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For other uses, see Stroke (disambiguation). Stroke_sentence_0


Other namesStroke_header_cell_0_1_0 Cerebrovascular accident (CVA), cerebrovascular insult (CVI), brain attackStroke_cell_0_1_1
SpecialtyStroke_header_cell_0_2_0 Neurology, stroke medicineStroke_cell_0_2_1
SymptomsStroke_header_cell_0_3_0 Inability to move or feel on one side of the body, problems understanding or speaking, dizziness, loss of vision to one sideStroke_cell_0_3_1
ComplicationsStroke_header_cell_0_4_0 Persistent vegetative stateStroke_cell_0_4_1
CausesStroke_header_cell_0_5_0 Ischemic (blockage) and hemorrhagic (bleeding)Stroke_cell_0_5_1
Risk factorsStroke_header_cell_0_6_0 High blood pressure, tobacco smoking, obesity, high blood cholesterol, diabetes mellitus, previous TIA, end-stage kidney disease, atrial fibrillationStroke_cell_0_6_1
Diagnostic methodStroke_header_cell_0_7_0 Based on symptoms with medical imaging typically used to rule out bleedingStroke_cell_0_7_1
Differential diagnosisStroke_header_cell_0_8_0 Low blood sugarStroke_cell_0_8_1
TreatmentStroke_header_cell_0_9_0 Based on the typeStroke_cell_0_9_1
PrognosisStroke_header_cell_0_10_0 Average life expectancy 1 yearStroke_cell_0_10_1
FrequencyStroke_header_cell_0_11_0 42.4 million (2015)Stroke_cell_0_11_1
DeathsStroke_header_cell_0_12_0 6.3 million (2015)Stroke_cell_0_12_1

A stroke is a medical condition in which poor blood flow to the brain causes cell death. Stroke_sentence_1

There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Stroke_sentence_2

Both cause parts of the brain to stop functioning properly. Stroke_sentence_3

Signs and symptoms of a stroke may include an inability to move or feel on one side of the body, problems understanding or speaking, dizziness, or loss of vision to one side. Stroke_sentence_4

Signs and symptoms often appear soon after the stroke has occurred. Stroke_sentence_5

If symptoms last less than one or two hours, the stroke is a transient ischemic attack (TIA), also called a mini-stroke. Stroke_sentence_6

A hemorrhagic stroke may also be associated with a severe headache. Stroke_sentence_7

The symptoms of a stroke can be permanent. Stroke_sentence_8

Long-term complications may include pneumonia and loss of bladder control. Stroke_sentence_9

The main risk factor for stroke is high blood pressure. Stroke_sentence_10

Other risk factors include tobacco smoking, obesity, high blood cholesterol, diabetes mellitus, a previous TIA, end-stage kidney disease, and atrial fibrillation. Stroke_sentence_11

An ischemic stroke is typically caused by blockage of a blood vessel, though there are also less common causes. Stroke_sentence_12

A hemorrhagic stroke is caused by either bleeding directly into the brain or into the space between the brain's membranes. Stroke_sentence_13

Bleeding may occur due to a ruptured brain aneurysm. Stroke_sentence_14

Diagnosis is typically based on a physical exam and supported by medical imaging such as a CT scan or MRI scan. Stroke_sentence_15

A CT scan can rule out bleeding, but may not necessarily rule out ischemia, which early on typically does not show up on a CT scan. Stroke_sentence_16

Other tests such as an electrocardiogram (ECG) and blood tests are done to determine risk factors and rule out other possible causes. Stroke_sentence_17

Low blood sugar may cause similar symptoms. Stroke_sentence_18

Prevention includes decreasing risk factors, surgery to open up the arteries to the brain in those with problematic carotid narrowing, and warfarin in people with atrial fibrillation. Stroke_sentence_19

Aspirin or statins may be recommended by physicians for prevention. Stroke_sentence_20

A stroke or TIA often requires emergency care. Stroke_sentence_21

An ischemic stroke, if detected within three to four and half hours, may be treatable with a medication that can break down the clot. Stroke_sentence_22

Some hemorrhagic strokes benefit from surgery. Stroke_sentence_23

Treatment to attempt recovery of lost function is called stroke rehabilitation, and ideally takes place in a stroke unit; however, these are not available in much of the world. Stroke_sentence_24

In 2013, approximately 6.9 million people had an ischemic stroke and 3.4 million people had a hemorrhagic stroke. Stroke_sentence_25

In 2015, there were about 42.4 million people who had previously had a stroke and were still alive. Stroke_sentence_26

Between 1990 and 2010 the number of strokes which occurred each year decreased by approximately 10% in the developed world and increased by 10% in the developing world. Stroke_sentence_27

In 2015, stroke was the second most frequent cause of death after coronary artery disease, accounting for 6.3 million deaths (11% of the total). Stroke_sentence_28

About 3.0 million deaths resulted from ischemic stroke while 3.3 million deaths resulted from hemorrhagic stroke. Stroke_sentence_29

About half of people who have had a stroke live less than one year. Stroke_sentence_30

Overall, two thirds of strokes occurred in those over 65 years old. Stroke_sentence_31

Classification Stroke_section_0

Strokes can be classified into two major categories: ischemic and hemorrhagic. Stroke_sentence_32

Ischemic strokes are caused by interruption of the blood supply to the brain, while hemorrhagic strokes result from the rupture of a blood vessel or an abnormal vascular structure. Stroke_sentence_33

About 87% of strokes are ischemic, the rest being hemorrhagic. Stroke_sentence_34

Bleeding can develop inside areas of ischemia, a condition known as "hemorrhagic transformation." Stroke_sentence_35

It is unknown how many hemorrhagic strokes actually start as ischemic strokes. Stroke_sentence_36

Definition Stroke_section_1

In the 1970s the World Health Organization defined stroke as a "neurological deficit of cerebrovascular cause that persists beyond 24 hours or is interrupted by death within 24 hours", although the word "stroke" is centuries old. Stroke_sentence_37

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. Stroke_sentence_38

The 24-hour limit divides stroke from transient ischemic attack, which is a related syndrome of stroke symptoms that resolve completely within 24 hours. Stroke_sentence_39

With the availability of treatments that can reduce stroke severity when given early, many now prefer alternative terminology, such as brain attack and acute ischemic cerebrovascular syndrome (modeled after heart attack and acute coronary syndrome, respectively), to reflect the urgency of stroke symptoms and the need to act swiftly. Stroke_sentence_40

Ischemic Stroke_section_2

Main articles: Cerebral infarction and Brain ischemia Stroke_sentence_41

In an ischemic stroke, blood supply to part of the brain is decreased, leading to dysfunction of the brain tissue in that area. Stroke_sentence_42

There are four reasons why this might happen: Stroke_sentence_43


  1. Thrombosis (obstruction of a blood vessel by a blood clot forming locally)Stroke_item_0_0
  2. Embolism (obstruction due to an embolus from elsewhere in the body),Stroke_item_0_1
  3. Systemic hypoperfusion (general decrease in blood supply, e.g., in shock)Stroke_item_0_2
  4. Cerebral venous sinus thrombosis.Stroke_item_0_3

A stroke without an obvious explanation is termed cryptogenic (of unknown origin); this constitutes 30–40% of all ischemic strokes. Stroke_sentence_44

