Relation Between Vertebrobasilar Dolichoectasia And Cerebral Microbleeds

Objective: To analyze the relationship between vertebrobasilar dolichoectasia(VBD) and cerebral microbleeds(CMBs) in patients with acute cerebral infarction.Methods: Three hundred and three patients with acute cerebral infarction,admitted to our hospitals from June 2013 to January 2015,were chosen in our study;MR imagings,including T1 WI,T2WI,fluid-attenuated inversion recovery sequence(FLAIR), diffusion weighted imaging(DWI), magnetic resonance angiography(MRA)and susceptibility weighted imaging(SWI),were performed in all the patients.All patients accepted related blood biochemical tests. The basic clinical data, including gender,age,family history of stroke, histories of smoking,alcohol consumption,ischemic heart disease, hypertension and diabetes,and levels of cholesterol(CHOL),triglyceride(TG),high density lipoprotein(HDL),low density lipoprotein(LDL) and plasma homocysteine(Hcy),were collected. Ectasia was defined as basilar artery(BA)diameter>4.5 mm, and dolichosis, as either BA bifurcation above the suprasellar cistern or lateral to the margin of the clivus or dorsum sellae. The patients were divided into two groups respectively according to the results of MR imagings, CMB group and non-CMB group, VBD group and non-VBD group. CMB locations were categorized into anterior and posterior circulation. The numbers of MB were counted in anterior and posterior circulation territory. Whether VBD is associated with CMB anywhere in the brain or in anterior or posterior circulation territories was analysed using binary and multinomial logistic regression models.Results:1.Of the 303 acute cerebral infarction patients, VBD was found in27(8.9%).Cerebral microbleeds were detected in 116 patients(38.3%). 23 patients(7.6%)had CMBs only in the anterior circulation territory, 17(5.6%) had CMBs only in the posterior circulation territory, and 76(25.1%) had CMBs in both territories.2.Comparison of the distribution of CMBs according to the presence of VBD.Compared with non-VBD group, number of CMBs in the posterior territory(Z=-3.760,P=0.000), number of CMBs in any location(Z=-2.819,P=0.005), frequency of patients with CMBs in the posterior territory(χ2=11.371,P=0.002) and frequency of patients with CMBs in any location(χ2=7.641,P=0.007) in the patients with VBD had statistical difference.But number of CMBs in the anterior territory(Z=-1.053, P=0.292) and frequency of patients with CMBs in the anterior territory(χ2=1.867,P=0.198) did not significantly differ by VBD presence.3.Single factor analysis to investigate the related factors of CMBs presence showed that age(t =-2.066, P=0.040), hypertension(χ2=5.539, P=0.024),leukoaraiosis(χ2=17.949,P=0.000) and VBD(χ2=7.641,P=0.007) in the patients with CMB had statistical difference. Age, hypertension, leukoaraiosis and VBD were associated with the presence of CMBs. The binary logistic regression analysis showed that VBD(OR=2.704;95% CI,1.137~6.431;P =0.024) was significantly associated with CMBs in any location even after adjustment for age, hypertension and leukoaraiosis.4.Multinomial logistic regression analyses to investigate the contribution of VBD to CMB presence and location showed that although VBD was not statistically associated with the presence of CMBs in the anterior circulation territory only(crude OR=1.243, 95% CI, 0.152~10.179; P=0.839), it was significantly associated with the presence of CMBs in the posterior circulation territory only(crude OR=0.136,95%CI,0.040 ~ 0.460; P=0.001) as well as with CBMs in both territories(crude OR=0.334,95%CI,0.135~0.823;P=0.017). The significant relationship of VBD with the presence of CMBs in the posterior circulation territory only(adjusted OR=0.146,95%CI,0.040~0.530;P=0.003) was maintained even after adjustment for age, gender,hypertension and leukoaraiosis;whereas in both territories(adjusted OR= 0.399,95%CI,0.151~1.058;P = 0.065) did not significantly differ.Conclusion:1. In the patients with acute cerebral infarction, cerebral microbleeds were more frequently observed and were more numerous in patients with VBD than in patients without VBD, CMBs in patients with VBD were more likely to be located in the posterior circulation territory.2.VBD in patients with acute cerebral infarction is independently associated with CMBs, especially in the posterior circulation territory.