Evaluation of cerebral blood flow and cerebrovascular reactivity in Ischemic Stroke Patients Using Transcranial Doppler

다국어 초록 (Multilingual Abstract)

<Background and Purpose>
The assessment of cerebrovascular reactivity(CVR) provides information on the reserve capacity of cerebral circulation in patients with cerebrovascular disease. It also seems to be of prognostic relevance for patients with occlusive cerebrovascular disease. To estimate the CVR, we used a breath-holding maneuver with a transcranial doppler(TCD). So, we studied whether or not the blood flow and CVR could show differences between normal and ischemic stroke groups.

<Methods>
Using TCD, we measured mean velocities and a side-to-side difference (asymmetry index, Al) at a resting state in 43 normal and 65 ischemic stroke groups, diagnosed by brain CT or MRI. And CVR was estimated by the increase of middle cerebral artery mean blood velocity using a breath-holding maneuver. We calculated each breath holding indexes(BHI) in both the normal and patient groups. So, we estimated theh change of BHI by age in the normal group and compared the differences between symptomatic and asymptomatic hemispheres in the patient group.

<Results>
The BHI was 1.12±0.33 in normal group. There was no significant difference by age and no side-to-side differences. But BHI in the symptomatic hemisphere was significantly lower than the asymptomatic hemisphere in the ischemic stroke group(P<0.05). As for AI, the patient's group showed lower values than the normal group in middle(MCA), anterior(ACA) and posterior cerebral artery(PCA). Especially, there was a significant difference between theh normal and patient groups in the middle cerebral artery(P<0.05). But, mean velocities showed no significant differences between the symptomatic and asymptomatic hemispheres in MCA, ACA and PCA.

<Conclusion>
Using TCD, a breath holding method could be a useful method in the estimation of the CVR, and BHI could be applied in the basal and follow-up study of CVR of the ischemic stroke patients. So we suggest that the study of BHI may provide a useful information for the understanding of hemodynamic status and prognosis in ischemic stroke.