Lecture
The main neuropsychological syndromes, their structure, the release of the syndrome-forming radical associated with the elimination of certain structural and functional units of the brain from normal operation and the loss of one (or several) factors from the functional system are well developed and described in relation to lesions of the left hemisphere of the brain (A.P. Luria, 1969; 1973). At the same time, further development is required in syndromes of damage to the structures of the right hemisphere of the brain, subcortical nuclei, limbico-reticular complex and commissural formations, which provide for joint integrative activity of the right and left hemispheres of the brain. To date, clinically verified data have been obtained on neuropsychological symptoms associated with the lesion of precisely these brain areas, which allow neuropsychological diagnostics aimed at differentiating the side of the brain lesion, lateral or medial location of the pathological focus, and also on the level of its localization in the systemic structural vertical structure of the central nervous system. The interpretation of these symptoms in theoretical terms and in the context of understanding brain mechanisms and factors has not yet received a complete and systematic understanding. It requires the development of ideas about the features of the structural and functional organization of these brain zones and a new approach to the analysis of those factors in the structure of mental reflection that they provide.
In its practical aspect, neuropsychology is in a developmental situation, the main directions of which are determined, firstly, by the expansion of the possibilities of neurosurgery and neurology, and secondly, by the outlined expansion of the scope of application of the syndromic neuropsychological activity methods to the examination of such groups of patients, where mental disorders have less pronounced than with tumors, the nature and manifest more diffuse. The neuropsychological qualification of the structure of mental disorders at the same time requires a more systematic description of the currently available data on syndromic diagnosis, including what is new in it, which has already become practical, but has not received coverage in previously published fundamental works.
The occipital region of the cerebral hemispheres provides, as you know, the processes of visual perception. In this case, the actual perceptual activity (visual gnosis) is provided by the work of the secondary sections of the visual analyzer in their relationship with the parietal structures. With the defeat of the occipital-parietal regions of the brain (both the left and right hemispheres) there are various disorders of the visual-perceptual activity, primarily in the form of visual agnosia.
Recently, data have been obtained on the role and medial regions of the occipital regions of the brain in the processes of visual perception, since the latter can be disturbed when the pathological process is localized on the medial surface of the occipital regions of the brain.
It should be noted that the diversity of the described options for the violation of visual-perceptual activity is determined by the partial nature of its defect in relation to various types of visual material (real objects, their images, colors, alphanumeric characters, faces of familiar people, etc.) and various levels of realization of visual perception as a complex purposeful activity, based on the actualization of the experience that has formed in the ontogenesis of the past (the actualization of visual representations, the integral complex simultaneous e perception of visual stimuli, the ability to identify visually perceived requirements objects intramodalnyh establishing links between the various characteristics of the information coming to the optic analyzer, and intermodal connections necessary for categorization of visual stimuli on the thinking and speech levels). The variety of manifestations of visual-perceptual disorders, no doubt, are various brain factors providing this leading in the structure of human mental activity modalities of reflection, the analysis and psychological qualification of which is carried out at the level of describing the clinical and psychological phenomena. The reason for this empirical approach is the lack of a unified theory that generalizes the structural and dynamic characteristics of visual perception and takes into account the complex multi-level structure of this function, including its cerebral structural and functional organization.
Violation of the sensory components of the visual function does not, as a rule, lead to disorders of the actual visual perception, defects in the objective reflection of the external environment. Even with significant impairment of visual acuity, even with a sharp narrowing of the visual fields (up to the formation of a "tubular" field of view), visual perception does not lose its substantive relevance, although its speed characteristics may deteriorate, since additional time is needed to adjust the visual system to perform the perceptual task . In these cases, we can talk about the high compensatory capabilities of the visual system, providing orientation in the objective world with a pronounced lack of sensory support.
The only exception is one-sided visual-spatial agnosia (ASD) arising from the defeat of the deep or convexital parts of the right hemisphere of the brain, which has such reference equivalents as a fixed left-sided homonymous hemianopsia or left-sided visual ignoring syndrome.
In the most pronounced forms of development of this pathology, a systemic defect is found in the form of the “non-perception” of those components of visual stimulation that fall into the left visual field. This can be seen when the patient is working with subject images, when drawing objects, and even in an independent drawing of the patient, i.e. when updating visual representations. The visible world and its image seem to fall into two halves: the reflected (right visual field) and the non-reflective (left), which significantly distorts the process of visual perception. Ignoring the left half of the visual field can be detected not only by perceiving and copying subject images, but also in such activities as a self-drawing, estimating time on a clock, and even reading a text, in which only the “visible” right field of view is perceived. The distortion of the content of the text, nonsense, arising in this case does not affect the visual activity of the patient, which is carried out formally, without attempting correction.
To what has been said about ASD, three points should be added that are important in the diagnostic aspect.
First, ASD can also occur in the absence of hemianopia data. In these cases, its manifestations are observed both in expanded form and in the form of a "tendency" to visual disregard, the consequences of which are such changes in visual gnosis, as the text shifts when writing to the right side relative to the edge of a sheet of paper; enumeration of the items depicted in the album not from left to right, but in the opposite direction; skipping individual words of the left edge of the text (with correction if they are meaningful), etc. It is characteristic that similar symptoms can be observed with the defeat of a zone wider than just the posterior parts of the right hemisphere, including the localization of the pathological process in the frontal region.
Secondly, in some cases, the ASO may also occur when the left brain is affected in combination with other symptoms indicating the subdominant features of the left hemisphere in this patient.
