CEREBELLUM [cerebellum (PNA, JNA, BNA)] — the department of a brain relating to a metencephal. Also the ranovesiya of a body participates in coordination of movements, regulation of a muscle tone, preservation of a pose. At the highest animals and the person consists of an unpaired worm (vermis) and pair hemispheres (hemisplieria cerebelli).
- 1 The COMPARATIVE ANATOMY AND EMBRYOLOGY
- 2 ANATOMY
- 3 HISTOLOGY
- 4 PHYSIOLOGY
- 4.1 History of studying of functions of a cerebellum
- 4.2 Participation of a cerebellum in regulation of functions of an organism
- 4.3 The functional organization of a cerebellum (localization of functions in a cerebellum)
- 4.4 the Role of a cerebellum in activity of a cerebral cortex, its functional linkages with other structures
- 5 METHODS of the RESEARCH
- 6 PATHOLOGICAL ANATOMY
- 7 PATHOLOGY
- 8 CEREBELLUM OPERATIONS
The COMPARATIVE ANATOMY AND EMBRYOLOGY
M. appears in a class of Cyclostoma at lampreys in the form of the cross plate which is thrown through front department of a rhomboid pole. The structural organization M. is similar at all vertebrata, but its form and the sizes strongly vary depending on a way of movement of animals. At fishes in M. the pair auriform parts connected with side and predoor nerves and the unpaired body receiving fibers from a spinal cord are allocated. The m of amphibians is rather small. At reptiles and birds M.'s body whereas auriform parts remain rudimentary is strongly developed. Development of hemispheres of M. connected by means of kernels of the bridge with new bark is characteristic of mammals. Hemispheres form phylogenetic new part M. (neocerebellum), and ancient M. (paleocerebellum) of subordinate animals is a part of a worm. The oldest department of M. is the flokkulonodulyarny share (archicerebellum), homologous to auriform parts M. of fishes.
At an embryo of the person the cerebellar rudiment is formed on 6 — the 7th week in the form of the rhombic lips located in a dorsolateral (krylny) plate on border with a roof of a metencephal. In the beginning the cerebellar rudiment presses in a cavity of the fourth ventricle (fig. 1). Its medial parts merge on the centerline, forming a worm, and from lateral parts hemispheres develop. Over a marginal layer of a cerebellar rudiment the surface bark remaining until the end of the pre-natal period is formed. Migration of neuroblasts happens in two directions; from a cover layer to M.'s surface, and from surface bark in more deeply the lying layers. As a result of it final bark with opposite orientation of axons at various types of nervous cells forms. From a cover layer kernels of M are allocated. Before everything M.'s connection with a predoor nerve and its kernels, then with a spinal cord is established with kernels of the bridge later. Myelinations of nerve fibrils at a fruit begins in a grub and after the birth extends to hemispheres. M.'s cracks begin to appear on the 3rd month of pre-natal development on a grub and from here pass to hemispheres; the final relief of a surface of M. is established on the 7th month. After M.'s birth quickly grows; its weight in relation to all brain increases from 5 — 6% at the newborn to 10 — 11% at the adult.
The m lies in a back cranial pole of a kzada from a myelencephalon and the bridge, forming a part of a roof of the fourth ventricle. The upper surface of M. is turned to occipital shares of hemicerebrums, from to-rykh it the firm cover of a brain separates — it is mashed a cerebellum. Below M. approaches a big occipital opening. On the surface of the head of M. it is projected between an outside occipital ledge and the basis of a mastoid. M.'s weight of the adult makes 136 — 169 g.
Passing according to M. of a crack (fissurae cerebelli) divide it on in parallel the located leaves (folia cerebelli), to-rye are grouped in segments (tsvetn. fig. 2, 3). To each segment of a worm there correspond certain segments of hemispheres (tab).
Table. Anatomic ratios of segments of a worm and hemispheres of a cerebellum
With funkts, the points of view in M. distinguish front, back and flokkulonodulyarny shares. Front and back shares are divided by a deep first crack (fissura prima), edges passes between quadrangular and simple segments.
The Flokkulonodulyarny share is delimited by a posterolateral crack (fissura dorsolateralis) located on a lower surface of M.
M.'s surface is covered with bark (cortex cerebelli). The white matter located under it makes a brain body of M. (corpus medullare) and enters leaves in the form of white plates (laminae albae), to-rye on sagittal sections give a peculiar branching picture of «a tree of life» (arbor vitae cerebelli). In a brain body M.'s kernels are put: gear (nucleus dentatus), cork (nucleus emboliformis), spherical (nuclei globosi) and kernel of a tent (nucleus fastigii), or Kelliker's (fig. 2) kernel.
The m has three pairs of legs. Lower cerebellar legs (pedunculi cerebellares inf.) go to to a myelencephalon (see), average cerebellar legs (pedunculi cerebellares medii) — to the bridge (see. Bridge of a brain ), upper cerebellar legs (pedunculi cerebellares sup.) — to a roof mesencephalon (see).
M.'s covers have the same structure, as well as in other departments of a brain (see. Meninx ).
Blood supply M (fig. 3) carry out upper, lower front and lower back cerebellar arteries; the number, the beginning and their distribution are changeable. Arteries of both parties anastomose among themselves, forming superficial arterial network, from a cut short branches in bark and longer in white matter depart and to M. Vena M. kernels are even more changeable, their number fluctuates from 6 to 22. Intra cerebellar veins are subdivided into veins of bark, white matter and kernels of M. Venous outflow comes from verkhnemedialny part M. in a big vein of a brain, from a zadnemedialny part — in a direct sine or a sinus drain, from anterolateral departments — in stony sine, from posterolateral departments — in a cross sine.
See also Brain, blood supply .
M.'s bark has thickness from 1 to 2,5 mm, its surface makes 85 000 mm2. Throughout a structure of bark equally, in it distinguish layers: superficial molecular (stratum moleculare), deep granular (stratum granulare) and the layer of pear-shaped neurocytes located between them, or a ganglionic layer (stratum ganglionare — fig. 4). The last is formed located in one row large (to 40 microns in the diameter) by pear-shaped neurocytes (Purkinye's cell). Pear-shaped neurocytes meet only in M.; consider that their quantity makes 15 — 26 million. Dendrites of pear-shaped neurocytes rise in a molecular layer, forming the dense, covered with spinules branchings in the plane, perpendicular M. Akson gives to the direction of leaves collateral branches to the next pear-shaped neurocytes and leaves in white matter.
The molecular layer contains the trailer branchings of nerve fibrils from other layers of bark and white matter forming in it a rectangular space lattice. Korzinchaty neurocytes (neurocytus corbifer) are characteristic of this layer, long axons to-rykh form on pear-shaped neurocytes of a texture in the form of baskets. Except them, in a molecular layer there are star-shaped neurocytes (neurocytus stellatus) with short axons.
The granular layer contains a huge number (on a nek-eye to data to 100 billion) nervous cells, ground mass to-rykh is made small (4 — 7 microns) by granular neurocytes (cells grains). Their dendrites form near a body of a cell trailer branchings in the form of bird's pads, axons rise in a molecular layer, T-shapedly share and pass on length of leaves, forming synapses with dendrites of pear-shaped neurocytes (1: 300) and korzinchaty neurocytes (1: 30). Distinguish 3 types of big granular neurocytes of a granular layer (Golgi's cells): 1. Korotkoaksonny star-shaped neurocytes. Their dendrites branch in a molecular layer in the plane, perpendicular to branchings of dendrites of pear-shaped neurocytes. Axons form branchings near a cellular body. 2. Dlinnoaksonny star-shaped neurocytes, dendrites to-rykh branch in a granular layer, axons leave in white matter as assotsiatsionny and probably komissuralny fibers. 3. The horizontal spindle-shaped neurocytes located under a layer of pear-shaped neurocytes.
Their long axons, having passed on a granular layer, are lost in white matter. In a granular layer there are special educations — cerebellar balls (glomeruli cerebellares), or parenchymatous islands Gel yes, having an appearance of the deprived kernels of cells. In balls branch and shoots of granular neurocytes, star-shaped neurocytes and afferent fibers (fig. 5) come among themselves into contact.
Glial elements of bark M. belong to astrocytes, oligodendrocytes and a microglia. So-called lofogliotsita are characteristic of M. (a cell with the sultan); their numerous shoots penetrate a molecular layer and support dendrites of pear-shaped neurocytes (bergmannovsky fibers). In white matter astrocytes meet.
White matter M. contains assotsiatsionny, komissuralny and projective fibers. Assotsiatsionny fibers connect the next leaves (girlyandovidny fibers of Shtillinga), and also bark of various segments of one hemisphere. Komissuralny fibers connect opposite hemispheres. Projective fibers connect M. to other parts of a brain, and also bark and kernels of M.
Afferent fibers of M. happen two types — mossy (mossy) and lianoid (climbing). Mossy fibers approach cerebellar balls where come into contact with neurocytes of a granular layer. The last are connected with pear-shaped neurocytes by means of parallel fibers and through korzinchaty cells. Lianoid fibers contact to pear-shaped neurocytes, braiding their dendrites, and only one fiber is the share of each neuron. The majority of afferent ways comes to M. on his lower and average legs; their distribution generally corresponds to phylogenetic division of M. To a flokkulonodulyarny share there are preddverno-cerebellar fibers. Afferent ways of a paleotserebellum are presented front and back (dorsal) in the spinomozzhechkovy ways, fibers from thin and wedge-shaped kernels, sensitive kernels of cranial nerves, reticular and cerebellar and pokryshechno-cerebellar in the ways. In a neotserebelluma the fibers from kernels of the bridge, preferential opposite side making an end body cortical mosto - a cerebellar way, and olivocerebellar fibers terminate (tsvetn. fig. 1). There are data on feedforwards of M. with all cranial nerves.
Efferent fibers of bark M. are axons of pear-shaped neurocytes. Fibers from a medial zone of bark and a scrap go to a kernel of a tent and predoor kernels (hl. obr. to lateral), from an intermediate zone of bark — to cork and spherical kernels, from lateral departments — to a gear kernel.
Fibers to the kernels of a brain trunk included in motive ways originate from M.'s kernels (see. Motoriums, ways ). The ascending efferent fibers go from a gear kernel to the ventrolateralny kernels of a thalamus transferring impulses in a motive zone of bark of a great brain; from a cork kernel — to the central kernels of a thalamus connected with a striate body.
The majority of efferent pathways passes in upper cerebellar legs and forms decussation in a tire of a mesencephalon (decussatio pedunculorum cerebellarium sup.).
History of studying of functions of a cerebellum
the Early researches on M.'s physiology conducted in 18 — 19 centuries did not allow to draw certain conclusions on its functions. The first serious experimental studying of M. was undertaken by Rolando (L. Rolando, 1809). Damaging or deleting M. at various animals, he paid attention to disturbance at them of autokinesias and established M.'s connection with Goma lateral parts of a body. These observations were continued by M. Flurans (1830), to-ry put forward the concept about regulatory influence of M. on motor activity. It for the first time noted the high extent of compensation coming after partial removal of a cerebellum. F. Marangdi (1824) on the basis of experiments on section of legs of M. considered it as the center of nervous mechanisms of balance. The new period in studying of functions M. begins with L. Luchani (1891) works, Krom managed to watch animals after M.'s removal for a long time and to make the careful analysis of symptoms of a cerebellar shortcoming. It for the first time created the reasonable theory about functions M. which gained in due time wide recognition. Researches L. Luchani was shown that the main complex of motive disturbances of a cerebellar origin is the cerebellar ataxy including such symptoms as an atony, an astasia and an adynamy (Luchani's triad). According to L. Luchani, M. is the subsidiary body of a brain in coordination of operation of the motive device; it exerts the regulating impact on formations of c. N page and peripheral neuromuscular system by tonic, static and trophic actions. L. Luchani's researches showed active participation of bark of big hemispheres, in particular to its sensomotor area, in compensations of motor cerebellar frustration (functional compensation), and also a possibility of substitution of the defects of the movement caused by partial removal of M., the remained its sites (organic compensation). Thus, in 19 century three main directions in the doctrine about M. Ideya Rolando about diffusion cerebellar influence on all motor activity were created engendered L. Luchani's hypothesis of the tonic facilitating M.'s influence on the central structures controlling activity of skeletal muscles. M. Flurans's concept about M.'s communication with coordination of movements was supported and improved Lyussana (F. Lussana, 1862) and M. Lewandowski (1903), to-rye tried to correlate functions M. with a myesthesia. F. Marangdi's hypothesis found the further development in Ferrier's works (D. Ferrier, 1876), Stephanie (A. Stefani, 1877), V. M. Bekhtereva (1884) and Toma (A. Thomas, 1897); in them M. is considered as the organ of equilibrium which is closely tied with the vestibulyatorny device. All listed researches were executed by method of removal of M. At the end of 19 century Ch. Sherrington (1897), Levental and Horsley (M. of Lowenthal, V. And. H. Horsley, 1897) it was almost at the same time revealed that cerebrate rigidity (see) it can be slowed down by irritation of M.
