VOA慢速英语-Health Report - When a Stroke Is Silent

This is the VOA Special English Health Report.

A stroke is a loss of blood flow in the brain. There are two kinds of stroke. One is an ischemic stroke. It happens when a blood vessel¹ in the brain gets blocked. The other kind is called a hemorrhagic, or bleeding, stroke. This happens when a blood vessel breaks.

Strokes can cause death or disability. Bleeding strokes are more likely to kill than ischemic strokes. But ischemic strokes are more common -- and doctors can treat them with a drug that breaks up blood clots².

If you think someone is having a stroke, you should seek help immediately. Experts at the United States National Institutes of Health say the treatment has to begin within three hours. But they say people need to get to the hospital within one hour so doctors have time to examine them.

Usually the warning signs appear suddenly. These include trouble walking, weakness especially on one side of the body, difficulty seeing and difficulty speaking.

Yet a recent study showed that seemingly healthy middle-aged³ people can suffer a stroke without immediately knowing it. The study involved about two thousand people. They were the children of men and women who took part in a major research project in Massachusetts called the Framingham Heart Study.

The average age in the new study was sixty-two. The people were examined every four to eight years. They were given M.R.I., magnetic resonance⁴ imaging, tests to inspect for damaged brain tissue and signs of stroke.

The imaging showed that nearly eleven percent of those with no reported stroke had suffered a silent cerebral⁵ infarction, or silent stroke. Silent strokes are brain injuries likely caused by a blockage⁶ that limits blood supply to the brain.

The researchers reported a link between silent stroke and a condition called atrial fibrillation. Atrial fibrillation is the most common cause of abnormal heartbeat in older adults.

Sudha Seshadri at the Boston University School of Medicine says atrial fibrillation more than doubled the risk of a stroke. Doctor Seshadri says the findings show the need for early testing and treatment of conditions that could lead to heart disease.

The study appeared in Stroke, a journal of the American Heart Association.

Other risk factors for a silent stroke are high blood pressure, heart disease, diabetes⁷ and tobacco use.

And that's the VOA Special English Health Report. For more health news, go to voaspecialenglish.com. I'm Steve Ember.

1 vessel   

n.船舶；容器，器皿；管，导管，血管

参考例句：

• The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
• You should put the water into a vessel.你应该把水装入容器中。

2 clots   

n.凝块( clot的名词复数 )；血块；蠢人；傻瓜v.凝固( clot的第三人称单数 )

参考例句：

• When you cut yourself, blood clots and forms a scab. 你割破了，血会凝固、结痂。 来自《简明英汉词典》
• Milk clots when it turns sour. 奶变酸就凝块。 来自《现代英汉综合大词典》

3 middle-aged   

adj.中年的

参考例句：

• I noticed two middle-aged passengers.我注意到两个中年乘客。
• The new skin balm was welcome by middle-aged women.这种新护肤香膏受到了中年妇女的欢迎。

4 resonance   

n.洪亮；共鸣；共振

参考例句：

• Playing the piano sets up resonance in those glass ornaments.一弹钢琴那些玻璃饰物就会产生共振。
• The areas under the two resonance envelopes are unequal.两个共振峰下面的面积是不相等的。

5 cerebral   

adj.脑的，大脑的；有智力的，理智型的

参考例句：

• Your left cerebral hemisphere controls the right-hand side of your body.你的左半脑控制身体的右半身。
• He is a precise,methodical,cerebral man who carefully chooses his words.他是一个一丝不苟、有条理和理智的人，措辞谨慎。

6 blockage   

n.障碍物；封锁

参考例句：

• The logical treatment is to remove this blockage.合理的治疗方法就是清除堵塞物。
• If the blockage worked,they could retreat with dignity.如果封锁发生作用，他们可以体面地撤退。

7 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。