Cerebral infarction
Encyclopedia
A cerebral infarction is the ischemic
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...

 kind of stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

  due to a disturbance in the blood vessels supplying blood to the brain. It can be atherothrombotic or embolic. Stroke caused by cerebral infarction should be distinguished from two other kinds of stroke: cerebral hemorrhage and subarachnoid hemorrhage
Subarachnoid hemorrhage
A subarachnoid hemorrhage , or subarachnoid haemorrhage in British English, is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain...

. A cerebral infarction occurs when a blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...

 that supplies a part of the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

 becomes blocked or leakage occurs outside the vessel walls. This loss of blood supply results in the death of that area of tissue. Cerebral infarctions vary in their severity with one third of the cases resulting in death.

Classification

There are various classification systems for a cerebral infarction.
  • The Oxford Community Stroke Project classification (OCSP, also known as the Bamford or Oxford classification) relies primarily on the initial symptoms. Based on the extent of the symptoms, the stroke episode is classified as total anterior circulation infarct
    Total anterior circulation infarct
    A Total Anterior Circulation Infarct is a type of cerebral infarction affecting the entire anterior circulation supplying one side of the brain....

     (TACI), partial anterior circulation infarct
    Partial anterior circulation infarct
    Partial Anterior Circulation Infarct is a type of cerebral infarction affecting part of the anterior circulation supplying one side of the brain....

     (PACI), lacunar infarct (LACI) or posterior circulation infarct
    Posterior circulation infarct
    A Posterior Circulation Infarct is a type of cerebral infarction affecting the posterior circulation supplying one side of the brain....

     (POCI). These four entities predict the extent of the stroke, the area of the brain affected, the underlying cause, and the prognosis.

  • The TOAST (Trial of Org 10172
    Danaparoid
    Danaparoid sodium is an anticoagulant that works by inhibiting activated factor X .Danaparoid is considered a "low molecular weight heparin" by some sources, but is chemically distinct from heparin and thus has little cross-reactivity in heparin-intolerant patients.It consists of a mixture of...

     in Acute Stroke Treatment) classification is based on clinical symptoms as well as results of further investigations; on this basis, a stroke is classified as being due to (1) thrombosis or embolism due to atherosclerosis
    Atherosclerosis
    Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...

     of a large artery, (2) embolism of cardiac
    Heart
    The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

     origin, (3) occlusion of a small blood vessel, (4) other determined cause, (5) undetermined cause (two possible causes, no cause identified, or incomplete investigation).

Symptoms

Symptoms of cerebral infarction are determined by topographical localisation of cerebral lesion. If the infarct is located in primary motor cortex- contralateral hemiparesis is said to occur. With brainstem localization, brainstem syndromes are typical: Wallenberg's syndrome
Lateral medullary syndrome
Lateral medullary syndrome is a disease in which the patient has a constellation of neurologic symptoms due to injury to the lateral part of the medulla in the brain, resulting in tissue ischemia and necrosis.-Signs and symptoms:This syndrome is characterized by sensory deficits affecting...

, Weber's syndrome
Weber's syndrome
Weber's syndrome is a form of stroke characterized by the presence of an oculomotor nerve palsy and contralateral hemiparesis or hemiplegia.-Cause and presentation:...

, Millard-Gubler syndrome
Millard-Gubler syndrome
-Presentation:Symptoms result from the functional loss of several anatomical structures of the pons, including the sixth and seventh cranial nerves and fibers of the corticospinal tract...

, Benedikt syndrome or others.
Infarctions will result in weakness and loss of sensation on the opposite side of the body
Body
With regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death...

. Physical examination of the head
Head
In anatomy, the head of an animal is the rostral part that usually comprises the brain, eyes, ears, nose and mouth . Some very simple animals may not have a head, but many bilaterally symmetric forms do....

 area will reveal abnormal pupil dilation, light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...

 reaction
Reaction
Reaction may refer to:Response to another event*Adverse drug reaction*Chemical reaction*Emotional reaction*Light reaction*Nuclear reaction*TNA Reaction, a documentary show of TNA behind scenes.*Reaction , as defined by Newton's third law...

 and lack of eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...

 movement on opposite side. If the infarction occurs on the left side brain, speech will be slurred. Reflexes may be aggravated as well.

Causes

In thrombotic cerebral infarction a thrombus usually forms around atherosclerotic
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...

 plaques.
An embolic stroke refers to the blockage of an artery by an embolus
Embolism
In medicine, an embolism is the event of lodging of an embolus into a narrow capillary vessel of an arterial bed which causes a blockage in a distant part of the body.Embolization is...

, a traveling particle or debris in the arterial bloodstream originating elsewhere. An embolus is most frequently a thrombus, but it can also be a number of other substances including fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...

 (e.g. from bone marrow
Bone marrow
Bone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...

 in a broken bone
Bone fracture
A bone fracture is a medical condition in which there is a break in the continuity of the bone...

), air, cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

 cells or clumps of bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 (usually from infectious endocarditis
Endocarditis
Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...

). The embolus may be of cardiac origin or from atherosclerotic
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...

 plaque of another (or the same) large artery.

Risk factors

Risk factors for cerebral infarction are generally the same as for atherosclerosis
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...

: diabetes
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...

, tobacco smoking
Tobacco smoking
Tobacco smoking is the practice where tobacco is burned and the resulting smoke is inhaled. The practice may have begun as early as 5000–3000 BCE. Tobacco was introduced to Eurasia in the late 16th century where it followed common trade routes...