This observation was the beginning of the new line of the neurophysiological researches which revealed existence of close ties of M. with all systems of supraspinal control. In the subsequent the combination of these two methods of experimental studying led to a conclusion about a special role of M. in the course of motive management, and a wedge, observations, having confirmed preferential motive orientation of cerebellar symptomatology, found a community in a picture of defeat of M. in the person and animals. V. M. Bekhterev (1905) considered M. complex body of regulation of motor and touch activity of an organism, including its highest nervous functions. L. A. Orbeli (1938, 1940) and his employees was nominated essentially new point of view about functions M. Their numerous researches showed existence close funkts, bonds between M. and autonomic nervous system (see). The m was considered as body of adaptation and trophic influence, as the universal modulator of reflex activity of an organism controlling its various vegetative and afferent functions along with the motive device. In the next years many mechanisms of this modulating M.'s influence
Participation of a cerebellum in regulation of functions of an organism
by the Most accurate manifestation of switching off of functions of a cerebellum were found out from animals and the person disturbances of motive activity are. At the same time first of all frustration of a tone is noted (see).
Removal of a cerebellum causes a hypertension of ex-tensor muscles of extremities in dogs and cats and opisthotonos (see) owing to what the animal cannot stand. In several days of the phenomenon of an ex-tensor tone weaken and are replaced by hypotonia. At primacies, and also at the person of defeat of M. lead to decrease in a muscle tone at once. At the lowest mammals emergence of an ex-tensor hyper tone is connected with release of myostatic and labyrinth reflexes, and also a reticular formation from tonic braking M.'s influence; at primacies hypotonia of muscles results from elimination of tonic facilitating M.'s influence on talamokorkovy systems. Other origins of an atony are that the ex-tensor motor-neurons of a spinal cord deprived of the facilitating influence from a kernel of a tent of M. are easier braked under the influence of crossed proprioceptive reflexes. The atony of muscles is promoted also by paralysis of gamma and efferent system. The adynamy — decrease in force of muscular contraction, and also an astasia — loss of ability to long reduction of muscles has close connection with the phenomena of an atony. At patients with hemilesion of M. decrease approximately twice in force developed by muscles on the sick party in comparison with muscles of the healthy party is noted. Other characteristic manifestation of disturbance of functions M. is the tremor (see. Trembling ) — oscillating motions, to-rye arise at rest at a certain degree of muscular tension (a static tremor) and at implementation of the motive act (a kinetic, atactic or intentsionny tremor). Contagious or motive excitation strengthens a tremor. At patients the intentsionny tremor happens to M.'s defeats especially expressed at the beginning or at the end of the movement and also when the patient changes the direction of the movement. It is shown that the tremor at cats without cerebellum disappears after a decortication, and at monkeys — after removal of pretsentralny motor bark. Disturbance of functions M. is shown in loss of smoothness and stability of movements, force, size, speed of movements is broken: they become discontinuous and tolchkoobrazny, their rhythm is broken. Delay of reduction and relaxation of muscles is observed, the sudden termination of the movement is complicated. These phenomena ataxy (see) clearly are found in characteristic disorder of gait, edges becomes clumsy at widely placed extremities, with signs of a dismetriya — disorders of dimension of the made movement. Sharply the speed of change of the direction of the movement decreases (adiadokhokinez). Also the lack of coordination of movements is observed that depends on disorder of normal interaction of the centers which are taking part in performance of the movement (asynergia). Removal or M.'s irritation leads to the shifts breaking also the course of vegetative processes and causing frustration of a number of functions of an organism. Studying of a role of M. in regulation of activity of a digestive tract, cardiovascular system, breath, thermal control, a hemopoiesis, metabolism etc. found out that it of M. thanks to the double mechanism of action (oppressing and stimulating) exerts the stabilizing impact on the listed functions. M.'s role in a korrigirovaniye of visceromotor reflexes is shown. M.'s communication with the highest vegetative centers and with nek-ry hemadens allows to consider it as the body connected with regulatory mechanisms of century of N of page. In turn funkts, M.'s condition is under the influence of a vegetative innervation. Cellular elements of bark M have data on existence of intra secretory function. At M.'s defeats increase in range of fluctuations of threshold sizes (skin, temperature, visual sensitivity, assessment of weight of the lifted subject) is noted. Success in a research of mechanisms of influence of M. on proprioceptive sensitivity is achieved. Features of regulation of M. of the afferent category of muscle spindles are shown, its role in activity alpha and gamma motor-neurons is revealed at implementation of the motive act.
The functional organization of a cerebellum (localization of functions in a cerebellum)
M.'s bark differs in a peculiar organization of interneural bonds (fig. 6) and extraordinary development of brake synoptic mechanisms that causes special operational characteristics of this education and distinguishes it from other departments of c. N of page. From five types of neurons of bark M. four the only efferent neurons — pear-shaped neurocytes (Purkinye's cell) are brake, including and. All afferent information reaches bark M. on two systems anatomically of the isolated entrances, to-rye terminate in the form of lianoid and mossy fibers. The system of lianoid fibers represents a monosinaptichesky entrance, to-ry comes into direct contact to Purkinye's cells and his dendrites. The course of branching of lianoid fiber almost repeats a picture of branching of a dendritic tree of a cell of Purkinye up to his final branchings. Lianoid fiber comes into a set of synoptic contacts with dendrites of a cell of Purkinye by means of their spinules that creates a big synoptic surface. It is the main premises of exclusively strong synoptic exciting action of an input of lianoid fiber, a cut by the efficiency in c. the N of page of the highest animals treats the most considerable. Lianoid fibers originate from the lower olivariy kernel of a myelencephalon. Mossy fibers form difficult synoptic connections of glomerular type with dendrites of small granular neurocytes. Axons of the last ascend in a molecular layer, T-shapedly are divided into parallel fibers, to-rye come into synoptic contacts with dendrites of cells of Purkinye. Besides, parallel fibers form multiple exciting synapses with a dendritic tree of star-shaped, korzinchaty cells and big granular neurocytes (Golgi's cells). The first two types of nervous cells have brake effect on Purkinye's cells, Golgi's cells brake small granular neurocytes. Thus, the input of mossy fibers unlike lianoid has the mixed, vozbuditelnotormozny effect on key elements of bark M. — Purkinye's cell. It creates two braking mechanisms located one above another in bark M. Mossy fibers originate from many departments of c. N of page (front and back spinomozzhechkovy ways, kernels of the bridge, reticular formation, vestibular nuclei, etc.). These two afferent entrances are characterized by various spatio-temporal distribution in bark M. They differ also in quantitative and funkts, the relation: each cell of Purkinye receives impulses approximately from 100 000 parallel fibers and only one lianoid fiber. However one lianoid fiber has very powerful exciting effect on Purkinye's cell while extensive convergence of impulses of many mossy fibers for generation of the category of a cell of Purkinye is required. Despite differences, both systems of afferent fibers supply bark M. substantially with the same information from the periphery and a cerebral cortex. At the same time thanks to features of neural bonds of M. the exciting signal coming to bark M. via both afferent channels at most through two synoptic switchings can be transformed to brake. Therefore not the mechanism of start of the subsequent neuron in a reflex chain, and the mechanism of its braking speaks at escaping of bark M. as an effective agent. This feature leaves the mark on a design of efferent system M. Its first two links are in a state funkts, antagonism: to brake influence of cells of Purkinye it is opposed the tonic excitement of neurons of kernels of M. which is generally caused by activation of collaterals of lianoid and mossy fibers. The last play the leading role as the frequency of their background activity is much higher, than in lianoid fibers. M.'s bark, like a cerebral cortex, perceives almost all types of afferent signals. Their distribution in bark M. is characterized by a certain topography depending on a modality of an afferent flow. In the structurally functional relation of M. is divided into three shares (lobulyarny topography): ancient M. (arkhitserebellum), old M. (paleotserebellum) and new formation of M. (neotserebellum). Arkhitserebellum who is generally covering a flokullonodulyarny share represents vestibular department of M. V it primary vestibular afferent fibers and fibers from vestibular nuclei terminate. At defeat of this area disturbance of balance is observed (see Balance of a body). Paleotserebellum is presented by a front share, a simple segment and the tail of a body of a cerebellum. Afferent fibers in paleotserebellum arrive preferential from a spinal cord and sensomotor area of a cerebral cortex. The terminations of spinomozzhechkovy and kortiko-cerebellar ways in an intermediate zone of a front share and in a paramedian segment of M. (a homolog of lobulus gracilis) of the person, edge were allocated between the lower semi-lunar and biventral segments earlier, have the accurate somatotopichesky organization. The strict somatotopichnost is characteristic also of efferent influences of a paleotserebellum. Neotserebellum includes a middle part of a body and the most part of hemispheres of M. He receives signals generally from a cerebral cortex, and also from acoustical and visual receptors. Being evolutionarily the youngest department of M., neotserebellum plays the leading role in mechanisms of cerebellar and cortical relationship. Along with M.'s division according to cross furrows into shares localization of various functions in M. is noted also in the mediolateral direction at its longitudinal division into three symmetric cortical and nuclear zones (cortical and nuclear topography): the medial (worm), projected on a medial kernel M. (a kernel of a tent) and a lateral vestibular nucleus (bridge of a brain); the intermediate (okolochervyachny), projected on an intermediate kernel M. (homolog of cork and spherical kernels of M. of the person), and lateral zone, projections a cut go to a lateral (gear) kernel. M.'s kernels, in turn, are projected on different structures of a brain, and than lateralny the kernel is located, to more high levels of a brain it sends those the fibers. By physiological experiments it is shown that the medial zone M. is connected with regulation of a tone, locomotions and balances of all body; the intermediate zone M. regulates the movement, situation and a tone only of ipsilateralny extremities; the lateral zone M. carries out regulation of thin movements of ipsilateralny extremities. Thus, each longitudinal zone works as the coordinator for a certain type of the motor act. Lobulyarny and cortical and nuclear topography are based respectively on the organization of afferent and efferent systems M. They mutually supplement each other, reflecting complexity funkts, localizations in M.
Close connection between M. and a cerebral cortex represents one of most idiosyncrasies of activity of M. Development of these two structures in phylogenesis happens in parallel and is followed by improvement of composite motor reactions. All three kernels of M. exert impact on a cerebral cortex, however effects of lateral neomozzhechko-vy areas are dominating. As relay formations of ascending M.'s influences serve specific and nonspecific kernels thalamus (see), and also pontomedullyarny reticular formation (see). The kernels of a thalamus transmitting cerebellar and cortical signals respectively to sensomotor and associative areas of a cerebral cortex are distinguished from them ventrolateralny and ventral front. By electrophysiologic researches it is shown that fastigiokorkovy influences are characterized by diffusion and bilateralnostyo whereas effects intermediate (cork and spherical) and gear M.'s kernels are topographical limited and preferential contralateral. The cerebral cortex exerts reciprocal impact on structures of M. The main relay educations for transfer of cortical signals to M. are kernels of the bridge, the lower olive and a lateral reticular kernel.
