Ischemic stroke — the pathological state representing not a separate or independent disease, and the episode developing within the progressing general or local vascular defeat at various diseases of cardiovascular system. Often the ischemic stroke accompanies the following diseases: arterial hypertension, atherosclerosis, rheumatic heart disease, coronary heart disease, diabetes and other forms of pathology with defeat of vessels. The clinic of an ischemic stroke consists of the all-brain and focal symptoms depending on localization of vascular disorders. The most important method of tool diagnosis of an ischemic stroke, and also its differentiation from a hemorrhagic stroke, is KT and MPT of a brain.
Ischemic stroke call the brain violations of blood circulation which are characterized by sudden emergence focal neurologic or the all-brain symptomatology remaining more than 24 hours or the defiant death of the patient in shorter time.
Classification of ishemicheskoy strokes
The ischemic stroke can be a consequence of this or that disease of cardiovascular system. Allocate several pathogenetic options of an ischemic stroke. In classification of TOAST (Trial of Org 10172 in Acute Stroke Treatment) which gained the greatest distribution allocate the following options of an ischemic stroke:
- kardioembolicheskiya — the ischemic stroke which was the result of arrhythmia, valvate heart disease, a myocardial infarction;
- aterotromboticheskiya — the ischemic stroke which was the result of atherosclerosis of large arteries which result was an arterio-arterial embolism;
- lacunary — the ischemic stroke which was the result of occlusion of arteries of small caliber;
- the ischemic stroke connected with other, more rare reasons: blood hyper coagulation, stratification of a wall of arteries, not atherosclerotic vaskulopatiya;
- ischemic stroke of an unknown origin — a stroke with the unspecified reason or with existence of two and more possible reasons when it is not possible to establish the exact diagnosis.
Besides, allocate a small stroke when the available symptomatology regresses within the first three weeks of a disease.
Allocate also several periods of an ischemic stroke:
- the sharpest period — the first 3 days. From them the first three hours received definition of "a therapeutic window" when there is a possibility of use of thrombolytic medicines for system introduction. In case of regress of symptoms within the first days diagnose the tranzitorny ischemic attack;
- the sharp period — up to 4 weeks;
- the early recovery period — before half a year;
- the late recovery period — up to 2 years;
- the period of the residual phenomena — after 2 years.
Etiology and pathogenesis of an ischemic stroke
As the ischemic stroke is not considered as a separate disease, definition of a uniform etiologichesky factor for it is impossible. However there are risk factors associated with the increased frequency of development of an ischemic stroke which can be divided into two groups: modified and not modified. The myocardial infarction, arterial hypertension, vibrating arrhythmia, diabetes, a dislipoproteinemiya, asymptomatic damage of carotids concerns to the first. To the second — hereditary predisposition, age. Besides, there are also risk factors connected with a way of life: low level of physical activity, acute stress or long psychoemotional pressure, excess body weight, tobacco smoking.
The certain sequence of molecular and biochemical changes in brain substance caused by sharp focal ischemia of a brain is capable to lead to fabric violations from which death of cages (a brain heart attack) results. The nature of changes depends on the level of decrease in a brain blood-groove, duration of such decrease and sensitivity of substance of a brain to ischemia. Degree of reversibility of fabric changes at each stage of pathological process is defined by the level of decrease in a brain blood-groove and it lasting a combination to the factors defining sensitivity of a brain to hypoxemic damage.
The term "heart attack kernel" designate a zone of irreversible damage, the term "ischemic penumbra" (penumbr) — a zone of ischemic defeat of reversible character. Duration of existence of a penumbra — the major moment as over time reversible changes accept irreversible character. An oligemiya zone — a zone in which the balance between the fabric requirements and processes providing these requirements despite of decrease in a brain blood-groove remains. It is capable to exist vaguely long time, without passing into a heart attack kernel therefore to a penumbra it is not carried.
Clinical picture of an ischemic stroke
The clinical simptomokompleks at an ischemic stroke is various and depends on localization and the volume of the center of damage of a brain. More others localization of the center of defeat in the carotid pool is widespread (to 85%), is more rare — in vertebralno-bazilyarny.
Feature of a heart attack in the pool of blood supply of an average brain artery is existence of the expressed system of collateral blood supply. Occlusion of proximal department of an average brain artery can cause a subkortikalny heart attack, at the same time the cortical area of blood supply remains not struck. In lack of data kollateraly development of an extensive heart attack in the field of blood supply of an average brain artery is possible.
Emergence of deviation of eyeballs and the head towards the struck hemisphere is typical for a heart attack in the field of blood supply of superficial branches of an average brain artery. At the same time in case of defeat of a prepotent hemisphere ipsilateralny ideomotorny apraxia and total aphasia, and in case of defeat of a subdominant hemisphere — an anozognoziya, a dizartriya, an aprosodiya and contralateral ignoring of space develops.
