slowly developing tumors and encephalitis.

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General symptoms of arachnoiditis:

headache that is worse early in the morning, sometimes accompanied by nausea and vomiting,
dizziness,
general fatigue
irritability,
sleep disturbance.

The main thing in treatment is to eliminate the source of infection, for example, sinusitis or otitis media. For this purpose, antibiotics are prescribed in therapeutic doses.

Regarding the patient's life, the prognosis is usually favorable; only arachnoiditis of the posterior cranial fossa with occlusive hydrocephalus is dangerous.

The convexital subarachnoid space is unevenly and moderately expanded. The expansion of the subarachnoid space indicates a violation of the circulation of cerebrospinal fluid.

The space between the arachnoid (arachnoid) and soft membranes is called subarachnoid. In places where such adhesions are absent, expansions are formed - the so-called cisterns.

Changes in size and pressure in the subarachnoid space are often a sign of an inflammatory process or tumor.

In particular, a temporary change in the size of the cerebrospinal fluid circulatory system is possible with reactive cerebral edema and a decrease in intracranial space due to a hematoma or abscess.

The degree of manifestation of symptoms depends on the severity of development and on how dilated the subarachnoid space is. In children, expansion of the subarachnoid space is most often observed with hydrocephalus and arachnoiditis.

In adults, tumors and inflammatory processes of the subarachnoid space are more common. The expansion of the subarachnoid space is easily determined using instrumental examinations, the sequence of which is determined by the underlying disease.

But in no case should you rely on chance - if there is a symptom of expansion of the subarachnoid space, the child should be examined by specialists and appropriate treatment prescribed.

Moreover, the contents of these spaces have dense cerebrospinal fluid, which is observed on MRI, CT, and neurosonography.

After the concussion, the child was diagnosed with an expansion of the subarachnoid space by 1 mm, that is, a mild degree; the only symptoms were headache. I was treated with antibiotics and now everything is fine.

Ultrasound and neurosonography showed that the subarachnoid space was moderately expanded by 2.4 mm. everything else is normal. Development corresponds to age.

The effect of atrophic hydrocephalus on the subarachnoid space

No focal or diffuse changes were detected in the brain substance.

Doctor's answer: Hello! MRI is one of the functional diagnostic methods that helps a neurologist in making a diagnosis; the clinical method still remains the leading one.

Lacunar cyst in the area of the basal structures on the right, more likely as a consequence of the expanded perivascular Vikhrov-Robin space. The perivascular spaces are expanded.

In open schizencephaly, the edges of the cleft are separated, and cerebrospinal fluid fills it from the lateral ventricle to the subarachnoid space.

The subarachnoid space of the frontal region is expanded. In the area of dysplasia, the subarachnoid spaces are locally dilated, and abnormally dilated venous vessels are usually located there.

The convolutions in this area are wide, the adjacent subarachnoid space is expanded.

Subarachnoid space: causes, symptoms and diagnosis of its expansion

True porencephaly (schizencephaly) is always congenital and involves the existence of clefts in the brain substance that connect the ventricle and the subarachnoid space. On CT and MRI images there is an area of cerebrospinal fluid density (signal intensity) associated with the ventricle and (or) subarachnoid space.

Their choroid plexuses are the main source of cerebrospinal fluid production into the subarachnoid space. The mechanism for the development of such changes is quite simple. The inflammatory process (usually arachnoiditis or meningitis) increases the production of cerebrospinal fluid, which gradually stretches the subarachnoid space.

Subarachnoid space and its significance

The expansion of the subarachnoid space leads to an increase in cerebrospinal fluid pressure, which has relatively characteristic symptoms. Most often this occurs from excessive amounts of it entering the cavity, that is, hydrocephalus or hydrocephalus.

The subarachnoid space is expanded. What is it and what does it mean?

With a favorable course of the disease, the ventricles of the brain may remain within normal limits or be only slightly dilated.

Medical consultation Subarachnoid space

Treatment, as a rule, consists of eliminating the cause of the expansion of the subarachnoid space - increased intracranial pressure or infection caused by sinusitis or otitis media.