According to modern representations the intermediate zone of a front share of M. exercises the dynamic motive control directed to comparison and correction of a programmable and current status of the peripheral device. Purkinye's cells of this zone integrate the cortical and peripheral entrances representing one extremity and transmit the resulting signals on systems of the descending and ascending feed-backs. Cortical signals reach M. of the spinal signals informing on results of action of the previous motor team much earlier. Comparison of teams from motor bark of rather following phase of the movement with peripheral information on the developed movement allows M. to make necessary amendments and on the course to improve the current physical activity, bringing it into accord with a real situation thanks to the adjusting parcels to motor bark and to motor-neurons of a spinal cord. As M.'s influences on motor-neurons of a spinal cord can be carried out in the bystry descending ways, the begun movement is modified already at early stages of the development.
M.'s hemispheres carry out correction of the planned, prepared movement at the moment when it shall begin. This ability of lateral departments of M. has a structural basis in the form of wide bilateral projections to associative and sensomotor bark. M.'s hemispheres, being one of ways of information transfer from associative bark to motor bark, participate in processes of initiation of a physical activity. By electrophysiologic researches on animals it is shown that change of activity of neurons of M. precedes the movement.
At implementation of motive acts the category of neurons of M. advances the category of neurons of a ventrolateralny kernel of a thalamus and motor bark in time a little. During the cooling of kernels of M. the delay of activity of neurons of pretsentralny areas and a start of motion is observed. These facts will be coordinated about a wedge, observations about a delay of a call of movements at patients with damages M. Predpolagayut that M.'s participation in advance planning of movements is substantially based on training and the previous experience; during life of an animal and the person so-called training of M. as the education involved in unusually complex system of the organization and control of movements is continuously carried out.
Recognition for M. of ability of training and function of some kind of computer is one of the most important results of a research of mechanisms of activity of M. Along with a number structural and funkts, M.'s features it is property is defined by existence of an upgradeable synapse on Purkinye's cell. According to the existing hypothetical representations coincidence of activity of lianoid fiber to activity in parallel fibers results plastic changes in synapses of parallel fibers that is explained by trophic action of a lianoid afferent entrance on dendrites of cells of Purkinye. During process of training the cerebral cortex sends consecutive instructions for the movement, to-rye reach Purkinye's cells. Thanks to learning of a certain context of the touch information connected with implementation of the relevant movement, Purkinye's cell studies to answer the isolated signal arriving only on parallel fibers. Thus, the excited Purkinye's cell starts the sequence of elementary movements.
METHODS of the RESEARCH
For diagnosis of defeats of M. use the same methods, as at a research of a brain in general (see. Brain, methods of a research ).
Clinical methods. The anamnesis, the general survey of the patient, a research of movements, gait, conducting tests and identification of the symptoms characteristic of M.
Primenyayutsya's defeat concern to them spinal puncture (see) and suboktsipitalny puncture (see) with a research cerebrospinal liquid (see), kraniografiya (see), ventrikulografiya (see), vertebralny angiography (see), a computer tomography of a brain (see. Tomography computer ). Are important ekhoentsefalografiya (see), electroencephalography (see) and rheoencephalography (see). Apply to a research of disturbances of gait plantografiya (see) and an ikhnografiya — a method of a research of gait, and also a form of feet on their prints received during the walking according to the sheet of paper imposed on the metallic stripe coated.
Physiological methods (in an experiment). The main methods of studying of functions M. — its extirpation, electric irritation, registration of electric activity of M., evoked potentials (the potentials observed in M. in response to the irritations applied on any central formations of a brain, esodic nerves or receptor fields of an organism). Are of great importance a stereotaxic method of a research (see. Stereotaxic method ), Microelectrode method of a research (see) extracellular and intracellular bioelectric activity of separate neurons.
At patol, the processes which are followed by a hypoxia (disturbances of cerebral circulation, epilepsy, inf. diseases, etc.), are observed a chromatolysis (see. Nervous cell ), a hyperchromatosis (see. Kernel of a cell ), cytolysis (see), the homogenizing change of neurons of a gear kernel (fig. 7), ischemic change (fig. 8) and loss of the pear-shaped neurocytes especially sensitive to a lack of oxygen.
In a molecular layer of bark of the died on the spot dendrites of pear-shaped neurocytes accumulations of gliotsit — a so-called kustovidny glia quite often are found, and death of pear-shaped neurocytes is followed by proliferation of lofogliotsit (fig. 9), shoots to-rykh at massive losses of neurocytes (e.g., near heart attacks) give striation to a molecular layer. Death of neurons of a gear kernel is also followed by isomorphic gliosis (see). At a number of diseases the so-called transneyronalny (transsinaptichesky) degeneration of neurons (e.g., neurons of a gear kernel develops in M. at losses of pear-shaped neurocytes).
At increase in intracranial pressure (at wet brain, tumors, hemorrhages in a cerebellum) the necrosis of separate granular neurocytes, their groups or all granular layer of bark (fig. 10) is often observed.
At wet brain (see. Swelled also swelling of a brain ), followed by the axial shift of its trunk, on a lower surface of M. strangulyatsionny furrows — a trace of pressure of edge of a big occipital opening are formed. The parts of a lower surface of M. displaced in an occipital opening form a cerebellar cone of pressure (see. Dislocation of a brain ). At patol, the processes which are followed by increase in volume of M. on its dorsal surface the gage relief of pressure sometimes forms (implementation of dorsal departments of a worm and hemispheres of a cerebellum in an opening of a tent of a cerebellum).
Heart attacks develop in M. at fibrinferments, stenoses and embolisms cerebellar, vertebral and basilar arteries. At obstruction of an upper cerebellar artery heart attack (see) arises, as a rule, in quadrangular and upper semi-lunar M.'s segments and a mesencephalon; at obstruction of a front lower cerebellar artery — in side departments of hemispheres of M. and caudal department of a tire of the bridge; at obstruction of a back lower cerebellar artery — in the lower semi-lunar, biventral segments, an almond and in retroolivarny area of a myelencephalon. The sizes and localization of heart attacks in pools of arteries of M. are very variable and conditions of a collateral blood-groove and other factors depend on the sizes of the pool of these arteries. The heart attacks developing at stenoses of vertebral arteries proksimalny or at the level of the mouth of a back lower cerebellar artery are localized in zadnenizhny department of a hemisphere of M. (in a zone of adjacent blood supply back lower, front lower and upper cerebellar arteries), on side of a stenosed vertebral artery (fig. 11). They have the cone-shaped form with the top directed to a surface of a hemisphere. From M.'s surface such heart attacks are not visible. For detection they should be done cuts (fig. 12) in the sagittal plane (through a worm — in strictly sagittal, through hemispheres — at an angle in 30 ° and 60 ° to the median plane). Development of heart attacks of M. can be caused also by a prelum of his back lower artery in the field of a strangulyatsionny furrow on a lower surface of a hemisphere of M. at wet brain.
Hemorrhages are observed at ruptures of aneurisms, at angiomas, a craniocereberal injury, and also at hemorrhagic diathesis, leukoses and other diseases. Most often hemorrhages (like a hematoma) develop in M. at arterial hypertension in combination with atherosclerosis (see. Stroke ). The most probable mechanism of their development is the rupture of vessels, as a rule, of branches of an upper cerebellar artery. Preferential localization of hemorrhages — area of gear kernels and the central white matter of hemispheres. Development of intracranial hypertensia, occlusal hydrocephaly with the phenomena of dislocation of a cerebellum and a brainstem is characteristic of them, a prelum of substance of a brain and vessels at the level of an opening it is mashed a cerebellum and a big occipital opening with emergence of hypoxemic and necrobiotic changes of pear-shaped neurocytes and neurons of a gear kernel, necrosis of a granular layer of bark. Hemorrhages in M. often are followed by break of blood in the fourth ventricle and subarachnoid space.
Cases of a single single-chamber echinococcus of a cerebellum and multiple cysts of an echinococcus of hemicerebrums and M are described. In the presence of multiple tsistitserok of a brain they can be also located in covers, bark or white matter M. Localization of a single bubble of a cysticercus or echinococcus in a cavity of the fourth ventricle is possible.
Tuberculomas of a cerebellum happen single and multiple (see. Tuberculoma ), are localized in a grub and hemispheres, are sometimes combined with a tuberculoma of the bridge, a myelencephalon.
Atrophies of a cerebellum can be isolated or one of displays of more widespread diseases of a brain. They can develop at exogenous influences, to be inborn or hereditary, primary or secondary (at defeat of a great brain). Inborn atrophies are characterized by considerable reduction of M. in a size, losses of neurons, secondary change of white matter, proliferation of a glia. Distinguish several forms depending on involvement in process of all body or its certain departments from primary atrophies of M.
The atrophy of bark M. can be two types: a) with defeat of all layers of bark, at Krom there is primary death of pear-shaped neurocytes to their axons, reduction of a molecular layer, defeat of a granular layer of bark M.; b) with defeat only of a granular layer of bark when the minimum loss of pear-shaped neurocytes is noted, their heterotopy (it is quite often combined mentally retarded). The expressed atrophy of bark M. is found at a hereditary cerebellar ataxy (a syndrome, or a disease, Mari), to a lesser extent it is expressed at a family ataxy (Fridreykh's disease). Distinguish a syndrome, or a disease from so-called late atrophies of bark M., to Mari — Fua — Alazhuanina, for to-rogo preferential defeat of a worm with an atrophy of crinkles, a gaping of furrows of its dorsal departments and adjacent departments of hemispheres of M is characteristic. The late acquired atrophy of bark M. can be limited or extend to all bark M. It is histologically characterized by lack of nervous cells and an intensive gliosis. It is observed at infections, intoxications, alcoholism, tumors, an anoxia, a hyperthermia, meningoentsefalita of various etiology.
Cerebellar olivarnaya the atrophy (like Holmes) is a hereditary progressing degeneration of bark M. with a degeneration of neurons of the lower olives and sometimes with changes in tserebellyarny efferent pathways. Nek-ry morphologists consider cerebellar olivarnuyu an atrophy a prestage of an olivomostomozzhechkovy atrophy, for a cut primary atrophy of white matter M., system of fibers of foundation of the bridge of a brain with defeat of neurons of the lower olives of a myelencephalon, own kernels of the bridge is characteristic. M.'s bark at the same time is involved in process later owing to defeat of olivocerebellar and mostomozzhechkovy ways (a transsinaptichesky degeneration). Demyelination of white matter with a gliosis extends to average and lower legs of a cerebellum; changes are found also in a gear kernel. The Olivomostomozzhechkovy atrophy with changes in a spinal cord is observed at Giyen's syndrome (the progressing cerebellar syndrome with a tendinous areflexia).
Primary atrophy of kernels of M. is extremely rare, however an atrophy of kernels of M., generally gear, often meets at atrophies of bark M., the deforming muscular dystonia, a myoclonus epilepsy, and also at such rare diseases as the olivorubromozzhechkovy atrophy described by Lezhonn (M. M. R. of Lejonne) and Zh. Lermittom, a dentatorubralny atrophy, etc.
Secondary cross atrophies of M. can develop at extensive defects of bark of big cerebral hemispheres, especially if damage arises during formation of a nervous system or at later age owing to hemorrhage, a heart attack, an injury. At the same time in bark M. partial loss of pear-shaped neurocytes, reduction of a layer of granular neurocytes is observed, but defeat does not reach such degree, as at primary atrophies of bark M. Also reduction of quantity of nervous cells in a gear kernel, a reduction of white matter is observed. M.'s atrophy is, as a rule, combined with an atrophy of the relevant departments of the lower olives.
Cerebellar ataxy — the disturbance of movements in the form of disorder of their coordination caused by M.'s defeat and (or) its conduction paths; it is characterized by the fact that it is difficult for patient to keep balance, it shakes here and there, reminding drunk. Develops at the kept deep sensitivity. Ataxy (see) can be dynamic — at autokinesias of extremities, especially upper, and static — during the standing, walking.
Tests on identification of a dynamic ataxy the following. Calcaneal and knee test: to the patient lying on spin blindly suggest to raise highly a leg and a heel to get into a knee of other leg — the patient misses-legged that party where there is a center of defeat in area of a hemisphere of M., during the carrying out the leg on a front surface of a shin down to foot notes sliding of a heel in one, in other party.
Calcaneal and fist test: under a heel of the patient lying on spin, the doctor holds up the fist and suggests the patient to raise a leg, and then to lower it on a fist of the doctor — at the same time the ataxy comes to light.