Thirdly, the ASO often acts as a polymodal syndrome, manifesting itself in perceptual disregarding not only the left visual field, but also the motor, and tactile, and auditory sphere, i.e. affecting the perception of all the stimuli entering the analyzer systems of the right hemisphere of the brain, and relating to the left, with respect to the scheme of the subject's own body, half of the space.
The very name of this phenomenon - "unilateral spatial agnosia" - emphasizes its systemic nature, the inclusion of the phenomenon in the pathology of various modalities and, very importantly, its complex structure, which is based on the spatial radical. In this sense, the ASO in a series of visual agnosia occupies a special place as a particular manifestation of a more complex (and possibly in terms of the integration of spatial functions) syndrome. Why do clinicians and psychologists often speak of ASO in connection with the visual system? This is largely due to the availability of clinical and experimental vision of this phenomenon in visual-perceptual samples. However, it is easy to detect in the tactile sphere (ignoring the stimulus — touching the left hand while simultaneously touching the right), motor (ignoring the left hand in two-handed tests) and auditory (ignoring the stimuli shown on the left ear, in the dichotic listening technique). APA is also detected in the patient's behavior; the patient does not use his left hand, "forgets" to put on slippers on his left foot, stumbles upon objects on the left when moving in space, etc.
The mechanisms of formation of this phenomenon are not yet clear. Attempts to attribute it to attention disorders are, in our opinion, unproductive. A more interesting, although rather schematic, explanation of this clinical phenomenon in terms of “psychological protection” and a distorted inner picture of the disease may be. Especially since almost always OOA is combined with anosognosia.
In addition, recently the concept of the relation of the right hemisphere to the individual-semantic formations in the personality structure has been developing. The latter circumstance may be the cause of distortion in the lesion of the right hemisphere of the internal picture of the disease in its sensory and personal-evaluative components.
Independent diagnostic value in neuropsychological practice is represented by other types of visual agnosia: subject, simultaneous, facial, symbolic, and color.
Subject agnosia occurs when a “wide zone” of the visual analyzer is damaged and can be characterized either as the absence of a recognition process or as a violation of the integrity of the perception of an object with the possible recognition of its individual signs or parts. The impossibility of visual identification of an object outwardly can manifest itself as an enumeration of individual fragments of an object or its image (fragmentation), and the isolation of only individual signs of an object that are insufficient for its complete identification. Examples of objective agnosia that correspond to these two levels are: identification of the image of "glasses" as a "bicycle", since there are two circles united by crossbars; identification of the "key" as a "knife" or "spoon", based on the selected signs of "metal" and "long."
In both cases, as indicated by A.R. Luria, the structure of the act of visual perception is incomplete, it does not rely on the entire set of features necessary and sufficient for the visual identification of an object.
For our part, we would like to point out not only the incompleteness (fragmentation) of visual perception, but also the distortion of the very act of visual perception as compared with the norm, where the object is recognized simultaneously, at one time. The expanded, “reasoning” form of visual perception, which it acquires in the syndrome described here, in healthy people can only be seen in the complicated conditions for identifying unfamiliar objects, i.e. objects whose image is missing in the individual memory of a person. It cannot be ruled out that one of the mechanisms of subject agnosia can be a violation of the mnemonic level of operation of the visual analyzer, which prevents the comparison of the available stimulus with its equivalent in memory.
Subject agnosia can have varying degrees of severity — from maximal (agnosia of real objects) to minimal (difficulty in identifying contour images in noisy conditions or when superimposed on each other). As a rule, the presence of a developed subject agnosia indicates a bilateral lesion of the occipital systems.
With unilateral lesions of the occipital regions of the brain, differences in the structure of visual, subject agnosia can be seen. The lesion of the left hemisphere is more pronounced as a violation of the perception of objects according to the type of listing of individual parts, while the pathological process in the right hemisphere leads to the actual absence of an act of identification. Interestingly, at the same time, the patient can evaluate a visually presented object by its significant characteristics, answering questions from the investigator about the relationship of the subject to "living - inanimate", "dangerous - harmless", "warm - cold", "big - small", " naked - fluffy ", etc.
Differential diagnostic signs of right-sided subject agnosias are slowing down the process of identifying objects, as well as more accurate assessment of the patient’s schematic images compared to realistic ones, and narrowing the volume of visual perception, which is concurrent and more rough manifestation as an independent violation of visual perception.
Before proceeding to the description of this form of visual disorders, we note that in the case of a unilateral defeat of the “wide visual zone”, one can see a modal-specific violation of the arbitrary memorization of a sequence of graphic stimuli, which manifests itself in a narrowing of the volume of reproduction with the lesion of the left hemisphere and most clearly appears when introducing interfering task. A modal-specific mnestic defect in the visual sphere with a lesion of the right hemisphere is found in the difficulties of reproducing the order of the elements included in the memorized sequence of graphic material.
Simultaneous agnosia occurs with bilateral or right-sided lesions of the occipital-parietal regions of the brain. The essence of this phenomenon in its extreme expression is the impossibility of simultaneous perception of several visual objects or a situation in a complex. Only one subject is perceived, more precisely, only one operational unit of visual information is processed, which is currently the object of the patient’s attention. For example, in the task “to put a dot in the center of a circle” there is an inconsistency of the patient, since it requires simultaneous perception in the interrelation of three objects: the contour of the circle, the center of its area and the tip of the pencil. The patient sees only one of them. Simultaneous agnosia does not always have such distinct severity. In some cases, there are only difficulties in the simultaneous perception of a complex of elements with the loss of any details or fragments. These difficulties can manifest themselves in reading, in drawing or in self-drawing. Often simultaneous agnosia is accompanied by a violation of eye movements (ataxia of the eye).