The expansion of the subarachnoid spaces occurs in conjunction with an increase in head circumference and protrusion of the fontanelles, and a delay in the timing of their closure. How serious is this expansion and what is it? Our doctors don’t say anything, how serious is everything in our case?

There is a slight expansion of the main and inferior retrocerebellar cisterns due to hypoplasia of the caudal parts of the cerebellar vermis. Doctor's response: Hello! Conclusion: MR picture of moderately severe external replacement hydrocephalus.

In the subarachnoid space there is 120-140 ml of cerebrospinal fluid flowing from the ventricular system of the brain through the foramina of Magendie and Luschka in the fourth ventricle.

Nature has reliably protected the brain and spinal cord. They are surrounded by several shells. Directly adjacent to the brain is a soft membrane of connective tissue. At some distance from it there is another shell, formed by connective tissue and whose structure resembles a fine network, for which it received the name arachnoid (arachnoid). The space between these membranes is called subarachnoid. The subarachnoid space is filled with cerebrospinal fluid (CSF). The total amount of cerebrospinal fluid ranges from 120 to 140 ml. Above the large grooves and fissures of the brain there are cisterns - areas where the amount of cerebrospinal fluid is especially large. The cerebrospinal fluid comes from the ventricles of the brain, and the outgrowths of the arachnoid membrane absorb it. Impaired circulation leads to expansion of the subarachnoid space.

Reasons for expansion of the subarachnoid space in adults

Poor circulation of cerebrospinal fluid is always associated with some pathological process affecting the brain. This could be a traumatic brain injury, a brain tumor, a stroke, or an infectious brain disease (for example, meningoencephalitis). All these traumatic factors trigger the process of atrophy, the amount of gray and white matter decreases, which leads to expansion of the subarachnoid space. There are three degrees of severity of this disorder: mild - expansion by 1-2 mm, moderate - by 3-4 mm and severe - more 4 mm. Possible clinical manifestations are impoverishment of mental activity, as well as pseudobulbar syndrome, characterized by a triad of symptoms: speech impairment caused by paralysis of the muscles involved in articulation, loss of sonority of the voice (speech becomes whispered) and impaired swallowing. Headaches and blurred vision are also possible due to congestion in the fundus. Timely treatment, including surgery, allows such patients to return to a full life. Even if it is not possible to achieve full work adaptation, a person can at least do without outside help in everyday activities.

Expansion of the subarachnoid space in infants

In infants, the cause of expansion of the subarachnoid space, as a rule, is increased intracranial pressure, birth trauma, or an infection that affects the brain as a result of complications of otitis media or a runny nose. The diagnosis is made according to neurosonographic studies. Often the prognosis is favorable: by the age of two, the subarachnoid space and ventricles of the brain return to normal on their own, and the child seems to “outgrow” the disease. But you shouldn't count on it. This disorder threatens the child with developmental delays, so it must be treated. Treatment is prescribed by a neurologist. It includes B vitamins and other drugs, as well as antibiotics if the disease was caused by an infection.

It is a rather complex structure. It, like the human heart, is constantly working. To function properly, this complex system must have a good blood supply and nutrient supply. This “nutritious” role for the brain is played by its membranes, which not only maintain homeostasis, but also protect against injuries, various bacteria and viruses. There are three membranes of the brain - hard, arachnoid and soft.

Subarachnoid space and its significance

The space between the arachnoid (arachnoid) and soft membranes is called subarachnoid.

The arachnoid membrane surrounds the brain and is covered with endothelium. It is connected to the hard and soft membranes by supra- and subarachnoid connective tissue membranes. Its outer surface is not fused with the hard shell, but in some places so-called granulations depart from it, which penetrate deep into the latter and, together with it, onto the inner surface of the cranial bones or into the sinuses, which ensures the resorption of fluid into the venous system. The inner surface of the arachnoid membrane is connected to a soft, thin membrane. In places where such adhesions are absent, expansions are formed - the so-called cisterns.

