MENINX

From Big Medical Encyclopedia

MENINX [meninges (PNA, JNA, BNA)] — the connective tissue filmy educations covering a head and spinal cord. Distinguish firm cover brain (dura mater encephali, PNA, BNA; pachymeninx, JNA) and spinal cord (dura mater spinalis), arachnoid membrane brain [arachnoidea (mater) encephali] and spinal cord [arachnoidea (mater) spinalis], soft (vascular) cover brain (pia mater encephali) and spinal cord (pia mater spinalis). Each of the listed covers makes a whole and from a brain passes to back.

Anatomy

Fig. 1. A habit view of a firm cover of a brain and its shoots (tissue of a brain is removed, bones of a skullcap are removed partially): 1 — a firm cover in an average cranial pole; 2 — a falx cerebri; 3 — the place of an attachment of a falx cerebri to a namet of a cerebellum; 4 — it is mashed a cerebellum; 5 — a dorsum sellae; 6 — a funnel of a hypophysis; 7 — a diaphragm of a saddle; 8 — a round opening; 9 — a firm cover in a front cranial pole.

Firm cover of a brain dense consistence, prilezhit to an inner surface of bones of a skull. Its thickness in the field of the arch makes 0,7 — 1 mm, and on a base of skull — 0,2 — 0,5 mm. In the field of openings, vascular furrows, ledges and seams, on the most part of a base of skull it densely grows together with cranial bones, in other sites is connected more rykhlo. At patol, states it can exfoliate, and then between it and an inner surface of bones there is a crack — a so-called epidural space; at injury of bones of a skull epidural hematomas can be formed here. Inner surface of a firm cover of a brain smooth. It rykhlo is connected to the subject arachnoid membrane multilayer accumulation of special cells, rare connective tissue threads, thin vascular stipitates and nerves, and in nek-ry places — pakhionovy granulations of an arachnoid membrane (see. Arachnoidal granulations ). Between firm and web covers normal there is no crack. The firm cover of a brain is stratified by places on two leaves, between to-rymi venous sine and a trigeminal cavity (cavum trigeminale) where the trigeminal node is placed form. Between formations of a brain a number of shoots departs from a firm cover: the falx cerebri, is mashed also a falcula, a diaphragm of the Turkish saddle (fig. 1). The falx cerebri (falx cerebri) departs from a firm cover of the arch in the field of a furrow of an upper sagittal sine between hemicerebrums down. In front it is attached to a cock crest of a sievebone, and behind — to a crosswise eminence of an occipital bone where grows together with mashed a cerebellum. The bottom free edge of a shoot reaches a corpus collosum. Depending on a configuration of a skull the form and the sizes of a falx cerebri are various: at dolichocephalic persons is it extended, at brakhitsefal — more abrupt. Thickness of a falx cerebri — 0,7 — 0,9 mm, width — on average 3 — 3,5 cm, than a kpereda is less.

By Namet of a cerebellum (tentorium cerebelli) it is located horizontally, from sides it is attached to the upper edges of a pyramid of a temporal bone, in front — to the back inclined shoots, behind — to horizontal branches of a crosswise eminence. On the centerline it grows together from above with a falx cerebri, and below — with a falcula. Namet of a cerebellum has the form of a horseshoe of bigger or smaller length depending on a shape of a skull. From its median free edges cutting (incisura tentorii) forms, in a cut the stem department of a brain is located. Namet of a cerebellum separates occipital shares of hemicerebrums from a cerebellum. Length of cutting fluctuates within 4 — 6 cm, and width — 2 — 4 cm.

The falcula (falx cerebelli) is located in back cutting of a cerebellum. It begins from above from is mashed a cerebellum, lasts along an internal occipital crest and, having below reached a big occipital opening, covers it two legs.

The diaphragm of a saddle (diaphragma sellae) goes horizontally from lobbies and the back inclined shoots and covers from above the Turkish saddle. In the middle of a diaphragm there is an opening for a funnel of a hypophysis.

Fig. 2. Diagrammatic representation of venous sine of a firm cover of a brain: 1 — an upper sagittal sine; 2 — the lower sagittal sine; 3 — a cavernous sine; 4 — an anastomosis of an eye vein with an angular vein of the person; 5 — a malar; 6 — the lower stony sine; 7 — a sigmoid sine; 8 — an upper stony sine; 9 — a cross sine; 10 — a direct sine; 11 — the big vein of a brain (is cut off).
Fig. 3. Diagrammatic representation of a cavernous venous sine (frontal section of its back half): 1 — the back inclined shoot; 2 — a third cranial nerve; 3 — an internal carotid artery; 4 — block a nerve; 5 — a trabecula; 6 — an optic nerve; 7 — the taking-away nerve; 8 — a maxillary nerve; 9 — a hypophysis.