, hypercholesterolemia
Hypercholesterolemia
Hypercholesterolemia is the presence of high levels of cholesterol in the blood. It is not a disease but a metabolic derangement that can be caused by many diseases, notably cardiovascular disease...

, hyperlipoproteinemia, high blood pressure
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...

, obesity
Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...

.

Diagnosis

Computed tomography
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...

 (CT) and MRI scanning will show damaged area in the brain, showing that the symptoms were not caused by a tumor
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

, subdural hematoma
Subdural hematoma
A subdural hematoma or subdural haematoma , also known as a subdural haemorrhage , is a type of haematoma, a form of traumatic brain injury. Blood gathers within the outermost meningeal layer, between the dura mater, which adheres to the skull, and the arachnoid mater, which envelops the brain...

 or other brain disorder. The blockage will also appear on the angiogram
Angiogram
Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins and the heart chambers...

.

Treatment

In last decade, similar to myocardial infarction treatment, thrombolytic drugs were introduced in the therapy of cerebral infarction. The use of intravenous rtPA
Tissue plasminogen activator
Tissue plasminogen activator is a protein involved in the breakdown of blood clots. It is a serine protease found on endothelial cells, the cells that line the blood vessels. As an enzyme, it catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown...

 therapy can be advocated in patients who arrive to stroke unit and can be fully evaluated within 3 h of the onset.

If cerebral infarction is caused by a thrombus
Thrombus
A thrombus , or blood clot, is the final product of the blood coagulation step in hemostasis. It is achieved via the aggregation of platelets that form a platelet plug, and the activation of the humoral coagulation system...

  occluding blood flow to an artery supplying the brain, definitive therapy is aimed at removing the blockage by breaking the clot down (thrombolysis
Thrombolysis
Thrombolysis is the breakdown of blood clots by pharmacological means. It is colloquially referred to as clot busting for this reason...

), or by removing it mechanically (thrombectomy). The more rapidly blood flow is restored to the brain, the fewer brain cells die. In increasing numbers of primary stroke centers, pharmacologic thrombolysis with the drug tissue plasminogen activator
Tissue plasminogen activator
Tissue plasminogen activator is a protein involved in the breakdown of blood clots. It is a serine protease found on endothelial cells, the cells that line the blood vessels. As an enzyme, it catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown...

 (tPA), is used to dissolve the clot and unblock the artery.
Another intervention for acute cerebral ischaemia is removal of the offending thrombus directly. This is accomplished by inserting a catheter into the femoral artery
Femoral artery
The femoral artery is a general term comprising a few large arteries in the thigh. They begin at the inguinal ligament and end just above the knee at adductor canal or Hunter's canal traversing the extent of the femur bone....

, directing it into the cerebral circulation
Cerebral circulation
Cerebral circulation refers to the movement of blood through the network of blood vessels supplying the brain. The arteries deliver oxygenated blood, glucose and other nutrients to the brain and the veins carry deoxygenated blood back to the heart, removing carbon dioxide, lactic acid, and other...

, and deploying a corkscrew-like device to ensnare the clot, which is then withdrawn from the body. Mechanical embolectomy devices have been demonstrated effective at restoring blood flow in patients who were unable to receive thrombolytic drugs
Thrombolysis
Thrombolysis is the breakdown of blood clots by pharmacological means. It is colloquially referred to as clot busting for this reason...

 or for whom the drugs were ineffective, though no differences have been found between newer and older versions of the devices. The devices have only been tested on patients treated with mechanical clot embolectomy within eight hours of the onset of symptoms.

Angioplasty
Angioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...

 and stent
Stent
In the technical vocabulary of medicine, a stent is an artificial 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow...

ing have begun to be looked at as possible viable options in treatment of acute cerebral ischaemia. In a systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...

 of six uncontrolled, single-center trials, involving a total of 300 patients, of intra-cranial stenting in symptomatic intracranial arterial stenosis, the rate of technical success (reduction to stenosis of <50%) ranged from 90-98%, and the rate of major peri-procedural complications ranged from 4-10%. The rates of restenosis and/or stroke following the treatment were also favorable. This data suggests that a large, randomized controlled trial
Randomized controlled trial
A randomized controlled trial is a type of scientific experiment - a form of clinical trial - most commonly used in testing the safety and efficacy or effectiveness of healthcare services or health technologies A randomized controlled trial (RCT) is a type of scientific experiment - a form of...

 is needed to more completely evaluate the possible therapeutic advantage of this treatment.
If studies show carotid stenosis, and the patient has residual function in the affected side, carotid endarterectomy
Carotid endarterectomy
Carotid endarterectomy is a surgical procedure used to prevent stroke, by correcting stenosis in the common carotid artery...

 (surgical removal of the stenosis) may decrease the risk of recurrence if performed rapidly after cerebral infarction. Carotid endarterectomy
Carotid endarterectomy
Carotid endarterectomy is a surgical procedure used to prevent stroke, by correcting stenosis in the common carotid artery...

 is also indicated to decrease the risk of cerebral infarction for symptomatic carotid stenosis (>70 to 80 reduction in diameter).
In tissue losses that are not immediately fatal, the best course of action is to make every effort to restore impairments through physical therapy
Physical therapy
Physical therapy , often abbreviated PT, is a health care profession. Physical therapy is concerned with identifying and maximizing quality of life and movement potential within the spheres of promotion, prevention, diagnosis, treatment/intervention,and rehabilitation...

, speech therapy and exercise.
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