Arakhnoidalny cyst of a brain
Arakhnoidalny cyst of a brain — the education filled with tserebrospinalny liquid which is settling down between duplikatury an arakhnoidalny cover. Can have the congenital and secondary nature. Often proceeds latentno, without clinical manifestations. At increase in volume the cyst debuts symptoms of intra cranial hypertensia, convulsive paroxysms and focal neurologic deficiency. It is diagnosed generally according to brain MRT. At increase of clinical symptoms surgical treatment — drainage of a cyst, its fenestration, excision or shunting is required.
Arakhnoidalny cyst of a brain
The Arakhnoidalny cyst of a brain represents a limited congestion of tserebrospinalny liquid (likvor) in the thickness of the covers covering a brain. The cyst received the name in connection with localization in an arakhnoidalny cerebral cover. In the place of formation of a cyst the arakhnoidalny cover is thickened and has a duplikatura, i.e. is divided into two leaves between which tserebrospinalny liquid collects. As a rule, cysts have small volume, but at a congestion in them a large number of a likvor, they make compression impact on the subject cerebral cortex. It leads to a demonstration of clinical manifestations of intrakranialny (intra cranial) volume education.
The Arakhnoidalny cyst of a brain can have various location. Most often such cysts are in area of a mostomozzhechkovy corner, silviyevy furrow and over the Turkish saddle (suprasellyarno). According to the available data about 4% of the population have arakhnoidalny cysts, but not at all they give any clinical manifestations. Are more subject to developing of cysts of the male.
Classification of arakhnoidalny cysts
Etiologichesky classification considers an origin of arakhnoidalny cerebral cysts. On the origin they can be primary, or congenital, and secondary, or acquired. Primary cysts belong to anomalies of development of a brain, secondary arise as a result of the traumatic damages, inflammatory processes or bleedings occurring in cerebral covers.
Morphologically allocate simple and difficult arakhnoidalny cysts. In the first case the cavity of a cyst is sent by the cages of an arakhnoidalny cover having ability to produce tserebrospinalny liquid. In the second case the structure of a cyst includes also other fabrics, for example, glial elements. Morphological classification of arakhnoidalny cysts has no relevance to practical neurology while etiologichesky classification is surely considered at statement of the developed diagnosis.
Clinically arakhnoidalny cysts subdivide on progressing and stood. The progressing cysts differ in the increase of neurologic symptomatology caused by increase in volume of a cyst. The stood cysts do not increase in sizes and usually have a latent current. Definition of a type of an arakhnoidalny cyst according to this classification has paramount value for the choice of adequate tactics of treatment.
Causes of an arakhnoidalny cyst
Congenital arakhnoidalny cysts are formed owing to violations in the course of pre-natal development of a brain. Various harmful impacts on a fruit happening during pregnancy belong to the factors causing their education. It can be pre-natal infections (toxoplasmosis, a rubella, herpes, a cytomegalic inclusion disease, etc.), intoxications (professional harm, alcoholism, smoking, drug addiction, reception of pharmaceuticals with teratogenny effect), radiation exposure, overheating (visit by the pregnant woman of a sauna or bath, excess insolation, a habit to take hot baths). The cysts which are localized in an arakhnoidalny cover are often noted at patients with Marfan's syndrome and a gipogeneziya of a calloused body.
The acquired arakhnoidalny cysts arise after craniocereberal injuries (concussion of a brain, a brain bruise), and also can be a consequence of operations on a brain. Formation of a secondary cyst perhaps after the postponed meningitis, an arakhnoidit or an encephalomeningitis. Formation of an arakhnoidalny cyst can be observed after permission of subarakhnoidalny hemorrhage or a subduralny hematoma. The factors capable to provoke formation of an arakhnoidalny cyst can cause also progressing growth of volume of the small subclinical cystous education which is earlier existing in an arakhnoidalny cover due to hyperproduction and a congestion in it tserebrospinalny liquid.
Symptoms of an arakhnoidalny cyst
In most cases the arakhnoidalny cyst of a brain has insignificant volume and does not prove clinically in any way. The congenital cyst can be a casual find when performing a neyrosonografiya through a fontanel or MRT of a brain in connection with other intrakranialny pathology. Her clinical debut at infectious, vascular or traumatic damage of a brain is possible.
