Hartmann A, Mast H, Thompson J L, Sia R M, Mohr J P
Stroke Unit, The Neurological Institute, Columbia-Presbyterian Medical Center, New York, NY 10032, USA.
Cerebrovasc Dis. 2000 Jan-Feb;10(1):33-8. doi: 10.1159/000016022.
To investigate the frequency of transcranial Doppler (TCD) waveform blunting in patients with severe (80-99%) symptomatic or asymptomatic extracranial carotid artery stenosis.
Severe carotid artery stenosis has been identified as a risk factor for ischemic stroke. Blunted Doppler flow waveforms (reduced systolic flow velocity and pulsatility) of the middle cerebral artery (MCA) are inferred to reflect hemodynamic impairment, possibly indicating an increased risk of stroke.
The 114 consecutive patients (mean age 72.4 years, SD 9.0 years; 37% women; 46 clinically symptomatic, 68 asymptomatic) with 80-99% stenosis of the extracranial internal carotid artery (ICA), as determined by duplex sonography, were examined with TCD. Flow velocities, pulsatility index, and spectral waveforms of the MCA distal to the ICA stenosis were assessed blinded to the clinical status of the ICA: Doppler waveform blunting was defined as loss of the characteristic systolic peak. Odds ratios with 95% confidence intervals and chi(2) statistics were used to describe the association between waveform blunting and the symptomatic status of the ICA stenosis.
Among symptomatic patients, 23 (50%) had completed strokes, and a further 23 (50%) had transient neurologic deficits in the territory of the stenotic ICA. Blunted spectral waveform was found in 37 (80%, 95% CI 68-92%) of the symptomatic and 25 (37%; 95% CI 25-49%) of the asymptomatic patients. Symptomatic patients had significantly increased odds of having blunted TCD waveforms (OR 7.5, 95% CI 3.1-18.1, p < 0.001).
Our findings suggest that TCD waveform blunting in the MCA as here described may be an additional risk factor in the setting of severe extracranial carotid artery stenosis. A prospectively designed study to confirm our results seems warranted.
探讨重度（80 - 99%）有症状或无症状颅外颈动脉狭窄患者经颅多普勒（TCD）波形变钝的频率。
重度颈动脉狭窄已被确定为缺血性卒中的危险因素。大脑中动脉（MCA）多普勒血流波形变钝（收缩期血流速度和搏动性降低）被推断反映血流动力学损害，可能提示卒中风险增加。
对114例经双功超声检查确定颅外颈内动脉（ICA）狭窄80 - 99%的连续患者（平均年龄72.4岁，标准差9.0岁；37%为女性；46例有临床症状，68例无症状）进行TCD检查。在不了解ICA临床状况的情况下，评估ICA狭窄远端MCA的血流速度、搏动指数和频谱波形：多普勒波形变钝定义为特征性收缩峰消失。采用95%置信区间的比值比和卡方统计量来描述波形变钝与ICA狭窄症状状态之间的关联。
在有症状的患者中，23例（50%）有过卒中，另外23例（50%）在狭窄ICA供血区域有短暂神经功能缺损。有症状患者中37例（80%，95%置信区间68 - 92%）出现频谱波形变钝，无症状患者中25例（37%；95%置信区间25 - 49%）出现频谱波形变钝。有症状患者TCD波形变钝的几率显著增加（比值比7.5，95%置信区间3.1 - 18.1，p < 0.001）。
我们的研究结果表明，本文所述的MCA中TCD波形变钝可能是重度颅外颈动脉狭窄情况下的一个额外危险因素。一项前瞻性设计的研究以证实我们的结果似乎是必要的。
