Apraxia — disorder of ability to perform consecutive operations at preservation of necessary volume of touch and motive functions. Arises at defeat of various departments of bark, subcrustal knots. It is diagnosed according to the neurologic inspection including specific neuropsychological tests. The reason of the revealed violations is defined by means of methods of neurovisualization (MPT, KT, MCKT). Treatment of apraxia depends on a defeat etiology, is performed with application of medicamentous, neurosurgical, rehabilitation techniques.
Praksis — in translation from Greek "action", in medical understanding — the highest nervous function providing ability to make purposeful consecutive actions. Training in skillful implementation of difficult motive acts happens in the childhood with the participation of various zones of bark and subcrustal . In the subsequent often performed daily operations reach the level of avtomatizm, are provided with mainly subcrustal structures. Loss of the acquired movement skills at safety of the motive sphere, a normal muscular tone received the name apraxia. For the first time the term was offered in 1871. The detailed description of violation is made by the German doctor Lipmann who created the first classification of pathology at the beginning of the 20th century.
Violations of a praksis arise at damage of various sites of a brain: bark, subcrustal educations, the nervous ways providing their interaction. Most often apraxia accompanies defeat of frontal and parietal cortical areas. Act as the damaging etiofaktor:
- Brain tumors. The intracerebral new growths (a glioma, an astrotsitoma, a ganglioneyroblastoma) sprouting in bark, the subcrustal centers have the damaging effect on the zones participating in providing a praksis.
- Strokes. The hemorrhagic stroke (hemorrhage in a brain) arises at a gap in a wall of a cerebral vessel, ischemic — at a thrombembolia, a spasm of brain arteries.
- Craniocereberal injuries. Apraxia direct damage responsible for cerebral sites causes, their secondary defeat owing to formation of a post-traumatic hematoma, hypostasis, ischemia, inflammatory reaction.
- Infectious defeats. Encephalitis, meningoentsefalita of various etiology, brain abscesses with localization of the inflammatory centers in bark, subcrustal gangliya.
- Degenerate processes. The diseases which are followed by the progressing cortical atrophy: dementia, disease of Peak, Alzheimer, alcoholic encephalopathy, kortikobazalny degeneration. Are caused by chronic cerebral ischemia, toxic defeat (alcoholism), dismetabolichesky violations (diabetes), genetic factors.
Refer age to the risk factors increasing probability of development of frustration of a praksis 60 years, hereditary predisposition, a hypertension, a stroke in the anamnesis, cardiovascular diseases, chronic alcoholism are more senior.
The mechanism of formation organized in time and space of difficult movements is in a studying stage. It is known that the neurophysiological basis of consecutive actions is provided by wide network of mezhneyronalny contacts of various anatomo-functional zones of both hemispheres. Sodruzhestvenny work of all departments of system is necessary for performance of the fulfilled and new actions long ago. The primary role of a prepotent hemisphere is observed at implementation of difficult organized movements directed to the solution of the new task lying out of habitual behavior. Apraxia arises at malfunction of certain sites of system under the influence of the etiologichesky factors stated above. The complex organization of system of a praksis, entry into it of various cerebral structures provides wide variability of a clinical picture, existence of numerous types of apraxia.
The division of frustration of a praksis according to the level of failure in a chain of formation of consecutive action offered by Lipmann is applied in foreign neurology and now. According to this classification apraxia is divided on:
- Ideomotorny. It is shown by difficulties at implementation of simple motive acts. It is observed at defeat of a parietal share in area of a nadkrayevy and angular crinkle, a premotorny zone, means of communication between them, mezhpolusharny cortical and cortical and subcrustal communications.
- Ideatorny. It is connected with difficulties of consecutive commission of difficult actions at the correct performance of their separate parts. Specific zones of cerebral damage are not defined. Ideatorny apraxia meets at damage of parietal, frontal lobes, subcrustal structures.
- Limbiko-kinetichesky. It is characterized by lack of dexterity and speed of thin movements, it is visible mainly in brush fingers. Arises kontrlateralno to the defeat center. A number of authors connects a limbiko-kinetic form with damage of premotorny bark of a frontal lobe, violation of its communications with basal structures. Other researchers point to lack of accurate differences of the given pathology from easy violations of the motive sphere (pyramidal insufficiency).
Domestic neurologists use classification of the founder of the Soviet neuropsychology A. R. Luriya assuming division of violations of a praksis according to the mechanism of their emergence. Respectively, apraxia shares on:
- Kinetic — disorder of dynamics of the act of the movement, violation of transitions between the separate simple movements forming uniform difficult action. Apraxia has bilateral character, is less expressed on the party of defeat.
- Kinesteticheskaya — violation of thin actions (fastening of buttons, setting of laces) owing to loss of ability to select the necessary movements.
- Spatial — difficulties of performance of the spatial focused actions (clothing, zastilany beds). As separate subspecies constructive apraxia — loss of ability to create whole of separate parts acts.
- Regulatory — difficulties in planning, control, assimilation of performance of new difficult actions.
As the difficult mechanism of a praksis is definitely not installed, some modern writers criticize the specified classifications, suggest to distinguish apraxia forms taking into account concrete functional violations. According to this principle clothing apraxia, walking apraxia, apraxia of manipulations with objects and so forth is allocated.
