Ischemic stroke
The content of the article:
- Causes and risk factors
- Forms of the disease
- Symptoms
- Diagnostics
- Treatment
- Possible complications and consequences
- Forecast
- Prevention
Ischemic stroke is a medical emergency, which is an acute violation of cerebral circulation, which develops due to a decrease or cessation of blood supply to any area of the brain. As a rule, necrosis of the affected area develops against the background of a stroke.
Ischemic stroke is an acute disorder of cerebral circulation
Ischemic stroke is an extremely common pathology, in developed countries in the structure of mortality it is in third place after cardiovascular pathology and malignant neoplasms. In Russia, about 450 thousand cases of stroke are registered annually (more than 3 cases per 1000 population).
The first descriptions of the disease are found in the writings of Hippocrates under the name "apoplexy" (Greek ἀποπληξία - blow), but the involvement in the pathological process of the vessels supplying the brain tissue was confirmed only in the 19th century. A full-fledged classification of acute disorders of cerebral circulation, when ischemic stroke was singled out in a separate category, appeared in 1928.
Ischemic stroke is directly related to a violation of the patency of the vessels supplying the brain tissue, against the background of which an acute shortage of oxygen and glucose occurs in the involved areas, irreversible changes develop (neurons remain viable for 6-8 minutes, provided that the volume of blood flow in the damaged area decreases to 10- 15 ml per 100 g of medulla per minute).
An irreversibly damaged area is called nuclear or medullary ischemia; a therapeutic effect on this area has no prospects. Along the periphery of the central area, there is a structurally unchanged zone of the so-called ischemic penumbra or penumbra (blood flow 20 ml or more per 100 g per minute), where a minimum level of viability is maintained for several hours after a neurological catastrophe.
The penumbra area with a critically low blood supply can be saved with emergency treatment in the first 3–6 hours. Otherwise, the energy and protein metabolism in it stops, and after the functional rearrangement, structural changes develop, necrosis of the brain tissue of the damaged area occurs.
Causes and risk factors
The triggering factor for the development of ischemic stroke is the cessation of blood flow to a certain area of the brain due to impaired patency of the feeding arteries or changes in hemodynamics, which is its fundamental difference from hemorrhagic stroke, when a vessel ruptures with subsequent bleeding.
The most common causes of cerebral ischemia:
- atherosclerotic vascular disease of the brain and spinal cord of medium and large caliber;
- thromboembolism;
- a critical decrease in blood pressure (BP);
- anomaly of the vascular system of the brain;
- septal stenosis of the arteries;
- defeat of small-caliber perforating arteries;
- pronounced changes in the coagulation system.
High cholesterol is one of the risk factors for ischemic stroke
Risk factors for ischemic stroke:
- old age (the risk of the likelihood of ischemic stroke in patients 65–75 years old is on average 6 times higher than in patients 40–50 years old);
- hypercholesterolemia;
- diabetes mellitus (increased risk by a maximum of 4 times);
- transient ischemic attacks (TIA) in the past (almost half of patients who have had TIA within 5 years develop ischemic stroke);
- smoking (increasing the risk by a maximum of 4 times);
- hypovolemia;
- ischemic heart disease (increased risk by a maximum of 4 times);
- sharp bradycardia;
- valvular heart disease;
- atrial fibrillation (increased risk by approximately 5 times);
- septic endocarditis;
- acute massive blood loss;
- coagulopathy;
- vasculitis;
- arterial hypertension (increased risk by approximately 5 times).
Forms of the disease
Depending on the pathogenesis, the following types of ischemic stroke are distinguished:
- atherothrombotic - develops against the background of narrowing of the lumen of blood vessels by atherosclerotic masses;
- cardioembolic - blockage of the arteries by a blood clot formed in the cavities of the heart;
- hemodynamic - depletion of cerebral blood flow due to a critical decrease in blood pressure;
- lacunar - in a limited area supplied with blood by a small perforating artery, due to its damage during sudden changes in blood pressure;
- by the type of microocclusion - increased platelet aggregation in combination with increased blood viscosity.
Depending on the localization of the pathological focus:
- in the carotid basin (internal carotid artery, anterior or middle cerebral arteries);
- in the vertebrobasilar basin (vertebral and basilar arteries, cerebellum, posterior cerebral artery, thalamic structures);
- left-sided;
- right-sided.
