VENTRICLES OF THE BRAIN (ventriculi cerebri) — the cavities which are in a brain, covered by an ependyma and filled with cerebrospinal liquid. Functional value Zh. of m is defined by the fact that they are the place of education and a receptacle cerebrospinal liquid (see), and also part of likvoroprovodyashchy ways.
Is available four ventricles: side ventricles (ventriculi lat., the first and second), third ventricle (ventriculus tertius) and fourth ventricle (ventriculus quartus). Are for the first time described by Gerofil in 4 century BC. In studying of likvoroprovodyashchy ways opening of a brain water supply system by F. Sylvius, an interventricular foramen of A. Monro, a median opening of the fourth ventricle of F. Marangdi, side openings of the fourth ventricle by G. Lushka, and also introduction to medical practice of a method of a ventrikulografiya were important At. Dandy (1918).
Progress of cerebrospinal liquid is directed to IZ Zh. of m through an unpaired median opening of the fourth ventricle (Marangdi) and pair side openings of the fourth ventricle (Lushki) in the cerebellar and brain tank, from there cerebrospinal liquid extends on tanks of the basis of a brain, beds along crinkles of a brain to its convex surface and in subarachnoid space of a spinal cord and its central channel. Capacity of all ventricles makes 30 — 50 ml.
. of m as well as cavities of a spinal cord [the central channel (canalis centralis) and a final ventricle (ventriculus terminalis)], form as a result of transformations of primary cavity of a neurotubule — the nervous channel. The nervous channel throughout a spinal cord gradually is narrowed and turns into the central canal and into a final ventricle. The front end of a neurotubule extends and then is dismembered, forming three brain bubbles (fig. 1) on the 4th week of development: front, average and rhomboid. On 5 — 6th week of development by a differentiation of three brain bubbles five bubbles, to originative five main departments of a brain form: to an end brain (telencephalon), diencephalon (diencephalon), mesencephalon (mesencephalon), metencephal (metencephalon), myelencephalon (myelencephalon).
The end brain strenuously grows in the parties, forming two side bubbles — rudiments of hemicerebrums. Primary cavity of an end brain (telocele) gives rise to cavities of side bubbles which represent laying of side ventricles. On 6 — 7th week of development growth of side bubbles happens in the lateral and front directions that leads to formation of a front horn of side ventricles; on 8 — growth of side bubbles in an opposite direction is observed 10th week owing to what back and lower horns of ventricles appear. Thanks to the strengthened growth of temporal shares of a brain the lower horns of ventricles move lateralno, down and forward. The part of a cavity of an end brain which is in connection with cavities of side bubbles turns into interventricular foramens (foramina interventricularia) which report side ventricles with the forefront of the third ventricle. Primary cavity of a diencephalon (diocele) is narrowed, keeping communication with a median part of a cavity of an end brain, and gives rise to the third ventricle. The cavity of a mesencephalon (mesocele) passing in front into the third ventricle is very strongly narrowed and on the 7th week turns into the narrow canal — the water supply system of a brain (aqueductus cerebri) connecting the third ventricle with the fourth. In the same time a cavity of a rhombencephalon which gives rise back and to a myelencephalon, extending lateralno, forms the fourth ventricle with its side pockets (recessus lat.). The vascular basis of the fourth ventricle (tela chorioidea ventriculi quarti) almost completely closes in the beginning his cavity (except for an opening of a water supply system of a brain). To the 10th week of development in it and in a wall of a ventricle openings form: one median (apertura mediana) at a bottom corner of a rhomboid pole and two steam rooms side (aperturae lat.) at tops of lateral pockets. By means of the listed openings the fourth ventricle is reported with subarachnoid space of a brain. The cavity of the fourth ventricle passes below into the central canal of a spinal cord.
