Keunen R W, Tavy D L, Visée H F, Muskens E B, Edelenbosch R
Department of Neurology and Clinical Neurophysiology, Leyenburg Hospital, Hague, The Netherlands.
Neurol Res. 1998 Sep;20(6):493-8. doi: 10.1080/01616412.1998.11740553.
In carotid artery disease (CAD) the basilar artery (BA) may act as an important intracranial collateral to supply hypoperfused middle cerebral artery (MCA) territories. Transcranial Doppler studies were performed to study the dependency between BA hemodynamics in relation to the MCA perfusion status. BA and MCA blood flow velocities (BFV), pulsatility indices (API) and cerebrovascular reactivity (CVR) were assessed in 40 patients with a progressive MCA hypoperfusion due to progressive CAD. All patients had patent cervical segments of their vertebral arteries with an antegrade vertebral flow profile. Duplex studies were performed to diagnose the severity of CAD. Hypoperfusion of the MCA was diagnosed by the degree of vasoparalysis assessed by a Diamox procedure. Analysis showed that the basilar BFV significantly increased in cases of progressive CAD, the basilar PI decreased but the basilar CVR remained unchanged. However, in cases of bilateral hemodynamic significant CAD and bilateral exhausted CVR in the MCA territory, the basilar artery did not exhibit an increase of BFVs or a decrease of the basilar PI, but the basilar CVR showed a significant decrease. Basilar artery CVR is not impaired if this artery has a function as intracranial collateral in CAD. However in cases of bilateral hypoperfused MCA territories the basilar artery does not function as a collateral pathway. The basilar CVR declines under these circumstances which merely reflects the exhausted hemodynamics in the anterior/posterior borderzones. This situation might lead to an increased stroke risk in the distal basilar supply zones.
在颈动脉疾病（CAD）中，基底动脉（BA）可能作为重要的颅内侧支循环，为灌注不足的大脑中动脉（MCA）区域供血。进行经颅多普勒研究，以探讨BA血流动力学与MCA灌注状态之间的相关性。对40例因进展性CAD导致MCA进行性灌注不足的患者，评估了BA和MCA的血流速度（BFV）、搏动指数（API）和脑血管反应性（CVR）。所有患者的椎动脉颈段通畅，椎动脉血流呈顺行性。采用双功超声检查诊断CAD的严重程度。通过Diamox试验评估血管麻痹程度来诊断MCA灌注不足。分析表明，在进展性CAD患者中，基底动脉BFV显著增加，基底动脉PI降低，但基底动脉CVR保持不变。然而，在双侧血流动力学显著CAD且MCA区域双侧CVR耗竭的情况下，基底动脉BFV未增加，基底动脉PI也未降低，但基底动脉CVR显著降低。如果基底动脉在CAD中作为颅内侧支循环发挥作用，其CVR不会受损。然而，在双侧MCA区域灌注不足的情况下，基底动脉不能作为侧支循环通路。在这种情况下，基底动脉CVR下降，这仅仅反映了前后交界区血流动力学的耗竭。这种情况可能会增加基底动脉远端供血区的中风风险。
