无症状性中风（silent stroke）是指无明显临床表现的脑卒中。事实上，无症状性中风并非完全无症状，只不过是病情较轻而容易被医生和/或患者所忽略。无症状性中风不仅可以增加患者跌倒的可能性，亦可影响老年人的灵活性，反复发作者还可损害记忆力和诱发痴呆。因此，采取措施预防无症状性中风对改善老年人的健康状况和生活质量具有非常重要的意义。

哥伦比亚大学的研究人员对1,238名老年人进行为期６年的研究发现，在这些平均年龄为70左右的老年人中，43％的人极少参加体育锻炼，36％仅仅是经常散步或打高尔夫，21％的人则经常进行慢跑、游泳或打网球等中等强度的运动。经脑扫描检查发现，1,238名老年人有16％被证明既往发生过无症状性中风，后者的发病率又以极少参加体育锻炼者最高，经常参加中等强度运动组的老年人最低，仅仅是经常散步或打高尔夫球的老年人则介于两组之间。进一步分析发现，经常参加中等强度体育运动的老年人患无症状性中风的概率较极少体育运动者低40％，但极少参加体育活动组之老年人无症状性中风的发病率与仅经常参加散步等轻微活动的老年人却无明显差异。

上述结果提示中等强度运动有利于预防无症状性中风。

Exercise May Protect the Brain From 'Silent Strokes'

Moderate to intense physical activity cuts seniors' risk by 40 percent, study finds

WEDNESDAY, June 8 (HealthDay News) -- Jogging, swimming, biking or other moderate to intense physical activity may protect the brain from "silent strokes," or small brain lesions that can lead to mental decline and increase the chances of a future stroke, a new study suggests.

"These silent strokes are more significant than the name implies because they have been associated with an increased risk of falls and impaired mobility, memory problems and even dementia, as well as stroke," study author Dr. Joshua Z. Willey of Columbia University said in a news release from the American Academy of Neurology.

"Encouraging older people to take part in moderate to intense exercise may be an important strategy for keeping their brains healthy," he said.

For the study, Willey and his fellow researchers compiled information on the exercise habits of 1,238 people who had never had a stroke. About 43 percent said they did no regular exercise; 36 percent did light physical activity, such as golf or walking; and 21 percent said they did moderate to intense exercise, such as tennis, swimming, racquetball, hiking or jogging on a regular basis.

About six years later, researchers scanned the brains of the participants, who by then averaged 70 years old. The scans revealed that 16 percent had experienced silent strokes.

Those who reported engaging in moderate to intense activity were 40 percent less likely to have developed these small brain lesions than those who got no regular exercise, the study found. There was no difference in the likelihood of brain lesions between those who engaged in light exercise and those who got no regular physical activity.

"Of course, light exercise has many other beneficial effects, and these results should not discourage people from doing light exercise," Willey noted.

The findings were reported online June 8 in Neurology.

The study also found that the benefits of regular exercise on brain health did not apply to those who did not have health insurance or were on Medicaid. "It may be that the overall life difficulties for people with no insurance or on Medicaid lessens the protective effect of regular exercise," Willey said.

SOURCE: American Academy of Neurology, news release, June 8, 2011