Cerebral cyst is a voluminous intracranial formation, which is a cavity filled with fluid. It often has a latent subclinical course without an increase in size. It is manifested mainly by symptoms of intracranial hypertension and epileptic paroxysms. Focal symptoms are possible, corresponding to the location of the cyst. It is diagnosed according to the results of MRI and CT of the brain, in infants — according to neurosonography. Treatment is carried out with progressive cyst growth and the development of complications, consists in surgical removal or aspiration of the cyst.
ICD 10
G93.0 Cerebral cysts
General information
Cerebral cyst is a local accumulation of fluid in the membranes or substance of the brain. A small-volume cyst, as a rule, has a subclinical course, is detected accidentally during a neuroimaging examination of the brain. A large cyst due to the limited intracranial (intracranial) space leads to intracranial hypertension and compression of the surrounding brain structures. The clinically significant size of cysts varies significantly depending on their localization and compensatory capabilities. Thus, in young children, due to the malleability of the skull bones, there is often a long latent course of cysts without signs of pronounced cerebrospinal hypertension.
Cerebral cyst can be detected at various age periods: from newborn to old age. It should be noted that congenital cysts are more common in middle age (usually 30-50 years) than in childhood. According to the practice generally accepted in clinical neurology, an observational and expectant management tactic is applied to frozen or slowly progressing cysts of small volume.
Classification
Depending on the location, an arachnoid and intracerebral (cerebral) cyst are isolated. The first is localized in the meninges and is formed due to the accumulation of cerebrospinal fluid in the places of their congenital duplication or adhesions formed as a result of various inflammatory processes. The second one is located in the internal structures of the brain and is formed on the site of brain tissue that died as a result of various pathological processes. Pineal gland cyst, vascular plexus cyst, colloidal and dermoid cysts are also isolated separately.
All cerebral cysts are classified according to their genesis into congenital and acquired. Exclusively congenital include dermoid and colloidal cyst of the brain. According to the etiology, post-traumatic, post-infectious, echinococcal, post-stroke cysts are distinguished among acquired cysts.
Causes
The factors provoking the formation of a congenital cerebral cyst are any adverse effects on the fetus in the antenatal period. These include fetoplacental insufficiency, intrauterine infections, taking pregnant drugs with a teratogenic effect, Rh conflict, fetal hypoxia. Congenital cysts and other brain development abnormalities may occur if the fetus develops under conditions of intrauterine intoxication with drug addiction, alcoholism, nicotine dependence of the expectant mother, as well as if she has chronic decompensated diseases.
Acquired cyst is formed as a result of traumatic brain injury, birth trauma of a newborn, inflammatory diseases (meningitis, arachnoiditis, brain abscess, encephalitis), acute disorders of cerebral circulation (ischemic and hemorrhagic stroke, subarachnoid hemorrhage). It may have a parasitic etiology, for example, with echinococcosis, cerebral form of teniosis, paragonimosis, a cyst of iatrogenic origin may form as a complication of brain surgery. In some cases, various dystrophic and degenerative processes in the brain are also accompanied by the replacement of cerebral tissues with a cyst.
A separate group consists of factors that can provoke an increase in the size of an already existing intracranial cystic formation. Similar triggers can be head injuries, neuroinfections, inflammatory intracranial processes, vascular disorders (strokes, difficulty in venous outflow from the cranial cavity), hydrocephalus.
Symptoms
The most characteristic manifestation of a cerebral cyst with symptoms of intracranial hypertension. Patients complain of almost constant cephalgia, a feeling of nausea not related to food, a feeling of pressure on the eyeballs, decreased performance. There may be sleep disturbances, noise or a feeling of pulsation in the head, visual disturbances (drop in visual acuity, double vision, narrowing of visual fields, the appearance of photopsias or visual hallucinations), mild hearing loss, ataxia (dizziness, shakiness, discoordination of movements), fine-pitched tremor, fainting. With high intracranial hypertension, repeated vomiting is observed.
In some cases, the cyst of the brain debuts for the first time with an epileptic paroxysm, followed by repeated epiprimes. Paroxysms can be of a primary generalized nature, have the form of absences or focal Jackson epilepsy. Focal symptoms are observed much less frequently than cerebral manifestations. In accordance with the localization of cystic formation, it includes hemi- and monoparesis, sensory disorders, cerebellar ataxia, stem symptoms (oculomotor disorders, swallowing disorders, dysarthria, etc.).
Complications
A complication of the cyst may be its rupture, occlusive hydrocephalus, compression of the brain, rupture of a vessel with hemorrhage into the cyst, the formation of a persistent epileptogenic focus. In children, cysts accompanied by severe intracranial hypertension or episindrome may cause a delay in mental development with the formation of oligophrenia.
Certain types of cerebral cyst
Arachnoid cyst is more often congenital or post-traumatic. Located in the meninges on the surface of the brain. Filled with cerebrospinal fluid. According to some data, up to 4% of the population have arachnoid cysts of the brain. However, clinical manifestations are observed only in the case of a large accumulation of fluid in the cyst, which may be due to the production of liquor lining the cyst cavity cells. A sharp increase in the size of the cyst threatens to rupture it, leading to a fatal outcome.
Pineal cyst (pineal cyst) is a cystic formation of the epiphysis. Some data indicate that up to 10% of people have small asymptomatic pineal cysts. Cysts with a diameter of more than 1 cm are noted much less often and can give clinical symptoms. When reaching a significant size, the pineal gland cyst is able to block the entrance to the brain’s water supply and block the cerebrospinal fluid circulation, causing occlusive hydrocephalus.