There are various classification systems for acute ischemic stroke. Stroke_sentence_45

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 (TACI), partial anterior circulation infarct (PACI), lacunar infarct (LACI) or posterior circulation infarct (POCI). Stroke_sentence_46

These four entities predict the extent of the stroke, the area of the brain that is affected, the underlying cause, and the prognosis. Stroke_sentence_47

The TOAST (Trial of Org 10172 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 of a large artery, (2) an embolism originating in the heart, (3) complete blockage of a small blood vessel, (4) other determined cause, (5) undetermined cause (two possible causes, no cause identified, or incomplete investigation). Stroke_sentence_48

Users of stimulants such as cocaine and methamphetamine are at a high risk for ischemic strokes. Stroke_sentence_49

Hemorrhagic Stroke_section_3

Main articles: Intracerebral hemorrhage and Subarachnoid hemorrhage Stroke_sentence_50

There are two main types of hemorrhagic stroke: Stroke_sentence_51


The above two main types of hemorrhagic stroke are also two different forms of intracranial hemorrhage, which is the accumulation of blood anywhere within the cranial vault; but the other forms of intracranial hemorrhage, such as epidural hematoma (bleeding between the skull and the dura mater, which is the thick outermost layer of the meninges that surround the brain) and subdural hematoma (bleeding in the subdural space), are not considered "hemorrhagic strokes". Stroke_sentence_52

Hemorrhagic strokes may occur on the background of alterations to the blood vessels in the brain, such as cerebral amyloid angiopathy, cerebral arteriovenous malformation and an intracranial aneurysm, which can cause intraparenchymal or subarachnoid hemorrhage. Stroke_sentence_53

In addition to neurological impairment, hemorrhagic strokes usually cause specific symptoms (for instance, subarachnoid hemorrhage classically causes a severe headache known as a thunderclap headache) or reveal evidence of a previous head injury. Stroke_sentence_54

Signs and symptoms Stroke_section_4

Stroke symptoms typically start suddenly, over seconds to minutes, and in most cases do not progress further. Stroke_sentence_55

The symptoms depend on the area of the brain affected. Stroke_sentence_56

The more extensive the area of the brain affected, the more functions that are likely to be lost. Stroke_sentence_57

Some forms of stroke can cause additional symptoms. Stroke_sentence_58

For example, in intracranial hemorrhage, the affected area may compress other structures. Stroke_sentence_59

Most forms of stroke are not associated with a headache, apart from subarachnoid hemorrhage and cerebral venous thrombosis and occasionally intracerebral hemorrhage. Stroke_sentence_60

Early recognition Stroke_section_5

Various systems have been proposed to increase recognition of stroke. Stroke_sentence_61

Different findings are able to predict the presence or absence of stroke to different degrees. Stroke_sentence_62

Sudden-onset face weakness, arm drift (i.e., if a person, when asked to raise both arms, involuntarily lets one arm drift downward) and abnormal speech are the findings most likely to lead to the correct identification of a case of stroke, increasing the likelihood by 5.5 when at least one of these is present. Stroke_sentence_63

Similarly, when all three of these are absent, the likelihood of stroke is decreased (– likelihood ratio of 0.39). Stroke_sentence_64

While these findings are not perfect for diagnosing stroke, the fact that they can be evaluated relatively rapidly and easily make them very valuable in the acute setting. Stroke_sentence_65

A mnemonic to remember the warning signs of stroke is FAST (facial droop, arm weakness, speech difficulty, and time to call emergency services), as advocated by the Department of Health (United Kingdom) and the Stroke Association, the American Stroke Association, the National Stroke Association (US), the Los Angeles Prehospital Stroke Screen (LAPSS) and the Cincinnati Prehospital Stroke Scale (CPSS). Stroke_sentence_66

Use of these scales is recommended by professional guidelines. Stroke_sentence_67

FAST is less reliable in the recognition of posterior circulation strokes. Stroke_sentence_68

For people referred to the emergency room, early recognition of stroke is deemed important as this can expedite diagnostic tests and treatments. Stroke_sentence_69

A scoring system called ROSIER (recognition of stroke in the emergency room) is recommended for this purpose; it is based on features from the medical history and physical examination. Stroke_sentence_70

Subtypes Stroke_section_6

If the area of the brain affected includes one of the three prominent central nervous system pathways—the spinothalamic tract, corticospinal tract, and the dorsal column–medial lemniscus pathway, symptoms may include: Stroke_sentence_71


In most cases, the symptoms affect only one side of the body (unilateral). Stroke_sentence_72

Depending on the part of the brain affected, the defect in the brain is usually on the opposite side of the body. Stroke_sentence_73

However, since these pathways also travel in the spinal cord and any lesion there can also produce these symptoms, the presence of any one of these symptoms does not necessarily indicate a stroke. Stroke_sentence_74

In addition to the above CNS pathways, the brainstem gives rise to most of the twelve cranial nerves. Stroke_sentence_75

A brainstem stroke affecting the brainstem and brain, therefore, can produce symptoms relating to deficits in these cranial nerves: Stroke_sentence_76


  • altered smell, taste, hearing, or vision (total or partial)Stroke_item_3_10
  • drooping of eyelid (ptosis) and weakness of ocular musclesStroke_item_3_11
  • decreased reflexes: gag, swallow, pupil reactivity to lightStroke_item_3_12
  • decreased sensation and muscle weakness of the faceStroke_item_3_13
  • balance problems and nystagmusStroke_item_3_14
  • altered breathing and heart rateStroke_item_3_15
  • weakness in sternocleidomastoid muscle with inability to turn head to one sideStroke_item_3_16
  • weakness in tongue (inability to stick out the tongue or move it from side to side)Stroke_item_3_17

If the cerebral cortex is involved, the CNS pathways can again be affected, but also can produce the following symptoms: Stroke_sentence_77


If the cerebellum is involved, ataxia might be present and this includes: Stroke_sentence_78


Associated symptoms Stroke_section_7

Loss of consciousness, headache, and vomiting usually occur more often in hemorrhagic stroke than in thrombosis because of the increased intracranial pressure from the leaking blood compressing the brain. Stroke_sentence_79

If symptoms are maximal at onset, the cause is more likely to be a subarachnoid hemorrhage or an embolic stroke. Stroke_sentence_80

Causes Stroke_section_8

Thrombotic stroke Stroke_section_9

In thrombotic stroke, a thrombus (blood clot) usually forms around atherosclerotic plaques. Stroke_sentence_81

Since blockage of the artery is gradual, onset of symptomatic thrombotic strokes is slower than that of a hemorrhagic stroke. Stroke_sentence_82

A thrombus itself (even if it does not completely block the blood vessel) can lead to an embolic stroke (see below) if the thrombus breaks off and travels in the bloodstream, at which point it is called an embolus. Stroke_sentence_83

Two types of thrombosis can cause stroke: Stroke_sentence_84


Sickle-cell anemia, which can cause blood cells to clump up and block blood vessels, can also lead to stroke. Stroke_sentence_85

A stroke is the second leading cause of death in people under 20 with sickle-cell anemia. Stroke_sentence_86

Air pollution may also increase stroke risk. Stroke_sentence_87

Embolic stroke Stroke_section_10

An embolic stroke refers to an arterial embolism (a blockage of an artery) by an embolus, a traveling particle or debris in the arterial bloodstream originating from elsewhere. Stroke_sentence_88

