Emergent Stroke Therapy

Stroke is the third leading cause of death in the United States behind high blood pressure and cancer. Every 45 seconds someone in the United States has a stroke and every three minutes someone dies from a stroke. In the U.S. alone, an estimated 600,000 individuals will suffer a new or recurrent stroke each year –160,000 will die. More than one million American stroke survivors struggle with serious disabilities, including loss of speech and/or language problems, weakness or paralysis, loss of balance or coordination, and confusion and memory loss. All are common impairments in the aftermath of a stroke.

Once it was believed that little could be done to treat stroke. Now we know that if a stroke victim receives emergency care thin the first three to six hours of the first symptom, the disabling, long-term effects of stroke may be avoided or greatly reduced. Unfortunately, many people do not recognize the warning signs of stroke or do not know that immediate emergency care can greatly improve their chance of recovery.

Studies show that the average person waits 13 hours after experiencing the first symptoms of stroke before seeking medical care, and 42 percent of patients wait as long as 24 hours. It is critical to recognize the symptoms of stroke and seek immediate emergency attention.

What causes stroke?
A stroke occurs when a blood vessel carrying oxygen and nutrients to the brain is blocked by a clot or bursts, causing the brain to starve. If deprived of oxygen for even a short period of time, the brain nerve cells will start to die. Once the brain cells die from a lack of oxygen, the part of the body that section of the brain controls is affected through paralysis, language, motor skills, or vision.
There are two types of stroke:

  1. Blood clots that block the artery are ischemic (is-KEM-ik) strokes and the most common type, causing between 70-80 percent of all strokes.
  2. Second type is when a blood vessel ruptures, it causes a bleeding or hemorrhagic (hem-o-RAJ-ik) stroke. Such strokes are usually the result of a ruptured blood vessel or an aneurysm (a weakened area of a blood vessel that bulges or balloons out).

Sometimes, abnormal tangles of blood vessels in the brain, called arteriovenous malformations (AVM) can rupture and cause a hemorrhagic stroke. Approximately 20 percent of strokes are hemorrhagic. This is the most common type of stroke in young people.

There are also “mini-strokes” known as TIA’s “Transient Ischemic Attacks.” People who have one TIA are likely to have another one. TIAs cause brief stroke symptoms that go away after a few minutes or hours. People often ignore these symptoms, but they are an early warning sign, and 35 percent of those who experience a TIA will have a full blown stroke if left untreated. TIAs should be taken as seriously as stroke.

What are the symptoms of stroke?
The most common symptoms of stroke are:

  • Sudden numbness or weakness in the face, arm and/or leg, especially on one side of the body.
  • Sudden confusion, trouble speaking or understanding speech
  • Sudden trouble seeing, including double vision, blurred vision or partial blindness, in one or both eyes
  • Trouble walking, dizziness, loss of balance or coordination
  • Sudden severe, headache with no known cause

If you experience any of these symptoms, even if they go away quickly, seek immediate emergency help.

Every minute counts!
Although starved of oxygen, brain tissue does not die in the minutes following a stroke. If blocked blood vessels can be opened within three to six hours, the chances of recovery are greatly improved.

What are the risk factors for stroke?

People who are at higher-than-average risk for stroke include those who have:

  • High blood pressure 
  • High blood pressure, or hypertension, puts stress on the walls of blood vessels and can lead to strokes from blood clots or hemorrhage. Half or more of all stroke victims have uncontrolled high blood pressure. Fortunately, this risk factor for stroke can be controlled. Eating a balanced diet, maintaining a healthy weight and exercising regularly can help control high blood pressure. Medications that lower blood pressure also may be prescribed.

  • High Cholesterol 
  • High cholesterol can lead to blockage in the carotid artery that takes blood from the neck to the brain. A piece of this plaque can break off and travel to the brain causing a stroke.

  • Heart Disease 
  • Approximately 15 percent of all stroke victims have a common heart rhythm disorder called atrial fibrillation, that causes the upper chambers of the heart (the atria) quiver instead of beating which allows the blood to pool and clot. If a clot breaks off and enters the blood stream to the brain, a stroke will occur

  • Atherosclerosis
  • When the carotid arteries, the major blood vessels that supply blood to the brain, become clogged with atherosclerotic plaque, the risk for stroke goes up.

  • Personal history of stroke or TIA 
  • People who have already suffered a stroke or TIA are at increased risk of having another. Modifying risk factors for stroke, including lifestyle changes (e.g. exercise, stop smoking), medications and/or other treatments can reduce this risk.

  • Lifestyle risk factors
  • Smoking, excessive alcohol consumption and being overweight are all significant risk factors for stroke. High cholesterol can lead to blockage in the carotid artery that takes blood from the neck to the brain. A piece of this plaque can break off and travel to the brain causing a stroke.

