Stroke is the rapidly developing loss of brain functions due to a disturbance in the blood vessels supplying blood to the brain. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The International Statistical Classification of Diseases and Related Health Problems 10th Revision ( ICD -10) is a coding of diseases and signs symptoms abnormal findings I00-I99 - Diseases of the Circulatory system (I00-I02 Acute rheumatic fever ( Rheumatic fever without mention of Heart I00-I99 - Diseases of the Circulatory system (I00-I02 Acute rheumatic fever ( Rheumatic fever without mention of Heart The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. The Mendelian Inheritance in Man project is a Database that catalogues all the known Diseases with a genetic component, and—when possible—links them The Diseases Database is a free Website that provides information about the relationships between medical conditions Symptoms, and Medications. MedlinePlus, with the MedlinePlus Medical Encyclopedia, is a website network containing Health information from the world's largest medical Library eMedicine is an online clinical medical knowledge base that was founded in 1996 by Scott Plantz and Richard Lavely two medical doctors Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books This can be due to ischemia (lack of blood supply) caused by thrombosis or embolism, or due to a hemorrhage. In Medicine, ischemia ( Greek ισχαιμία, isch- is restriction hema or haema is Blood) is a restriction Thrombosis is the formation of a blood Clot ( Thrombus) inside a Blood vessel, obstructing the flow of Blood through the Circulatory In Medicine, an embolism occurs when an object (the embolus, plural emboli) migrates from one part of the Body (through circulation Bleeding, technically known as hemorrhaging / haemorrhaging (see American and British spelling differences) is the loss of Blood from ^[1] In medicine, a stroke, fit, or faint is sometimes referred to as an ictus [cerebri], from the Latin icere ("to strike"), especially prior to a definitive diagnosis. In the past, stroke was referred to as cerebrovascular accident or CVA, but the term "stroke" is now preferred.

Stroke is a medical emergency and can cause permanent neurological damage, complications and death if not promptly diagnosed and treated. A medical emergency is an Injury or Illness that is acute and poses an immediate risk to a person's life or long term health It is the third leading cause of death in the United States. Death is the termination of the biological functions that define living Organisms It refers both to a specific It is the leading cause of adult disability in the United States and Europe. It is the number two cause of death world-wide and may soon become the leading cause of death worldwide. ^[2] Risk factors for stroke include advanced age, hypertension (high blood pressure), previous stroke or transient ischemic attack (TIA), diabetes, high cholesterol, cigarette smoking, atrial fibrillation, the contraceptive pill, migraine with aura, and thrombophilia (a tendency to thrombosis), patent foramen ovale and several rarer disorders. Old age consists of ages nearing or surpassing the Average life span of Human beings and thus the end of the human life cycle. Hypertension, also referred to as high blood pressure, HTN or HPN, is a medical condition in which the Blood pressure is chronically elevated A transient ischemic attack ( TIA, often colloquially referred to as “ mini stroke ” is caused by the changes in the blood supply to a particular area of the Diabetes mellitus (ˌdaɪəˈbiːtiːz or /ˌdaɪəˈbiːtəs/ /məˈlaɪtəs/ or /ˈmɛlətəs/ often referred to simply as diabetes ( Ancient Greek: grc Hypercholesterolemia (literally high blood cholesterol is the presence of high levels of Cholesterol in the blood. Atrial fibrillation ( AF or afib) is a Cardiac arrhythmia (abnormal heart rhythm that involves the two upper chambers ( atria) of the Heart Migraine is a neurological Syndrome characterized by altered bodily experiences painful headaches and nausea Thrombophilia is the propensity to develop Thrombosis (blood clots due to an abnormality in the system of Coagulation. Atrial septal defect ( ASD) is a form of congenital heart defect that enables blood flow between the left and right atria via the Interatrial septum. High blood pressure is the most important modifiable risk factor of stroke. A risk factor is a variable associated with an increased risk of Disease or Infection.

The traditional definition of stroke, devised by the World Health Organization in the 1970s,^[3] is a "neurological deficit of cerebrovascular cause that persists beyond 24 hours or is interrupted by death within 24 hours". This definition was supposed to reflect the reversibility of tissue damage and was devised for the purpose, with the time frame of 24 hours being chosen arbitrarily. The 24-hour limit divides stroke from transient ischemic attack, which is a related syndrome of stroke symptoms that resolve completely within 24 hours. With the availability of treatments that, when given early, can reduce stroke severity, many now prefer alternative concepts, such as brain attack and acute ischemic cerebrovascular syndrome (modeled after heart attack and acute coronary syndrome respectively), that reflect the urgency of stroke symptoms and the need to act swiftly. Myocardial infarction ( MI or AMI for acute myocardial infarction) also known as a heart attack, occurs when the blood supply An acute coronary syndrome (ACS is a set of signs and symptoms ( Syndrome) related to the Heart. ^[4]

Stroke is occasionally treated with thrombolysis ("clot-buster"), but usually with supportive care (physiotherapy and occupational therapy) and secondary prevention with antiplatelet drugs (aspirin and often dipyridamole), blood pressure control, statins and anticoagulation (in selected patients). Thrombolysis is the breakdown ( lysis) of blood clots by pharmacological means Occupational Therapy, often abbreviated "OT", is the "use of productive or creative activity in the treatment or rehabilitation of physically cognitively or Aspirin, or acetylsalicylic acid (ASA (əˌsɛtɨlsælɨˌsɪlɨk ˈæsɨd is a Salicylate drug, often used as an Analgesic to relieve Dipyridamole is a drug that inhibits thrombus formation when given chronically and causes Vasodilation when given at high doses over short time The statins (or HMG-CoA reductase inhibitors) form a class of hypolipidemic drugs used to lower Cholesterol levels in people with or at risk of Cardiovascular An anticoagulant is a substance that prevents coagulation; that is it stops Blood from clotting ^[5]

Classification

A slice of brain from the autopsy of a person who suffered an acute middle cerebral artery (MCA) stroke

Strokes can be classified into two major categories: ischemic and hemorrhagic. The middle cerebral artery (MCA is one of the three major paired arteries that supplies Blood to the Brain. Ischemia is due to interruption of the blood supply, while hemorrhage is due to rupture of a blood vessel or an abnormal vascular structure. In Medicine, ischemia ( Greek ισχαιμία, isch- is restriction hema or haema is Blood) is a restriction The blood vessels are part of the Circulatory system and function to transport Blood throughout the body 80% of strokes are due to ischemia; the remainder are due to hemorrhage.

Ischemic stroke

In an ischemic stroke, blood supply to part of the brain is decreased, leading to dysfunction and necrosis of the brain tissue in that area. Necrosis (in Greek Νεκρός = "dead" is the name given to unnatural Death of cells and living tissue. There are four reasons why this might happen: thrombosis (obstruction of a blood vessel by a blood clot forming locally), embolism (idem due to a embolus from elsewhere in the body, see below), systemic hypoperfusion (general decrease in blood supply, e. A thrombus, or blood clot, is the final product of the Blood coagulation step in Hemostasis. g. in shock) and venous thrombosis. Cerebral venous sinus thrombosis ( CVST) is a rare form of Stroke that results from Thrombosis (a blood clot of the Dural venous sinuses, which Stroke without an obvious explanation is termed "cryptogenic" (of unknown origin).

A widely used classification of ischemic stroke is the Bamford classification, introduced in 1991. This relies on the presenting symptoms and physical examination to identify the area of the brain affected, and can be used to predict prognosis as well as underlying etiology:^[6][7]

• Total anterior circulation infarct (TACI)
• Partial anterior circulation infarct (PACI)
• Lacunar infarct (LACI)
• Posterior circulation infarct (POCI)

Each of these gives a stereotypical clinical picture. A Total Anterior Circulation Infarct ( TACI) is a type of Ischemic stroke affecting the entire Anterior Circulation supplying one side of Partial Anterior Circulation Infarct ( PACI) is a type of Ischemic stroke affecting part of the Anterior Circulation supplying one side of the A Posterior Circulation Infarct ( POCI) is a type of Ischemic stroke affecting the Posterior Circulation supplying one side of the Brain Before the location of the infarction has been confirmed by diagnostic imaging (e. g. CT scan), they may be referred to as Total Anterior Circulatory Syndrome, and so on (TACS, PACS, LACS, POCS). Computed tomography (CT is a Medical imaging method employing Tomography.