An embolus is most frequently a thrombus, but it can also be a number of other substances including fat (e.g., from bone marrow in a broken bone), air, cancer cells or clumps of bacteria (usually from infectious endocarditis). Stroke_sentence_89

Because an embolus arises from elsewhere, local therapy solves the problem only temporarily. Stroke_sentence_90

Thus, the source of the embolus must be identified. Stroke_sentence_91

Because the embolic blockage is sudden in onset, symptoms usually are maximal at the start. Stroke_sentence_92

Also, symptoms may be transient as the embolus is partially resorbed and moves to a different location or dissipates altogether. Stroke_sentence_93

Emboli most commonly arise from the heart (especially in atrial fibrillation) but may originate from elsewhere in the arterial tree. Stroke_sentence_94

In paradoxical embolism, a deep vein thrombosis embolizes through an atrial or ventricular septal defect in the heart into the brain. Stroke_sentence_95

Causes of stroke related to the heart can be distinguished between high and low-risk: Stroke_sentence_96


Among those who have a complete blockage of one of the carotid arteries, the risk of stroke on that side is about one percent per year. Stroke_sentence_97

A special form of embolic stroke is the embolic stroke of undetermined source (ESUS). Stroke_sentence_98

This subset of cryptogenic stroke is defined as a non-lacunar brain infarct without proximal arterial stenosis or cardioembolic sources. Stroke_sentence_99

About one out of six ischemic strokes could be classified as ESUS. Stroke_sentence_100

Cerebral hypoperfusion Stroke_section_11

Cerebral hypoperfusion is the reduction of blood flow to all parts of the brain. Stroke_sentence_101

The reduction could be to a particular part of the brain depending on the cause. Stroke_sentence_102

It is most commonly due to heart failure from cardiac arrest or arrhythmias, or from reduced cardiac output as a result of myocardial infarction, pulmonary embolism, pericardial effusion, or bleeding. Stroke_sentence_103

Hypoxemia (low blood oxygen content) may precipitate the hypoperfusion. Stroke_sentence_104

Because the reduction in blood flow is global, all parts of the brain may be affected, especially vulnerable "watershed" areas—border zone regions supplied by the major cerebral arteries. Stroke_sentence_105

A watershed stroke refers to the condition when the blood supply to these areas is compromised. Stroke_sentence_106

Blood flow to these areas does not necessarily stop, but instead it may lessen to the point where brain damage can occur. Stroke_sentence_107

Venous thrombosis Stroke_section_12

Cerebral venous sinus thrombosis leads to stroke due to locally increased venous pressure, which exceeds the pressure generated by the arteries. Stroke_sentence_108

Infarcts are more likely to undergo hemorrhagic transformation (leaking of blood into the damaged area) than other types of ischemic stroke. Stroke_sentence_109

Intracerebral hemorrhage Stroke_section_13

It generally occurs in small arteries or arterioles and is commonly due to hypertension, intracranial vascular malformations (including cavernous angiomas or arteriovenous malformations), cerebral amyloid angiopathy, or infarcts into which secondary hemorrhage has occurred. Stroke_sentence_110

Other potential causes are trauma, bleeding disorders, amyloid angiopathy, illicit drug use (e.g., amphetamines or cocaine). Stroke_sentence_111

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. Stroke_sentence_112

A third of intracerebral bleed is into the brain's ventricles. Stroke_sentence_113

ICH has a mortality rate of 44 percent after 30 days, higher than ischemic stroke or subarachnoid hemorrhage (which technically may also be classified as a type of stroke). Stroke_sentence_114

Other Stroke_section_14

Other causes may include spasm of an artery. Stroke_sentence_115

This may occur due to cocaine. Stroke_sentence_116

Silent stroke Stroke_section_15

A silent stroke is a stroke that does not have any outward symptoms, and people are typically unaware they have had a stroke. Stroke_sentence_117

Despite not causing identifiable symptoms, a silent stroke still damages the brain and places the person at increased risk for both transient ischemic attack and major stroke in the future. Stroke_sentence_118

Conversely, those who have had a major stroke are also at risk of having silent strokes. Stroke_sentence_119

In a broad study in 1998, more than 11 million people were estimated to have experienced a stroke in the United States. Stroke_sentence_120

Approximately 770,000 of these strokes were symptomatic and 11 million were first-ever silent MRI infarcts or hemorrhages. Stroke_sentence_121

Silent strokes typically cause lesions which are detected via the use of neuroimaging such as MRI. Stroke_sentence_122

Silent strokes are estimated to occur at five times the rate of symptomatic strokes. Stroke_sentence_123

The risk of silent stroke increases with age, but may also affect younger adults and children, especially those with acute anemia. Stroke_sentence_124

Pathophysiology Stroke_section_16

Ischemic Stroke_section_17

Ischemic stroke occurs because of a loss of blood supply to part of the brain, initiating the ischemic cascade. Stroke_sentence_125

Brain tissue ceases to function if deprived of oxygen for more than 60 to 90 seconds, and after approximately three hours will suffer irreversible injury possibly leading to the death of the tissue, i.e., infarction. Stroke_sentence_126

(This is why fibrinolytics such as alteplase are given only until three hours since the onset of the stroke.) Stroke_sentence_127

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. Stroke_sentence_128

Embolic infarction occurs when emboli formed elsewhere in the circulatory system, typically in the heart as a consequence of atrial fibrillation, or in the carotid arteries, break off, enter the cerebral circulation, then lodge in and block brain blood vessels. Stroke_sentence_129

Since blood vessels in the brain are now blocked, the brain becomes low in energy, and thus it resorts to using anaerobic metabolism within the region of brain tissue affected by ischemia. Stroke_sentence_130

Anaerobic metabolism produces less adenosine triphosphate (ATP) but releases a by-product called lactic acid. Stroke_sentence_131

Lactic acid is an irritant which could potentially destroy cells since it is an acid and disrupts the normal acid-base balance in the brain. Stroke_sentence_132

The ischemia area is referred to as the "ischemic penumbra". Stroke_sentence_133

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. Stroke_sentence_134

This sets off a series of interrelated events that result in cellular injury and death. Stroke_sentence_135

A major cause of neuronal injury is the release of the excitatory neurotransmitter glutamate. Stroke_sentence_136

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. Stroke_sentence_137

However, stroke cuts off the supply of oxygen and glucose which powers the ion pumps maintaining these gradients. Stroke_sentence_138

As a result, the transmembrane ion gradients run down, and glutamate transporters reverse their direction, releasing glutamate into the extracellular space. Stroke_sentence_139

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. Stroke_sentence_140

Calcium influx can also lead to the failure of mitochondria, which can lead further toward energy depletion and may trigger cell death due to programmed cell death. Stroke_sentence_141

Ischemia also induces production of oxygen free radicals and other reactive oxygen species. Stroke_sentence_142

These react with and damage a number of cellular and extracellular elements. Stroke_sentence_143

Damage to the blood vessel lining or endothelium is particularly important. Stroke_sentence_144

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. Stroke_sentence_145

Free radicals also directly initiate elements of the programmed cell death cascade by means of redox signaling. Stroke_sentence_146

These processes are the same for any type of ischemic tissue and are referred to collectively as the ischemic cascade. Stroke_sentence_147

