Agnosia - This is a perceptual dysfunction that occurs on the background of the preservation of consciousness and sensitivity. In other words, agnosia is a disorder of different types of perception and appears due to a lesion of the cortex and nearby subcortical areas of the brain. This pathology is characterized by a connection with damage to the secondary (projection-association) areas of the cerebral cortex, which are responsible for the analysis and synthesis of the information obtained. This leads to a disorder in the recognition of stimuli, causing a violation of the recognition of objects and the wrong response to the stimuli obtained.

Symptoms of agnosia

Damage to the cerebral cortex, responsible for the analysis and synthesis of information, generates agnosia. Therefore, the symptoms will depend on the location of the affected area of ​​the brain. For example, due to the defeat of the left zone of the occipital region, subject agnosia is born, which consists in the loss of patient data about the object and its purpose. In other words, an individual suffering from this violation of perception sees the object, can describe it, but is unable to name it and tell about its purpose. When the temporal region is damaged, there is an acoustic-speech perception disorder: the patient perceives the speaker's speech, as if this is a normal set of sounds, he is unable to perceive the meaning of phrases and distinguish individual words. Statistics show that the disorder in question is quite rare.

The causes of agnosia are as follows: dysfunctions of the temporal and parietal areas of the brain, where data on the use of familiar objects are stored (often occurs suddenly after a stroke, heart attack or head injury, when the cortex and nearby subcortical brain formations are affected, and damage to the cortex can cause a tumor process ). In addition, the pathology in question may arise as a result of degeneration of brain areas that are responsible for the integration of perception, memory and identification processes.

Thus, the main causes of agnosia are damage to the parietal and occipital areas of the cerebral cortex, which occur, in addition to the above pathologies, for the following ailments:

- chronic circulatory disorders in the brain, further developing into dementia;

- inflammatory processes of the brain (for example, encephalitis);

- Alzheimer's disease, which is associated with the accumulation of amyloid in the brain (a specific protein that normally normally quickly disintegrates in the brain);

- Parkinson's disease, characterized by the occurrence of progressive muscle stiffness, tremors, and a number of neuropsychological disorders, including apraxia.

Different types of perceptual dysfunction can be distinguished depending on the location in the brain of the affected area. For example, when the parietal-occipital zone is damaged, there is a violation of topographic orientation, with a lesion of the right subdominant portion of the parietal lobe - anosognosia, which is the absence in patients of a critical assessment of their own illness or defect. For example, people suffering from this form of dysfunction, consider themselves completely healthy, even against the background of the immobility of one side of the body (state of paralysis).

Many people, far from medicine, are asking agnosia, what is it, what are the symptoms of this disease, how do they appear?

The following manifestations and symptoms of agnosia can be distinguished:

- violation of spatial orientation and the ability to "read" on the map, that is, to understand the location of cities, districts and other places on the map;

- disorder of the ability to recognize objects by touch (it is difficult for sick people to determine the texture, shape and shape of the object;

- denial of the fact that they have a physical defect or illness (for example, blindness, deafness), despite the indisputability of existing defects;

- indifference to the presence of a defect (a person may be disturbed a little by suddenly frolicking deafness, blindness or other defects;

- impaired sound recognition (the patient is not able to make out the nature of the sound, to understand where it comes from, for example, when he hears a call in his own house or the voice of a relative;

- dysfunction of perception of his own body (people are not able to correctly determine the number of their limbs or their length);

- a disorder of the ability to recognize the faces of acquaintances, along with this, patients are able to give them an approximate age or sex;

- impaired recognition of complex visual images, while patients retain the ability to recognize individual components of these images, for example, an individual, looking at an image, recognizes a jug on the table, but is unable to understand that there is a jug, glasses, plates, and food on the table, it shows that a feast was shown in the picture;

- ignoring part of the visible space (for example, a patient in the process of eating food eats food only from the right side of the plate).

Types of agnosia

The described disorder is characterized by three main varieties: tactile, visual and auditory perception disorders. In addition, it is possible to identify a number of less common forms of the ailment under consideration (for example, spatial agnosia).

Visual agnosia is characterized by the presence of a lesion in the occipital region of the brain. This form of the disease manifests itself in the inability of patients to recognize images and objects while maintaining visual acuity. The type of pathology considered may manifest itself in different ways. The following forms of visual agnosia are distinguished: subject, color, visual, simultaneous agnosia, protopagnosia, and Balint syndrome.

