SPINAL CORD [medulla spinalis (PNA,JNA, BNA)] — the most ancient lower (back) part of the central nervous system located in the vertebral channel and surrounded with a meninx.
The COMPARATIVE ANATOMY
the Central nervous system in a primitive form is presented at S.'s lancelet of m, having an appearance of a tube of irregular shape, edges is located throughout all trunk. Roots depart from S. of m front, or ventral (motive), and back, or dorsal (sensitive). Spinal nodes are absent, and sensory bipolar cells are located both in dorsal departments of S. of m, and on the course of sensory nerves.
In S. the m of Cyclostoma plans division into the central part (gray matter) containing cells, and surrounding it the peripheral part consisting from longwise the located amyelenic fibers. Dorsal roots have the spinal nodes presented by diaxones.
The page of m of Selachii is S.'s prototype of m of the highest animals. Due to the miyelirshzation of nerve fibrils in it sharp separation of gray and white matter is observed; ventral and dorsal horns of gray matter, ventral and side cords in white matter C. of m form, there is a merge of ventral and dorsal roots to formation of the mixed nerves.
Amphibians with development of extremities have cervical and lumbar thickenings of S. of m. In gray matter C. of m also the lateral group of cells of front horns is allocated medial, and at the level of thickenings. Neurons of spinal nodes at amphibiouses become pseudo-unipolar; their central shoots in back cords of S. of m form the descending and ascending ways, however the last do not reach a brain yet. In S. the m of bony fishes developed the ascending ways to a brain trunk and a cerebellum being in ventral and side cords; the dorsal sensitive way and the descending bonds begins to form. Reptiles and birds have a further differentiation of cellular and fiber structures
of S. of m, associative neurons are differentiated, intersegmental and komissuralny bonds develop. At birds bilateral ties of S. of m with a cerebellum and a vestibular mechanism are well developed.
The page of m of mammals has nek-ry morfol. features inherent in separate animal species. E.g., depending on number of vertebrae, function of extremities, existence or lack of a tail of S. of m has the different length and various quantity of segments, unequal expressiveness of thickenings, etc. S. in m of mammals differs from S. in m of reptiles and birds bigger differentiation of gray and white matter. In back horns (columns) substance and a chest kernel (a chest column, or Clark's kernel) appear jellylike (gelatinous, or rolandovo); in lobbies cellular groups clearly are allocated. Considerable development is reached by the neurons forming intersegment and komissuralny bonds, the number of fibers increases in back or dorsal cords, there is a new ascending way from cervical segments to an olive kernel. The most characteristic feature of ontogenesis of S. of m of mammals is the emergence of a korkovospinnomozgovy (pyramidal) way testimonial of a new stage of evolution of structure and function C. of m — about its korti-kolization. The pyramidal system reaches the highest development in subhuman primates and especially at the person.
Process of ontogenesis of S. of m repeats the main stages phylogenesis (see). At the person, as well as at all vertebrata, S. the m develops from a neuroectoderm. The medullary plate consisting of it, caving in, forms at first a nervous fillet, and then nervous (brain, medullary) a tube. From a medullary plate also ganglious plates (nervous combs) form; from them then neurons and a glia of spinal nodes are differentiated (see. Brain , comparative anatomy; Neuroglia ; Nervous system ).
Formation of a neurotubule is followed by structural change of its wall: from single-layer it as a result of reproduction of cells (medulloblasts) becomes multilayer. At an embryo on the 3rd week of development in a wall of a neurotubule allocate three layers: internal — ependimny, average — mantle (cover) and outside — regional (a regional veil). S.'s development by m happens from top to down: its cervical part ripens before underlying parts. Cellular elements of a cover layer the first find signs of a differentiation in two directions: one become the neuroblasts developing further in neurons, others — spongioblasts, from to-rykh there is a neuroglia. Nek-ry neuroblasts are differentiated very much early, others remain undifferentiated and, continuing to breed, cause accrescence of a cover layer. Spongioblasts create primitive to it-roglialny a skeleton, to-ry together with the developing neuroblasts forms gray matter C. of m. The last by the beginning of the 3rd month of an antenatal life gets a form of a butterfly on cross sections of S. of m, and in it it is already possible to allocate front, side and back horns (cornu). Axons of the developing neuroblasts of front horns of S. of m connect in ventral roots, in to-rye also shoots of cells of side horns from chest and upper lumbar segments C. of m enter. In the course of growth of a cover layer initial quite wide gleam of a neurotubule turns into narrow central channel C. of m; its vystilka, a definitivny ependyma, cells of an ependimny layer form. Nek-ry cells of this layer migrate in a cover layer and participate in formation of a neuroglial skeleton of gray matter.
The marginal layer (a regional veil) of a neurotubule gradually turns into white matter C. of m. It is connected, first, with a differentiation of ground mass of neuroblasts, shoots to-rykh form both own bunches of S. of m, and the ascending ways to a brain; and secondly, with growth from a brain of the descending ways. Myelination (see) conductors S. of m occurs in a certain sequence, in the same order, in what they arise in phylogenesis. On the 4th month of embryonic development fibers of back and ventral roots, by 5th month — own bunches of S. of m, after them (by 6th month) back spinnomozzhechkovy, preddverno-spinal and krasnoyaderno-spinal (by 7th month) ways are myelinized. In a front back and cerebellar way and in back cords the myelin cover appears before the birth.
The neuroblasts of spinal nodes developing from a ganglious plate have the bipolar form in the beginning; in process of a cell become pseudo-unipolar: their shoots seeming only are divided by T-shapedly into central (axons) and peripheral (dendrites) branches. The last together with fibers of ventral roots develop in the mixed spinal nerve, and the central branches gather in back roots and, having entered S. m, form its back cords. Spinal nodes are located in intervertebral foramens.
S.'s growth m in length lags behind the longitudinal growth of a backbone therefore the lower bound of S. of m is gradually displaced in the cranial direction. This process of «ascension» of S. of m continues also after the birth. On the 6th month of an antenatal life the lower bound of S. of m corresponds to the L5, U level of newborns — L3, U of adults — to the L1-2 level of vertebrae. Due to «ascension» of the developing S. of m the most part of its segments is located above the corresponding spinal nodes therefore the roots going to them are extended, • and roots of lumbar and sacral spinal nerves form a so-called horse tail.
At the beginning of S.'s development by m has identical diameter throughout except for the narrowed caudal department (a brain cone). Soon after education (on the 3rd month of development) kidneys of extremities two noticeable thickenings of S. of m appear: cervical and lumbosacral.
the Upper bound of S. of m of the person corresponds to decussation of pyramids (motor decussation, T.) or to an exit of the I couple of roots of spinal nerves it is also projected on edge of a big (occipital) opening. The page of m up without sharp borders passes in myelencephalon (see). At the level of
S.'s vertebrae of m terminates in a brain cone (conus medullaris) passing into terminal thread (filum terminale), edges it is attached to a tailbone at the level of Co2. S.'s length of m depends on human height. At newborn S. the m has length of 15 — 17 cm, by 10 years this indicator doubles. At the adult with a height of 168 cm S.'s length of m is equal to 41 — 45 cm. The weight (weight) of S. of m of newborns — 3,8 — 3,9 g, at children at the age of one year is 10,5 — 10,7 g, five years — 15 — 16 g; by 17 — 18 years of S. the m reaches usual weight — 26 — 28 g.
Conditionally in S. m allocate five parts: cervical, chest, lumbar, sacral and coccygeal (partes cervicalis, thoracica, lum-balis, sacralis et coccygea). The page of m forms two bends — cervical and chest, corresponding to bends of the vertebral channel (tsvetn. fig. 4).
The village of m has metamerism (see), edges it is shown in a segmented arrangement with a bilateralism of 31 — 33 couples of roots of spinal nerves. A segment consider S.'s piece of m corresponding to two couples of roots (fig. 1). In cervical part C. of m distinguish 8 segments (C1-8), in chest — 12 (Th1-12), in lumbar — 5 (L1-5), in sacral — 5 (S1-5) and in coccygeal — 1 — 3 (Co1-3). In cervical and lumbosacral parts C. of m there are thickenings (intumescentiae cervicalis et lumbo-sacralis) of the same name. The lower cervical segments (C5-8) and an upper chest segment (Th1) enter a cervical thickening. Are included all lumbar (L1-5) and two sacral (S1-2) of a segment in structure of a lumbosacral thickening. The cervical thickening is located in the vertebral channel at the C3-7 level, lumbosacral — at the level of Th10-12. The page of m has the cylindrical form with dominance of cross sectional dimension, to-ry in a chest part is equal to 10 mm, in the field of a cervical thickening — 12 — 14 mm, in lumbar and sacral parts — 11 — 13 mm.
Page of m throughout it is divided by a front median crack (fissura mediana ant. s. ventralis) and back median furrow (sulcus medianus post. s. dorsalis) on two symmetric half. Less deep lobbies and back lateral furrows (sulci anterolaterales, posterola-terales) correspond to an arrangement of ventral and back roots.
On cross section of S. of m distinguish gray matter, shaped butterflies, and the white matter surrounding it. A ratio of gray and white matter C. of m at its different levels unequally (fig. 2). Gray matter is divided into front and back horns (tsvetn. fig. 2). Throughout C8 segments — L3 gray matter C. of m forms protrusions — side horns (cornu lat.). At other levels side horns are presented by intermediate substance (substantia intermedia). In the center C. of m there is the central channel (canalis centralis). Conduction paths of S. of m (see. Conduction paths and tsvetn. fig. 3) are located in white matter where pair lobbies, side and back cords distinguish (funiculi ant., lat. et post.), divided from each party by ventral roots of spinal nerves and back horns of gray matter.
Page of m it is covered with a dense cover of a firm meninx, cover shoots («sleeves»), departing at each intervertebral foramen, cover spinal nodes (tsvetn. fig. 1). The space between a firm cover of S. of m and vertebrae (epidural space) is filled with a veniplex and fatty tissue. Except a firm meninx, S. the m is covered still with web and soft covers (see the Meninx). In the field of a big (occipital) opening of a cover of S. of m pass into a head cavity. Between soft and web covers of S. of m there is a subarachnoid (subarachnoid) space filled with cerebrospinal liquid (see). The firm cover of S. of m is connected to a soft cover symmetric tyazha, or the teeth forming a gear sheaf on S.'s longitudinal axis of m (lig. denticulatum). The gear sheaf divides a subarachnoid space into front and back departments.
Blood supply. Long ago it developed and it is long there was an idea that S. in m krovosnabzhatsya by three spinal (spinal) arteries (a lobby and two back) which are branches of an intracranial part of vertebral arteries. Was considered that spinal arteries, being located in a front median crack of S. of m and back lateral furrows, last from top to down along S. of m without being interrupted and at the level of each segment anastomose with radicular arteries, the Crimea the part only of the auxiliary (supporting) vessels was assigned.
The foundation of modern ideas of S.'s blood supply of m is laid in Adamkevich's works (A. Adam-kiewicz, 1882, 1898), V. N. Tonkova (1898), F. A. Rein (1908), Tanona (L. Tapop, 1908), etc. These researchers established that it is less radicular arteries, than segments C. of m and that not all of them participate in S.'s blood supply m. In the subsequent the big contribution to studying of blood supply of S. of m was made by N. I. An-gray (1919, 1922), M. M. Trostanets-ky (1924) who established that the number of the radicular arteries feeding front and back parts C. of m, unequally. Development of surgery of an aorta and other main vessels promoted studying of sources of blood supply of S. of m. In the 60th 20 century N. K. Bogolepov, D. K. Bogorodinsky, D. G. Hermann, Ya. Yu. Popelyansky, A. A. Skoromets, G. Lazorthes, Schneider (N. Schneider), Tsyulkh (To. J. Ziilch), etc. showed that on the lobby and back spinal arteries departing from vertebral arteries, blood arrives only to upper cervical segments (With X_IV), other segments of cervical department of S. of m are hit blood on front and back radikulomedullyarny (radicular) arteries. Radikulomedullyar-ny arteries are branches of the ascending cervical arteries (aa. cervicales ascendentes), costal and cervical trunk (truncus costocervica-lis), back intercostal (aa. intercostales post.), lumbar (aa. Jum-bales), lateral sacral (and. sacralis lat.) and iliolumbar (a. iliolumbalis) of arteries, entering the pool of an aorta. Radikulome-dullyarny arteries through intervertebral foramens are included into the vertebral canal and are divided into front and back branches; they krovosnabzhat S. of m, feed roots, spinal nodes and a meninx. Each such artery, having approached S.'s surface of m, is divided dichotomizing into the ascending and descending branches, to-rye connect to similar branches above and below the located radikulomedullyarny arteries and create along S. m front and two back arterial paths. A lobby and back spinal arteries, following in lengthwise direction, are interrupted, being, thus, only trailer branches of front and back radikulomedullyarny arteries. On the course of spinal longitudinal anastomotic paths there are sites with opposite directed blood-groove, napr, in the place of division of the main trunk of a radikulomedullyarny artery into the ascending and descending branches, and also in zones of a joint of two arterial pools.
The number of radikulomedullyarny arteries is subject to individual fluctuations and makes from 2 to 27 (more often 4 — 8) front arteries and from 6 to 28 (15 — 20 is more often) — back. There are two extreme types of a structure of the m of vessels feeding S. — main and loose. At the main blood supply of S. of m there is a small number of radikulomedullyarny arteries (3 — 5 lobbies and 6 — 8 back), at loose type of such arteries happens more (6 — 12 lobbies and 22 and more back). The superficial arterial network C. of m (vasocorona) formed by branches of radikulomedullyarny arteries, and also an anastomosis between spinal arteries is in a soft cover of S. of m.