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. Stroke_sentence_148

In addition to damaging 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. Stroke_sentence_149

Other proteases also contribute to this process. Stroke_sentence_150

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. Stroke_sentence_151

Hemorrhagic Stroke_section_18

Hemorrhagic strokes are classified based on their underlying pathology. Stroke_sentence_152

Some causes of hemorrhagic stroke are hypertensive hemorrhage, ruptured aneurysm, ruptured AV fistula, transformation of prior ischemic infarction, and drug-induced bleeding. Stroke_sentence_153

They result in tissue injury by causing compression of tissue from an expanding hematoma or hematomas. Stroke_sentence_154

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. Stroke_sentence_155

Inflammation contributes to the secondary brain injury after hemorrhage. Stroke_sentence_156

Diagnosis Stroke_section_19

Stroke is diagnosed through several techniques: a neurological examination (such as the NIHSS), CT scans (most often without contrast enhancements) or MRI scans, Doppler ultrasound, and arteriography. Stroke_sentence_157

The diagnosis of stroke itself is clinical, with assistance from the imaging techniques. Stroke_sentence_158

Imaging techniques also assist in determining the subtypes and cause of stroke. Stroke_sentence_159

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. Stroke_sentence_160

Physical examination Stroke_section_20

A physical examination, including taking a medical history of the symptoms and a neurological status, helps giving an evaluation of the location and severity of a stroke. Stroke_sentence_161

It can give a standard score on e.g., the NIH stroke scale. Stroke_sentence_162

Imaging Stroke_section_21

For diagnosing ischemic (blockage) stroke in the emergency setting: Stroke_sentence_163


  • CT scans (without contrast enhancements)Stroke_item_8_33


  • sensitivity= 16% (less than 10% within first 3 hours of symptom onset)Stroke_item_9_34
  • specificity= 96%Stroke_item_9_35


  • MRI scanStroke_item_10_36


  • sensitivity= 83%Stroke_item_11_37
  • specificity= 98%Stroke_item_11_38

For diagnosing hemorrhagic stroke in the emergency setting: Stroke_sentence_164


  • CT scans (without contrast enhancements)Stroke_item_12_39


  • sensitivity= 89%Stroke_item_13_40
  • specificity= 100%Stroke_item_13_41


  • MRI scanStroke_item_14_42


  • sensitivity= 81%Stroke_item_15_43
  • specificity= 100%Stroke_item_15_44

For detecting chronic hemorrhages, MRI scan is more sensitive. Stroke_sentence_165

For the assessment of stable stroke, nuclear medicine scans SPECT and PET/CT may be helpful. Stroke_sentence_166

SPECT documents cerebral blood flow and PET with FDG isotope the metabolic activity of the neurons. Stroke_sentence_167

CT scans may not detect an ischemic stroke, especially if it is small, of recent onset, or in the brainstem or cerebellum areas. Stroke_sentence_168

A CT scan is more to rule out certain stroke mimics and detect bleeding. Stroke_sentence_169

Underlying cause Stroke_section_22

When a stroke has been diagnosed, various other studies may be performed to determine the underlying cause. Stroke_sentence_170

With the current treatment and diagnosis options available, it is of particular importance to determine whether there is a peripheral source of emboli. Stroke_sentence_171

Test selection may vary since the cause of stroke varies with age, comorbidity and the clinical presentation. Stroke_sentence_172

The following are commonly used techniques: Stroke_sentence_173


For hemorrhagic strokes, a CT or MRI scan with intravascular contrast may be able to identify abnormalities in the brain arteries (such as aneurysms) or other sources of bleeding, and structural MRI if this shows no cause. Stroke_sentence_174

If this too does not identify an underlying reason for the bleeding, invasive cerebral angiography could be performed but this requires access to the bloodstream with an intravascular catheter and can cause further strokes as well as complications at the insertion site and this investigation is therefore reserved for specific situations. Stroke_sentence_175

If there are symptoms suggesting that the hemorrhage might have occurred as a result of venous thrombosis, CT or MRI venography can be used to examine the cerebral veins. Stroke_sentence_176

Misdiagnosis Stroke_section_23

Among people with ischemic strokes, misdiagnosis occurs 2 to 26% of the time. Stroke_sentence_177

A "stroke chameleon" (SC) is stroke which is diagnosed as something else. Stroke_sentence_178

People not having a stroke may also be misdiagnosed as a stroke. Stroke_sentence_179

Giving thrombolytics (clot-busting) in such cases causes intracerebral bleeding 1 to 2% of the time, which is less than that of people with strokes. Stroke_sentence_180

This unnecessary treatment adds to health care costs. Stroke_sentence_181

Even so, the AHA/ASA guidelines state that starting intravenous tPA in possible mimics is preferred to delaying treatment for additional testing. Stroke_sentence_182

Women, African-Americans, Hispanic-Americans, Asian and Pacific Islanders are more often misdiagnosed for a condition other than stroke when in fact having a stroke. Stroke_sentence_183

In addition, adults under 44 years-of-age are seven times more likely to have a stroke missed than are adults over 75 years-of-age. Stroke_sentence_184

This is especially the case for younger people with posterior circulation infarcts. Stroke_sentence_185

Some medical centers have used hyperacute MRI in experimental studies for persons initially thought to have a low likelihood of stroke. Stroke_sentence_186

And in some of these persons, strokes have been found which were then treated with thrombolytic medication. Stroke_sentence_187

Prevention Stroke_section_24

Given the disease burden of strokes, prevention is an important public health concern. Stroke_sentence_188

Primary prevention is less effective than secondary prevention (as judged by the number needed to treat to prevent one stroke per year). Stroke_sentence_189

Recent guidelines detail the evidence for primary prevention in stroke. Stroke_sentence_190

In those who are otherwise healthy, aspirin does not appear beneficial and thus is not recommended. Stroke_sentence_191

In people who have had a myocardial infarction or those with a high cardiovascular risk, it provides some protection against a first stroke. Stroke_sentence_192

In those who have previously had a stroke, treatment with medications such as aspirin, clopidogrel, and dipyridamole may be beneficial. Stroke_sentence_193

The U.S. Stroke_sentence_194 Preventive Services Task Force (USPSTF) recommends against screening for carotid artery stenosis in those without symptoms. Stroke_sentence_195

Risk factors Stroke_section_25

The most important modifiable risk factors for stroke are high blood pressure and atrial fibrillation although the size of the effect is small with 833 people have to be treated for 1 year to prevent one stroke. Stroke_sentence_196

Other modifiable risk factors include high blood cholesterol levels, diabetes mellitus, end-stage kidney disease, cigarette smoking (active and passive), heavy alcohol use, drug use, lack of physical activity, obesity, processed red meat consumption, and unhealthy diet. Stroke_sentence_197

Smoking just one cigarette per day increases the risk more than 30%. Stroke_sentence_198

Alcohol use could predispose to ischemic stroke, as well as intracerebral and subarachnoid hemorrhage via multiple mechanisms (for example, via hypertension, atrial fibrillation, rebound thrombocytosis and platelet aggregation and clotting disturbances). Stroke_sentence_199

Drugs, most commonly amphetamines and cocaine, can induce stroke through damage to the blood vessels in the brain and acute hypertension. Stroke_sentence_200

Migraine with aura doubles a person's risk for ischemic stroke. Stroke_sentence_201

