Eicke Bernhard M, Milke Kai, Schlereth Tanja, Birklein Frank
Dept. of Neurology, University Clinic of Mainz, Langenbeckstr. 1, 55101 Mainz, Germany.
J Neurol. 2004 Aug;251(8):958-62. doi: 10.1007/s00415-004-0471-7.
Laser Doppler is widely used to evaluate sympathetic vasoconstrictor function. Continuous wave (cw)-Doppler of the radial artery may be an alternative but less expensive approach to quantify sympathetically induced resistance changes in the peripheral vascular system. In order to compare the power of both methods, this study was performed with simultaneous assessment of cw Doppler and laser Doppler flowmetry in volunteers. Twenty-five healthy subjects (median age years, range 20-27) rested in a relaxed supine position and were asked to perform a deep inspiratory gasp and a commanded cough (DIG + C). Radial artery blood flow was assessed with a standard cw Doppler device, arteriolar blood flow was assessed simultaneously employing a single point laser Doppler perfusion monitor at the fingertips. We quantified the latency between stimulus and onset of vasoconstriction, the latency to the maximum vasoconstriction and the duration of response. The decrease in flow velocities (cw Doppler) after stimulus was compared with the decrease in capillary flow (laser Doppler). While the flow profile as measured with laser Doppler remained monophasic after stimulation, cw Doppler showed biphasic flow (or absent diastolic flow) in all subjects after DIG + C. The latencies between stimulus and onset of reaction were significantly shorter when measured with laser Doppler (1.8 s vs. 2 s, p = 0.049), the latencies till the maximum extent of the reaction was reached did not differ significantly (3.2 vs. 3.3 s). The duration of the response was significantly shorter when measured by laser Doppler (12.0 vs. 14.5 s (p < 0.0001). While skin blood flow in the laser Doppler measurement decreased after stimulation from 654 flux units (FU) to 319 FU (-59%), mean flow velocities in the radial artery declined from 1.07 kHz to 0.14 kHz (-87%). This relative change was significantly different (p < 0.0001). The correlation between the decline of flux units as measured by laser Doppler and cw Doppler changes was r = 0.616 (p = 0.004). Both methods are feasible to monitor flow changes due to sympathetic stimulation. Latencies and relative quantitative changes were closely correlated.Thus, cw Doppler is a valid alternative approach to laser Doppler flowmetry in healthy volunteers.
激光多普勒广泛用于评估交感神经血管收缩功能。桡动脉连续波（cw）多普勒可能是一种替代方法，且成本较低，可用于量化外周血管系统中交感神经诱导的阻力变化。为比较这两种方法的效能，本研究对志愿者同时进行cw多普勒和激光多普勒血流仪评估。25名健康受试者（年龄中位数为岁，范围20 - 27岁）以放松的仰卧姿势休息，并被要求进行深吸气屏气和指令性咳嗽（DIG + C）。用标准cw多普勒设备评估桡动脉血流，同时在指尖使用单点激光多普勒灌注监测仪评估小动脉血流。我们量化了刺激与血管收缩开始之间的延迟、最大血管收缩的延迟以及反应持续时间。将刺激后流速的降低（cw多普勒）与毛细血管血流的降低（激光多普勒）进行比较。激光多普勒测量的血流曲线在刺激后仍保持单相，而在DIG + C后，所有受试者的cw多普勒均显示双相血流（或舒张期血流缺失）。用激光多普勒测量时，刺激与反应开始之间的延迟明显更短（1.8秒对2秒，p = 0.049），达到反应最大程度的延迟无显著差异（3.2对3.3秒）。激光多普勒测量的反应持续时间明显更短（12.0对14.5秒（p < .0001）。激光多普勒测量中，刺激后皮肤血流从654通量单位（FU）降至319 FU（-59%），而桡动脉平均流速从1.07千赫兹降至0.14千赫兹（-87%）。这种相对变化有显著差异（p < .0001）。激光多普勒测量的通量单位下降与cw多普勒变化之间的相关性为r = 0.616（p = 0.004）。两种方法都可用于监测交感神经刺激引起的血流变化。延迟和相对定量变化密切相关。因此，在健康志愿者中，cw多普勒是激光多普勒血流仪的一种有效替代方法。
