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Vertebral artery dominance contributes to basilar artery curvature and peri-vertebrobasilar junctional infarcts.

Hong JM, Chung CS, Bang OY, Yong SW, Joo IS, Huh K - J. Neurol. Neurosurg. Psychiatr. (2009)

Bottom Line: The dominant VA was more frequent on the left side (p<0.01).Most patients had an opposite directional relationship between the dominant VA and BA curvature (p<0.01).The difference in VA diameters was the single independent predictor for moderate to severe BA curvature (OR per 1 mm, 2.70; 95% CI 1.22 to 5.98).

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Ajou University Medical Centre, Ajou University School of Medicine, Yongtong-Gu, Suwon-Si, Kyunggi-Do, South Korea. dacda@hanmail.net

ABSTRACT

Objectives: The diameters of the vertebral arteries (VAs) are very often unequal. Therefore, this study investigated if unequal VA flow contributes to the development of basilar artery (BA) curvature and if it is a link to the laterality of pontine or cerebellar infarcts occurring around the vertebrobasilar junction.

Methods: Radiological factors were analysed (infarct laterality, VA dominance, BA curvature and their directional relationships) in 91 patients with acute unilateral pontine or posterior inferior cerebellar artery (PICA) territory infarcts. The "dominant" VA side was defined as either that the VA was larger in diameter or the VA was connected with the BA in more of a straight line, if both VAs looked similar in diameter on CT angiography. Multiple regression analysis was performed to predict moderate to severe BA curvature.

Results: The dominant VA was more frequent on the left side (p<0.01). Most patients had an opposite directional relationship between the dominant VA and BA curvature (p<0.01). Pontine infarcts were opposite to the side of BA curvature (p<0.01) and PICA infarcts were on the same side as the non-dominant VA side (p<0.01). The difference in VA diameters was the single independent predictor for moderate to severe BA curvature (OR per 1 mm, 2.70; 95% CI 1.22 to 5.98).

Conclusions: Unequal VA flow is an important haemodynamic contributor of BA curvature and development of peri-vertebrobasilar junctional infarcts.

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Schematic illustrations of the pathophysiological process of peri-vertebral junctional infarcts: possible changes in vetebrobasilar vessels under the condition of an unequal VA flow. BA, basilar artery, VA, vertebral artery.
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JNN-80-10-1087-f03: Schematic illustrations of the pathophysiological process of peri-vertebral junctional infarcts: possible changes in vetebrobasilar vessels under the condition of an unequal VA flow. BA, basilar artery, VA, vertebral artery.

Mentions: Such directional relationships can be explained by several haemodynamic mechanisms. Firstly, the inner wall of the BA curvature may be more thrombogenic because of a low WSS,4 24 and traction of the pontine perforators caused by BA curvature may lead to infarction.20 Secondly, a hypoplastic VA can cause ipsilateral PICA infarction by directly decreasing blood flow in the smaller intracranial VA.24 This can occur because of the easy collapsibility of a narrowed vessel as a result of Bernoulli’s effect under the decreased VA remodelling capacity.25 Our theory is outlined in fig 3. The vector of BA flow merging from unequal VAs makes the BA flow curve to the side of the weaker VA, and the chronic processes caused by asymmetric VA flow can induce greater curving of the BA wall. Subsequently, such deformation of the BA can cause atherogenesis, leading to ischaemic stroke in the vertebrobasilar system. A hypoplastic VA can also result in the ipsilateral occlusion of this vessel due to a direct decrease in blood flow and easy collapse of the vessel caused by the smaller intracranial VA calibre.


Vertebral artery dominance contributes to basilar artery curvature and peri-vertebrobasilar junctional infarcts.

Hong JM, Chung CS, Bang OY, Yong SW, Joo IS, Huh K - J. Neurol. Neurosurg. Psychiatr. (2009)

Schematic illustrations of the pathophysiological process of peri-vertebral junctional infarcts: possible changes in vetebrobasilar vessels under the condition of an unequal VA flow. BA, basilar artery, VA, vertebral artery.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2735647&req=5

JNN-80-10-1087-f03: Schematic illustrations of the pathophysiological process of peri-vertebral junctional infarcts: possible changes in vetebrobasilar vessels under the condition of an unequal VA flow. BA, basilar artery, VA, vertebral artery.
Mentions: Such directional relationships can be explained by several haemodynamic mechanisms. Firstly, the inner wall of the BA curvature may be more thrombogenic because of a low WSS,4 24 and traction of the pontine perforators caused by BA curvature may lead to infarction.20 Secondly, a hypoplastic VA can cause ipsilateral PICA infarction by directly decreasing blood flow in the smaller intracranial VA.24 This can occur because of the easy collapsibility of a narrowed vessel as a result of Bernoulli’s effect under the decreased VA remodelling capacity.25 Our theory is outlined in fig 3. The vector of BA flow merging from unequal VAs makes the BA flow curve to the side of the weaker VA, and the chronic processes caused by asymmetric VA flow can induce greater curving of the BA wall. Subsequently, such deformation of the BA can cause atherogenesis, leading to ischaemic stroke in the vertebrobasilar system. A hypoplastic VA can also result in the ipsilateral occlusion of this vessel due to a direct decrease in blood flow and easy collapse of the vessel caused by the smaller intracranial VA calibre.

Bottom Line: The dominant VA was more frequent on the left side (p<0.01).Most patients had an opposite directional relationship between the dominant VA and BA curvature (p<0.01).The difference in VA diameters was the single independent predictor for moderate to severe BA curvature (OR per 1 mm, 2.70; 95% CI 1.22 to 5.98).

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Ajou University Medical Centre, Ajou University School of Medicine, Yongtong-Gu, Suwon-Si, Kyunggi-Do, South Korea. dacda@hanmail.net

ABSTRACT

Objectives: The diameters of the vertebral arteries (VAs) are very often unequal. Therefore, this study investigated if unequal VA flow contributes to the development of basilar artery (BA) curvature and if it is a link to the laterality of pontine or cerebellar infarcts occurring around the vertebrobasilar junction.

Methods: Radiological factors were analysed (infarct laterality, VA dominance, BA curvature and their directional relationships) in 91 patients with acute unilateral pontine or posterior inferior cerebellar artery (PICA) territory infarcts. The "dominant" VA side was defined as either that the VA was larger in diameter or the VA was connected with the BA in more of a straight line, if both VAs looked similar in diameter on CT angiography. Multiple regression analysis was performed to predict moderate to severe BA curvature.

Results: The dominant VA was more frequent on the left side (p<0.01). Most patients had an opposite directional relationship between the dominant VA and BA curvature (p<0.01). Pontine infarcts were opposite to the side of BA curvature (p<0.01) and PICA infarcts were on the same side as the non-dominant VA side (p<0.01). The difference in VA diameters was the single independent predictor for moderate to severe BA curvature (OR per 1 mm, 2.70; 95% CI 1.22 to 5.98).

Conclusions: Unequal VA flow is an important haemodynamic contributor of BA curvature and development of peri-vertebrobasilar junctional infarcts.

Show MeSH
Related in: MedlinePlus