Paltsenosovy test: the patient is offered to get slowly an index finger to a tip of a nose, previously having taken away a hand — it carries by a hand further the purpose, i.e. the gipermetriya is noted; besides, the intentsionny tremor amplifying in process of approach of a finger to a nose is noted.
Finger-finger test: it is offered to the patient at first with open, and then to get blindly to tips of index fingers of investigating — at the same time the promakhivaniye on the party of defeat is noted.
Tests on identification of a static ataxy the following. Pay attention to stability of the patient. The patient reels here and there, reminding drunk, the deviation is noted preferential towards the struck hemisphere of M. At defeat of a worm of the patient reels in one, in other party, widely placing legs; instability is especially noticeable at turns. At M.'s defeat the trunk can be straightened, «as a column», there are no usual consensual movements of hands during the walking. Conducts sya also a research of the patient in a pose Romberg: to the patient suggest to stand, having closed eyes and having extended hands forward, having densely shifted feet so that both heels and socks were together — the patient nadat towards the struck M.'s hemisphere, and at defeat of a worm M. falling can be in any party, and also back or forward. The sensibilized pose of Romberg is used when the poshatyvaniye comes to light insufficiently accurately: at the same time to the patient suggest to stand, having closed eyes, having extended hands forward, and to put legs on one line — one ahead of another. The result is estimated the same as at a research in a usual pose of Romberg.
Syndrome of an astasia — an abasia (an astasia — impossibility to stand, an abasia — impossibility to go) points to disturbance of difficult statokinetic functions that can be a consequence of disturbance of bonds of M. with bark of a great brain. At the same time at the patient in lying situation the active movements of the lower extremities are sufficient, there is no paresis.
Hyperkinesias at patients with M.'s defeat can arise owing to defeat of bonds of gear and red kernels (see Hyperkinesias), the choreoathetosis in extremities on the party of the center is noted, to-ry it is combined with lacks of coordination. At defeat of the lower olive and its bonds with a gear kernel myoclonias of language, a throat, a soft palate are observed. Synchronously with myoclonic fluctuations of a palatine velum and language there can be fluctuations of eyeglobes (a vertical and rotatorny nystagmus) that was described by G. Marinesku at the patient with hemorrhage in a gear kernel, a chetverokholmiya, a central route of a tire with defeat of olives. Unilateral myoclonias of a soft palate can be caused by defeat of a pokryshechno-spinal way (tractus tectospinalis) of the opposite side, a gear kernel of the same party or defeat of an olivocerebellar way. There is an opinion that at defeat of the lower olive there are rhythmic myoclonias, and at defeat of a gear kernel — an unrhythmical myoclonic hyperkinesia. Velopalatinnye myoclonias (see) can be combined with a hemiparesis and a gemigipesteziya on the party opposite to defeat. The combination of myoclonias to an intentsionny tremor, a nystagmus, a dismetriya, adiadokhokinezy, can be observed by hypotonia of muscles and epileptic seizures.
The tone of muscles of extremities at M.'s defeat decreases (hypotonia) or is absent (atony) on the party of defeat. At a research of passive movements flabbiness, slackness of muscles, overextension in joints, excess excursions in them is noted.
Pendulum reflexes can come to light: the patient is asked to sit down on the table edge of a pla of a bed thus that legs hanged down freely, and cause knee jerks — the shin of the patient makes several kachatelny movements. The research of cervical tonic reflexes of Magnus — Klein — reflexes of a position and straightening — reveals their absence at M.'s damage. Often so-called magnetic reaction comes to light: at a light touch to foot, especially to the bottom surface of a thumb, the movement of a pandiculation of all extremity appears.
Asynergia — disturbance of consensual activity of muscles during the performance of movements. During the conducting test on Babinsky's asynergia in a standing position to the patient suggest to cave in back, having thrown back at the same time the head; the patient with M.'s defeat, losing balance, falls due to the lack of consensual bending of legs (fig. 13) back; the healthy person has a consensual bending in knee and extension in hip joints (fig. 14). Babinsky's asynergia in a prone position comes to light as follows: to the patient lying on spin suggest to cross hands on a breast and to sit down — at cerebellar defeat of the patient cannot fix legs and a basin to the area of a support (legs rise up) and he does not manage to sit down (fig. 15); the healthy person has a consensual reduction of gluteuses, muscles of a prelum abdominale and it sits down (fig. 16). During the walking of the patient rearranges legs forward, and the trunk at the same time lags behind (fig. 17). The patient is not able to rise from a chair since legs at the same time are insufficiently bent in knees; at a look up the head synergistically is not thrown back, is absent also namorshchivany a forehead, at strong handshake there is no synergistic extension in a radiocarpal joint.
Adiadokhokinez find, suggesting the patient to extend hands forward and to alternately make pronation and supination of brushes. At M.'s defeat delay of change of opposite movements on the party of defeat is noted.
Dismetriya, in particular the gipermetriya, movements can be found as follows: the patient is offered to hold hands with the palms extended forward with divorced fingers up, then to sharply turn palms down — on the party of cerebellar frustration this movement is made with excess rotation of a brush (fig. 18). At identification of a symptom of Ozhekhovsky investigating suddenly takes away the palms, on to-rye investigated strong leans — the healthy person at the same time remains motionless or slightly deviates back, the patient with M.'s defeat sharply bends forward.
The speech at patients with M.'s defeat stretched, slowed down, often chanted: the patient pronounces words hardly, dividing them into syllables, with a pause between words and syllables, doing accents on each syllable. The scanning speech is caused by an articulation ataxy, disturbance of accurate consensual activity of muscles of the speech motor device (see. Dysarthtia ).
Also following symptoms are characteristic of M.'s defeat.
Stewart's symptom — Holmes: investigating suggests the patient to fix the supinated halfbent forearm and tries to unbend it, and then quickly takes away the hand — the hand of the patient with a force hits it in a breast since the patient cannot brake the movement of the hand in time.
Thomas's symptom — Zhyumanti (a symptom of a hvataniye) comes to light as follows: to the patient suggest to take a subject a hand — already at the beginning of a hvataniye it disproportionately widely opens a palm.
Thomas's symptoms: 1) if to push the patient standing sideways, then it will cause a raising of a leg on the party of influence and falling to the opposite side; 2) to the patient lying on spin, investigating several times takes away and gives a knee, and then lowers — on the party of defeat the extremity inertly falls in the provision of rotation of a knaruzha; 3) in a standing position to the patient suggest to bend aside — at an inclination in the healthy party there is an increase in a tone of razgibately this party and assignment of the lower extremity of the opposite side, and at an inclination towards the center does not occur either gomolateralny increase in a tone of razgibatel, or assignment of the lower extremity of the opposite side; 4) «rigidity of tension» meets preferential at defeats of a worm — the patient moves as a column owing to a muscle tension of a trunk.
Symptom of Fua — Tevenara: the small push causes tension of razgibatel of the lower extremities and muscles of a stomach in the healthy person back, the push causes tension of sgibatel forward, the patient with cerebellar defeat at these tests easily loses balance.
It is possible to differentiate separate signs, pathognomonic it is preferential for defeat of a worm, hemispheres and legs of a cerebellum. So, the preferential ataxy of a trunk, disturbance of a statics, falling of the patient forward or back, an ataxy are characteristic of defeat of a worm during the walking; defeat of hemispheres of a cerebellum leads to change of performance of locomotory tests (paltsenosovy, calcaneal and knee), to an intentsionny tremor in extremities on the party of defeat, hypotonia. Damage of legs of M. is followed by development a wedge, the symptoms caused by damage of the corresponding bonds. At damage of the lower legs are sometimes observed nystagmus (see), myoclonias of a soft palate; at damage of average legs — disturbance of locomotory tests; at damage of upper legs — emergence of a choreoathetosis, rubralny tremor (see. Trembling ).
Cerebellar frustration at syndromes of a mostomozzhechkovy corner and cerebellar it is mashed. Syndrome mostomozzhechkovy corner (see) usually arises at a tumor VIII or VII cranial nerves. VIII, VII cranial nerves with involvement in process of V, sometimes the VI nerves are shown by symptoms of defeat; Goma a lateral ataxy and a cross hemiparesis of extremities is characteristic.
A syndrome of cerebellar it is mashed (see. Tentorial syndrome ) develops at an arakhnoidendotelioma it is mashed a cerebellum. The expressed gipertenzionny syndrome, and also pains in a zone of an innervation of the V cranial nerve, in eye-sockets, a back surface of eyes, a nose bridge, malars is characteristic; pains are quite often combined with a photophobia and dacryagogue. Pains irradiate in a nape, a neck, sometimes to the interscapular area, a hand.
In process of increase in a tumor depending on the preferential direction of its growth — in a back cranial pole or to the supratentorial area — also other symptoms can appear. So, with a growth of a tumor in a back cranial pole defeat of VI and VII, sometimes the VIII cranial nerves is quite often observed (noise in an ear, a rotatory vertigo). Cerebellar symptoms appear late and can be expressed minimum. Soft expressiveness, late emergence of cerebellar symptomatology are explained by M.'s adaptation at slowly growing tumor. At the same time statokinetic frustration come earlier and are expressed more sharply, than koordinatorny disturbances that is connected with proximity of an arrangement of a tumor to the centerline and defeat of a worm of a cerebellum.
With a growth of a tumor to the supratentorial area symptoms of impact on parencephalons appear: a visual disturbance in the form of loss of fields of vision, visual hallucinations, photopsias, sometimes a blindness. Disturbances of sensitivity on extremities, anamnestic disturbances of the speech, a hemiparesis can be observed. Symptoms of damage of upper parts of a trunk as well as caudal part it, at tumors of cerebellar it is mashed appear in late stages and are caused by the dislocation phenomena.
on the basis of Mackey and Bentivolyo's topografo-ontogenetic criteria (G. Macchi, M. of Bentivoglio) allocate total and subtotal (lateral and median) an agenesia. Total M.'s agenesias meets seldom, it is combined with other heavy anomalies of development of a nervous system (an anencephalia, an amiyeliya). The subtotal agenesia which is combined with malformations of other departments of a brain is most often observed (an agenesia of the bridge, lack of the fourth ventricle, etc.). M.'s hypoplasias meet, as a rule, in two options: all M.'s reduction and a hypoplasia of separate parts M. with preservation of normal structure of its other departments. They can be one - and bilateral, and also lobar, lobulyarny and intrakortikalny. Allocate various changes of a configuration of leaves — an allogiriya, a makrogiriya, a polygyria, an agiriya.
Dizrafichesky disturbances are most often localized in the field of a worm and the lower brain sail and meet in shape to a tserebellogidromeningotsela or in the form of quite big slit-like defect.
The hypertrophy of molecular and granular layers of bark M. is followed by increase in its volume and meets at such malformation of a brain as a megaloentsefaliya (see. Makrotsefaliya ). Heterotopy of pear-shaped neurocytes can be combined with other malformations of M., and also be observed at healthy people.
Clinically malformations are shown by disorders of balance and lacks of coordination in extremities, to-rye in some cases arise against the background of more diffusion defeat of a nervous system. Are characteristic mental inferiority up to an idiocy and disturbance of development of motive functions.
Open damages of M. are observed at a cherepnomozgovy injury (see) along with damage of other formations of a back cranial pole also lead in most cases to death.
At the closed craniocereberal injuries the symptomatology of defeat of M. owing to a bruise directly in the field of its arrangement or as a result of antiblow quite often develops.
Especially often M. suffers during the falling on a back or a bruise of sheynozatylochny area. At the same time morbidity, a hyperemia, hypostasis and consolidation of soft tissues in cervicooccipital area is noted, and on kraniogramma the fracture of an occipital bone quite often is defined. Directly after M.'s injury there is an instability in Romberg's pose, a poshatyvaniye during the walking, uncertainty at purposive movements, adiadokhokinez, decrease in a muscle tone in extremities. Symptoms of defeat of M. are almost always combined with symptoms of defeat of a brainstem, to-rye can arise not only owing to a bruise, but also owing to formation acute, subacute or chronic Epi - or a subdural hematoma of a back cranial pole.
