Arachnoid cyst

An arachnoid cyst is a fluid-filled cavity lined with arachnoid cells. These formations are located between the surface of the brain and the arachnoid membrane.

An arachnoid cyst can be congenital or acquired. The latter occurs as a result of severe diseases, such as inflammation of the membranes of the brain and spinal cord, Marfan's disease, congenital complete or partial absence of the corpus callosum, as well as after surgical interventions. The walls of such cysts are covered with arachnoid scars.

According to statistics, such tumors are more often formed in males. They are usually located within the cerebrospinal fluid spaces containing numerous arachnoid membranes and increase their volume. Most often, arachnoid cysts are located in the part of the internal base of the skull formed by the sphenoid and temporal bones, outside the temporal lobes.

An arachnoid cyst of the brain is a hollow round formation filled with fluid, the walls of which consist of arachnoid cells. Such a formation is formed between the meninges and, when the cerebrospinal fluid contained inside the tumor presses on any part of the brain, it can cause symptoms such as dizziness, headache, ringing in the ears, etc. The larger the size of the cyst, the more pronounced the signs of the disease, up to the development of such serious disorders as deterioration of hearing and vision, speech and memory functions, seizures, etc.

Inflammatory processes, brain injuries, and an increase in the amount of fluid in the cyst can provoke tumor growth. Magnetic resonance imaging and computed tomography can diagnose the disease and determine the size and location of the tumor.

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Reasons

An arachnoid cyst may be a congenital pathology or develop as a result of injuries and severe diseases. The causes of arachnoid cysts of secondary origin may be associated with inflammation of the membranes of the spinal cord and brain, agenesis of the plexus of nerve fibers of the brain that unite the right and left hemispheres (corpus callosum), hereditary autosomal dominant disease of connective tissue (Marfan's disease), surgical interventions.

The main reasons for the growth of such formations may be an increase in the pressure of the intracavitary fluid, the development of inflammation of the membranes of the brain, and may also be associated with trauma, for example, with a concussion.

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Symptoms

The symptoms of an arachnoid cyst, as well as the degree of their expression, depend on the location and size of the neoplasm. As a rule, the symptoms of the disease appear before the age of twenty, and such tumors can also exist without any symptoms.

The main symptoms of arachnoid cyst formation include headaches, nausea, vomiting, impaired coordination of movements, partial paralysis of half of the body, hallucinations, seizures, and mental disorders.

Retrocerebellar cyst

There are several types of cysts that can form in the brain. The main ones are retrocerebellar, arachnoid cysts. When this type of tumor forms, fluid accumulates between the layers of the meninges, while when a retrocerebellar cyst develops, it forms inside the brain.

An arachnoid cyst is localized on the surface of the brain, while a retrocerebellar cyst is located in its space. As a rule, an arachnoid cyst occurs as a result of inflammatory processes in the meninges, hemorrhages, and brain trauma.

Retrocerebellar cyst is localized in the already affected area of the brain. To prevent damage to the entire brain, it is extremely important to identify the causes that led to the death of its area in time. Basically, this is insufficient cerebral blood supply, inflammatory processes of the brain, as well as intracranial surgical interventions.

Arachnoid cyst of the temporal lobe

An arachnoid cyst of the left temporal lobe may be asymptomatic or manifest itself in the form of such signs as:

• headache
• a feeling of pulsation and pressure in the head
• occurrence of noise in the left ear, not accompanied by hearing impairment
• hearing loss
• nausea
• vomiting reactions
• occurrence of convulsions
• problems with coordination of movements
• partial paralysis
• numbness of various parts of the body
• hallucinations
• mental disorders
• fainting

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Arachnoid cyst of the spine

An arachnoid cyst of the spine is a spherical cavity with liquid contents, the walls of which are lined with arachnoid cells. An arachnoid cyst of the spine is a benign formation that can cause pain in the lower back.