At increase in quantity of the likvor which is in a cyst and respectively sizes of the cyst appear symptoms of the increased intra cranial pressure and focal neurologic manifestations which nature depends on the location of a cyst. The patient is disturbed by headaches (tsefalgiya), periodic dizziness, noise in ears, feeling of "the heavy head", sometimes — feeling of "pulsation" in the head, instability of walking.
To increase of volume of a cyst there is an aggravation of the specified symptomatology. Tsefalgiya gains constant and intensive character, is followed by nausea, pressure upon eyeballs, vomiting. Relative deafness development (hearing falling), decrease in visual acuity, doubling or emergence of "spots" in fields of vision, a sleep of these or those extremities, a vestibular ataxy, a dizartriya are possible. A hemiparesis — decrease in muscular force in a hand and a leg of one half of a body can be noted. Episodes of emergence of convulsive attacks and sinkopalny states (faints) are frequent. The hallucinatory syndrome is in some cases observed. Children have a delay of mental development.
Aggravation of neurologic symptomatology demonstrates further growth of the sizes of an arakhnoidalny cyst and the progressing brain sdavleniye. Significant increase in volume of a cyst is dangerous by a possibility of its gap involving the death of the patient. Long existence of a cerebral compression leads to irreversible degenerate processes in brain fabrics with formation of resistant neurologic deficiency.
Diagnosis of an arakhnoidalny cyst
The clinic of an arakhnoidalny cyst has no specific manifestations and corresponds to a clinical picture, the general for the majority of volume formations of a brain. Intracerebral and obolochechny hematomas, primary and metastatic tumors of a brain, brain abscess, an intracerebral cyst concern to the last. Survey of the neurologist and primary neurologic inspection (an electroencephalography, a rheoencephalography and an echo encephalography) allow to establish existence of intrakranialny education with intra cranial hypertensia and the existing convulsive activity of a brain. Specification of nature of volume education and its localization requires carrying out MPT, CKT of a brain or KT.
As optimum diagnostic method for recognition of arakhnoidalny cysts brain MRT with contrasting acts. Use of contrast substances allows to otdifferentsirovat a cyst from a brain tumor. The main criterion of an arakhnoidalny cyst distinguishing it from a tumor is lack of ability to accumulate contrast. By means of MRT differential diagnostics with a subduralny hematoma, subarakhnoidalny hemorrhage, subduralny gigromy, abscess, a stroke, encephalitis, etc. cerebral diseases is carried out.
Treatment of an arakhnoidalny cyst
The stood arakhnoidalny cysts with a subclinical current do not need therapy. Observation of the neurologist and annual passing of MRT for dynamic control of the sizes of a cyst is recommended to patients. The progressing arakhnoidalny cysts, cysts which are followed by epilepsy and/or the substantial increase of intra cranial pressure which is not stopped by conservative methods of therapy are subject to surgical treatment. For the solution of a question of expediency of surgical treatment of an arakhnoidalny cyst and the choice of an optimum way of its implementation consultation of the neurosurgeon is held.
In the presence of hemorrhage to the area of an arakhnoidalny cyst and at its gap full excision of a cyst is shown. However such method of treatment is highly traumatic and demands the long recovery period. Therefore in the absence of complications preference is given to endoscopic intervention from a so-called fenestratsiy cyst. Operation is performed through a frezevy opening and consists in aspiration of contents of a cyst with the subsequent creation of the openings connecting a cyst cavity to a ventricle of a brain and/or subarakhnoidalny space. In certain cases apply the shunting operation - kistoperitonealny shunting as a result of which tserebrospinalny liquid from a cavity of a cyst flows in an abdominal cavity where it is soaked up. A lack of similar operations is the probability of violation of passability of the shunt.
Forecast and prevention
The Arakhnoidalny cyst of a brain can have the most various current. In many cases it asymptomatically exists throughout all life of the patient. Danger is constituted by the progressing arakhnoidalny cysts. At overdue diagnostics they can serve as the reason of invalidiziruyushchy neurologic deficiency and even a lethal outcome. Timely performing surgical treatment of a cyst, as a rule, leads to recovery. The cyst recurrence can be a complication.
Prevention of congenital arakhnoidalny cysts, as well as the prevention of other defects of pre-natal development, includes correct conducting pregnancy and observance of the pregnant woman of the special guarding mode excluding harmful effects on a fruit. The correct and timely treatment of injuries, inflammatory and vascular cerebral diseases acts as prevention of the acquired arakhnoidalny cysts.