对于远期效果不大而在临床上有些作用的预防性治疗,很难进行评价。这种情形再加上在医生方面对治疗抱乐观态度和在病人方面愿意有所治疗,乃导致广泛应用未经证实和往往无效的疗法。更坏的是,当某种新事物在理论上看起来更有希望时,缺少正确的评价会使人放弃一些有效的疗法。这些难题没有比预防中风更为明显的了。我们所肯定知道的是,通过检查高血压并给以有效的治疗能减少中风的危险,虽然要付出药物治疗副作用的代价。有证据证明,在一过性局部缺血发作 For the long-term effect is not large and some of the role of preventive treatment, it is difficult to evaluate. This situation, coupled with the optimistic treatment of patients by physicians and their willingness to treat patients, has led to widespread use of unproven and often ineffective treatments. Even worse, when something new seems theoretically more hopeful, the lack of a correct rating can discourage some people from giving up some effective treatment. None of these problems is more evident than the prevention of a stroke. What we are surely aware of is that the risk of stroke can be reduced by examining the high blood pressure and giving effective treatment, albeit at the cost of side effects of medication. There is evidence that transient ischemic attacks