Thrombotic stroke

In thrombotic stroke, a thrombus (blood clot) usually forms around atherosclerotic plaques. Atherosclerosis is a Disease affecting arterial Blood vessels It is a chronic inflammatory response in the walls of arteries in large part due to the accumulation Since blockage of the artery is gradual, onset of symptomatic thrombotic strokes is slower. A thrombus itself (even if non-occluding) can lead to an embolic stroke (see below) if the thrombus breaks off, at which point it is called an "embolus". Thrombotic stroke can be divided into two types depending on the type of vessel the thrombus is formed on:

• Large vessel disease involves the common and internal carotids, vertebral, and the Circle of Willis. In Human anatomy, the internal carotid artery is a major Artery of the head and neck that helps supply blood to the Brain. The vertebral arteries are branches of the subclavian arteries. The circle of Willis (also called the cerebral arterial circle or arterial circle of Willis) is a circle of arteries that supply blood to the Brain Diseases that may form thrombi in the large vessels include (in descending incidence): atherosclerosis, vasoconstriction (tightening of the artery), aortic, carotid or vertebral artery dissection, various inflammatory diseases of the blood vessel wall (Takayasu arteritis, giant cell arteritis, vasculitis), noninflammatory vasculopathy, Moyamoya disease and fibromuscular dysplasia. Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels particularly the large Arteries, Arterioles Carotid artery dissection is a significant cause of Stroke in young patients Vertebral artery dissection is the development of dissection (a flap-like tear in the Vertebral artery. Takayasu's Arteritis is an inflammatory disease of unknown Etiology that affects the Aorta and its branches Temporal arteritis, also called giant cell arteritis ( GCA) is an inflammatory disease of Blood vessels (most commonly large and medium arteries Vasculitis (plural vasculitides) a group of diseases featuring Inflammation of the wall of Blood vessels including veins ( Phlebitis) arteries Moyamoya disease is an extremely rare disorder in most parts of the world Fibromuscular dysplasia (FMD or fibromuscular dysplasia of arteries, is a disease that can cause Stenosis of the renal arteries, carotid arteries
• Small vessel disease involves the smaller arteries inside the brain: branches of the circle of Willis, middle cerebral artery, stem, and arteries arising from the distal vertebral and basilar artery. The circle of Willis (also called the cerebral arterial circle or arterial circle of Willis) is a circle of arteries that supply blood to the Brain In Human anatomy, the basilar artery is one of the arteries that supplies the Brain with oxygen-rich blood Diseases that may form thrombi in the small vessels include (in descending incidence): lipohyalinosis (build-up of fatty hyaline matter in the blood vessel as a result of high blood pressure and aging) and fibrinoid degeneration (stroke involving these vessels are known as lacunar infarcts) and microatheroma (small atherosclerotic plaques).

Sickle cell anemia, which can cause blood cells to clump up and block blood vessels, can also lead to stroke. Sickle-cell disease or sickle-cell anaemia (or anemia) is a Blood disorder characterized by Red blood cells that assume an abnormal rigid A blood cell (also called blood corpuscle) is any cell of any type normally found in Blood. Stroke is the second leading killer of people under 20 who suffer from sickle-cell anemia. ^[8]

Embolic stroke

Embolic stroke refers to the blockage of an artery by an embolus, a traveling particle or debris in the arterial bloodstream originating from elsewhere. In Medicine, an embolism occurs when an object (the embolus, plural emboli) migrates from one part of the Body (through circulation An embolus is most frequently a thrombus, but it can also be a number of other substances including fat (e. Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water g. from bone marrow in a broken bone), air, cancer cells or clumps of bacteria (usually from infectious endocarditis). Bone marrow is the flexible tissue found in the hollow interior of Bones In adults marrow in large bones produces new Blood cells It constitutes 4% of A bone fracture (sometimes abbreviated # or Fx or Fx) is a medical condition in which a Bone is cracked or broken Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Endocarditis is an Inflammation of the inner layer of the Heart, the Endocardium.

Because an embolus arises from elsewhere, local therapy only solves the problem temporarily. Thus, the source of the embolus must be identified. Because the embolic blockage is sudden in onset, symptoms usually are maximal at start. Also, symptoms may be transient as the embolus is partially resorbed and moves to a different location or dissipates altogether.

Emboli most commonly arise from the heart (especially in atrial fibrillation) but may originate from elsewhere in the arterial tree. The heart is a muscular organ in all Vertebrates responsible for pumping Blood through the Blood vessels by repeated rhythmic In paradoxical embolism, a deep vein thrombosis embolises through an atrial or ventricular septal defect in the heart into the brain. A paradoxical embolism is a kind of Stroke or other form of arterial thrombosis caused by Embolism of a Thrombus ( Blood clot) of venous origin In Medicine, deep vein thrombosis (also known as deep-vein thrombosis or deep venous thrombosis and usually abbreviated as DVT) is the formation Atrial septal defect ( ASD) is a form of congenital heart defect that enables blood flow between the left and right atria via the Interatrial septum. A ventricular septal defect ( VSD) is a defect in the Ventricular septum, the wall dividing the left and right ventricles of the Heart.

Cardiac causes can be distinguished between high- and low-risk:^[9]

• High risk: atrial fibrillation and paroxysmal atrial fibrillation, rheumatic disease of the mitral or aortic valve disease, artificial heart valves, known cardiac thrombus of the atrium or vertricle, sick sinus syndrome, sustained atrial flutter, recent myocardial infarction, chronic myocardial infarction together with ejection fraction <28 percent, symptomatic congestive heart failure with ejection fraction <30 percent, dilated cardiomyopathy, Libman-Sacks endocarditis, Marantic endocarditis, infective endocarditis, papillary fibroelastoma, left atrial myxoma and coronary artery bypass graft (CABG) surgery
• Low risk/potential: calcification of the annulus (ring) of the mitral valve, patent foramen ovale (PFO), atrial septal aneurysm, atrial septal aneurysm with patent foramen ovale, left ventricular aneurysm without thrombus, isolated left atrial "smoke" on echocardiography (no mitral stenosis or atrial fibrillation), complex atheroma in the ascending aorta or proximal arch

Systemic hypoperfusion

Systemic hypoperfusion is the reduction of blood flow to all parts of the body. Atrial fibrillation ( AF or afib) is a Cardiac arrhythmia (abnormal heart rhythm that involves the two upper chambers ( atria) of the Heart Rheumatic fever is an Autoimmune inflammatory Disease which may develop two to three weeks after a Group A streptococcal infection (such as The miter valve (also known as the bicuspid valve or left atrioventricular valve) is a dual flap (bi = 2 valve in the Heart that lies between An artificial heart valve is a device which is implanted in the heart of patients who suffer from valvular diseases in their heart Sick sinus syndrome, also called Sinus node dysfunction, is a group of abnormal heart rhythms ( Arrhythmias presumably caused by a malfunction of the Sinus Atrial flutter is an abnormal heart rhythm that occurs in the atria of the Heart. In cardiovascular physiology, ejection fraction ( Ef) is the fraction of Blood pumped out of a ventricle with each heart beat Heart failure is a Cardiac condition that occurs when a problem with the structure or function of the Heart impairs its ability to supply Dilated cardiomyopathy or DCM, also known as congestive cardiomyopathy, is a condition in which the Heart becomes weakened and enlarged and cannot pump Libman-Sacks endocarditis is a form of nonbacterial Endocarditis that is seen in systemic lupus erythematosus. Endocarditis is an Inflammation of the inner layer of the Heart, the Endocardium. A papillary fibroelastoma is a primary tumor of the heart that typically involves one of the valves of the Heart. left atrial myxoma is a benign tumor located in the left upper chamber of the heart ( atrium) on the wall that separates the left chamber from the right (the atrial septum Coronary artery bypass surgery, also coronary artery bypass graft surgery, and colloquially heart bypass or bypass surgery is a surgical procedure An echocardiogram is a Sonography of the Heart. Also known as a cardiac ultrasound it uses standard ultrasound techniques to image two-dimensional slices of Mitral Stenosis is a Valvular heart disease characterized by the narrowing of the orifice of the Mitral valve of the Heart. The ascending aorta is a portion of the Aorta commencing at the upper part of the base of the left ventricle on a level with the lower border of the third costal cartilage behind It is most commonly due to cardiac pump failure from cardiac arrest or arrhythmias, or from reduced cardiac output as a result of myocardial infarction, pulmonary embolism, pericardial effusion, or bleeding. Cardiopulmonary bypass (CPB is a technique that temporarily takes over the function of the Heart and Lungs during surgery maintaining the circulation of blood A cardiac arrest, also known as cardiorespiratory arrest, cardiopulmonary arrest or circulatory arrest, is the abrupt cessation of normal circulation of Cardiac output (Q is the volume of blood being pumped by the Heart, in particular by a ventricle in a minute Pulmonary embolism (PE is a blockage of the Pulmonary artery or one of its branches usually occurring when a venous Thrombus (blood clot from a vein Pericardial effusion ("fluid around the heart" is an abnormal accumulation of fluid in the Pericardial cavity. Hypoxemia (low blood oxygen content) may precipitate the hypoperfusion. Chronic Hypoxia is a pathological condition in which the body as a whole ( generalized hypoxia) or region of the body ( tissue hypoxia) is deprived of adequate Because the reduction in blood flow is global, all parts of the brain may be affected, especially "watershed" areas - border zone regions supplied by the major cerebral arteries. Blood flow to these areas does not necessarily stop, but instead it may lessen to the point where brain damage can occur. This phenomenon is also referred to as "last meadow" to point to the fact that in irrigation the last meadow receives the least amount of water.

