Subependymal cyst in a newborn

When performing a brain neurosonography procedure, doctors sometimes detect a benign hollow neoplasm, after which they make the diagnosis “subependymal cyst in a newborn”. What is this pathology, how does it appear and is there a need for its treatment? How will such a cyst affect the growth and development of the child?

Let's say right away: this problem is not as terrible as it usually seems to parents. Next, you can read everything that you first need to know about the subependimal cyst in a newborn.

Epidemiology

They are found in up to 5.2% of all newborns using transfontanellar ultrasound in the first days of life. [1]

The subependymal cyst is a tiny neoplasm, often in the form of tears, inside which is concentrated cerebrospinal fluid - the liquid contents that wash the brain; located either in the caudotalamic groove, or along the anterior section of the caudate nucleus. The size of the cystic formation usually ranges from 2-11 millimeters. [2]

The most common cause of subependymal cyst formation is hypoxia or cerebral ischemia during labor. Although most experts are inclined to believe that the true causes of the pathology have not yet been disclosed.

Subependymal cysts are found in approximately five newborn children out of a hundred and, as a rule, have a favorable prognosis for the development and life of the child.

Causes of the subependymal cyst

With oxygen deficiency, which is observed in the fetus against the background of impaired placental circulation, the development of some serious pathologies and developmental failures of the baby is possible. One of these failures sometimes becomes subependymal cyst: this pathology is often diagnosed in newborns as a result of prolonged circulatory disorders, oxygen and / or nutrient deficiencies.

Subependymal cyst can be detected both during pregnancy and after the baby is born. In the process of gestation, such a cystic formation is not dangerous for the fetus, and under favorable circumstances it can disappear on its own even before the onset of labor.

The exact reasons for the formation of a subependymal cyst in newborns are unknown to doctors, [3] however,  it is believed that such factors can affect its development:

• hypoxic disorders associated with entanglement of the umbilical cord, or with placental insufficiency;
• defeat of a pregnant herpevirus;
• injuries to the baby during labor;
• severe or late toxicosis in the expectant mother;
• exposure to cocaine during pregnancy; [4], [5]
• rhesus incompatibility;
• iron deficiency anemia during pregnancy.

Risk factors

The risk group consists of babies born prematurely, as well as newborns with insufficient body weight. In addition, subependymal cysts are sometimes diagnosed with multiple pregnancies, due to a lack of oxygen in the brain tissue. As a result, some cells die, and in their place there is a neoplasm that, as it were, replaces the necrosis zone.

Important: the longer the period of oxygen deficiency, the larger the subependymal cyst will be.

Consider the basic factors of cyst formation in more detail:

• Ischemia processes are the most common root cause of cystic formation. In this case, ischemia is due to impaired blood flow in the brain tissues. A cavity is formed in the necrosis zone, which is subsequently filled with cerebrospinal fluid. If such a cyst is small, then we are not talking about any serious violations: treatment is usually not prescribed, but only monitoring of the problem area is established. In case of unfavorable dynamics (for example, with further enlargement of the cyst, with the appearance of neurological symptoms), KK treatment is started immediately.
• Hemorrhage is the next most common underlying cause of the appearance of a subependymal cyst. Hemorrhage often occurs against the background of infectious processes, acute oxygen deficiency, or with injuries during childbirth. In this case, injuries associated with intrauterine infections have the most unfavorable prognosis. [6]
• Hypoxic processes in tissues can be acute or moderate in nature and are usually associated with impaired placental circulation. Anemia, toxicosis in the later stages, multiple pregnancy, Rh incompatibility, polyhydramnios, fetoplacental insufficiency, infectious and inflammatory pathologies often become the trigger mechanism.
• Congenital rubella and cytomegalovirus infection (CMV) are the most common proven causes of subependimal cysts of non-hemorrhagic origin in newborns. [7]

Pathogenesis

Subependymal cyst is located in the area of impaired blood supply to the brain structures. Most often, this is a problem with ventricular localization. Unlike congenital cysts, subependymal cysts are usually located below the external corners of the lateral ventricles and behind the Monroe opening. [8] Subependimal cysts can be divided into two types: acquired (secondary to hemorrhage, hypoxia-ischemia or infection) and congenital (resulting from germinolysis). They are often present after hemorrhage in the germinal matrix of the 1st degree, which is associated with prematurity. [9]

In one out of ten children who, during intrauterine development or during the process of childbirth, have encountered herpesvirus, a “trace” remains on the nervous system. If the infection was generalized, a large percentage of children die, and the survivors often show neuropsychiatric disorders. The formation of subependymal voids caused by the virus is explained by subsequent damage to the germinal matrix - nerve fibers located near the lateral ventricles. Infection causes necrosis of nerve cells, the zones of which after some time are replaced by the formation of voids.

