You Can Prevent Stroke
If you’ve ever witnessed someone suffer a stroke, you understand the humbling nature of this disease. It can reduce the mightiest human being to an immobile, helpless creature. Impairment of crucial functions like speech, walking, and control of bowel and bladder can wrench control from the body in a moment.
Even perpetually youthful TV personality Dick Clark was struck down by stroke at age 75, despite the outward appearance of perfect health. Clark’s stroke resulted in a six-week hospital stay and, judging from fragmented reports, significant disability. Stroke can be like a devastating fire that strikes without warning, leaving only smoldering rubble. Stroke can so ravage basic bodily functions that often all you can hope for is to regain a portion through rehabilitation.
The disease process that underlies stroke requires decades—30 or 40 years—to develop. With that much lead time, why aren’t we better able to detect or stop this crippling disease?
The truth is that we are able to predict many, if not most, strokes. Advances in imaging technology allow detection of atherosclerotic plaque that cause stroke years before it becomes a threat. Progress in deciphering the causes of stroke has also leapt forward.
Unfortunately, your neighborhood physician still focuses on diagnosing the crisis rather than anticipating it. Physicians prefer to deal with catastrophes and are just not that interested in prevention. Most physicians ask: “Is it time to operate or not?” The medical community obsesses over procedures like carotid endarterectomy (surgical removal of купить телевизор Hyundai plaque) or carotid stents. Even when a person is afforded the warnings of a “mini-stroke”, or transient ischemic attack (TIA), little more is done once it’s determined that surgery is not necessary—even though this person has high risk for future stroke (50% over 10 years).
Let’s flip-flop this approach to stroke. Procedures represent a failure of prevention!
Where do strokes come from?
Stroke develops when some portion of the brain is deprived of blood. This usually results from a tiny bit of debris that dislodges from an atherosclerotic plaque along the walls of an artery (the same sort that accumulates in coronaries causing heart attack). The sources of debris have been a subject of controversy, but new imaging technologies have settled the question. Any blood vessel that leads from the heart to the brain can be a source. The two carotid arteries on both sides of your neck are a frequent source, as these arteries are prone to develop plaque. (Our discussion will be confined to what are called thromboembolic, or ischemic, strokes, i.e, strokes that occur from plaque that fragments, sending debris to the brain, and will not include the far less common hemorrhagic strokes due to rupture of small vessels in the brain, nor will we discuss atrial fibrillation and other heart causes of stroke. The thromboembolic strokes we discuss cause around 88% of all strokes.)
Over the last 10 years, the aorta has been recognized as another important source of stroke. The aorta is the main artery of the body whose branches go to the head, arms, and legs.
Atherosclerotic plaque is a live tissue that, through poor diet, inactivity, high cholesterol, overweight, etc., grows and becomes progressively more unstable. At some point, plaque fragments. Little bits break away, traveling to the brain. Fractured plaque also exposes its deeper structures to flowing blood, triggering blood clot formation, which in turn can also fragment and go to the brain. Atherosclerotic plaque is a prerequisite for the most common causes of stroke.
If the majority of strokes originate from plaque, why not measure plaque to determine if you’re at risk for stroke? How can we easily, safely, and accurately measure plaque in the carotid arteries and aorta? And if plaque can be measured, can it be shrunk or inactivated to reduce or eliminate risk for stroke?
How can plaque be measured?
Just 20 years ago, the only practical method of identifying plaque in the carotids or aorta was through angiography, requiring catheters inserted into the body to inject x-ray dye. Angiography was impractical as a screening measure.
CT scanning and magnetic resonance imaging (MRI) are emerging as exciting methods of imaging both carotids and aorta. Unfortunately, most centers and physicians are much more focused on the diagnostic uses of these technologies for people who have already suffered stroke or other catastrophe, and application of these devices for preventive uses is still evolving. One exception is when aortic calcification or aortic enlargement is incidentally noted on the increasingly popular CT heart scans; this is an important finding that can signal presence of aortic plaque.
The one test that is widely available and can be performed in just about any center is carotid ultrasound. It’s simple, painless, and precise. Two basic observations can be made:
1. Plaque detection—Atherosclerotic plaque can be clearly visualized. If plaque blocks more than 70% of the diameter of the vessel, or if there are “soft” (unstable) elements in plaque, then stroke risk may be high enough to justify surgery or stents. However, if there are plaques that are less severe, substantial risk for stroke may still be present that can be reduced with preventive measures. 2. Carotid intimal-medial thickness—This is a measure of the thickness of the lining of the carotid artery in areas not involved by plaque, but often precedes the development of mature plaque. Carotid intimal-medial thickness also provides an index of body-wide potential for atherosclerotic plaque that can place you at risk for stroke. The aorta, for instance, cannot be well imaged by surface ultrasound but can still be a source for stroke. Increased carotid intimal-medial thickness and carotid plaque are closely associated with likelihood of aortic plaque. The Rotterdam Study of 4000 participants demonstrated that if carotid intimal-medial thickness is greater than normal (1.0 mm), then you can be at risk for stroke (and heart attack), even if no carotid plaques are detected.
Carotid ultrasound is the one test you should consider that provides the most information with least effort. Ultrasound is harmless, painless, and can be obtained just about anywhere. Even if your doctor disagrees with your request for a carotid ultrasound, an increasing number of mobile services are popping up nationwide that make this test available for around $100. One important point: many scanners and interpreters will only report whether plaque is present or not. While this is important information, you should request that
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