Venous thrombosis

Cerebral venous sinus thrombosis leads to stroke due to locally increased venous pressure, which exceeds the pressure generated by the arteries. Cerebral venous sinus thrombosis ( CVST) is a rare form of Stroke that results from Thrombosis (a blood clot of the Dural venous sinuses, which Infarcts are more likely to undergo hemorrhagic transformation (leaking of blood into the damaged area) than other types of ischemic stroke.

Hemorrhagic stroke

Main articles: Intracranial hemorrhage and intracerebral hemorrhage

CT scan showing an intracerebral hemorrhage. An intracranial hemorrhage is a Hemorrhage, or bleeding within the Skull. A cerebral hemorrhage (or intracerebral hemorrhage, ICH) is a subtype of Intracranial hemorrhage that occurs within the Brain tissue itself

Intracranial hemorrhage is the accumulation of blood anywhere within the skull vault. A distinction is made between intra-axial hemorrhage (blood inside the brain) and extra-axial hemorrhage (blood inside the skull but outside the brain). A cerebral hemorrhage (or intracerebral hemorrhage, ICH) is a subtype of Intracranial hemorrhage that occurs within the Brain tissue itself An intracranial hemorrhage is a Hemorrhage, or bleeding within the Skull. Intra-axial hemorrhage is due to intraparenchymal hemorrhage or intraventricular hemorrhage (blood in the ventricular system). An intraventricular hemorrhage (or "IVH" is a bleeding of the brain's Ventricular system, where the Cerebrospinal fluid is produced and circulates through The main types of extra-axial hemorrhage are epidural hematoma (bleeding between the dura mater and the skull), subdural hematoma (in the subdural space) and subarachnoid hemorrhage (between the arachnoid mater and pia mater). Epidural or extradural hematoma is a type of Traumatic brain injury (TBI in which a buildup of blood occurs between the Dura mater (the tough outer The dura mater (from the Latin "hard mother" or pachymeninx, is the tough and inflexible outermost of the three layers of the Meninges surrounding the A subdural Hematoma (Subdural haematoma (SDH is a form of Traumatic brain injury in which Blood gathers between the dura (the outer protective The subdural space (or subdural cavity) is an artificial space created by the separation of the Arachnoid mater from the Dura mater as the result of trauma Subarachnoid hemorrhage ( SAH,) or subarachnoid haemorrhage in British English, is Bleeding into the Subarachnoid space —the The arachnoid mater is one of the three Meninges, the membranes that cover the Brain and Spinal cord. The pia mater (Latin "tender mother" itself a translation from Arabic) is the delicate innermost layer of the Meninges - the membranes surrounding the Most of the hemorrhagic stroke syndromes have specific symptoms (e. g. headache, previous head injury). A headache ( cephalalgia in medical terminology is a condition of pain in the Head; sometimes Neck or upper back pain may also be interpreted Traumatic brain injury. THIS PAGE IS FOR INFORMATION ON HEAD INJURY (NOT SPECIFICALLY THE BRAIN--> Head injury is

Intracerebral hemorrhage (ICH) is bleeding directly into the brain tissue, forming a gradually enlarging hematoma (pooling of blood). A cerebral hemorrhage (or intracerebral hemorrhage, ICH) is a subtype of Intracranial hemorrhage that occurs within the Brain tissue itself A hematoma, or haematoma, is a collection of Blood outside the blood vessels generally the result of Hemorrhage, or more specifically Internal bleeding It generally occurs in small arteries or arterioles and is commonly due to hypertension, trauma, bleeding disorders, amyloid angiopathy, illicit drug use (e. Haemophilia (also spelled as hemophilia Cerebral amyloid angiopathy, also known as congophilic angiopathy, is a form of Angiopathy in which Amyloid deposits in the walls of the blood Drugs can be used in many different ways as detailed below Medication See also Medication People can use drugs to relieve pain or discomfort or to cure g. amphetamines or cocaine), and vascular malformations. Cocaine ( benzoylmethyl ecgonine) is a Crystalline Tropane Alkaloid that is obtained from the leaves of the Coca plant The hematoma enlarges until pressure from surrounding tissue limits its growth, or until it decompresses by emptying into the ventricular system, CSF or the pial surface. The ventricular system is a set of structures in the Brain continuous with the Central canal of the Spinal cord. Cerebrospinal fluid ( CSF) Liquor cerebrospinalis, is a clear Bodily fluid that occupies the Subarachnoid space and the Ventricular system A third of intracerebral bleed is into the brain's ventricles. ICH has a mortality rate of 44 percent after 30 days, higher than ischemic stroke or even the very deadly subarachnoid hemorrhage. Mortality rate is a measure of the number of Deaths (in general or due to a specific cause in some population scaled to the size of that population per unit time

Signs and symptoms

Stroke symptoms typically develop rapidly (seconds to minutes). A symptom' (from Greek σύμπτωμα, "accident misfortune that which befalls" from συμπίπτω, "I befall" from The symptoms of a stroke are related to the anatomical location of the damage; nature and severity of the symptoms can therefore vary widely. Ischemic strokes usually only affect regional areas of the brain perfused by the blocked artery. Hemorrhagic strokes can affect local areas, but often can also cause more global symptoms due to bleeding and increased intracranial pressure. On the basis of the history and neurological examination, as well as the presence of risk factors, a doctor can rapidly diagnose the anatomical nature of the stroke (i. A neurological examination is the assessment of sensory neuron and motor responses especially Reflexes to determine whether the Nervous system e. which part of the brain is affected), even if the exact cause is not yet known.

Pre-hospital care professionals in the United Kingdom will typically want to identify stroke risk very rapidly. If they suspect a stroke, they will typically use the FAST test to assess likelihood:

• Face - look to see if there is any drooping or loss of muscle tone on the face
• Arm - ask the patient to close their eyes and hold both arms out straight for 30 seconds - in a patient with a stroke, you might see one arm tending to slowly move down
• Speech - listen to see if you can hear any slurring of the speech not otherwise explained (e. g. alcohol) and see if they can answer simple questions (where are you?, what's your name?, what day of the week is it?)
• Test all three - given that any one of the four signs might be present, all three have to be tested (and documented)

If the area of the brain affected contains one of the three prominent Central nervous system pathways—the spinothalamic tract, corticospinal tract, and dorsal column (medial lemniscus), symptoms may include:

• hemiplegia and muscle weakness of the face
• numbness
• reduction in sensory or vibratory sensation

In most cases, the symptoms affect only one side of the body (unilateral). A neural pathway is a Neural tract connecting one part of the Nervous system with another usually consisting of bundles of elongated Myelin -insulated The spinothalamic tract is a sensory pathway originating in the spinal cord The corticospinal or pyramidal tract is a massive collection of Axons that travel between the Cerebral cortex of the Brain and the Spinal The posterior column-medial lemniscus pathway is the sensory pathway responsible for transmitting fine touch, Vibration and The medial lemniscus, also known as Reil's band or Reil's ribbon, is a pathway in the Brainstem that carries sensory information from the gracile Hemiplegia is a condition in which one-half of a patient's body is paralyzed. Central facial palsy, (also called colloquially central seven) is a symptom or finding characterized by Paralysis or Paresis of the lower half of one side Unilateralism ("one+side -ism " is any doctrine or agenda that supports one-sided action The defect in the brain is usually on the opposite side of the body (depending on which part of the brain is affected). However, the presence of any one of these symptoms does not necessarily suggest a stroke, since these pathways also travel in the spinal cord and any lesion there can also produce these symptoms. The spinal cord is a long thin tubular bundle of Nerves that is an extension of the Central nervous system from the brain and is enclosed in and protected

In addition to the above CNS pathways, the brainstem also consists of the 12 cranial nerves. The brain stem (or brainstem) is the lower part of the Brain, adjoining and structurally continuous with the Spinal cord. Cranial nerves are Nerves that emerge directly from the Brain stem in contrast to Spinal nerves which emerge from segments of the Spinal cord. A stroke affecting the brainstem therefore can produce symptoms relating to deficits in these cranial nerves:

• altered smell, taste, hearing, or vision (total or partial)
• drooping of eyelid (ptosis) and weakness of ocular muscles
• decreased reflexes: gag, swallow, pupil reactivity to light
• decreased sensation and muscle weakness of the face
• balance problems and nystagmus
• altered breathing and heart rate
• weakness in sternocleidomastoid muscle with inability to turn head to one side
• weakness in tongue (inability to protrude and/or move from side to side)

If the cerebral cortex is involved, the CNS pathways can again be affected, but also can produce the following symptoms:

• aphasia (inability to speak or understand language from involvement of Broca's or Wernicke's area)
• apraxia (altered voluntary movements)
• visual field defect
• memory deficits (involvement of temporal lobe)
• hemineglect (involvement of parietal lobe)
• disorganized thinking, confusion, hypersexual gestures (with involvement of frontal lobe)
• anosognosia (persistent denial of the existence of a, usually stroke-related, deficit)

If the cerebellum is involved, the patient may have the following:

• trouble walking
• altered movement coordination
• vertigo and or disequilibrium