Untreated, celiac disease regardless of the presence of symptoms can be an underlying cause of stroke, both in children and adults. Stroke_sentence_202

High levels of physical activity reduce the risk of stroke by about 26%. Stroke_sentence_203

There is a lack of high quality studies looking at promotional efforts to improve lifestyle factors. Stroke_sentence_204

Nonetheless, given the large body of circumstantial evidence, best medical management for stroke includes advice on diet, exercise, smoking and alcohol use. Stroke_sentence_205

Medication is the most common method of stroke prevention; carotid endarterectomy can be a useful surgical method of preventing stroke. Stroke_sentence_206

Blood pressure Stroke_section_26

High blood pressure accounts for 35–50% of stroke risk. Stroke_sentence_207

Blood pressure reduction of 10 mmHg systolic or 5 mmHg diastolic reduces the risk of stroke by ~40%. Stroke_sentence_208

Lowering blood pressure has been conclusively shown to prevent both ischemic and hemorrhagic strokes. Stroke_sentence_209

It is equally important in secondary prevention. Stroke_sentence_210

Even people older than 80 years and those with isolated systolic hypertension benefit from antihypertensive therapy. Stroke_sentence_211

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 and cost should be considered. Stroke_sentence_212

The routine use of beta-blockers following a stroke or TIA has not been shown to result in benefits. Stroke_sentence_213

Blood lipids Stroke_section_27

High cholesterol levels have been inconsistently associated with (ischemic) stroke. Stroke_sentence_214

Statins have been shown to reduce the risk of stroke by about 15%. Stroke_sentence_215

Since earlier meta-analyses of other lipid-lowering drugs did not show a decreased risk, statins might exert their effect through mechanisms other than their lipid-lowering effects. Stroke_sentence_216

Diabetes mellitus Stroke_section_28

Diabetes mellitus increases the risk of stroke by 2 to 3 times. Stroke_sentence_217

While intensive blood sugar control has been shown to reduce small blood vessel complications such as kidney damage and damage to the retina of the eye it has not been shown to reduce large blood vessel complications such as stroke. Stroke_sentence_218

Anticoagulation drugs Stroke_section_29

Oral anticoagulants such as warfarin have been the mainstay of stroke prevention for over 50 years. Stroke_sentence_219

However, several studies have shown that aspirin and other antiplatelets are highly effective in secondary prevention after a stroke or transient ischemic attack. Stroke_sentence_220

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. Stroke_sentence_221

Thienopyridines (clopidogrel, ticlopidine) might be slightly more effective than aspirin and have a decreased risk of gastrointestinal bleeding, but are more expensive. Stroke_sentence_222

Both aspirin and clopidogrel may be useful in the first few weeks after a minor stroke or high risk TIA. Stroke_sentence_223

Clopidogrel has less side effects than ticlopidine. Stroke_sentence_224

Dipyridamole can be added to aspirin therapy to provide a small additional benefit, even though headache is a common side effect. Stroke_sentence_225

Low-dose aspirin is also effective for stroke prevention after having a myocardial infarction. Stroke_sentence_226

Those with atrial fibrillation have a 5% a year risk of stroke, and this risk is higher in those with valvular atrial fibrillation. Stroke_sentence_227

Depending on the stroke risk, anticoagulation with medications such as warfarin or aspirin is useful for prevention. Stroke_sentence_228

Except in people with atrial fibrillation, oral anticoagulants are not advised for stroke prevention—any benefit is offset by bleeding risk. Stroke_sentence_229

In primary prevention, however, antiplatelet drugs did not reduce the risk of ischemic stroke but increased the risk of major bleeding. Stroke_sentence_230

Further studies are needed to investigate a possible protective effect of aspirin against ischemic stroke in women. Stroke_sentence_231

Surgery Stroke_section_30

Carotid endarterectomy or carotid angioplasty can be used to remove atherosclerotic narrowing of the carotid artery. Stroke_sentence_232

There is evidence supporting this procedure in selected cases. Stroke_sentence_233

Endarterectomy for a significant stenosis has been shown to be useful in preventing further strokes in those who have already had one. Stroke_sentence_234

Carotid artery stenting has not been shown to be equally useful. Stroke_sentence_235

People are selected for surgery based on age, gender, degree of stenosis, time since symptoms and the person's preferences. Stroke_sentence_236

Surgery is most efficient when not delayed too long—the risk of recurrent stroke in a person who has a 50% or greater stenosis is up to 20% after 5 years, but endarterectomy reduces this risk to around 5%. Stroke_sentence_237

The number of procedures needed to cure one person was 5 for early surgery (within two weeks after the initial stroke), but 125 if delayed longer than 12 weeks. Stroke_sentence_238

Screening for carotid artery narrowing has not been shown to be a useful test in the general population. Stroke_sentence_239

Studies of surgical intervention for carotid artery stenosis without symptoms have shown only a small decrease in the risk of stroke. Stroke_sentence_240

To be beneficial, the complication rate of the surgery should be kept below 4%. Stroke_sentence_241

Even then, for 100 surgeries, 5 people 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. Stroke_sentence_242

Diet Stroke_section_31

Nutrition, specifically the Mediterranean-style diet, has the potential for decreasing the risk of having a stroke by more than half. Stroke_sentence_243

It does not appear that lowering levels of homocysteine with folic acid affects the risk of stroke. Stroke_sentence_244

Women Stroke_section_32

A number of specific recommendations have been made for women including taking aspirin after the 11th week of pregnancy if there is a history of previous chronic high blood pressure and taking blood pressure medications during pregnancy if the blood pressure is greater than 150 mmHg systolic or greater than 100 mmHg diastolic. Stroke_sentence_245

In those who have previously had preeclampsia other risk factors should be treated more aggressively. Stroke_sentence_246

Previous stroke or TIA Stroke_section_33

Keeping blood pressure below 140/90 mmHg is recommended. Stroke_sentence_247

Anticoagulation can prevent recurrent ischemic strokes. Stroke_sentence_248

Among people with nonvalvular atrial fibrillation, anticoagulation can reduce stroke by 60% while antiplatelet agents can reduce stroke by 20%. Stroke_sentence_249

However, a recent meta-analysis suggests harm from anticoagulation started early after an embolic stroke. Stroke_sentence_250

Stroke prevention treatment for atrial fibrillation is determined according to the CHA2DS2–VASc score. Stroke_sentence_251

The most widely used anticoagulant to prevent thromboembolic stroke in people with nonvalvular atrial fibrillation is the oral agent warfarin while a number of newer agents including dabigatran are alternatives which do not require prothrombin time monitoring. Stroke_sentence_252

Anticoagulants, when used following stroke, should not be stopped for dental procedures. Stroke_sentence_253

If studies show carotid artery stenosis, and the person has a degree of residual function on the affected side, carotid endarterectomy (surgical removal of the stenosis) may decrease the risk of recurrence if performed rapidly after stroke. Stroke_sentence_254

Management Stroke_section_34

Ischemic stroke Stroke_section_35

Aspirin reduces the overall risk of recurrence by 13% with greater benefit early on. Stroke_sentence_255

Definitive therapy within the first few hours is aimed at removing the blockage by breaking the clot down (thrombolysis), or by removing it mechanically (thrombectomy). Stroke_sentence_256