  • Age, Gender and Race
  • The risk of stroke goes up with age, with two-thirds of all strokes occurring in individuals 65 years or older. Twenty-eight percent of stroke occur in people under the age of 65. Males have a slightly higher risk than females although more women die from them. African Americans are at a much higher risk in part because they are at increased risk for obesity, high blood pressure and diabetes which increase the risk for stroke.

  • Family history of stroke or TIA
  • If others in your family have suffered stroke, you may be at higher risk. Regular physical exams, lifestyle changes and medical treatments may reduce this risk.

  • Diabetes
  • People with diabetes are at increased risk for stroke, although keeping diabetes under control with diet and/or medication may help to decrease the risk.

  • Sickle Cell Anemia
  • Sickle cell anemia makes red blood cells less able to carry blood to the body’s tissues and organs, as well as stick to the walls of the blood vessels which can block arteries to the brain causing a stroke.

  • Hyper-Homocysteinemia 
  • Elevated homocysteine levels in the blood have been identified as a risk factor for heart attack and stroke that may be as important as high cholesterol. Homocysteine is a by-product of the process that metabolizes methionine, an amino acid essential in human nutrition.

Stroke Prevention – Carotid Stenting – Carotid Artery Screening

As vascular experts, interventional radiologists treat atherosclerosis, or “hardening of the arteries,” throughout the body. In some patients, atherosclerosis, specifically in the carotid artery in the neck, can lead to ischemic stroke. Plaque in the carotid artery may result in a stroke by either decreasing blood flow to the brain or by breaking loose and floating into a smaller vessel, depriving a portion of the brain of blood flow. In patients at high risk of having a stroke, the narrowed section of the artery may be reopened by an interventional radiologist through angioplasty and reinforced with a stent, thereby preventing the stroke from occurring. Vascular stents are typically made of woven, laser-cut or welded metal that permits the device to be compressed onto a catheter and delivered directly into the hardened artery. In addition to diagnosing and treating those at risk for stroke, interventional radiologists can use their expertise in imaging, angioplasty, and stenting to treat those having an acute stroke.

Patients can also take action to prevent stroke by:

  • Quitting smoking
  • Controlling high blood pressure
  • Lowering cholesterol levels
  • Maintaining a healthy weight
  • Exercising
  • Utilizing appropriate medications such as aspirin and prescription drugs such as anticoagulants
  • Treating carotid artery disease
  • Treating unruptured cerebral aneurysms or arteriovenous malformations
Stroke TreatmentIschemic Stroke

 

If the stroke is due to a blood clot, a clot-busting drug, tPA (tissue plasminogen activator)can be given intravenously to break up or reduce the size of blood clots to the brain. This technique must be performed within three hours from the onset of symptoms.When therapy cannot be initiated within three hours or when treatment with tPA during the first three hours is not sufficient to dissolve the blood clot, interventional radiologists (IR) that specialize in neurological procedures can provide intra-arterial thrombolysis treatment.

Using x-ray guidance, an IR will insert a catheter through a nick in the skin at the groin and advance it through the femoral artery in the leg all the way to the tiny arteries in the brain where they place the clot-busting drug directly on the clot or to break up the clot mechanically.

When given locally this way, the tPA can be administered up to six hoursafter
the onset of stroke symptoms. In many cases, the ambulance drivers will take a stroke victim past the three-hour window directly to the interventional radiology suite for assessment for this direct thrombolytic therapy. Often, a significantly disabled stroke patient who receives this treatment can return to normal life with minimal or no after effects from the stroke.

The interventional radiologist will also assess what caused the clot, such as a clogged carotid or other artery, and can correct the underlying problem to prevent future strokes from occurring. Unfortunately, many hospitals in this country do not have stroke teams that can rapidly assess patients and provide treatment within the three-hour window. Interventional radiologists are actively involved in creating more stroke teams across the country. Stroke teams generally consist of emergency room physicians, neurologists and interventional
radiologists.

Before tPa therapy

After tPa therapy

Hemorrhagic Stroke

Interventional neuroradiologists can also treat ruptured aneurysms inside the brain causing hemorrhage into the subarachnoid space, which can cause stroke or death. During the embolization technique, an interventional neuroradiologist inserts a catheter through a nick in the skin of the groin and advances it to the site of the ruptured blood vessel. An embolizing agent (a substance that clots or closes off the bleeding blood vessel) is injected under X-ray guidance. Most commonly, tiny metal coils are used to embolize and block the abnormal blood vessel or aneurysm. The catheter is withdrawn and the coils remain to provide the occlusion. The same technique can be used to treat aneurysms and AVM before they rupture. Surgery had been the primary treatment available until the platinum coil device was approved by the FDA in 1995.