Side ventricles are in hemicerebrums (fig. 2 — 4 and tsvetn. fig. 11). They consist of the central part (pars centralis), edges lies in a parietal lobe, and three shoots departing from it from each party — horns. Front horn (cornu ant.) there is in a frontal lobe, a back horn (cornu post.) — in an occipital share, the lower horn (cornu inf.) — in a temporal share. The front horn has triangular shape, is limited by a transparent partition (septum pellucidum), outside and behind from within — a head of a kernel (caput nuclei caudati) having a tail, from above and in front — a corpus collosum (corpus callosum). Between two plates of a transparent partition there is her cavity (cavum septi pellucidi). The central part of a ventricle has the form of a crack, a bottom a cut is formed by a kernel having a tail, outside department of an upper surface of a thalamus and the final strip (stria terminalis) lying between them. Knutri it is closed by an epithelial plate [lamina chorioidea epithelialis (BNA)], from above is covered with a corpus collosum. The back horn and down — the lower horn departs from the central part of a side ventricle of a kzada. The place of transition of the central part to back and lower horns carries the name of a collateral triangle (trigonum collaterale). The back horn lying among white matter of an occipital share of a brain has triangular shape, gradually it is narrowed kzad; on its inner surface — two longitudinal ledges: lower — a bird's spur (calcar avis) corresponding to a shporny furrow, and upper — a bulb of a back horn (bulbus cornus post.), formed by fibers of a corpus collosum. The lower horn goes down and forward and comes to an end at distance of 10 — 14 mm from a temporal pole of hemispheres. Its upper wall is formed by a tail of a kernel having a tail and a final strip. On a medial wall there passes the eminence — a hippocampus (hippocampus), a cut is created owing to impression lying deeply from a surface of a hemisphere of a parahippocampal furrow (gyrus parahippocampalis). The lower wall, or bottom of a horn, is limited to white matter of a temporal share and bears on itself the roller — a collateral eminence (eminentia collateralis) corresponding outside to a collateral furrow. From the medial party in the lower horn the soft meninx forming a vascular texture of a side ventricle vpyachivatsya (plexus chorioideus ventriculi lat.). Side ventricles are closed from all directions, except for an interventricular (monroyev) opening [foramen interventriculare, PNA; foramen interventriculare (Monroi), BNA], through a cut side ventricles connect to the third ventricle and by means of it — with each other.
The third ventricle — the unpaired cavity having the shcheleobrazny form. It is located in a diencephalon in the middle between the medial surfaces of thalamuses and a hypothalamus. In front of the third ventricle are front commissure (commissura ant.), column of the arch (columna fornicis), final plate (lamina terminalis); behind — back commissure (commissura post.), commissure of leads (commissura habenularum); from below — the back made a hole substance (substantia perforata post.), gray hillock (tuber cinereum), mastoidal bodies (corpora mamillaria) and visual decussation (chiasma opticum); from above — the vascular basis of the third ventricle which is attached to an upper surface of a thalamus, and over it — the legs of the arch (crura fornicis) tied by a commissure of the fornix and a corpus collosum. Lateralno from the centerline the vascular basis of the third ventricle contains a vascular texture of the third ventricle (plexus chorioideus ventriculi tertii). B to the middle of the third ventricle the right and left thalamus are connected by an interthalamic union (adhesio interthalamica). The third ventricle forms deepenings: deepening of a funnel (recessus infundibuli), visual deepening (recessus opticus), epiphyseal deepening (recessus pinealis). By means of a water supply system of a brain [aqueductus cerebri, PNA; aqueductus cerebri (Sylvii), BNA] the third ventricle connects with the fourth.
Fourth ventricle. The bottom of the fourth ventricle, or a rhomboid pole (fossa rhomboidea), is formed bridge of a brain (see) and myelencephalon (see) on which border the fourth ventricle forms lateral deepenings (recessus lat. ventriculi quarti). The roof of the fourth ventricle (tegmen ventriculi quarti) has the form of a tent and is made by two brain sails — unpaired upper (velum medullare sup.), stretched between upper legs of a cerebellum, and to steam rooms lower (velum medullare inf.), fixed to legs of a scrap (pedunculus flocculi). Between sails the roof of a ventricle is formed by a cerebellum. The lower brain sail is covered with a vascular basis of the fourth ventricle (tela chorioidea ventriculi quarti), about a cut the vascular texture of a ventricle is connected. The cavity of the fourth ventricle is reported with subarachnoidal space three openings: unpaired median [apertura mediana ventriculi quarti, PNA; apertura medialis ventriculi quarti (foramen Magendi), BNA], the being no of the centerline in lower parts of the fourth ventricle, and pair side [aperturae lat. ventriculi quarti, PNA, BNA (foramina Luschkae)] — in the field of lateral deepenings of the fourth ventricle. In lower parts the fourth ventricle, being gradually narrowed, passes into the central canal of a spinal cord which below extends in a final ventricle.