The philosophical premise underlying the importance of rapid stroke intervention was summed up as Time is Brain! Stroke_sentence_257

in the early 1990s. Stroke_sentence_258

Years later, that same idea, that rapid cerebral blood flow restoration results in fewer brain cells dying, has been proved and quantified. Stroke_sentence_259

Tight blood sugar control in the first few hours does not improve outcomes and may cause harm. Stroke_sentence_260

High blood pressure is also not typically lowered as this has not been found to be helpful. Stroke_sentence_261

Cerebrolysin, a mix of pig brain tissue used to treat acute ischemic stroke in many Asian and European countries, does not improve outcomes and may increase the risk of severe adverse events. Stroke_sentence_262

Thrombolysis Stroke_section_36

Thrombolysis, such as with recombinant tissue plasminogen activator (rtPA), in acute ischemic stroke, when given within three hours of symptom onset, results in an overall benefit of 10% with respect to living without disability. Stroke_sentence_263

It does not, however, improve chances of survival. Stroke_sentence_264

Benefit is greater the earlier it is used. Stroke_sentence_265

Between three and four and a half hours the effects are less clear. Stroke_sentence_266

The AHA/ASA recommend it for certain people in this time frame. Stroke_sentence_267

A 2014 review found a 5% increase in the number of people living without disability at three to six months; however, there was a 2% increased risk of death in the short term. Stroke_sentence_268

After four and a half hours thrombolysis worsens outcomes. Stroke_sentence_269

These benefits or lack of benefits occurred regardless of the age of the person treated. Stroke_sentence_270

There is no reliable way to determine who will have an intracranial bleed post-treatment versus who will not. Stroke_sentence_271

In those with findings of savable tissue on medical imaging between 4.5 hours and 9 hours or who wake up with a stroke, alteplase results in some benefit. Stroke_sentence_272

Its use is endorsed by the American Heart Association, the American College of Emergency Physicians 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 no other contraindications (such as abnormal lab values, high blood pressure, or recent surgery). Stroke_sentence_273

This position for tPA is based upon the findings of two studies by one group of investigators which showed that tPA improves the chances for a good neurological outcome. Stroke_sentence_274

When administered within the first three hours thrombolysis improves functional outcome without affecting mortality. Stroke_sentence_275

6.4% of people with large strokes developed substantial brain bleeding as a complication from being given tPA thus part of the reason for increased short term mortality. Stroke_sentence_276

The American Academy of Emergency Medicine had previously stated that objective evidence regarding the applicability of tPA for acute ischemic stroke was insufficient. Stroke_sentence_277

In 2013 the American College of Emergency Medicine refuted this position, acknowledging the body of evidence for the use of tPA in ischemic stroke; but debate continues. Stroke_sentence_278

Intra-arterial fibrinolysis, where a catheter is passed up an artery into the brain and the medication is injected at the site of thrombosis, has been found to improve outcomes in people with acute ischemic stroke. Stroke_sentence_279

Endovascular treatment Stroke_section_37

Mechanical removal of the blood clot causing the ischemic stroke, called mechanical thrombectomy, is a potential treatment for occlusion of a large artery, such as the middle cerebral artery. Stroke_sentence_280

In 2015, one review demonstrated the safety and efficacy of this procedure if performed within 12 hours of the onset of symptoms. Stroke_sentence_281

It did not change the risk of death, but reduced disability compared to the use of intravenous thrombolysis which is generally used in people evaluated for mechanical thrombectomy. Stroke_sentence_282

Certain cases may benefit from thrombectomy up to 24 hours after the onset of symptoms. Stroke_sentence_283

Craniectomy Stroke_section_38

Strokes affecting large portions of the brain can cause significant brain swelling with secondary brain injury in surrounding tissue. Stroke_sentence_284

This phenomenon is mainly encountered in strokes affecting brain tissue dependent upon the middle cerebral artery for blood supply and is also called "malignant cerebral infarction" because it carries a dismal prognosis. Stroke_sentence_285

Relief of the pressure may be attempted with medication, but some require hemicraniectomy, the temporary surgical removal of the skull on one side of the head. Stroke_sentence_286

This decreases the risk of death, although some people – who would otherwise have died – survive with disability. Stroke_sentence_287

Hemorrhagic stroke Stroke_section_39

People with intracerebral hemorrhage require supportive care, including blood pressure control if required. Stroke_sentence_288

People are monitored for changes in the level of consciousness, and their blood sugar and oxygenation are kept at optimum levels. Stroke_sentence_289

Anticoagulants and antithrombotics can make bleeding worse and are generally discontinued (and reversed if possible). Stroke_sentence_290

A proportion may benefit from neurosurgical intervention to remove the blood and treat the underlying cause, but this depends on the location and the size of the hemorrhage as well as patient-related factors, and ongoing research is being conducted into the question as to which people with intracerebral hemorrhage may benefit. Stroke_sentence_291

In subarachnoid hemorrhage, early treatment for underlying cerebral aneurysms may reduce the risk of further hemorrhages. Stroke_sentence_292

Depending on the site of the aneurysm this may be by surgery that involves opening the skull or endovascularly (through the blood vessels). Stroke_sentence_293

Stroke unit Stroke_section_40

Ideally, people who have had a stroke are admitted to a "stroke unit", a ward or dedicated area in a hospital staffed by nurses and therapists with experience in stroke treatment. Stroke_sentence_294

It has been shown that people admitted to a stroke unit have a higher chance of surviving than those admitted elsewhere in hospital, even if they are being cared for by doctors without experience in stroke. Stroke_sentence_295

Nursing care is fundamental in maintaining skin care, feeding, hydration, positioning, and monitoring vital signs such as temperature, pulse, and blood pressure. Stroke_sentence_296

Rehabilitation Stroke_section_41

Stroke rehabilitation is the process by which those 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_sentence_297

It also aims to help the survivor understand and adapt to difficulties, prevent secondary complications, and educate family members to play a supporting role. Stroke_sentence_298

Stroke rehabilitation should begin almost immediately with a multidisciplinary approach. Stroke_sentence_299

The rehabilitation team may involve physicians trained in rehabilitation medicine, neurologists, clinical pharmacists, nursing staff, physiotherapists, occupational therapists, speech-language pathologists, and orthotists. Stroke_sentence_300

Some teams may also include psychologists and social workers, since at least one-third of affected people manifests post stroke depression. Stroke_sentence_301

Validated instruments such as the Barthel scale may be used to assess the likelihood of a person who has had a stroke being able to manage at home with or without support subsequent to discharge from a hospital. Stroke_sentence_302

Stroke rehabilitation should be started as quickly as possible and can last anywhere from a few days to over a year. Stroke_sentence_303

Most return of function is seen in the first few months, and then improvement falls off with the "window" considered officially by U.S. Stroke_sentence_304 state rehabilitation units and others to be closed after six months, with little chance of further improvement. Stroke_sentence_305

However, some people have reported that they continue to improve for years, regaining and strengthening abilities like writing, walking, running, and talking. Stroke_sentence_306

Daily rehabilitation exercises should continue to be part of the daily routine for people who have had a stroke. Stroke_sentence_307

Complete recovery is unusual but not impossible and most people will improve to some extent: proper diet and exercise are known to help the brain to recover. Stroke_sentence_308