The arterial network C. of m represents system of the pools of front and back radikulomedullyarny arteries connected and being one over another. The largest front radikulomedullyarny arteries (fig. 3) are available in srednesheyny department of S. of m (an artery of a cervical thickening) and in nizhnegrudny or verkhneioyasnichny department — a big front radikulomedullyarny artery (Adamkevich's artery). This artery is included into the vertebral canal with one of spinal roots (from Th2 to L5, is more often with any of Th9-12 of roots), usually at the left. Supply of chest and lumbosacral segments C. of m, except Adamkevich's artery, in 15 — 16% of cases is carried out by the lower additional radikulomedullyarny artery accompanying a root of L5 or S1. At the main type of a vaskulyarpzation of the lower half of S. of m, except Adamkevich's artery, sometimes there is an upper additional radikulomedullyarny artery suitable to S. for m with one of roots of Th3-6 segments. Thus, on a long axis C. of m it is possible to allocate two main arterial vascular pools. Upper — vertebrosubclavial (C1 segments — Th2-3) and lower — aortal (from Thm from top to bottom, including a brain cone). However the structure of vascular pools is variable. Lazort, e.g., allocates three vascular pools: upper, lower and intermediate (at the level of Th4-9 segments). The last is allocated as a zone, in a cut blood supply is less, than in top and bottom pools. During the studying of vascular system C. of m by a number of researchers the attention to existence of zones in S. of m was paid, to-rye a thicket suffer at vascular pathology; these zones (the levels C4, Th4, Th9 — L1) are located on joints of vascular pools. Tsyulkh (1954) called these zones critical and proved existence of critical ranges and on S.'s diameter of m.
The system of front radikulomedullyarny arteries by means of submersible branches of superficial arterial network supplies ventral 4/3 diameters of S. of m. The tail of diameter (1//5 part) is supplied with the branches of back radikulomedullyarny arteries getting into substance C. of m.
On features of a hemodynamics in S.'s diameter of m distinguish three zones of blood supply (fig. 4). The first of them covers a front horn, gray commissure, the basis of a back horn and sites of front and side cords adjoining to them. It is a so-called central arterial area. The second zone of blood supply is provided with submersible branches of back radikulomedullyarny arteries and occupies area of back cords and heads of back horns. The third zone — peripheral — receives blood from circular branches of a front spinal artery; it occupies regional sites of lobbies and side cords. Capillary networks of white and gray matter are various on density, a form of loops; also the angioarchitecture of capillary networks in various parts of columns gray and cords of white matter C. of m differs. Density of vascular network of gray matter is much bigger, than white.
From capillary intracerebral network C. of m blood is taken on radially located veins to venous network of a soft meninx, from there, on radicular veins — in internal vertebral veniplexes; from the last blood flows on intervertebral veins in various veins: on a neck — in vertebral and deep cervical, in chest and lumbar departments — in back intercostal and lumbar.
Nervous cells of S. of m (see. Nervous cell ) classify on the following groups: 1) the radicular cells presented by motor or efferent neurons (motor-neurons) of front and side horns; their shoots create ventral roots; 2) commissural cells, the localized hl. obr. in the basis of front horns; they provide komissuralny communication of both half of S. of m; 3) puchkovy cells; are available in all parts of gray matter, but are most numerous in side and back horns; axons form them intersegment bonds of S. of m, and also the ascending ways of side and front cords; 4) associative cells (interneyrona) located preferential in back horns and intermediate substance; axons connect zadnekoreshkovy fibers with motor neurons or puchkovy cells and the descending ways — with motor neurons of S. of m.
Neurons of front horns — motive, are located with groups (kernels), each of to-rykh innervates a certain group of muscles. Throughout S. of m the medial cellular group including anteromedial (nuci, ventromedialis) and zadnemedialny (nuci, dorsomedialis) kernels is well-marked; their neurons innervate muscles of a trunk. In the field of S.'s thickenings of m the kernels connected with an innervation of muscles of proximal departments of extremities are strongly developed a feather day lateral (nuci, ventrolateralis) and central (nuci, centralis). Muscles of a forearm and a shin are innervated from posterolateral (nuci, dorsolateralis), and muscles of a brush and foot — from zazadnelateralny (nuci, retrodorsolateralis) kernels. In front horns of C1-5 segments the spinal kernel of an eleventh cranial nerve is located (see), roots to-rogo leave S. of m between ventral and back roots of spinal nerves.
Motor (efferent) neurons — large multipole cells, the size of bodies to-rykh are reached by 40 — 60 microns, and in thickenings — 100 microns. They are supplied with long branched dendrites. The page of m contains apprx. 107 neurons, only 3% make motor-neurons of them. Consider that one motor-neuron has from 5 thousand to 25 — 35 thousand aksodendritichesky and aksosomatichesky synapses (see).
Side horns on an extent from a C8 segment to a L3 segment make a side intermediate column (columna intermediolatera-lis), to-ry contains the central sympathetic neurons — cells of an oval or spindle-shaped form from 12 to 45 microns; their dendrites branch in side horns, and axons are a part of ventral roots. Parasympathetic kernels are at the same place in S2-4 segments (nucll. parasympathici sacrales), shoots of cells to-rykh also leave through ventral roots, representing preganglionic parasympathetic fibers. In the central intermediate substance (substantia intermedia centralis) nervous cells are grouped in a kernel, originative to the front way crossed back cerebellar (tr. spinocerebellaris ant.). Is in lateral departments of side horns (columns) reticular formation (see) a spinal cord. Cells have it the long not numerous and low-branching dendrites.
In the center of back horns cells of own kernel are located (nuci, proprius cornuum post.); the majority of their axons create a spinotalamichesky way on the opposite side of S. of m (tr. spinothalamicus). In the basis of a back horn the chest kernel lies (a chest column, or Clark's kernel; columna thoracica s. nuci, thoracicus), the most expressed in chest
part C. of m; axons of cells of this kernel form not crossed back back and cerebellar way (tr. spinoce-rebellaris post.). The top of a back horn is adjoined behind by jellylike substance (substantia gelatinosa) presented by numerous small cells, to-rye are associative. Dorsalny spongy substance and a border area (the fringe region of Lissauer) are located. In this zone small spindle-shaped neurons are localized; they are also associative.
White matter C. of m — its conduction device — is made by back, side and front cords. Interiors of white matter, adjacent to gray, are formed by own bunches (front, lateral, back) S. in the m which are ascending and descending long and short intersegment bonds. It is the most ancient department of white matter. The periphery of cords is occupied with the bilateral ascending and descending ties between back and a brain (see. Conduction paths ).
S. of m carries out two main fiziol. functions: own (segmented) reflex activity (see. Reflex ) and the conduction function providing communication of a brain with the periphery (see. Conduction paths). Between these two functions there is complex relationship, to-rye the nadsegmentarny centers and formations of a brain of various function levels can characterize as subordination of segmented reflex activity of S. of m.
For the first time S.'s participation was established by m in reflex reactions at the end of 18 century in S. Hales, R. Whitt, Stewart's experiences (T. A. to Stewart) with S.'s destruction in m at frogs. Ch. Bell (1811) and F. Ma-zhandi (1822) independently from each other showed that back roots of spinal nerves transfer sensitive (centripetal), and lobbies — motive (centrifugal) signals (the law Bella — Marangdi). In 1850. The hall (M. of Hall) published a detailed research of reflex reactions back and a myelencephalon, in Krom for the first time used the term «reflex arc». An important stage of studying of functions C. of m frogs (Türk's reflex) had an opening in 1863 by I. M. Sechenov of the phenomenon of braking of a bending reflex of S. of m at chemical irritation mesencephalon (see).
Section and destruction of these or those its structures with the subsequent research of disturbances of reflex functions became classical methods of studying of functions C. of m. However possibilities of these methods are more limited, than at a research of a brain because in S. neurons of various functional accessory are not so accurately concentrated by m in limited spatial structures and, therefore, are hardly accessible for selective influence. Successful development of physiology of S. of m is connected with improvement of methods gistol. researches of its neural structure, and hl. obr. methods elektrofiziol. registration of total electric potentials of S. of m, and also electric reactions of separate neurons with the help out of - and intracellular microelectrodes (see. Microelectrode method of a research ). By means of these methods the structure and functions of interneural bonds of S. of m are revealed, cellular mechanisms of the main forms of its reflex activity are installed and functional characteristics of various types of neurons of S. of m are measured.
Motive nervous cells, or motor-neurons, are the output (efferent) cells of S. of m (see. Nervous cell) which are carrying out transfer of the m of signals to skeletal muscles developed in S. Together with the muscle fibers innervated by them each motor-neuron forms motive unit. Nerve fibrils of neurons of S. of m classify by the speed of carrying out excitement and thickness (diameter) on groups A, B, S. Tolstoy myelinized, quickly - the carrying-out fibers of group A subdivide into 4 subgroups — and, P, y, 6 (in decreasing order of the speed of carrying out an impulse). Axons of motor-neurons have high speed of carrying out an impulse of excitement and belong to fibers of group A and (see. Nerve fibrils). At excitement located on som and dendrites of motor-neuron of the synoptic terminations of afferent cells or interneyron (intermediate, inserted) in motor-neuron under the influence of the mediators allocated by the terminations (see) there is a local depolarization of membranes — the exciting postsynaptic potential (VPSP). At summation of V PSP to a critical level there is an action potential (AP), to-ry consists of several components differing on the speed of development (PD som and dendrites, PD of an initial segment of an axon). The maximum frequency of reproduction of PD in motor-neuron does not exceed 200 — 300 impulses in 1 sec. More often it significantly lower (several tens of impulses in 1 sec.) in connection with emergence after PD of long after hyperpolarization, amplitude a cut approximately in 10 times more, than amplitude of hyperpolarization in an axon. Existence of such hyperpolarization reduces the frequency of reproduction of an impulsation motor-neuron. On expressiveness of after hyperpolarization and frequency of an impulsation motor-neurons divide into two groups — on phasic and tonic motor-neurons, features of excitement to-rykh correlate with functional properties of the muscles innervated by them. More bystry «white» muscles are innervated respectively phasic, and slower «red» — tonic motor-neurons.
A specific place in the functional relation is held disseminated between and - motor-neurons small motor-neurons of S. of m (7 motor-neurons), axons to-rykh belong to nerve fibrils of group A. 7 Motor-neurons innervate intrafusal (intra spindle) muscle fibers. Reduction of intrafusal muscle fibers at excitement of 7 motor-neurons does not lead to emergence of the motive answer, however significantly increases the frequency of the afferent category going from stretch receptors of a muscle. A basis of braking of motor-neurons is emergence in them at the corresponding synoptic influences of local hyperpolarization of membranes — the braking postsynaptic potential (see Bioelectric potential) approximately the same duration as VPSP. The braking postsynaptic potentials (TPSP) are created not by directly afferent fibers, but the special interneyrona which are synthesizing and allocating the corresponding braking mediator, to-rogo play a role glycine (see) and piperidic acid (see).
Motor-neurons in S. are collected by m in groups (kernel) on a functional sign — an innervation of certain groups of muscles. At emergence of reflex motor reaction rather small amount of cells of a kernel (other cells remain in a condition of subthreshold excitement, forming «a subthreshold border») is excited, according to it only a part of motive units is activated (so-called fractionation of the motor field across Sherrington). At convergence to a motive kernel of two and more afferent waves local processes are summed up and involve bigger amount of motor-neurons therefore there is a so-called simplification of the reflex answer in the category. Ability to pass from a subthreshold state into a condition of activity is not identical at various motor-neurons. Cells of the bigger size have lower excitability, than smaller. At the braking influences opposite process takes place — the bigger quantity of motive nervous cells passes into a condition of subthreshold synaptic activation and thus the so-called «subthreshold border» increases.
An important link of the organization of functions of motor-neurons — existence of system of the negative feed-back (see) formed by aksonny collaterals and the special braking internuncial neurons — Rensho's cells. Cells to Rhenium can cover the returnable braking influences extensive groups not only motor--, but also interneyron. Thanks to this eurysynusic system of a negative feed-back motor kernels appear under brake control, not only the motor-neurons which were generating the category and put aksonny collaterals, but also the motor-neurons forming «a subthreshold border» in action are subject to Krom. As a result of action of such system motor kernels can effectively keep in a condition of the low activity sufficient for implementation of usual motive activity and keeping at the same time great reserve opportunities on a case of sharp increase in requirements to muscular activity.
The special group of efferent cells of S. of m is made by the neurons of the autonomic nervous system (see) localized in chest part C. of m. These are sympathetic neurons, axons to-rykh form preganglionic fibers. On functional properties they are divided into a number of groups. The basic group located in an intermediolateralny kernel has the axons relating to group B. Besides, in a limited dorsomedial zone of a front horn neurons with more quickly carrying-out axons are found, and cells with slowly carrying out axons are found in a lateral part of an intermediate zone (group C). Idiosyncrasy of functioning of sympathetic preganglionic neurons very low frequency of their tonic pulse activity is. For many neurons of a basic group communication with maintenance of a vascular tone is found. Cells of other groups of vegetative neurons provide regulation of other vegetative effector structures (ferruterous cells, smooth muscles went. - kish. path, skin). The irritation of afferent ways causes in sympathetic neurons of S. of m reflex categories with the considerable eclipse period that indicates activation them on polisinaptiche-sky, i.e. including several consecutive interneyron, to ways. Along with activation there can be also a braking of pulse activity. At a part of neurons also returnable braking similar on type to braking of motor-neurons is observed.
Parasympathetic neurons form sacral parasympathetic kernels, to-rye are located in lateral intermediate gray matter of sacral segments C. of m (S2 — S4). Many of them are in a condition of background pulse activity, increase in frequency a cut matches build-up of pressure in a bladder. At irritation visceral, napr, pelvic, or somatic esodic nerves of extremities in these cells there is a caused category differing in very big stage of latency. There are bases to assume existence of returnable collaterals at the parasympathetic neurons having the returnable braking effect on them through interneyrona, similar to Rensho's cells.