Pathology can be caused by development in. of m of inflammatory processes, hemorrhages, localization of parasites, tumors.
Inflammatory processes in. m (ventrikulit) can be observed at various infectious defeats and intoxications of c. N of page (e.g., at meningoentsefalita, etc.). At an acute ventrikulit the picture of a serous or purulent ependimatit can develop (see. Horioependimatit ). At hron, productive periventrikulyarny encephalitis there is a consolidation of the ependyma of ventricles sometimes taking a granular form that is caused by warty reactive growths of a subependimarny layer. The current of an ependimatit is quite often made heavier owing to disturbances of circulation of cerebrospinal liquid because of obturation of ways of its outflow at the level of interventricular foramens, a water supply system of a brain, an unpaired median opening of the fourth ventricle.
Clinically disturbances of circulation of cerebrospinal liquid at ventrikulita are shown by paroxysms of headaches during which patients depending on the level of difficulty of outflow of cerebrospinal liquid adopt characteristic forced provisions with a ducking forward, its zaprokidyvaniye, etc. back (see. Occlusal syndrome ). Nevrol, symptomatology at ventrikulita of a polimorfn; it is shown by a wide range of symptoms from periventrikulyarny (okolozheludochkovy) structures of diencephalic departments of a brain (arterial hypertension, a hyperthermia, not sugar mocheiznureniye, a narcolepsy, a cataplexy), a mesencephalon (oculomotor disturbances), back and a myelencephalon — a bottom of the fourth ventricle (vestibular disturbances, symptoms of defeat of kernels VI, VII cranial nerves, etc.). At acute ventrikulita in ventricular cerebrospinal liquid the cytosis is usually noted, at chronic — ventricular liquid can be gidrotsefalny (decrease in protein content at normal quantity of cells).
Primary hemorrhages in. of m meet seldom and in most cases happen traumatic genesis. The secondary hemorrhages which are result of break of intracerebral hematomas (traumatic, after a stroke) in a cavity of ventricles are more often observed. These hemorrhages are shown by acute development of coma with sharply expressed reactions from cardiovascular system, the disturbances of breath, a hyperthermia dissociated by meningeal symptoms, often gormetonichesky syndrome (see. Gormetoniya ). In cerebrospinal liquid find impurity of blood.
From parasitic defeats. of m cysticercosis, Echinococcosis and a coenurosis most often meet. As the basic a wedge, as their manifestation serve symptoms of an aseptic ependimatit with disturbances of circulation of cerebrospinal liquid. The last can be also caused by obturation of ways of a likvoroottok the parasite who is freely swimming in ventricular liquid. Also the headaches developing at a certain position of the head, forced position of the head, a gipertenzionno-gidrotsefalny syndrome are noted. In the analysis of cerebrospinal liquid — a picture of aseptic meningitis. At localization of parasites in the fourth ventricle Bruns's syndrome can develop (see. Occlusal syndrome ).
Tumors. of m are subdivided on primary which develop from vascular textures, an ependyma or a subependimny glia, and secondary — burgeoning in ventricles from the next formations of a brain. Among primary tumors ependymomas (fig. 5), horioidpapillom (fig. 6), meningiomas meet more often, astrocytomas (fig. 7) and spongioblastomas are more rare (see. Brain, tumors ). Tumors of side ventricles are clinically shown by a remittiruyushchy current with an occlusal gidrotsefalnymi paroxysms owing to obturation of interventricular foramens. During paroxysms forced position of the head and symptoms of infringement of trunk departments of a brain is noted (paralysis of a look up, bilateral patol. reflexes standing, disturbances of cardiovascular activity and breath). The dissociated Meningeal symptoms as manifestation of tonic reflexes owing to irritation of trunk structures of a brain are often observed. Besides, periventrikulyarny symptoms as result of impact of a tumor on the adjacent departments of a brain (changing in time on degree of manifestation motive and sensitive disturbances, a hemianopsia, unilateral symptoms of subcrustal defeat, the general epileptic seizures with a tonic convulsive component, etc.) can come to light. In ventricular cerebrospinal liquid the sharp increase in protein which is quite often combined with increase in quantity of cells and a xanthochromia is usually noted.
