Norris J W, Zhu C Z
Stroke Research Unit, Sunnybrook Medical Centre, University of Toronto, Canada.
J Neurol Neurosurg Psychiatry. 1990 Mar;53(3):235-7. doi: 10.1136/jnnp.53.3.235.
The risk of stroke from carotid stenosis is proportionate to the degree of stenosis, but whether this is a direct and linear relationship is unknown. Using the degree of carotid stenosis in 500 patients with asymptomatic carotid bruits as a continuous variable, we plotted the frequency distribution and related this to the risk of ischaemic cerebral events and the progression of the arterial lesion. There was a bi-modal distribution, with the junction of the two populations at 85% stenosis. The frequency of ischaemic cerebral events was maximal at 75-90% stenosis. Our data suggest that there is a critical degree of carotid stenosis at which stroke risk becomes maximal. This may represent a window of therapeutic opportunity.
颈动脉狭窄导致中风的风险与狭窄程度成正比，但这是否是一种直接的线性关系尚不清楚。我们将500例无症状颈动脉杂音患者的颈动脉狭窄程度作为连续变量，绘制了频率分布，并将其与缺血性脑事件风险及动脉病变进展相关联。结果呈现双峰分布，两个群体的交界点在85%狭窄处。缺血性脑事件的发生率在75%-90%狭窄时最高。我们的数据表明，存在一个关键的颈动脉狭窄程度，此时中风风险达到最大值。这可能代表着一个治疗机会窗口。