(Inserted or to interneyrona) carry those nervous cells to associative cells, axons to-rykh do not leave S. of m. Depending on the course of shoots they are divided on actually spinal and projective (the m connecting S. with various structures of a brain). Synoptic influences on interneyrona are also mediated through VPSP and TPSP, summation to-rykh at achievement of a critical level leads to emergence of the extending PD. Duration of PD in interneyrona is less, than in motor-neurons, and their generation is not followed by considerable after hyperpolarization. Therefore interneyrona can generate categories of impulses of more high frequency — to 500 and even 1000 in 1 sec. As a basis for functional differentiation of interneyron use features of their answers to the signals arriving on afferent fibers of various type. Interneyrona, connected synoptic with certain types of these fibers, are grouped in well outlined horizontal plates in dorsal and intermediate parts of gray matter C. of m. This functional topographical differentiation matches cytovery tectonic division of gray matter on Reksed's (fig. 5) plates. In the most dorsal sites of gray matter C. of m (a plate the I—III, forming jellylike substance, or gelatinous substance) neurons are located, axons to-rykh intertwine in a dense longitudinal bunch and, having passed in it a certain distance, sipaptichesk on other neurons of the same plates come to an end. These neurons synoptic are activated by high-threshold skin and muscle afferent fibers. More low-threshold afferent fibers from skin and muscles have the long braking effect on their activity. Such organization of functions of interneyron of these plates can provide tonic influences of jellylike substance on other spinal structures. Assume, in particular, participation of neurons of jellylike substance in the mechanism of creation of presynaptic braking. In the IV plate of gray matter the interneyrona which are initially connected with afferent fibers from tactile skin receptors (see) in the V plate — with high-threshold fibers of the receptors which are in skin and muscles (so-called offerers of a bending reflex) in the VI plate — with low-threshold afferent fibers from muscles are localized. The lamellar functional and morphological organization in more ventral sites of gray matter is broken. In VII and VIII plates find interneyrona with various characteristics of afferent entrances. In these plates also Rensho's cells receiving synoptic influences from aksonny collaterals of motor-neurons are located.
All listed functional groups of interneyron usually carry to segmented as their activity has in S. m limited distribution and involves in action of an interneyrona and motor-neurons of the next segments. Along with them in S. of m there are interneyrona, axons to-rykh pass through several segments or even from one department of S. of m in another. Such neurons are designated as intersegmental, or propriospi-nalny; their axons form own bunches of S. of m. Neurons, axons to-rykh pass up to five segments, form short own, propriospinalny bunches or ways; they are disseminated among other neurons of dorsal and intermediate areas of gray matter (lateral and back own bunches). Neurons, originative to the long descending and ascending propriospinalny ways (own bunches of S. of m connecting cervical and lumbar departments of S. of m), are localized preferential in a ventral part of gray matter (the IX plate), and their axons go in the forefront of a side cord and in a front cord (side and front own bunches).
Also cells shall be carried to interneyrona, axons to-rykh create the ascending ways which are projected in various structures of a brain (see). Axons of these neurons leave gray matter in cords of white matter where are grouped to the respective highways: dorsal — back and ventral — front back and cerebellar, spinobulbarny (spinoretikulyarny, T.), spinotalamicheskiya, etc.; bodies of neurons are localized in various plates. Neurons of various ascending ways differ on features of synoptic activation from peripheral afferent fibers.
Spinal interneyrona are functionally divided also as their synoptic bonds with the long descending ways transmitting to S. m signals from various structures of a brain. Interneyrona, directly connected with cortical and spinal (pyramidal) ways, the interneyrona connected with krasnoyaderno-spinal fibers — in the same area, but a little ventralny — in the VI—VII plates are localized in the most lateral sites V—VI of plates, and. Interneyrona, connected with fibers of preddverno-spinal and retikulyarnospinnomozgovy ways, are localized in medial sites VII—VIII of plates of gray matter C. of m
Thus, all mass of interneyron of S. of m can be divided into a number of functional groups, each of to-rykh takes part in implementation of a certain type of the reflex activity determined by signals from the corresponding peripheral receptor systems and (or) «commands» from various structures of a brain. At the same time extensive convergence of the exciting and braking synoptic influences of interneyron of one type on interneyrona of other types forms a basis of interaction of such functional groups in case of their simultaneous activation. Therefore systems of spinal interneyron define specifics of effector activity of S. of m, activating motive kernels, necessary for its performance, software the principle of the general final motive way.
Microelectrode researches showed that in S. of m there is a large number of interneyron, on to-rykh there is an interaction of somatic and visceral afferent signals; interneyrona are located on the most part of gray matter. Nek-rye from cells is answered on somatic, others better — visceral signals. However interneyron, to-rye would be accurately specialized on transfer only of visceral afferent influences to vegetative efferent neurons, it is not revealed.
The volume of functions, to-ry can carry out S. of m, considerably depends on whether bonds of spinal structures with structures of a brain remain. So, at the decerebrated animal (see Decerebration) it is possible to observe (though in the distorted form) irregular shapes of the activity created by S. in m; after S.'s section of m (spinalization) this shape of activity is got out of. The reason of such action of a spinalization is double. On the one hand, S.'s dissociation m with overlying structures breaks off the reflex arcs responsible for implementation of the corresponding reaction passing through certain supraspinal structures. Treat such disturbances loss of periodic categories of motor-neurons of the respiratory muscles providing the respiratory movements, and loss of tonic categories of sympathetic neurons of S. of the m supporting a vascular tone and according to the ABP. On the other hand, after dissociation head and S. of m the functional condition of spinal neural systems in connection with loss of tonic influences of the structures of a brain necessary for normal functioning of neurons of S. of m changes. The termination of difficult rhythmic locomotory acts belongs to such disturbances, e.g., (pacing, etc.); they disappear after a spinalization, but can be recovered at introduction to an animal of the substances stimulating allocation of mediators with the synoptic terminations of the cut descending ways. In the general form of disturbance of functions C. of m after department it from a brain is designated the term «spinal shock»; expressiveness of its subjects is more considerable, than nervous activity of an organism is organized more difficult.
Allocate several forms of reflex reactions, to-rye can be provided with neural structures of S. of m entirely. Myotatic contractions (myotatic reflexes) are the only reflexes of S. of m, at to-rykh management of motor-neurons by means of the signals arriving from afferent fibers of muscle spindles takes place direct (without participation of interneyron). These reflexes are shown by reflex shortening (increase in tension) of a muscle in response to its stretching (see. Tendon jerks ). They differ in locality and lack of an essential after-effect. Are most expressed in razgibatel — muscles, to-rye shall be in a condition of tonic tension in order that the organism could resist to force of terrestrial gravitation. Reflexes are always accompanied by braking of antagonistic muscles due to activation by collaterals of afferent fibers of group of the braking interneyron. The group of the synergy and antagonistic muscles combined functionally by system of myotatic contraction is designated as myotatic unit; such units are included in more irregular shapes of motive activity — maintenance of a pose, etc. The irritation of receptors of the motive device gives rise also to some other less expressed motor reactions (reaction of lengthening, crossed reflex of stretching, a bending reflex of stretching) having polisinaptichesky character (i.e. carried out by means of interneyron).
Bending reflexes consist in bystry reduction of flexor muscles and an otdergivaniya of an extremity; at strong irritations are followed by cross extensive effect, and also pressor vascular reaction. There are they at irritation of the skin receptors capable to voprinimat various characteristics of mechanical and temperature irritations, and have protective character. Unlike myotatic bending reflexes are widespread and take at strong irritations not only muscles of extremities, but also muscles of a trunk; they differ also in the temporary characteristics — cannot be reproduced with high frequency (reflexes of ryvkovy type). The last feature is connected with emergence in the central structures after synchronous activation of quite long period of a depression.
One of mechanisms of its emergence is the depolarization of the central bombways of the corresponding afferent fibers leading to presynaptic braking of synoptic transfer of the signals arriving on them. Bending reflexes considerably amplify after S.'s section of m that indicates existence of continuous braking them from a brain.
Rhythmic reflexes are expressed in the correct alternation of the muscular contractions, opposite on functional value, which are imposed on tonic contraction of certain muscles. The mechanism causing such alternation of activity of various motive kernels (e.g., during the walking, etc.), is localized in the interneyronny device C. of m, however its activation requires receipt from motoriums of a brain of the tonic descending signal.
Visceromotor reflexes consist in emergence of motor reactions at excitement of visceral afferent systems. Reactions cover generally neurons, the innervating muscles of a chest and abdominal wall, and also a part of the neurons innervating extensor muscles of a back. As well as bending reflexes, they amplify after S.'s section of m in a cervical part and also have protective character; this similarity is based on extensive convergence of visceral and somatic afferent influences to the same interneyrona of S. of m. At the same time visceromotor reflexes have more expressed tonic character that indicates their specificity.
Spinal vegetative reflexes (see), despite their sharp oppression after a spinalization, are shown in limited volume that indicates a possibility of their implementation at the expense of neural structures of S. of m. They consist in emergence of polisinaptichesky categories of sympathetic neurons of S. of m in response to excitement of visceral afferent fibers, and also the somatic afferent fibers causing a bending reflex and cause emergence of pressor vascular reaction.
Also reflex reactions of parasympathetic neurons in response to irritation of afferent fibers of splanchnic (celiac) nerves are possible. They represent a basis of an imperfect urethral reflex, to-ry is observed at animals and the person later a long time after section or S.'s damage by m. These reactions are caused by irritation not only visceral, but also somatic receptors. Along with performance of own reflex reactions spinal neural structures are executive office for a huge number of the reactions of varying complexity which are carried out through structures of a brain. The descending ways of a brain can be directly connected with motor-neurons and exercise direct control of the last or management by means of system of spinal interneyron. Direct control of motor-neurons of S. of m is exercised, on the one hand, of motor area of a cerebral cortex (see) through the nek-ry cortical and spinal (pyramidal) neurons forming with them direct (monosinaptichesky) bonding. Such neurons at the person make apprx. 8% of all structure of pyramidal neurons, and at subprimacies they in general are absent. Monosinaptichesky connection provides generally performance of thin autokinesias of distal departments of extremities. On the other hand, direct synoptic bonding with motor-neurons has predoor and reticular and spinal ways. These connections are well developed at all vertebrate animals, and preddverno-spinal ways go preferential to motor-neurons of extensor muscles, and reticular and spinal — to motor-neurons of flexor muscles. In cervical part C. of m quite often there is a convergence of various descending influences to the same motor-neurons. Experimental switching off of preddverno-medullispinal ways causes decrease in a reflex tone of extensive muscles due to loss of the tonic facilitating influences from a vestibular nucleus on the corresponding motor-neurons. Similar tonic influences from a reticular formation regulate reflex activity of preferential flexion muscles.
Along with direct influences on motor-neurons all descending systems carry out transfer of suprasegmentarny signals to motor-neurons through spinal interneyrona, first of all, through systems of the neurons forming short intersegmental bonds. Functional properties of the last and features of their bonds with the descending fibers and the subsequent neurons create ability to integrate the signals arriving on various descending ways and also their certain processing and space redistribution.
Treatment morfol. the changes developing in S. of m it is accompanied by the difficulties caused by anatomic communication of S. of m with a brain and a peripheral nervous system. Therefore many patol. the processes developing in the last cause changes and in S. of m. Especially often it is observed at disturbances of cerebral circulation (e.g., a secondary degeneration of myelin fibers C. of m at strokes), encephalitis, polyneuropathies (retrograde degeneration of neurons of S. of m) and other diseases. Row patol. S.'s changes the m is caused by alimentary factors and hypovitaminoses, e.g. a funicular myelosis (see), retrograde, or pellagroidny, a degeneration of neurons of front horns of S. of m at a vitamin deficiency of group B, and also metabolic disturbances, malignant tumors of internals (paraneo-plastic myelipathies at cancer of a lung, mammary gland, large intestine and other bodies), impact of ionizing radiation at radiation therapy of tumors of nek-ry localizations. It is especially difficult to interpret such nonspecific changes as demyelination, a retrograde and transsinaptichesky degeneration of neurons, axonal dystrophy, to-rye often there are in S. m at various diseases.
Dystrophic changes in S. of m are observed in neurons, a neuroglia, nerve fibrils, vessels and covers. In literature the term «dystrophy» it is accepted to designate (though it is not absolutely justified) also separate types of changes of neurons, characteristic of nek-ry diseases, and a neuroglia, napr, lipopigmentny dystrophy, argyrophil dystrophy of neurons at Alzheimer's disease (see. Alzheimer disease ), gliozny dystrophy at metabolic disturbances and at persistent hypostasis of tissue of brain, neurotoxic spongy dystrophy at Kreytifeldt's disease — Jacoba (see. Kreyttsfeldta — Jacoba a disease ), gliovazalny dystrophy at Wilson's disease — Konovalova (see. Hepatocerebral dystrophy ). The term «dystrophy» is used also in names nek-ry nevrol. diseases; napr, hepatocerebral dystrophy, spongy dystrophy, leukodystrophy.
to the Necrosis (see) separate neurons and their groups, cells of a neuroglia, fiber of white matter, vessels, covers and the whole sites C. of m, sometimes on a considerable extent can be exposed.
Distinguish the full and incomplete necrosis of gray and white matter C. of m developing at his ischemia, inflammatory processes, influence of the damaging ionizing radiation doses. S.'s changes the m caused hron. ischemia, call also vascular myelipathy, a cut the changes of vessels observed at atherosclerosis, arterial hypertension, vasculites, malformations of vascular system C. of m, a diskosis, a compression of vessels by a tuberculoma, a gumma, a tumor are the cornerstone. S.'s necroses of m develop also at a thrombembolia, an embolism atheromatous masses from the breaking-up atherosclerotic plaques of an aorta, and also in rare instances at Ekhmboliya of vessels fragments of fabric of an intervertebral disk.
For a full necrosis, to-ry has signs kollikvatsionny and only sometimes coagulative, death of all elements of a brain is characteristic. In process of the organization (see) the center of a full necrosis the gliomezodermalny hem sometimes containing a cavity (cyst) forms. Death of neurons or nerve fibrils with formation of the centers of devastation, an isomorphic or anizomorfny gliosis is characteristic of an incomplete necrosis (an elective, selective necrosis of a parenchyma of a brain) (see).
