Mitchell Jeanette
Department of Zoology and Physiology, School of Biological Sciences, University of Wyoming, Laramie, WY 82071, USA.
Physiother Res Int. 2008 Mar;13(1):53-66. doi: 10.1002/pri.370.
The atlanto-axial region of the vertebral artery (VA) has traditionally been considered at risk for injury during cervical spine rotation, leading to compromised blood flow to the hindbrain and vertebrobasilar insufficiency or ischaemia (VBI). The anatomical relationships of the suboccipital VA (VA3) and related haemodynamic changes associated with cervical spine movements have been neglected, however. The present review aims to provide a new perspective on possible causes of reduced blood flow to the hindbrain, with particular reference to the functional anatomy of VA3 and related biomechanics of cervical spine rotation, to inform evidence-based practice.
To support the hypothesis that it is VA3, not the VA in the atlanto-axial region, that is compressed or stretched during cervical spine rotation, current studies of blood flow changes in the VA distal to the region of rotation and possible arterial deformation were retrieved, using AMED, CINAHL, Embase, Pedro and PubMed, and reviewed.
Possible sites for VA3 deformation, based on a re-examination of its anatomy and biomechanics, are described. However, no research reports of VA3 blood flow measurements associated with cervical spine rotation have been published to date. Five studies on blood flow changes in the intracranial VA after cervical spine rotation were reviewed. The subjects for four of these reports were young, healthy individuals, and the fifth included older patients and young non-patients. The analysis of these studies demonstrated that more rigorous control of variables is necessary before meaningful conclusions can be made.
The paucity of studies of VA3 emphasises the need for research based on informed understanding of the anatomy and biomechanics of this area. This view on mechanical deformation of VA3 associated with cervical spine rotation as a possible cause of compromised blood flow to the hindbrain and VBI provides further argument for avoiding full-range or sustained cervical spine rotation in clinical practice.
传统上认为颈椎旋转时椎动脉（VA）寰枢段有受伤风险，会导致后脑血流受损及椎基底动脉供血不足或缺血（VBI）。然而，枕下椎动脉（VA3）的解剖关系以及与颈椎运动相关的血流动力学变化一直被忽视。本综述旨在提供关于后脑血流减少可能原因的新观点，特别参考VA3的功能解剖及颈椎旋转相关生物力学，为循证实践提供依据。
为支持颈椎旋转时受压或拉伸的是VA3而非寰枢段椎动脉这一假说，检索了AMED、CINAHL、Embase、Pedro和PubMed数据库中关于旋转区域远端椎动脉血流变化及可能的动脉变形的现有研究并进行综述。
基于对VA3解剖和生物力学的重新审视，描述了其可能的变形部位。然而，目前尚无关于颈椎旋转时VA3血流测量的研究报告发表。综述了五项关于颈椎旋转后颅内椎动脉血流变化的研究。其中四项报告的研究对象为年轻健康个体，第五项研究包括老年患者和年轻非患者。对这些研究的分析表明，在得出有意义的结论之前，需要更严格地控制变量。
对VA3的研究匮乏凸显了基于对该区域解剖和生物力学深入理解进行研究的必要性。将与颈椎旋转相关的VA3机械变形视为后脑血流受损和VBI的可能原因这一观点，为临床实践中避免颈椎全范围或持续旋转提供了进一步的依据。