Loss of consciousness, headache, and vomiting usually occurs more often in hemorrhagic stroke than in thrombosis because of the increased intracranial pressure from the leaking blood compressing on the brain. Ptosis is an abnormally low position (drooping of the upper Eyelid. The extraocular muscles are the six Muscles that control the movements of the (human eye. A balance disorder is a disturbance that causes an individual to feel unsteady giddy woozy or have a sensation of movement spinning or floating Nystagmus is a type of eye movement characterized by alternating slow phase movements in one direction and Saccade -like quick phases in the other direction In Human Anatomy, the sternocleidomastoid (pronounced /ˌstɚ The cerebral cortex is a structure within the Brain that plays a key role in Memory, Attention, perceptual Awareness, Thought, Broca's area is a section of the human brain that is involved in Language processing, speech or sign production and comprehension Wernicke's area is a part of the Human cerebrum that forms part of the cortex, on the posterior section of the Superior temporal gyrus, encircling the Apraxia is a Neurological disorder characterized by loss of the ability to execute or carry out learned purposeful movements despite having the desire and the physical ability The term visual field is sometimes used as a Synonym to Field of view, though they do not designate the same thing The temporal lobes are parts of the cerebrum that are involved in speech, Memory, and Hearing. Hemispatial neglect, also called hemiagnosia, hemineglect, unilateral neglect, spatial neglect or neglect syndrome is a Neurological The parietal lobe is a lobe in the Brain. It is positioned above (superior to the Occipital lobe and behind (posterior to the Frontal lobe. Hypersexuality is the desire to engage in Human sexual behavior at a level high enough to be considered clinically significant The cerebellum ( Latin: "little brain" is a region of the Brain that plays an important role in the integration of sensory perception Vertigo (from the Latin vertere, to turn and the suffix -igo, a condition i See also Unconscious mind. Unconsciousness, more appropriately referred to as loss of Consciousness or lack of consciousness is

If symptoms are maximal at onset, the cause is more likely to be a subarachnoid hemorrhage or an embolic stroke.

Pathophysiology

Ischemic stroke occurs due to a loss of blood supply to part of the brain, initiating the ischemic cascade. The ischemic (ischaemic cascade is a series of biochemical reactions that take place in the Brain and other aerobic tissues after seconds to minutes of Ischemia (inadequate Brain tissue ceases to function if deprived of oxygen for more than 60 to 90 seconds and after a few hours will suffer irreversible injury possibly leading to death of the tissue, i. e. , infarction. In Medicine, an infarction is the process resulting in a Macroscopic area of necrotic tissue in some organ caused by loss of adequate Blood supply Atherosclerosis may disrupt the blood supply by narrowing the lumen of blood vessels leading to a reduction of blood flow, by causing the formation of blood clots within the vessel, or by releasing showers of small emboli through the disintegration of atherosclerotic plaques. In Medicine, an embolism occurs when an object (the embolus, plural emboli) migrates from one part of the Body (through circulation Embolic infarction occurs when emboli formed elsewhere in the circulatory system, typically in the heart as a consequence of atria fibriliation, or in the carotid arteries. These break off, enter the cerebral circulation, then lodge in and occlude brain blood vessels.

Due to collateral circulation, within the region of brain tissue affected by ischemia there is a spectrum of severity. An anastomosis (plural anastomoses, from gr ἀναστόμωσις communicating opening) is a Network of streams that both branch out and reconnect Thus, part of the tissue may immediately die while other parts may only be injured and could potentially recover. The ischemia area where tissue might recover is referred to as the ischemic penumbra. For other uses of the word "umbra" see Umbra (disambiguation.

As oxygen or glucose becomes depleted in ischemic brain tissue, the production of high energy phosphate compounds such as adenosine triphosphate (ATP) fails leading to failure of energy dependent processes (such as ion pumping) necessary for tissue cell survival. High-energy phosphate can mean one of two things The phosphate-phosphate bonds formed when compounds such as Adenosine diphosphate and Adenosine triphosphate This sets off a series of interrelated events that result in cellular injury and death. A major cause of neuronal injury is release of the excitatory neurotransmitter glutamate. The concentration of glutamate outside the cells of the nervous system is normally kept low by so-called uptake carriers, which are powered by the concentration gradients of ions (mainly Na⁺) across the cell membrane. However, stroke cuts off the supply of oxygen and glucose which powers the ion pumps maintaining these gradients. As a result the transmembrane ion gradients run down, and glutamate transporters reverse their direction, releasing glutamate into the extracellular space. Glutamate acts on receptors in nerve cells (especially NMDA receptors), producing an influx of calcium which activates enzymes that digest the cells' proteins, lipids and nuclear material. Calcium influx can also lead to the failure of mitochondria, which can lead further toward energy depletion and may trigger cell death due to apoptosis. In Cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed Organelle found in most eukaryotic cells.

Ischaemia also induces production of oxygen free radicals and other reactive oxygen species. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell Reactive oxygen species (ROS are ions or very small molecules that include Oxygen Ions free radicals, and Peroxides both inorganic and These react with and damage a number of cellular and extracellular elements. Damage to the blood vessel lining or endothelium is particularly important. In fact, many antioxidant neuroprotectants such as uric acid and NXY-059 work at the level of the endothelium and not in the brain per se. Uric acid (or urate) is an Organic compound of Carbon, Nitrogen, Oxygen and Hydrogen with the formula C5H4N4O3 Disufenton sodium ( NXY-059) is the disulfonyl derivative of the neuroprotective spintrap Phenylbutynitrone or "PBN" Free radicals also directly initiate elements of the apoptosis cascade by means of redox signaling . Redox signaling is the process wherein Free radicals, Reactive oxygen species (ROS and other electronically-activated species act as messengers in biological systems ^[8]

These processes are the same for any type of ischemic tissue and are referred to collectively as the ischemic cascade. However, brain tissue is especially vulnerable to ischemia since it has little respiratory reserve and is completely dependent on aerobic metabolism, unlike most other organs. Cellular respiration is the set of the metabolic reactions and processes that take place in Organisms cells to convert biochemical energy from

Brain tissue survival can be improved to some extent if one or more of these processes is inhibited. Drugs that scavenge Reactive oxygen species, inhibit apoptosis, or inhibit excitotoxic neurotransmitters, for example, have been shown experimentally to reduce tissue injury due to ischemia. Reactive oxygen species (ROS are ions or very small molecules that include Oxygen Ions free radicals, and Peroxides both inorganic and Agents that work in this way are referred to as being neuroprotective. Until recently, human clinical trials with neuroprotective agents have failed, with the probable exception of deep barbiturate coma. In health care clinical trials are conducted to allow safety and Efficacy data to be collected for new drugs or devices However, more recently NXY-059, the disulfonyl derivative of the radical-scavenging spintrap phenylbutylnitrone, is reported be neuroprotective in stroke. This agent appears to work at the level of the blood vessel lining or endothelium. Unfortunately, after producing favorable results in one large-scale clinical trial, a second trial failed to show favorable results. ^[8]

In addition to injurious effects on brain cells, ischemia and infarction can result in loss of structural integrity of brain tissue and blood vessels, partly through the release of matrix metalloproteases, which are zinc- and calcium-dependent enzymes that break down collagen, hyaluronic acid, and other elements of connective tissue. Hyaluronan (also called hyaluronic acid or hyaluronate) is a non-sulfated Glycosaminoglycan distributed widely throughout connective, epithelial Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, Muscle, and Nervous tissue) Other proteases also contribute to this process. The loss of vascular structural integrity results in a breakdown of the protective blood brain barrier that contributes to cerebral edema, which can cause secondary progression of the brain injury. The blood-brain barrier (BBB is a metabolic or cellular structure in the Central nervous system (CNS that restricts the passage of various chemical substances and microscopic Cerebral edema (cerebral oedema in British English) is an excess accumulation of water in the intracellular and/or extracellular spaces of the Brain.