Auditory perceptual dysfunctions occur due to damage to the cortex of the temporal zone of the right hemisphere. This type of agnosia is represented by the inability of individuals to recognize speech and sounds against the background of the normal working capacity of the auditory analyzer. Auditory agnosias, in turn, are subdivided into simple auditory perception disorder, auditory and tonal auditory agnosia.

A simple violation of auditory perception is characterized by the inability of people to recognize simple, previously familiar sounds, such as the sound of rain, the rustle of the sea, knocking, doorbell, squeak, etc.

Oral-verbal agnosia is the impossibility of speech recognition. To a person suffering from the described form of agnosia, native speech seems to be a set of unfamiliar sounds.

The tonal derangement of the auditory perception is characterized by the inability to grasp the emotional coloring, tone, timbre of speech against the background of preserving the ability to perceive words adequately and to correctly distinguish grammatical structures.

Tactile agnosia is the inability to identify objects, things to the touch. The following varieties of the considered species of agnosia are distinguished: somatoagnosia, astereognosia, and impaired spatial perception. The inability of the patient to recognize parts of his own body and assess their location relative to each other is called somatoagnosis. A violation of tactile perception, in which the process of recognizing objects and things through touch is called astereognosia.

There are also violations of spatial perception, expressed in the form of incorrect identification of space parameters. Lesions of the middle sections of the occipital-parietal region are found in the inability to measure values ​​closer or further, and to correctly place objects in three-dimensional space, especially in depth, damage to the left hemisphere entails spatial agnosia, manifested by impaired stereoscopic vision. In addition, there are such types of agnosia as unilateral violation of spatial perception and perceptual disorder, which consists in the inability to topographically navigate the terrain. Unilateral spatial agnosia is the inability to recognize one half of the space. Violation of topographic orientation is expressed in the inability to recognize familiar places against the background of preservation of the memory function.

One of the rarest varieties of agnosia is dysfunction of perception of movement and time. This ailment is manifested in the violation of the correct understanding of the movement of objects and an adequate assessment of the speed of time. The impossibility of perceiving objects in motion is called akinotepsia.

Visual agnosia

Disorder of gnosis or agnosia is a violation of recognition, recognition and understanding of objects, objects and phenomena, originating from the dysfunction of higher cognitive mechanisms that ensure the integration of simple sensations and are responsible for the formation of complete images in the mind. Gnosis is the function of perception, which is carried out arbitrarily.

Disorders of gnosis also include visual perception dysfunction. Visual agnosia, what is it is described in more detail below.

Violation of visual perception is a disorder of the integrity of individual visual sensations, which leads to the impossibility or difficulties in recognizing objects and their images against the background of vision preservation. Gnosis disorder always arises against the background of normal functioning of sensory support (for example, visual acuity and other characteristics remain).

Particularly difficult is the recognition of an object from its contour, fragmentary line image. The visual form of agnosia occurs due to damage to the cortex of the parieto-occipital region of the brain. With this type of illness, the patient is not able to draw a given object, since the holistic perception of the image of this object is disturbed.

Varieties of the considered form of the disease are apperceptive, visual, spatial, associative, subject, color, simultaneous agnosia, as well as violations of the perception of individuals.

Visual agnosia is expressed by the weakness of optical representations due to bilateral damage to the occipital-parietal zone. Individuals suffering from this form of the disease are unable to represent any object and to characterize it (for example, to name its size, shape, color, etc.).

Apperceptive agnosia (the convexital surface of the left part of the neck is affected) is characterized by the impossibility of recognizing holistic objects and their images against the background of the preservation of the perception of certain signs of these objects. In other words, the patient is not able to identify various objects, cannot determine which objects are in front of him, but is able to describe their individual signs.

Associative agnosia is found in the disorder of the ability to recognize and name whole objects and their images against the background of the preservation of their distinct perception.

Balint syndrome is a type of visual impairment caused by optical motor disturbances due to bilateral parietal parietal damage. It manifests itself in the inability to control the view (the patient can not direct it in the right direction). People with this type of agnosia are not able to focus their gaze on a particular object. This is most noticeable when reading. It is difficult for patients to read normally, since it is difficult for them to move from one word to another.

Spatial agnosia is characterized respectively by a violation of spatial orientation or the inability to evaluate three-dimensional relationships.

Color agnosia occurs in the pathology of the occipital region of the left hemisphere. It manifests itself in the inability to systematize colors, recognize identical colors, match a particular shade with a specific object or object.