As uniform clinical symptom disorder of performance of actions at safety of necessary volume of sensomotorny function acts. Patients have no sensitivity violations, paresis, the expressed changes of a muscular tone. Their extremities are capable to carry out the movements at the level of the healthy person. Action is not implemented because of loss of the sequence of movements. Apraxia can proceed against the background of other disorders of higher nervous activity (agnosia, amnesia), decrease in the cognitive sphere.
Kinetic apraxia is characterized by violation of smoothness of transition between consecutive elements of action, "jamming" of the patient on performance of a separate motive element. The rough awkward movements are typical. Frustration concerns both new, and habitual actions. At a kinestetichesky form the patient is incapable to carry out the thin movements by fingers (to clasp/undo buttons, to sew, knot), to give to hands the pose shown by the doctor, in the course of action cannot pick up necessary position of fingers. Lack of visual control aggravates a situation. The patient loses ability to show action without subject (without having a cup, to show the movements necessary for a water nalivaniye in a cup).
Spatial apraxia is shown by disorder of representations "the right / left", "top/bottom", is combined with spatial agnosia. The patient cannot independently put on, collect a subject from parts, at defeat of a prepotent hemisphere writing of letters is at a loss. Regulatory apraxia differs in safety of simple, habitual actions against the background of the broken performance of new. Motive acts are characterized by banality. Implementation of the new action program (a task to kindle a candle by means of a match) is followed by sliding on the simple automated operations (at smokers — attempt to light up a candle it is similar to a cigarette), performance of a separate fragment (ignition and clearing of a match).
Persistent apraxia leads to an invalidization which degree depends on a pathology form. The patient is professionally insolvent, often incapable of self-service. Awareness of own defect causes heavy psychological discomfort, promotes social disadaptation.
Due to the lack of uniform classification, exact understanding of pathogenesis and a morphological substratum detection of apraxia is a difficult task for the neurologist. Diagnostics is performed against the background of an exception of other mechanisms of motive violations, definition of nature of cerebral defeat. Inspection of the patient includes:
- Neurologic survey. It is directed to assessment of the sensitive, motive, cognitive sphere. Helps to find the accompanying focal symptomatology (paresis, disorders of sensitivity, extrapyramidal giperkineza, a cerebellar ataxy, dysfunction of cranial nerves, violations of memory, thinking). Violations of a praksis can be combined with paresis, a gipesteziya. In such cases the diagnosis "apraxia" is established if the existing motive violations do not keep within a framework of the specified frustration.
- Neuropsychological tests. A number of tests in which the patient makes actions according to the instruction is carried out, copies poses and the movements of the doctor, makes whole of parts, makes actions with one/several objects and without them. Separate tests are carried out blindly. The analysis of results includes assessment of quantity and character of errors of implementation of tests.
- Neurovisualization. It is made by means of brain KT, MPT, MCKT. Allows to diagnose the defeat center: tumor, stroke zone, abscess, hematoma, inflammatory focuses, atrophic changes.
It is necessary to differentiate apraxia from extrapyramidal disorders, pyramidal insufficiency, a touch ataxy, cerebellar violations, agnosias. The formulation of the diagnosis has to contain the instruction on the main disease (a trauma, a stroke, encephalitis, Alzheimer's disease, etc.).
Treatment of apraxia
Therapy is carried out concerning a causal disease. According to indications apply pharmacotherapy, neurosurgical treatment, recovery techniques.
Medicamentous therapy includes:
- Improvement of cerebral haemo dynamics. Vascular therapy at sharp and chronic ischemic defeats is made with application vasodilating (), thrombolytic (heparin), the means improving microcirculation (). At a hemorrhagic stroke introduction of medicines of aminocaproic acid, vasoprotectives is made.
- Neurotyre-tread therapy. It is directed to increase in resistance of neurons to a hypoxia, dismetabolichesky shifts at sharp violations of brain blood circulation, injuries, inflammatory processes.
- Nootropic therapy. Nootropa (piracetam, gamma aminooleic acid, a ginkgo of a bilob) increase activity of neurons, improve mezhneyronalny interaction, promotes restoration of cognitive functions.
- Etiotropny treatment of neuroinfections. According to an etiology antibiotic treatment, antiviral, antimikotichesky treatment is carried out.
Neurosurgical interventions are carried out according to indications for the purpose of restoration of intrakranialny blood supply, removal of an intra cranial hematoma, abscess, a tumor. Operations are carried out by neurosurgeons urgently or in a planned order. Rehabilitation therapy is based on the special occupations with the doctor-reabilitologom allowing to improve cognitive abilities to partially compensate frustration of a praksis, to adapt the patient to the arisen neurologic deficiency.
Forecast and prevention
Apraxia has various forecast directly depending on the nature of causal pathology. After a stroke, ChMT, encephalitis extent of restoration depends on weight of defeat, age of the patient, timeliness of rendering the qualified medical care. Inoperable tumoral processes, the progressing degenerate diseases have the adverse forecast. Preventive actions consist in the prevention of injuries of the head, infections, cancerogenic influences; timely treatment of cardiovascular diseases, tserebrovaskulyarny pathology.