As is the case with any type of brain injury, the immune system is activated by cerebral infarction and may under some circumstances exacerbate the injury caused by the infarction. Traumatic brain injury (TBI also called intracranial injury, occurs when Physical trauma injures the Brain. An immune system is a collection of mechanisms within an Organism that protects against Disease by identifying and killing Pathogens and Tumor Inhibition of the inflammatory response has been shown experimentally to reduce tissue injury due to cerebral infarction, but this has not proved out in clinical studies. Inflammation ( Latin, inflamatio, to set on fire is the complex biological response of vascular tissues to harmful stimuli such as Pathogens

Hemorrhagic strokes result in tissue injury by causing compression of tissue from an expanding hematoma or hematomas. This can distort and injure tissue. In addition, the pressure may lead to a loss of blood supply to affected tissue with resulting infarction, and the blood released by brain hemorrhage appears to have direct toxic effects on brain tissue and vasculature. ^[8]

Diagnosis

Stroke is diagnosed through several techniques: a neurological examination, CT scans (most often without contrast enhancements) or MRI scans, Doppler ultrasound, and arteriography. Angiography or arteriography is a Medical imaging technique in which an X-ray image is taken to visualize the inside or lumen, of blood vessels The diagnosis of stroke itself is clinical, with assistance from the imaging techniques. Imaging techniques also assist in determining the subtypes and cause of stroke. There is yet no commonly used blood test for the stroke diagnosis itself, though blood tests may be of help in finding out the likely cause of stroke. A blood test is a laboratory analysis performed on a Blood sample that is usually extracted from a Vein in the arm using a needle, or via ^[10]

Physical examination

A systematic review found that acute facial paresis, arm drift, or abnormal speech are the best findings. A systematic review is a Literature review focused on a single question which tries to identify appraise select and synthesize all high quality research evidence relevant to ^[11]

Imaging

For diagnosing ischemic stroke in the emergency setting:^[12]

• CT scans (without contrast enhancements)

sensitivity= 16%

specificity= 96%

• MRI scan

sensitivity= 83%

specificity= 98%

For diagnosing hemorrhagic stroke in the emergency setting:

• CT scans (without contrast enhancements)

sensitivity= 89%

specificity= 100%

• MRI scan

sensitivity= 81%

specificity= 100%

For detecting chronic hemorrhages, MRI scan is more sensitive. ^[13]

For the assessment of stable stroke, nuclear medicine scans SPECT and PET/CT may be helpful. SPECT documents cerebral blood flow and PET with FDG isotope the metabolic activity of the neurons.

Underlying etiology

When a stroke has been diagnosed, various other studies may be performed to determine the underlying etiology. With the current treatment and diagnosis options available, it is of particular importance to determine whether there is a peripheral source of emboli. Test selection may vary, since the cause of stroke varies with age, comorbidity and the clinical presentation. In Medicine, comorbidity (literally "additional Morbidity " is either * The presence of one or more disorders (or diseases in addition to Commonly used techniques include:

• an ultrasound/doppler study of the carotid arteries (to detect carotid stenosis) or dissection of the precerebral arteries
• an electrocardiogram (ECG) and echocardiogram (to identify arrhythmias and resultant clots in the heart which may spread to the brain vessels through the bloodstream)
• a Holter monitor study to identify intermittent arrhythmias
• an angiogram of the cerebral vasculature (if a bleed is thought to have originated from an aneurysm or arteriovenous malformation)
• blood tests to determine hypercholesterolemia, bleeding diathesis and some rarer causes such as homocysteinuria

Prevention

Given the disease burden of stroke, prevention is an important public health concern. In Human anatomy, the common carotid artery is an Artery that supplies the head and neck with Oxygenated blood; it divides in the neck to form the Carotid stenosis is a narrowing of the lumen of the Carotid artery, usually caused by Atherosclerosis. An echocardiogram is a Sonography of the Heart. Also known as a cardiac ultrasound it uses standard ultrasound techniques to image two-dimensional slices of Dysrhythmia redirects here For the American band see Dysrhythmia (band. In Medicine, a Holter monitor (also called an ambulatory electrocardiography device) named after its inventor Dr Angiography or arteriography is a Medical imaging technique in which an X-ray image is taken to visualize the inside or lumen, of blood vessels An aneurysm (or aneurism) is a localized blood-filled dilation (balloon-like bulge of a blood vessel caused by disease or weakening of the vessel wall Cerebral arteriovenous malformation Arteriovenous malformation or AVM in the majority of cases is a Congenital disorder consisting of a connection between In Medicine ( Hematology) bleeding diathesis is an unusual susceptibility to bleeding ( Hemorrhage) due to a defect in the system of Coagulation Homocystinuria, also known as Cystathionine beta synthase deficiency, is an inherited disorder of the Metabolism of the Amino acid Methionine In Medicine, prevention is any activity which reduces the burden of mortality or morbidity from Disease. Public health is "the science and art of preventing disease prolonging life and promoting health through the organised efforts and informed choices of society organisations ^[14] Primary prevention is a lot less effective than secondary prevention (as judged by the number needed to treat to prevent one stroke per year). The number needed to treat (NNT is an epidemiological measure used in assessing the effectiveness of a health-care intervention typically a treatment with Medication ^[14] Recent guidelines detail the evidence for primary prevention in stroke. ^[15] Because stroke may indicate underlying atherosclerosis, it is important to determine the patient's risk for other cardiovascular diseases such as coronary heart disease. Coronary disease (or coronary heart disease) refers to the failure of Coronary circulation to supply adequate circulation to Cardiac muscle and surrounding Conversely, aspirin prevents against first stroke in patients who have suffered a myocardial infarction. ^[16]

The most important modifiable risk factors for stroke are high blood pressure and atrial fibrillation. Other modifiable risk factors include high blood cholesterol levels, diabetes, cigarette smoking^[17][18] (active and passive), heavy alcohol consumption^[19] and drug use,^[20] lack of physical activity, obesity and unhealthy diet. Regularly having more than two drinks a day increases the risk of developing Alcoholism, Alcoholic liver disease, and some forms of Cancer. Obesity is a condition in which excess Body fat has accumulated to such an extent that health may be negatively affected ^[21] Alcohol use could predispose to ischemic stroke, and intracerebral and subarachnoid hemorrhage via multiple mechanisms (for example via hypertension, atrial fibrillation, rebound thrombocytosis and platelet aggregation and clotting disturbances). Thrombocytosis is the presence of high Platelet counts in the Blood, and can be either reactive or primary (also termed essential and caused by a Myeloproliferative Platelets, or Thrombocytes, are small cytoplasmic bodies derived from cells They circulate in the Blood of Mammals and are involved Coagulation is a complex process by which Blood forms Clots It is an important part of Hemostasis (the cessation of blood loss from a damaged vessel whereby ^[22] The drugs most commonly associated with stroke are cocaine, amphetamines causing hemorrhagic stroke, but also over-the-counter cough and cold drugs containing sympathomimetics. Amphetamine, and related drugs such as Methamphetamine are a group of drugs that act by increasing levels of Norepinephrine, Serotonin, and Dopamine Sympathomimetic drugs are substances that mimic the effects of the Catecholamines Epinephrine (adrenaline Norepinephrine (noradrenaline and/or ^[23][24]

No high quality studies have shown the effectiveness of interventions aimed at weight reduction, promotion of regular exercise, reducing alcohol consumption or smoking cessation. Smoking cessation is the effort to stop smoking Tobacco products ^[25] Nonetheless, given the large body of circumstantial evidence, best medical management for stroke includes advise on diet, exercise, smoking and alcohol use. ^[26] Medication or drug therapy is the most common method of stroke prevention; carotid endarterectomy can be a useful surgical method of preventing stroke. Pharmacology (from Greek grc φάρμακον pharmakon, "drug" and grc -λογία -logia) is the study of how Drugs Carotid endarterectomy (CEA is a surgical procedure used to correct Carotid stenosis (narrowing of the Carotid artery lumen by Atheroma) used

Blood pressure

Hypertension accounts for 35-50% of stroke risk. Hypertension, also referred to as high blood pressure, HTN or HPN, is a medical condition in which the Blood pressure is chronically elevated ^[27] Epidemiological studies suggest that even a small blood pressure reduction (5 to 6 mmHg systolic, 2 to 3 mmHg diastolic) would result in 40% fewer strokes. Epidemiology is the study of factors affecting the Health and Illness of populations and serves as the foundation and Logic of interventions made in the ^[28] Lowering blood pressure has been conclusively shown to prevent both ischemic and hemorrhagic strokes. ^[29][30] It is equally important in secondary prevention. ^[31] Even patients older than 80 years and those with isolated systolic hypertension benefit from antihypertensive therapy. In Medicine, systolic hypertension is defined as an elevated Systolic blood pressure. ^[32][33][34] Studies show that intensive antihypertensive therapy results in a greater risk reduction. ^[35] The available evidence does not show large differences in stroke prevention between antihypertensive drugs —therefore, other factors such as protection against other forms of cardiovascular disease should be considered and cost. ^[35][36]

Atrial fibrillation

Patients with atrial fibrillation have a risk of 5% each year to develop stroke, and this risk is even higher in those with valvular atrial fibrillation. ^[37] Depending on the stroke risk, anticoagulation with medications such as coumarins or aspirin is warranted for stroke prevention. Coumarin is a Chemical compound ( Benzopyrone) a Toxin found in many Plants notably in high concentration in the Tonka bean, ^[38]

Blood lipids

High cholesterol levels have been inconsistently associated with (ischemic) stroke. ^[39][30] Statins have been shown to reduce the risk of stroke by about 15%. The statins (or HMG-CoA reductase inhibitors) form a class of hypolipidemic drugs used to lower Cholesterol levels in people with or at risk of Cardiovascular ^[40] Since earlier meta-analyses of other lipid-lowering drugs did not show a decreased risk,^[41] statins might exert there effect through mechanisms other than their lipid-lowering effects. Hypolipidemic agents, or antihyperlipidemic agents, are a diverse group of pharmaceuticals that are used in the treatment of Hyperlipidemias They are called ^[40]