At the formation stage, the disease is asymptomatic. The first signs usually appear before the age of twenty. Since arachnoid cysts of the spine vary in size and location, differential diagnostics are often necessary to fully verify the presence of a cyst. In some cases, tumors resemble the symptoms of a herniated disc.

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Arachnoid cyst of the posterior cranial fossa

An arachnoid cyst of the posterior cranial fossa, according to the results of echography, is similar to a cyst formed in the case of an anomaly in the development of the cerebellum and the cerebrospinal fluid spaces located around it. The cerebellum occupies almost the entire posterior cranial fossa. When conducting differential diagnostics, the structure of the cerebellum is analyzed and, if there is a defect in its vermis, an arachnoid cyst of the posterior cranial fossa is excluded.

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Arachnoid cyst and cerebellar cyst

Arachnoid cyst and cerebellar cyst differ in structure and location.

A cerebellar cyst is a tumor that forms inside the brain and is a collection of fluid at the site of the affected area of the brain. To prevent further damage to the brain, the causes of such a pathology must be identified. Most often, intracerebral cysts occur as a result of cerebral circulatory disorders, strokes, injuries, inflammatory processes, and surgical interventions inside the skull.

Unlike an intracerebral cystic tumor, an arachnoid cyst is always localized on the surface of the brain, in the area of its membranes.

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Perineural arachnoid cyst

Perineural arachnoid cyst is localized in the spinal canal and is characterized by the accumulation of fluid in the area of the spinal cord root.

Most often, perineural cysts are located in the lumbar and sacral regions. The main causes of such formations include inflammatory processes and injuries. There are also cases of spontaneous occurrence of perineural cysts.

A cystic formation up to one and a half centimeters in size may not be accompanied by any symptoms and its detection is possible only during a preventive examination. As the tumor increases in size, it puts pressure on the spinal cord root in the area where it is localized. In this case, symptoms such as pain in the lumbar and sacral regions, lower extremities, a crawling sensation, as well as disturbances in the functioning of the pelvic organs and urinary system occur.

Differential diagnostics for suspected perineural cyst formation can be carried out with diseases such as intestinal colic, appendicitis, inflammation of the uterine appendages, and osteochondrosis.

The most accurate diagnostic methods for perineural cysts are computed tomography and magnetic resonance imaging. Such tumors are not detected by X-ray examination.

Treatment of a small perineural cyst can be conservative (not requiring surgical intervention). Surgery is indicated for severe cases of the disease that have a negative impact on the functioning of any organs. However, it should be noted that during surgical intervention there are risks such as spinal cord injury, adhesion formation, development of postoperative meningitis and recurrence of the tumor. The appropriateness of surgery is determined by the attending physician based on a general examination and accompanying symptoms.

Arachnoid cyst of the sylvian fissure

Arachnoid cyst of the Sylvian fissure is classified according to a number of characteristic features and can be of several types:

• small in size, usually bilateral, communicating with the subarachnoid space
• rectangular in shape, partially communicating with the subarachnoid space
• affecting the entire Sylvian fissure, not communicating with the subarachnoid space

Symptoms of a Sylvian fissure cyst include increased intracranial pressure, protrusion of the cranial bones, epileptic seizures, hydrocephalus due to compression of the ventricles of the brain, and visual impairment.

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Arachnoid cerebrospinal fluid cyst

An arachnoid cerebrospinal fluid cyst forms in the membrane of the brain and is a round cavity filled with liquid contents (cerebrospinal fluid). According to statistics, such neoplasms are more often found in males. The disease is usually diagnosed in adulthood, since at an earlier age the symptoms are not sufficiently expressed.

An arachnoid cerebrospinal fluid cyst can be congenital or acquired. The congenital form of this nosology is formed as a result of disturbances during the period of embryogenesis (embryonic development). The presumed cause of the occurrence of such a formation is fetal trauma during the development of the meninges. Such a formation can be detected during an ultrasound examination.

Acquired arachnoid cerebrospinal fluid cyst is the result of an inflammatory process in the membranes of the brain, trauma or hemorrhage in the brain.