Disturbances of blood circulation in S. are more often shown by m in shape ischemia (see), hemorrhages are less often observed (see). Morfol. the changes caused by ischemia are localized in certain zones of segments C. of m. A selective necrosis of the central departments of front horns, the bases of back horns and the central intermediate (gray) substance consider as an effect of ischemia of S. of m of easy degree. Heavier changes — the symmetric centers of a necrosis in front horns and in the basis back or a necrosis of all gray matter of several segments C. of m — are observed during the falling of the system ABP and anoxic states. The heart attacks (is frequent with a hemorrhagic component) occupying all diameter of S. of m or its part (fig. 6) develop at pathology of an aorta, one or several radikulomedullyarny arteries. Patol. the centers of vascular genesis are localized most often in chest segments C. of m, is more rare in lumbar and other segments. Centers of a necrosis (S.'s heart attacks of m) have the form of a spindle or the column penetrating front horns of several segments. At disturbance of blood circulation in S.'s veins of m there come hypostasis and hemorrhagic treatment of white matter.
A special form of vascular pathology of S. of m connected with disturbances of microcirculation are its changes at the so-called isolated death of a brain (see. Death of a brain ).
Intramedullary hemorrhages (hematomyelia) are localized preferential in the field of back cords. In most cases they are observed at malformations of vessels of S. of m (vascular malfor-mation), tumors, abscesses, metastasises of tumors of other bodies, a myelosyringosis. Small perivascular hemorrhages in S. of m arise also at arterial hypertension. On their place a long time the macrophages containing hemosiderin remain.
Subarachnoidal hemorrhages can result from a rupture of aneurisms of spinal vessels.
Patol. changes in S. of m find at amiotrofiya (hereditary spinal and neural), an amyotrophic side sclerosis, spinotserebellyarny and olivopontotserebellyarny degenerations, and also at poliomyelitis of pi poliomiyelitopodobny diseases, encephalomyelitis (herpetic, arboviral, tick-borne, horse, postvaccinal), the Japanese encephalitis, leukoencephalites, multiple sclerosis, metastatic purulent encephalomyelitis, S.'s abscess of m.
At a meningeal tuberculosis of granulomas in an arachnoid membrane of a spinal cord it is much less, than in the same cover of a brain (see Tuberculosis vnelegoch-ny). Quite often inflammatory process passes to roots of spinal nerves, and also to fabric C. of m (a peripheral regional myelitis) and to vessels that leads to disturbances of blood supply of S. of m Nek-ry researchers carry a tubercular myelitis to rare diseases and consider characteristic in it morfol. to a picture existence of perivascular accumulations of lymphocytes, ring-shaped groups of eiitelioidny cells with lymphocytes around them and small granulomas in walls of intramedullary vessels. As a result of distribution of process with web on a firm cover the spinal pachymeningitis develops (see). At the same time on an inner surface of a cover granulomas and big mass of granulyatsionny fabric (a hypertrophic pachymeningitis) squeezing S. m, vessels and roots of spinal nerves are found. In S. of m tuberculomas of gray matter with a diameter of 1 — 10 mm meet.
At syphilis (see) the most frequent forms of defeat of S. of m are a meningomyelitis and back tabes (see). S.'s gummas of m (a gummous syphilitic meningomyelitis) meet seldom. They proceed from a firm meninx, 10 mm have a diameter, the m and its vessels can squeeze S. The m leads commissural process between covers, vessels and S. to a prelum of roots of spinal nerves and disintegration of their fibers (a syphilitic meningoradiculitis).
S.'s mycoses of m and its covers are observed seldom. They develop, as a rule, as a result of distribution patol. process of a brain and at generalization of a mycotic infection. Separate cases of aspergillosis meningitis of S. of m after a spinal puncture and mukorozny meningitis after spinal anesthesia are described.
S.'s regeneration m is imperfect; recovery of the main carrying-out systems does not happen.
METHODS of INSPECTION
Major importance in diagnosis of diseases of S. of m belongs nevrol. to the inspection of the patient (see) directed to establishment topics of defeat of S. of m. Comparison of symptoms of local segmented defeat of S. of m to prevalence of conduction motive and sensitive disturbances, the nature of change of functions of pelvic bodies usually allows to establish rather precisely localization patol. the center and its volume (see below). However for specification topics of process, relationship patol. the center with surrounding fabrics, character patol. process (inflammatory, tumoral, vascular, etc.), solutions of a question of degree of operability, etc. there is a need for carrying out additional researches. Important information is obtained at a research of cerebrospinal liquid. During a spinal or suboktsipitalny puncture estimate passability of a subarachnoid space (see. Liquorodynamic tests , Spinal puncture , Suboktsipitaljnaya puncture ), and then subject a lab. to a research the received cerebrospinal liquid (see).
Localization of defeat, and also a functional condition of structures of S. of m are defined by a row elektrofiziol. methods — an elektroneyromiografiya and an electromyography (see), electrodiagnoses (see), elektromiyelografiya, registration of the caused electric potentials of S. of m.
In diagnosis of various processes in S. m use thermovision (see Termografiya) and a computer tomography (see the Tomography computer). Anatomic contours of the vertebral channel and S. of m can be visualized by means of various methods rentgenol. and radio-isotope research.
Methods rentgenol. researches allow to reveal as the damages of a backbone causing S.'s compression of m, and various processes in the vertebral channel, covers, vessels and fabric C. of m. In addition to an obligatory X-ray analysis of a backbone (spondilografiya), use a tomography (see), edges gives the chance to detail and more precisely to estimate structural changes of vertebrae, the sizes of the vertebral channel, to find kal-tsinata, etc. If rentgeno-and a tomography do not allow to receive rather full diagnostic data, resort to X-ray contrast researches — miye-lografiya (see) and (or) pnevmomiyelografiya (see), helping with topical diagnosis (cm) levels and the extent of a compression, malformations of S. of m, etc. By high-informative methods rentgenol. a contrast research are a spinal angiography (see) and the venospondilografiya, with the help to-rykh became possible diagnosis of spinal arteriovenous aneurisms (vascular malformation) of S. of m, identification of the reasons of ischemic defeats of S. of m. Combination of various methods rentgenol. researches plays a crucial role in diagnosis of tumors of S. of m.
The radio isotope (radionuclide) miyelografiya is carried out by the patient with symptoms of a compression of S. of m of various origin (damage of vertebras and intervertebral disks, parasitic diseases, S.'s tumors of m and its covers, arachnoidites, etc.). S.'s prelum of m is combined with the narrowing or the full block (impassability) of a subarachnoid space causing disturbance of circulation of cerebrospinal liquid. In these conditions introduction to a subarachnoid space of the radiofarma-tsevtichesky drugs (RFP) which are mixing up with cerebrospinal liquid allows to estimate degree of passability of a subarachnoid space and to determine levels of an obstacle. For a radionuclide miyelografiya use liquid RFP (mIn — DTPA, 99 t of the CU - DTPA) and radioactive gases (see Radiofarmatsevtichesky drugs). After endolumbar introduction of RFP carry out radiometry by means of odnodatchikovy scintillation installation, the scanner or the gamma camera (see. Stsintigrafiya ).
When passability of a subarachnoid space is not broken, the registered activity of RFP on all longitudinal axis of a backbone is approximately identical and is noted also over area of the big tank (the cerebellar and brain tank, T.) brain. At the full block of a subarachnoid space activity of RFP comes to light only to the lower bound of an obstacle. At the incomplete block at the obstacle narrowing a subarachnoid space of S. of m only a part of the entered RFP (increase in radioactivity is registered here) is late, and its other portion goes to overlying departments of a subarachnoid space of S. of m, turning on also the big tank of a brain.
At S.'s tumors of m this method of a research allows more than in 95% of cases to obtain exact data on the level of an arrangement of a new growth and extent of disturbance of circulation of cerebrospinal liquid. Results of a radionuclide miyelografiya at inflammatory diseases of covers of S. of m have smaller value, but sometimes the delay of RFP at various levels demonstrates existence of commissural process. Comparison of kliniko-neurologic data with results of a radio isotope research gives the chance to establish localization and extent of process at patients with a widespread spinal arachnoiditis. The radionuclide miyelografiya helps with topical diagnosis of parasitic and other opukholepodobny processes in S. to m
S.'s Pathology of m is diverse that has a talk, on the one hand, its close anatomic and functional linkages with a brain, peripheral and the autonomic nervous system, on the other hand — involvement of structures of S. of m in various (metabolic, neurochemical, immunopato l ogicheek not, etc.) the processes happening in an organism of the patient. The standard classification of defeats of S. of m does not exist. Conditionally allocate malformations, damages, various diseases and tumors.
S.'s damages of m are caused by disorders of functions of its segmented and conduction device. Segmented disturbances arise at defeat of gray matter C. of m, back (sensitive) and ventral (motive) roots. Defeat of the segmented device is shown by motive, sensitive, reflex, vascular, secretory and trophic frustration. At defeat of a back root there are shooting, girdle pains, then decrease or loss of all types of sensitivity (see) in the corresponding dermatome. There can be an easing or loss of reflexes (see), the arch to-rykh passes through the struck root. At defeat of a back horn of pain, as a rule, do not arise, disturbances of sensitivity have the dissociated character (loss painful and a thermoesthesia at preservation tactile and muscular and joint feeling), reflexes also decrease or disappear. The similar dissociated disorder of sensitivity on segmented type, but bilateral symmetric arises at destruction of front gray commissure of S. of m. At defeat of a front horn and root paresis or sluggish paralysis with an atrophy and an atony of muscles of the corresponding myotomes with loss of certain deep reflexes develops. At early stages of perednerogovy defeat in muscles fibrillar and fascicular twitchings are observed. At segmented defeat of cells of a side horn there are vegetovascular, trophic disorders, disturbances of sweating, shtlomo-even reaction, reflex functions of pelvic bodies (see the Autonomic nervous system).
Conduction disturbances arise at defeat of conduction paths of S. of m; unlike segmented they have more widespread character. Nair., at defeat of motive (pyramidal) ways is able the central (spastic) paralysis (see Paralyses, paresis; Conduction paths) there are all muscles innervated from all underlying segments; at a break of sensitive ways there comes the anesthesia from top to bottom from the level of defeat covering zones of an innervation of the segments C. located below of all m. Conduction disturbances at destruction of a back cord are shown on the party of the center by disorder of muscular and joint, tactile and vibration sensitivity (see), development of a sensitive ataxy (see). At defeat of a side cord on the party patol. the center lower than the level of defeat there is the central paralysis, and on the opposite side of a body — painful and temperature anesthesia (see).
At patol. processes in S. the m needs to establish their localization in relation to segments, horns and kernels of gray matter, cords and bunches of white matter, the central channel, vessels, roots of spinal nerves, S.'s covers of m and the vertebral channel. An important component the wedge, the diagnosis at S.'s pathology of m is definition of localization and prevalence patol. the center in the cross and longitudinal directions, i.e. topical diagnosis of defeats of S. of m. The main symptom complexes of defeat of S. of m at various levels is the following. 1. Defeat of all diameter of S. of m in verkhnesheyny department (C^v segments) is shown by sluggish paralysis of muscles of a neck, a phrenoplegia, a spastic tetraplegia, anesthesia in a neck and a nape, the general anesthesia of a trunk and extremities, dysfunction of pelvic bodies for the central type (a delay and a periodic incontience of urine and a calla); quite often there are radicular neck pains giving to a nape. 2. Defeat at the level of a cervical thickening leads (Cv — Thx segments) to sluggish paralysis of hands with an atrophy of their muscles, loss of reflexes on hands, to spastic paralysis of legs, the general anesthesia there is lower than the level of defeat, to dysfunctions of pelvic bodies for the central type. Defeat of cells of a side horn at the level of CVI „— Thx causes Bernard's syndrome — Horner (see Bernard — Horner a syndrome). 3. Defeat of diameter of S. of m at the level of chest segments leads to the lower spastic paraplegia, conduction general anesthesia in a lower body, the upper bound a cut corresponds to the level of the struck segments, an ischuria and a calla. At destruction of upper and average chest segments (Thn_VI) function of mezhreberyy muscles is broken (paralysis) that causes difficulty of breath; defeat of Thx_xn segments leads to paralysis of muscles of a prelum abdominale; involvement in process of considerable number of segments of chest department causes atrophic paralysis of muscles of a back. Radicular pains at the same time have the surrounding character. 4. Damage at the level of a lumbosacral thickening (Lj — Sn segments) is caused sluggish paralysis of the lower extremities, anesthesia of the lower extremities, disturbance of sweating and pilomotor reaction only standing, by the disorder of functions of pelvic bodies which is shown an ischuria and a calla. 5. The syndrome of an epikonus (segments LIV — S „) described by L. S. A minor, includes sluggish paralysis of the muscles innervated by a sacriplex (with preferential damage of a fibular muscle and relative safety of tibial muscles), disappearance of Achilles reflexes (see) at safety knee, anesthesia in a zone of the struck segments, a delay or an incontience of urine. 6. Defeat of a cone of S. of m (Sm segments — Cells) is characterized by disturbances of functions of pelvic bodies for peripheral type with a true incontience of urine and a calla, lack of desires to an urination and defecation, anesthesia (sometimes the dissociated disturbances) in an anogenitalny zone (saddle anesthesia), impotence (see). At the same time paralyzes of extremities and pain are absent.
