Stroke
Stroke is a disease that affects the arteries leading to and within the brain. It is the number five cause of death and a leading cause of disability in the United States.
A stroke occurs when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a clot or bursts (or ruptures). When that happens, part of the brain cannot get the blood (and oxygen) it needs and brain cells begin to die.
F.A.S.T Warning Signs
Use the letters in F.A.S.T. to spot a stroke
- F = Face Drooping – Does one side of the face droop or is it numb? Ask the person to smile. Is the person's smile uneven?
- A = Arm Weakness – Is one arm weak or numb? Ask the person to raise both arms. Does one arm drift downward?
- S = Speech Difficulty – Is speech slurred?
- T = Time to call 911 – Stroke is an emergency. Every minute counts. Call 911 immediately. Note the time when any of the symptoms first appear.
Other Stroke Symptoms
Watch for sudden:
- NUMBNESS or weakness of face, arm, or leg, especially on one side of the body.
- CONFUSION, trouble speaking or understanding speech.
- TROUBLE SEEING in one or both eyes.
- TROUBLE WALKING, dizziness, loss of balance or coordination.
- SEVERE HEADACHE with no known cause.
What are the types of stroke?
Stroke can be caused either by a clot obstructing the flow of blood to the brain (called an ischemic stroke) or by a blood vessel rupturing and preventing blood flow to the brain (called a hemorrhagic stroke). A TIA (transient ischemic attack), or "mini stroke," is caused by a temporary clot. Brain stem and cryptogenic strokes are also listed as types of strokes.
What is an ischemic stroke?
An ischemic stroke occurs when a vessel supplying blood to the brain is obstructed. It accounts for about 87% of all strokes.
The main cause of ischemic stroke is atherosclerosis, or fatty deposits (plaque) that line the vessel walls. Fatty deposits can cause two types of obstruction:
- Cerebral thrombosis is a thrombus (blood clot) that develops at the site of fatty plaque within a blood vessel that supplies blood to the brain.
- Cerebral embolism is a blood clot that forms in the heart or large arteries of the upper chest or neck, or at another location in the circulatory system. Part of the blood clot breaks loose, enters the bloodstream and travels through the brain’s blood vessels until it reaches vessels too small to let it pass. A main cause of embolism is an irregular heartbeat called atrial fibrillation. It can cause clots to form in the heart, dislodge, and travel to the brain.
What is hemorrhagic stroke?
Hemorrhagic strokes make up about 13% of stroke cases. They occur when a weakened vessel ruptures and bleeds into the surrounding brain. The blood accumulates and compresses the surrounding brain tissue.
The two types of hemorrhagic strokes are intracerebral hemorrhage (within the brain) or subarachnoid hemorrhage (between the inner and outer layers of the tissue covering the brain).
Arteriovenous malformation (AVM)
Normally, arteries carry blood containing oxygen from the heart to the brain, and veins carry blood with less oxygen away from the brain and back to the heart. When an arteriovenous malformation (AVM) occurs, a tangle of blood vessels in the brain bypasses normal brain tissue and directly diverts blood from the arteries to the veins.
Cerebral aneurysm
A cerebral aneurysm is a weak area in a blood vessel that usually enlarges. It’s often described as a “ballooning” of the blood vessel. It could also be called a brain aneurysm or intracranial aneurysm. Cerebral aneurysms can rupture and cause bleeding within the brain or surrounding area.
What is a transient ischemic attack (TIA)?
A transient ischemic attack, or TIA, is a temporary blockage of blood flow to the brain. The clot usually dissolves on its own or gets dislodged, and the symptoms usually last less than five minutes.
While a TIA doesn’t cause permanent damage, it’s a “warning stroke” signaling a possible full-blown stroke ahead. When you first notice symptoms, get help immediately, even if symptoms go away.
TIA is a medical emergency with the same symptoms as ischemic and hemorrhagic strokes. Most TIA symptoms last from only a few minutes but can last up to 24 hours. They are often dismissed and not taken seriously.
TIAs, which occur before about 15% of strokes, are considered "warning strokes" — they are associated with additional TIAs, full-blown strokes, or other cardiovascular problems later. Most of these later health problems happen within just days or weeks of the TIA, so early interventions to reduce risk are vital.
What is a brain stem stroke?
Brain stem strokes can have complex symptoms and can be hard to diagnose. A person may have vertigo, dizziness, and severe imbalance without the hallmark of most strokes. They may have weakness on one side of the body. Vertigo dizziness symptoms or imbalance usually occur together; dizziness alone is not a sign of stroke. A brain stem stroke can also cause double vision, slurred speech, and decreased consciousness.
Only a half-inch in diameter, the brain stem controls all basic activities of the central nervous system: consciousness, blood pressure, and breathing. All motor control for the body flows through it. Brain stem strokes can impair any or all these functions. More severe brain stem strokes can cause locked-in syndrome, a condition in which survivors can move only their eyes.
If a stroke in the brain stem results from a clot, the faster blood flow can be restored, the better the chances for recovery.
