首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
医学
You can have too much of a good thing, it seems—at least when it comes to physiotherapy after a stroke. Many doctors believe tha
You can have too much of a good thing, it seems—at least when it comes to physiotherapy after a stroke. Many doctors believe tha
admin
2013-10-31
52
问题
You can have too much of a good thing, it seems—at least when it comes to physiotherapy after a stroke. Many doctors believe that it is the key to recovery; exercising a partially paralyzed limb can help the brain "rewire" itself and replace neural connections destroyed by a clot in the brain.
But the latest animal experiments suggest that too much exercise too soon after a brain injury can make the damage worse. "It’ s something that clinicians are not aware of," says Timothy Schallert of the University at Austin, who led the research.
In some trials, stroke victims asked to put their good arm in a sling—to force them to use their partially paralyzed limb—had made much better recoveries than those who used their good arm. But these patients were treated many months after their strokes. Earlier intervention, Schallert reasoned, should lead to even more dramatic improvements.
To test this theory, Schallert and his colleagues placed tiny casts on the good forelimbs of rats for two weeks immediately after they were given a small brain injury that partially paralyzed one forelimb. Several weeks later, the researchers were astonished to find that brain tissue surrounding the original injury had also died. "The size of the injury doubled. It’ s a very dramatic effect. " says Schallert.
Brain-injured rats that were not forced to overuse their partially paralyzed limbs showed no similar damage, and the casts did not cause a dramatic loss of brain tissue in animals that had not already suffered minor brain damage. In subsequent experiments, the researchers have found that the critical period for exercise-induced damage in rats is the first week after the initial brain injury.
The spreading brain damage witnessed by Schaller’ s team was probably caused by the release of glutamate, a neurotransmitter, from brain cells stimulated during limb movement. At high doses, glutamate is toxic even to healthy nerve cells. And Schallert believes that a brain injury makes neighboring cells unusually susceptible to the neurotransmitter’ s toxic effects.
Randolph Nudo of the University of Texas Health Science Center at Houston, who studies brain injury in primates, agrees that glutamate is the most likely culprit. In experiments with squirrel monkeys suffering from stroke-like damage, Nudo tried beginning rehabilitation within five days of injury. Although the treatment was beneficial in the long run, Nudo noticed an initial worsening of the paralysis that might also have been due to brain damage brought on by exercise.
Schallert stresses that mild exercise is likely to be beneficial however soon it begins. He adds that it is unclear whether human victims of strokes, like brain-injured rats, could make their problems worse by exercising too vigorously, too soon.
Some clinics do encourage patients to begin physiotherapy within a few weeks of suffering a traumatic head injury or stroke, says David Hovda, director of brain injury research at the University of California, Los Angeles. But even if humans do have a similar period of vulnerability to rat, he speculates that it might be possible to use drugs to block the effects of glutamate.
Schallert would probably advise clinicians______.
选项
A、to administer drugs to block the effects of glutamate
B、to be watchful of the amount of exercise for stroke victims
C、to prescribe vigorous exercise to stroke victims one week after injury
D、to reconsider the significance of physiotherapy to brain damage
答案
B
解析
倒数第二段Schallert强调mild exercise可能有益,同时又指出it is unclear whether hu—man victims of strokes…,言外之意是注意运动量,故B项正确。
转载请注明原文地址:https://kaotiyun.com/show/RLU3777K
本试题收录于:
医学博士外语题库考研分类
0
医学博士外语
考研
相关试题推荐
Ihadneverbeeninthepublicwardofahospitalbefore,anditwasmyfirstexperienceofdoctorswhohandleyouwithoutspeak
A、Theyarelarger.B、Theydonothavestrictrules.C、Theygiveprivilegestodepartmentalmajors.D、Theyareeasiertouse.C录音
Theteachertriedhardtoreadthe______handwritinginherstudents’testpapers.
A、Hefailedtodefendhispaper.B、Hehadgotableedingfinger.C、Hecuthisfingerwithaknife.D、Hehadapapercut.D对话中男士讲
A、Discussingacase.B、Defyingadiagnosis.C、Performingasurgery.D、Talkingwiththepatient.A该对话讨论的是某种疾病的症状(diagnosis),因此他们应
TheSupremeCourt’sdecisionsonphysician-assistedsuicidecarryimportantimplicationsforhowmedicineseekstorelievedyin
Socialanxiety,initsmanyforms,isepidemic.Nearlyoneinfourmenandoneineightwomenreporthighanxietywhengoingout
Microsoftisnolongertheworld’sbiggestcompany【C1】______marketcapitalization.ThreeotherU.S.companieshaveovertaken【C
A、Doctorsandnurses.B、Findingahospitalteacher.C、Theschoolteacher.D、Newmedicalinstruments.B从“Mostchildreninterviewe
Theschoolteachersarerequiredto______themarkedexaminationpapersintopassesandfailures.
随机试题
在数据库技术中,实体集之间的联系可以是一对一、一对多或多对多,那么“部门”和“职工”的联系为________。
引起病毒性心肌炎的病毒最常见的是()
异常气象条件作业包括高温作业、高温强热辐射作业,高温高湿作业等。下列生产场所中,有高温强热辐射作业的场所的是()。
银行存款序时核算的要求有()。
“理万金分文不沾“、“常在河边走,就是不湿鞋”,这两句话体现的会计职业道德是()。
下列参加国际展览的入境物品中,应实施检验检疫的有( )。
按照上海证券交易所上市公司行业分类,下列属于工业的行业是()。Ⅰ.通信设备Ⅱ.航空航天与国防Ⅲ.海运Ⅳ.机械制造
一般而言,股份制金融机构资金成本最高的筹资方式是()。
对于场依存型认知风格的学生而言,适合的教学方法是()。
Nooneworddemonstratedtheshiftincorporations’attentioninthemid-1990sfromprocessestopeoplemorevividlythanthesi
最新回复
(
0
)