A&P Tip: Stroke
By Jackie Stack, BSHA, CPC, CPC-I, CPB, CEMC, CFPC, CIMC, CPEDC
A stroke is a “brain attack” that occurs when blood flow to an area of the brain is cut off. Brain cells are deprived of oxygen and begin to die. When brain cells die, abilities controlled by that area of the brain — such as memory and muscle control — are lost. A stroke can happen at any time.
According to the National Stroke Association, nearly 800,000 people experience a new or recurrent stroke each year. How a person is affected by a stroke depends on where the stroke occurs and the extent of damage to the brain. Small strokes may only cause minor problems, such as a temporary weakness of an arm or leg. Larger strokes may cause permanent paralysis on one side of the body or loss of the ability to speak. Some people recover completely from strokes, but more than two thirds of survivors have some type of disability.
There are two types of stroke: hemorrhagic and ischemic. Hemorrhagic strokes are less common, but are responsible for about 40 percent of all stroke deaths.
A hemorrhagic stroke occurs when a brain aneurism bursts or a weakened blood vessel leaks. Blood spills into or around the brain and creates swelling and pressure, damaging cells and tissue in the brain. There are two types of hemorrhagic strokes:
- Intracerebral hemorrhage – The most common hemorrhagic stroke. The bleeding causes brain cells to die and the affected brain part stops working correctly. High blood pressure and aging blood vessels are the most common causes.
- Subarachnoid Hemorrhage – This involves bleeding in the subarachnoid space (area between the brain and tissue covering the brain). It’s most often caused by a burst aneurism, but also may be caused by bleeding disorders, head injuries, blood thinners, or arteriovenous malformation.
Ischemic stroke occurs when a blood vessel carrying blood to the brain is blocked by a blood clot. High blood pressure is the most important risk factor. Ischemic strokes account for about 87 percent of all strokes and can occur two ways:
- Embolic stroke – In an embolic stroke, a blood clot or plaque fragment forms somewhere in the body and travels to the brain. Once in the brain, the clot travels to a blood vessel small enough to block its passage. The clot lodges there, blocking the blood vessel.
- Thrombotic stroke – A thrombotic stroke is caused by a blood clot (large vessel thrombosis and small vessel disease) that forms inside one of the arteries supplying blood to the brain. This is usually seen in people with high cholesterol levels and atherosclerosis.
A transient ischemic attack (TIA) occurs when blood flow to part of the brain stops for a short period of time. This can mimic stroke-like symptoms that last less than 24 hours. Typically TIAs do not cause permanent brain damage, but are a serious warning sign that a stroke may happen in the future and should not be ignored. TIAs are usually caused by low blood flow, a blood clot in another part of the body, or a narrowing of the smaller blood vessels in the brain.
According to the National Stroke Association, 40 percent of people who have a TIA will have an actual stroke. Nearly half of all strokes occur within the first few days after a TIA.
Jackie Stack, BSHA, CPC, CPC-I, CPB, CEMC, CFPC, CIMC, CPEDC, is an ICD-10 specialist at AAPC and a member of the Oil City, Pennsylvania, local chapter.