At destruction patol. process not of all diameter of S. of m but only its parts a wedge, the picture consists of various combinations of disturbances of movements, coordination, superficial and deep sensitivity, disorders of function of pelvic bodies and a trophicity in the struck zone (decubituses, etc.). Most often the following options of incomplete defeat of diameter of S. of m meet: 1) the defeat of a front (ventral) half of diameter of S. of m which is characterized by a flaccid paralysis of the muscles derivative of a myotome of appropriate level the central paralysis of muscles both conduction painful and temperature anesthesia is lower than the level patol. center, dysfunction of pelvic bodies for the central type; 2) the defeat of one half of diameter of S. of m (right or left) which is clinically shown Broun-Sekar's syndrome to-ry includes the central paralysis, emergence of a strip of segmented anesthesia and decrease in joint muscle sense on the party of the center and conduction loss of superficial sensitivity on the party opposite to the center (from level is 2 — 3 segments lower than the center of defeat); 3) the defeat of a back third of diameter of S. of m which is shown disturbance of deep sensitivity, a sensitive ataxy.
In diagnosis of defeats of S. of m the sequence and rate of development nevrol is of great importance. symptom complex. E.g., at the acute traumatic, vascular and infectious processes which are suddenly striking S.'s diameter of m in cervical or chest departments atonic paralysis with anesthesia on conduction type with simultaneous lack of deep and cutaneous reflexes, disturbance of functions of pelvic bodies, hypostasis of hypodermic cellulose, quickly arising decubituses develops (see Bastian the law). The syndrome of spinal automatism with protective reflexes is characteristic of slowly developing defeats (e.g., of tumors) these departments of S. of m (see). The sequence of development of symptoms allows to differentiate sometimes primary (intramedullary) defeat of S. of m from the secondary (extramedullary), tied with pathology backbone, covers, vessels, etc. E.g., at ekstrakhmedul-lyarny processes by one of the first a wedge, signs the radicular pains and disturbances of sensitivity which are consistently accruing from below up are; at intramedullary processes radicular pains are absent in the beginning, disorders of sensitivity develop on the descending type. This distinction in the sequence of emergence of dysfunctions is explained by an arrangement of conduction paths, excentric in relation to gray matter C. of the m, innervating distal departments of extremities.
At nek-ry defeats of back cords at the level of cervical department of S. of m (at an extra-and intramedullary tumor, multiple sclerosis, a spondilogenny miyeloishemiya, an injury) at the time of a ducking of a kpereda there is sudden pain penetrating all body, similar to blow by electric current (Lermitt's symptom). At topical diagnosis of defeats of S. of m it must be kept in mind discrepancy of level of segments C. of m to level of vertebrae, identical on the account. The Nek-ry receptions allowing to establish the level of an arrangement of a tumor — see below in the section «Tumours».
the dysgenesis or an underdevelopment of an ectoderm and a mesoderm resulting in anomalies of development of a backbone and c is the cornerstone of malformations of S. of m. N of page. The pathogeny of malformations of S. of m is difficult. In addition to hereditary factors, influence on a germ or on a fruit during the earliest periods of its development of infections, intoxications, injuries, endocrine and exchange disturbances is of great importance for their formation. The damaging influences lead to disturbances of an embryogenesis and the wrong short circuit of a neurotubule, and then to a nesmykaniye, splitting (macaw-fii) of a back seam throughout the forming S. m. S.'s splitting can be followed by m not - fusion, splitting of bodies and arches of the vertebrae and fabrics located in and out of the vertebral channel. Most often malformations of S. of m are localized in its trailer part (sacral and lumbar segments), in a cut most late there occurs short circuit of a neurotubule. Malformations of S. of m usually happen multiple and also skulls are often combined with anomalies of development of a brain (see) (see). Severity of a malformation of S. of m can be various — from S., heavy with almost total absence, m to lungs, insignificant, the expressed dysfunctions which are not causing after the birth. However under the influence of the secondary reasons of exogenous and endogenous character the last create a basis for emergence of disturbances during later periods of life.
One of heavy displays of an agenesia or aplasia of c. the N of page is an amiyeliya, or S.'s absence of m. Completely S. is not at this malformation of m or on its place there are sites of incorrectly created nervous tissue which is not finding looking alike a normal structure of S. of m of Amiyeliya quite often is followed by not fusion of the vertebral channel and soft tissues over it. The fruit with such malformation is usually impractical, and newborns with an amiyeliya soon perish. Amiyeliya is often combined with an anencephalia, an acrania or other malformations of a brain and skull.
The underdevelopment of any site C. of m, is more often than sacral department — an atelomyelia (myelodisplasia), can be followed by splitting of the relevant department of a backbone. It is clinically shown by dysfunction of sacral segments C. of m (an incontience of urine, lack of deep reflexes, in particular Achilles, disorder of sensitivity in a crotch, impotence, etc.). The atelomyelia of sacral part C. of m is quite often combined with hidden or clinically explicit spina bifida (see), flat-footedness (see), a clubfoot (See).
At a micromyelia cross sectional dimension of S. of m and quantity of nervous cells in front and back horns are reduced, there are no nek-ry conduction paths. The micromyelia is shown by an underdevelopment of extremities and paresis of muscles on peripheral type. At a diplomiyeliya (doubling, duplication, S.'s heterotopy of m) two S. of the m divided by connective tissue membranes, but having the general meninx can be created. In some cases the incomplete diplomiyeliya does not give any a wedge, manifestations.
The diastematomyelia (Greek diastema, diastematos an interval + myelos a brain) is a malformation of S. of m, at Krom is absent smykany its half on certain sites less often — on all its length. The diastematomyelia quite often is followed by not fusion of a backbone and the spinal hernia containing S. of m and its covers (myelomeningocele). It can clinically proceed as S.'s tumor of m with paresis or paralyzes, disturbance of sensitivity and function of pelvic bodies. Newborns with the listed malformations of S. of m perish soon after the birth. Are impractical also newborn with a difficult malformation — rakhiskhizisy — simultaneous not fusion of S. of m, a backbone and soft tissues of a back (see the Backbone, Spina bifida).
Special form of malformations of S. of m are spinal hernias — protrusion of covers, roots of spinal nerves and S. of m in the field of not fusion of a backbone with incomplete closing of the vertebral channel. They are quite often combined with other malformations, in particular a brain. Spinal hernias occur approximately at one of 1000 — 3000 newborns and are localized more often in lumbosacral area (fig. 7). Depending on contents of a hernial bag distinguish to a meningocele, a meningoradikulotsela, a myelomeningocele and a myelocystocele. The most often found form of spinal hernias is the myelomeningocele, the most rare — a myelocystocele. The protrusion only S.'s covers of m filled with cerebrospinal liquid is called by meningoceles (fig. 8, a). At S.'s meningocele of m it is not changed. Meningoradikulotsele is characterized by loss in a hernial bag of the myelinized roots of the spinal nerves which are usually spliced with a wall of a hernial bag (fig. 8,6) thinned insufficiently. At a myelomeningocele, in addition to covers and the changed roots of spinal nerves, the spinal cord is stuck out (fig. 8, c). The last is quite often spliced with walls of a hernial bag; in it such changes as a degeneration and insufficient quantity of nervous cells up to their total absence are observed, a gliosis, etc. At a myelocystocele the central channel C. of m is expanded and filled with cerebrospinal liquid, S. is stuck out by m together with covers through inborn defect in a backbone (fig. 8, d).
At all forms of spinal hernias the firm meninx is split and it is found only in the basis of protrusion. Soft and web covers take part in formation of a wall of a hernial bag, to-rye are usually spliced and are exposed to cicatricial changes. The cavity of a hernial bag at all forms of spinal hernias is filled with cerebrospinal liquid and is, as a rule, reported with a subarachnoid space of S. of m. Apply a gernio-grafiya, an endogernioskopiya, ultrasonic investigation to definition of contents of a hernial bag and the solution of a question of a form of spinal hernia.
Adequate treatment of the majority of malformations of S. of m does not exist. At a part of spinal hernias make neurosurgical operations. Indications to an operative measure are existence of a hernial bag and nevrol. disturbances. Urgent operative measure is shown irrespective of age of the child at sharp thinning of walls and bystry increase in the sizes of a hernial bag with threat of its gap, tendency to an ulceration, a rupture of a hernial bag with emergence of a liquorrhea. In the absence of urgent indications terms of carrying out operation define individually. Many neurosurgeons consider necessary to operate the child with spinal hernia in the first weeks and months of life. Others recommend to operate all children who were born viable with spinal hernias in the first 24 — 48 hours that does not lead to increase in a postoperative lethality.
Operation is contraindicated in the presence of other heavy malformations of S. of the m and internals expressed nevrol. frustration, inflammation of a hernial bag, meningitis, craniocereberal hernia or hydrocephaly. At malformations of S. of the m which are followed by the progressing hydrocephaly it is necessary to carry out its treatment in the beginning (see Hydrocephaly).
Operation, to-ruyu carry out under an endotracheal anesthesia or local anesthesia, consists a hernial bag with the subsequent muscular and fascial plastics of bone defect of a backbone (fig. 9) at a distance. To the child who is in a ventral decubitus, a circular (oval) section cut skin at the basis of hernia, allocate the basis and a leg of a hernial bag from soft tissues, and then open it. In the presence in a hernial bag of S. of m of roots of spinal nerves they are carefully separated from an internal wall of a bag and immersed in the vertebral canal. The hernial bag is excised with leaving of two rags, to-rye sewed over S. in m and roots of spinal nerves. At a narrow leg of a hernial bag it is tied up and the hernial bag is cut. Do not excise a hernial bag at a myelocystocele.
The correct maintaining patients in the postoperative period with appointment antiinflammatory, dehydrating and antipyretics allows to lower a possibility of development of complications considerably. Results of operational treatment it is much better at patients with a meningocele, than at patients with miyelomeningo-and to the meningoradikulotsela. For recovery broken nevrol. functions apply mud cure, to lay down. gymnastics, massage, etc.
The forecast at spinal hernia is always serious. About a half of children with malformations of a backbone and S. of m perish in the first weeks, from 80 to 90% — within the first year of life as a result of trophic disturbances, the accruing hydrocephaly and the meningitis developing owing to perforation of a hernial bag with a liquorrhea (see). The operational treatment which is carried out to the next few hours and weeks after the birth prevents development of complications and promotes the best recovery of functions C. of m. The postoperative lethality makes 7 — 10%.
See also Spina bifida .
Injuries of a spinal cord arise both in military, and in peace time. Functions C. of m at the same time are broken depending on degree of its concussion, frustration of a spinal hemodynamics, a compression by fragments of vertebrae or the dropped-out fragments of an intervertebral disk, etc. (see. Broun-Sekara syndrome , Hematomyelia , Vertebral and spinal injury ).
The operational treatment which is carried out in the acute period of an injury shall provide: recovery of normal relationship between a backbone, a spinal cord, a meninx and roots of spinal nerves; removal of the bone fragments which were implemented into a cavity of the vertebral channel, scraps of sheaves, blood clots; recovery of circulation of cerebrospinal liquid on a subarachnoid space of S. of m; reduction of vascular frustration; elimination of irritation and S.'s prelum of m at the level of damage; carrying out stabilization and, according to indications, fixing of a backbone.
Infectious (inflammatory) diseases of S. of m can be caused by various activators — viruses (see. Poliomyelitis ), bacteria, including mycobacteria of tuberculosis and leprosy, a pale treponema, etc. (see. Myelitis ). The inflammatory defeats of S. of m which are complications of such diseases as a brucellosis, shingles, pneumonia, measles, epidemic parotitis, chicken pox, etc. are possible. S. is frequent the m is involved in patol. process at meningitis (see), encephalitis (see. Encephalitis ), to a miyelopoliradikulonevrita (see), etc. S. the m is surprised also at such demyelinating diseases of presumably virus etiology as an amyotrophic side sclerosis (see) and multiple sclerosis (see). Special forms of inflammatory defeats of S. of m are back tabes (see) and tuberculosis of a spinal cord. Inflammatory process can develop in S. of m for the second time at distribution it from surrounding structures at an epidurita, a spondylitis, etc.
Abscess of a spinal cord and its covers meets seldom. Distinguish epidural, subdural and intramedullary abscesses.
Epidural abscess (purulent epidurit, a peripachymeningitis) arises owing to a drift in epidural cellulose in the hematogenous or lymphogenous way of contagiums from primary suppurative focus (e.g., a furuncle, an anthrax, etc.) or on contact from a nearby suppurative focus (e.g., at osteomyelitis of a backbone). More often epidural abscess is localized in chest part C. of m. In a wedge, a picture of acute epidural abscess the high temperature, a fever, severe radicular pains which are sharply amplifying at cough, sneezing, percussion or pressing on acanthas of vertebrae and juxtaspinal points are noted. Quickly join and accrue weakness in extremities up to steam - or tetraplegias, an ischuria, disturbances of sensitivity of conduction character. Meningeal symptoms are expressed unsharply. In blood the leukocytosis with shift of a formula to the left, the accelerated ROE comes to light. At bakte-riol. a blood analysis growth of pathogenic microflora can be received. By means of liquorodynamic tests (see), miyelografiya (see) or a radio isotope research find the full or partial block of a subarachnoid space, cerebrospinal liquid at the same time is a little changed. At a puncture of an epidural space at the level of an arrangement of abscess hmozht to be received pus. Hron. epidural abscess is characterized by less bystry increase of symptoms and a remittiruyushchy current.
The diagnosis is made on the basis of a triad of symptoms: existence of the suppurative or infectious focus in an organism, local radicular pains and symptoms of accruing S.'s prelum of m against the background of the general septic state (see. Sepsis ). Along with methods of a research of passability of a subarachnoid space the important role in diagnosis of epidural abscess is played by a termografiya (see), results indicate a cut existence of the inflammatory center.
Subdural abscess arises after the getting gunshot or chipped and cut wounds of a backbone which are followed by damage of a firm meninx and penetration into a subarachnoid space (on the wound channel) contagiums. In the beginning the phenomena of a spinal pia-arachnitis, and further, as a result of formation of commissures develop, there comes restriction of the inflammatory center and encapsulation of abscess. Clinically subdural abscess is shown resistant nevrol. disturbances in the form of paresis or paralyzes, gross violations of sensitivity and function of pelvic bodies. The diagnosis is made on the basis of data on character and localization of a wound, on the inflammatory process of S. of m (myelitis) or its covers (meningitis) postponed after wound with the subsequent blockade of a subarachnoid space.