Sine of a firm cover (sinus durae matris, sinus venosi durales) — the channels formed by its splitting, usually in places of an attachment of a cover to bones of a skull. Walls of sine dense, are covered with an endothelium, not falling down from within that provides a free blood flow. K. D. Balyasov (1950) described in a cavity of sine various anatomic devices (trabeculas, partitions, valves) regulating the direction of a blood-groove. Allocate several sine (fig. 2). The cross sine (sinus transversus) — pair, is in the rear edge is mashed a cerebellum, in the furrow of an occipital bone of the same name; in front passes into the sigmoid sine (sinus sigmoideus) located in the furrow of an occipital bone of the same name and opening in a bulb of an internal jugular vein. Upper sagittal sine (sinus sagittalis sup.) — unpaired, passes across the centerline of a calvaria in the furrow of the same name from a cock crest where veins of a nasal cavity fall into it, to an internal occipital ledge and connects to a cross sine. Sidewalls of a sine have the numerous openings connecting it to side lacunas (lacunae lat.), in to-rye superficial brain veins fall. Lower sagittal sine (sinus sagittalis inf.) is located in the bottom free edge of a falx cerebri; falls into a direct sine (sinus rectus) — unpaired, taking place in the conjunction of a falx cerebri with mashed a cerebellum. In front in it the big vein of a brain opens, behind the sine connects to a cross sine. The occipital sine (sinus occipitalis) — unpaired, small, lies in a falcula along an internal occipital crest. At the rear edge of a big occipital opening it forks. Its branches surround an opening and fall into a sigmoid sine. In the field of a slope of an occipital bone in the thickness of a firm cover the basilar veniplex (plexus venosus basilaris) connecting to occipital, lower stony, cavernous sine and an internal venous vertebral texture lies. The conjunction cross, upper sagittal, direct and occipital sine is located at an internal occipital ledge and is called a sinus drain (confluens sinuum). Top and bottom stony sine (sinus petrosi sup. et inf.) — steam rooms, pass along the furrows of the same name. They connect sigmoid and cavernous sine. The cavernous sine (sinus cavernosus) — pair, the most difficult on a structure, lies on the parties of the Turkish saddle. In his cavity the internal carotid artery, and in an outside wall the first branch of the V cranial nerve, and also III, IV, VI cranial nerves (fig. 3) is located. The cavernous sine is connected with unpaired front and back intercavernous sine (sinus intercavernosi ant. et post.). Damages of the internal carotid artery which is in a cavity of a sine create anatomic conditions for formation of arteriovenous sleepy and cavernous aneurisms (the pulsing exophthalmos). The wedge-shaped and parietal sine (sinus sphenoparietalis) lies at the edges of small wings of a wedge-shaped bone; opens in a cavernous sine. Venous sine have a numerous anastomosis, on the Crimea roundabout outflow of blood from a head cavity is possible, passing an internal jugular vein. The cavernous sine by means of a veniplex of the sleepy channel surrounding an internal carotid artery is connected to veins of a neck, through veniplexes of round and oval openings — to an alate veniplex, and through orbital veins — to veins of the person. The upper sagittal sine has a numerous anastomosis with parietal emissarny veins, diploichesky veins and veins of a calvaria. The sigmoid sine is connected by mastoidal emissarny veins to veins of a nape. The cross sine has an anastomosis with veins of a nape by means of occipital emissarny veins.

Firm cover of a spinal cord more thinly than a firm cover of a brain; it forms the bag for all spinal cord which is coming to an end with narrowing at the S2-3 level. From a dural bag there is a thread of a firm cover of a spinal cord [filum (durae matris) spinale] which is attached to a tailbone down. The firm cover does not grow together with a periosteum of vertebral foramens, and between them the epidural space (cavitas epiduralis) filled with friable not properly executed connecting fabric and an internal venous vertebral texture is formed. The firm cover creates the fibrous vaginas passing on spinal nerves into an epineurium around roots of a spinal cord.

Arachnoid membrane — the thin, translucent avascular connective tissue plate surrounding a head and spinal cord. The arachnoid membrane of a brain is thrown through crinkles, without getting into depth of furrows and deepenings of a brain owing to what between it and the subject soft cover the subarachnoid (subarachnoidal) space (cavitas subarachnoidealis) filled with cerebrospinal liquid forms. In nek-ry sites it is expanded and forms subarachnoid (subarachnoidal) tanks (cisternae subarachnoideales). The arachnoid membrane of a spinal cord also limits the subarachnoid space containing cerebrospinal liquid, a cut in the bottom extends and forms the final tank (cisterna terminalis) where the horse tail lies. In other sites the arachnoid membrane and a soft cover are connected by a set of trabeculas.

Soft cover — a thin connective tissue plate, directly adjacent to a head and spinal cord. The soft cover of a brain completely corresponds to its relief and gets into all deepenings, takes part in formation of a basis of vascular textures of cerebral cavities (see. Vascular textures ). In its thickness the vascular network of a brain is located. In places of immersion of vessels in a brain the soft cover forms around them coverings, between to-rymi and substance of a brain perivascular cracks are found (see. Virkhova-Robena space ). However their reliability is called in question. It together with an arachnoid membrane covers cranial nerves to the place of an exit them from a skull, passing further in peri-and endonevriya. The soft cover of a spinal cord densely with it grows together, except the site of a front median crack.