Hypoxic or ischemic damage, accompanied by softening and necrosis of the tissue, also ends with the replacement formation of cavities. Oxygen deficiency during fetal development or labor can negatively affect the nervous structures. The activity of free radicals, the production of acidic metabolic products, the formation of blood clots at the local level as a whole cause necrosis and the appearance of cysts near the ventricles. Such subependymal cysts can be multiple, up to 3 mm in diameter. During the subsidence of cavities, irreversible processes of atrophy occur with the appearance of neuroglial nodes.

With birth trauma and cerebral hemorrhages, cyst formation is caused by the resorption of leaked blood with the appearance of a void, which in the future will be taken as a subependimal cyst.

Symptoms of the subependymal cyst

The subependymal cyst in the ultrasound image has distinct boundaries, has a spherical or slit-like configuration. In some cases, multiple lesions are noted, while cysts are most often at different stages of development: some of them have just appeared, while others are already at the stage of “gluing” and disappearance.

The dimensions of the subependymal cyst in a newborn are usually 1-10 mm or more. They are formed symmetrically, on the left or right side, in the middle sections or horns of the lateral ventricles.

Subependymal cyst on the right in the newborn is no more common than on the left. The more pronounced the oxygen deficiency, the larger the tumor will have. If there was a hemorrhage, then subsequently the affected area will be in the form of a single cavity with a clear liquid content.

The subependymal cyst on the left of the newborn is usually not accompanied by a change in the size of the departments of the lateral ventricles, but in some cases they can still increase. Compression of adjacent tissues and further growth of the cavity are relatively rare.

Over the course of several months from the moment of the birth of the baby, the neoplasm gradually decreases, until its complete disappearance.

The clinical picture with a subependymal cyst is not always the same or completely absent. First of all, it depends on the size, size and location of the damage. With other combined pathologies, the symptoms are more severe and pronounced. Small cysts of a single location often do not reveal themselves in any way, do not affect the development of the child and do not cause complications.

The first signs of a dysfunctional subependymal cyst are as follows:

• sleep disturbances, excessive moodiness, crying for no reason;
• increased irritability, irritability, or apathy, lethargic and inhibited state;
• impaired motor development in children, increased muscle tone, and in severe cases - hypotension, hyporeflexia; [10]
• insufficient weight gain, weakened sucking reflex;
• deterioration in auditory and visual function;
• small trembling of the limbs, chin;
• profuse and rapid regurgitation;
• increased intracranial pressure (an outstanding and pulsating fontanel);
• cramps.

These symptoms are not always bright and clear. In the process of resorption of the subependymal cyst, the clinical picture usually weakens and even disappears. If the neoplasm continues to increase, then inhibition of psychomotor development, growth deficiency, and speech problems may be noted.

Subependymal cyst, which is accompanied by any suspicious symptoms, should be closely monitored by a doctor.

Complications and consequences

Subependymal cyst in newborns in the vast majority of cases disappears on their own within a few months, without the use of any therapeutic measures. However, it is necessary to observe the cyst, since in rare cases, but nevertheless, adverse dynamics, growth and growth of the neoplasm are possible. If this happened, then such complications may occur:

• coordination disorders, motor disorders;
• problems with the auditory and visual apparatus;
• hydrocephalus, accompanied by excessive accumulation of cerebrospinal fluid in the cerebral ventricles;
• encephalitis.

In children with subependymal cysts (SEC), there may be a temporary delay in physical growth after birth. [11]

Large subependymal cysts, which exert pressure on closely located brain structures, are most often removed with surgery.

Diagnostics of the subependymal cyst

Diagnosis is carried out using the ultrasound method in the first few days after the birth of the baby. Since the area of the large fontanel in the newborn is most often open, this makes it possible to consider all structural disorders without harming the baby. If the fontanel is closed, then magnetic resonance imaging becomes the optimal imaging method. Instrumental diagnostics is performed regularly, for several months, to observe the dynamics of the neoplasm.

