Special English 又叫“慢速英语”，是VOA 专为全世界非英语国家初学英语的听众安排的一种简易、规范的英语广播节目。该节目创始于50年代末期，是VOA 的专家们研究如何与世界各地的英语学习者进行交际的产物。它正式开播于1959年10月。当时只面向欧洲和中东，但由于这个节目适合许多国家英语学习者的需要，所以它的广播对象不久就扩大到世界其他地区，并很快在全世界范围内产生了广泛的影响。现在这个节目对欧洲、非洲和拉丁美洲每晚广播一次，对加勒比地区每晚广播一次（星期天除外），对东南亚广播次数最多，每天上午两次，晚上三次。
30多年来，VOA 为了办好Special English节目，进行了大量的调查研究工作，对播音速度、内容及用词范围都作了具体规定，基本上达到了既能为英语学习者提供信息，又不损害英语本身风格的目的，使之成为VOA 独具特色，拥有最大量听众的节目。
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2008.08.13
When a Stroke Is Silent
By / Broadcast date: Wednesday, August 13, 2008
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 vessel in the brain gets blocked. The other kind is called a hemorrhagic, or bleeding, stroke. This happens when a blood vessel breaks.
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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 clots.
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-aged 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 resonance 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 cerebral infarction, or silent stroke. Silent strokes are brain injuries likely caused by a blockage 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, diabetes and tobacco use.
And that's the VOA Special English Health Report. For more health news, go to www.voaspecialenglish.com. I'm Steve Ember.