The main clinical display of a heart attack of a brain in the field of branches of an average brain artery — a contralateral hemiparesis and a contralateral gemianesteziya. In case of the extensive centers of defeat emergence of sodruzhestvenny assignment of eyeballs and fixing of a look towards the struck hemisphere is possible. At heart attacks of a subdominant hemisphere emotional violations and spatial ignoring develop.
Spread of paresis at a heart attack in the pool of blood supply of striatokapsulyarny arteries depends on localization and the amount of defeat (the top extremity, the person or all contralateral part of a body). In case of an extensive striatokapsulyarny heart attack typical manifestations of occlusion of an average brain artery (aphasia, a gomonimny lateral gemianopsiya), as a rule, develop.
The lacunary heart attack is clinically shown by development of lacunary syndromes (the isolated hemiparesis and a gemigipesteziya or their combination).
The most frequent clinical display of a heart attack in the pool of blood supply of a forward brain artery are motive violations. In most cases occlusions of kortikalny branches motor deficiency in foot and all lower extremity, and also poorly expressed paresis of the top extremity with extensive defeat of language and the person develops.
As a result of occlusion of a back brain artery heart attacks of an occipital temporal share, and also mediobazalny departments of a temporal share develop. In such cases defects of fields of vision (a contralateral gomonimny gemianopsiya) act as clinical manifestations. Possibly also their combination to visual hallucinations and fotopsiya.
Heart attacks in the vertebrobazilyarny pool of blood supply result from occlusion of the only punching branch of a bazilyarny artery and are followed, as a rule, by symptoms of defeat of ChN on the ipsilateralny party. Occlusion of a vertebral artery or its main penetrating branches departing from disteel departments leads to development of a syndrome of Wallenberg (a lateral medullary syndrome).
Diagnosis of an ischemic stroke
When collecting the anamnesis it is necessary to decide on the beginning of violations of brain blood circulation, to establish the sequence and speed of progressing of these or those symptoms. For an ischemic stroke typically sudden emergence of neurologic symptoms. Besides it is necessary to pay attention to possible risk factors of developing of an ischemic stroke (diabetes, arterial hypertension, vibrating arrhythmia, atherosclerosis, a hypercholesterolemia, etc.)
Fizikalny examination of the patient with the possible diagnosis "an ischemic stroke" is conducted according to the standard rules on systems of bodies. Estimating the neurologic status, pay attention to existence and expressiveness of all-brain symptomatology ( pain, violation of level of consciousness, generalizirovanny spasms, etc.), focal neurologic symptomatology and meningealny symptoms. Laboratory researches have to include the general and biochemical blood tests, a koagulogramma, the general analysis of urine.
Basis of tool diagnosis of an ischemic stroke — neurovisualization methods. Besides, MPT and KT of a brain use as well for differentiation of an ischemic stroke from other forms of intra cranial pathology and dynamic control over fabric changes during treatment of an ischemic stroke. One of early KT-signs of ischemic damage to system of an average brain artery — lack of visualization of a chechevitseobrazny kernel or bark of an island (owing to the damage of cytotoxic hypostasis developing in a zone).
In certain cases at an ischemic stroke as early changes the giperdensivnost of sites of average and, much more rare, a back brain artery on the party of defeat (a symptom of thrombosis or embolism of these vessels) is defined. At the end of the first week of a disease in a zone of ischemic defeat in gray substance increase in density to izodensivny and even slabogiperdensivny state is observed that demonstrates development of a neovazogenez and restoration of a blood-groove. Such phenomenon has "effect of a zatumanivaniye" as there are difficulties at identification of borders of a zone of ischemic defeat in the subsharp period of a heart attack of a brain.
It is proved efficiency of the new mode of the MRT-research by means of which receive the diffusive weighed images. As a result of cytotoxic hypostasis at an ischemic stroke of a molecule of water pass from extracellular space intracellular, it leads to reduction in the rate of their diffusion. These changes are shown on the diffusion weighed MRT-images in the form of increase in a signal that confirms development irreversible structural damages of substance of a brain.
First of all, the ischemic stroke needs to be differentiated from a hemorrhagic stroke. The crucial role in this question will be played by neurovisualization methods of a research. Besides, in certain cases there is a need of differentiation of an ischemic stroke from sharp hypertensive encephalopathy, metabolic or toxic encephalopathy, a brain tumor, and also infectious damages of a brain (abscess, encephalitis).
Treatment of an ischemic stroke
At suspicion of an ischemic stroke of the patient it is necessary to hospitalize in specialized offices. In case the prescription of a disease makes less than 6 hours — in the block of intensive therapy of the same offices. Transportation has to be carried out only at the position of the head of the patient raised to 30 degrees. Relative restrictions to hospitalization consider a terminal coma, a terminal stage of oncological diseases, and also existence in the anamnesis of dementia with the expressed invalidization.