Diabetes mellitus

Patients with diabetes mellitus are 2 to 3 times more likely to develop stroke, and they commonly have hypertension and hyperlipidemia. Intensive disease control has been shown to reduce microvascular complications such as nephropathy and retinopathy but not macrovascular complications such as stroke. ^[42][43]

Anticoagulation drugs

Aspirin or other antiplatelet drugs are highly effective in secondary prevention after a stroke or transient ischemic attack. Low doses of aspirin (for example 75-150 mg) are as effective as high doses but have fewer side-effects; the lowest effective dose remains unknown. ^[44] Thienopyridines (clopidogrel, ticlopidine) are modestly more effective than aspirin and have a decreased risk of gastrointestinal bleeding, but they are more expensive. Clopidogrel is a potent oral antiplatelet agent often used in the treatment of Coronary artery disease, Peripheral vascular disease, and Cerebrovascular Ticlopidine (trade name Ticlid) is an Antiplatelet drug in the Thienopyridine family Gastrointestinal bleeding or gastrointestinal hemorrhage describes every form of Hemorrhage (loss of Blood) in the Gastrointestinal tract ^[45] Their exact role remains controversial. Ticlopidine has more skin rash, diarrhea, neutropenia and thrombotic thrombocytopenic purpura. A rash is a change of the Skin which affects its color appearance or Texture. In Medicine, diarrhea, also spelled diarrhoea (see spelling differences) is frequent loose or liquid Bowel movements Acute diarrhea Neutropenia (adjective neutropenic) from Latin Prefix neutro- and Greek Suffix -πενία (deficiency is Thrombotic thrombocytopenic purpura ( TTP or Moschcowitz disease) is a rare disorder of the blood-coagulation system causing extensive microscopic ^[45] Dipyridamole can be added to aspirin therapy to provide a small additional benefit, even though headache is a common side-effect. Dipyridamole is a drug that inhibits thrombus formation when given chronically and causes Vasodilation when given at high doses over short time ^[46] Low-dose aspirin is also effective for stroke prevention after sustaining a myocardial infarction. ^[16] Oral anticoagulants are not advised for stroke prevention —any benefit is offset by bleeding risk. An anticoagulant is a substance that prevents coagulation; that is it stops Blood from clotting ^[47]

In primary prevention however, antiplatelet drugs did not reduce the risk of ischemic stroke while increasing the risk of major bleeding. ^[48][49] Further studies are needed to investigate a possible protective effect of aspirin against ischemic stroke in women. ^[50][51]

Surgery

Surgical procedures such as carotid endarterectomy or carotid angioplasty can be used to remove significant atherosclerotic narrowing (stenosis) of the carotid artery, which supplies blood to the brain. Angioplasty is the technique of mechanically widening a narrowed or totally obstructed Blood vessel; typically as a result of Atherosclerosis. There is a large body of evidence supporting this procedure in selected cases. ^[26] Endarterectomy for a significant stenosis has been shown to be useful in the secondary prevention after a previous symptomatic stroke. ^[52] Carotid artery stenting has not been shown to be equally useful. ^[53][54] Patients are selected for surgery based on age, gender, degree of stenosis, time since symptoms and patients' preferences. ^[26] Surgery is most efficient when not delayed too long —the risk of recurrent stroke in a patient who has a 50% or greater stenosis is up to 20% after 5 years, but endarterectomy reduces this risk to around 5%. The number of procedures needed to cure one patient was 5 for early surgery (within two weeks after the initial stroke), but 125 if delayed longer than 12 weeks. ^[55][56]

Screening for carotid artery narrowing has not been shown to be a useful screening test in the general population. Screening, in medicine is a strategy used in a Population to detect a Disease in individuals without signs or Symptoms of that disease ^[57] Studies of surgical intervention for carotid artery stenosis without symptoms have shown only a small decrease in the risk of stroke. ^[58][59] To be beneficial, the complication rate of the surgery should be kept > 4%. Even then, for 100 surgeries, 5 patients will benefit by avoiding stroke, 3 will develop stroke despite surgery, 3 will develop stroke or die due to the surgery itself, and 89 will remain stroke-free but would also have done so without intervention. ^[26]

Nutritional and metabolic interventions

Nutrition, specifically the Mediterranean-style diet, has the potential of more than halving stroke risk. ^[60]

With regards to lowering homocysteine, a meta-analysis of previous trials has concluded that lowering homocysteine with folic acid and other supplements may reduce stroke risk. Homocysteine is a Chemical compound with the formula HSCH2CH2CH(NH2CO2H In Statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses Folic acid (also known as Vitamin M and Folacin) and Folate (the Anionic form are forms of the water-soluble Vitamin B9 ^[61] However, the two largest randomized controlled trials included in the meta-analysis had conflicting results. A randomized controlled trial (RCT is a type of scientific Experiment most commonly used in testing the Efficacy or Effectiveness of Healthcare One reported positve results;^[62] whereas the other was negative. ^[63]

Treatment

Early assessment

Early recognition of the signs of stroke is generally regarded as important. Only detailed physical examination and medical imaging provide information on the presence, type, and extent of stroke, and hence hospital attendance — even if the symptoms were brief — is advised. Physical examination or clinical examination is the process by which a Health care provider investigates the body of a Patient for signs Medical imaging refers to the techniques and processes used to create Images of the human body (or parts thereof for clinical purposes ( Medical procedures seeking to

Studies show that patients treated in hospitals with a dedicated Stroke Team or Stroke Unit and a specialized care program for stroke patients have improved odds of recovery.

Ischemic stroke

An ischemic stroke is due to a thrombus (blood clot) occluding a cerebral artery, a patient is given antiplatelet medication (aspirin, clopidogrel, dipyridamole), or anticoagulant medication (warfarin), dependent on the cause, when this type of stroke has been found. A thrombus, or blood clot, is the final product of the Blood coagulation step in Hemostasis. An anticoagulant is a substance that prevents coagulation; that is it stops Blood from clotting Warfarin (also known under the brand names Coumadin, Jantoven, Marevan, and Waran) is an Anticoagulant. Hemorrhagic stroke must be ruled out with medical imaging, since this therapy would be harmful to patients with that type of stroke.

Whether thrombolysis is performed or not, the following investigations are required:

• Stroke symptoms are documented, often using scoring systems such as the National Institutes of Health Stroke Scale, the Cincinnati Stroke Scale, and the Los Angeles Prehospital Stroke Screen. The Cincinnati Stroke Scale is a system used to diagnose the presence of a Stroke in a patient The Cincinnati Stroke Scale is used by emergency medical technicians (EMTs) to determine whether a patient needs transport to a stroke center. The Emergency Medical Technician ( EMT) exists in many countries and is a health care provider trained to provide prehospital emergency medical care
• A CT scan is performed to rule out hemorrhagic stroke
• Blood tests, such as a full blood count, coagulation studies (PT/INR and APTT), and tests of electrolytes, renal function, liver function tests and glucose levels are carried out. Computed tomography (CT is a Medical imaging method employing Tomography. A complete blood count ( CBC) also known as full blood count ( FBC) or full blood exam ( FBE) or blood panel, is Coagulation is a complex process by which Blood forms Clots It is an important part of Hemostasis (the cessation of blood loss from a damaged vessel whereby The prothrombin time ( PT) and its derived measures of prothrombin ratio ( PR) and international normalized ratio ( INR) are measures The partial thromboplastin time' (PTT or activated partial thromboplastin time ( aPTT or APTT) is a performance indicator measuring the efficacy of both the "intrinsic" An electrolyte is any substance containing free Ions that behaves as an electrically conductive medium Renal function, in Nephrology, is an indication of the state of the Kidney and its role in Renal physiology. Liver function tests (LFTs or LFs which include liver enzymes, are groups of Clinical biochemistry laboratory blood assays designed to give information about the Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology.

Other immediate strategies to protect the brain during stroke include ensuring that blood sugar is as normal as possible (such as commencement of an insulin sliding scale in known diabetics), and that the stroke patient is receiving adequate oxygen and intravenous fluids. Blood sugar, used in a physiological context is a misnomer and misleading Diabetes mellitus (ˌdaɪəˈbiːtiːz or /ˌdaɪəˈbiːtəs/ /məˈlaɪtəs/ or /ˈmɛlətəs/ often referred to simply as diabetes ( Ancient Greek: grc Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Intravenous therapy or IV therapy is the giving of Liquid substances directly into a Vein. The patient may be positioned so that his or her head is flat on the stretcher, rather than sitting up, since studies have shown that this increases blood flow to the brain. Additional therapies for ischemic stroke include aspirin (50 to 325 mg daily), clopidogrel (75 mg daily), and combined aspirin and dipyridamole extended release (25/200 mg twice daily).

It is common for the blood pressure to be elevated immediately following a stroke. Blood pressure is also the title of a short story by Damon Runyan in Guys and Dolls and Other Stories Hypertension, also referred to as high blood pressure, HTN or HPN, is a medical condition in which the Blood pressure is chronically elevated Studies indicated that while high blood pressure causes stroke, it is actually beneficial in the emergency period to allow better blood flow to the brain.