One-sided lesion of the left occipital-parietal region can lead to a violation of the perception of symbols characteristic of the language systems familiar to the patient. The possibility of identifying letters and numbers with the preservation of their writing (symbolic agnosia) is impaired. It should be noted that in pure form alphabetic and digital agnosia is quite rare. Usually, with a wider lesion with the “capture” of the parietal structures themselves, with their function of spatial analysis and synthesis, not only perception is disturbed, but also writing and cheating graphemes. Nevertheless, it is important that this symptom has left-hemispheric localization.
Agnosia on the face, on the contrary, manifests itself in lesions of the right hemisphere of the brain (middle and posterior regions of the brain). This is a selective gnostic defect, it can occur in the absence of subject and other agnosias. The degree of its severity is different: from a violation of memorization of persons in special experimental tasks, through the failure to recognize familiar faces or their images (photos) to the non-recognition of oneself in the mirror. In addition, a selective violation of either the facial gnosis itself or the memorization of persons is possible. What is the specificity of the "face" as a visual object compared to the subject? It seems to us that the perception of a face is, firstly, determined by very subtle differentiations of the holistic object ("faces with unclear expression") with the similarity of the main features (2 eyes, mouth, nose, forehead, etc.), which are usually not subject to analysis, if the face is all right. Interpretation of a violation of the facial gnosis due to the deficiency of the holistic perception of the object is confirmed by the data on the difficulties of playing chess that occur in patients with lesions of the right hemisphere.Patients who have previously played chess point out that they cannot assess the situation on the chessboard as a whole, which leads to disorganization of this activity. Secondly, the perception of a person always contains the contribution of the individual perceiver, who sees something personal and subjective in the person, even if these are portraits of famous people. The specificity of the perceived person and in its unique integrity, reflecting the individuality of the "sample", and in the attitude of the perceiver to the original. We have already mentioned above the role of the right hemisphere in direct, sensory processes, its “semantic” function. At least on these grounds, it becomes clear the breakdown of the function of perception of persons with the defeat of the right hemisphere of the brain.
The least studied form of visual perception disorder is color agnosia. However, to date, some data have been obtained on color perception disorders in the lesion of the right hemisphere of the brain. They are manifested by difficulties in differentiating mixed colors (brown, purple, orange, pastel colors). In addition, we can note a violation of the recognition of color in a real subject as compared with the preservation of recognition of colors shown on individual cards.
In conclusion of the description of syndromes of visual perception disorder, it should be said that, despite their rather subtle analysis in the clinical neuropsychological aspect, there are enough "white spots" in this area, the main of which is the determination of factors whose violation in local brain lesions leads to the formation of various disorders of visual perceptual activity.
In the anatomical structure of the parietal lobes of the brain in terms of their functional role to ensure higher mental functions, there are three private zones represented by the upper parietal region, the lower parietal region, and the temporal parietal-occipital subregion (A.R. Luria, 1969).
The upper and lower parietal regions border the postcentral zone of the brain, which is the cortical center of the skin-kinesthetic analyzer (the zone of general sensitivity). It should be noted that the lower parietal region is adjacent to that region of the postcentral zone, which provides a central representation of the extra- and interoceptors of the hands, face, and speech articulatory organs. "Accordingly, this area is related to the integration of generalized and abstract forms of signaling that are associated with subtle and complexly differentiated subject and speech actions that require a completely developed system of orientation in the surrounding space" (A.R. Luria, 1969. P. 49).
The temporal-parietal-occipital subregion (SRW) constitutes the transition region between the auditory, kinesthetic and visual zones of the cortex, ensuring the integration of these modalities. It unites all leading modalities in mental reflection, provides complex syntheses in the subject and speech types of human activity, in particular, the analysis and synthesis of spatial and "quasi-spatial" parameters of reflected objects. In general, in a normally functioning brain, the whole complex of parietal structures, together with their switching systems and connections between themselves and with subcortical instances of analyzers, work as one complexly differentiated whole.
a) Syndrome violation of somatosensory afferent syntheses.
This syndrome occurs when lesions of the upper and lower parietal regions bordering the postcentral area of the brain and constitute the secondary sections of the skin-kinesthetic analyzer. The basis of the formation of its constituent symptoms is a violation of the synthesis of skin-kinesthetic (afferent) signals from extra- and proprioceptors. In this regard, in the center of this syndrome are two groups of disorders: tactile (tactile) agnosia and afferent apraxia and aphasia.
Tactile agnosias include symptoms of impaired tactile perception of objects and their properties. Despite the fact that these disorders may occur in the absence of visible disorders of surface sensitivity and deep muscular-articular feeling, there is every reason to believe that defects in perception are associated with impaired sensory syntheses of simultaneously or sequentially perceived groups of stimuli. A.R. Luria pointed to the legitimacy of establishing analogies between visual and tactile agnosia, seeing in their basis a single mechanism, specifically manifested within the framework of visual or tactile modality.
Astereognosis refers to tactile agnosias (the impossibility of identifying the object as a whole with the perception of its individual characteristics). When feeling an object (key, pen, wristwatch, match, spoon, etc.) inserted into the patient’s right or left hand, one can see obvious difficulties that the patient often tries to overcome by connecting the second hand to the identification process. Astereognosis usually occurs when palpating the hand, contralateral to the lesion. However, with local foci in the parietal regions of the right hemisphere, astereogenesis can also manifest itself in the ipsilateral arm, which is particularly clearly seen in the tasks of identifying objects on the Segen board.