Hematomas of a back cranial pole in comparison with konveksitalny hematomas, according to L. B. Likhterman and L. X. Hitrina (1973), meet seldom. More often they are, especially epidural, unilateral and arise owing to venous bleeding from a cross sine, veins of a firm cover, emissarny veins. Less often bleeding arises from cortical vessels of M. At the same time local pains in occipital area, the vomiting, dizziness amplifying at a postural change of the head and a pose, the fixed position of the head, Meningeal symptoms, especially a stiff neck are observed. Headaches can proceed as gipertenzionno-gidrotsefalny crises owing to occlusion of likvorny spaces at the level of the fourth ventricle and Marangdi's opening (see. Occlusal syndrome ). Cerebellar symptoms — disturbances of a statics and gait are characteristic, the ataxy in extremities, the most resistant is diffusion decrease in a tone of muscles of extremities. Cerebellar symptoms are noted on both sides, but prevail on the party of a hematoma. There are trunk symptoms — a spontaneous horizontal or multiple nystagmus, decrease in corneal reflexes, a bilateral Babinski's reflex. From cranial nerves VI and VII nerves suffer more often.
Hron, subdural hematomas in the area M. meet seldom. Klien, their picture is similar to a picture of a tumor of M. Odnako at M.'s tumors gipertenzionny symptoms are expressed more sharply, than at hron, hematomas, to-rye can proceed against the background of normal eyeground (see) and in the absence of changes on roentgenograms of a skull. For differential diagnosis also existence of an injury in the anamnesis matters.
At the isolated intra cerebellar hematomas it can be observed subacute and hron, the current, especially at children, at to-rykh an etiology of a hematoma sometimes remains not clear. All-brain symptoms accrue gradually, the wedge, signs of increase in intracranial pressure in the form of attacks of headaches and developments of stagnation on an eyeground appear. Symptoms of defeat of M. with more or less expressed dominance on one party, the fixed position of the head, dizziness, trunk symptoms — a spontaneous horizontal or multiple nystagmus, decrease in corneal and pharyngeal reflexes, disturbance of a railroad nystagmus, paresis of a look up, and also dysfunctions of cranial nerves at the level of a back cranial pole come to light. Klien, picture in these cases is very similar to that, edges is characteristic of a tumor of M.
Hemorrhages in M. at a cherepnomozgovy injury meet seldom. The wedge, a picture of hemorrhage in M. depends on the size of a hematoma, degree of a prelum and disturbance of blood circulation in a brainstem, existence of break of hemorrhage in the fourth ventricle and subarachnoid space, on character and weight of the accompanying injuries of a skull and brain.
At massive hemorrhage in one or both hemispheres of a cerebellum with break in the fourth ventricle and subarachnoid space of the patient faints at once, heavy coma, vomiting develops, sharp diffusion hypotonia, an areflexia, the floating movements of eyeglobes, lack of reaction of pupils to light, disorders of breath and cordial activity are noted. Quickly M.'s hypostasis and a brainstem leading to death accrues.
In rare instances at a cherepnomozgovy injury perhaps acute accumulation of cerebrospinal liquid in subdural spaces of a back cranial pole with formation of a gidroma which is followed by the progressing increase of a headache, repeated vomitings, emergence of the meeting squint, a nystagmus, a cerebellar ataxy, pyramidal symptoms.
Treatment of traumatic damages of M. corresponds to treatment of a craniocereberal injury (see).
Features of fighting injuries of a cerebellum and stage treatment — see. Craniocereberal injury .
Damages of a cerebellum of vascular genesis.
1. Wallenberg's syndrome — Zakharchenko (see. Alternating syndromes ) arises at fibrinferment of a vertebral artery at the level of an otkhozhdeniye of a back lower cerebellar artery as a result of a heart attack in a posterolateral part of a medulla and lower parts of a worm and a hemisphere M. Naiboley typical a wedge, manifestations more often: gomolateralno — segmented disorders of sensitivity on a face, Horner's syndrome (see. Bernard-Horner syndrome ), paralysis of a soft palate, throat, phonatory band, ataxy; kontralateralno — frustration painful and a thermoesthesia on extremities and a trunk, sometimes geminarez. Options a wedge, manifestations of this syndrome can be various.
2. The syndrome of obstruction of a front lower cerebellar artery results from ischemia of the zone supplied by this artery. The front bottom of a hemisphere of M., an average leg of M., a dorsal part of an upper part of a myelencephalon, the bottom of a tire of a varoliyev of the bridge and roots VII, VIII cranial nerves belongs to this zone.
Clinical manifestations: Goma a lateral and cerebellar ataxy, deafness, a flaccid paralysis of the VII nerve, loss painful, temperature, to a lesser extent tactile sensitivity on a face, Horner's syndrome; kontralateralno — a gemigipesteziya painful and a thermoesthesia on a body.
3. The syndrome of damage of an upper cerebellar artery results from ischemia of an upper part of a hemisphere and an upper part of a worm, upper and average cerebellar legs, a part of legs of a brain, the lower hillocks a chetverokholmiya, parts of a tire of the bridge. Wedge, manifestations: gomolateralno — an ataxy in extremities, the involuntary choreiform movements in them (or a tremor, myoclonias), Horner's syndrome; kontralateralno — decrease painful and a thermoesthesia (or all types of sensitivity).
4. Benedict's syndrome — the center of ischemia is localized in a leg of a brain with a softening in the field of a red kernel, a kernel of the III pair of cranial nerves, a medial loop. Wedge, manifestations: gomolateralno — paralysis of a third cranial nerve; kontralateralno — a lack of coordination of movements in extremities (or a choreiform hyperkinesia), a gemigipesteziya.
5. Mari's syndrome — Fua — the cerebellar frustration arising at defeat of a hemisphere of M. is frequent at disturbances of blood circulation; it is combined with a myoclonia of a soft palate, a pyramidal hemiparesis and a gemigipesteziya on the party opposite to the center of defeat.
6. At hemorrhages in M. unlike ischemic strokes (see) cerebellar symptomatology comes to light not always because of quite bystry development of a coma (see Côme, at diseases of a nervous system). Dominance of trunk symptoms is noted. The sudden beginning of a disease with vomiting, sharp pain in cervicooccipital area, bystry disturbance of cardiovascular and respiratory activity and other trunk disturbances, a low muscle tone in the absence of paresis of extremities, muscle tension of a nape is characteristic at absence or poorly expressed Kernig's sign (see. Kerniga symptom ).
At limited hemorrhages and the ischemic centers in M., especially at the beginning of a disease, cerebellar symptoms are found: intentsionny tremor and promakhivaniye, ataxy, etc. Often at disturbances of blood circulation in M. of hemorrhagic and ischemic character the expressed vegetative and trophic frustration are found: pallor and plentiful sweating on a face, delay of pulse, the changing coloring of skin, a mramornost, a cold snap of distal departments of extremities and a hyperhidrosis. Vegetative and trophic frustration depend, apparently, on disturbance of anatomo-physiological bonds with the centers of a hypothalamus; M.'s influences on a reticular formation of a brainstem matter probably and patol.
The psychopathological symptomatology is found in all patients with an acute disorder of blood circulation in M. even before development of a coma, edges consists in frustration of the affective and strong-willed sphere and the progressing changes of consciousness. The increased emotional instability, euphoria, noncriticality to the state can be noted. Strong-willed disturbances in the form of inadequacy of behavior, concern in a bed, disturbances, resistance to treatment proceed against the background of reduction of clarity of consciousness that it is shown by disorganization, inadequacy of statements, the ideas of self-accusation and self-abasement, slackness, passivity, bystry exhaustion of mental functions. Nek-ry clinical physicians explain development of these symptoms with simultaneous ischemia of a reticular formation of a brainstem and other its educations.
Treatment of defeats of M. of vascular genesis is carried out the same as at hemorrhagic and ischemic strokes of other localization (see. Stroke ).
Atrophy. The main a wedge, symptoms are the cerebellar frustration which are combined in some cases with signs of damage of other parts of the nervous system, in particular extrapyramidal department. Mari's disease — Fua — Alazhuanina is shown at patients of middle or advanced age with cerebellar symptomatology, edges tends to slow progressing. It is clinically shown by the progressing disturbances of a statics and gait, the nystagmus, a dysphagia, an alalia as a dysarthtia often comes to light. In later stages of a disease there is the general constraint, and still later there are impossible a standing and walking. The progressing akineziya dominates over koordinatorny disturbances. The akinetiko-rigid symptom complex develops. There are mental disorders.
Giyen's syndrome — the progressing cerebellar ataxy with the tendinous areflexia caused by olivopontotserebellyarny dystrophy and defeat of back cords of a spinal cord.
Also myoclonic cerebellar dyssynergia of Hunt — the progressing disease belongs to atrophic defeats of M., a cut it is characterized by an intentsionny tremor at first in hands, then in other parts of a body. Frequent symptoms of a disease are myoclonias, a nystagmus, a dismetriya, hypotonia of muscles, epileptic seizures. Symptomatic treatment. Abscesses of a cerebellum make 29% of all abscesses of a brain. The formations of the capsule, transition of a focal purulent inflammation to the encapsulated abscess given about terms are various. Most of specialists consider that the forming capsule is found in 1 — 2 week, and in 6 weeks it is completely created.
Abscesses M are localized more often in anterolateral departments of hemispheres (lower or upper semi-lunar segments, a quadrangular or biventral segment). They seldom go beyond one segment and hl are located. obr. in white matter at a depth of 1 — 2 cm. Have the small sizes, the round or oval form, sometimes in their walls karmanovidny cavities appear. Less often M.'s abscesses have platelet shape. Around the center of a purulent inflammation reaction of a glia is found, it is preferential in the form of its proliferation, and swelled, to-ry can be considerable and extend to all hemispheres of M. and even out of its limits.
Distinguish metastatic and contact abscesses of M. Metastatic abscesses meet seldom; they develop owing to or purulent diseases in a chest cavity (hron, an esophagitis, an empyema of a pleura, an inflammation, abscess of a lung, a septic endocarditis, a bronchoectatic disease), or pyoinflammatory processes of other localization, including also the remote body parts (e.g., abscess on foot, hron, osteomyelitis of tubular bones, etc.). At newborns and children of chest age metastatic abscess of M. can arise owing to umbilical sepsis, pustulous diseases of skin, inborn heart disease.
Sometimes the source of an infection does not manage to be established.
Contact abscesses of an otogenic origin meet more often. The main ways of penetration of an infection at them are preformirovanny bone channels (most often — a bone labyrinth), internal acoustical pass, a vascular way — through veins, in to-rykh there are thrombophlebitises, fibrinferments of the small veins falling into sine, fibrinferments of a sine. An infection, affecting a bone, can directly reach a meninx and cause development of meningitis, an arachnoiditis, extra-or subdural abscess of a back cranial pole.
The main role in developing of otogenic abscesses of M. belongs to staphylococcus and a streptococcus. Bacterial, research of pus from an abscess cavity allowed to reveal the preferential growth of plazmokoaguliruyushchy staphylococcus, hemolitic streptococcus, pneumococcus.
Distinguish acute, subacute and hron, abscesses of M. Development of process continues from 2 to 3 months. Cases of a remittiruyushchy course of abscess, sometimes About one year are seldom observed.
The course of abscess of M. is divided into four periods: initial, latent, expressed and terminal. The initial stage lasts 1 — 2 week, is followed by emergence against the background of hron, otitis of headaches, elevated temperature, a fever, nausea, vomiting.
Stage of latency, without nevrol, symptoms, can last from 2 to 6 weeks. The feeling sick, lack of appetite, a weight loss, non-constant periodic subfebrile or standard temperature, slackness, pallor is noted. The period expressed nevrol, symptoms proceeds on average 2 weeks. Serious condition develops — the patient is sluggish, sleepy, indifferent to surrounding. Temperature is more often subfebrile, sometimes normal, seldom high. Substantial increase of temperature can be considered as a symptom of distribution of process on a meninx (see. Meningitis ), break of abscess in likvorny ways or emergence of the accompanying sinus thrombosis (see. Thrombosis ). In blood the neutrophylic leukocytosis with shift of a formula is noted to the left, red blood does not change, hypochromia anemia with anizo-and a poikilocytosis is only occasionally observed. ROE is almost always accelerated (from 20 to 70 mm/hour). In the terminal period meningitis, encephalitis can develop, breaks of pus in a ventricle or subarachnoid spaces are possible. Acute meningitis or thrombophlebitis of a venous sine with a septicopyemia is the most frequent cause of death.