Colloidal cyst accounts for about 15-20% of intraventricular formations. In most cases, it is located in the anterior region of the III ventricle, above the Monroe hole; in some cases, in the IV ventricle and in the area of the transparent septum. The filling of the colloidal cyst is characterized by high viscosity. The basis of clinical manifestations are the symptoms of hydrocephalus with a paroxysmal increase in cephalgia at certain head positions. Behavioral disorders, memory loss are possible. Cases of weakness in the extremities are described.
A cyst of the vascular plexus is formed when the cerebrospinal fluid fills the space between the individual vessels of the plexus. It is diagnosed at different ages. Clinically manifested rarely, in some cases it may give symptoms of intracranial hypertension or epilepsy. Often, vascular plexus cysts are detected according to obstetric ultrasound at the 20th week of pregnancy, then they resolve independently and by about the 28th week of intrauterine development are no longer detected on ultrasound.
Dermoid cyst (epidermoid) is an anomaly of embryonic development, in which the cells that give rise to the skin and its appendages (hair, nails) remain inside the brain. The contents of the cyst, along with the fluid, are represented by elements of the ectoderm (hair follicles, sebaceous glands, etc.). It differs in the rapid increase in size that occurs after birth, and therefore must be removed.
Diagnostics
Clinical symptoms and neurological status data allow the neurologist to suspect the presence of intracranial volume formation. To check hearing and vision, the patient is referred to an otolaryngologist and an ophthalmologist; audiometry, visiometry, perimetry and ophthalmoscopy are performed, where stagnant optic nerve discs are noted with severe hydrocephalus. Increased intracranial pressure can be diagnosed using echoencephalography. The presence of epileptic paroxysms is an indication for electroencephalography. However, relying only on clinical data, it is impossible to verify a cyst from a hematoma, abscess or brain tumor. Therefore, if a volumetric brain formation is suspected, it is necessary to use neuroimaging diagnostic methods.
The use of ultrasound makes it possible to identify some congenital cysts even during intrauterine development, after the birth of a child and before the closure of his large fontanel, diagnosis is possible with the help of neurosonography. In the future, the cyst can be visualized by CT or MRI of the brain. To differentiate a cystic formation from a brain tumor, these studies are carried out with contrast, because unlike a tumor, a cyst does not accumulate a contrast agent. For better visualization of the cystic cavity, it is possible to introduce contrast into it by puncture of the cyst. Unlike MRI, CT of the brain makes it possible to judge the viscosity of the cyst contents by the density of its image, which is taken into account when planning surgical treatment. It is of fundamental importance not only to establish a diagnosis, but also to continuously monitor cystic formation to assess changes in its volume over time. In case of post-stroke genesis of cysts, vascular examinations are additionally resorted to: duplex scanning, ultrasound, CT or MRI of cerebral vessels.
Treatment
Conservative therapy is ineffective. Treatment is possible only surgically. However, most cysts do not need active treatment because they are small and do not progress in size. In relation to them, regular dynamic monitoring is carried out using MRI or CT control. Neurosurgical treatment is subject to cysts clinically manifested by symptoms of hydrocephalus, progressively increasing in size, complicated by rupture, bleeding, compression of the brain. The choice of the method of operation and surgical approach is carried out at the consultation of a neurosurgeon.
In cases of severe condition of a patient with a disorder of consciousness (sopor, coma), external ventricular drainage is urgently indicated to reduce intracranial pressure and compression of the brain. In case of complications in the form of cyst rupture or hemorrhage, as well as in case of parasitic etiology of the cyst, surgical intervention is performed with the aim of radical excision of the cystic formation; surgical access is skull trepanation.
In other cases, the operation is planned and is carried out mainly by endoscopic method. The advantage of the latter is a low injury rate and a shortened recovery period. For its implementation, only a milling hole in the skull is needed, through which the cyst contents are aspirated. In order to prevent the repeated accumulation of fluid in the cystic cavity, a number of holes are made connecting it to the cerebrospinal fluid spaces, or cystoperitoneal bypass surgery is performed. The latter involves the implantation of a special shunt, through which fluid from the cyst enters the abdominal cavity.
In the postoperative period, complex rehabilitation therapy is carried out, in which, if necessary, a neuropsychologist, a physical therapy doctor, a masseur, a reflexologist take part. The medicinal component includes absorbants, drugs that improve blood supply and metabolism of the brain, decongestant and symptomatic medications. In parallel, in order to restore muscle strength and sensitive function, to adapt the patient to physical exertion, physiotherapy, physical therapy, massage, reflexotherapy are carried out.
Forecast
A clinically insignificant frozen cyst of the brain in most cases retains its non-progressive status and does not bother the patient in any way during his life. Timely and adequately performed surgical treatment of clinically significant cysts causes their relatively favorable outcome. A residual moderately pronounced cerebrospinal hypertension syndrome is possible. In the case of the formation of a focal neurological deficit, it may have a persistent residual character and persist after treatment. Epileptic paroxysms often pass after removal of the cyst, but then they often resume, due to the formation of adhesions and other changes in the operated area of the brain. At the same time, secondary epilepsy is characterized by resistance to anticonvulsant therapy.
Prevention
Since an acquired cerebral cyst is often one of the options for resolving infectious, vascular, inflammatory and post-traumatic intracranial processes, its prevention is timely and correct treatment of these diseases with the use of neuroprotective and resorption therapy. With regard to congenital cysts, prevention is the protection of the pregnant woman and the fetus from the influence of various harmful factors, the correct management of pregnancy and childbirth.
