Neuropsychological syndromes in vascular lesions of the brain

In the previous chapter, neuropsychological syndromes and symptom complexes describing the state of higher mental functions under conditions of destruction of brain tissue and the existence of a topically localized lesion were described.
In recent years, an independent, new, specialized field of clinical neuropsychology has emerged, connected with the study of impaired mental functions in vascular pathology. This area of ​​research has a number of features due to the uniqueness of the vascular clinic, and, accordingly, correlated with it peculiarity of syndromes of impaired mental processes. Testing a neuropsychological approach in a clinic for vascular pathology of the brain showed an extremely high sensitivity of neuropsychological tests not only with respect to the vascular pathology itself, but also with respect to such hemodynamic manifestations, such as changes in blood flow in any of the vessels.
The clinical manifestations of the actual vascular lesions of the brain include arterial and arteriovenous aneurysms, vascular spasm of the brain (as an independent violation of hemodynamics and as a hemodynamic reaction to hemorrhage), ischemic strokes due to vascular thrombosis, transient disturbances of cerebral circulation and dyscirculatory encephria, and circulatory disorders, as a result of vascular thrombosis. other) changes in the cerebral vessels.
In any of the following clinical syndromes of cerebral blood circulation disorders, a complex complex of symptoms of mental function disorder arises, which differs in structure from the syndromes of local brain damage of a tumor or traumatic genesis. These differences and the complexity of the neuropsychological syndrome itself are due to a number of reasons.
First, here we are dealing with a violation of functions specific to a group of brain structures that receive blood supply from a single vascular pool. For example, the middle cerebral artery receives blood supply to the parietal, temporal and posterolateral convexital parts of the brain, therefore the complex of disorders associated with the pathology in this vascular basin may include symptoms from all of the listed brain areas. This example shows that the classification of syndromes that has developed in the clinic of neoplastic brain lesions is not fully adequate for determining the lesion area in the case of vascular pathology.
In this regard, one of the main tasks of clinical neuropsychology in the vascular clinic is the study of neuropsychological syndromes caused by circulatory disorders in the basins of various cerebral vessels: the anterior cerebral artery, the middle cerebral artery and the posterior cerebral artery.
Secondly, circulatory disorders can have various pathogenetic mechanisms. The blood flow can either stop altogether due to vessel occlusion (thrombosis, thromboembolism), or decrease with spasms (acute condition), stenosis or "stealing" of any blood supply zone due to an abnormal redistribution of blood flow to such vascular malformation as arterio-venous aneurysm, or direct arteriovenous shunting. Thus, in these cases, the neuropsychological symptoms will be topically related to the area of ​​the brain that does not receive sufficient blood supply. At the same time, the fact that short-term spasm or a robbery can occur in an unchanged vessel, while stenosis is caused by a morphological change in its wall, is of particular importance.
Thus, the second task of neuropsychology in the clinic of vascular disorders is to isolate and qualify the symptoms of impaired mental functions due to the causes of the impaired cerebral hemodynamics.
Thirdly, the clinical symptom complex with vascular lesions of the brain consists not only of local symptoms associated with the pathology of a particular vessel and area that is supplied with blood, but also with a number of symptoms caused by various dysgemias in other vessels of the brain. The fact is that the processes of self-regulation in the vascular system are extremely dynamic and include various compensatory mechanisms. This leads to the simultaneous existence of zones of compensated, subcompensated and decompensated blood circulation in the brain, which, in turn, creates a large mosaic of symptoms.
As a result, neuropsychology faces another challenge - the need to isolate impaired mental functions that may be associated with altered blood supply conditions of the whole brain or its individual zones.
Under the conditions of simultaneous occurrence of various pathological processes that are dynamic in nature and lead to mosaic and sometimes diffuse impairments of mental functions, the search for their clinical and morphological correlates is extremely difficult and often cannot be obtained only by comparing clinical and psychological research data and computer data. tomography and angiography. To address these issues, it is necessary to involve the whole complex of objective methods, including data on the state of regional cerebral blood flow, and information on the dynamics of mental disorders after operations on cerebral vessels. A special role in solving this task is currently acquired by endovascular intervention aimed at normalizing blood flow and allowing not only to interpret the disturbance of mental processes due to local manipulations on individual branches within the vascular basin, but also to trace changes in neuropsychological symptoms in the dynamics of endovascular effects during sequential occlusion of various vascular branches involved in the formation of brain pathology.
At the same time, despite these difficulties, the vascular clinic in the study of the brain organization of mental functions has several advantages, which consist in the fact that, firstly, the contingent of patients is usually young people and, secondly, with vascular there are no dislocation and cerebral pathologies (with the exception of the acute period of cerebral circulation disorders) disorders characteristic of the tumor and traumatic etiology of the pathological process.
It should be noted that in relation to the study of cerebral symptoms and their role in the general neuropsychological syndrome, the clinic of vascular lesions of the brain provides unique opportunities for research.
1. Cerebral symptoms and their dynamics in vascular pathology
brain
The occurrence of cerebral symptoms associated with an acute period of development of vascular disorders, the most pronounced picture of which can be seen in subarachnoid hemorrhage (SAH). The isolation of cerebral symptoms from a complex symptom complex is possible: 1) when comparing data from a neuropsychological study of patients with SAH from saccular aneurysms with groups of patients who have similar aneurysms but are in the so-called "cold" period; 2) in terms of tracking changes in neuropsychological symptoms in the dynamics of the release of patients from the acute stage of SAH.