If studies show carotid stenosis, and the patient has residual function in the affected side, carotid endarterectomy (surgical removal of the stenosis) may decrease the risk of recurrence if performed rapidly after stroke.

If the stroke has been the result of cardiac arrhythmia with cardiogenic emboli, treatment of the arrhythmia and anticoagulation with warfarin or high-dose aspirin may decrease the risk of recurrence. Stroke prevention treatment for a common arrhythmia, atrial fibrillation, is determined according to the CHADS/CHADS2 system. CHADS score or CHADS2 score is a Clinical prediction rule for estimating the risk of Stroke in patients with non rheumatic

Thrombolysis

In increasing numbers of primary stroke centers, pharmacologic thrombolysis ("clot busting") with the drug tissue plasminogen activator, tPA, is used to dissolve the clot and unblock the artery. Tissue plasminogen activator (abbreviated tPA or PLAT) is a Protein involved in the breakdown of Blood clots Specifically it is a However, the use of tPA in acute stroke is controversial. On one hand, it is endorsed by the American Heart Association and the American Academy of Neurology as the recommended treatment for acute stroke within three hours of onset of symptoms as long as there are not other contraindications (such as abnormal lab values, high blood pressure, or recent surgery). The American Heart Association (AHA is a Non-profit organization in the United States that fosters appropriate This position for tPA is based upon the findings of two studies by one group of investigators^[64] which showed that tPA improves the chances for a good neurological outcome. When administered within the first three hours, 39% of all patients who were treated with tPA had a good outcome at three months, only 26% of placebo controlled patients had a good functional outcome. However, in the NINDS trial 6. 4% of patients with large strokes developed substantial brain hemorrhage as a complication from being given tPA. tPA is often misconstrued as a "magic bullet" and it is important for patients to be aware that despite the study that supports its use, some of the data were flawed and the safety and efficacy of tPA is controversial. A recent study found the mortality to be higher among patients receiving tPA versus those who did not. ^[65] Additionally, it is the position of the American Academy of Emergency Medicine that objective evidence regarding the efficacy, safety, and applicability of tPA for acute ischemic stroke is insufficient to warrant its classification as standard of care. For the English law, see Standard of care in English law. In Tort law, the standard of care is the degree of prudence and caution ^[66] Until additional evidence clarifies such controversies, physicians are advised to use their discretion when considering its use. Given the cited absence of definitive evidence, AAEM believes it is inappropriate to claim that either use or non-use of intravenous thrombolytic therapy constitutes a standard of care issue in the treatment of stroke.

Mechanical thrombectomy

Merci Retriever L5.

Another intervention for acute ischemic stroke is removal of the offending thrombus directly. This is accomplished by inserting a catheter into the femoral artery, directing it into the cerebral circulation, and deploying a corkscrew-like device to ensnare the clot, which is then withdrawn from the body. The femoral artery is a large Artery in the muscles of the Thigh. Cerebral circulation refers to the movement of Blood through the network of Blood vessels supplying the Brain. In August 2004, based on data from the MERCI (Mechanical Embolus Removal in Cerebral Ischemia) Trial, the FDA cleared several of these devices, called the Merci X5 and X6 Retrievers. Brain ischemia (or cerebral ischemia) is an Ischemic condition where the Brain or parts of the brain do not receive enough Blood flow to maintain ^[67][68] The newer generation Merci L5 Retriever was additionally used in the Multi MERCI trial. ^{[69][70][71][72]} Both the MERCI and Multi MERCI trials required the first pass with the Merci Retriever to be initiated within 8 hours of onset of symptoms.

Embolic stroke

Anticoagulation can prevent recurrent stroke. Among patients with nonvalvular atrial fibrillation, anticoagulation can reduce stroke by 60% while antiplatelet agents can reduce stroke by 20%. ^[73]. However, a recent meta-analysis suggests harm from anti-coagulation started early after an embolic stroke. ^[74]

Hemorrhagic stroke

Patients with bleeding into (intracerebral hemorrhage) or around the brain (subarachnoid hemorrhage), require neurosurgical evaluation to detect and treat the cause of the bleeding. A cerebral hemorrhage (or intracerebral hemorrhage, ICH) is a subtype of Intracranial hemorrhage that occurs within the Brain tissue itself Neurosurgery is the surgical discipline focused on treating those central, Peripheral nervous system and spinal column diseases amenable to surgical Anticoagulants and antithrombotics, key in treating ischemic stroke, can make bleeding worse and cannot be used in intracerebral hemorrhage. Patients are monitored and their blood pressure, blood sugar, and oxygenation are kept at optimum levels.

Care and rehabilitation

Stroke rehabilitation is the process by which patients with disabling strokes undergo treatment to help them return to normal life as much as possible by regaining and relearning the skills of everyday living. Stroke rehabilitation, or in more optimistic terms stroke recovery, is the process by which patients with disabling strokes undergo treatment to help them return It also aims to help the survivor understand and adapt to difficulties, prevent secondary complications and educate family members to play a supporting role.

A rehabilitation team is usually multidisciplinary as it involves staff with different skills working together to help the patient. These include nursing staff, physiotherapy, occupational therapy, speech and language therapy, and usually a physician trained in rehabilitation medicine. Speech-language pathology is the study of disorders that affect a person's Speech, Language, cognition voice swallowing ( Dysphagia) and the rehabilitative A physician, medical practitioner or medical doctor who practices Medicine, and is concerned with maintaining or restoring human Health Physical medicine and rehabilitation (PM&R or physiatry, is a branch of Medicine dealing with functional restoration of a person affected by physical disability Some teams may also include psychologists, social workers, and pharmacists since at least one third of the patients manifest post stroke depression. Mental health professional A psychologist is a practitioner of Psychology, the systematic investigation of the mind including Behavior, Cognition, Social work is a discipline involving the application of Social theory and research methods to study and improve the lives of people groups and societies Pharmacists are Health professionals who practice the art and science of Pharmacy. Post-stroke depression (PSD is considered as the most frequent and important neuropsychiatric consequence of Stroke, since approximately one-third of stroke survivors experience Validated instruments such as the Barthel scale may be used to assess the likelihood of a stroke patient being able to manage at home with or without support subsequent to discharge from hospital. The Barthel scale or Barthel ADL index is a scale used to measure performance in basic Activities of Daily Living

Good nursing care is fundamental in maintaining skin care, feeding, hydration, positioning, and monitoring vital signs such as temperature, pulse, and blood pressure. Patient care is part of a Nurse 's role Nurses use the nursing process to assess plan implement and evaluate patient care The skin is the outer covering of living tissue of an animal (or plant Vital signs are measures of various physiological statistics often taken by Health professionals in order to assess the most basic body functions Stroke rehabilitation begins almost immediately.

For most stroke patients, physical therapy (PT) and occupational therapy (OT) are the cornerstones of the rehabilitation process. Often, assistive technology such as a wheelchair, walkers, canes, and orthosis may be beneficial. Assistive technology (AT is a generic term that includes assistive adaptive and rehabilitative devices for people with disabilities and includes the process used in selecting A wheelchair is a wheeled Mobility device in which the user sits An orthosis (sometimes called an orthesis) is a device that is applied externally to a part of the Body to correct Deformity, improve function or relieve PT and OT have overlapping areas of working but their main attention fields are; PT involves re-learning functions as transferring, walking and other gross motor functions. OT focusses on exercises and training to help relearn everyday activities known as the Activities of daily living (ADLs) such as eating, drinking, dressing, bathing, cooking, reading and writing, and toileting. Activities of daily living ( ADLs) are "the things we normally do in daily living including any daily activity we perform for self-care (such as feeding ourselves bathing Speech and language therapy is appropriate for patients with problems understanding speech or written words, problems forming speech and problems with eating (swallowing). Speech-language pathology is the study of disorders that affect a person's Speech, Language, cognition voice swallowing ( Dysphagia) and the rehabilitative

Patients may have particular problems, such as complete or partial inability to swallow, which can cause swallowed material to pass into the lungs and cause aspiration pneumonia. Aspiration pneumonia is Bronchopneumonia that develops due to the entrance of foreign materials that enter the bronchial tree usually oral or gastric contents (including food The condition may improve with time, but in the interim, a nasogastric tube may be inserted, enabling liquid food to be given directly into the stomach. Nasogastric intubation is a medical process involving the insertion of a plastic tube ( nasogastric tube NG tube) through the Nose, past the Throat If swallowing is still unsafe after a week, then a percutaneous endoscopic gastrostomy (PEG) tube is passed and this can remain indefinitely. A percutaneous endoscopic gastrostomy ( PEG) is an endoscopic procedure for placing a tube into the Stomach.

Stroke rehabilitation should be started as immediately as possible and can last anywhere from a few days to over a year. Most return of function is seen in the first few days and weeks, and then improvement falls off with the "window" considered officially by U.S. state rehabilitation units and others to be closed after six months, with little chance of further improvement. A US state is any one of the fifty subnational entities of the United States of America that share Sovereignty with the federal government However, patients have been known to continue to improve for years, regaining and strengthening abilities like writing, walking, running, and talking. Daily rehabilitation exercises should continue to be part of the stroke patient's routine. Complete recovery is unusual but not impossible and most patients will improve to some extent : a correct diet and exercise are known to help the brain to self-recover.