Fig. 4. The diagrammatic representation of the site of a spinal cord with the opened covers: 1 — a soft cover; 2 and 4 — a firm cover; 3 — an arachnoid membrane; 5 — roots of spinal nerves.
Fig. 5. Diagrammatic representation of a backbone (cross section, dorsal view): 1 — a back root of a spinal cord; 2 — a gear sheaf; 3 — a ventral root of a spinal cord; 4 — a spinal node; 5 — a spinal nerve; 6 — a soft cover; 7 — subarachnoid space; 8 — an arachnoid membrane; 9 — a firm cover; 10 — a periosteum; 11 — an epidural space with an internal vertebral veniplex.

Between ventral and back roots it forms gear sheaves (ligg, denticulata) — the continuous tapes covered with an arachnoid membrane, going from a big occipital opening to L1 Gear sheaves are located frontally, on each side are divided into 18 — 25 teeth growing to a firm cover (fig. 4).

Fig. 6. Diagrammatic representation of a structure of covers of a brain (cross section): 1 — an upper sagittal sine; 2 — granulations of an arachnoid membrane; 3 — superficial veins of the arch; 4 — a parietal emissarny vein; 5 — a pole of granulation of an arachnoid membrane; 6 — granulation of an arachnoid membrane in a bone; 7 — a firm cover; 8 — an arachnoid membrane; At — subarachnoid space; 10 — a soft cover; 11 — bark of a hemicerebrum; 12 — a side lacuna of an upper sagittal sine and granulation of an arachnoid membrane in a lacuna; 13 — a parietal bone; 14 — diploichesky veins.

The intershell spaces

Between a periosteum of the vertebral channel and a firm cover there is an epidural space (fig. 5). Important funkts, and a wedge, the crack between web and soft covers — subarachnoid (subarachnoidal) space — cavitas subarachnoidealis (fig. 6), filled with cerebrospinal liquid (liquor cerebrospinalis) matters. In a subarachnoid space allocate the most considerable departments on volume — subarachnoidal tanks (cisternae subarachnoideales): mozzhechkovomozgovy (cisterna cerebellomedullaris), located between a lower surface of a cerebellum and a medulla; tank of a lateralgy pole of a great brain (cisterna fossae lateralis cerebri); the tank of decussation (cisterna chiasmatis) — ahead of visual decussation; the intercrural tank (cisterna interpeduncularis) — between legs of a brain. The subarachnoid space is reported with cerebral cavities by means of the located in a back wall of the fourth ventricle median and lateral apertures — aperturae mediana et lateralis ventriculi quarti (the first of them was called Marangdi's opening, the second earlier — Lushki's opening).

In it the brain vessels which are in more thickly soft cover will stand. The subarachnoid space of a brain through a big occipital opening passes into subarachnoid space of a spinal cord. On modern representations, free subdural the space does not exist.

Blood supply and innervation

Fig. 7. The diagrammatic representation of vascular network of a firm cover of a brain of the person (according to N. Ya. Vasin): 1 — an outside capillary network; 2 — arteriovenous network; 3 — an internal capillary network.
Fig. 8. Macrodrug of a firm cover of a brain with the injected upper sagittal sine (in the center), its side lacunas and the shell veins.

Firm cover. The main shell arteries of a brain are: average (a. meningea media) from a maxillary artery (a. maxillaris), a lobby (a. meningea ant.) from a lobby trellised (a. ethmoidalis ant.), back (. meningea post.) from ascending pharyngeal (a. pharyngea ascendens). Besides, the shell branches approach a firm cover (rr. meningei) from the lacrimal artery (and. lacrimalis). stylomastoid (. stylomastoidea), occipital (. occipitalis), internal sleepy (. carotis int.), vertebral (. vertebralis). The listed shell arteries and branches form shirokopetlisty arterial network in a firm cover, from a cut there are to outside and internal plates of a cover small arteries creating arteriolo - capillary venulyarnye networks (fig. 7). Outflow of a venous blood comes from a capillary bed of a firm cover on the shell veins: to lobbies (vv. meningeae ant.) in an internal jugular vein, an average (vv. meningeae med.) in an alate veniplex and back (vv. meningeae post.) in veins of a nape. Veins of a firm cover as well as arteries, form the venous network close to arterial in deep layers of an outside plate of a cover.

The network has an anastomosis with diploichesky veins and venous sine (fig. 8). The firm cover of a spinal cord vascularizes from spinal branches (rr. spinales) of vertebrata (aa. vertebrales), back branches (rr. dorsales) back intercostal (aa. intercostales post.), subcostal (aa. subcostales) and lumbar (aa. lumbales) arteries. Outflow of blood happens on spinal veins (vv. spinales) in an internal venous vertebral texture, and also in back intercostal (vv. intercostales post.) and lumbar veins (vv. lumbales).

