Transcranial Doppler ultrasonographic evaluation of vertebral artery hypoplasia and focal artery stenosis / 国际脑血管病杂志

Objective To investigate the diagnostic values of transcranial Doppler ultrasonography (TCD) for vertebral artery hypoplasia (VAH) and focal vertebral artery stenosis (fVAS) with CT angiography (CTA) finding as a standard.Methods Consecutive patient who underwent TCD and CTA were included.According to the findings of CTA,they were divided into 3 groups:a normal group,a VAH group,and a fVAS group.The TCD parameters included the mean flow velocity (MFV),peak systolic velocity (PSV),pulsatility index (PI),resistance index (RI) and asymmetry index (AI),and they were compared among the groups,respectively.The receiver operator characteristic (ROC) curves were used to evaluate the sensitivity and specificity of TCD parameters for diagnosis of VAH and fVAS.Results A total of 405 patients were enrolled,including 278 (68.6％) in the normal group,75 (18.5％) in the VAH group,and 52 (12.8％) in the fVAS group.There were significant differences in MFV,PSV,PI,and RI on the affected sides among different groups (the affected side in the normal group was defined as the right side).The blood flow velocity in the VAH group was the slowest,and that in the fVAS group was the fastest.Other parameters had the same trend.There were significant differences in MFV and PSV on the unaffected side among different groups.The blood flow velocity in the VAH group was significantly faster,the fVAS group was slightly faster,and the fVAS group was less than the VAH group.There were significant differences in AI among different groups,and it could be used as an indicator for diagnosis of VAH (the area under the curve 0.78,95％ confidence interval 0.72-0.84;P＜0.001).With the AI ＞33.7％ as a cut-off value,the sensitivity and specificity of VAH diagnosis were 74.7％ and 68.7％.Conclusions Attention should be paid to identifying VAH and fVAS when using TCD for evaluation of vertebral artery.AI ＞33.7％ can be used as a reference index for diagnosis of VAH.

Vertebral artery hypoplasia and posterior circulation ischemic stroke / 国际脑血管病杂志

Vertebral artery hypoplasia is a frequent variation type of vertebral arteries.At present,there is no unified theory about the relationship between vertebral artery hypoplasia and posterior circulation ischemic stroke.The available evidence suggests that vertebral artery hypoplasia may be a precipitating factor for posterior circulation ischemic stroke; particularly other vascular risk factors coexist.This article elaborates the epidemiology of vertebral artery hypoplasia,the clinical manifestation and imaging features of vertebral artery hypoplasia in patients with posterior circulation ischemic stroke,and the possible mechanism of vertebral artery hypoplasia caused posterior circulation ischemic stroke.