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Arachnoid cyst of the parietal region

An arachnoid cyst of the parietal region is a benign volumetric neoplasm with a cavity filled with fluid similar to the cerebrospinal fluid. Tumors of this type can be a consequence of the development of inflammatory processes in the brain, as well as injuries. The consequence of such a neoplasm, if not treated in a timely manner, can be serious impairment of mental functions, memory, speech, as well as hearing and vision.

Depending on the indications, an arachnoid cyst of the parietal region can be removed endoscopically or surgically. As a rule, the indications for removal of such a formation are rapid growth and increase in the size of the tumor, the development of pronounced symptoms, and pressure of the neoplasm on the brain areas.

Diagnosis of arachnoid cyst of the parietal region is carried out using computed tomography or MRI methods.

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Convexital arachnoid cyst

A convexital arachnoid cyst forms on the surface of the cerebral hemispheres and is a hollow, rounded formation with liquid contents, the walls of which consist of cells of the arachnoid membrane.

If the cyst is small and there are no pronounced symptoms, treatment is not performed in most cases. However, if the amount of intracavitary fluid increases, the tumor can put pressure on the brain areas, thereby causing a number of characteristic symptoms, such as: headaches and dizziness, vomiting and nausea, hallucinations, noise or ringing in the ears, disorders of various body functions, etc.

In such cases, the tumor can be removed surgically or endoscopically, as well as by shunting.

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Arachnoid cyst of the sella turcica

The sella turcica is located in the projection of the sphenoid cranial bone and is a small depression that resembles a saddle in appearance.

An arachnoid cyst of the sella turcica is a tumor-like formation with a cavity consisting of arachnoid cells and liquid contents. This pathology can be diagnosed using computed tomography or MRI. Treatment is prescribed based on the size and progression of the neoplasm and can be carried out using endoscopic or surgical methods, as well as bypass.

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Arachnoid cyst of the lumbar spine

A lumbar arachnoid cyst forms in the lumen of the spinal canal and can put pressure on the nerve endings of the spinal cord, thereby causing the development of pain syndrome. In most cases, such formations are discovered accidentally during an examination of the lumbar spine.

Osteochondrosis and inflammatory processes in the lumbar spine, which result in the expansion of the spinal cord nerve roots and their filling with cerebrospinal fluid, can lead to the development of an arachnoid cyst in the lumbar region.

Trauma to this area can also provoke this type of tumor. In some cases, the occurrence of such formations does not have clearly defined causes.

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Arachnoid cyst of the sacral region

The arachnoid cyst of the sacral region is filled with cerebrospinal fluid, and its walls are lined with arachnoid cells.

This type of tumor may be a congenital formation. When the tumor is small, the symptoms are usually not expressed. When the tumor increases in size, it can put pressure on the nerve endings coming out of the spinal cord and cause moderate or severe pain.

In this case, pain can be felt both during motor activity and at rest, for example, while sitting. The pain can radiate to the buttocks, lumbar region, be felt in the abdomen and be accompanied by bowel and urination disorders. A crawling sensation and muscle weakness may occur in the lower extremities.

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Congenital arachnoid cyst

A congenital arachnoid cyst (true or primary) occurs during embryonic development and can be caused by trauma or any developmental abnormalities. Presumably, the occurrence of primary arachnoid cysts is associated with a disruption in the formation of the arachnoid membrane or subarachnoid space during embryogenesis. The exact causes of congenital arachnoid cysts have not been fully studied. A congenital arachnoid cyst can be combined with a more severe pathology of the central nervous system. Its detection can be accidental during the diagnosis of other diseases, since such cysts can exist asymptomatically. However, as the tumor progresses, the symptoms become quite pronounced, headaches, noise or ringing in the ears, convulsions occur, hearing and vision impairments may be noted, as well as other serious symptoms that require immediate medical intervention.