Physical and occupational therapy Stroke_section_42

Physical and occupational therapy have overlapping areas of expertise; however, physical therapy focuses on joint range of motion and strength by performing exercises and relearning functional tasks such as bed mobility, transferring, walking and other gross motor functions. Stroke_sentence_309

Physiotherapists can also work with people who have had a stroke to improve awareness and use of the hemiplegic side. Stroke_sentence_310

Rehabilitation involves working on the ability to produce strong movements or the ability to perform tasks using normal patterns. Stroke_sentence_311

Emphasis is often concentrated on functional tasks and people's goals. Stroke_sentence_312

One example physiotherapists employ to promote motor learning involves constraint-induced movement therapy. Stroke_sentence_313

Through continuous practice the person relearns to use and adapt the hemiplegic limb during functional activities to create lasting permanent changes. Stroke_sentence_314

Physical therapy is effective for recovery of function and mobility after stroke. Stroke_sentence_315

Occupational therapy is involved in 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. Stroke_sentence_316

Approaches to helping people with urinary incontinence include physical therapy, cognitive therapy, and specialized interventions with experienced medical professionals, however, it is not clear how effective these approaches are at improving urinary incontinence following a stroke. Stroke_sentence_317

Treatment of spasticity related to stroke often involves early mobilizations, commonly performed by a physiotherapist, combined with elongation of spastic muscles and sustained stretching through various different positions. Stroke_sentence_318

Gaining initial improvement in range of motion is often achieved through rhythmic rotational patterns associated with the affected limb. Stroke_sentence_319

After full range has been achieved by the therapist, the limb should be positioned in the lengthened positions to prevent against further contractures, skin breakdown, and disuse of the limb with the use of splints or other tools to stabilize the joint. Stroke_sentence_320

Cold in the form of ice wraps or ice packs have been proven to briefly reduce spasticity by temporarily dampening neural firing rates. Stroke_sentence_321

Electrical stimulation to the antagonist muscles or vibrations has also been used with some success. Stroke_sentence_322

Physical therapy is sometimes suggested for people who experience sexual dysfunction following a stroke. Stroke_sentence_323

Speech and language therapy Stroke_section_43

Speech and language therapy is appropriate for people with the speech production disorders: dysarthria and apraxia of speech, aphasia, cognitive-communication impairments, and problems with swallowing. Stroke_sentence_324

Speech and language therapy for aphasia following stroke compared to no therapy improves functional communication, reading, writing and expressive language. Stroke_sentence_325

There may be benefit in high intensity and high doses over a longer period, but these higher intensity doses may not be acceptable to everyone. Stroke_sentence_326

People who have had a stroke may have particular problems, such as dysphagia, which can cause swallowed material to pass into the lungs and cause aspiration pneumonia. Stroke_sentence_327

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. Stroke_sentence_328

If swallowing is still deemed unsafe, then a percutaneous endoscopic gastrostomy (PEG) tube is passed and this can remain indefinitely. Stroke_sentence_329

Swallowing therapy has mixed results as of 2018. Stroke_sentence_330

Devices Stroke_section_44

Often, assistive technology such as wheelchairs, walkers and canes may be beneficial. Stroke_sentence_331

Many mobility problems can be improved by the use of ankle foot orthoses. Stroke_sentence_332

Physical fitness Stroke_section_45

A stroke can also reduce people's general fitness. Stroke_sentence_333

Reduced fitness can reduce capacity for rehabilitation as well as general health. Stroke_sentence_334

Physical exercises as part of a rehabilitation program following a stroke appear safe. Stroke_sentence_335

Cardiorespiratory fitness training that involves walking in rehabilitation can improve speed, tolerance and independence during walking, and may improve balance. Stroke_sentence_336

There are inadequate long-term data about the effects of exercise and training on death, dependence and disability after a stroke. Stroke_sentence_337

The future areas of research may concentrate on the optimal exercise prescription and long-term health benefits of exercise. Stroke_sentence_338

The effect of physical training on cognition also may be studied further. Stroke_sentence_339

The ability to walk independently in their community, indoors or outdoors, is important following stroke. Stroke_sentence_340

Although no negative effects have been reported, it is unclear if outcomes can improve with these walking programs when compared to usual treatment. Stroke_sentence_341

Other therapy methods Stroke_section_46

Some current and future therapy methods include the use of virtual reality and video games for rehabilitation. Stroke_sentence_342

These forms of rehabilitation offer potential for motivating people to perform specific therapy tasks that many other forms do not. Stroke_sentence_343

While virtual reality and interactive video gaming are not more effective than conventional therapy for improving upper limb function, when used in conjunction with usual care these approaches may improve upper limb function and ADL function. Stroke_sentence_344

There are inadequate data on the effect of virtual reality and interactive video gaming on gait speed, balance, participation and quality of life. Stroke_sentence_345

Many clinics and hospitals are adopting the use of these off-the-shelf devices for exercise, social interaction, and rehabilitation because they are affordable, accessible and can be used within the clinic and home. Stroke_sentence_346

Mirror therapy is associated with improved motor function of the upper extremity in people who have had a stroke. Stroke_sentence_347

Other non-invasive rehabilitation methods used to augment physical therapy of motor function in people recovering from a stroke include transcranial magnetic stimulation and transcranial direct-current stimulation. Stroke_sentence_348

and robotic therapies. Stroke_sentence_349

Constraint‐induced movement therapy (CIMT), mental practice, mirror therapy, interventions for sensory impairment, virtual reality and a relatively high dose of repetitive task practice may be effective in improving upper limb function. Stroke_sentence_350

However, further primary research, specifically of CIMT, mental practice, mirror therapy and virtual reality is needed. Stroke_sentence_351

Self-management Stroke_section_47

A stroke can affect the ability to live independently and with quality. Stroke_sentence_352

Self-management programs are a special training that educates stroke survivors about stroke and its consequences, helps them acquire skills to cope with their challenges, and helps them set and meet their own goals during their recovery process. Stroke_sentence_353

These programs are tailored to the target audience, and led by someone trained and expert in stroke and its consequences (most commonly professionals, but also stroke survivors and peers). Stroke_sentence_354

A 2016 review reported that these programs improve the quality of life after stroke, without negative effects. Stroke_sentence_355

People with stroke felt more empowered, happy and satisfied with life after participating in this training. Stroke_sentence_356

Prognosis Stroke_section_48

Disability affects 75% of stroke survivors enough to decrease their ability to work. Stroke_sentence_357

Stroke can affect people physically, mentally, emotionally, or a combination of the three. Stroke_sentence_358

The results of stroke vary widely depending on size and location of the lesion. Stroke_sentence_359

Physical effects Stroke_section_49

Some of the physical disabilities that can result from stroke include muscle weakness, numbness, pressure sores, pneumonia, incontinence, apraxia (inability to perform learned movements), difficulties carrying out daily activities, appetite loss, speech loss, vision loss and pain. Stroke_sentence_360

If the stroke is severe enough, or in a certain location such as parts of the brainstem, coma or death can result. Stroke_sentence_361

Up to 10% of people following a stroke develop seizures, most commonly in the week subsequent to the event; the severity of the stroke increases the likelihood of a seizure. Stroke_sentence_362

An estimated 15% of people experience urinary incontinence for more than a year following a stroke. Stroke_sentence_363

50% of people have a decline in sexual function (sexual dysfunction) following a stroke. Stroke_sentence_364

