Nearly 800,000 people in the United States each year have a stroke, resulting in 160,000 deaths from stroke-related causes according to the National Institute of Neurological Disorders and Strokes. This makes stroke the fifth leading cause of death in the United States. In addition, strokes are the leading cause of serious long-term adult disability; over two-thirds of survivors are affected by a temporary, or permanent, disability.
According to the Centers for Disease Control and Prevention, every 40 seconds someone in the United States has a stroke, and every four minutes, someone dies of a stroke. Of the nearly 800,000 people that have a stroke, 610,000 experience a stroke for the first time. Approximately 90 percent of strokes are ischemic strokes. These strokes occur when the flow of blood to the brain is blocked.
Recognizing the warning signs of a stroke is vital. And the faster emergency medical intervention is sought, and treatment begins, the better the possible outcome. In fact, patients who arrive at the emergency room within three hours of the first signs of stroke are often less disabled after three months than patients whose care was delayed. If any you or someone you love experiences any warning signs of a stroke, don’t delay — call 911 immediately.
What Is a Stroke?
The brain must have a constant supply of oxygen and blood delivered by blood vessels; when the supply is cut off or interrupted, brain cells begin to die. This, in essence, is a stroke. Think of a stroke as a brain attack — similar in many ways to a heart attack. In both cases, blocked blood vessels often cause the injury to the organ, which results in limited or no circulation of blood.
Strokes can occur closer to the surface of the brain or can occur deep within the brain. The damage experienced varies widely from person to person. The type of stroke, where it occurs, and the severity, all play a role in the prognosis and recovery timeline.
Strokes fall into two general categories: ischemic strokes and hemorrhagic strokes. Ischemic strokes are the result of a blockage in a blood vessel in the neck or brain, while hemorrhagic strokes are the result of bleeding into the brain. Let’s take a closer look at the most common types of strokes.
Ischemic Stroke. An ischemic stroke occurs when blood vessels in the brain or the neck are blocked. This blockage cuts off the circulation of blood and oxygen to the brain. In fact, ischemic strokes are by far the most common, with up to 90 percent of all strokes caused by a blockage. There are three leading causes of an ischemic stroke:
Thrombosis: A clot forms inside an artery in the brain or neck due to cholesterol-filled plaque that dislodges and starts to move. One-half to two-thirds of all strokes fall into this category.
Embolism: A clot that moves from another part of the body to the brain, blocking an essential artery.
Stenosis: Severe narrowing of an artery leading to the brain that cuts off the proper circulation of blood and oxygen.
Up to one-fifth of all strokes are a lacunar stroke, according to Harvard Medical School. A lacunar stroke falls into the ischemic stroke category as it is a result of a blockage in a blood vessel; however, this stroke occurs in the tiny arteries deep inside the brain. The pounding pulse of high blood pressure damages these delicate arteries, often causing these strokes.
Fortunately, lacunar strokes have a far better recovery rate than other types with more than 90 percent of survivors recovering significantly within the first 90 days after the stroke. However, it is important to note that this kind of stroke may have very minor symptoms that may be harder to recognize; as with all strokes, immediate emergency medical intervention is necessary for the best results.
Transient Ischemic Attacks (TIA) are also known as a mini stroke. Here, like an ischemic stroke, blood flow is temporarily decreased. These often last for less than five minutes. These mini strokes typically don’t cause lasting symptoms because the blockage is temporary; however, it is still essential to seek emergency care immediately, even if the symptoms clear. TIAs put you at a significantly greater risk for strokes that can cause permanent damage or death.
Hemorrhagic Stroke. Considerably rarer than an ischemic stroke, hemorrhagic strokes are estimated to account for only between 10 and 15 percent of cases. However, they account for between 30 and 60 percent of all stroke-related deaths. Instead of a clot causing a blockage in an artery, a blood vessel ruptures, leaking blood into the brain. The blood then builds up, compressing brain tissue, causing the damage associated with a stroke. There are two main causes of a hemorrhagic stroke: aneurysm and AVM.
Aneurysm. When a cerebral aneurysm bursts, or a weakened blood vessel leaks, a hemorrhagic stroke can occur. Somewhere between 1.5 and 5 percent of the general population has, or will develop, a cerebral aneurysm. However, only between 0.5 and 3 percent will suffer from a brain bleed. High blood pressure is believed to contribute and pose an increased risk.
AVM. Arteriovenous Malformation, or AVM, are typically congenital (but not hereditary). They are believed to occur in less than 1 percent of the population. With AVM, arteries are abnormal, often appearing tangled, causing blood to divert from the arteries to the brain. Twenty-five percent of those with AVM will experience bleeding into the brain causing brain damage and stroke.