Non-drug treatment of an ischemic stroke has to include actions for care of the patient, swallowing function correction, prevention and therapy of infectious complications (pneumonia, infections of urinary tract, etc.). Drug treatment of an ischemic stroke is most effective at the very beginning of a disease (3-6 hours after manifestation of the first symptoms of a disease). Coordinate multidisciplinary approach to it should be applied in the conditions of specialized vascular office, the intensive therapy having the block (chamber) about a possibility of the round-the-clock implementation of the ECG, KT, clinical and biochemical blood tests, and also ultrasonographies. At a trombotichesky etiology of a stroke it is carried out selective or system , at kardioembolichesky genesis - antikoagulyantny therapy.
Important component of therapy of an ischemic stroke — correction of the vital functions and maintenance of a homeostasis. Continuous monitoring of the main physiological indicators, correction and maintenance of indicators of haemo dynamics, water and electrolytic balance, breath, correction of the increased intra cranial pressure and hypostasis of a brain, prevention and fight against complications is for this purpose necessary. Routine use of glyukozosoderzhashchiya of solutions is inexpedient because of risk of development of a hyperglycemia, a poet the main infusion solution at treatment of an ischemic stroke is sodium chloride solution (0,9%). At the accompanying diabetes of patients transfer to subcutaneous injections of insulin of short action unless adequate control of a glycemia is carried out, and the patient at the same time is in clear consciousness and without swallowing malfunction.
In the first 48 hours of a disease it is necessary to determine periodically hemoglobin saturation by oxygen of arterial blood. In case this indicator reaches 92%, it is necessary to carry out oxygenotherapy, since 2-4 liters a minute. Decrease in level of consciousness of the patient to 8 points and less (a scale of a coma of Glasgow) — an absolute measure to a trachea incubation. The solution of a question in favor of IVL or against it is accepted, proceeding from the basic general resuscitation provisions. At the reduced wakefulness level, in the presence of clinical or neurovisualization symptoms of hypostasis of a brain or the increased intra cranial pressure maintenance of the head of the patient in the state raised by 30 degrees is necessary (without bending of a neck!). It is necessary to minimize (and whenever possible to exclude) cough, epileptic seizures and motive excitement. Infusions of gipoosmolyalny solutions are contraindicated!
In independence of location of the patient (the block of intensive therapy, resuscitation or neurologic office) a daily problem of basic therapy of an ischemic stroke is adequate food of the patient, and also control and completion water losses. An indicator to carrying out enteralny probe food progressing of these or those disorders of swallowing is considered. At the same time calculation of doses of nutrients should be carried out taking into account metabolic requirements and physiological losses of an organism. At introduction of food orally or via the probe the patient has to be in situation semi-sitting within 30 minutes after feeding.
For prevention of thrombosis of deep veins at an ischemic stroke wearing compression stockings or the corresponding bandaging is shown. In those purposes, and also apply direct anticoagulants (low-molecular heparins) to prevention of a thrombembolia of a pulmonary artery.
The neuropatronage can become one of the most priority directions of therapy of an ischemic stroke. Its main direction — use of medicines with neuromodulator and neurotrophic actions. Medicine of a neurotrophic row most known now is a hydrolyzate from a brain of pigs. A head and spinal cord have no the depositing property, and the termination of a blood-groove for 5-8 minutes causes death of neurons. Therefore introduction of neurotyre-tread medicines needs to be carried out the first minutes of an ischemic stroke. Thus, early rehabilitation against the background of basic therapy, and also the combination of a reperfuziya and a neuropatronage allow to achieve certain success in drug treatment of an ischemic stroke.
Surgical treatment of an ischemic stroke means a surgical decompression — reduction intra cranial pressure, increase in perfuzionny pressure, and also preservation of a cerebral blood-groove. The statistics indicates decrease in level of a lethality at an ischemic stroke from 80 to 30%. In the rehabilitation period after the had ischemic stroke all efforts of neurologists are bent on restoration of the lost motive and speech functions of the patient. The elektromiostimulyation and massage of paretichny extremities, LFK, mechanotherapy is carried out. Consultation of the logopedist is necessary for correction of violations of the speech.
The forecast at an ischemic stroke
The forecast at an ischemic stroke depends, first of all, on localization and the volume of damage of a brain, age of the patient, and also weight of associated diseases. The most serious condition of the patient falls on the first 3-5 days of a disease when brain hypostasis in the field of the defeat center accrues. Further there comes the period of stabilization or improvement with possible restoration of the broken functions. Now the percent of lethal outcomes at an ischemic stroke makes 15-20%.
Prevention of an ischemic stroke
Basis of prevention of an ischemic stroke is prevention of thrombosis of blood vessels which arises when forming in blood of "cholesteric plaques". For this purpose maintenance of a healthy lifestyle, adequate body weight, abstention from smoking and other addictions is necessary. In risk group also the patients having various diseases of cardiovascular system, arterial hypertension, a hypercholesterolemia and diabetes.
Secondary prevention of an ischemic stroke — the comprehensive program including four directions: hypotensive therapy (inhibitors angiotensin - the turning enzyme and diuretics); antitrombotichesky therapy (indirect anticoagulants and antiagregant); gipolipidemichesky therapy (statins); surgical treatment of carotid arteries (carotid endaterektomiya).