The headache at M.'s abscess pristupoobrazny, preferential in a nape, sometimes, during the involvement in process is mashed a cerebellum, can irradiate to the area of a forehead, eyeglobes or a frontal bone. Less often the headache has diffusion character with the maximum expressiveness in the field of a mastoid. Meningeal symptoms are expressed poorly and can even be absent at all, the stiff neck in the absence of a Kernig's sign is most often observed. The expressed Meningeal symptoms can be observed in an early stage of abscess, before formation of the capsule, or at the abscess complicated by meningitis or break of pus in a cerebral cavity. Early the cerebellar and other focal symptoms prevailing on the party of the main center come to light.
Dizzinesses (see), to-rye are often observed at M.'s abscesses, irritations of both the central vestibular educations, and a labyrinth can be a consequence. Dizzinesses have system character, most often (at a labyrinthitis) are very intensive, depend on a postural change of the head and a body, quite often are followed by vomiting and strengthening of a nystagmus. The most frequent symptom is the spontaneous horizontal nystagmus, multiple is more rare.
Owing to hypostasis, disturbances of circulation of cerebrospinal liquid and a prelum of a brainstem can develop and other symptoms of a trunk origin: decrease in corneal reflexes, a gag reflex, vasculomotor symptoms, paresis of a look up (is more rare aside), pyramidal symptoms — increase in tendon jerks, clonuses of feet, Babinsky's symptom. At a prelum of a myelencephalon, especially at occlusal attacks, disorders of breath and cardiovascular activity can be observed. From cranial nerves most often long a facial nerve (for peripheral type) and the taking-away nerve, is less often observed defeat of a third cranial nerve and caudal group of nerves (IX, X, XI, XII).
Pressure cerebrospinal liquid (see) it is, as a rule, raised, unsharp changes it in the form of nek-ry increase in protein and a cytosis, generally lymphocytic are noted; the cytosis can fluctuate depending on a stage of a disease and weight of a current. So, in an initial stage of abscess and at purulent meningitis the cytosis can be considerable and reach several thousand. However further, during the formation of the capsule of abscess, there is a bystry sanitation of cerebrospinal liquid though quite often the condition of the patient continues to worsen. This dissociation between improvement of indicators of cerebrospinal liquid and an aggravation of symptoms of the patient is characteristic of abscess. In the presence of sharp increase intracranial pressure (see) and secondary trunk dislocation symptoms the spinal puncture (see) can be made only in the conditions of a neurosurgical hospital.
At M.'s abscesses in 40% of cases congestive disks of optic nerves are noted (see. Congestive nipple ). Bystry increase of intracranial pressure leads to bystry progressing of hypostasis on an eyeground. Frequent hemorrhages in fabric of an optic disk and in a surrounding retina are observed that it is connected with increase in permeability of a vascular wall under the influence of toxins.
Occasionally, in addition to the specified changes, the optic neuritis is observed. At neuritis visual acuity falls quicker, than at developments of stagnation. In all cases in the postoperative period there occurs regress of hypostasis of a disk of optic nerves during 1 — 6 week. Lack of regress can indicate or formation of new abscess, or existence of inflammatory process.
At M.'s abscesses bradycardia is noted, edges it can be connected as with increase in intracranial pressure, and irritation of a vagus nerve and its involvement in inflammatory process.
Sometimes it is difficult to distinguish M.'s abscess from extradural abscess in a back cranial pole. At extradural abscess temperature is more often normal or subfebrile. Sharp temperature increase always demonstrates development of meningitis and thrombosis of a sine. The composition of blood and cerebrospinal liquid can be not changed. In a wedge, a picture the constant headache preferential in occipital area prevails, edges extends also to a neck, Meningeal symptoms are sometimes observed. Focal symptoms are poorly expressed to a thicket, the easy lacks of coordination and hypotonia in gomolateralny extremities, paresis of the VI cranial nerve which were more expressed on the party of defeat, a spontaneous nystagmus take place. The important differential symptom testimonial of existence of extradural abscess, suppuration from an ear or fluctuation of pus in the depth of acoustical pass, synchronous to pulse is. Perhaps simultaneous existence of extradural abscess and abscess of a cerebellum. M.'s abscesses after hron, otitis arise by 7 — 9 times more often than after acute.
For diagnosis of abscesses, in addition to a X-ray analysis of a skull (see. Kraniografiya ) and an electroencephalography (see), are of great importance an angiography of vertebrobazilyarny system (see. Vertebralnaya angiography ) and a computer tomography (see the Tomography computer).
At establishment of the diagnosis of abscess of M. and the accompanying picture of an encephalomeningitis before operation performing intensive antiinflammatory care is necessary (antibiotics, streptocides, anti-staphylococcal anatoxin, etc.). If on this background the condition of the patient does not improve, then resort to an operative measure (see below).
The forecast for life at timely recognition and treatment of abscess of M. favorable.
Parasitic diseases. Because parasitic diseases of M. — generally display of multiple cysticercosis or echinococcosis of a brain, cerebellar symptomatology at them is combined with signs of defeat of other departments of a brain. At an arrangement of an echinococcus or a cysticercus in a cavity of the fourth ventricle the wedge, a picture of the alternating occlusion is observed. If the parasite is not fixed to a wall of the fourth ventricle and freely moves, the heavy occlusal attacks with the forced fixed position of the head developing against the background of almost full wellbeing in the mezhpristupny period are observed.
Treatment operational. It comes down to opening of a back cranial pole with a section of a worm and to removal of a bubble from a cavity of a ventricle. In more exceptional cases it is possible to move apart median structure of the fourth ventricle (Marangdi's opening) without section of a worm. After removal of a bubble outflow of cerebrospinal liquid from a cavity of the fourth ventricle is recovered.
From neuroectodermal tumors often meet astrocytomas and medulloblastomas, from meningososudisty tumors — angioretikulema and sarcomas. In M. also metastasises of cancer are observed.
In relation to all tumors of M. at children's age, by data A. A. Artaryan (1973), astrocytomas make 60%, medulloblastomas — 24%, sarcomas — 16%, angioretikulema meet less often. Angioretikulema (see) are localized preferential in M. and it is extremely rare in a great brain.
Astrocytoma (see) has the nodal form and it is characterized by expansive growth. The tumor, as a rule, does not infiltrirut widely brain fabric, and sharply condenses, stretches and deforms bark, white matter, M. V kernels nek-ry cases the astrocytoma has big prevalence, growing into a cavity of the fourth ventricle and sometimes into a brainstem. In the latter case it is not always easy to establish whether there was a tumor initially in M. or in a brainstem. The astrocytoma is more often localized in medial departments of a hemisphere and a worm M., in 24,3% of cases it sprouts a roof of the fourth ventricle and grows into his cavity, in other cases only squeezes a roof, blocking a cavity of the fourth ventricle and by that causing an occlusal edema of a brain (fig. 19). In astrocytomas it is often noted kistoobrazovany (fig. 20).
Medulloblastoma (see) in 87,5% of cases sprouts a roof of the fourth ventricle, carries out his cavity and in 55% of cases burgeons in a brainstem. In most cases proceeds from the lower worm. The medulloblastoma has infiltrative growth, sprouts bark, legs, gear kernels (fig. 21). It is the most malignant tumor, widely metastasizes edges within c. the N of page on subarachnoid spaces of back, is more rare than a brain, in some cases on walls of the third and side ventricles. The medulloblastoma extends also on periadventitsialny spaces.
Formation of cysts, the sizes to-rykh often is characteristic of an angioretikulema exceed the sizes of the tumor. Compact angioretikulema, free of cysts or with small cysts, are observed less often.
Sarcoma (see) meets in the form of diffusion education and in the form of a nodal form. In the latter case the tumor is localized or on the centerline, in a grub and the fourth ventricle, or in a hemisphere of a cerebellum. In 52,3% of cases the tumor sprouts a roof of the fourth ventricle and carries out his cavity.
M.'s sarcoma metastasizes within c. N of page on covers of a head and spinal cord, and also in limf, nodes, muscles, a bone tissue and it is extremely rare in internals.
M.'s tumors belong to subtentorial tumors, meet preferential at children's age. By data Ying-that neurosurgery of H. N. Burdenko of the USSR Academy of Medical Sciences and Leningrad in-that neurosurgery of A. L. Polenov, M.'s tumors at adults occur in 11,7% of cases, and at children in 38,4% in relation to all intracranial tumors, in relation to subtentorial tumors — in 37,6% of cases at adults and in 68 — 70% at children.
M.'s tumors, as a rule, affect children aged from 3 up to 12 years, children at the age of 4 years most often are ill, but the tumor can be shown also at chest age. At boys the medulloblastoma is observed twice more often than at girls. Angioretikulema M. are quite often combined with an angiomatosis of a retina and malformations of internals (see. Gippelya — Lipdau a disease ).
The clinical picture of a tumor of M. generally depends on the gistobiologichesky characteristic of a tumor, a phase of development of a disease and age of the patient. Astrocytomas and angioretikulema have a high-quality current, medulloblastomas and sarcomas — malignant.
At medulloblastomas and sarcomas the general symptoms of intoxication are observed, to-rye are sometimes sharply expressed and can be found at the beginning of a disease: a weight loss, loss of appetite, slackness, fatigue, sometimes concern, irritability, astenisation, increase limf, nodes, change in blood (a leukocytosis with shift of a formula to the left), temperature variations.
Display of a disease begins with symptoms of increase in intracranial pressure more often — gipertenzionno-gidrotsefalny attacks of a headache, at height to-rykh there is vomiting (see. Hypertensive syndrome ), less often from local symptoms of defeat
of M. U of children this symptomatology quite often comes to light after a bruise of the head, inf. diseases etc., to-rye provoke a wedge, manifestation of tumoral defeat of M. proceeding so latentno. By the time of a wedge, displays of a disease the roentgenogram of a skull reveals the general gipertenzionny changes, and sometimes and local in the form of a rarefikation of the rear edge of a big occipital opening, thinning of scales of an occipital bone over a tumor, development of emissariums in the field of a sinus drain and along a comb of an occipital bone. In some cases owing to calcification of a tumor on kraniogramma petrifikata come to light.
As a result of increase in intracranial pressure congestive disks of optic nerves with the progressing decrease in visual acuity develop, up to development of a blindness. Children of younger age depending on fiziol, features can have a pallor of disks of optic nerves in the absence of explicit hypostasis or against the background of unsharply expressed congestive disks of optic nerves.
Increase in intracranial pressure sometimes leads to disturbances of mentality (euphoria, lack of criticism, decrease in memory, intelligence) and disbolism.
One of the frequent symptoms accompanying M.'s tumors is forced position of the head with an inclination usually aside, M. opposite to defeat, is more rare in the same. At emergence of an attack of headache occlusal gidrotsefalnogo character position of the head changes: it or is thrown back back [at occlusion in the field of a water supply system of a brain (a silviyev of a water supply system) and oral departments of the fourth ventricle], or given to a breast and lowered down (at occlusion in the field of Marangdi's opening and caudal departments of the fourth ventricle).
At increase in intracranial pressure and development of an occlusal edema of a brain the shift of almonds in a big occipital opening (an occipital and dural funnel) with a prelum of a myelencephalon and the shift of verkhneperedny department of M. in a tentorial opening (a pakhionova a hole) with a prelum of a mesencephalon is possible. At the shift of almonds in a big occipital opening there is their vklineniye between bone edge of an occipital opening and an arch of the first vertebra, on the one hand, and a myelencephalon — to another. Clinically the syndrome of the lower vklineniye of almonds of M. is shown by sharp strengthening of headaches, especially in occipital area, the forced and fixed position of the head, vomiting, dizziness, cardiovascular disturbances, meningeal symptoms, in the beginning increase, and then an urezheniye of breath up to its stop. Acute development of a syndrome with a sudden apnoea is sometimes observed (see. Dislocation of a brain ).
Local symptoms of defeat of M. in the form of disturbance of a statics, gait and coordination of movements in extremities are observed in various degree in 95 — 96,9% of cases of tumors of M.