By the affected area:
- territorial - develops in the area of blood supply of one of the main large arteries, as a rule, extensive;
- watershed zones - at the junction of the areas of blood supply of several arteries, often of medium size;
- lacunar - in areas supplied with blood by small perforating arteries.
Symptoms
The signs of ischemic stroke can be divided into 2 large groups: cerebral and focal manifestations.
General cerebral symptoms:
- sharp headache, dizziness;
- nausea, vomiting;
- convulsions;
- vegetative disorders (sweating, palpitations, fever, rapid breathing, paresthesia).
Focal symptoms:
- limitation of movement (paralysis, paresis) of the limbs;
- paralysis, paresis of the facial muscles (drooping of the corner of the mouth, eyes, smoothing of the nasolabial fold, "sailing" cheek, asymmetrical smile);
- visual impairment ("flies", luminous stripes, colored spots in front of the eyes, decreased visual acuity, double vision, loss of visual fields, in severe cases - complete blindness);
- violation of the body scheme;
- paresis of the gaze;
- unsteadiness of gait;
- complete or partial loss of speech, dysarthria, impaired reading and writing skills;
- difficulty or inability to perform purposeful actions, complex motor acts;
- disorientation in time and place;
- confusion of consciousness; contact is impossible or difficult;
- delirium, hallucinations;
- behavioral disorders (agitation, unintended excitement or, on the contrary, apathy, indifference);
- memory impairment of various kinds; etc.
One of the symptoms of ischemic stroke is paresis and paralysis of the facial muscles
The set of focal symptoms is characteristic for the specific localization of the ischemic zone, the extent of the lesion, and the presence of accompanying aggravating factors.
Diagnostics
Diagnosis of ischemic stroke is based on a comprehensive assessment of the data of objective and instrumental research methods:
- neurological examination;
- Ultrasound examination of the arteries of the head and neck;
- computed and magnetic resonance imaging;
- angiography;
- transcranial Doppler ultrasound;
- electroencephalographic study.
Ischemic stroke on CT
Treatment
Treatment of ischemic stroke is carried out in several directions:
- restoration of blood supply to areas of hypoperfusion (maintenance of systemic hemodynamics, drug thrombolysis, anticoagulant and antiplatelet therapy, surgical methods of recirculation: imposition of microanastomoses, thrombectomy, reconstructive surgery on the arteries);
- neuroprotection of brain tissue from the damaging effects of toxic metabolites;
- normalization of the function of external respiration (sanitation of the bronchial tree, installation of an air duct, hyperbaric oxygenation, if necessary - mechanical ventilation);
- normalization of the cardiovascular system;
- control and regulation of homeostasis (glucose level, water-salt balance);
- reduction of cerebral edema;
- symptomatic therapy (anticonvulsants, antiemetics, sedatives, tranquilizers, antipsychotics).
Possible complications and consequences
Complications of ischemic stroke can be:
- hypostatic pneumonia;
- respiratory distress syndrome;
- bedsores;
- accession of a secondary infection, sepsis;
- phlebothrombosis of the lower extremities;
- hypoxic stomach ulcer;
- secondary hemorrhage;
- edema of the brain with impaired respiratory and cardiac activity;
- pulmonary embolism;
- epistatus;
- hypertensive-CSF syndrome;
- pulmonary edema;
- coma, death.
Forecast
The death rate from ischemic stroke is 1.23 cases per 1000 people per year. In the first month, about 25% of patients die. It was noted that the more pronounced the neurological deficit at the end of the first month of the disease, the less chances of restoring the quality of life. Within 5 years, recurrence of ischemic stroke is observed in one third of patients.
Approximately 30% of patients who have suffered a neurological disaster require assistance, and 20% are unable to move independently. No more than 1/5 of patients return to full-fledged work and social activity.
Prevention
- Lifestyle modification, giving up bad habits.
- Decrease in excess body weight.
- Chronic disease control.
- Adequate physical activity.
- Timely therapy of hypertension.
- Antiplatelet therapy.
- Regular intake of lipid-lowering drugs (statins).
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Olesya Smolnyakova Therapy, clinical pharmacology and pharmacotherapy About the author
Education: higher, 2004 (GOU VPO "Kursk State Medical University"), specialty "General Medicine", qualification "Doctor". 2008-2012 - Postgraduate student of the Department of Clinical Pharmacology, KSMU, Candidate of Medical Sciences (2013, specialty "Pharmacology, Clinical Pharmacology"). 2014-2015 - professional retraining, specialty "Management in education", FSBEI HPE "KSU".
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