One of the first manifestations of SAH in aneurysm rupture is a loss of consciousness of different duration, however, not all patients experience impaired consciousness. In the group studied by us, disorders of consciousness were observed in 66% of patients with localization of the aneurysm in the right half of the circle of Willis and in 33% of patients with localization of the aneurysm in the left hemisphere of the brain. (To discuss the lateral differences in the formation of this symptom, we turn a little later). When out of unconsciousness, amnesia was detected in 30% of patients. However, this syndrome also occurred in 22% of patients who did not suffer consciousness disorders in the acute stage of SAH. These data do not allow unambiguously to associate the occurrence of memory impairment during SAH with the presence of impaired consciousness. However, there is reason to talk about the connection of the formation of mnestic disorders with the duration of loss of consciousness, since in patients with short-term loss of consciousness, amnesia syndrome was observed in 33%, and in patients with a long period of unconsciousness - in 54% of cases.
After getting out of the unconscious state, all patients showed a decrease in the level of wakefulness in the form of general inhibition, drowsiness, lack of activity and a rapidly advancing exhaustion of mental activity. Starting to perform the tasks correctly, the patients quickly switched to their erroneous fulfillment, and then refused to continue their activities altogether. At the same time, the mental processes were obviously slow, with a high latency when they were included in the execution of instructions, while adynamy increased as the neuropsychological tests continued. There were errors related to the deficiency of the functions of programming activities and monitoring their flow.
Often these disorders were combined with the general condition of the patients, their lack of interest in themselves, their condition, the situation of a neuropsychological examination, and the surrounding. The need and emotional sphere in these patients was manifested in a reduced form, there were no adequate emotional reactions to the failure in carrying out the tasks offered to them. In some patients, general disinhibition, increased motor activity, and distractibility could occur. However, this state of general psychomotor background did not introduce significant changes in the processes of regulation of mental purposeful activity, which remained grossly disturbed.
It should be noted that in various patients, psychic inactivity and reduction of the initiative with varying degrees of severity were manifested in various spheres of mental activity (motor, speech, etc.). It can be assumed that the unevenly expressed deficiency of functions is associated with the local influence of the vascular focus.
Dynamic tracking showed that with a gradual regress of disturbances of the level of wakefulness, the ability of patients to perform simple, separate operations also gradually increased with a continuing deficit in the implementation of more complex, developed activities.
At this stage - the stage of reducing the level of wakefulness and mental activity - disturbances of neurodynamics clearly manifested themselves in the form of pathological inertness of the nervous processes. After completing any motor or graphic task, patients found it impossible to switch to a new instruction and replaced its implementation with an inertly actualized stereotype. The exhaustion developing at the same time aggravated pathological inertness of patients.
Gradually, the level of wakefulness of patients and their activity increased, but there were clear variations in these activity parameters, their instability. The possibility of a correct start in the implementation of more complex programs appeared, but as they were implemented, errors arose, the activity of the patients seemed to "fade out", as a result of which random answers appeared as a form of completing the started task. During this period, the memorization curve of 10 words bore the character of a plateau in patients, there was no increase in productivity in the process of memorization, the same words were inertly reproduced. This indicates a violation of the arbitrary purposeful regulation of the memorization process, the lack of the control function in the process of memorization. At the same time, as a persistent pathological phenomenon, violations of voluntary attention were observed in patients who, even in the final stage of getting out of an acute condition, coped with tasks such as proofreading and Kraepelin counting with difficulty.
The dynamics of the amnesic syndrome shows an increase in its severity in the acute period of SAH compared with the period preceding the latter. The main forming radical in the structure of the mnestic defect was an increased inhibitory rate of the traces of interfering influences, which did not act as a specific sign due to localization and lateralization of the pathology of a particular vascular basin, but as a common symptom for all patients, which makes it attributed to cerebral manifestations correlating with level disorders wakefulness and other disorders characteristic of this period. It should be noted that the degree of manifestation of traces inhibition under conditions of interference in the acute stage of the NAO seemed to overlap the specific signs of memory impairment associated with local manifestations of vascular pathology. This assumption was confirmed by the fact that, as the associated symptoms were reduced from an acute condition and reduced, symptoms of memory impairment acquired specific local characteristics.
It should be noted that the described dynamics of the state of mental functions in different patients had not only different temporal characteristics. Stages of the reverse development of cerebral symptoms in a significant number of cases could proceed in a very hidden, truncated form, and objective registration was not always available. Along with this, other patients demonstrated a developed form and the presence of a cerebral symptom complex and a distinct phased dynamics of its reduction. In the final stage of the patient's exit from the acute condition caused by SAH, cerebral symptoms went to the background in the syndrome of impaired mental functions, giving way to pathological signs associated with local manifestations of vascular disorders.
It was said above that impairments of consciousness with unequal frequency occurred in hemorrhages, depending on the right or left-sided localization of the aneurysm. Lateral differences were also found in the duration of the unconscious state. With the localization of the aneurysm in the left hemisphere of the brain, more than half of the patients were in a state of unconsciousness for a few minutes, only in 25% of patients in this group, the disorders of consciousness continued for a day or more. In contrast, the right-hemispheric localization of the aneurysm in cases of SAH in 72% of patients resulted in a prolonged (more than 12 hours) loss of consciousness and only in 12% of cases in patients of this group did short-term unconscious states occur.
