Study on the Correlation between different Levels of Patients with Vertebrobasilar Dolichoectasia and Posterior...

This study investigates the differences and changing trend of posterior circulation blood perfusion between different levels of vertebrobasilar dolichoectasia(VBD) patients. The relationship between the deviation of the basilar artery(BA) in different directions and the location of pontine infarction are also investigated.

A cohort of 106 patients(74 males and 32 females) who satisfied the diagnostic criteria for VBD were recruited for this study and classified according to the bifurcation height and the deviation position of the BA, as well as the measured blood perfusion value of the pontine, which includes rCBF, rCBV, MTT, and TTP.

Out of the 106 patients, 19 cases were classified as Level 1, 74 cases were classified as Level 2, and 13 cases were classified as Level 3. The different levels between the VBD groups were statistically significant (P<0.05, P<0.01), and it was found that as the level increases, rCBF and rCBV gradually decreased, while MTT and TTP gradually increased. The statistic results of different perfusion parameters were also significant, when pairwise comparisons between Level 1 and Level 3, and Level 2 and Level 3 were performed. However, when comparing Level 1 and Level 2, only the TTP showed significant result. Among 106 patients, 22 cases had brainstem infarction, 13 cases had left brainstem infarction, 8 cases had right brainstem infarction, and 1 case had brainstem infarction on both sides. Brainstem infarction generally occurs on the opposite side of the direction of BA deviation(P<0.05). Regardless of the BA was deviated to the left or right, perfusion analysis showed that there was significant difference in blood perfusion on both sides of the pontine when BA is deviated(P<0.05, P<0.01). The rCBF and rCBV on the contralateral side of deviation were lower than those on the same side, and the MTT and TTP were longer than those on the same side. There were 37 cases with vertebral artery dominance(VAD), 16 cases with left VAD, and 21 cases with right VAD. Statistical analysis showed that BA was more likely to deflect to the opposite side of the dominant artery(P<0.05), and compared with non-VAD, there was no significant difference in pontine blood perfusion (p>0.05).

As VBD level increases, rCBF and rCBV will gradually decreases while MTT and TTP showed sign of increasing. The location of brainstem infarction is opposite to the direction of the BA deviation, and BA is more likely to deviate to the opposite side of the dominant artery.