Intramedullary abscess meets extremely seldom. Contagiums get into S. of m in the hematogenous way or at the spinal getting wounds. In a wedge, a picture radicular pains, a meningeal syndrome, the accruing S.'s prelum of m and symptoms of its cross defeat are characteristic. High temperature and the expressed changes in blood inherent to an inflammation, and pleotsntoz in cerebrospinal liquid are noted. By means of liquorodynamic tests or a piyelografiya reveal impassability of a subarachnoid space.
Treatment of abscess of S. of m operational; in the beginning make laminectomy (see). At epidural abscess empty an abscess and delete the changed epidural cellulose; the firm cover of S. of m is not opened and not punktirut. At subdural abscess open a firm cover of S. of m, separate commissures and hems between S. in m and the capsule of abscess, then delete abscess whenever possible entirely and take in tightly a firm meninx. At intramedullary abscess after opening of a firm meninx make cuts over the changed site C. of m a soft cover and delete pus; the cavity is washed out solution of an antiseptic agent and take in a firm meninx. The operational wound in soft tissues is irrigated with solution of antiseptic agents and taken in tightly, leaving only a microirrigator for the subsequent introduction of antibiotics. In the postoperative period antibiotics enter, besides, intramusculary and endolyum-balno.
The forecast is always serious. A timely operative measure at epidural abscess can lead to recovery. After removal of subdural and intramedullary abscesses usually note regress nevrol. symptoms. Extent of recovery of function depends on an otgranichennost of process, its prevalence and duration of existence.
Vascular diseases subdivide on hemorrhagic (see. Gemapgomiyeliya ), ischemic (miyeloishemiya) and combined. Carry to them also malformations of vascular system C. of m (aneurisms, vascular malformation of S. of m). On sovr. to data, vascular disorders in S. m are observed more often than it was considered earlier, but they are not always correctly diagnosed, quite often imitate inflammatory (acute and chronic myelites, spinal arachnoidites), degenerative (a side amyotrophic sclerosis), tumoral and not tumoral (myelosyringosis) defeats of S. of m. The main reason for mistakes in diagnosis at acute and chronic disorders of spinal blood circulation is the taken roots opinion that S. the m in comparison with a brain more rezistenten to ischemia, possesses richer vascular network with a multiple anastomosis. Studying of blood circulation of S. of m disproved this long existing point of view and demanded review of idea of a rarity of vascular defeats of S. of m.
The reasons of vascular defeats of S. of m are numerous and can be divided into several groups: 1) congenital anomalies of the vessels supplying with blood C. of m (coarctation of an aorta, arterial and arteriovenous aneurisms of S. of m); 2) the acquired changes of vessels (atherosclerosis of an aorta and its branches, the stratifying aortic aneurysm, arteritis, a nodular periarteritis, phlebitis, fibrinferments, embolisms of large radikulomedullyarny trunks, etc.); 3) disturbances of a system hemodynamics (decrease in the system ABP), in particular at a myocardial infarction, an idiopathic hypertensia (a so-called cardiospinal syndrome); 4) compression defeats of vessels, krovosnabzhayushchy S. of m (a prelum of an aorta and its branches tumors and opukholepodobny educations, a prelum of radikulomedullyarny and perimedullary vessels a protruded disk at osteochondrosis of a backbone, an epidural or subdural tumor, cicatricial and commissural process in S.'s covers of m, abnormal vertebrae, epidural inflammatory infiltrate, bone fragments at injury of a backbone, Pedzhet's disease, etc.). In special group allocate damages of vessels, krovosnabzhayushchy S. to m, at nek-ry operative measures (e.g., bandaging, coagulation or a section of radikulomedullyarny arteries at backbone operations, bandaging of segment branches of an aorta at operations for coarctation of the aorta stratifying aortic aneurysms, etc.) both nek-ry medical and diagnostic manipulations (e.g., epidural novocainic blockade, spinal peridural anesthesia, an aortografiya). In the majority of observations are combined various etiol. factors, it is the most frequent — atherosclerosis of an aorta and osteochondrosis of intervertebral disks.
Wedge, picture of disturbances of spinal blood circulation of a polimorfn; distinguish acute and its chronic forms. The acute miyeloishemiya can develop as a stroke or within 2 — 3 days; nevrol. symptoms can disappear completely in 2 — 4 weeks with recovery of functions C. of m or remain more resistant at development of a heart attack of this or that part C. of m Hron. spinal vascular insufficiency (an ischemic myelipathy) is characterized by the passing disorders of spinal blood circulation amplifying or arising at functional loads and disappearing at rest and also the progressing S.'s defeat in m. Passing frustration are shown by syndromes.
1. Unterkharnsheydt's syndrome — suddenly arising sharp weakness of hands and legs (tetraparesis), as a result a cut of the patient falls and at the same time faints on will pass several. After recovery of consciousness within 1 — 2 more min. there are no autokinesias, then gradually force in hands and legs is recovered to norm. Such attacks develop usually at sharp turns of the head owing to sudden ischemia in cervical segments C. of m and in a brain trunk (sometimes with switching off of function of a reticular formation).
2. A syndrome of sudden falling because of weakness of hands and legs, but without loss of consciousness. This syndrome is caused by passing ischemia in the field of a cervical thickening of S. of m
3. A syndrome of the myelogenetic alternating lameness (Dezhe-rin's syndrome) — emergence of sharp weakness in legs at the walking which is followed by feeling of numbness of legs and the bottom of a stomach, disorder of function of pelvic bodies. After rest within 5 — 10 min. the specified phenomena disappear and the patient can continue walking. The syndrome arises at the ischemia covering chest, lumbar and sacral segments C. of m 4. The syndrome of the kaudogenny alternating lameness which is characterized by the fact that during the walking at first there are paresthesias (a pricking, crawling of goosebumps, numbness, etc.) rising from distal departments of legs to proximal then soon joins weakness of the lower extremities, and the patient is forced to stop walking. Rest within 5 — 10 min. takes off these effects. The syndrome is caused by insufficiency of blood supply of roots of spinal nerves in a horse tail owing to the inborn or acquired narrowness of the vertebral channel, because of a thickening of arches of vertebrae (a syndrome In a roist) or prelums of a firm cover of S. of m surrounding a horse tail, a protruded disk at the lumbar level. Sometimes note a combination of the myelogenetic, kaudogenny and peripheral alternating lameness, a cut confirms development of occlusion in a lower part of a ventral aorta when ischemia in one step develops in S. of m, in roots of spinal nerves in a horse tail and in muscles of the lower extremities. 5. Passing upper or lower parapareses, and also tetraparesis, to-rye regress within the first days after emergence.
Wedge, displays of a heart attack of S. of m depend on its localization and are connected with defeat of the main vascular pools of S. of m. At obstruction of a front spinal artery there comes the necrosis of the forefront of S. of m. At the same time sharply or subacutely the lower spastic paraplegia with the dissociated para-anesthesia and dysfunction of pelvic bodies develops. For the first time this syndrome connected with ischemia of chest segments C. of m was studied by P. A. Preobrazhensky (1904). At damage of a front spinal artery at the level of cervical segments there is a sluggish or mixed paraparesis of upper extremities and a spastic lower paraparesis with the dissociated para-anesthesia and dysfunction of pelvic bodies for the central type. If the vascular pool is struck at the level of lumbosacral segments, a wedge, the picture is characterized by the lower sluggish paraplegia (paraparesis) with areflexia (see), dysfunction of pelvic bodies and the segmented and conduction dissociated para-anesthesia. The last symptom complex was for the first time described by L. M. Stanilov-sky (1905) and Tanon (L. Tapop, 1908). Ischemia of a front half of diameter of S. of m develops at obstruction not only the most front spinal artery, but also front radikulomedullyarny arteries creating it with their sources, including also an aorta.
At a syndrome of obstruction of a submersible (furrowed) artery ischemia arises in the corresponding half (right or left) S.'s diameter of m and Broun-Sekar's syndrome develops. Unlike compression or traumatic, Broun-Sekar's syndrome at this type of ischemia is characterized by lack of disorders of deep sensitivity on the party of paralysis since back cords krovosnabzhatsya from system of back radikulomedullyarny arteries.
If the center of a necrosis is located in one half of S. of m at the level of upper cervical segments, the subbulbar syndrome of Opalsky — gomolateralny anesthesia on a face, an alternating conduction hypesthesia of the dissociated type on a trunk and extremities develops; on the party of the center — the central paresis and an ataxy of extremities, sometimes Bernard's syndrome — Horner.
The syndrome of obstruction of a back spinal artery is for the first time described by Vilyamson (R. T. Williamson, 1895). At this syndrome the necrosis is localized in a zone of back cords, tops of back horns and partially back departments of side cords
of S. of m, taking a pyramidal way. There is a sensitive ataxy, moderate central paresis, the segmented hypesthesia is possible. At disturbance of blood circulation in system of a back spinal artery at the level of cervical segments there is a selective ischemic defeat of a bunch of Burdakh (a wedge-shaped bunch) or a bunch Gaulle (posterior pyramid) since these conductors are supplied with independent branches of a back spinal artery.
Due to the clarification in recent years of a role of large radikulomedullyarny arteries in S.'s blood supply of m became possible to differentiate the wedge, syndromes arising at switching off of nek-ry most important radikulomedullyarny arteries.
At a syndrome of arterial occlusion of a cervical thickening ischemia occupies ventral departments of cervical segments that is shown by sluggish paresis of upper extremities, the segmented and conduction dissociated para-anesthesia, a spastic lower paraparesis, dysfunction of pelvic bodies.
The syndrome of obstruction of a big front radikulomedullyarny artery of Adamkevich is characterized by ischemia of ventral departments of nizhnegrudny, all lumbar and sacral segments C. of m. In an acute phase of a stroke always find the lower sluggish paraparesis (paraplegia) dissociated or seldom total para-anesthesia with the upper bound at the level of ThIV_XI1, dysfunction of pelvic bodies (an incontience or an ischuria, a calla) and bystry development of decubituses. Further, at reduction of the ischemic phenomena, many symptoms are exposed to involution. The lower paraparesis gets signs of defeat of the central motor-neurons (also akhillova reflexes raise knee, appear patol.-foot signs), the level of disorders of sensitivity decreases, function of pelvic bodies improves.
The syndrome of obstruction of an upper additional radikulomedullyarny artery is characterized by acute development of the lower paraparesis, the dissociated para-anesthesia with the upper bound at the level of Th^n, an ischuria. In the first days die away knee and akhillova reflexes (see Bastian the law), however the reflex Babin-sky is always caused (see Babinsky a reflex). In the subsequent the lower paraparesis gains lines central, and later 2 — 3 weeks the hypotrophy of intercostal muscles at the level of the corresponding myotomes develops.
The syndrome of obstruction of the lower additional radikulomedullyarny artery which is usually accompanying a root of Lv or St of a spinal nerve often develops at hernia of nizhnepoyasnichny intervertebral disks. Ischemia at the same time is localized as in roots of the spinal nerves forming a horse tail and in ventral departments of lumbar and sacral segments C. of m, is the most frequent in segments of an epikonus and a cone. Clinically it is shown by sluggish paralysis of the muscles innervated from segments LIV — S „, disappearance of an akhillov of a reflex and reflex from a sinew of a long razgibatel of a thumb of a leg, a conduction parahypesthesia with the upper bound corresponding to the Lm_IV level of segments including an anogenitalny zone (on this background it is possible to reveal a strip of the general anesthesia connected with ischemia not only S. of m, but also certain roots as a part of a horse tail), an incontience or an ischuria and a calla. At the discogenic nature of an ischemic spinal stroke disappearance of a pain syndrome (giperalgi-chesky crisis) after development of paralysis and anesthesia is characteristic.
Disturbances of venous blood circulation of m develop in S. at arteriovenous aneurisms and other spinal vascular malfor-yation (see below), and also at phlebitis of epidural localization. Hernias of intervertebral disks at the level of cervical, chest or lumbar departments of a backbone are the most frequent reason of a venous miyeloishemiya; at the same time there can be a prelum not only veins, but also the most spinal cord. At disturbance of venous outflow the ischemic phenomena prevail in a dorsal half of diameter of S. of m: back cords, back horns, side cords with their pyramidal paths suffer. Therefore in a wedge, a picture at such patients preferential central paresis, the expressed koordinatorny frustration (sensitive and mixed are combined — the sensitive and cerebellar ataxy), dysfunctions of pelvic bodies, can arise Broun-Sekar's syndrome (see Broun-Sekar a syndrome). Quite often note expansion of saphenas in the field of a lumbosacral rhombus (at women — in the field of Mikhaelis's rhombus).
At the combined disturbance of arterial and venous circulation ischemia extends to all diameter of S. of m that is shown by the corresponding syndromes.
S.'s heart attacks of m develop approximately with an identical frequency at persons of both sexes, is frequent at working-age. More often the miyeloishemiya arises sharply, subacutely, less often slowly progresses. The passing disturbances of spinal blood circulation preceding development of a heart attack are characteristic. True hemorrhagic defeats of S. of m meet seldom. There is an opinion expressed by Tsyulkh (To. Ztilch, 1954) that the hematomyelia is a kind of the central spinal ischemic necrosis arterial venoznego origins (a red softening).
In diagnosis of a heart attack of S. of m assessment of a background has essential value, on Krom it develops (a protruded disk, damage of an aorta and its branches, inside - and extra vertebral tumors, parasitic diseases, etc.). An important role in diagnosis is played by a siondi-lografiya, a contrast and radio iso-topnaya miyelografiya, a spinal angiography, a venospondilografiya, a research of cerebrospinal liquid. At a spinal puncture with liquorodynamic tests and other researches in the first days after a spinal heart attack quite often define the block of a subarachnoid space which is a consequence of local hypostasis of S. of m. Note increase in amount of protein in cerebrospinal liquid to 1 — 2 °/00 (g/l). At a repeated research in 2 — 3 weeks of the phenomena of the block also the amount of protein in cerebrospinal liquid, as a rule, is not found, decreases.