These results indicate that the right and left hemispheres of the brain differ both in the thresholds of sensitivity to the hemorrhagic factor and in their ability to spontaneously restore impaired functions.
Thus, for the acute period of subarachnoid hemorrhage, the following cerebral symptoms are characteristic: impairment of consciousness of varying duration, depth and severity; a decrease in the level of activity in combination with a violation of the dynamics of the flow of mental processes; emotional need disorders; exhaustion, reduced performance, fluctuations in the level of achievements in the performance of tasks, fluctuations in the level of voluntary attention; the instability of the retention of the program of activities, the tendency to simplify it, replacing it with random actions or stereotypes; the presence of changes in the neurodynamic parameters of the brain, manifested in pathological inertness and the development of retroactive inhibition. The latter is especially clearly represented in memory disorders, where the general amnestic syndrome masks the specifics of the mnestic defect associated with the localization of the aneurysm.
All described symptoms appear in individually-typological characteristics, are presented unevenly and with varying degrees of severity in equal patients and at different stages of the reverse development of an acute condition.
It seems to us that the complex of cerebral symptoms described on the SAH model can also be attributed to cerebral disorders included in the structure of the syndrome of impaired mental functions in traumatic and neoplastic brain lesions. The qualitative features of the restoration of brain function after a traumatic brain injury transferred to a patient confirm the validity of such a transfer, especially in severe cases of injury, accompanied by loss of consciousness. With regard to brain tumors, it can be said that, first, cerebral symptoms reach a significant degree only with a combination of massive intracranial hypertension with edema and swelling of brain tissue, as well as with a toxic component in malignant tumors. In addition, the difference between cerebral symptoms of tumor and vascular genesis consists in the opposite dynamics of their development. SAH begin with severe cerebral disorders (and loss of consciousness), followed by their reduction, while with tumors, cerebral disorders develop gradually, reaching consciousness disorders only at later stages of changes in the functional state of the brain.
2. Neuropsychological syndromes in arterial aneurysms.
Arterial aneurysms are one of the forms of vascular pathology, which is characterized by a defect in the vessel wall in the form of its protrusion and gradual stretching. Most often, arterial aneurysms are localized in the area of ​​the Circle of Willis or near it, i.e. on the basis of the brain.
As a rule, the vascular formation is small in size and does not in itself affect the state of the surrounding nervous tissue. Disorders of the brain occur due to rupture of the aneurysm and hemorrhage, which usually proceeds as a subarachnoid, but in some cases the blood can also get into the substance of the brain (parenchymal hemorrhage). A spasm of the vessel carrying the aneurysm is directly related to the rupture of the aneurysm and hemorrhage.
In the period remote from hemorrhage, arterial aneurysms may not be accompanied by a violation of higher mental functions. Together about that and in the "cold" period, a number of patients show neuropsychological symptoms, which is associated both with ischemic changes in the brain substance that developed in the acute period and after it, and with irreversible post-spasmodic changes in the form of a narrowing of the vessel lumen and the formation of the surrounding brain substance the so-called avascular zone.
In connection with the above, it becomes obvious that the neuropsychological symptoms in the clinic of arterial aneurysms are the result of disorders occurring either in a situation of subarachnoid hemorrhage, or as a result of vasospasm, or ischemic foci in the brain tissue.
3. Neuropsychological syndromes of cerebral vasospasm.
Currently, the symptoms of spasm in the basins of the anterior cerebral artery (PMA), the middle cerebral artery (MCA), the internal carotid artery (ICA) and the vertebro-basilar system (IBS) are well studied.
The PMA vascular pool provides blood supply to the medial regions of the frontal and part of the parietal lobes of the brain, the anterior and middle sections of the corpus callosum, the anterior sections of the subcortical structures and the hypothalamus. It is natural to assume that during a spasm in the basin of the PMA, a complex of neuropsychological symptoms may be formed, incorporating pathological phenomena, the origin of which is due to the lack of blood supply to all brain areas united by this vascular basin. It has been shown that a decrease in blood flow in PMA can lead to a variety of disorders from massive syndrome of combined lesions of subcortical-diencephalic structures, corpus callosum and medial regions of the frontal and parietal lobes to almost asymptomatic cases (AR Luria et al., 1970).
Central to the clinical neuropsychological picture of PMA spasm is memory impairment. In their structure, they correspond to the mental disorders described above associated with lesions of the diencephalic-hypothalamic region. Here, too, the mechanism of heightened inhibition of traces by interfering influences is the syndrome-forming radical in the mental defect.
The generalized nature of mental disorders, varying degrees of severity, and the pathological mechanisms of forgetting allow us to associate these disorders with dyscirculatory phenomena in the anterior regions of the subcortical structures and the hypothalamic region. The severity of the mechanism of selectivity of reproduction with gross contaminations and confabulations, slippage when playing into side associations, is most likely due to a change in the functional state of the medial regions of the frontal lobes of the brain.
This is confirmed by new clinical data on the "site" of blood flow disorders within the PMA. If segment A1 was spasmodic, from where the subcortical structures and the hypothalamus receive blood supply, memory disorders are observed in all patients, often reaching the extreme severity of amnestic syndrome. When the spasm of the A2 segment is located after the detachment of the branches supplying the subcortex and hypothalamus from the PMA, memory disorders occur only in 25% of patients and do not reach such a pronounced degree. When combined spasms of A1 and A2 segments, frontal syndrome signs such as a violation of control over the activity, difficulties in programming and a decrease in the regulatory function of speech join the mnestic disorders.