At defeat of a hemisphere of a cerebellum or the gear kernel located in its depth arise the expressed hypotonia of muscles and lacks of coordination in extremities on the party of defeat. At defeat of a worm M. disturbances of a statics and gait are noted. Sometimes the ataxy in the lower extremities is expressed more, than in upper. According to Brokhard's concept (Brockhard, 1960) about somatotopichesky localization in M. this results from the fact that the lower extremities are presented in front departments of both an upper, and lower half of M., namely these front departments at M.'s removals in the cerebellar and brain (big) tank of a brain or a tentorial opening suffer more than others.
Children of younger age have disturbances of a statics and gait prevail over lacks of coordination of movements in extremities even at localization of a tumor in a hemisphere of M.
Trunk symptoms almost always accompany tumors M. Naiboley often at the same time the bridge (in 97,3% of cases), then the mesencephalon (71,6%) and a myelencephalon (28,6%) suffers varoliyev. From trunk symptoms are observed spontaneous horizontal, the multiple nystagmus, decrease in corneal reflexes, loss of a railroad nystagmus, paresis of a look up, disturbance of convergence, decrease in a gag reflex, decrease in reaction of a pupil to light, etc. is more rare. Children of younger age in 36% of cases can are absent or have a non-constant spontaneous nystagmus and slight.
At localization of a tumor in upper parts of M. and a prelum of a mesencephalon, in addition to the symptoms mentioned above, there can occur increase in a tone of muscles of extrapyramidal character, an intentsionny and static tremor, myoclonias in extremities are possible.
At M.'s tumors disorder of function of cranial nerves is noted. From them the VI nerve, more often on both sides most often suffers, is more rare — with one, V a nerve — from one or both parties, the VIII nerve — IX and X nerves — from one or both parties are preferential on the one hand.
At tumors of M. which are followed by substantial increase of intracranial pressure usually abstain from a spinal puncture since it can lead to M.'s removal in a big occipital opening and to infringement of a brainstem. If the spinal puncture is necessary for specification of the diagnosis, then it (in case of increase in intracranial pressure) is made along with a ventriculopuncture (see).
Cerebrospinal liquid at M.'s astrocytomas in 43% of cases remains normal, in 5% — has gidrotsefalny character and in 52% — in it belkovokletochny dissociation is observed. Increase in protein from 0,4 to 1 per milles takes place as during the growing of a tumor into the fourth ventricle, and at its localization only in M. Chashche increase in protein is observed at cystous tumors.
At medulloblastomas, in addition to proteinaceous and cellular dissociation, edge it is observed in 61% of cases, sometimes there is a cytosis. At the same time lymphocytes, the changed neutrocytes, macrophages prevail. In 3% of cases in cerebrospinal liquid tumor cells are found. The structure ventrikulyarno - cerebrospinal liquid at M.'s astrocytomas has preferential gidrotsefalny character, at medulloblastomas, despite an edema, it often contains the increased amount of protein (0,3 — 1,5 per milles).
In 1948 I. M. Irger, L. A. Koreysha, E. S. Tolmasskaya suggested to register electric activity of M. by means of the needle electrodes stuck in a periosteum of scales of an occipital bone. It turned out that potentials with a frequency of 30 — 40 fluctuations in 1 sec. at tumors of a worm are more changed, than at tumors of a hemisphere of M. At localization of a tumor in M.'s hemisphere of change of electric activity on the party of the center consist preferential in emergence of slow waves with a frequency of 6 — 8 fluctuations in 1 sec. Besides, electric activity of M. or sharply decreases, or changes. At children at M.'s tumors, in addition to all-brain changes on EEG, in zatylochnotemenny, occipitotemporal departments of hemispheres, and also in frontal lobes of a brain, different forms of disturbance of biopotentials are registered, to-rye arise on gomo-or contralateral to the center to the party. The high-amplitude slow waves arising on EEG most often are shown in contralateral frontal area.
Ekhoentsefalografiya (cm), at M.'s tumors reveals as indirect symptoms of a tumor, defining an edema side and the third ventricles, and straight lines — by receiving abnormal signals from the tumor. Abnormal signals to a thicket are registered at cystous tumors.
X-ray contrast methods of a research are of great importance, in particular ventrikulografiya (see) by means of a mayodil or an emulsion mayodit. Ventrikulografiya with mayodily allows to gain clear idea of the level of occlusion in caudal departments of likvorny system (silviyev a water supply system, the fourth ventricle, Marangdi's opening), specifies localization of a tumor in various departments of M., its relation to the fourth ventricle, taking into account kraniotserebralny topography (see) allows to judge degree of shift of educations of M. in a tentorial opening.
The vertebralny angiography is informative, edges at M.'s tumors are shown by shift basilar and the main branches of cerebellar arteries and in nek-ry cases reveals own network of a tumor.
The great value in diagnosis of tumors of a brain, and in particular M.'s tumors, is gained by tracer techniques of a research and a computer X-ray tomography. The last gives not only clear idea of localization of a tumor, but also allows to judge a condition of all ventricular system.
Conservative therapy at M.'s tumors, as well as at other tumors of a brain, has symptomatic character. At a gipertenzionny syndrome apply dehydrating agents (lasixum, furosemide, etc.).
The principles of operational treatment are stated below.
Cysts in M. can be: 1) disgenetichesky (most often are found in children); 2) as result of the organization of hemorrhages, heart attacks, abscesses, damages; 3) the tumoral nature (at angioretikulema, M.'s astrocytomas). Disgenetichesky cysts are combined with agenesias of a worm and hemispheres. Siringomiyelichesky cavities in M. are formed seldom.
The majority of cystous cavities of M. is observed at his tumors; they or are located in a tumor, or adjoin directly to it. Clinically it is very difficult to distinguish cysts of a tumoral and not tumoral origin. The cystous arachnoiditis in a back cranial pole simulating M.'s tumor meets rather seldom.
Treatment of cysts operational — make opening of a cystous cavity.
the General principles of surgical interventions, preoperative preparation and anesthesia — see the Brain, philosophy of surgical interventions.
Operations at abscesses of a cerebellum
there are three forms of an operative measure at M.'s abscesses: total removal of the encapsulated abscess, a puncture method, drainage of abscess.
The most effective method is total removal of abscess with the capsule: make broad trepanation of a back cranial pole, cut fabric M. (cross, it is longitudinal or a circular method), edges of a brain wound are laid over by wadded strips and moved apart by pallets, allocate the encapsulated M.'s abscess from surrounding brain fabric and delete is total, together with the capsule. It is necessary to show at the same time extra care not to break through the capsule. If the capsule is sharply strained, then it is better previously by means of a puncture partially to empty abscess, having protected tissue of a brain wadded strips so that pus did not get to likvorny spaces and then to remove together with the capsule. In cases when the capsule did not manage to be formed, the resection of a hemisphere of M. together with an abscess cavity is shown. After removal of abscess put stitches on soft tissues of N a deaf seam on skin.
Many otorhinolaryngologists consider it expedient to make a puncture or drainage of abscess directly through the infected cavity of an ear or ahead from a sigmoid sine (a trautmannovsky triangle), or a kzada from it. The section of a firm cover of a brain shall not exceed 2 mm. The puncture is made a stupid cannula. Treatment consists or in repeated suctions of pus with washing of a cavity Furacilin and administration of solution of an antibiotic in it, or in opening of abscess and its drainage. Operational treatment of abscess is carried out against the background of the intensive antibioticotherapia which is carried out taking into account sensitivity of microflora of abscess of M. in combination with sulfanamide drugs. Also dehydrational, desensibilizing, fortifying therapy using vitamins is necessary.
M.'s Tumour demand earlier operative measure. This situation belongs not only to malignant tumors, but also to high-quality, to-rye at their long existence reach the big sizes and cause irreversible changes in the structures of a brain surrounding a tumor.
Operation shall be made against the background of cerebral decompression and is not shown at height of gipertenzionno-gidrotsefalny crisis. The last demands the acute neurosurgical management in the form of a puncture of cerebral cavities and establishment (it is desirable in the right front horn) of a long drainage of ventricular system (see. Ventriculopuncture ). In 2 — 3 days after cerebral decompression, reduction of wet brain, improvement of the general state an operative measure is shown. Nek-ry authors consider expedient imposing of a long ventricular drainage in 2 — 3 days prior to operation even in the absence of occlusal crises.
Position of the patient on the operating table depends on its age, a state, expressiveness of a gidrotsefalny component. It can be horizontal — in edgewise position or in a sitting position. Children of early and younger age with the expressed edema of a brain usually operate in situation on right, is more rare on the left side.
Operation is always made under the general intubation anesthesia with addition of local anesthesia in the field of the line of a section and amotio of muscles from scales of an occipital bone.
Prior to operation the puncture of the left or right back horn of a side ventricle is made for removal of cerebrospinal liquid and reduction of chamber pressure that in turn leads to reduction of venous bleeding from congestive veins of soft tissues and emissarny veins of scales of an occipital bone. If necessary the puncture of a ventricle is made repeatedly during operation.
Opening of a back cranial pole. Access to a back cranial pole is reached by midsection of soft tissues in cervicooccipital area, from an outside occipital ledge to an acantha of the III cervical vertebra. The line of a section goes strictly on the centerline, along a nuchal sheaf. Cut this sheaf and muscular layers, the last separate the raspatory from scales of an occipital bone and an arch of the I cervical vertebra. During the separating of muscles from scales of an occipital bone special attention is paid on preservation of an integrity of muscles and an aponeurosis in the field of their attachment to an outside occipital ledge since it facilitates the subsequent tight closing of a wound. After separating of muscles resect a back arch of the I cervical vertebra and scales of an occipital bone up — before emergence of edge of a cross sine, from top to bottom — skusyvat the rear edge of a big occipital opening throughout 3 cm. The back arch of the Atlas is resected at adults throughout 3 cm. Removal it on a bigger extent can cause wound of a vertebral artery. At children depending on age the sizes of a resection of an arch and scales of an occipital bone change. By data A. D. Shiyanova (1969), aged from 1 up to 3 years cross sectional dimension of a trepanation opening in scales of an occipital bone shall be no more than 75 mm because of danger of damage of mastoidal graduates, to-rye at this age have a diameter of 1 mm. The distance between vertebral arteries over the Atlas is equal to 20±3 mm. Children from 3 to 7 years on the peppery size of a trepanation opening can have 85 — 90 mm. The distance between vertebral arteries over the Atlas is equal to 25±3 mm. At children from 7 to 12 years cross sectional dimension of a trepanation opening can reach 95 — 100 mm, distance between vertebral arteries of 29±2 mm.
If to take as a basis diameter of a spinal cord with its covers and to make a resection of a back arch of the Atlas only in these limits, danger of wound of a vertebral artery is minimized.
Opening of a firm cover of a brain is usually made a Y-shaped section with bandaging of an occipital sine and cliping or coagulation of regional. Use also crucial and scrappy incisions. The scrappy section is made with the basis turned to a cross sine. At localization patol, process in one hemisphere of M. use crucial incision or a section in the form of a sickle; in the latter case the section of a cover is conducted over M.'s hemisphere, parallel to a cross sine, further — parallel to defect of a bone, otstupya from edge on 6 mm, and connect it to the line of a section of the big tank, to-ruyu in a case patol, the process limited to one hemisphere opened not on the centerline, and otstupya on 3 — 4 mm to the opposite side from the center of defeat. At such section cross only one final branch of an occipital sine, and another remains safe. Both on central, and on a peripheral piece of the crossed branch of an occipital sine impose big clip-on earrings (see. Cliping of vessels ). This section allows to receive sufficient tightness during the mending of a cover.
Outer inspection of a cerebellum is made for the purpose of orientation in topography of a brain and a tumor. At survey establish existence of symmetry or asymmetry in an arrangement of hemispheres, expansions and smoothness of crinkles, changes of outward, coloring, an arrangement of vessels. Much attention should be paid to shifts of the centerline of M., omission of almonds, at Krom the almond on the party of the center is lowered below opposite, sometimes increased in volume, passes for the centerline and fills with itself the cerebellar and brain tank, and also to changes of a worm, to-ry at an arrangement of a tumor in it extends and eminates. Then on the small site remove an arachnoid membrane from bottom edge of almonds, the narrow pallet move apart almonds and examine Marangdi's opening, lower parts of the fourth ventricle, find out whether there is an outflow of liquid from the fourth ventricle through Marangdi's opening. It is hard to find deeply located intracerebral tumor sometimes. In this case are guided on indirect signs, a wedge, to symptoms and data of a X-ray contrast research; make M.'s puncture in a zone of an estimated tumor. In the presence of a tumor consolidation is felt or cystous liquid appears. The puncture is made a stupid cannula after pointed coagulation of bark.