Emotional and mental effects Stroke_section_50

Emotional and mental dysfunctions correspond to areas in the brain that have been damaged. Stroke_sentence_365

Emotional problems following a stroke can be due to direct damage to emotional centers in the brain or from frustration and difficulty adapting to new limitations. Stroke_sentence_366

Post-stroke emotional difficulties include anxiety, panic attacks, flat affect (failure to express emotions), mania, apathy and psychosis. Stroke_sentence_367

Other difficulties may include a decreased ability to communicate emotions through facial expression, body language and voice. Stroke_sentence_368

Disruption in self-identity, relationships with others, and emotional well-being can lead to social consequences after stroke due to the lack of ability to communicate. Stroke_sentence_369

Many people who experience communication impairments after a stroke find it more difficult to cope with the social issues rather than physical impairments. Stroke_sentence_370

Broader aspects of care must address the emotional impact speech impairment has on those who experience difficulties with speech after a stroke. Stroke_sentence_371

Those who experience a stroke are at risk of paralysis which could result in a self disturbed body image which may also lead to other social issues. Stroke_sentence_372

30 to 50% of stroke survivors suffer post-stroke depression, which is characterized by lethargy, irritability, sleep disturbances, lowered self-esteem and withdrawal. Stroke_sentence_373

Depression can reduce motivation and worsen outcome, but can be treated with social and family support, psychotherapy and, in severe cases, antidepressants. Stroke_sentence_374

Psychotherapy sessions may have a small effect on improving mood and preventing depression after a stroke, however psychotherapy does not appear to be effective at treating depression after a stroke. Stroke_sentence_375

Antidepressant medications may be useful for treating depression after a stroke. Stroke_sentence_376

Emotional lability, another consequence of stroke, causes the person 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. Stroke_sentence_377

While these expressions of emotion usually correspond to the person's actual emotions, a more severe form of emotional lability causes the affected person to laugh and cry pathologically, without regard to context or emotion. Stroke_sentence_378

Some people show the opposite of what they feel, for example crying when they are happy. Stroke_sentence_379

Emotional lability occurs in about 20% of those who have had a stroke. Stroke_sentence_380

Those with a right hemisphere stroke are more likely to have an empathy problems which can make communication harder. Stroke_sentence_381

Cognitive deficits resulting from stroke include perceptual disorders, aphasia, dementia, and problems with attention and memory. Stroke_sentence_382

A stroke sufferer may be unaware of his or her own disabilities, a condition called anosognosia. Stroke_sentence_383

In a condition called hemispatial neglect, the affected person is unable to attend to anything on the side of space opposite to the damaged hemisphere.Cognitive and psychological outcome after a stroke can be affected by the age at which the stroke happened, pre-stroke baseline intellectual functioning, psychiatric history and whether there is pre-existing brain pathology. Stroke_sentence_384

Epidemiology Stroke_section_51

Stroke was the second most frequent cause of death worldwide in 2011, accounting for 6.2 million deaths (~11% of the total). Stroke_sentence_385

Approximately 17 million people had a stroke in 2010 and 33 million people have previously had a stroke and were still alive. Stroke_sentence_386

Between 1990 and 2010 the number of strokes decreased by approximately 10% in the developed world and increased by 10% in the developing world. Stroke_sentence_387

Overall, two-thirds of strokes occurred in those over 65 years old. Stroke_sentence_388

South Asians are at particularly high risk of stroke, accounting for 40% of global stroke deaths. Stroke_sentence_389

It is ranked after heart disease and before cancer. Stroke_sentence_390

In the United States stroke is a leading cause of disability, and recently declined from the third leading to the fourth leading cause of death. Stroke_sentence_391

Geographic disparities in stroke incidence have been observed, including the existence of a "stroke belt" in the southeastern United States, but causes of these disparities have not been explained. Stroke_sentence_392

The risk of stroke increases exponentially from 30 years of age, and the cause varies by age. Stroke_sentence_393

Advanced age is one of the most significant stroke risk factors. Stroke_sentence_394

95% of strokes occur in people age 45 and older, and two-thirds of strokes occur in those over the age of 65. Stroke_sentence_395

A person's risk of dying if he or she does have a stroke also increases with age. Stroke_sentence_396

However, stroke can occur at any age, including in childhood. Stroke_sentence_397

Family members may have a genetic tendency for stroke or share a lifestyle that contributes to stroke. Stroke_sentence_398

Higher levels of Von Willebrand factor are more common amongst people who have had ischemic stroke for the first time. Stroke_sentence_399

The results of this study found that the only significant genetic factor was the person's blood type. Stroke_sentence_400

Having had a stroke in the past greatly increases one's risk of future strokes. Stroke_sentence_401

Men are 25% more likely to suffer strokes than women, yet 60% of deaths from stroke occur in women. Stroke_sentence_402

Since women live longer, they are older on average when they have their strokes and thus more often killed. Stroke_sentence_403

Some risk factors for stroke apply only to women. Stroke_sentence_404

Primary among these are pregnancy, childbirth, menopause, and the treatment thereof (HRT). Stroke_sentence_405

History Stroke_section_52

Episodes of stroke and familial stroke have been reported from the 2nd millennium BC onward in ancient Mesopotamia and Persia. Stroke_sentence_406

Hippocrates (460 to 370 BC) was first to describe the phenomenon of sudden paralysis that is often associated with ischemia. Stroke_sentence_407

Apoplexy, from the Greek word meaning "struck down with violence", first appeared in Hippocratic writings to describe this phenomenon. Stroke_sentence_408

The word stroke was used as a synonym for apoplectic seizure as early as 1599, and is a fairly literal translation of the Greek term. Stroke_sentence_409

The term apoplectic stroke is an archaic, nonspecific term, for a cerebrovascular accident accompanied by haemorrhage or haemorrhagic stroke. Stroke_sentence_410

Martin Luther was described as having an apoplectic stroke that deprived him of his speech shortly before his death in 1546. Stroke_sentence_411

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. Stroke_sentence_412

Wepfer also identified the main arteries supplying the brain, the vertebral and carotid arteries, and identified the cause of a type of ischemic stroke known as a cerebral infarction when he suggested that apoplexy might be caused by a blockage to those vessels. Stroke_sentence_413

Rudolf Virchow first described the mechanism of thromboembolism as a major factor. Stroke_sentence_414

The term cerebrovascular accident was introduced in 1927, reflecting a "growing awareness and acceptance of vascular theories and (...) recognition of the consequences of a sudden disruption in the vascular supply of the brain". Stroke_sentence_415

Its use is now discouraged by a number of neurology textbooks, reasoning that the connotation of fortuitousness carried by the word accident insufficiently highlights the modifiability of the underlying risk factors. Stroke_sentence_416

Cerebrovascular insult may be used interchangeably. Stroke_sentence_417

The term brain attack was introduced for use to underline the acute nature of stroke according to the American Stroke Association, which has used the term since 1990, and is used colloquially to refer to both ischemic as well as hemorrhagic stroke. Stroke_sentence_418

Research Stroke_section_53

As of 2017, angioplasty and stents were under preliminary clinical research to determine the possible therapeutic advantages of these procedures in comparison to therapy with statins, antithrombotics, or antihypertensive drugs. Stroke_sentence_419

See also Stroke_section_54

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: