Agnosia is a violation of recognition of visual, acoustical or tactile feelings at normal functioning of the perceiving device. According to localization of defeat of cerebral bark the state is characterized by misunderstanding of what was seen heard not recognition of objects at palpation, disorder of perception of own body. It is diagnosed according to a research of the psychoneurological status, to results of neurovisualization (KT. MRT, brain MSKT). Treatment is performed by etiotropny, vascular, neurometabolic, holinesterazny pharmaceuticals in combination with psychotherapy, logopedic occupations.
Gnozis in translation from Greek means "knowledge". Is the highest nervous function providing recognition of objects, phenomena, own body. Agnosia — the complex concept including all violations of Gnostic function. Frustration of a gnozis often accompany degenerate processes of TsNS, are observed at many organic damages of a brain arising owing to injuries, strokes, infectious and tumoral diseases. Classical agnosia is seldom diagnosed for children of younger age as higher nervous activity at them is in a development stage, the differentiation of the cortical centers is not complete. Violations of a gnozis arise at children more often 7 years and at adults are more senior. Women and men get sick equally often.
Gnostic violations are caused by pathological changes of secondary projective and associative fields of brain bark. Defeats of the specified zones act as Etiofaktorami:
- Sharp violations of brain blood circulation. Agnosia results from death of neurons of secondary fields in the field of an ischemic or hemorrhagic stroke.
- Chronic ischemia of a brain. The progressing insufficiency of cerebral blood circulation leads to dementia including Gnostic frustration.
- Brain tumors. Defeat of secondary cortical fields is a consequence of the growth of a tumor leading to a sdavleniye and destruction of surrounding neurons.
- Craniocereberal trauma. Agnosia meets mainly at a brain bruise. Develops owing to damage of secondary zones of bark at the time of a trauma and as a result of post-traumatic processes (formation of hematomas, inflammatory changes, microcirculator violations).
- Encephalitis. Can have a virus, bacterial, parasitic, vaccine-challenged etiology. Is followed by diffusion inflammatory processes in cerebral structures.
- Degenerate diseases of TsNS: Alzheimer's disease, leykoentsefalit Shilder, the Peak disease, Parkinson's disease.
Cerebral bark has three main groups of the associative fields providing the raznourovnevy analysis of information coming to a brain. Primary fields are connected with peripheral receptors, accept the afferent impulsation going from them. Secondary associative zones of bark are responsible for the analysis and synthesis of information arriving from primary fields. Further information is transferred to tertiary fields where the highest synthesis and development of problems of behavior is carried out. Dysfunction of secondary fields leads to violation of the specified chain that is clinically shown by loss of ability to learn external irritants, to perceive complete images. At the same time function of analyzers (acoustical, visual etc.) is not broken.
Depending on area of defeat in clinical neurology agnosia is classified on the following main groups:
- Visual — lack of recognition of objects, images at preservation of visual function. Develops at pathology of occipital, zadnetemenny departments of bark.
- Acoustical — loss of ability to distinguish sounds and phonemes, to perceive the speech. Arises at defeat of bark of the top temporal crinkle.
- Sensitive — violation of perception of own body and recognition of tactile feelings. It is caused by dysfunction of secondary fields of parietal departments.
- Olfactory — disorder of recognition of smells. It is observed at defeat of mediobazalny areas of a temporal share.
- Flavoring — impossibility to identify flavoring feelings at safety of ability to perceive them. Olfactory agnosia is connected with pathology of the same areas, as.
There is also a violation of all forms of a gnozis. This pathology is designated by the term "total agnosia".
Basic symptom of a state — impossibility to learn the perceived feelings at preservation of ability to feel them. In other words, the patient does not understand that he sees, hears, feels. The differentiated agnosia caused by loss of function of the separate struck department of bark is often noted. Agnosia of total character accompanies the pathological processes diffuzno extending in cerebral fabrics.
Visual agnosia is shown by confusion of objects, inability to call the considered subject, to copy it, to draw on memory or the begun drawing. Representing a subject, the patient draws only his parts. The visual form has many options: color, selective agnosia of persons (prozopagnoziya), apperceptive — recognition of signs of a subject (a form, color, the size), associative is kept — the patient is capable to describe a subject entirely, but cannot call it, simultantny — inability to learn a plot from several objects at preservation of recognition of each subject separately, visual and spatial — violation of a gnozis of a relative positioning of objects. Disorder of recognition of letters and symbols leads to a dyslexia, a dysgraphia, loss of ability to do arithmetic calculations.