Simultaneously with impaired memory, the neuropsychological syndrome caused by impaired blood flow in the PMA pool is characterized by impaired consciousness in the form of disorientation in time, place, and disease; reducing the criticality of patients; emotional changes characteristic of the lesion of the medial regions of the hemispheres, general inactivity, narrowing of the motivational-need sphere and distinct disturbances in the dynamics of the flow of mental processes. All these symptoms occur on the background of pronounced exhaustion of mental activity, characteristic of patients with vascular pathology, even in periods remote from SAH. In all likelihood, the lack of blood flow, associated with a long spasm of the vessels carrying the aneurysm, limits the ability of the brain to work in a mode that is optimal for full mental activity.
A spasm in the system of the middle cerebral artery (SMA) causes a different picture of neuropsychological symptoms. The MCA supplies the convexital sections of the posteriorly, temporal and parietal lobes of the brain. As a result of dyscirculatory disorders in this pool, the center of the neuropsychological syndrome turns out to be a complex of speech disorders in the form of a mixed form of aphasia combining the symptoms of afferent and efferent motor, sensory and acoustic-mnestic aphasia. At the same time, disorders of dynamic and kinesthetic praxis, disturbance of the spatial organization of movements and symptoms of visual-constructive activity deficiency can be seen. All of these symptoms can occur in various combinations with a predominance of signs of predominant dysfunction of the posterior, parietal, or temporal structures of the brain,but in most cases in case of SMA spasm, all structures involved in the pathological process are those whose blood supply is ensured by the SMA of the left or right hemispheres of the brain. In the neuropsychological syndrome that occurs during MCA spasm, modal-specific memory disorders, corresponding to those brain zones that are combined by this vascular basin, occupy a special place in the absence of proper speech, motor and visual-spatial disorders. In this case, memory impairment, depending on the side of the lesion of the MCA basin, is manifested either by symptoms of a direct (right hemisphere) or delayed reproduction (left hemisphere) reproduction disturbance.In the neuropsychological syndrome that occurs during MCA spasm, modal-specific memory disorders, corresponding to those brain zones that are combined by this vascular basin, occupy a special place in the absence of proper speech, motor and visual-spatial disorders. At the same time, memory impairments, depending on the side of the lesion of the MCA basin, are manifested either by the symptoms of a violation of the immediate (right hemisphere) or delayed reproduction in the conditions of interference (left hemisphere).In the neuropsychological syndrome that occurs during MCA spasm, modal-specific memory disorders, corresponding to those brain zones that are combined by this vascular basin, occupy a special place in the absence of proper speech, motor and visual-spatial disorders. At the same time, memory impairments, depending on the side of the lesion of the MCA basin, are manifested either by the symptoms of a violation of the immediate (right hemisphere) or delayed reproduction in the conditions of interference (left hemisphere).At the same time, memory impairments, depending on the side of the lesion of the MCA basin, are manifested either by the symptoms of a violation of the immediate (right hemisphere) or delayed reproduction in the conditions of interference (left hemisphere).At the same time, memory impairments, depending on the side of the lesion of the MCA basin, are manifested either by the symptoms of a violation of the immediate (right hemisphere) or delayed reproduction in the conditions of interference (left hemisphere).
The spasm of the internal carotid artery (ICA) in its neuropsychological syndrome is almost identical to the disorders arising from spasm of the MCA. This identity becomes clear if we consider that the MCA is one of the branches of the ICA. However, this violation of mental functions may be represented by a lesser degree of severity and completeness of the symptom complex. It can be assumed that impaired blood flow does not capture the entire SMA system, and the collateral circulation largely compensates for dysgemic disorders. This assumption (although the mechanisms of this phenomenon are still unclear) is supported by the fact that the most characteristic of a spasm of the ICA are memory impairment, with signs of a modal-specific defect in the form of a deficiency in memorizing visual-spatial,auditory or kinesthetic information. Even in the combined form, modal-specific memory disorders are quite rarely (no more than in 20% of cases) “summed up” into a single amnestic syndrome, which, if it occurs, manifests itself in a very reduced form and is detected only in sensitized conditions. clinical experimental study (an increase in the amount of memorized material, homogeneous interference). These data indicate that the spasm of the ICA leads to a disruption of the work of the posterior forehead, temporal, and parietal sections only at the mnestic level (unlike the gnostic), i.e. the dysfunction of these areas of the brain is expressed quite gently. Lateral differences in the structure of memory impairment are presented here as in the case of CMA spasm.Even in the combined form, modal-specific memory disorders are quite rarely (no more than in 20% of cases) “summed up” into a single amnestic syndrome, which, if it occurs, manifests itself in a very reduced form and is detected only in sensitized conditions. clinical experimental study (an increase in the amount of memorized material, homogeneous interference). These data indicate that the spasm of the ICA leads to a disruption of the work of the posterior forehead, temporal, and parietal sections only at the mnestic level (unlike the gnostic), i.e. the dysfunction of these areas of the brain is expressed quite gently. Lateral differences in the structure of memory impairment are presented here as in the case of CMA spasm.Even in the combined form, modal-specific memory disorders are quite rarely (no more than in 20% of cases) “summed up” into a single amnestic syndrome, which, if it occurs, manifests itself in a very reduced form and is detected only in sensitized conditions. clinical