Treatment of chronic and acute miyeloishemiya is carried out in two directions. First, apply the pharmaceuticals improving collateral circulation and microcirculation (an Euphyllinum, komplamin, nicotinic to - that, Cavintonum, Dibazolum), diuretics (lasixum, a mannitol), antiagregan-you (acetilsalicylic to - that), redoxons and groups B. Secondly, carry out the actions directed to elimination of occlusion. E.g., at S.'s heart attack of m caused by a thromboembolism of vessels apply anticoagulants (heparin, fibrinolysin, Streptokinasa, Phenilinum). At pathology of an aorta and its segment branches operational treatment can be carried out. In case of the compression and vascular nature of a heart attack of S. of m an early operative measure is shown.
In the period of recovery appoint physiotherapeutic procedures (diadynamic currents to sympathetic nodes with tselyo desimnati-zation of spinal vessels and improvement of collateral circulation), massage to lay down. gymnastics. Carry out treatment by resorptional means (an aloe, a vitreous, Cerebrolysinum, lnda-for), the drugs stimulating conductivity of nervous impulses (prozerin, Galantaminum, etc.), vitamins of group B, nicotinic to - that.
The forecast of an ischemic heart attack of S. of m depends on the reason which caused it and a method of treatment. Practical recovery or considerable improvement is observed almost at 2/3 patients. Approximately 20% of patients have permanent disturbances and regress of symptoms of defeat of S. of m is not noted. The lethal outcome happens the investigation of an urosepsis, a myocardial infarction, a rupture of an aortic aneurysm, multiple thromboembolisms in internals, a brain, etc.
Preventive actions include timely elimination etiol. factors, such as formation of a protruded disk (strengthening of a muscular corset, the correct employment of persons with passing symptoms of a miye-loishemiya), long reception of anti-sclerous means (Prodectinum, iodide drugs, Diosponinum, Miscleronum, etc.), treatment of defeats of cardiovascular system.
Aneurisms of vessels of a spinal cord. Thanks to use of a spinal angiography it is established that a main type of aneurisms of vessels of S. of m are arteriovenous aneurisms (see Aneurism), to-rye carry to inborn malformations (malfor-mation) of vessels of S. of m. Before them called an angioma, a racemose angioma, the curling angioma, an angiodisgene-tichesky myelomalacia, varicosity of vessels of a spinal cord, etc.
The pathogenetic factors defining the main a wedge, displays of arteriovenous aneurisms of S. of m are: a prelum and mechanical irritation of S. of m the vascular conglomerate which is in pozvonochnokhm the channel, and hron. insufficiency of regional spinal blood supply owing to continuous arteriovenous shunting (direct dumping of blood from arterial in a venous bed, passing a capillary network of S. of m). The last leads to a hypoxia and developing of perifocal hypostasis of S. of m. Arteriovenous aneurisms in the course of growth of an organism progress usually slowly, however the blood stream in them gradually increases, generally in a venous part that conducts to a sharp phlebectasia. As a result of changes of a hemodynamics in arteriovenous aneurism at 25 — 30% of patients hemorrhages develop in a subarachnoid space (see. Gematorakhis ) or in fabric C. of m (see. Hematomyelia ). In 60 — 70% of observations of hemorrhage arise repeatedly. Subarachnoidal hemorrhage is characterized by sharply developing pain radicular syndrome at the level corresponding to it. Appear tension of juxtaspinal muscles of a back (hl. obr. the muscle straightening a backbone), meningeal symptoms, sometimes — the all-brain phenomena, fervescence. At parenchymatous hemorrhage (in fabric C. of m) there is a picture of full or half cross defeat of S. of m with Broun-Sekar's syndrome. Quite frequent complication of arteriovenous aneurisms which is caused their gap is the hematomyelia with extensive damages of S. of m.
In the period between hemorrhages in one observations note complete or partial recovery of the lost functions, in others — gradual increase nevrol. symptoms. In most cases at S.'s aneurisms of m the course of a disease progressing with deteriorations and remissiyakhm, a wedge, a picture of opukholepodobny process. Local symptoms depend on the level of defeat, its extent on the diameter and S.'s longitudinal axis of m. At blood supply of arteriovenous aneurism from vertebral arteries in a wedge, a picture because of secondary hemodynamic disturbances symptoms of defeat of a back cranial pole can appear.
In cerebrospinal liquid find increase in quantity of cells, in most cases — increase in protein content; at subarachnoidal hemorrhage — impurity of blood.
Diagnosis is difficult. Earlier the diagnosis of arteriovenous aneurism of S. of m was made in most cases only during operation for an estimated tumor of S. of m.
At rentgenol. a research in rare instances on a spondilogramma reveal the signs characteristic of volume process of S. of m. By means of a miyelografiya (see) sometimes it is possible to find the defect of filling of a subarachnoid space having the gyrose form. However similar results can be received as well at S.'s arachnoiditis of m and nek-ry intramedullary tumors. The only diagnostic method of arteriovenous aneurisms of S. of m is the selection spinal angiography, at a cut carry out selective contrasting of intercostal, lumbar arteries and branches of subclavial arteries for establishment of all sources of blood supply of aneurism, its localization, the sizes and outflow tracts. On the angiogram on the .fena melkopyatnnsty patol. networks of vessels are visible sites of a dense contrast shadow due to stratification of shadows of the wide gyrose bringing and taking-away vessels or as a result of a temporary delay of a contrast agent in expanded cavities of the aneurism (fig. 10, a). The number of the vessels feeding aneurism fluctuates from 1 to several, located at the different levels C. m. Outflow of blood comes from arteriovenous aneurism on front, back and radicular veins of S. of m. In cervical part C. of m blood supply of aneurism can be carried out from radikulomedullyarny arteries and a front spinal artery; in verkhnegrudny — from short radikulomedullyarny arteries and a front spinal artery; in nizhnegrudny and lumbar departments — generally from the increased big radikulo-medullary artery of S. of m (Adamkevich's artery).
Treatment of arteriovenous aneurisms of S. of m operational. At early diagnosis and by means of the microsurgical equipment total removal of arteriovenous aneurism became possible. Operation is performed under an intubation anesthesia. The laminectomy (see) is made at the level of an arrangement of aneurism and under an operative microscope delete a vascular conglomerate. Total removal of aneurisms is possible when they have the small sizes and are located on back and side surfaces of S. of m or at the level of a horse tail. In these cases widely apply endovazalny switching off of arteriovenous aneurism from S.'s blood supply of m by means of endovascular embolization of the bringing vessels, a cut it is possible to carry out at any level C. of m irrespective of the number of the bringing vessels and prevalence of aneurism (see. X-ray-endovascular surgery ). In the bringing vessel of aneurism on the probe entered into it physiological solution push small emboluses from an absorbable gelatin sponge (or other thrombosing substances). In the course of embolization to an aneurysm repeatedly contrast on a TV screen and angiograms (at introduction of small doses of a contrast agent). Embolization is continued before switching off of aneurism from a blood-groove, at preservation of a gleam of the bringing vessel. In the subsequent make a control angiography for definition of extent of switching off of aneurism from a blood-groove (fig. 10, b).
The forecast is favorable if before operation irreversible changes were not caused by a hematomyelia or long ischemia of S. of m yet. Regress nevrol. symptoms is defined in the first weeks after embolization or operation.
Arterial (meshotchaty) aneurisms of vessels of S. of m find extremely seldom, generally at a spinal angiography in patients with subarachnoidal hemorrhages. Clinically this pathology of S. of m is shown by the repeated subarachnoidal hemorrhages which are followed by radicular and meiingealny syndromes; at parenchymatous hemorrhage symptoms of local defeat of S. of m at the level of an arrangement of aneurism develop. Treatment operational. The forecast at timely treatment favorable.
Degenerative and dystrophic defeats
observe Degenerative and dystrophic defeats of structures of S. of m at a number of hereditary diseases (see. Amyotrophy , Ataxy , Paraplegia ) and at metabolic disturbances (see. Funicular myelosis ). The defeat of back cords of S. of m inherited on autosomal dominantly type (Peron's syndrome — the Woadwaxen — the Pendent) which is clinically shown disturbance of deep and tactile sensitivity, an astereognosis, lack of Achilles reflexes and trophic extremity ulcers with is described swelled up a little an aniye of metacarpophalangeal and metatarsophalangeal joints, peri-articulary osteophytes and trophic changes of nails. Development of gliomatozny process and education patol. cavities in gray matter C. of m it is noted at myelosyringoses (see).
Parasitic diseases meet seldom. E.g., cysticercosis (see) S. the m makes 1 — 4% of all defeats by a cysticercus of c. N of page. The oncospheres brought in S. by m in the hematogenous way are localized in a soft meninx, on roots in a horse tail less often in epidural cellulose. The m which got to S. on likvorny ways of an oncosphere are located in a subarachnoid space, a thicket in cervical part C. of m. Around them there is an aseptic inflammatory process (a productive arachnoiditis). Klien, picture is not specific and is shown by radicular pains, about l ochechny symptoms; at the expressed adhesive shell process there is paresis, disturbances of sensitivity and function of pelvic bodies. At liquorodynamic tests (see) note the partial or full block. In cerebrospinal liquid in the period of an aggravation find kletochnobelkovy dissociation with a pleocytosis and existence of eosinophils; in blood — an eosinophilia. In diagnosis reaction of binding complement of blood and cerebrospinal liquid with tsistitserkozny antigen, and also the helmintologic anamnesis and inspection on existence of eggs of a pork tapeworm in Calais is of great importance. A characteristic diagnostic character is detection of calciphied tsistitserok in soft tissues at a X-ray analysis.
Treatment operational. The main indications for it are symptoms of a prelum of S. of m with the block of a subarachnoid space, and also persistent pains. After a laminectomy open a firm meninx and separate unions between covers, a spinal cord and its roots (meningo-miyeloradikuloliz). At detection of bubbles of a cysticercus they are deleted entirely. In the postoperative period make repeated spinal punctures before normalization of composition of cerebrospinal liquid.
The forecast depends on prevalence of defeat of S. of m, and also expressiveness of an arachnoiditis (see). At single tsistitserka the forecast can be favorable.
S.'s echinococcosis of m is found extremely seldom and usually is secondary in relation to an echinococcosis of a backbone (see) and the fabrics surrounding it. Usually single-chamber echinococcus (an echinococcal bubble) is located on a big extent of the vertebral channel and a thicket in chest department.
The wedge, a picture similar to clinic of a tumor consists of symptoms of accruing S.'s prelum of m, to-rye develop much quicker, than at a tumor. Bystry transition of spastic paralysis in sluggish, and also a prematurity of the general exhaustion of the patient (a gidatidozny cachexia) is characteristic. During a disease remissions can be observed. At liquorodynamic tests reveal the partial or full block of a subarachnoid space, in cerebrospinal liquid — proteinaceous and cellular dissociation. Echinococcus elements in cerebrospinal liquid (kryuchya, a scolex) find seldom. In blood quite often observe an eosinophilia. Skin and anaphylactic test of Kasoni has diagnostic value (see. Echinococcosis ).
Treatment operational. Make a wide laminectomy with removal of an echinococcal bubble; the surgery field in order to avoid planting is carefully isolated. The result of operation is more favorable at the small sizes of a bubble of an echinococcus, i.e. at early diagnosis. The forecast depends on degree of a prelum of S. of m and the general condition of the patient (degree of intoxication, exhaustion).
Such parasitic defeats as a coenurosis, a schistosomatosis (bilgartsinoz), paragonnmoz S.'s (liver helminth disease) of m, develop extremely seldom. A coenurosis (see) and a paragonimiasis (see) are clinically shown by a syndrome of a prelum of S. of m, and schistosomatosis (see), at Krom of egg of a parasite find in fabric C. of m — a hemorrhagic myelitis. Treatment at S.'s prelum of m the operational, including removal of parasitic cysts, division of commissures and recovery of normal circulation of cerebrospinal liquid, and also — specific, antiparasitic. The forecast in the majority of observations — adverse, it depends on quantity patol. the centers, extent of defeat of covers and substance C. of m
carry new growths To S.'s tumors of m, to-rye develop both in the tissue of a brain, and from a meninx, roots of spinal nerves, vessels, an epidural fatty tissue, etc. S.'s tumors of m make 10 — 12% of all tumors of c. N of page. Men and women get sick equally often.
S.'s tumors of m can be intracerebral, or intramedullary (apprx. 20%), and extra brain, or extramedullary (apprx. 80%). Nearly 80% of intramedullary tumors make high-quality gliomas — the tumors growing from cells of the neuroglia which is interstitial tissue of a brain and having an ectodermal origin (see. Brain, tumors ). Generally are ependymomas (see) or astrocytomas (see). Much less often malignant intramedullary tumors — glioblastoma (see), medulloblastomas (see), metastasises of cancer (see) various bodies meet. Extramedullary tumors approximately with an identical frequency are presented by neurinoma (see) and meningiomas (see); sarcomas, angioblastomas, lipomas are much less often observed. In relation to a firm cover of S. of m extramedullary tumors divide on subdural, epidural and is rare — episub-dural, located both over and under a firm meninx. In 4 — 8% of observations of a tumor have the form of hourglasses and are located at the same time partially in the vertebral channel, partially parabeliefs-tebralno (fig. 11).
Wedge, picture of tumors of S. of m consists of three groups of symptoms: radicular, segmented and conduction. Radicular symptoms — the expressed persistent pains in a zone of the struck root which are quite often sharply amplifying in a prone position; the patient is forced the most part of time to stand or sit — the symptom of radicular pains of situation characteristic of extramedullary tumors (is more often than neurinoma) and especially tumors of a horse tail. At intramedullary tumors of pain, as a rule, are absent, disorders of sensitivity yablyudatsya. The wedge, a picture depends on at what level the tumor what nervous cells or the centers, conductors are in the struck segments is located.