If a woman has herpevirus or cytomegalovirus, then auxiliary tests are prescribed to clarify the diagnosis - this is an immunological diagnosis. This allows us to resolve the issue of subsequent therapeutic tactics. [12]

Immunological tests are complex and expensive, therefore, most often they are inaccessible to average families. In addition, even confirmed herpesvirus infection does not provide any information on the degree of brain damage in the newborn. For this reason, most experts believe that it is more logical to conduct an echoencephalography procedure: its results will indicate the severity and nature of the violation of the structure of the brain. The procedure is harmless and will not lead to unpleasant consequences for the baby.

Differential diagnosis

Differential diagnosis is carried out between the connective, subependimal cysts and periventricular leukomalacia. The last indicated pathology is localized above the angle of the lateral ventricles. The connective cyst is located at or slightly lower than the upper outer corner of the anterior horn and the lateral ventricle body, in front of the interventricular opening. The subependymal cyst is predominantly located below the level of the angle of the lateral ventricles and behind the interventricular opening.

Isolated SEC is usually a benign find. An accurate diagnosis is important for differentiating subependymal cysts from other pathological conditions of the brain using a combination of brain ultrasound and MRI. [13] Magnetic resonance imaging helps to confirm the information  [14] obtained by ultrasound, to consider the location of the subependymal cyst, to distinguish the neoplasm from the connective cyst and other periventricular brain lesions. [15]

Treatment of the subependymal cyst

The treatment regimen for subependymal cyst in newborns is determined depending on the severity of the lesion. With an asymptomatic cyst, treatment is not required: the problem is observed in dynamics, the child is periodically examined by a neurologist, ultrasound monitoring is performed (when the fontanel closes, MRI is performed). Sometimes the doctor prescribes nootropic and vitamin preparations, although the feasibility of such an appointment is doubtful by many experts.

In severe cases of damage, with combined brain pathologies, complex treatment is prescribed, using physiotherapy, massage and, of course, medications:

• Nootropic drugs improve metabolic processes in the tissues of the brain. These drugs include Piracetam, Nicergoline, Pantogam.
• Vitamin-mineral complexes improve tissue nutrition, stabilize tissue metabolism. A special role is played by B-group vitamins and magnesium-containing products.
• Diuretic drugs are appropriate for increasing risk of cerebral edema, or with increased intracranial pressure. The optimal diuretic drug is Diakarb.
• Anticonvulsants are used for seizure syndrome. Perhaps the appointment of Depakine, Carbamazepine.

In infectious processes, children receive immunotherapy with immunoglobulins (Pentaglobin, Cytotect), antiviral drugs (Virolex). The regimen is determined individually.

Surgery

Surgical removal of the subependymal cyst is extremely rare: only under the condition of unfavorable growth dynamics against the background of ineffective drug therapy. Surgical treatment can be performed using one of the following methods:

• The bypass method involves the removal of cerebrospinal fluid from the cystic cavity through a special tube, due to which the walls collapse and their fusion. The procedure is quite effective, but dangerous because of the risk of infection in the tissue.
• The endoscopic method is considered the safest, but it is not suitable for all patients - for example, it can not be used for visual impairment in the patient.
• Craniotomy is considered an effective operation and is used for significant cystic masses.

A pediatric neurosurgeon performs such interventions only with obvious progression and an increase in subependymal cyst, with a high risk of complications. During the operation, computer monitoring is performed: the image is displayed on the monitor, so the doctor has the ability to track all the important operational points, analyze and correct the manipulation.

Prevention

Preventive measures to prevent the formation of subependimal cysts in children are based on such criteria:

• mandatory pregnancy planning;
• early prenatal diagnostic measures;
• prevention of injury during labor;
• neurological and pediatric monitoring of children belonging to risk groups.

In addition, it is important to exclude any teratogenic effects, especially in the early stages of the gestational period.

If necessary, the doctor may recommend that a pregnant woman undergo a genetic consultation.

Forecast

If the subependymal cyst is isolated - that is, it is not accompanied by neurological symptoms, has no connection with other pathologies, has typical characteristics and is detected by ultrasound by chance, then we can talk about a good prognosis. Such neoplasms disappear on their own within a few months. The prognosis of isolated subependymal cysts remains uncertain. [16]

Poor prognosis is indicated if a subependymal cyst in a newborn is combined with other developmental abnormalities.