Limf, vessels in a firm cover are not revealed. Sources of an innervation of a firm cover of a brain are V, VI, IX, X, XI, XII pairs of cranial nerves, and also three upper couples of cervical spinal ganglions and sympathetic nerves suitable to a cover as a part of neuroplexes. V. L. Lesnitskaya showed that density and an order of an arrangement of the shell nerves have certain distinctions. The shell nerves create two neuroplexes: more powerful in an outside plate and thinner in internal. In a cover numerous nerve terminations are described: receptors with diffusion branching and poorly developed neuroglial component and compact treelike receptors with short terminalyam and well developed neuroglial component, estimated as baroreceptors. Vascular fabric receptors meet, to-rye take for chemoceptors. Existence in a cover of neuroplexes and a large number of receptors allows to consider a firm cover as an intracranial reflexogenic zone.

The shell branches are a source of an innervation of a firm cover of a spinal cord (rr. meningei) of spinal nerves and branches of sympathetic trunks. Besides, V. I. Zyablov (1966) showed participation in an innervation of a firm cover of vagus nerves. The nervous branches suitable to a cover form superficial and deep neuroplexes, sensory nervous cells and receptors in the form of the free low-branching widespread arborization.

Web and soft covers. Arachnoid membrane of a head and spinal cord avascular. The soft cover of a brain possesses well-marked capillary networks, sources of formation to-rykh branches of brain arteries are. Outflow of blood comes from a soft cover in brain veins. The soft cover of a spinal cord also has the capillary networks created by branchings of spinal branches.

Limf, is not present vessels in web and soft covers. The innervation of web and soft covers of a brain is carried out by branches of the III—XII pairs of cranial nerves, and also sympathetic branches of internal sleepy and vertebral textures, to-rye form neuroplexes around brain arteries. Posterior pyramids of fibers, the innervating covers depart from them. Receptors, similar to the terminations of a firm cover, and also sensory nervous cells are found in these covers.

The histology

the Histogenesis

Most of embryologists believes that M. of the lake form at the expense of elements of two germinal leaves — mesoderms and ectoderms: a firm cover — only from a mesenchyma, web and soft covers — from a mesenchyma and ectodermal elements of a neurotubule. The perimedullary mesenchyma rather early (at embryos of 4 — 5-mm length, 4 weeks) is differentiated on two layers — outside skeletogenous, from to-rogo cover bones of a skull, and internal — primary meninx (meninx primitiva) are stuffed up. This cover at embryos of 12 — 19 mm (6 — 7 weeks) is stratified on outside (ectomeninx) and internal (endomeninx) leaves. The outside leaf at embryos of 3 months is differentiated on a periblast — an internal periosteum of bones of a skull (lamina interna periostealis) and on a firm cover (dura mater craniospinalis). The internal leaf, in turn, is stratified on an arachnoid membrane [arachnoidea (mater) craniospinalis] and a soft cover [pia (mater) craniospinalis]. At the expense of an endomeninks trabeculas and cells of subarachnoid space (reticulum arachnoideum) and a vascular basis (tela chorioidea) are formed. Besides, web and soft covers receive coverings from epithelial cells, to-rye, according to A. G. Knorre (1967), have a neyralny origin.

Migration in an internal leaf of cells from ectodermal laying of a medullary tube and from a nodal plate is confirmed by Stanek (J. Stanek, 1977).

Structure of covers

Firm cover — the lamellar education consisting of rather thick bunches of collagenic fibers and more posterior and rare pyramids of the elastic fibers skintight to each other forming network and oriented in various directions that causes the considerable durability and elasticity of a cover. In a cover distinguish two plates: outside fibrous (lamina fibrosa ext.) and internal fibrous (lamina fibrosa int.). In an outside fibrous plate arteriolo - capillary venulyarnaya the network is presented by arterioles to dia. 20 microns at capillaries to dia. 7 — 9 microns and venules to dia. 15 — 50 microns. In an internal fibrous plate elements of drainage system prevail. Arterioles have the same diameter, capillaries — 10 — 12 microns, and venules — 50 — 100 microns. The quantity contained in the main substance cementing collagenic and elastic fibers, mucopolysaccharides increases in those sites of a firm cover, in to-rykh a capillary network is less dense, and bunches of collagenic fibers are larger and are more densely located. Between bunches of collagenic fibers cellular elements are located: fibroblasts and fibrocytes, settled macrophagocytes (histiocytes) and free macrophagocytes. The firm cover of a spinal cord is thinner, consists also of two plates, in them elastic fibers prevail. The capillary network in it is more rare (density of capillaries 19,1 ± 0,5 in 1 mm 2 ), though the venulyarno-arteriolar coefficient is rather high (3,7 ± 0,12).

