Contact   |    Careers   |    Employees   |    Physicians





Stroke Center - What is a Stroke

What happens during a Stroke?

Brain cells are deprived of Oxygen and if they do not get the oxygen needed, they begin to die. The result is damage to the affected areas of the brain. The longer the brain cells are deprived of blood and oxygen, the greater the chance of damage to the brain.
Disabilities, such as difficulty moving, speaking or thinking, or even death, may result.

What is an Ischemic Stroke?

Ischemic stroke is the most common type of stroke.
An ischemic stroke occurs when a blood clot blocks an artery, cutting the flow of oxygen-rich blood to a part of the brain causing brain cells in the affected area to die. Disabilities such as trouble moving, speaking, thinking or even death may result. 

There are two types of ischemic strokes: embolic and thrombotic.
In an embolic stroke, a blood clot or plaque fragments forms somewhere in the body) usually the heart or in the large arteries in the neck leading to the brain) and moves through the bloodstream to the brain. Once in the brain, the clot blocks a blood vessel causing a stroke.

A thrombotic stroke is a blood clot that does not travel but forms inside an artery which supplies blood to the brain. The clot interrupts the blood flow causing a stroke. The longer brain cells are deprived of blood and oxygen, the greater the damage to the brain.
Hemorrhagic Stroke
Hemorrhagic strokes are caused by a blood vessel bursting in the brain resulting in blood spilling into the brain. High blood pressure and brain aneurysms can cause a blood vessel to be weak and result in this type of stroke. The bleeding causes brain cells in the affected part of the part brain affected,  to no longer work correctly.  An aneurysm is a weak spot on the wall of an artery that may balloon out, forming a thin-walled bubble.  The aneurysm can burst, leaking blood into the brain.
A subarachnoid hemorrhage is another type of hemorrhagic stroke, a blood vessel bursts near the surface of the brain and blood pours into the area around the outside of the brain, injuring brain cells in the vicinity. This type of stroke is usually the result of a burst aneurysm.

What is a TIA?

A Transient Ischemic Attack (TIA) is a transient episode of neurological dysfunction caused by ischemia (loss of blood flow). TIAs are frequently referred to as mini strokes .
TIAs have the same underlying cause as an ischemic stroke—there is a temporary disruption of cerebral blood flow.  Symptoms include weakness or numbness on one side, loss of vision, slurred speech and confusion. But unlike a stroke the symptoms of a TIA resolve within a few minutes to 24 hours after the episode. Having a TIA is a risk factor and must never be ignored, as it may eventually leading to stroke.

What are the risk factors of Stroke?

Risk factors include high blood pressure, high cholesterol, heart disease, diabetes, smoking, heavy alcohol use, physical inactivity and obesity, irregular heartbeat and a family history of stroke.


Did you know?

  • Stroke is the fourth leading cause of death in the United States.
  • Among the estimated 5.1 million stroke survivors, many are afflicted with serious long-term disability.
  • The annual economic cost of strokes in the US is estimated at $57.9 billion.
It is important to know the warning signs of stroke and teach them to your friends and family. If someone is having a stroke, call 911 immediately! Time lost is brain lost!
© Copyright 2014 Sibley Memorial Hospital