Aneurysm Is Rare, Thrombosis Is Common
Aneurysms with the potential for bleeding are a relatively rare cause of TIAs, which is why I remember Joe’s case so clearly. Most TIAs are due to cholesterol-laden plaques gradually blocking blood flow through a vessel; the TIA symptoms warn that the blockage is becoming severe and a clot or thrombus has begun to form.
The clotting process is like a slow, relentless suicide machine: tiny particles called platelets in the blood begin to gather and aggregate to form a thrombus, the thrombus
steadily mushrooms in size as more platelets land on it, and eventually the blood vessel is completely blocked. This results in an infarction (infarct), which is the death of a mass of brain tissue that is deprived of glucose and oxygen due to lack of blood supply. Nature has given us a powerful clotting process to shield us from excessive blood loss when we have an external injury, but the same process can be lethal if it occurs internally in the heart or brain.
Signs of a Transient Ischemic Attack (TIA) and What to Do When It Occurs
Sudden weakness in any arm or leg.
Sudden changes in sensation (to touch, pain, or heat), speech, or vision.
Acute confusion or memory lapses that last for a few minutes to hours.
Any or all of these symptoms may resolve spontaneously, but this is no reason to rejoice. Go to your doctor or emergency room immediately, preferably accompanied by someone close to you.
Like Joe Smith, many people tend to wait because they usually recover without a hitch from the initial TIA, and when the full-blown stroke strikes it is often too late to treat effectively.
Types of Small and Large Strokes
Thrombosis (clotting).
Embolism (blood clot from the heart is propelled into the brain).
Hemorrhage (bleeding, as from an aneurysm).
Embolism
I already described the mechanism behind clot or thrombus formation and the risk of hemorrhage (bleeding) from an aneurysm. An embolus is a thrombus that initially forms in the heart, often around a diseased heart valve. The thrombus is then mechanically dislodged and propelled by the heart’s pumping action into the big carotid arteries going in a straight line to the head. The embolus flies through the wide carotids but then gets stuck in a slimmer branching artery inside the brain. The
result, like a thrombus, is a stroke called an infarction or infarct. The embolus just sits there, blocking the blood vessel that used to supply the infarcting (dying) group of nerve cells in the brain.
Taken From: The Memory Program How to Prevent Memory Loss
and Enhance Memory Power
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