The combination of gipertenzionno-gidrotsefalny symptoms owing to occlusion of ways of circulation of cerebrospinal liquid — a water supply system of a brain and interventricular (monroyevy) foramens with various exchange and endocrine and vegetovascular disturbances which often serve as the first displays of a disease is characteristic of tumors of the third ventricle. Attacks of kataplektoidny type, disturbance of a rhythm of a dream, sometimes patol, drowsiness are observed. In late stages of a disease — attacks of a cerebrate rigidity with disturbances of breath and cardiovascular activity. In cerebrospinal liquid usually substantial increase of protein, sometimes with increase in quantity of cells and a xanthochromia.
Wedge, picture of a tumor of the fourth ventricle consists of symptoms of defeat of nuclear formations of periventrikulyarny structures of its bottom and gipertenzionno-gidrotsefalny symptoms owing to obturation of outflow tracts of cerebrospinal liquid. Paroxysms of headaches with vomiting, dizziness and disturbance of cardiovascular activity and breath (Bruns's attacks) are characteristic. A constant symptom — the expressed stem nystagmus.
At diagnosis of pathology. of m, in addition to the analysis of features a wedge, manifestations, apply ventrikulografiya (see), ventrikuloskopiya (see) and encephalography (see) with use of water-soluble emulsion and gas radiopaque substances and radioisotopes (fig. 8 — 10).
Treatment at tumors, hematomas and parasites. of m only surgical. Make a ventrikulotomiya for removal of the intra ventricular center (see) — a section of a wall of a ventricle with opening of its gleam.
At inflammatory processes resort to an operative measure in cases of development of the occlusal phenomena (see. Hydrocephaly ). As the temporary measure at acute occlusions of ways of a likvoroottok for decrease in chamber pressure is used ventriculopuncture (see).
In cases when occlusion cannot be surgically eliminated, make the palliative operations directed to creation of a sideway of outflow of cerebrospinal liquid from ventricles (operation of a ventriculostomy, perforation of a final plate, a ventrikulosubduralny anastomosis, a ventrikulotsisternostomiya).
From conservative methods of treatment of ventrikulit to cerebral decompression and reduction of a hypertensive syndrome apply dehydration (see. Dehydrational therapy ). At the acute and chronically proceeding infectious ventrikulita carry out antiinflammatory treatment.
The forecast at tumors. of m is always serious and is defined by their high quality, localization within ventricular system and the relation to adjacent formations of a brain. At hemorrhages in. of m in most cases forecast adverse. At inflammatory processes the forecast to a large extent depends on the accompanying disturbances of circulation of cerebrospinal liquid. The forecast at parasitic defeats is defined by plurality of defeat and extent of the accompanying inflammatory and adhesive processes in ventricles and covers of a brain.
Bibliography: The multivolume guide to neurology, under the editorship of S. N. Daviden-kov, t. 5, M., 1961; The Multivolume guide to surgery, under the editorship of B. V. Petrovsky, t. 3, book 2, M., 1968; Petten B. M. Embryology of the person, the lane with English, M., 1959; Sheliya R. N. Tumors of ventricular system of a brain, L., 1973; G 1 and and M. of Das Nerven-system des Menschen, Lpz., 1953; G o r-rales M. T o r r e and 1 b a G. The third ventricle, Normal anatomy and changes in some pathological conditions, Neuroradiology, v. 11, p. 271, 1976, bibliogr.; Messert B., Wanna-maker B. B. a. Dudley A. W. Reevaluation of the size of the laterol ventricles of the brain, Postmortem study of an adult population, Neurology (Min-neap.), v. 22, p. 941, 1972.
E. P. Kononova, S. S. Mikhaylov; H. Ya. Vasin (neyrokhir.).