Like all strokes, brain stem strokes produce a wide spectrum of deficits and recovery. Whether a survivor has minor or severe deficits depends on the location of the stroke within the brain stem, the extent of injury, and how quickly treatment is provided.
Risk factors for brain stem stroke are the same as for strokes in other areas of the brain: high blood pressure, diabetes, heart disease, atrial fibrillation, and smoking. Similarly, brain stem strokes can be caused by a clot or a hemorrhage. Rare causes include injury to an artery due to sudden head or neck movements.
Recovery is possible. Because brain stem strokes don’t usually affect language ability, the patient is often able to participate more fully in rehabilitation. Double vision and vertigo usually resolve after several weeks of recovery in mild to moderate brain stem strokes.
What is a cryptogenic stroke?
In most cases, a blood clot that blocks blood flow to the brain causes a stroke. But in some instances, the cause can’t be determined. Strokes without a known cause are called cryptogenic.
About 1 in 4 stroke survivors will likely have another stroke. That’s why it’s important for a health care team to find a definitive diagnosis and potential risk factors to provide targeted treatment to prevent recurrent strokes. So be sure to work with your health care team.
The information and resources below are for you and your loved ones to partner with your health care team and find answers about cryptogenic stroke.
It’s estimated that about 1 in 3 ischemic strokes are cryptogenic.
Some studies suggest that the incidence of cryptogenic stroke is higher in African Americans (two times more likely) and Hispanics (46% more likely).
Possible hidden causes of stroke
- Irregular heartbeat (atrial fibrillation) – AFib patients are at a five times greater risk for stroke.
- Heart structure problems (such as patent foramen ovale)
- Hardening of the arteries (large artery atherosclerosis)
- Blood clotting disorder (thrombophilia)
Managing Risky Conditions
Atherosclerosis: Atherosclerosis can lead to two types of ischemic stroke.
Atherothrombotic stroke is the most common. Sometimes, plaque in a blood vessel breaks. Blood clots can form where the plaque ruptures. These clots can become large, reducing or blocking blood flow. When blood flow to the brain is blocked, a stroke occurs.
Sometimes a blood clot or other particle breaks away from the rupture site. The bloodstream carries that wandering clot or particle (called an embolus). When it lodges, blocking blood flow in an artery leading to or in the brain, it results in an embolic stroke. However, most embolic strokes are from blood clots that form due to atrial fibrillation and then enter the bloodstream.
Risk factors for atherosclerosis
Males and people with a family history of premature cardiovascular disease have an increased risk of atherosclerosis. Other risk factors include:
- High blood pressure: Damages the lining of blood vessels, making them susceptible to atherosclerosis
- High blood cholesterol and triglycerides
- Diabetes mellitus
- Cigarette smoking and exposure to tobacco smoke (the chemicals in cigarettes can cause damage to blood vessels, speeding up the process of plaque buildup)
- Unhealthy eating habits
- Older age: In men, the risk increases after age 45; in women the risk increases after the age 55.
- Family history
- Physical inactivity
Atrial fibrillation: Atrial fibrillation is a quivering or irregular heartbeat, or arrhythmia. Atrial fibrillation, also known as AFib or AF, can lead to blood clots, stroke, heart failure, and other heart-related complications. More than 12 million people are projected to have AFib by 2030.
High blood pressure: High blood pressure is when blood flows with too much force, putting more pressure on the arteries. This excess pressure stretches the arteries beyond a healthy limit and can cause small tears. The body then kicks into an injury-healing mode to repair the tears with scar tissue. But the scar tissue traps substances that form plaque and can lead to blockages, blood clots, and hardened, weakened arteries. Several factors can increase your risk of high blood pressure, including family history, age, lack of physical activity, poor diet, social determinants, gender-related risk patterns, obesity and drinking too much alcohol.
Social Determinants of Health (SDoH) and Risk Factors
Health equity: Everyone should have an optimal, just opportunity to be healthy. But this is not the reality for many people of color and others whose health suffers because of social factors beyond their control. People suffer when they lack access to quality care, nutritious food, and other basic health needs.
SDoH and stroke risk: The cumulative effect of several social factors can more than double the risk of stroke in people under 75 years of age. Research has examined the impact of living in a poor or rural area, having low education or income level, being Black, or lacking health insurance.
Environment, culture and other SDoH roles in heart health: SDoH influence where and how people live, learn, work, and play. They provide context to a person’s life. They can play just as big a role in affecting health as medications and physical lifestyle changes.
Sources
- https://www.stroke.org/en/about-stroke/stroke-risk-factors
- https://www.stroke.org/en/
- https://www.stroke.org/en/about-stroke/stroke-symptoms
- https://www.stroke.org/en/about-stroke/types-of-stroke/ischemic-stroke-clots
- https://www.stroke.org/en/about-stroke/types-of-stroke/brain-stem-stroke
- https://www.stroke.org/en/about-stroke/types-of-stroke/hemorrhagic-strokes-bleeds
- https://www.stroke.org/en/about-stroke/types-of-stroke/tia-transient-ischemic-attack
- https://www.stroke.org/en/about-stroke/types-of-stroke/cryptogenic-stroke