The environment where cerebrospinal fluid circulates consists of the ventricular system and the subarachnoid space of the brain and spinal cord. The ventricular system is formed from 4 reservoirs - two lateral, third and fourth.

Their choroid plexuses are the main source of cerebrospinal fluid production into the subarachnoid space. The norm for children is on average 80-120 ml, and for adults - from 120 to 160 ml per day, and it is completely renewed 3-5 times.

Circulation cerebrospinal fluid

The circulation of cerebrospinal fluid is a rather complex process.

It constantly flows from the lateral ventricles through the interventricular foramen to
the third, and then to the fourth ventricle. From the latter, through the median and lateral openings, the liquor enters the large tank. Then it moves to the basal and washes the subarachnoid convexital spaces of both hemispheres, after which it goes to the spinal cord. Eventually the fluid returns to the brain, where it is absorbed by the dural venous system. In general, the functions of the cerebrospinal fluid are very important. Cerebrospinal fluid performs the function of protecting the brain from injury and regulating internal pressure, and plays an excretory, immunological and transport role.

Expansion of the subarachnoid space and its causes

Changes in size and pressure in the subarachnoid space are often a sign of an inflammatory process or tumor.

The mechanism for the development of such changes is quite simple. The inflammatory process (usually arachnoiditis or meningitis) increases the production of cerebrospinal fluid, which gradually stretches the subarachnoid space. During the tumor process, a mechanical barrier is created to the outflow of cerebrospinal fluid, which is a consequence of a local increase in pressure and the formation of expansions in a certain area of the ventricular system of the brain. However, other options are possible that can lead to expansion of the subarachnoid space. In particular, a temporary change in the size of the cerebrospinal fluid circulatory system is possible with reactive cerebral edema and a decrease in intracranial space due to a hematoma or abscess.

Symptoms of expansion of the subarachnoid space

The expansion of the subarachnoid space leads to an increase in cerebrospinal fluid pressure, which has relatively characteristic symptoms.

Patients note a stubborn, persistent headache with symptoms of nausea and fountain-like vomiting, increased sensitivity to visual and auditory stimuli, and dizziness. The degree of manifestation of symptoms depends on the severity of development and on how dilated the subarachnoid space is. In children, expansion of the subarachnoid space is most often observed with hydrocephalus and arachnoiditis. Much less often, birth trauma or developmental defects of the nervous system become the causes of this complication.

In adults, tumors and inflammatory processes of the subarachnoid space are more common. Hydrocephalus is extremely rare and most often develops after a brain injury.

Diagnostics

The expansion of the subarachnoid space is easily determined using
instrumental examinations, the sequence of which is determined by the underlying disease. Echoencephalography is performed more often in children and makes it possible to see the displacement of the brain relative to the bones of the skull under the pressure of the cerebrospinal fluid. CT and magnetic resonance imaging are mostly used for adults. The latest methods make it possible to establish the layer-by-layer structure of the brain and the nature of tumor growth, and, in combination with the results of a lumbar puncture, determine the treatment tactics for inflammatory diseases.

The cavity between the membranes of the spinal cord - soft and arachnoid - filled with cerebrospinal fluid is called the subarachnoid space. Ligaments that fix the position of the spinal cord pass through this space.

The pathways for cerebrospinal fluid consist of the subarachnoid spaces of the spinal cord and brain and the ventricular system. The ventricles of the brain, whose function is to produce cerebrospinal fluid, are lined with epithelium of various types - cubic and cylindrical. Under normal conditions, they hold less cerebrospinal fluid than the subarachnoid spaces. The walls of the ventricles are quite strong and inflexible, and the subarachnoid spaces change their volume under the influence of various factors.

Liquor plays the role of a shock absorber - it protects the brain from traumatic influences, performs a transport role and immunological functions.

The subarachnoid space of the brain and spinal cord have direct communication with the ventricles of the brain, forming a series of communicating vessels. The outer part of the arachnoid spaces is divided by membranes. This structure forms separate chambers and tanks.