Tactile agnosias can extend to the determination of individual properties of an object: shape, size, weight, material from which it is made. A particular variant of tactile agnosia, characteristic of lesions in the left parietal region, is dermoalexia: the impossibility of perceiving characters (letters, numbers, signs) that are “drawn” by the examiner on the patient's arm.
Currently, it has been established that in lesions of the left hemisphere, violations of tactile sensitivity and tactile gnosis occur only in the contralateral (right) hand, while the defeat of the parietal regions of the right hemisphere leads to a violation of these functions and in the ipsilateral (left) hand. This fact testifies to the leading role of the parietal regions of the right hemisphere in the integration of afferent signals in the field of general sensitivity.
This assumption is confirmed by the symptoms of somatogenosis impairment (body pattern), which appear in the overwhelming majority of cases with the right-sided localization of the pathological process. Violations of the body scheme can be seen not only in the difficulties of directly assessing the location of parts of one’s own body, but also in the appearance of false somatic representations (seeming to the patient a change in the size of the arm, head, tongue, doubling of the limbs, their “alienation” from the subject), as well as ignoring the left half body.
In general, tactile agnosias (however, just like visual ones) have not been studied experimentally enough, their psychological structure and psychophysiological mechanisms remain unclear. However, the assessment of the state of the function of tactile gnosis is significant in diagnostic neuropsychological terms.
No less important in the clinical syndrome of damage to the parietal region are violations of praxis, due to a deficiency of afferent movement of information from receptors located in the locomotor apparatus. Often they manifest themselves in the form of afferent paresis, which develops along a hemitip in the contralateral focus of the lesion of the arm. At the same time, afferent (kinesthetic) apraxia can manifest itself as an independent movement disorder in which they lose their delicate differentiation either in relation to the object or when playing the posture of the fingers of a hand following a given pattern. Particularly affected is the performance of the last sample in the absence of visual afferentation, when the patient is asked to transfer the position of the fingers, as determined by the examiners, from one hand to the other. Such disorders of praxis, as a rule,they are observed in the lesion of the left hemisphere and manifest in both hands, which corresponds to the notion of the leading role of the left hemisphere in the organization of praxis that was affirmed in neuroscience. With right foci, disorders are observed only in the left hand.
Kinesthetic apraxia is also found in other mental functions that have a motor link in their structure. These include letter and speech. A.R.Luria singled out a specific form of aphasia - afferent motor aphasia - due to the difficulties of differentiation in the pronunciation and perception of individual speech sounds related to articulation (b - m; n - d) and words whose pronunciation require subtle differentiations in articulatory motor skills. The latter include words and phrases containing both combinations of several consonant sounds ("tpru", "rafters", "shipwreck"), and their repeated repetition in the structure of the utterance ("serum from under yogurt", "from the tramp of hoofs dust flies across the field ").
b) Syndrome of violation of spatial syntheses.
Syndrome of the lower subtopic lesion in combination of individual symptoms of impaired mental functions is known in traditional classical neurology as “SRW syndrome”. Many clinicians and researchers in it were allocated such components as disturbances of orientation in space, defects in spatial orientation of movements and clearly spatial actions (constructive apraxia), agraphia, acaculia, digital agnosia, speech disorders ("semantic aphasia", "amnestic aphasia"), violation of logical operations and other intellectual processes.
A.R.Luria, using the method of syndromic analysis, requiring the release of a syndrome-generating radical, and relying, firstly, on the clinical picture of the lesion of the SRW zone and, secondly, on its structural and functional characteristics, built this syndrome in the logical unity of all the various disturbance phenomena various mental processes.
The SRW area provides the factor of visual spatial and “quasi-spatial” analysis and synthesis necessary for the most complex and complete reflection of the external world. Having developed the concept of spatial perception based on the joint work of the auditory, visual, kinesthetic and vestibular analyzers, and summarizing the data obtained by other researchers on the formation of spatial orientation in ontogenesis, А.R. Luria points out that the most distinct forms of spatial orientation disorder occur in cases where the cortex is affected, ensuring that all analyzers work together.
Distinguishing between visual and "quasi-spatial" analysis and synthesis, A.R. Luria had in mind, on the one hand, the subject’s reflection of the actual spatial characteristics of the external world (visual space), on the other, the verbal designation of spatial coordinates (top-bottom, right-left, front-rear, above-below), and also (and in particular, logical relations that require for their own understanding the correlation of the elements contained in them in some conditional, not visual space (quasi-space). The latter include specific grammatical structures, the meaning of which is determined by the endings of words (father’s brother, brother’s father), ways of arranging them (dress touched the oar, paddled the dress), pretexts reflecting the development of events in time (summer before spring, spring before summer),the discrepancy between the actual course of events and the order of words in the sentence (I had breakfast after reading the newspaper), etc.
It is important here that the “quasi-spatial” constructions do not have direct visual analogs, but are presented in the form of logical relations, which nevertheless require comparison of the elements contained in them in a certain conditional space.
Among the functions that include quasi-spatial components are operations with numbers and intellectual processes. Understanding the number associated with a rigid spatial grid of placing the bits of units, tens, hundreds (104 and 1004; 17 and 71), operations with numbers (counting) are possible only when the number and the "vector" of the operation are kept in memory (addition-subtraction; multiplication -division). The solution of arithmetic problems requires an understanding of the conditions containing logical comparative constructions (more-less by so many, many times, etc.).