experimental study (an increase in the amount of memorized material, homogeneous interference). These data indicate that the spasm of the ICA leads to a disruption of the work of the posterior forehead, temporal, and parietal sections only at the mnestic level (unlike the gnostic), i.e. the dysfunction of these areas of the brain is expressed quite gently. Lateral differences in the structure of memory impairment are presented here as in the case of CMA spasm.into a single amnestic syndrome, which, if it occurs, manifests itself in a very reduced form and is detected only in sensitized conditions of a clinical experimental study (an increase in the volume of memorized material, homogeneous interference). These data indicate that the spasm of the ICA leads to a disruption of the work of the posterior forehead, temporal, and parietal sections only at the mnestic level (unlike the gnostic), i.e. the dysfunction of these areas of the brain is expressed quite gently. Lateral differences in the structure of memory impairment are presented here as in the case of CMA spasm.into a single amnestic syndrome, which, if it occurs, manifests itself in a very reduced form and is detected only in sensitized conditions of a clinical experimental study (an increase in the volume of memorized material, homogeneous interference). These data indicate that the spasm of the ICA leads to a disruption of the work of the posterior forehead, temporal, and parietal sections only at the mnestic level (unlike the gnostic), i.e. the dysfunction of these areas of the brain is expressed quite gently. Lateral differences in the structure of memory impairment are presented here as in the case of CMA spasm.These data indicate that the spasm of the ICA leads to a disruption of the work of the posterior forehead, temporal, and parietal sections only at the mnestic level (unlike the gnostic), i.e. the dysfunction of these areas of the brain is expressed quite gently. Lateral differences in the structure of memory impairment are presented here as in the case of CMA spasm.These data indicate that the spasm of the ICA leads to a disruption of the work of the posterior forehead, temporal, and parietal sections only at the mnestic level (unlike the gnostic), i.e. the dysfunction of these areas of the brain is expressed quite gently. Lateral differences in the structure of memory impairment are presented here as in the case of CMA spasm.
At the same time, this group of patients may experience such specific disorders as systemic perseverations in the spasm of the left ICA and the phenomenon of left-sided ignoring in various afferent and efferent systems with aneurysm localization in the right ICA.
A spasm in the vertebro-basilar system (IBS) in the overwhelming majority of cases is accompanied by the development of global modal nonspecific memory disorders of the amnesic syndrome type. With external similarities with mnestic disorders arising from PMA spasm, this syndrome has, as shown by neuropsychological studies, its own characteristics. First of all, the central symptom here is a violation not of delayed in the conditions of interference, but of direct reproduction, and the interference does not generally have a significant negative impact on the productivity of reproduction. These memory disorders act against the background of a violation of orientation, and not so much in time and place as in one’s own personality, reaching even such a degree of severity when the patient is unable to provide information about his profession.family and other individually significant events and facts of their lives, including information about their disease.
Symptoms of impaired spatial functions, visual and acoustic gnosis, which do not reach a sufficient degree of severity, may be added to the phenomena of impaired memory and patient orientation. It should be noted that the neuropsychological syndrome of spasm of the heart disease carries the features of a local right-sided lesion in the parieto-temporal-occipital parts of the brain. VBS provides blood supply to the medial regions of the parietal, temporal, and occipital lobes of the brain, the posterior portions of the subcortical structures, the corpus callosum, and the limbic cortex. Describing the syndromes of local tumor lesions of the brain, we talked about more pronounced pathological manifestations with the defeat of the posterior medial regions of the right hemisphere of the brain as compared with the left. Vascular clinic once again confirms this situation.
Typically, disorders of higher mental functions during cerebral spasm of the brain are unstable and quickly regress after the restoration of blood flow in the vessel. However, a complete regression of neuropsychological symptoms is not always observed, even though the angiographic control shows the restoration of blood flow. In the vast majority of such cases, computed tomography reveals ischemic foci in the tissue of brain areas entering the blood supply zone of a given vessel. In all likelihood, in some cases, spasm and the associated lack of blood supply can lead to irreversible death of nerve cells and fibers.
Finally, in a small group of patients, a narrowing of the vessel lumen on an angiogram can be recorded for a long time after undergoing angiospasm. Obviously, in some cases, as a consequence of the latter, morphological changes in the vessel wall may occur.
In general, the ratio of the functional and morphological in the pathogenesis of spasm and the restoration of the impaired mental functions associated with it is determined by its severity and duration, as well as by the conditions of collateral circulation. The good condition of the collaterals can apparently be explained by the absence of neuropsychological symptoms in the presence of spasm, and, in contrast, the insufficiency of the collateral circulation leads, as a rule, to a massively expressed impairment of brain functions (pathology of the Willis circle plays a special role).
Thus, the spasm of each of the cerebral vessels has its own specific symptom complex. Nevertheless, a common incidence for the clinic as a spasm is the high incidence of memory impairment and emotional personality disorders.
4. Neuropsychological syndromes in arteriovenous aneurysms.
Arteriovenous aneurysms (AVA) are congenital deformities of the vascular system of the brain, consisting of a coil of pathological vessels, where the arteries directly pass into the veins, bypassing the capillary system.
