[ti:Battling a Stroke, and the Clock ] [ar:Steve Ember] [al:Health Report] [by:51VOA.COM] [00:00.00]This is the VOA Special English [00:02.79]Health Report. [00:04.26]Strokes are a major cause [00:06.98]of death and disability. [00:09.34]A stroke is a loss of [00:12.15]blood flow in the brain. [00:13.62]There are two kinds. [00:16.03]An ischemic stroke happens [00:18.35]when a blood vessel [00:19.96]in the brain gets blocked. [00:22.10]A hemorrhagic, or bleeding, [00:24.58]stroke happens [00:25.72]when a blood vessel breaks. [00:28.62]People are more likely [00:30.61]to die from a bleeding stroke. [00:33.19]But ischemic strokes [00:35.09]are more common, [00:36.64]and doctors may be able [00:38.68]to treat them. [00:40.19]A drug called tPA can [00:43.38]break up blood clots. [00:45.64]But traditional guidelines say [00:48.30]not to use tPA if more than [00:51.54]three hours have passed [00:53.71]after the first signs of a stroke. [00:57.08]There is a risk that giving a patient [01:00.12]a strong blood thinner [01:02.18]during a stroke can cause bleeding [01:04.88]inside the brain. The longer the wait, [01:08.87]experts say, the more likely [01:11.55]that the risks of treatment [01:14.04]will outweigh the benefits. [01:16.91]But recent findings have suggested [01:19.92]that tPA may be effective [01:23.05]in saving brain tissue [01:25.26]even if three to four [01:27.76]and a half hours have passed. [01:30.57]Some studies have failed [01:32.50]to produce clear evidence [01:34.41]to support treatment [01:36.42]after three hours. [01:37.91]But scientists reported [01:40.00]that the evidence was stronger [01:42.50]when they combined the results [01:45.01]of the four major studies done so far. [01:48.70]The new findings appeared [01:51.52]in the journal Stroke. [01:53.46]The researchers said tPA improved [01:57.61]the chances of a successful result [02:00.66]by thirty-one percent [02:03.17]and produced no change [02:05.54]in the death rate. [02:07.48]Maarten Lansberg at the [02:10.34]Stanford University medical school [02:12.73]in California worked [02:14.64]with scientists [02:15.76]from Belgium and Germany. [02:18.27]One of them worked for a company [02:21.04]that makes tPA for use in Europe. [02:25.13]The United States National Institutes [02:28.10]of Health paid for the study. [02:30.96]If you think someone is having a stroke, [02:34.28]you should seek help immediately. [02:37.30]The warning signs usually [02:40.05]appear suddenly. [02:41.90]These include trouble walking, [02:44.66]weakness especially [02:47.06]on one side of the body, [02:48.94]difficulty seeing [02:50.66]and difficulty speaking. [02:53.71]Yet people who seem healthy [02:56.67]can suffer a stroke without [02:59.22]even knowing it. [03:00.92]A study published in Stroke [03:03.30]last year involved [03:05.16]about two thousand people [03:07.36]with an average age of sixty-two. [03:10.66]Brain imaging showed [03:13.28]that nearly eleven percent of them [03:16.03]had suffered what is known as [03:18.06]a silent stroke. [03:20.32]The researchers reported a link [03:23.39]between silent strokes and a condition [03:27.05]called atrial fibrillation. [03:29.71]This is the most common cause [03:32.53]of abnormal heartbeat in older adults. [03:36.65]Other risk factors for a silent stroke [03:40.91]are high blood pressure, heart disease, [03:44.52]diabetes and tobacco use. [03:48.44]And that's the VOA Special English [03:54.23]Health Report. I'm Steve Ember.