The Study On The Characteristics Of Dynamic Cerebral Autoregulation In Patients With Anterior Circulation Cerebral Vascular Stenosis

Objective:Previous studies have shown that stenosis of internal carotid artery(ICA)or middle cerebral artery(MCA)could comprise dynamic cerebral autoregulation(dCA)which increased stroke risk.And the degree of stenosis was also revealed to be related with changes in autoregulatory capability while the stenosis on various arteries might pose different impact on dCA.We conducted this study to 1)analyze dCA in patients with anterior circulation cerebral vascular stenosis and to 2)explore the difference of dCA between ICA and MCA.Methods:Data of cerebral autoregulation was documented in 174 patients with unilateral ICA or MCA severe stenosis or occlusion and 60 healthy controls.Blood flow velocity was continuously monitored by transcranial doppler sonography of the middle cerebral artery,and data of blood pressure was collected by non-invasive fingertip monitor simultaneously.Dynamic cerebral autoregulation parameters:very low phase(VL phase),low phase(Low phase)and rate of recovery of cerebral blood flow velocity(ROR of CBFV)were calculated from the measured data.Results:Compared with the healthy control group,dynamic cerebral autoregulation of symptomatic severe stenosis or occlusion group was impaired bilaterally(P<0.05).And patients with unilateral severe stenosis or occlusion demonstrated significant reduction(P<0.05)in VL phase、Low phase and ROR of CBFV on the ipsilateral side of the affected vessel compared with the contralateral side.The VL phase values、Low phase values and ROR of CBFV values in ICA group were all significantly lower(P<0.05)than that in MCA group on the ipsilateral side of the affected vessel.And after adjusting related factors,the VL phase values were still significantly lower(β=232,P<0.001)in ICA group.Conclusion:This study suggested that dCA was impaired globally in patients with ipsilateral severe stenosis or occlusion of MCA and ICA,especially on the same side of the affected vessel.Patients with ICA severe stenosis or occlusion had worse dCA than that of patients with MCA severe stenosis or occlusion on the ipsilateral side of the affected vessel.