Simultaneous agnosia occurs due to damage to the anterior part of the occipital lobe. It manifests itself by a sharp decrease in the number of parallelly perceived objects. Often, patients can see only one object.

Prosopagnosia or impaired perception of individuals begins when the lower occipital segment of the right hemisphere is damaged. This form of the pathology is found in the violation of the processes of recognition of faces with the preservation of the ability to recognize objects and objects. In particularly difficult cases, patients are not able to identify their own face in the mirror.

Treatment of agnosia

The pathology in question is an anomalous state in which all perceptual functions are impaired against the background of the integrity of the health of all organs responsible for sensitivity and consciousness. A person with agnosia cannot distinguish one object from another with the help of his own feelings. This disorder is inherent regardless of the age category of people. Most often manifested in the range of ten to 18 years.

The described pathology belongs to the category of rather rare violations. It originates due to a number of factors and is characterized by an individual course. Often, sick people need urgent, specialized care.

Diagnosis of agnosia is directed, in the first turn, at identifying the cause of the disease in question, and determining the affected brain segments, since the type of the disease is directly related to the location of the pathological area. So, for example, simultaneous agnosia, as indicated above, is caused by abnormalities in the occipital region, auditory perception disorder is caused by defects in the temporal segment of the brain, the objective form of the ailment is caused by inferior parietal areas, spatial agnosia is inherent in the parietal-occipital zones.

Diagnosis of agnosia begins with a thorough examination by the therapist and a comprehensive history collection. In the first turn, it is necessary to clarify the presence of chronic illnesses, stroke, neoplastic processes, whether any injuries were previously transferred by a person. If there are any diseases besides agnosia, then it is necessary to find out the time of the first manifestations of the disease, the course of development and the degree of their progression.

In order to establish a definitive direct diagnosis, an interdisciplinary approach is important, which consists in consulting specialists in various fields of medical science, such as psychiatry, otolaryngology, ophthalmology, cardiology, etc.

In addition, to study the functions of the psyche, the health of the visual and auditory analyzers, it is necessary to conduct various tests. If the therapist suspects a violation of spatial perception in a patient, he asks the latter to examine the map and describe the environment. When a tactile perception disorder is suspected, the patient is asked to close his eyes and give him various items that he has to characterize. In the absence of a result, they are asked to repeat the same thing, but already with open eyes. If a patient is supposed to have simultaneous agnosia, then he will be shown images, asked to evaluate a single picture, images and determine their meaning. The tests described above are necessary for the differential diagnosis of the disease under consideration with other pathological conditions.

In addition to the measures described, to establish a direct diagnosis and determine the variation of agnosia, additional examinations are carried out, such as computed tomography and magnetic resonance imaging, with the help of which it becomes possible to identify the damaged areas and brain segments, as well as to determine the expected factors that gave rise to the development of the pathology under consideration.

Specific methods of exposure and specific methods for the treatment of agnosia has not been developed today. It is believed that in the first turn, it is necessary to get rid of the main disease that gave rise to a perception disorder.

After recovery from the main pathology, it is recommended to conduct a series of corrective actions aimed at restoring the patient's condition after a course of treatment of the main disease. For this purpose, doctors recommend the following:

- speech therapy classes (more important in the derangement of the auditory perception);

- psychotherapeutic sessions;

- classes with qualified teachers;

- occupational therapy.

In general, the recovery period for individuals suffering from agnosia takes no more than a three-month course. In case of serious structural brain damage, the duration of the rehabilitation period can be delayed for 10 or more months.

According to the data provided by statistical studies, timely diagnosis of the pathology under consideration, rational therapy and adequate remedial measures lead to the absolute restoration of all analyzers.

The prognosis may be unfavorable for the practice of self-treatment, as well as due to the untimely treatment of specialists and the failure of medical prescriptions. Из-за халатности в отношении собственного здоровья может увеличиться риск возникновения необратимых нарушений в структурах головного мозга.

Indicators of the level of influence of the considered disease on the patient directly depend on its variety. For example, a disorder of spatial perception and a simultaneous form of agnosia give rise to significant impairments of habitual life activity, lifestyle, reduce labor functionality and interfere with normal communicative interaction, while the finger and tonal forms of this disease occur almost unnoticed.

In order to prevent the development of this abnormality, it is important to pay attention to one’s own state of the body, eat well, try to maintain a healthy lifestyle, and if you detect the first signs of illness, seek immediate medical attention, since there are no specific preventive measures.