Stroke
Other names	Cerebrovascular accident (CVA), cerebrovascular insult (CVI), brain attack
CT scan of the brain showing a prior right-sided ischemic stroke from blockage of an artery. Changes on a CT may not be visible early on.[1]
Specialty	Neurology, stroke medicine
Symptoms	Inability to move or feel on one side of the body, problems understanding or speaking, dizziness, loss of vision to one side[2][3]
Complications	Persistent vegetative state[4]
Causes	Ischemic (blockage) and hemorrhagic (bleeding)[5]
Risk factors	Age,[6] high blood pressure, tobacco smoking, obesity, high blood cholesterol, diabetes mellitus, previous TIA, end-stage kidney disease, atrial fibrillation[2][7][8]
Diagnostic method	Based on symptoms with medical imaging typically used to rule out bleeding[9][10]
Differential diagnosis	Low blood sugar[9]
Treatment	Based on the type[2]
Prognosis	Average life expectancy 1 year[2]
Frequency	42.4 million (2015)[11]
Deaths	6.3 million (2015)[12]

Stroke (also known as a cerebrovascular accident (CVA) or brain attack) is a medical condition in which poor blood flow to the brain causes cell death.^[5] There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding.^[5] Both cause parts of the brain to stop functioning properly.^[5]

Signs and symptoms of 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.^[2][3] Signs and symptoms often appear soon after the stroke has occurred.^[3] If symptoms last less than one or two hours, the stroke is a transient ischemic attack (TIA), also called a mini-stroke.^[3] Hemorrhagic stroke may also be associated with a severe headache.^[3] The symptoms of stroke can be permanent.^[5] Long-term complications may include pneumonia and loss of bladder control.^[3]

The biggest risk factor for stroke is high blood pressure.^[7] Other risk factors include high blood cholesterol, tobacco smoking, obesity, diabetes mellitus, a previous TIA, end-stage kidney disease, and atrial fibrillation.^[2][7][8] Ischemic stroke is typically caused by blockage of a blood vessel, though there are also less common causes.^[13][14][15] Hemorrhagic stroke is caused by either bleeding directly into the brain or into the space between the brain's membranes.^[13][16] Bleeding may occur due to a ruptured brain aneurysm.^[13] Diagnosis is typically based on a physical exam and supported by medical imaging such as a CT scan or MRI scan.^[9] 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.^[10] Other tests such as an electrocardiogram (ECG) and blood tests are done to determine risk factors and rule out other possible causes.^[9] Low blood sugar may cause similar symptoms.^[9]

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.^[2] Aspirin or statins may be recommended by physicians for prevention.^[2] Stroke is a medical emergency.^[5] Ischemic strokes, if detected within three to four-and-a-half hours, may be treatable with medication that can break down the clot,^[2] while hemorrhagic strokes sometimes benefit from surgery.^[2] 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.^[2]

In 2023, 15 million people worldwide had a stroke.^[17] In 2015, there were about 42.4 million people who had previously had stroke and were still alive.^[11] Between 1990 and 2010 the annual incidence of stroke decreased by approximately 10% in the developed world, but increased by 10% in the developing world.^[18] 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).^[12] About 3.0 million deaths resulted from ischemic stroke while 3.3 million deaths resulted from hemorrhagic stroke.^[12] About half of people who have had stroke live less than one year.^[2] Overall, two thirds of cases of stroke occurred in those over 65 years old.^[18]

Classification

Stroke can be classified into two major categories: ischemic and hemorrhagic.^[19] Ischemic stroke is caused by interruption of the blood supply to the brain, while hemorrhagic stroke results from the rupture of a blood vessel or an abnormal vascular structure. About 87% of stroke is ischemic, with the rest being hemorrhagic. Bleeding can develop inside areas of ischemia, a condition known as "hemorrhagic transformation." It is unknown how many cases of hemorrhagic stroke actually start as ischemic stroke.^[2]

Definition

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",^[20] although the word "stroke" is centuries old. 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.^[2] 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.^[21]

Ischemic

Zdroj:https://en.wikipedia.org?pojem=Acute_stroke_imaging
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