Clinical syndromes in ABA are due to two pathophysiological factors. First, the vascular conglomerate has a local effect on the surrounding brain tissue, including due to hemorrhages from ABA (focal symptoms). Secondly, the presence of ABA leads to a change in hemodynamics due to an abnormal discharge of arterial blood from the blood supplying the vessel to the ABA. At the same time, the latter is functionally disconnected from the nutrition of the cerebral zones vascularized by it, and as a result, subcompensated ischemia is formed in the zone of the vessel “robbed” by the aneurysm and insufficiency of the brain structures that do not receive full blood supply (symptoms of “robbery”).
The presence of these two components in the neuropsychological syndrome is easily objectified with influences aimed at turning off the ABA from the blood supply and normalizing the blood flow. With endovascular shutdowns of the vessel supplying aneurysm or with radical surgical removal of ABA, it can be seen how the restoration of blood supply in the previously “robbed” brain zones leads to a regression of neuropsychological symptoms that occur at a distance from the aneurysm.
Disturbances of mental functions in ABA, as a rule, are expressed non-grossly, with the exception of the acute stages accompanying hemorrhage. Almost not observed paresis and apraxia, agnosia and aphasia, pronounced disorders of memory and consciousness. This distinguishes this form of pathology from the clinical manifestations of spasm or thrombosis in identical vascular basins. At the same time, a directional and thorough neuropsychological examination reveals the symptom complexes associated with both the localization of ABA and the “steal” type of hemodynamics.
Let us describe this on the ABA material localized in the medial or lateral parts of the frontal lobes of the brain, supplying blood from the anterior or middle cerebral arteries, as well as from both of these vascular basins. Examination of patients with AVA in the left and right hemispheres of the brain shows that impaired mental functions are characterized by sufficient diversity and are due to extensive cerebral insufficiency. The severity of disorders only in the first days after hemorrhage can be comparable with tumor or traumatic injuries of the frontal lobes. As the cerebral symptoms due to hemorrhage emerge from the acute state and regress, the mental impairment syndrome is generally manifested by a deficit in dynamic praxis and speech motor skills,intellectual disorders and modal nonspecific dismnesicheskie phenomena. Often, the syndrome includes changes in consciousness and the affective sphere in combination with a partial decrease in spontaneity and activity; in some cases, there are violations of the perception of rhythms. These symptoms manifest themselves differently when the ABA is located in the right or left frontal lobe.
For the left hemispheric localization of ABA, the patient’s orientation in time, place, and disease is characteristic; the presence of impulsivity and inertia in the implementation of mental activity; the difficulty of switching when changing instructions, the de-automatization of movements (without perseverations and stereotypes), mainly in both hands; signs of efferent motor and dynamic aphasia; modal nonspecific memory impairments detected only in clinical and experimental research in the link of delayed reproduction. Intellectual processes reveal a deficit in the implementation of serial tasks that require extensive program execution. Emotional reactions in patients mainly change in the direction of negativism, depression and flattening.
The location of the ABA in the right frontal lobe leads to instability of the orientation in the immediate time (chronognosia), the impossibility of determining the temporal sequence of events according to history, impaired awareness and experience of the disease, decreased activity and intention when performing tasks, difficulties in engaging in activities, lengthening the latent period between taking instructions and its implementation. Patients exhibit emotional monotony and complacency, do not express anxiety about the upcoming operation and anxiety about their future. Dynamic praxis is disturbed in the contralateral side of the localization of the ABA arm.
Speech disorders are characterized by speech disinhibition, uncontrollable word substitutions in spontaneous speech due to semantic similarity with echoria of hardened, simple verbal meanings. Memory defects are modally non-specific in nature, but unlike left hemispheric AVA, they relate to the stage of immediate reproduction (narrowing of the memory volume, difficulty in keeping the order of the elements in a sequence). Intellectual disorders are largely determined by the narrowing of the volume of perception and memory, the loss of the most simple, automated links from the program.
Depending on the medial or lateral location of the vascular conglomerate in the left frontal lobe, one can see a predominance of certain symptoms in the structure of focal AVA syndrome. Dynamic praxis, speech motility, intellectual processes are more often disturbed when ABA is located laterally; emotional-personal sphere and speech initiative - with the medial. Dysfunction of the right frontal lobe does not give grounds for identifying similar differences.
We described the symptom complex of a “local” effect of a vascular conglomerate. What are the symptoms attached to it as a result of stealing of the vascular zone away from ABA? It depends on the system of vessels included in the blood supply to the aneurysm. The stealing of PMA is manifested by dysfunction of the medial structures of the anterior hemispheres, coinciding with the localization of ABA and not making significant changes in the neuropsychological syndrome except for the violation of the kinesthetic basis of movements.
OMA robbery forms the insufficiency of the temporal and parietal systems of the corresponding hemisphere of the brain with symptoms of impaired acoustic gnosis, aural-verbal memory, disintegration of spatial representations and related functions. Since the SMA system receives blood supply from laterally-located ABAs, the total picture of the neuropsychological syndrome is made up of dysfunction of the frontal, temporal, and parietal areas of the brain.
In conclusion, it is necessary to point out one feature of the syndrome associated with the medial localization of AVA in the frontal regions and its blood supply from PMA - the high stability of the neuropsychological syndrome in its structure with a very different degree of its severity.
5. Neuropsychological syndromes with occlusive brain vessel lesions.
The change in the patency of the arterial bed can be both persistent and reversible, and therefore there are various clinical forms of cerebral hemodynamic disorders, which mainly include stenosis and thrombosis. They can be the decisive factor in the formation of mental disorders. It should be borne in mind that the vascular system of the brain has a fairly good self-regulation system that ensures the adequacy of blood circulation to the conditions of brain functioning. In this regard, even more severe lesion - thrombosis - can sometimes not be clinically manifested (with developed collateral circulation), while temporal functional occlusion of the vessel is also possible with stenosis, leading to the appearance of symptoms of impaired brain function.
a) One of the forms of cerebral vascular insufficiency is dyscirculatory encephalopathy (DE), resulting from damage to the cerebral vessels and leading to a disproportion between the needs and possibilities of providing the brain tissue with full blood supply. In neuropsychological terms, the atherosclerotic form of DE is the most well-studied, in which a wide spectrum of symptoms of impairment of higher mental functions is found, which is available, however, in three main symptom complexes. As a rule, the main defect in DE is the lack of visual-constructive activity due to the violation of spatial analysis and synthesis. The second group of symptoms is a violation of the dynamic organization of functions: a decrease in the rate and efficiency of working capacity, instability of attention,insufficiency in the dynamic organization of movements, inertness in intellectual and mnestic processes. The third syndrome in DE is memory impairment to current events, which reveal violations of the immediate and, especially, delayed reproduction, the unproductive learning of 10 words with marked inertia and an early “plateau”. If visual-constructive activity is manifested by a fairly stable deficiency, then the second and third group of symptoms at earlier stages of DE manifests noticeable fluctuations that gradually smooth out in amplitude and become more pronounced at later stages of atherosclerosis, especially in conditions of rapidly approaching exhaustion.The third syndrome in DE is memory impairment to current events, which reveal violations of the immediate and, especially, delayed reproduction, the unproductive learning of 10 words with marked inertia and an early “plateau”. If visual-constructive activity is manifested by a fairly stable deficiency, then the second and third group of symptoms at earlier stages of DE manifests noticeable fluctuations that gradually smooth out in amplitude and become more pronounced at later stages of atherosclerosis, especially in conditions of rapidly approaching exhaustion.The third syndrome in DE is memory impairment to current events, which reveal violations of the immediate and, especially, delayed reproduction, the unproductive learning of 10 words with marked inertia and an early “plateau”. If visual-constructive activity is manifested by a fairly stable deficiency, then the second and third group of symptoms at earlier stages of DE manifests noticeable fluctuations that gradually smooth out in amplitude and become more pronounced at later stages of atherosclerosis, especially in conditions of rapidly approaching exhaustion.the unproductiveness of memorizing 10 words with marked inertia and an early “plateau”. If visual-constructive activity is manifested by a fairly stable deficiency, then the second and third group of symptoms at earlier stages of DE manifests noticeable fluctuations that gradually smooth out in amplitude and become more pronounced at later stages of atherosclerosis, especially in conditions of rapidly approaching exhaustion.the unproductiveness of memorizing 10 words with marked inertia and an early “plateau”. If visual-constructive activity is manifested by a fairly stable deficiency, then the second and third group of symptoms at earlier stages of DE manifests noticeable fluctuations that gradually smooth out in amplitude and become more pronounced at later stages of atherosclerosis, especially in conditions of rapidly approaching exhaustion.
b) Transient cerebral circulatory disorders (PNMC) are clinically described as acute disorders that are accompanied by focal or cerebral neurological symptoms, which undergo a reverse development during the day. It is important that the neuropsychological examination of the patient makes it possible to detect a functional deficiency even in later periods that are distant from the PIMC, which gives it a decisive role in the diagnosis of this form of cerebral vascular insufficiency. Usually PNMK appear parietal (violation of the praxis of the posture; elements of semantic aphasia; optic-spatial disorders prevailing in the case of right-sided dysgemia localization), temporal disorders (disturbance of the acoustic analysis of rhythms) and posterior perineum (violation of the dynamic praxis, mainly in the case of left-hemispheric dysfunction) symptoms.In some cases, you can see diffuse, fairly erased presented symptoms that do not have a local character.
Thus, a neuropsychological examination allows us to establish the fact of a violation of the cerebral circulation, its topical characteristics and the dynamics of the patient’s condition in PAMA.
c) In ischemic stroke (cerebral infarction), destructive changes in the nervous tissue occur due to impaired cerebral circulation. Subsequent normalization of blood flow does not lead to the restoration of microcirculation in a given area of ​​the brain, or to the opposite development of the destruction of its substance.
As shown by neuropsychological studies outside the acute period of ischemic stroke, the assessment of the form and severity of impaired mental functions requires an approach to analyzing the symptoms not so much due to the localization of the brain infarction, but rather due to the general conditions of cerebral hemodynamics.
In the study of patients in 1-3 days of ischemic stroke, the following data were obtained. Neuropsychological symptoms manifest themselves clearly in dysfunction of both the left and right hemispheres of the brain by pronounced neurodynamic disturbances in the form of the difficulties of including the patient in performing tasks and inertia in changing instructions. At the same time, memory impairments take place, which mainly manifest themselves in the reproduction of semantic passages, combined, as a rule, with a lack of understanding of the figurative meaning of proverbs, the meaning of the plot picture, and the difficulties of solving arithmetic problems. These symptoms indicate a known interest in PMA in general hemodynamic impairment, which is usually not observed in periods distant from stroke.
With left hemispheric strokes, symptoms of complete aphasia and systemic perseveration can be seen.