Oncotomy. Apply to approach to a tumor of a hemisphere of M. as longitudinal (vertical) sections of M. — across crinkles, and cross — along crinkles. At an arrangement of a tumor in a grub the section is made in lengthwise direction. After coagulation of vessels of a cover of a worm it is cut strictly on the centerline by means of electrothermic coagulation (see. Diathermocoagulation ). Pallets move apart edges of a dissect worm and move ahead in depth towards the fourth ventricle to an exposure of a tumor. After an exposure of a tumor impose wadded strips on edges of a brain wound and move apart them pallets, close a wadded strip area of the cerebellar and brain tank to prevent flowing of blood or cystous liquid in likvorny spaces, and start allocation of a tumor and removal it.
By means of a suction empty a cyst and easily delete mucous sites of a tumor; more dense sites take a fenestrated forceps and after coagulation of the vessels suitable to them, delete. Sometimes the oncotomy is made by means of a surgical spoon. Bleeding at an oncotomy is stopped tampons with hydrogen peroxide and coagulation (see. Bleeding ). At germination of a tumor in the fourth ventricle aim to allocate first of all the upper pole of a tumor tamponing upper parts of a ventricle and silviyev a water supply system. After allocation of an upper pole of a tumor and the expiration of cerebrospinal liquid M.'s protrusion decreases, and then delete lower parts of a tumor.
The method of a circular resection of M. entered practice, with the help to-rogo broad access to a tumor, its allocation with border with brain fabric and removal by a uniform node is provided that the bleeding which is quite often arising at an oncotomy kuskovaniy warns. The circular resection is made taking into account a topographical arrangement of gear kernels. The projection of kernels to a lower surface of M. is the share of medial and average departments of almonds; on an upper surface of M. — on medial departments of a lobby and back quadrangular segment. In the presence patol. the center, in particular at M.'s tumors, topografoanatomichesky ratios change. At tumors of a worm gear kernels are sharply displaced from the centerline aside and stretch on the periphery of a tumor from two parties, as if bordering it (fig. 22).
Sometimes teeth of a kernel directly prilezhat to tumoral fabric, are sometimes separated from it by a layer of white matter. Malignant tumors sprout gear kernels. At tumors of a hemisphere of M. there is a shift of a gear kernel, a cut is pushed aside medially to the centerline and borders medial edge of a tumor (fig. 23).
The circular resection is made in the field of the lower semi-lunar segment and upper parts of a biventral segment (fig. 24) in their medial, average or lateral third depending on localization of a tumor. If the tumor is occupied by a worm and extends to medial departments of one of M.'s hemispheres, make at the same time a resection of a worm in the field of a hillock and upper parts of a pyramid and medial departments of a hemisphere of M., in the field of semi-lunar and biventral segments (fig. 25).
Before a resection make coagulation of vessels around on the surface of a brain on the site diameter apprx. 3 cm, then scissors cut koagulirovanny vessels and by means of a suction delete bark and the subject white matter within this site. Usually white matter over a tumor is resected on circles of a little bigger diameter, than diameter of the excised bark, to a wide exposure of a surface of a tumor. Edges of a brain wound lay over wadded strips. The tumor is taken a fenestrated forceps and by means of a suction and coagulation under control of sight begin to allocate it on a circle, on border with brain fabric. At allocation of the tumor growing from a worm it is necessary to consider that the displaced gear kernels are located on the periphery of a tumor, on its outer edge. In these sites exfoliate a tumor from the subject brain fabric by means of a tupfer better. At an oncotomy, M. occupying a hemisphere, the same care is necessary at allocation of its medial edge.
During an operative measure on a back cranial pole the surgeon should manipulate generally around a trunk and branches of the lower back cerebellar artery. At an oncotomy of M. much attention is paid to the prevention and a stop of bleeding since even small accumulation of blood in the field of a back cranial pole leads to a prelum and hypostasis of a brainstem. Meanwhile the lower back cerebellar artery, its main branches often are the main source of blood supply of a tumor, ii sometimes is not possible to avoid damage of a trunk of an artery. Switching off of a trunk of the lower back cerebellar artery is made in extreme cases, in need of a stop of bleeding, radical removal of the related tumor, disturbance of food of the remained sites of tumoral fabric.
Switching off of the lower back cerebellar artery needs to be made at medial edge of an almond, in lower parts of a paramedian furrow just before its division into branches, krovosnabzhayushchy M.
After an oncotomy and a careful hemostasis make layer-by-layer mending of soft tissues with imposing of two rows of seams on muscles, then on an aponeurosis, hypodermic cellulose and a deaf seam on skin. The firm cover of a brain remains not sewn up. Only in cases of full removal of a benign tumor without any complications with recovery of a likvoroottok, in the absence of hemorrhages, at M.'s retraction and its good pulsation the firm cover can be sewn up.
Often the medulloblastoma, is more rare sarcoma, filling a cavity of the fourth ventricle, is soldered to its bottom and therefore it cannot be completely removed. In these cases whenever possible maximum oncotomy with recovery of outflow of cerebrospinal liquid from a ventricle is made. Repeated operations at medulloblastomas as well as at sarcomas, the effect is not given in connection with considerable prevalence of tumoral process and tendency of a tumor to innidiation. Postoperative mortality at medulloblastomas reaches 22,3%.
M.'s astrocytomas in most cases are subject to single-step full removal. At an astrocytoma a repeated operative measure owing to the continued growth, and sometimes and a recurrent tumor quite often is required. Repeated operations if the astrocytoma does not sprout a brainstem, are effective and lead to practical recovery of the patient. At malignant tumors of M. carry out also radiation therapy. Indications and its technique — see. Brain, tumors .
Anatomy, histology, embryology and physiology — Aleksanyan A. M. About functions of a cerebellum, M., 1948, bibliogr.; Arshavsky Yu. I. A role of a cerebellum in management of the movements, in book: Fiziol, movements, under the editorship of V. S. Gur-finkel, etc., page 163, L., 1976; Bekhterev V. M. Bases of the doctrine about functions of a brain, the Cerebellum, century 4, SPb., 1905; Grigoryan R. A. and Fanardzhyan V. V. Mozzhechok, in book: The general and private fiziol, a nervous system, under the editorship of P. G. Kostiuk, etc., page 288, L., 1969; Dzugayevas. B. Conduction paths of a brain of the person (in ontogenesis), M., 1975; And r-of e r I. M., To about r e y sh and L. A. and Top masses to and I am E. S. Electric activity of a cerebellum of the person is normal also of pathology, M., 1959; Karamyana. I. Evolution of functions of a cerebellum and big cerebral hemispheres, L., 1956; To about z-l ovsky I. B. Afferent control of autokinesias, page 126, M., 1976; Blood supply of the central and peripheral nervous system of the person, under the editorship of B. V. Ognev, M., 1950; Senta-otaiya.iar bi 6M. Conceptual models of a nervous system, the lane with English, M., 1976; Fanardzhyan V. V. Regulatory mechanisms of the ascending influence of a cerebellum, Yerevan, 1966, bibliogr.; it, About the neural organization of efferent systems of a cerebellum, L., 1975, bibliogr.; Fir-s about in L. A. Change of electric activity of a cerebellum at exteroceptive (sound and light) irritation, Fiziol. zhurn., t. 53, No. 10, page 934, 1957; Aspects of cerebellar anatomie, ed. by J. Jansen a. A. Brodal, Oslo, 1954; B o 1 k L. Haup-tziige der vergleichenden Anatomie des Cerebellum der Saugethiere, Mschr. Psychiat. Neurol., Bd 12, S. 432, 1902: With 1 a-r a M. Das Nervensystem des Mensclien, Lpz., 1959; Dow R. S. a. M o r u z z i G. The physiology and pathology of the cerebellum, Minneapolis, 1958, bibliogr.; E with with 1 e s J. Page, Ito M. and. S z e n t and g o-t h an i J. The cerebellum as a neuronal machine, B. a. o., 1967, bibliogr.
Pathology — To Arsa of N and To., Opres-k at II. and And about N of e with to at Page. Not traumatic intra parenchymatous hematomas of a great brain and cerebellum, Zhurn, neuropath. and psikhiat., t. 58, No. 1, page 13, 1958; And r t and r I am A. A N. Tumors of a cerebellum at children, M., 1979; B of l and and to about in S. M. and Smirnov N. A. Shifts and deformations of a brain, M., 1967; Biro * I. D tooth. Tumors of a cerebellum, Kiev, 1970; And r of e r I. M. Klinika and surgical treatment of tumors of a cerebellum, M., 1959, bibliogr.; Koltover A. N. and d river. Pathological anatomy of disturbances of cerebral circulation, M., 1975; Konovalov N. V. A pathophysiology and pathology of a cerebellum, M. — L., 1939, bibliogr.; M. B. and Fedorov E. A. crawl. Main neuropathological syndromes, M., 1966; Lev and N and G. Ya. Infarkt of a cerebellum at hypertensive crisis, Arkh. patol., t. 40, L'g 10, page 68, 1978; L and x t of e r m and N of L. B. and X and trin L. X. Traumatic intracranial hematomas, M., 1973; M and to yu with and to V. A. Ancestral features of the person, the lane with English, M., 1976; The Multivolume guide to neurology, under the editorship of S. N. Davidenkov, t. 5, page. And, M., 1961, t. 7, page 217, M., 1960; The Multivolume guide to pathological anatomy, under the editorship of A. I. Strukov, t. 2, page 700, M., 1962; Vascular diseases of a nervous system, under the editorship of E. V. Schmidt, M., 1975; T r and at m f about in A. V. Topical diagnosis of diseases of a nervous system, L., 1974; X about m and N with to and y B. S. Histologic diagnosis of tumors of the central nervous system, M., 1969; Schmidt. V. Angioretikuloma of a brain, page 64, M., 1955; The cerebellum in health and diseases, ed. by W. S. Fields a. W. Willis, p. 477, St Louis, 1970; F i-s with h e r W. Symptomatologie und Diagno-stik der Tumoren des Kieinhirnraumes, Beitr. Neurochir., Hft 10, 1965; Handbook of clinical neurology, ed. by P. J. Vinken a. G. W. Bruyn, v. 1 — 36, Amsterdam a. o., 1975 — 1979; Handbuch der speziellen patho-logischen Anatomie und Histologie, hrsg. v. O. Lubarsch u. a., Bd 13. T. 4, B. u. a., 1956; K o r n y e at St. Histopathologie und klinische Symptomatologie der ano-xisch-vasalen Hirnschadigungen, Budapest, 1955; K o os W. T. a. M i 1 1 e r M. H. Intracranial tumors in infants and children, St Louis, 1971; Kuhlendahl H., Stochdorph O. u. Hiibner G. Zur nosologischen Stellung und histologi-schen Herleitung des sogenannten Kleinhirn-astrozytoms, Acta Neurochir. (Wien), Bd 32, S. 235, 1975; Lazorthes G. L’ hemorragie cerebrale, P., 1956; Loeb C. Meyer J. S. Strokes due to vertebrobasilar disease, Springfield, 1965; S y p e r t G. W. a. A 1 v o r d E. C. Cerebellar infarction, Arch. Neurol. (Chic.), v. 32, p. 357, 1975; V i r u e g an A. J. e. a. Astrocitomas de cerebello, Rev. esp. Oto-neuro-oftal., v. 34, p. 1, 1976; Z ii 1 with h K.J. Die Hirngeschwiilste in biologischer und morphologischer Darstellung, Lpz., 1958.
E. I. Gusev; A. A. Artaryan (neyrokhir), S. M. Lozhnikova, V. A. Morgunov (stalemate. An.), V. S. Speransky (An), V. V. Fanardzhyan (physical.).