Strokes: What They Are & How to Prevent Them
Crescent Regional Hospital & Crescent Senior Center Recognize
National Brain Awareness Month
What is a stroke?
A stroke, disrupted circulation that kills brain tissue, can leave neurological impairments including paralysis, partial or total loss of language, and severe cognitive deficits. In the United States, stroke is the fifth leading cause of death. Although strokes are sudden, the brain injury they inflict typically evolves over the course of hours or even days. Prompt, effective treatment can mean the difference between a good recovery and disability or death.
Ischemic strokes, which occur when blood flow to part of the brain is blocked by a clot, are most common, accounting for 80% of the total. The clot may originate in the heart (cardioembolic stroke), often due to disturbed heart rhythm, and travel through the bloodstream to lodge in a cerebral artery. Or it may result from atherosclerosis—a clot breaks off from arterial plaques of fatty material within or outside the brain. Atherosclerosis can also narrow brain arteries, making them more vulnerable to blockage. The effects of a stroke depend on where blockage occurs and the size of the blocked artery. A clot on one side of the brain may cause weakness, paralysis, or sensory loss on the opposite side of the body, and possibly loss of speech. If it occurs in an artery supplying the back of the brain, dizziness, memory loss, and gait and swallowing disturbances are frequent. Obstructing a small artery deep in the brain, a lacunar stroke, typically has more limited consequences.
Hemorrhagic strokes are less common, but more often severe. A ruptured blood vessel bleeds directly into the brain (intracerebral hemorrhage) or into the space between brain and skull (subarachnoid hemorrhage). In most intracerebral hemorrhages, the artery wall has been weakened or damaged by chronic high blood pressure. The usual cause of subarachnoid hemorrhage is an aneurysm—a weak spot in the artery wall.
Because hemorrhagic strokes often affect large brain areas, their consequences are frequently widespread and worsen rapidly.
Hemorrhagic Stroke Damage
The damage inflicted by hemorrhagic stroke is less well understood. The initial symptoms of intracerebral hemorrhage reflect brain irritation by blood from ruptured vessels. As the mass of blood (hematoma) grows, increasing pressure damages brain tissue. Subarachnoid hemorrhage, trapped under the inelastic skull, exerts similar pressure.
Time is of the essence. Stroke symptoms—sudden dizziness, confusion, severe headache, difficulty speaking, double vision, weakness, numbness or paralysis of an arm, leg or face, especially on one side—demand immediate medical attention. Ischemic and hemorrhagic stroke have similar symptoms but need very different treatment, and the first necessity is distinguishing between them by CT scan or magnetic resonance imaging (MRI). Depending on the location of the hematoma and the degree of edema, surgery may be used to relieve pressure by drilling a hole through the skull or placing a shunt to drain fluid.
Protect your Brain
Prevention is better than the best treatment and we understand that at Crescent Regional Hospital. High blood pressure is a powerful risk factor for both kinds of stroke. Reduce it (ideally to 120/80mmHg), with a healthy lifestyle and medication if necessary. Here are some other things you can do, if you haven't already, to prevent a stroke:
Get effective treatment for coronary heart disease and diabetes.
Reduce heart attack risk to protect against stroke: control weight and cholesterol, and exercise regularly. A heart-healthy diet—the vegetable-based Mediterranean diet in particular— has been shown to lower the likelihood of stroke as well.
Avoid alcohol in excess (more than one drink daily for women, two for men).
Talk to your doctor: Atrial fibrillation, a common heart rhythm disturbance, triples ischemic stroke risk unless treated with an anticoagulant—a drug to prevent clots from forming.