Modern ideas about the semantic organization of speech also allow us to speak of a quasi-spatial radical, which determines the interrelation and interposition of words and concepts in the lexical system of the language - in the form of a network of meanings, semantic schemes or fields. In this connection, the actualization of concepts from an individual memory implies an appeal to a certain “place” in a spatially organized system of their storage.
All of the above allows us to understand why a complex syndrome of disorders occurs in the lesion of the SRW zone, affecting a wide variety of mental processes, combined, however, by the fact that in each of them there is a factor of operation with spatial characteristics of information, real or conditional.
With the defeat of the solid radioactive waste zone there are violations of orientation in the objective space. Patients forget familiar traffic routes, cannot correctly navigate in their own apartment, cannot find their ward in the hospital.
In special tasks, there are clearly difficulties in drawing a plan for a hospital ward, in drawing (or identifying) a geographic map, in perceiving or arranging the hands on the "blind" clock. Distinct defects can occur when updating from the memory of representations in cases of drawing (cube, table, house, person), including when drawing from a sample.
When performing movements involving a spatial component (samples of the Head), patients confuse the left and right hands, as well as the left and right half of the body; can not reproduce the position of the back of the hand or palm in a given plane.
In special graphic samples that require mental turning over of a figure during drawing, there are distinct difficulties in joining its elements, in their simple orientation. Similar difficulties arise when laying out a figure from the sticks, when folding the cubes of the Coos or the Link cube (constructive apraxia).
A letter is broken under dictation or writing off of letters in connection with a violation of the actualization of spatially oriented elements of a letter, the difficulty of differentiating perceived letters in a correct or mirror image.
Counting operations suffer in the link of understanding the meaning of a number due to defects associated with the disintegration of its discharge structure. The task to write the number is performed by a mirror (17 - 71), or with the discharge of digits (1004 - 1000 and 4). With a well-understood understanding of the number, a defect in the count can be observed when performing actions with numbers, where patients have difficulties in going through a dozen. So, subtracting 31–7 and getting the result 30–7 = 23, the patient does not know where exactly the remaining unit should be put aside, right or left. So, the symptom of acalculia got its psychological qualification in connection with the defeat of the SRW zone.
In the same syndrome, as a rule, speech disorders are present, referred to as semantic aphasia and amnesic aphasia.
Semantic aphasia is a speech disorder characterized by a deficiency in the impressive component of speech activity, i.e. in the understanding of speech addressed to the patient. At the same time, the understanding of either speech constructions describing real spatial relations is disturbed - draw a triangle "to the right", "to the left", "above", "below" from the cross, or logical-grammatical structures that require an assessment of the spatial relationships between objects.
Amnestic aphasia is a speech disorder, which consists in the violation of the nominative function of speech. Patients find it difficult to update the word-names for the presented object. Violations of naming can manifest themselves in lengthening the latency, in replacing a nomination by defining the function of an object or showing its purpose, in paraphasias, indicating a search for a word in the system of related meanings or grammatically similar words. So, the patient described by A.R. Luria, to the question "where are you?", Answered: "... in this ... as her ... in school, no ... in ... the police, ... no ... in this. .. Red Cross ... in the hospital. " It should be noted that usually in these cases the hint helps the patient very quickly and easily.
Naturally, the violation of the nominative function of speech can not be reflected in the spontaneous speech of patients. However, the safety of the patient’s criticality, his understanding of his inconsistency allows him to find workarounds when constructing a statement, avoiding difficult or difficult speech constructions for him.
It remains to add to the aforesaid about the syndrome of SRW that there are grounds for differentiating left-sided or right-sided lesions, as well as their medial or lateral localization.
The visually-spatial gnosis suffers with a lesion of the SRW zone in both the left and right hemispheres of the brain. However, dysfunction of the right hemisphere reveals a violation of the perception of real space. In tasks for drawing a scheme corresponding to a geographic map, this is manifested when the visual situation of the locations of points is reproduced (Moscow-Leningrad, the Black and Caspian Seas). The defeat of the left hemisphere leads to a violation of spatial codes formed in the learning process and based on speech (symbolic) means. At the same time in the geographic map violations are found in the arrangement of patients with a coordinate system.
In the visual-constructive activity, there are also lateral differences that are easy to detect in samples for drawing (or copying) various objects. It is important to evaluate not only the final result of the performance of a visual-constructive task, but also the dynamic characteristics of the process itself. In addition, significant differences occur when drawing (copying) real objects (house, table, person) and schematic images (cube or other geometric constructions).
In the process of drawing (copying), patients with a lesion of the SRW area of the right hemisphere of the brain perform a drawing, depicting first its individual parts and only then bringing it to the whole. In the case of left hemisphere foci, visual-constructive activity takes place in the opposite direction: from the whole to the details. At the same time, for patients with a lesion of the right hemisphere, there is a tendency to draw realistic parts of the drawing (hair, human collar, crossbars at the table, curtains, porch at home, etc.), and for left-hemispheric patients - to draw schematic images. When evaluating the dynamic features of the activity in drawing tasks, it is necessary to pay attention to such signs as slowness of execution, dashed character of lines,the location of the picture on the right half of the sheet by patients with focal lesions of the posterior parts of the right hemisphere.