At nevrol. inspection of the patient with S.'s tumor of m it is possible to reveal also other characteristic symptoms: a symptom of an acantha (Razdolsky's symptom) — emergence or strengthening of pains at effleurage on an acantha of a vertebra, at the level to-rogo in the vertebral channel the tumor, and emergence of paresthesias from top to bottom from the level of its arrangement is located (it is characteristic of extramedullary tumors); symptom of a likvorny push (Razdolsky's symptom) — strengthening of radicular pains at the level of an arrangement of a tumor at a prelum of jugular veins; a symptom of a vklineniye — temporary or permanent increase of conduction disturbances after a spinal puncture with extraction of cerebrospinal liquid. The last two symptoms arise in the presence of the partial or full block of a subarachnoid space and tumors owing to the arising difference of pressure of cerebrospinal liquid higher and lower than the level of a tumor, irritation of the struck root or an additional prelum of underlying site C. of m and the vessels supplying it have a talk with development of a miyeloishe-miya shift extramedullary (a thicket subdural).
In a wedge, the course of a disease distinguish three main stages: radicular, or pseudo-neuralgic, characterized by existence of radicular symptoms; a stage of development of half defeat with Broun-Sekar's syndrome at a preferential prelum of one half of S. of m; a stage of steam - either tetraparesis, or a paraplegia (or tetraplegias), at a prelum of all diameter of S. of m at the different levels.
Level of an arrangement of a tumor is diagnosed by data nevrol. inspection and tool researches: a X-ray analysis of a backbone (see) or its tomography, a contrast, radionuclide miyelografiya (see), a computer tomography (see the Tomography computer), elektrofiziol. to researches, etc.
The top level of an arrangement of a tumor is defined on the basis of localization of radicular pains, the upper bound of disorders of sensitivity, disturbances of movements and reflexes. Diagnosis of the lower level is clinically more difficult and is based on change of reflexes, in particular protective, but generally — on data of additional methods of a research.
Establishment of an arrangement of a tumor — intra-or extramedullary is of great importance. At intramedullary tumors of disturbance of sensitivity in a zone of the struck segments have the dissociated character in the beginning, in process of accession of conduction disturbances note the descending type of disturbances of sensitivity, early emergence of disorders of function of pelvic bodies. Radicular symptoms, and also symptoms of an acantha, likvorny push and vklineniye can be absent or be slightly expressed.
Course of tumoral process progressing.
The diagnosis is established on the basis by a wedge, currents, data nevrol., rentgenol. and other methods of a research.
At a X-ray analysis find changes of a backbone in the form of expansion of the vertebral channel or thinning of legs of arches of vertebrae at the level of an arrangement of a tumor in 35 — 40% of patients (Elsberg's syndrome — the Dyke) up to their final fracture; sometimes find expansion of an intervertebral foramen on the party of a tumor (fig. 12). By means of liquorodynamic tests reveal the partial or full block of a subarachnoid space, proteinaceous and cellular dissociation in cerebrospinal liquid. At a venospondilografiya note a partial or full neza-polneniye of intraspinal veniplexes up to break them at the level of an arrangement of a tumor and compensatory vasodilatation of an outside vertebral veniplex (fig. 13). Apply a miyelografiya with use of heavy contrast agents (fig. 14) or air to confirmation of the diagnosis and establishment of level of an arrangement of a tumor — a pnevmomiyelografiya (see), and also a radionuclide miyelografiya.
The differential diagnosis is carried out with a spinal arachnoiditis (see) and a cyst. The long current with remissions, various extent of disturbances of movements, sensitivity and function of pelvic bodies, lack (usually) total block of a subarachnoid space and proteinaceous and cellular dissociation in cerebrospinal liquid is characteristic of a spinal arachnoiditis. S.'s cyst of m on a wedge, a picture is similar to an intramedullary tumor; quite often the diagnosis can be made only during an operative measure. At differential diagnosis of tumors of S. of m consider also a possibility of parasitic defeats, to-rye can give opukholepodobny syndromes, and also a diskosis (see).
Treatment operational. The volume of operation depends on the nature of a tumor, its arrangement and prevalence. After a laminectomy (see) carefully allocate top and bottom poles, and also free edge ekstraduralno to the located tumor from surrounding fabrics. In most cases such tumors delete considerably. At a subdural extramedullary arrangement open a firm meninx on the centerline throughout a tumor.
During removal meiingioma (see) it must be kept in mind a possible community of segmented blood circulation of S. of m and a tumor. The meningioma can acquire roots of spinal nerves. Removal of a big meningioma of S. of m sometimes demands crossing of one or two roots. However during removal of a meningioma at the C4 level — Th4, L1 of it it is necessary to avoid since crossing of radikulomedullyarny arteries considerably worsens blood supply of a part of segments C. of m. In such cases recommend to remove after crossing of a gear sheaf a tumor in parts.
During removal of neurinoma (see) at first remove an arachnoid membrane over a tumor that allows to establish its relationship with surrounding fabrics. After allocation of a tumor the root is crossed, previously having entered into it 0,5% solution of novocaine for the purpose of prevention of a metastasis ad nervos of blood circulation.
At craniospinal tumors (see) quick access shall provide opening of a back cranial pole and a laminectomy in upper cervical vertebras. After opening of a firm cover of S. of m and detection of the lower pole of the tumor extending in a back cranial pole, the section of a firm meninx is continued over area of the big (cerebellar and brain) tank and a cerebellum before detection of an upper pole of a tumor.
At neurinoma and neurofibromas like hourglasses operation is begun with an extradural part of the tumor which is located in the vertebral channel. For removal of an isthmus of a tumor resect the bases of legs of arches and joint shoots of the vertebrae lying above and below a root, from to-rogo the tumor proceeds. For removal of an ekstravertebralny part of a tumor expand an operational wound with cross section of skin and longitudinal muscles of a neck or back.
Tumors of a horse tail (kaudomedullyarny tumors) which are often reaching the big sizes and the acquiring roots of a horse tail, delete in parts and not always considerably. Also difficult and most often a radical operative measure concerning S.'s lipoma of m is impossible.
At intramedullary tumors after opening of a firm cover of S. of m make its longitudinal section on the centerline to a surface of a tumor. New growths of the small sizes and a dense consistence delete by means of a spoon (entirely or in parts). Small bleeding from a bed of a tumor is stopped the wadded or gauze ball moistened in hydrogen peroxide or warm physiological solution. After a radical oncotomy the firm cover of S. of m is sewn up tightly. At the big extent and infiltriruyushchy growth of a tumor operation is limited to a longitudinal section of S. of m over a tumor, its biopsy or only a decompressive laminectomy with broad opening of a firm meninx. In the postoperative period for the purpose of recovery of passability of a subarachnoid space and prevention of the subsequent commissural process carry out repeated spinal punctures with removal of cerebrospinal liquid.
Radiation therapy is shown at intramedullary radio sensitive tumors of S. of m (a dedifferentiation astrocytoma, an ependymoma, an ependymoblastoma, a meningosar-coma, an angioretikulema), radical operational removal to-rykh is impossible. Due to the deep bedding patol. the center use gamma and therapeutic devices or linear accelerators. Radiation is carried out from two juxtaspinal fields at the direction of a bunch at an angle 25 — 30 ° to a long axis of the vertebral channel. Width of fields 40 — 50 mm, length — on 1 — 2 segment exceeds clinically established extent of a tumor of S. of m. A total focal dose of 4000 pad (40 Gr) at a single dose of 200 pad (2 Gr). Planning radiation, consider the fact that the marginal dose for not struck fabric C. of m makes 3000 — 4000 pad (30 — 40 Gr) at fractional irradiation.
At a medulloblastoma of a cerebellum in a complex to lay down. actions enters, in addition to postoperative radiation of area of a back cranial pole and all S. of m in the dose to 2000 pad (20 Gr) brought in 20 days, radiation for the purpose of impact on the tumor cells which are in a face-vornykh S.'s spaces of m. Radiation therapy with the palliative purpose carry out at innidiation of these tumors to S. m — fractionation irradiate the area corresponding to an arrangement of metastasises in a dose to 3500 pad (35 Gr). In the course of treatment regress nevrol is noted. symptoms and reduction of pains. At a recurrence conduct repeated courses of radiation therapy not less than 5 — 6 months later taking into account doses of the first course of radiation.
The forecast depends on a histologic form of a tumor, its arrangement and prevalence. Almost at 50% of patients after operation comes full, and at 20% — almost absolute recovery, at 25% of patients, generally with the malignant tumors (which are especially located intramedullyarno), improvement happens temporary or it is not noted at all. The postoperative lethality makes apprx. 5%.
Operations on S. m make the GENERAL PRINCIPLES of OPERATIONAL TREATMENT concerning malformations, injuries of a backbone and S. of m, tumors and other volume processes in the vertebral channel breaking circulation of cerebrospinal liquid (vascular malforma-tion, parasitic defeats) and also at inflammatory diseases (abscess, arachnoidites, etc.). Due to the development of functional neurosurgery operative measures carry out also at patients with pain syndromes and the spastic phenomena (see the Commissurotomy of a spinal cord, the Myelotomy, Xopdomomiya), and also at dysfunction of a bladder. A number of operative measures carry out with use of a microsurgical method (see Microsurgery).
Training of patients for operation usually includes introduction to the patient of antihistaminic drugs (Dimedrol, Pipolphenum), analgetics and atropine. At craniospinal defeats narcotic analgetics do not apply in connection with danger of disturbance of breath. At a spine injury and S. of m if operation is made in the acute period, for reduction of hypostasis of S. of m use saluretics and osmotic diuretics. For the purpose of prevention of postural reactions of blood circulation, development to-rykh perhaps at change of position of the patient on the operating table, turn of patients is recommended to carry out at the lowered head end of an operational sgol.
At operations on S. m apply the combined anesthesia, and also local anesthesia of 0,5% solution of novocaine of reflexogenic zones of skin, a firm cover of S. of m in the field of roots of spinal nerves. The introduction anesthesia is carried out intravenous administration of 10% of solution of barbiturates. After introduction of the depolarizing muscular relaxants (e.g., a suktsinilkholina) make an endotracheal intubation and include artificial ventilation of the lungs. The anesthesia at the same time should be supported at the level of a stage. Use mixes of nitrous oxide with oxygen and Ftorotanum or a neyroleptanalgeziya. Diagnostic operations make under local anesthesia.
Quick accesses to S. of m shall provide a sufficient exposure of an affected area and at the same time possible preservation of joint shoots of the vertebrae performing basic function. The quantity of the acanthas which are subject to removal and arches of vertebrae depends on the estimated level of defeat and extent patol. process. An important stage of operation is makrosko-shshesky diagnosis patol. process on naked S. m, at a cut pay attention to color of a meninx and S. m, their vascularization and a consistence, to a form C. of m, its provision and character of shift and deformation. These data in many respects define the further course of operation. Pages of m take away flexible pallets, being careful in so-called critical ranges where and conditions of blood circulation are normal are adverse (segments CIV, Thlv and Thx — Lj). Throughout all operation C. of m irrigate with physiological solution. At operations on S. of m there is a need to excise an arachnoid membrane for recovery of a likvoroottok and elimination of unions that demands the maximum care in connection with possible bleeding. The arisen bleeding is stopped, putting the tampons moistened with hydrogen peroxide or a piece of a muscle (with the subsequent its removal). Electrothermic coagulation and cliping are not recommended. Isolation of a subarachnoid space of S. of m from possible flowing of blood for the purpose of prevention of development of a postoperative leptomeningeal fibrosis is obligatory. After an oncotomy or another objvkhm-ny patol. the center and emptying of l of ikvorosoderzhashchy spaces strengthening of bleeding from veins eppduralyyugo spaces is possible. Bleeding is stopped, putting a piece of a muscle.
Before mending of a wound check passability of subarachnoid spaces of S. of m by a prelum of jugular veins: in the absence of the block cerebrospinal liquid freely expires from upper parts of a subarachnoid space.
The firm cover of S. of m is sewn up with a continuous tight suture. Occasionally at operations on S. the m create defects of a firm cover; the plastics of defects is carried out by stratification of a cover near defect or use an aponeurosis or a fascia in the field of an operational wound, and also allotransplants of a firm meninx.
During removal of tumors, vascular malformation, operations on conduction paths of S. of m, etc. good illumination of a surgery field and use of special microsurgical tools is necessary.
In the postoperative period (see) overseeing by function of breath and cordial activity, purpose of anesthetics is necessary. At the expressed pain syndrome the anesthesia can be applied by nitrous oxide. In the first 2 — 3 days for the purpose of prevention of pneumonia put cups or mustard plasters. In case of a long delay of an urination carry out electrostimulation of a bladder or 1 — 2 session of an ionophoresis with Pilocarpinum on area of a bladder. Constant catheterization of a bladder by means of a double-thread catheter is shown to patients with S.'s damage by m and dysfunction of pelvic bodies, one course to-rogo serves for constant irrigation of a bladder as antiseptic solutions, and another — for its emptying. It allows to avoid infection of urinary tract for a long time. Besides, each 2 — 3 months carry out cycles of treatment by antibiotics of a broad spectrum of activity taking into account sensitivity of microflora to them of urine, enter antiseptic agents (furadonin, 5-HOK, Nevigramonum).
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D. K. Bogorodinsky, A. A. Skoromets; E. I. Babichenko (malformations, abscess of a spinal cord, parasitic diseases, PMC.), I. D. Virozub (operation), II. G. Kostiuk (physical.), F. M. Lyass (I am glad.), E. I. Minakova (blood circulation, mt! issl.), V. A. Morgunov (stalemate. - An.), V. yu! Pervushin (An., comparative anatomy, gist., embr.), V. I. Rostotskaya (spinal hernias), T. P. Tiseen (aneurism of vessels of a spinal cord), S. S. Shifrin: (rents.).