Acoustical agnosia at defeat of a prepotent hemisphere leads to partial or full misunderstanding of the speech (touch aphasia). The patient perceives phonemes as nothing the meaning noise. The state is followed by compensatory loquacity with repetitions, insertion of casual sounds, syllables. By the letter admissions, shifts can be noted. Reading is kept. Defeat of a subdominant hemisphere can lead to loss of ear for music, ability to learn sounds familiar earlier (rain noise, dog bark), to understand intonational features of the speech.
Sensitive agnosia is characterized by frustration of a gnozis of the irritations perceived by pain, temperature, tactile, propriotseptivny receptors. Includes — impossibility to identify a subject to the touch, spatial agnosia — violation of orientation in the familiar area, hospital chamber, own apartment, a somatognoziya — frustration of feeling of own body (proportionality, the size, existence of its separate parts). Act as common forms of a somatognoziya manual agnosia — the patient is incapable to call fingers, to show the finger specified by the doctor, an autotopagnoziya — feeling of lack of a separate part of a body, a gemisomatoagnoziya — feeling only half of the organism, an anozognoziya — neoconsciousness of existence of a disease or a separate symptom (paresis, relative deafness, deterioration in sight).
Inspection is directed to detection of agnosia, search of its reason. Definition of a clinical form of agnosia allows to establish localization of pathological process in a brain. The main diagnostic techniques are:
- Poll of the patient and his relatives. Aims at establishment of complaints, the beginnings of a disease, its communication with a trauma, an infection, violations of cerebral haemo dynamics.
- Neurologic survey. During the research of the neurologic and mental status along with agnosia the neurologist reveals symptoms of intrakranialny hypertensia, focal neurologic deficiency (paresis, disorders of sensitivity, violation from craniocereberal nerves, pathological reflexes, changes of the cognitive sphere), characteristic of the main disease.
- Consultation of the psychiatrist. It is necessary for an exception of mental disorders. Includes patopsikhologichesky inspection, a research of structure of the personality.
- Tomographic researches. KT, MSKT, MRT of a brain allow to visualize degenerate processes, tumors, the inflammatory centers, zones of a stroke, traumatic damage.
Agnosia is only a syndrome, the sindromalny diagnosis can take place at the initial stage of diagnostics. Establishment of the full diagnosis of a basic disease which clinical picture includes frustration of a gnozis has to be result of above-mentioned researches.
Treatment of agnosia
Therapy depends on the main disease, can consist of conservative, neurosurgical, rehabilitation methods.
- Vascular and thrombolytic pharmaceuticals. Are necessary for normalization of a cerebral blood-groove. Sharp and chronic ischemia of a brain is the indication to purpose of the means expanding cerebral vessels (a vinpotsetin, cinnarizine), antiagregant (pentoksifillin). At intrakranialny hemorrhage apply anti-fibrinolytic medicines, at thrombosis — trombolitik.
- Neurometabolites and antioxidants: glycine, gamma aminooleic acid, piracetam, , oxymethylethylpyridine. Improve exchange processes in cerebral fabrics, increase their resistance to a hypoxia.
- Antikholinesterazny means: , donepezit, . Normalize neuropsychological, cognitive functions.
- Etiotropny therapy of encephalitis. According to an etiology it is carried out by antibacterial, antiviral, antiparasitic medicines.
Rehabilitation of patients lasts not less than three months, includes:
- Psychotherapy. Art therapy, cognitive and behavioural therapy are directed to restoration of the mental sphere of the patient, adaptation to the situation which developed in connection with a disease.
- Occupations with the logopedist. Are necessary for patients with acoustical agnosia, a dyslexia, a dysgraphia.
- Work therapy. Helps patients to overcome feeling of inferiority, to distract with experiences, to improve social adaptation.
Neurosurgical treatment can be required in case of a craniocereberal trauma, a cerebral tumor. It is carried out against the background of conservative therapy with the subsequent rehabilitation.
Forecast and prevention
Success of treatment depends on weight of a basic disease, age of the patient, timeliness of the carried-out therapy. The agnosia arising at young patients owing to a trauma of encephalitis regresses against the background of treatment within 3 months, in hard cases process of restoration takes up to 10 months. Agnosia of tumoral genesis depends on success of removal of education. At degenerate processes the forecast adverse, treatment allows to suspend progressing of symptomatology only. Prevention consists in timely therapy of vascular pathology, the prevention of injuries of the head, onkogenny influences, infectious diseases.