It was said above that, regardless of the side of damage to the SRW zone, one can see spatial errors in the figure. However, not only their nature (topological or projection) is different. With right-sided foci, visual-constructive activity suffers more deeply, as evidenced by the violation of the integrity of the replicated or self-depicted figure. Often, the details are taken out of the contour, "attached" to it in random places. Quite often, such structural errors are observed as the unclosed shape, the violation of symmetry, proportions, the ratio of part and whole. The presence of the sample not only does not help patients with a lesion of the right hemisphere (as opposed to left-hemispheric), but often makes it difficult and even disorganizes the visual-constructive activity.
Finally, violations of the visual-constructive activity caused by the right-hemispheric localization of the pathological process are most clearly and distinctly manifested when the medial location of the focus, where they constitute the central, predominant group of symptoms in the general syndrome, comes to the fore. When laterally located foci in the right hemisphere, disorders of visual-constructive activity are present among other symptoms, along with them. This condition is much less manifested in the defeat of the SRW zone in the left hemisphere of the brain.
Counting operations also suffer in different ways with different lateralization of the pathological process. Genuine acalculia, caused by a violation of the digit capacity in the structure of numbers and operations with them, occurs mainly in the defeat of the left hemisphere. Right-brain pathology leads to errors in the automated account (multiplication table) or to errors in its most automated links (within a dozen with a correct transition after a dozen). For example, when subtracting from 100 to 7: 93, 86, 79, 71, 64, 57, 52, etc. On the whole, the syndrome of the lesion of the SRW zone of the right hemisphere is more prominent; these disorders are presented (as well as visual-constructive) with the medial location of the pathological process.
Disturbances of speech and related processes (writing, reading) occur predominantly in left brain cerebral insufficiency. Here you can see both of the above forms of aphasia, agraphia and alexia. However, the defeat of the subdominant hemisphere can lead to the emergence of a number of “speech” symptoms, which include: difficulties in understanding the verbally presented visual-spatial relations of the type “above-below”, “right-left”. In addition, with right hemisphere foci, there are gaps and replacements of stressed vowels in words.
The spatial organization of movements is disturbed mainly in the left-sided localization of the pathological process and does not depend on which hand performs the given movement.
Thus, the state of mental functions in the defeat of the entire parietal system of the brain is characterized by a violation of praxis, tactile gnosis, somatognosis, optical-spatial perception, visual-constructive activity, speech and related processes, counting at various levels of realization of these functions. The basis of these defects is the violation of two factors: somatosensory and spatial (and quasi-spatial) analysis and synthesis. However, it cannot be excluded that the parietal regions of the brain also provide other factors in the structure of mental activity associated with a higher level of integration and providing "synthesis of syntheses." This assumption is supported not only by the massiveness of the parietal syndrome in the symptom complex, a wide range of impaired functions,but also the disintegration of such highly integrated levels of mental reflection as the integrity of perception (body diagram, visual-constructive activity), visual-effective thinking and, as recent studies show, individual memory of the past, organization of individual experience and active appeal to it. This assumption is confirmed in the neuropsychological study of the impairment of mental functions in Alzheimer's disease, where the atrophic process, affecting mainly the parietal structures, causes deep mnestic-intellectual disorders.organization of individual experience and active appeal to him. This assumption is confirmed in the neuropsychological study of the impairment of mental functions in Alzheimer's disease, where the atrophic process, affecting mainly the parietal structures, causes deep mnestic-intellectual disorders.organization of individual experience and active appeal to him. This assumption is confirmed in the neuropsychological study of the impairment of mental functions in Alzheimer's disease, where the atrophic process, affecting mainly the parietal structures, causes deep mnestic-intellectual disorders.
The temporal parts of the brain, representing a system related to the hearing analyzer, are characterized, like other modal-specific structures, by the presence of primary and secondary zones. At the same time, the structure and functions of the temporal parts of the brain are quite complex, they include the so-called extra-nuclear zones and provide not only the actual auditory analysis and synthesis, but also other forms of mental reflection. It should also be noted that the medial surface of the temporal lobes of the brain is part of the limbic system, which is involved in the regulation of the sphere of needs and emotional processes, which is included in the processes of memory and provides the activation components of the brain. A special place in the structure and function of the temporal areas is occupied by areas adjacent to the convexital parietal-occipital areas.The complexity of the structure and function of the temporal systems is determined by the variety of their connections with other parts of the cortex and subcortical structures.
All of the above causes a variety of symptoms of impaired higher mental functions in the defeat of various parts of the temporal region and related not only to acoustic-perceptual functions. Currently, there is every reason to highlight the following syndromes of lesion of the temporal structures: lateral, medial and basal in the aspect of inter-hemispheric asymmetry and inter-hemispheric interaction.
Assessing the function of the secondary divisions of the temporal cortex, A.R. Luria states that they "play a decisive role in the differentiation of both complexes of simultaneously presented auditory stimuli, and successive series of pitch or rhythmic sound structures" (A.R. Luria, 1973. p. 150).
With the defeat of the secondary sections of the temporal region, the syndrome of acoustic, acoustic agnosia in speech (left hemisphere) and non-speech (right hemisphere) spheres is formed.
Speech acoustic agnosia is well described in a number of fundamental works as sensory aphasia, which is based on the violation of phonemic hearing, a factor that provides a differentiated analysis of sense-differentiating speech sounds. The degree of severity of the discernment of speech sounds can be maximal (the differentiation of all speech sounds is disturbed), medium (the discernment of close phonemes is disturbed) and minimal (if the analysis of phonemes is preserved, there is a defective perception of word pairs that differ only in one phonemic attribute, as well as words rarely used or complex in sound composition).