The inner surface of a firm cover is covered with a boundary layer of the flat branching cells located on a dense collagenic basis.

The subdural space is formed only at patol, states, napr, at subdural hematomas. Andres (To. Andres, 1967), Split and Izard (M. Rascol a. J. Izard, 1976), Shakhenmayr and to Frida (W. Schachenmayr a. R. L. Friede, 1978) showed that between firm and web covers at the person (as well as at mammals) multilayer cellular education (2 — 8 layers) is located, in extracellular spaces to-rogo there are no connective tissue fibers. This education is called a subdural neuroepithelium.

Fig. 9. Diagrammatic representation of a microscopic structure of covers of a brain: I \a firm cover, II — a layer of a subdural neuroepithelium, III — an arachnoid membrane, IV — subarachnoid space, V — a soft cover; 1 — a brain artery; 2 — trabeculas subarachnoid spaces; 3 — a neuroepithelial cell of a subdural layer; 4 — a histiocyte; 5 — a fibroblast; 6 — cross-section of bunches of collagenic fibers; 7 — longitudinal bunches of collagenic fibers.

The deep zone of a neuroepithelium separates from an arachnoid membrane by means of the basal plate having thickness of 30 — 45 nanometers. Cells connect by means of desmosomes. There is a set of tonofibrils. The border between a firm cover and a neuroepithelium a twisting, but basal plate is absent; on the contrary, characteristic connections of a neuroepithelium with fibroblasts and collagenic fibers of a firm cover (fig. 9) are visible. At formation of subdural hematomas there is a proliferation of boundary cells of a firm cover and formation of the subdural neomembranes limiting a hematoma.

Fig. 10. The diagrammatic representation of web and soft covers of a brain with likvoronosny channels of subarachnoid space (according to M. A. Baron): 1 — an arachnoid membrane; 2 — the «stars» formed by the collagenic fibers departing from an arachnoid membrane; 3 — the likvoronosny channel (a view from a surface of a cover); 4 — cells of subarachnoid space; 5 — the likvoronosny channel; 6 — a brain artery and the branches departing from it in the channel; 7 — the trabeculas fixing an artery in subarachnoid space; 8 — Virkhov's space — Robena; 9 — a soft cover; 10 — a brain.

Arachnoid membrane — the thin coat of friable fibrous connecting fabric, contains several layers: outside cellular layer of an endothelium (arakhnoidendoteliya); a layer of the argyrophil and collagenic fibers making a stroma of an arachnoid membrane (stroma arachnoideae); inner cellular layer of an endothelium (arakhnoidendoteliya). On an outer surface of an arachnoid membrane the endothelium forms accumulations of various volume and the sizes: cellular spots (maculae cellulares), cellular hillocks (colliculi cellulares), arachnoidal granulations (granulationes arachnoideales). Numerous arachnoidal trabeculas — crossbeams (trabeculae arachnoideales) depart from the inner layer of an arachnoid membrane to a soft cover and vessels lying in it, to-rye give to subarachnoid space a cellular look. Trabeculas are outside covered with an endothelium. Merges of cells create the likvoronosny channels (fig. 10) described by M. A. Baron. The arachnoid membrane of a spinal cord is slightly thinner, but has a similar structure and forms arachnoidal granulations.

Soft cover directly prilezhit to a brain and it is delimited from it by an outer glial membrane (membrana gliae ext.). It consists of two plates: outside (lamina ext.), covered with endoteliopodobny cells, and internal (lamina int.), between to-rymi brain arteries and veins lie, eminating in subarachnoid space. In plates of a soft cover there are collagenic fibers and cellular elements: fibroblasts, macrophagocytes, plasmocytes, lymphocytes and pigment cells.

The physiology

Funkts, M.'s role of the lake comes down in general to ensuring life activity of c. N of page. Their researches fiziol, indicate values a zashchitnotrofichesky role and participation in regulation of a brain blood-groove, especially vessels of a soft meninx. M of the lake are biol, a barrier. The cellular elements of connecting fabric which are in them, especially macrophagocytes, possess the expressed phagocytal action (see. Phagocytosis ).

Fig. 11. Kimogramma of breath, venous and arterial pressure at irritation of a firm cover of a brain of a dog current: curves of initiation of breath (1), increase in venous pressure (2), lowering of arterial pressure in the general sleepy (3) and femoral (4) arteries; 5 — an otmetchik of time; 6 — an otmetchik of action of current.

Cells of a firm cover vividly react to pathological processes with formation of cellular accumulations and films around the centers and implants. M islands create around a brain the closed cavity filled with cerebrospinal liquid that protects it from damages. Cerebrospinal liquid (see), developed by vascular textures of ventricles, comes through apertures of the fourth ventricle to a subarachnoid space from where with the participation of an arachnoid membrane gets into a layer of a subdural neuroepithelium and it rezorbirutsya by powerfully developed kapillyarovenulyarny network of an internal fibrous plate of a firm cover. The firm cover is the important reflexogenic zone concerning maintenance of a fixed level intracranial pressure (see). S. S. Bryusova (1931), D. A. Biryukov (1948), A. M. Ugolev and V. M. Hayutin (1948) in experiments found depressor or pressor depressory reaction of the general ABP and venous pressure and stimulation of breath in response to irritation of a firm cover (fig. 11). The irritation of a firm cover exerts impact and on a brain blood stream.

