OBJECTIVE: To probe into the effects of modified Banxia Baizhu Tianma decoction on calcitonin gene-related peptide（CGRP）

endothelin-1（ET-1）

blood viscosity and cerebral blood flow velocity in patients with posterior circulation ischemic vertigo（phlegm stasis and blocking collaterals type）. METHODS: Totally 126 patients with posterior circulation ischemic vertigo（phlegm stasis and blocking collaterals type） admitted into the hospital from May 2018 to Jun. 2021 were extracted to be divided into the observation group and the control group via the random number table

with 63 cases in each group. The control group received conventional western medicine treatment

while the observation group was treated with modified Banxia Baizhu Tianma decoction based on the control group. After 4 weeks of treatment

the clinical efficacy was compared. Changes of CGRP

superoxide dismutase（SOD） and ET-1 levels

improvement of hemorheology

and improvement of cerebral blood flow velocity [vertebrobasilar artery（BA）

left vertebral artery（LVA） and right vertebral artery（RVA）] before and after treatment were observed in two groups. The scores of Dizziness Handicap Inventory（DHI）

36-item Short Form Health Survey（SF-36） and Berg Balance Scale（BBS） were recorded. RESULTS: After treatment

the serum CGRP and SOD levels were higher

the ET-1 level was lower in the observation group than those in the control group

with statistically significant differences（P<0.05）. After treatment

the plasma viscosity

whole blood low shear viscosity and whole blood high shear viscosity of the observation group were lower than those of the control group

with statistically significant differences（P<0.05）. The cerebral blood flow velocity（BA

LVA and RVA） of the observation group were faster than those of the control group after treatment

with statistically significant differences（P<0.05）. After treatment

the DHI score was lower

the SF-36 and BBS scores were higher in the observation group than those in the control group

with statistically significant differences（P<0.05）. The total effective rate of observation group was 95.24%（60/63）

which was higher than that of the control group（77.78%

49/63）

with statistically significant difference（P<0.05）. CONCLUSIONS: The efficacy of conventional western medicine combined with modified Banxia Baizhu Tianma decoction in the treatment of patients with posterior circulation ischemic vertigo（phlegm stagnation and blocking collaterals type） is remarkable

which can regulate vascular endothelial function and hemodynamics

promote the recovery of cerebral blood supply

improve clinical efficacy.