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Arachnoid cyst in children

An arachnoid cyst in children can be formed as a result of inflammatory processes that occurred during the intrauterine period. Also, the cause of such a neoplasm can be trauma during childbirth, developmental disorders of the fetus during the period of embryo formation, meningitis.

The tumor requires constant medical supervision. With rapid progression and pronounced symptoms of the disease, a decision may be made to remove the tumor. An ultrasound examination method allows diagnosing an arachnoid cyst.

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Arachnoid cyst in a newborn

An arachnoid cyst in a newborn may be the result of meningitis or other inflammatory processes, as well as brain injury. The causes of occurrence may also be associated with congenital pathology.

To diagnose arachnoid cysts in newborns, an ultrasound examination method is used. Since this type of tumor does not resolve on its own, constant medical supervision is required. The decision on the advisability of surgical intervention depends on factors such as tumor progression and the severity of the disease symptoms.

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What is the danger of an arachnoid cyst?

When an arachnoid cyst forms, the patient should be under the supervision of a doctor and monitor the progress of the disease. Undoubtedly, patients with such a diagnosis have a question: "What is dangerous about an arachnoid cyst?"

First of all, it should be noted that in the absence of timely treatment and rapid progression of the formation, fluid may continue to accumulate inside the tumor, putting pressure on areas of the brain. As a result, the symptoms of the disease intensify, various disorders of the visual, auditory organs, as well as memory and speech functions develop.

In case of rupture of an arachnoid cyst, as well as in severe forms of the disease, the absence of proper treatment can lead to the death of the patient.

Consequences

The consequences of an arachnoid cyst if the disease is not treated in a timely manner can lead to fluid accumulation inside the neoplasm and increased pressure on the brain areas. As a result, the symptoms of the disease increase, and various serious visual, auditory, speech and memory disorders may occur. If an arachnoid cyst ruptures, as well as at an advanced stage of the disease, the consequences may be irreversible, including death.

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Diagnostics

Arachnoid cysts are diagnosed using magnetic resonance imaging or computed tomography. In rare cases, when the posterior cranial fossa is affected or median suprasellar cysts are formed, an X-ray examination may be performed after the introduction of a contrast agent into the subarachnoid cisterns or ventricles of the brain.

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Treatment

Treatment of arachnoid cysts in the absence of symptoms and disease progression is usually not performed. The patient should be under the supervision of a physician in order to promptly identify an unfavorable course of the disease.

If the tumor size rapidly increases and severe symptoms of the disease appear, surgical treatment may be prescribed.

Methods used to remove the tumor include radical surgical interventions, which involve craniotomy and subsequent tumor removal. It should be noted that there is a risk of injury when using this method of treating arachnoid cysts.

The tumor can be removed by shunting, which involves draining the contents of the tumor using a drainage tube. There is a risk of infection when using this method.

Endoscopic removal is performed by puncturing the neoplasm and pumping out the intracavitary fluid. Trauma when using this method is minimal, but for some types of formations it is not used.

Arachnoid cyst removal

Removal of an arachnoid cyst can be performed using the following methods:

• Shunting is the process of ensuring the outflow of its contents into the slit-like space between the dura mater and arachnoid membrane of the brain.
• A fenestration method in which the tumor is excised by trepanning the skull.
• Drainage by pumping out the contents using a needle.

Prevention

Prevention of arachnoid cysts may consist of early diagnosis and timely treatment of inflammatory processes in the brain, various infections and traumatic brain injuries.

Forecast

The prognosis for an arachnoid cyst with timely detection of the neoplasm and qualified treatment is favorable. The main risks in the formation of this type of tumor are associated with an increase in its size and an increase in pressure on parts of the brain, as well as with the possibility of tumor rupture. The prognosis of the disease in such cases may include the development of quite serious complications that can lead to the disruption of various functions - memory, speech, hearing, vision. In an advanced form of the disease, an arachnoid cyst of the brain can lead to the development of hydrocephalus, brain hernia, or death.

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