The arrangement of an internal carotid artery in a cavity of a cavernous sine causes change of venous pressure in a sine at the pulse movements in an artery that plays an important physiological role in ensuring outflow of a venous blood from a head cavity. M. A. Sreseli and O. P. Bolshakov (1962) experiments showed that the cavernous sine promotes the movement of a venous blood in all system of sine, being some kind of «venous heart».

Pathology

Malformations of a meninx meet rather seldom and are usually combined with malformations of a head and spinal cord. They are shown by a local underdevelopment or splitting of a firm cover. Through its defects most often eminate soft covers and a brain (see. Brain, hernias ). Treatment of malformations, as a rule, operational. It is directed to closing of defects of M. of the lake and an opening in a skull.

Damages of a meninx can be observed at the opened and closed craniocereberal injury. At most of patients with effects of a craniocereberal injury the thickening firm and soft covers, their union with a cerebral cortex comes to light. In series of observations there are numerous subarachnoidal cysts, brain hems, to-rye can extend in white matter. A shell and brain hem — the major pathogenetic factor of epileptic seizures after a craniocereberal injury. At disturbance of an integrity of a cribriform plate and firm and web covers, adjacent to it, there is nasal Liquorrhea (see).

Most often the indication to operation after an injury of covers are epileptic seizures. In the presence of cicatricial unions between covers and a brain make meningoentsefaloliz and excision of a shell and brain hem with the subsequent step-by-step closing of defect of a firm cover and bones of a skull. At a nasal liquorrhea plastics of a firm cover and a crack of a base of skull for the purpose of dissociation of a subdural space from a nasal cavity is most reasonable.

Vascular defeats of a meninx are most often shown by hemorrhages in them. They can be are caused by a hypertension, aneurism, an infectious vasculitis, M.'s angiomatosis of the lake. Most often hemorrhages in soft covers meet. The major diagnostic character — availability of blood in cerebrospinal liquid. Also intradural hemorrhages are observed. An outcome of subarachnoidal and subpialny hemorrhages are secondary adhesive processes in covers, sometimes with the advent of symptoms of focal irritation of M. of the lake and a brain.

The main method of treatment of subarachnoidal hemorrhages — unloading spinal punctures, insufflations of oxygen. Indications to operational treatment arise seldom and are defined by the size of hemorrhage, its effects (epileptic seizures, the phenomena of a compression).

Inflammation of a meninx — meningitis, most often has an infectious and toxic etiology. Allocate pachymeningitis (see) — an inflammation of a firm cover and a pia-arachnitis — an inflammation of soft covers (see. Meningitis ).

Purulent forms of a pachymeningitis have limited character more often and can be followed by formation of extra-and intradural abscesses. The serous and hemorrhagic pachymeningitis most often occurs among not purulent forms.

There are messages on a possibility of development of subdural exudates both in the acute period of meningitis, and 2 — 6 months later after its termination. According to D. I. Drankin, H. To R. Ivanov, M. V. Godlevskaya (1975), the main reason for an exudate — a cerebral collapse. The spinal pachymeningitis is divided on outside and internal. The outside pachymeningitis (the peripachymeningitis, or epidurit) is always followed by transition of an inflammation to epidural cellulose and happens purulent, serofibrinous and hyperplastic. These forms can lead to a compression of a spinal cord and roots granulyatsionny fabric, cicatricial changes or a thickening of a cover.

At a pia-arachnitis the hl is surprised. obr. soft cover. Arachnoiditis (see) it is characterized by a preferential inflammation of an arachnoid membrane, happens limited and diffusion, cystous, adhesive, adhesive and cystous, ossifying. B. N. Pil (1977) emphasizes that at a cerebral pia-arachnitis diffusion inflammatory process in covers of a brain, an ependyma and a molecular layer of bark is found. After an inflammation of a meninx the residual phenomena in the form of adhesive process, commissures between covers, cysts, hydrocephaly are in most cases observed. Shell and brain unions and cysts are the leading origin of epileptic seizures, development of occlusion of likvorny ways, defeats of visual decussation (hiazma).

The edema developing at a chronic pia-arachnitis can be arezorbtivny and occlusal (see. Hydrocephaly ). The Arezorbtivny edema is caused by disturbance of absorption of cerebrospinal liquid as on an outside, and inner surface of a brain. Occlusal hydrocephaly arises owing to disturbance of outflow of cerebrospinal liquid from cerebral cavities in a subarachnoid space.