Right-sided brain damage in this form of vascular disorders is manifested by a more extensive set of symptoms in the form of changes in the emotional sphere (increased mood background, lack of awareness and experience of the disease), impaired orientation in time, impaired body patterns and pronounced syndrome of unilateral spatial agnosia.
d) In cases of thrombosis of the middle cerebral artery (SMA), symptoms of dysfunction of the left hemisphere of the brain of varying degrees of severity and completeness of representation of the symptom complex are especially pronounced. As a rule, at the same time, speech disorders characteristic of all types of aphasia (except dynamic) in their combination come to the fore. A very significant diagnostic sign is the high incidence of sensory aphasia (43% of patients), which is not characteristic of either tumor or traumatic brain damage. However, in its pure form, sensory aphasia is rare in this syndrome, in most cases other aphasic symptoms join it. No less often, thrombosis of the left SMA reveals defects in acoustic and optical-spatial gnosis (in 50% of patients),and also - kinetic and kinesthetic disorders of praxis.
All the symptoms described indicate dysfunction of the temporal (90% of cases), parietal (80% of cases) and posterior perine (50% of cases) areas of the left hemisphere of the brain. In half of the patients, there is a combined failure of all three of these brain structures.
Thrombosis of the right SMA is manifested by a grossly expressed deficiency of optical-spatial functions, acoustic gnosis, various types of praxis and memory.
The severity and structure of neuropsychological syndromes in patients with SMA thrombosis depends on the possibilities of collateral blood supply through the cortical anastomoses from the anterior and posterior cerebral arteries, therefore the state of blood circulation in these vascular basins, as well as the general conditions of hemodynamics, including extracerebral genesis, are essential.
e) Thrombosis of the internal carotid artery (ICA) is characterized by pronounced laterally represented symptoms of impaired mental functions. In cases of thrombosis of the left ICA, speech, optical-spatial gnosis, and various types of praxis are most common. The speech defect, as in the case of CMA thrombosis, is combined, but semantic aphasia (61% of cases) comes to the forefront in terms of frequency of occurrence. Acoustic-mnestic aphasia is found in 50% of observations, but its severity, as a rule, is small, in contrast to the group of patients with SMA thrombosis. Distinctions of opto-spatial gnosis are clearly and significantly expressed in thrombosis of the left ICA, while defects of praxis are represented diffusely and in a rather erased form. Statistical data analysis showsthat in 50% of patients there is a combination of parietal-temporal-foolate symptoms, in 40% of parietal-temporal symptoms and in 10% of patients the symptoms of dysfunction of the parietal brain region are manifested in isolation.
Thrombosis of the right ICA in 100% of cases leads to the formation of opto-spatial disorders, which in the general neuropsychological syndrome are also leading in severity and breadth of their manifestation spectrum in various types of mental activity, primarily visual-constructive. Violations of the visual gnosis are observed with a high frequency (83% of cases), which with a similar constancy are found only in this group of patients. They do not take the form of true subject agnosia, but are clearly represented by the fragmentation of visual perception and paragnosias. A striking feature of patients with thrombosis of the right ICA is the phenomenon of ignoring in various sensory systems (50% of cases). Besides,As specific symptoms for this pathology, a relatively high degree of severity and frequency of tactile gnosis disorders should be noted.
In general, in the group of patients with thrombosis of the right ICA, it can be noted that the most characteristic of it is dysfunction of the parieto-occipital systems (80% of patients), which in half of the cases is combined with insufficiency of the back skin structures and in 30% of cases - with dysfunction of the temporal region of the right hemisphere. the brain. In addition, in 25% of patients, symptoms from the left hemisphere of the brain occur.
Objective clinical research data show that the presence of symptoms of visual gnosis disorders and symptoms of dysfunction of the opposite hemisphere of the brain correlates, respectively, with involvement in the blood supply of the thrombotic VSA of the vertebro-basilar and opposite carotid arteries. These facts allow us to interpret both of the above symptoms as a manifestation of “stealing” of either the Air Force or the carotid system in the opposite hemisphere of the brain.
Comparison of neuropsychological syndromes of thrombosis of MCA and ICA allows us to draw the following conclusions. With a similarity in the breadth of the spectrum of mental function disorders associated with a deficiency of the same brain structures (parietal, temporal, posterior foramen), SMA thrombosis is characterized by much more represented left-hemispheric symptoms, while with ICA thrombosis, there is a complex set of symptoms of right brain hemispheres. In addition, the speech disorders that appear in both groups in the foreground, with the left hemispheric localization of the pathological process, are manifested differently with the CMA and the ICA thrombosis in terms of the incidence of symptoms, respectively, of sensory or semantic aphasia. Thrombosis of SMA is also characterized by the presence of violations of the dynamic praxis (posterior perineum regions of the left hemisphere of the brain),and for thrombosis of the ICA - disorders of the visual gnosis (parietal-occipital regions of the right hemisphere) and symptoms from the opposite hemisphere of the brain.
Comparing the neuropsychological syndromes caused by spasm or thrombosis in identical vascular basins, it should be noted that thrombosis is characterized by a low incidence of mental disorders with a high degree of speech, gnostic and motor disorders. In the case of spasm, the opposite structure of the mental function defect is observed. In a certain sense, in their structure, the syndromes that form as a result of SMA and ICA thrombosis are similar to the local brain pathology of a tumor genesis. But as a distinctive feature due to impaired hemodynamics are a wide range of brain structures involved in the pathological process, an unusually high incidence of sensory and semantic aphasia and a relatively high frequency of disturbances of dynamic praxis.

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