Despite the fact that the central symptom is a disturbance in listening comprehension, the speech deficit is systemic and is found not only in the impressive, but also in the patient's expressive speech, which in the most pronounced variants of the syndrome has the character of "verbal okroshka." The speech of such patients represents a set of syllables, as well as separate speech constructions such as introductory words, interjections and emotional exclamations. It is important to note that at the same time the expressive components of speech (intonation, gestures, facial expressions, focus on dialogue) can remain intact.
In milder cases of dysfunction of the secondary departments of the temporal region, a violation of understanding manifests itself in the phenomenon of “alienation” of the meaning of a word when its sound membrane is reproduced correctly, and in expressive speech there are difficulties in choosing words when constructing a statement, a violation of the nominative function of speech. In samples for naming objects that are visually presented, patients have difficulty in updating the name of the object, which are characterized by either a lengthening of the latent period when selecting the desired name, or literal paraphasias, i.e. replacing the naming word with another similar to the one you are looking for.
It has already been said about the violation of the nominative function of speech in amnesic aphasia in the syndrome of destruction of the SRW zone. The technique, which allows us to differentiate the difficulties of naming in amnesic and sensory aphasia, is a hint to the patient by saying to the inspectors the initial sounds of the word. The fact that the violation of the nomination in the structure of the temporal syndrome is connected with the search for the exact sound image of the word is indicated by the need for a very deep clue, often exciting the entire sound row in a given word, except for the ending. And even such a deep hint does not always help the patient, provoking him to paraphasia or agrammatism. In contrast, with amnesic aphasia, the hint helps "immediately."
The so-called verbal deficit affects the processes of discursive thinking due to difficulties in understanding and comprehending verbal material. The process of understanding when reading is disturbed. A dictation letter may be especially disturbed due to a defect in the analysis of the sound composition of words.
As mentioned above, the sensory-speech defect is, according to most authors, strictly lateralized in relation to the left hemisphere of the brain. Recently, however, there is evidence that the right hemisphere contributes to the process of perception of speech stimuli, but not at the level of analysis of the linguistic characteristics of speech sounds, but at the level of acoustic phonetic features (Yu.V. Mikadze, B.S. Kotik, 1962 In the book of A.R. Luria and modern neuropsychology).
Right-sided lesions of the secondary divisions of the temporal region are characterized by defects in acoustic analysis and synthesis in the non-speech sphere. These include a violation of the identification of household noises, a violation of the perception and reproduction of melodies (expressive and impressive amusia), a violation in the identification of voices according to hearth, age, familiarity, etc.
Among the functions provided by the joint work of the temporal divisions of the right and left hemispheres of the brain is the acoustic analysis of rhythmic structures: the perception of rhythms, their retention in memory and reproduction along the sample. As is known, the so-called auditory-motor coordination is used to assess the state of this function. It seems to be not accidental that the designation of A.R. Luria of this sample, where the gnostic and motor link are inseparably connected and united. The motor component is present not only at the stage of actual performance, but is also included in the perception process (Korsakov, Moskovichiute, 1965), as well as at the stage of rhythms reproduction, the participation of an acoustic link is necessary (extracting from the memory a stimulus series and auditory control aimed at adequate actualization given rhythmic structure).We specifically place here a place for hearing-motor coordination, since recently in the practice of neuropsychology they began to be called "breakdown on rhythms" with an emphasis on the acoustic-gnostic component in this activity. It is necessary to emphasize that the so-called acoustic analysis of rhythms, the activity is much more complex, not only because of the deep connection with the motor system, but also with the broader and more complex complex of rhythmic and oscillatory processes in the body and the nervous system, which is regulated, including phylogenetic subcortical structures of the brain. Obviously, therefore, violations of the performance of this test are quite variable with different localization of the pathological process, and the complete neuropsychological qualification of these disorders is still waiting for its systematic study.since recently in the practice of neuropsychology they began to be called "breakdown on rhythms" with an emphasis on the acoustic-gnostic component in this activity. It is necessary to emphasize that the so-called acoustic analysis of rhythms, the activity is much more complex, not only because of the deep connection with the motor system, but also with the broader and more complex complex of rhythmic and oscillatory processes in the body and the nervous system, which is regulated, including phylogenetic subcortical structures of the brain. Obviously, therefore, violations of the performance of this test are quite variable with different localization of the pathological process, and the complete neuropsychological qualification of these disorders is still waiting for its systematic study.since recently in the practice of neuropsychology they began to be called "breakdown on rhythms" with an emphasis on the acoustic-gnostic component in this activity. It is necessary to emphasize that the so-called acoustic analysis of rhythms, the activity is much more complex, not only because of the deep connection with the motor system, but also with the broader and more complex complex of rhythmic and oscillatory processes in the body and the nervous system, which is regulated, including phylogenetic subcortical structures of the brain. Obviously, therefore, violations of the performance of this test are quite variable with different localization of the pathological process, and the complete neuropsychological qualification of these disorders is still waiting for its systematic study.with an emphasis on the acoustic-gnostic component in this activity. It is necessary to emphasize that the so-called acoustic analysis of rhythms, the activity is much more complex, not only because of the deep connection with the motor system, but also with the broader and more complex complex of rhythmic and oscillatory processes in the body and the nervous system, which is regulated, including phylogenetic subcortical structures of the brain. Obviously, therefore, violations of the performance of this test are quite variable with different localization of the pathological process, and the complete neuropsychological qualification of these disorders is still waiting for its systematic study.with an emphasis on the acoustic-gnostic component in this activity. It is necessary to emphasize that the so-called acoustic analysis of rhythms, the activity is much more complex, not only because of the deep connection with the motor system, but also with the broader and more complex complex of rhythmic and oscillatory processes in the body and the nervous system, which is regulated, including phylogenetic subcortical structures of the brain. Obviously, therefore, violations of the performance of this test are quite variable with different localization of the pathological process, and the complete neuropsychological qualification of these disorders is still waiting for its systematic study.activity is much more complicated not only because of deep connection with the motor system, but also with a wider and more complex complex of rhythmic and oscillatory processes in the body and nervous system, regulated, including the more subcortical structures of the brain, which are more ancient in the phylogenetic aspect. Obviously, therefore, violations of the performance of this test are quite variable with different localization of the pathological process, and the complete neuropsychological qualification of these disorders is still waiting for its systematic study.activity is much more complicated not only because of deep connection with the motor system, but also with a wider and more complex complex of rhythmic and oscillatory processes in the body and nervous system, regulated, including the more subcortical structures of the brain, which are more ancient in the phylogenetic aspect. Obviously, therefore, violations of the performance of this test are quite variable with different localization of the pathological process, and the complete neuropsychological qualification of these disorders is still waiting for its systematic study.therefore, violations of the performance of this test are quite variable with different localization of the pathological process, and the complete neuropsychological qualification of these disorders is still waiting for its systematic study.therefore, violations of the performance of this test are quite variable with different localization of the pathological process, and the complete neuropsychological qualification of these disorders is still waiting for its systematic study.