Prognosis

Disability affects 75% of stroke survivors enough to decrease their employability. ^[75] Stroke can affect patients physically, mentally, emotionally, or a combination of the three. The results of stroke vary widely depending on size and location of the lesion. ^[76] Dysfunctions correspond to areas in the brain that have been damaged.

Some of the physical disabilities that can result from stroke include paralysis, numbness, pressure sores, pneumonia, incontinence, apraxia (inability to perform learned movements), difficulties carrying out daily activities, appetite loss, speech loss, vision loss, and pain. Bedsores, more properly known as pressure ulcers or decubitus ulcers, are Lesions caused by many factors such as unrelieved Pressure; friction Pneumonia is an inflammatory illness of the Lung. Frequently it is described as lung Parenchyma / alveolar inflammation and abnormal Vision loss or visual loss is the absence of vision where it existed before which can happen either acutely (i Pain, in the sense of physical pain, is a typical sensory experience that may be described as the unpleasant awareness of a noxious stimulus or bodily harm If the stroke is severe enough, or in a certain location such as parts of the brainstem, coma or death can result. In Medicine, a coma (from the Greek koma, meaning deep sleep is a profound state of Unconsciousness.

Emotional problems resulting from stroke can result from direct damage to emotional centers in the brain or from frustration and difficulty adapting to new limitations. Post-stroke emotional difficulties include anxiety, panic attacks, flat affect (failure to express emotions), mania, apathy, and psychosis. Anxiety is a physiological and psychological state characterized by Cognitive, Somatic, Emotional and Behavioral components Panic attacks are sudden discrete periods of intense anxiety mounting Physiological arousal fear stomach problems and discomfort that are associated with a variety of Blunted affect is the scientific term describing a lack of Emotional reactivity on the part of an individual Mania (from Greek μανία and that from μαίνομαι - mainomai, "to rage to be furious" is a severe medical condition Psychosis (from the Greek ψυχή "psyche" for mind or soul and -οσις "-osis" for abnormal condition with adjective psychotic

30 to 50% of stroke survivors suffer post stroke depression, which is characterized by lethargy, irritability, sleep disturbances, lowered self esteem, and withdrawal. A sleep disorder (somnipathy is a medical disorder of the Sleep patterns of a person or animal In Psychology, self-esteem reflects a Person 's overall evaluation or appraisal of her or his own worth ^[77] Depression can reduce motivation and worsen outcome, but can be treated with antidepressants. Major depressive disorder, also known as major depression, unipolar depression, unipolar disorder, clinical depression, or simply depression An antidepressant is a Psychiatric medication used for alleviating major depression or Dysthymia ('milder' depression

Emotional lability, another consequence of stroke, causes the patient to switch quickly between emotional highs and lows and to express emotions inappropriately, for instance with an excess of laughing or crying with little or no provocation. Labile affect or pseudobulbar affect refers to the pathological expression of Laughter, Crying or smiling. While these expressions of emotion usually correspond to the patient's actual emotions, a more severe form of emotional lability causes patients to laugh and cry pathologically, without regard to context or emotion. ^[75] Some patients show the opposite of what they feel, for example crying when they are happy. ^[78] Emotional lability occurs in about 20% of stroke patients.

Cognitive deficits resulting from stroke include perceptual disorders, speech problems, dementia, and problems with attention and memory. Dysphasia should not be confused with the similarly pronounced Dysphagia, which is a difficulty swallowing Dementia (from Latin de- "apart away" + Mens ( genitive mentis) "mind" is the progressive decline A stroke sufferer may be unaware of his or her own disabilities, a condition called anosognosia. In a condition called hemispatial neglect, a patient is unable to attend to anything on the side of space opposite to the damaged hemisphere. Hemispatial neglect, also called hemiagnosia, hemineglect, unilateral neglect, spatial neglect or neglect syndrome is a Neurological

Up to 10% of all stroke patients develop seizures, most commonly in the week subsequent to the event; the severity of the stroke increases the likelihood of a seizure. An epileptic seizure is caused by excessive and/or hypersynchronous electrical Neuronal activity and is usually self-limiting ^[79][80]

Epidemiology

Stroke could soon be the most common cause of death worldwide. ^[81] Stroke is the third leading cause of death in the Western world, after heart disease and cancer,^[2] and causes 10% of deaths worldwide. The term Western world, the West or the Occident ( Latin: occidens -sunset -west as distinct from the Orient) can have multiple meanings ^[82]

The incidence of stroke increases exponentially from 30 years of age, and etiology varies by age. Incidence is a measure of the risk of developing some new condition within a specified period of time Exponential growth (including Exponential decay) occurs when the growth rate of a mathematical function is proportional to the function's current value Etiology (alternatively aetiology, aitiology) is the study of causation. ^[83] Advanced age is one of the most significant stroke risk factors. 95% of strokes occur in people age 45 and older, and two-thirds of strokes occur in those over the age of 65. ^[77][8] A person's risk of dying if he or she does have a stroke also increases with age. However, stroke can occur at any age, including in fetuses.

Family members may have a genetic tendency for stroke or share a lifestyle that contributes to stroke. Higher levels of Von Willebrand factor are more common amongst people who have had ischemic stroke for the first time. Von Willebrand factor (vWF is a Blood Glycoprotein involved in Hemostasis. ^[84] The results of this study found that the only significant genetic factor was the person's blood type. A blood type (also called a blood group) is a classification of Blood based on the presence or absence of inherited Antigenic substances on the Having had a stroke in the past greatly increases one's risk of future strokes.

Men are 1. 25 times more likely to suffer strokes than women,^[8] yet 60% of deaths from stroke occur in women. ^[78] Since women live longer, they are older on average when they have their strokes and thus more often killed (NIMH 2002). ^[8] Some risk factors for stroke apply only to women. Primary among these are pregnancy, childbirth, menopause and the treatment thereof (HRT). Hormone replacement therapy may refer to Hormone replacement therapy (menopause Hormone replacement therapy (female-to-male

History

Hippocrates first described the sudden paralysis that is often associated with stroke.

Hippocrates (460 to 370 BC) was first to describe the phenomenon of sudden paralysis. Hippocrates of Cos II or Hippokrates of Kos ( ca. 460 BC – ca Events By place Greece Cleomenes II succeeds his brother Agesipolis II as Agiad king of Sparta. Apoplexy, from the Greek word meaning "struck down with violence,” first appeared in Hippocratic writings to describe this phenomenon. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly ^[85][86]

The word stroke was used as a synonym for apoplectic seizure as early as 1599,^[87] and is a fairly literal translation of the Greek term.

In 1658, in his Apoplexia, Johann Jacob Wepfer (1620–1695) identified the cause of hemorrhagic stroke when he suggested that people who had died of apoplexy had bleeding in their brains. Johann Jakob Wepfer ( December 23 1620 - January 26 1695) was a Swiss Pathologist and Pharmacologist who was a native of ^[85][8] Wepfer also identified the main arteries supplying the brain, the vertebral and carotid arteries, and identified the cause of ischemic stroke when he suggested that apoplexy might be caused by a blockage to those vessels. ^[8]

References

Further reading

• J. P. Mohr, Dennis Choi, James Grotta, Philip Wolf (2004). Stroke: Pathophysiology, Diagnosis, and Management. New York: Churchill Livingstone. ISBN 0-443-06600-0.  

External links

Detailed information

• The original text for this article was taken from the National Institute of Neurological Disorders and Stroke public domain resource at this page
• Stroke: Hope Through Research (National Institute of Neurological Disorders and Stroke)
• Know Stroke: Know The Signs. Act in Time (National Institute of Neurological Disorders and Stroke)
• StrokEngine (McGill University, Montreal, Quebec, Canada) Focuses on stroke rehabilitation and interventions
• Cerebrovascular disease and risk of stroke
• What Happens During a Stroke. The National Institute of Neurological Disorders and Stroke is a part of the U The public domain is a range of abstract materials &ndash commonly referred to as Intellectual property &ndash which are not owned or controlled by anyone Montreal, or Montréal in French ( pronounced in French, in English) is the largest city in the Canadian province of Quebec NLM. Retrieved on 2007-04-15. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1450 - Battle of Formigny: Toward the end of the Hundred Years' War, the French attack and nearly annihilate English video
• "Heart Attack, Stroke and Cardiac Arrest Warning Signs," from the American Heart Association
• StrokeMD.net
• Study of Outcome of Childhood Stroke UK
• Stroke Treatment

National organizations

• National Institute of Neurological Disorders and Stroke - National Institutes of Health
• American Stroke Association
• National Stroke Association
• Canadian Stroke Network
• Registry of the Canadian Stroke Network
• Heart and Stroke Foundation of Canada
• The Stroke Association UK
• National Stroke Association of Malaysia
• Stroke Alliance For Europe (SAFE)