Diagnose inflammatory diseases of M. of the lake and their effect on the basis of features a wedge, pictures, the beginnings and courses of a disease, inflammatory changes of cerebrospinal liquid, blood, contrast methods of a research.

One of important pnevmoentsefalografichesky symptoms at a pia-arachnitis are delay of absorption of air from ventricular system, change of the drawing of the subshell spaces (not filling or cystous expansion).

The internal and outside reported edema are characterized by expansion of ventricles and subarachnoid spaces. At an optokhiazmalny arachnoiditis are not filled or are not completely filled the tank of decussation (optokhiazmalny) and intercrural tank.

At inflammatory process in M. complex antiinflammatory therapy is shown to the lake. Indications to operation arise at development of Epi - and intradural abscesses, accumulation subdural an exudate, shell and brain hems, cysts with a syndrome of focal damage of a brain, threat of a blindness at an optokhiazmalny arachnoiditis, a syndrome of a compression of a spinal cord and roots. A main objective of operation at konveksitalny, optokhiazmalny and spinal arachnoidites is removal or separation of the shell unions, hems, the cysts injuring or causing a compression of brain fabric.

The direct indication for operational treatment of hydrocephaly is progressive increase in the head of the child or development of a gipertenzionny syndrome at inefficiency of antiinflammatory and dehydrational therapy. At occlusal hydrocephaly of operation are directed to recovery of circulation of cerebrospinal liquid, elimination of occlusion or creation of new channels of outflow of liquid. The operations of separation of commissures offered earlier between almonds of a cerebellum and a trunk in the field of a median aperture of the fourth ventricle (Marangdi's opening) are a little effective because of an aggravation of inflammatory process and a recurrence of occlusion. Operation of a section of a worm of a cerebellum at low occlusion in the big tank is more effective, however after this operation closing with commissures of an opening in a dissect worm is also possible. Especially widely at occlusal hydrocephaly the bilateral ventrikulo-tsisternostomiya by means of the drainage tubes which are taking away cerebrospinal liquid from back horns of side ventricles in the big tank of a cerebellum is applied. At arezorbtivny hydrocephaly at children make operations of a ventrikuloatriostomiya and a ventrikuloperitoneostomiya (see. Hydrocephaly ).

A main objective of operation at a spinal arachnoiditis, an epidurita is recovery of passability of subarachnoid spaces, elimination of a compression of a spinal cord and roots.

Tumors

Covers of a brain can be surprised benign and malignant tumors. Arakhnoidendotelioma (meningioma) arise in a firm cover or its shoots and grow towards a brain, pushing aside its bark (see. Meningioma ). Arakhnoidendotelialny accumulations of cells in a firm cover consider as a possible source of development of meningiomas. In covers of a brain the angiomatosis — overdevelopment of vessels can be observed. More often he is local, sometimes reflection of a system angiomatosis (see. Gippelya-Lindau disease ).

Malignant tumors most often affect M. with the lake in the metastatic way. I. S. Babchin, I. P. Babchina, V. R. Kalkun (1974) specify that not only metastatic process, but also primary horioidepitelialny cancer with the subsequent distribution on soft covers can develop in M. of the lake. Both in soft, and in firm M. three forms of metastasises can be observed by the lake: single nodes, multiple nodes, diffusion distribution of cancer cells.

M.'s sarcoma of the lake can also be diffusion or in the form of nodes. In some cases the subject tissue of a brain is surprised. Innidiation of melanomas in the form of a wide spread occurance of complexes of tumor cells in subarachnoid spaces and intra adventitious cracks of vessels of a brain is sometimes observed.

Diagnosis of defeat of M. of the lake malignant tumors is based on the accounting of expressiveness of a meningeal syndrome with loss of function of cranial nerves, the phenomena of intoxication, existence of malignant cells in cerebrospinal liquid.

The limited tumor is subject to operational removal. At diffusion defeats of covers malignant tumors apply radiation therapy. Also radioisotopes are used, to-rye enter into ventricular system and subarachnoid spaces. The combined treatment of metastatic defeat of a meninx consists in use beam and chemotherapy in combination with hormonal drugs.

Plastics of a firm cover

Any a head and spinal cord operation is usually completed careful recovery of tightness of a subdural space. However in some cases it is not possible to sew up a firm cover, and it can conduct to a liquorrhea, inf. to complications, prolapse of a brain, formation of hems, etc. The important role of plastic

substitution of defects of a firm cover is defined by it. The plastics is shown also at impossibility of closing of the defect which was result of an extensive craniocereberal injury during the closing of likvorny fistula after basal and parabasal damages, at a spinal cord operations when mending of a firm cover quite often also is impossible or undesirable, etc. Operation is contraindicated in the presence of strong indications of infection of a wound.

Fig. 12. Diagrammatic representation of some types of plastic surgeries of substitution of defect of a firm meninx: and — plastics the split autoobolochka across Bryuningu — Burdenko; — sutural fixing of a transplant; in — glue fixing of a transplant (the autoobolochka and a transplant are specified by an arrow).