Before proceeding to the analysis of rhythmic structures reproduction disorders, let us note that the following characteristics are subject to assessment: the volume of the quantitative structure of the rhythmic series (how many beats in the rhythmic cycle), the complexity of the structure (simple packs of beats, accented rhythms, dual rhythmic cycles, etc.) and reproduction by sample and by instructions. It is also important that the perception of a rhythmic series is always the perception of a complete structure, regardless of the complexity or simplicity of its internal organization.
With the defeat of the left temporal region, acoustic analysis and synthesis of the internal structure of the rhythm are primarily affected; therefore, the more complex (accented, double) the series is to be memorized and reproduced, the greater the likelihood of errors in its implementation, and not only in the execution of the pattern, but also according to the instructions. Estimation of the volume of the rhythmic cycle at the same time protects the rough, although it may be characterized by instability. And yet, even the erroneous reproduction of rhythms with left hemispheric lesions shows that the stimulus material is reflected by the patient as an integral structure.
In contrast, with right-sided foci, the perception of the structural formation of a rhythmic cycle as a whole is primarily disturbed. This is manifested in a pronounced violation of the rhythmic structure assessment by the type of narrowing the volume of perception - a disorder specific to the lesion of the right hemisphere, including with respect to acoustic stimuli. This is also indicated by the presence of dissociation between the reproduction of simple unstructured and structured rhythmic series. Structured packs of rhythms are better reproduced than simple ones. Interestingly, the reproduction of rhythms according to the instructions in patients with right-sided foci in the temporal region is often replaced by the actualization of the undifferentiated series,which also makes it possible to suggest the difficulty of forming a reproducible series of tapping as an integral structure.
Thus, the lesion syndromes of the secondary areas of the auditory analyzer, generally characterized as acoustic agnosia, have distinct signs associated with lateralization of the lesion. The left hemisphere is manifested by impaired speech and related processes (sensory aphasia), as well as impaired perception and reproduction of rhythmic structures. Right - violation of perception of non-verbal acoustic material. It should be noted that by now there is an accumulation of facts working in favor of the concept of interaction of the hemispheres in both verbal and non-verbal auditory gnosis, which are still at the level of experimental research and are not included in the range of diagnostic neuropsychological clinical data.
One of the main features of the auditory analyzer, especially significant for understanding the nature of speech disorders and distinguishing it from other analyzer systems, in particular, visual, is associated with the specifics of the organization of acoustic information, the perception of which requires the translation of successively received stimuli as a sequence of sounds into a simultaneous scheme.
Thus, the perception of the sound series is based not only on the analysis of individual elements of the acoustic flow, but equally to keep all its links in memory. In this connection, it becomes clear that there are devices in the acoustic perception system that retain the entire sequence of sounds in memory to understand the meaning of nonverbal acoustic stimuli or the meaning of the perceived utterance. With the defeat of these devices occurs the syndrome of acoustic-mnestic aphasia (left hemisphere) and impaired auditory nonverbal memory (right hemisphere of the brain).
In the center of the syndrome of acoustic-mnestic aphasia, there are impaired hearing-speech memory, i.e. defects in memorization of verbal material presented by ear, with the possibility of reproducing the same stimuli presented visually. In fact, we are talking about modal-specific memory impairment within this analyzer. They manifest themselves in a narrowing of the volume of direct reproduction significantly below normal. So, upon presentation of a series of 4 words, the patient reproduces 1-2 words. It is characteristic that, as a rule, the first or last elements of the series are reproduced, i.e. clearly expressed "edge factor". Similar difficulties (narrowing the volume of reproduction) can be seen when memorizing phrases and stories. An important diagnostic criterion is the absence of an increase in
продолжение следует...
Часть 1 Major neuropsychological syndromes with local brain lesions
Часть 2 - Major neuropsychological syndromes with local brain lesions
Comments
To leave a comment
Neuropsychology
Terms: Neuropsychology