Widder B, Kleiser B, Krapf H
Department of Neurology, University of Ulm, Germany.
Stroke. 1994 Oct;25(10):1963-7. doi: 10.1161/01.str.25.10.1963.
Patients with internal carotid artery occlusions and highly impaired cerebrovascular reactivity have been identified as having an increased risk of stroke. It is still unclear, however, whether cerebral hemodynamics may be restored in the course of time by the development of collaterals.
During a 5-year period we assessed cerebrovascular reactivity in 452 carotid occlusions by transcranial Doppler CO2 testing. Ninety-eight patients could be reinvestigated at least once after 2 to 58 months (mean follow-up time, 26 months).
On admission, patients with recent transient ischemic attack or stroke (< or = 3 months) as well as patients with contralateral carotid stenoses of 80% diameter reduction or greater and occlusions revealed a significantly higher incidence of impaired CO2 reactivity (P < .0001 and P < .01, respectively). During follow-up, 64% of the patients with no or minor contralateral carotid stenoses, but only 22% of the patients with bilateral carotid occlusions, showed a spontaneous improvement in cerebrovascular reactivity (P < .001), mainly during the first few months. In six of eight patients cerebral hemodynamics on the occluded side improved after endarterectomy of a contralateral high-grade carotid stenosis. Five of the patients who did not undergo surgery developed a stroke during follow-up, with three of them occurring in patients with permanently exhausted cerebrovascular reactivity.
In the majority of patients with carotid occlusions an initially impaired cerebrovascular reactivity improves spontaneously with time. This could influence therapeutic decisions: During the first few months antihypertensive treatment may be avoided in such cases until a reestablished reactivity can be demonstrated. If cerebral hemodynamics remain depleted, extracranial-intracranial bypass surgery or endarterectomy of an asymptomatic contralateral high-grade carotid stenosis could be helpful.
已确定颈内动脉闭塞且脑血管反应性严重受损的患者中风风险增加。然而，尚不清楚随着时间推移侧支循环的形成是否可恢复脑血流动力学。
在5年期间，我们通过经颅多普勒二氧化碳检测评估了452例颈动脉闭塞患者的脑血管反应性。98例患者在2至58个月（平均随访时间26个月）后至少接受了一次复查。
入院时，近期有短暂性脑缺血发作或中风（≤3个月）的患者以及对侧颈动脉直径减少80%或更多的狭窄和闭塞患者，二氧化碳反应性受损的发生率显著更高（分别为P<.0001和P<.01）。随访期间，对侧无或轻度颈动脉狭窄的患者中有64%，但双侧颈动脉闭塞的患者中只有22%显示脑血管反应性自发改善（P<.001），主要在最初几个月。在8例患者中的6例中，对侧重度颈动脉狭窄行内膜切除术后，闭塞侧的脑血流动力学得到改善。未接受手术的5例患者在随访期间发生了中风，其中3例发生在脑血管反应性永久耗尽的患者中。
大多数颈动脉闭塞患者最初受损的脑血管反应性会随时间自发改善。这可能会影响治疗决策：在这种情况下，最初几个月可避免降压治疗，直到证明反应性恢复。如果脑血流动力学仍然不足，颅外-颅内搭桥手术或无症状对侧重度颈动脉狭窄的内膜切除术可能会有帮助。