Closing of defects of a firm cover by means of artificial and synthetics gained distribution: polyethylene, polyvinylalcohol, capron etc., to-rye, however, concede biol, to fabrics. Explant is strengthened frequent seams on a circle of defect of a firm cover. Apply autografts from an aponeurosis to closing of defects of a firm cover, a fascia of a temporal muscle, a wide fascia of a hip more often. In the best way the plastics of the shell defect proved as the fabric of the same name. At the known way of an autoplasty across Bryuningu — Burdenko use an outside leaf of a firm cover of the most sick (fig. 12, a). However this way is suitable for substitution only of small defects. The most acceptable material consider preserved (frozen, formalinizirovanny) a cadaveric firm cover. It is non-toxical also a maloantigenna, possesses a good vzhivlyaemost and mechanical strength, is impenetrable for cerebrospinal liquid and is steady against an infection. The cadaveric firm cover is easily prepared and can is long to be stored. After reorganization such transplant by outward and a structure is similar to a firm cover of the recipient.

The sutural way of fixing (fig. 12, b) over defect of the shell transplant is quite simple, but does not provide sufficient tightness of connection, especially at manipulations on the basis of a brain, and is very labor-consuming. These defects are eliminated during the use of a seamless (glue) method of compound of fabrics. For this purpose use medical glue on the basis of cyanoacryl to - you (MK-2, MK-6, etc.).

At defect of rather small sizes it is possible to be limited only to glue fixing of a transplant. In this case the rag of a tinned cover is found so that its edges came for edges of the shell defect on 1,5 — 2 cm (fig. 12, c). At the extent of defect of St. 10 cm 2 the combined, shovno-glue way of strengthening of a transplant is reasonable: in the beginning the rag of a tinned allogenic cover is attached 4 — 6 seams to a firm cover at the edges of defect, and then, having drained the connected surfaces, stick together them.

Fig. 13. The diagrammatic representation of stages of operation of a tamponade of the damaged venous sine of a firm meninx: and — the piece of a muscle is imposed on defect of a wall of a sine; — podshivany muscles in the field of defect of a wall of a sine; in — types of the applied seams.

Plastic surgery can be an effective remedy of fight against bleeding from the damaged venous sine of a firm cover when preservation of its passability is necessary. At small linear gaps bleeding is rather easily stopped the piece of a muscle stacked on defect (fig. 13, a). Defects of a wall of a sine of more considerable sizes demand strengthening of a muscular transplant seams (fig. 13, c) or medical glue; the place of damage is in addition covered with the split shell rag (across Bryuningu — Burdenko) or a tinned allogenic shell transplant.



Bibliography: Baron M. A. Reactive structures of internal covers (serous, brain, synovial, endocardium and amnion), L., 1949; Bekov D. B. and Mikhaylov S. S. Atlas of arteries and veins of a brain of the person, M., 1979; Burdenko N. N. Collected works, t. 5, page 175, M., 1950; In about t and N-c of e in V. A. Functional morphology of venous formations of a firm meninx, Arkh. annate., gistol, and embriol., t. 46, No. 2, page 76, 1964; D r and N to and D. I. N, Ivanov H. River and Godlevskaya M. V. of Meningoye^okkovaya infection, Saratov, 1975; Constants and N about in with to and y G. A. O nervous cells of a soft cover of a brain, Arkh. annate., gistol, and embriol., t. 63, No. 7, page 92, 1972; Mikhaylov. Page and With p e with e of l and M. A. Functional anatomy of venous sine of a firm meninx of a brain of the person, in the same place, t. 58, No. 7, page 3, 1970; Motavkinp. And., Karedinav. Page to them ukhinag. M. Holin - and adrenergic components of a vegetative innervation of a firm meninx, in the same place, t. 70, No. 1, page 36, 1976; Pil B. N. Diagnosis of chronic inflammatory diseases of covers of a brain, L., 1977; The Guide to neurotraumatology, under the editorship of A. I. Arutyunov, p.1, page 359, M., 1978; With t and N of e to Y. Embriologiya of the person, the lane with slovatsk., page 383, Bratislava, 1977; At r yu m about in V. M., In and with to and I. S. N and And r and to about in L. V. Operational neurosurgery, page 113, L., 1959; R a s with about 1 M. a. I s and of d J. The subdural neurothelium of the cranial meningos in man, Anat. Rec., v. 186, p. 429, 1976; they, Arachnoi-den and subarachnoid spaces of the vault of skull in man, Acta neuropath. (BerL), v. 41, p. 41, 1978; S with h a with h e n m a y r W. F r i e d e R. L. The origin of subdural neomembranes, Amer. J. Path., v. 92, p. 53, 1978.


O. A. Laponogov; L. Ya. Livshits (neyrokhir.), S. S. Mikhaylov (An.).

Яндекс.Метрика