CSF pressure increases briefly with changes in functional states - heavy physical work, stress, even with emotional disorders. With injuries, inflammatory processes of the central nervous system and cancer, its increase increases, which leads to expansion of the subarachnoid space.

Expansion of the subarachnoid space in infants

The subarachnoid convexital spaces in infants expand as the head grows - it increases in circumference. Parents may notice a pathological process by the protrusion of the fontanelles - places of the skull where the bones of the skull converged so that the child could pass through the birth canal without hindrance.

Also, in infants, expansion of the interhemispheric fissure and subarachnoid space is accompanied by a rapid increase in the skull, which leads to the fact that the child cannot raise his head. In this case, a diagnosis is made of perinatal encephalopathy. In addition to the general impairment of the condition, a decrease in reflex function, children become capricious, refuse to eat, lag behind their peers physiologically, and lose weight.

There is another very indicative symptom - “moon gaze”. The eyelids of sick babies are constantly drooping and part of the white is visible from under the skin - the pupil and iris roll under the eyelids. With minor brain lesions, this look appears periodically; with severe lesions, the iris can be seen for a short time.

In children, brain atrophy may also occur, in which expansion of the convexital subarachnoid spaces occurs. The furrows in the frontal, parietal, temporal and occipital regions increase.

The ventricular system is also pathologically deformed due to expansion. In this case, serious examinations are carried out only in the second year of life - earlier, diagnostic measures are considered dangerous to the baby’s life.

Not only computer and tomographic studies may be required, but also the extraction of cerebrospinal fluid using a puncture.

At an early age, children undergo neurosonography - the condition of the cranial cavity can be examined using this method only before the fontanelles fusion.

If a significant area is damaged or leukomalacia is diagnosed - this term refers to softening of the brain, a condition when functional abilities are impaired, impulse signals in the required volume are not sent or received - in the future the child will lag behind in development.

But you shouldn't panic. The child’s body has a great chance of recovery; with timely and adequate treatment – when the first symptoms appear – the chances of recovery increase.

What does moderate expansion of the subarachnoid space in adults indicate?

Expansion of the subarachnoid convexital spaces – uneven or uniform – cannot occur without reason. Impaired circulation of the cerebrospinal fluid is always caused by pathological processes of an inflammatory or traumatic nature, which negatively affect the general condition, cause the ventricles of the brain to spasm, and lead to the expansion of the interhemispheric fissure.

Factors causing this change:

congenital pathologies of the liquor-conducting system;
traumatic brain injuries of varying severity;
infectious diseases – encephalitis and meningitis of various etiologies;
oncological processes of the brain - arachnoendotheliomas, meningiomas and the like.

In these diseases, brain volume increases due to edema, but functional cells of the gray and white matter of the brain atrophy due to increased intracranial pressure.

The amount of cerebrospinal fluid increases, the pattern of convolutions of the cerebral cortex is smoothed out, the subarachnoid space first expands slightly, and then the pathological changes increase.

If treatment is neglected - leaving the victim in a helpless state - then physiological vital activity will not recover on its own, and death is possible. But even with adequate treatment, some brain functions will be lost to a significant extent.

The expansion of convexital spaces is progressing.

There are 3 degrees of severity of such changes:

light, insignificant – up to 2 mm;
average – from 2 to 4 mm;
severe – more than 4 mm.

Symptoms of intracranial disorders: changes in mental activity, sensory and motor disorders, pseudobulbar syndrome.

Pseudobulbar syndrome is a condition during which speech is simultaneously impaired - the functions of sound reproduction are lost, words can only be pronounced in a whisper, and swallowing becomes difficult. This is due to the fact that an uneven change in the position of the hemispheres and their compression leads to disruption of the activity of the cortical centers innervating the muscles of the pharynx and larynx, which leads to paralysis or paresis of the muscles of the larynx.

Surgical treatment does not always help victims; complete adaptation to work and life is practically impossible to achieve. However, with timely treatment, it is possible to restore a person’s ability to perform daily activities – when caring for himself – without outside help. In some cases, thinking abilities and intellectual qualities are preserved.