Danish Headache Center, Glostrup Hospital, University of Copenhagen , Glostrup , Denmark.
Stroke Unit, Department of Neurology, Glostrup Hospital, University of Copenhagen , Glostrup , Denmark.
Front Neurol. 2013 Dec 16;4:204. doi: 10.3389/fneur.2013.00204. eCollection 2013.
Analysis of cerebral autoregulation by measuring spontaneous oscillations in the low frequency spectrum of cerebral cortical vessels might be a useful tool for assessing risk and investigating different treatment strategies in carotid artery disease and stroke. Near infrared spectroscopy (NIRS) is a non-invasive optical method to investigate regional changes in oxygenated (oxyHb) and deoxygenated hemoglobin (deoxyHb) in the outermost layers of the cerebral cortex. In the present study we examined oxyHb low frequency oscillations, believed to reflect cortical cerebral autoregulation, in 16 patients with both symptomatic carotid occlusive disease and cerebral hypoperfusion in comparison to healthy controls. Each hemisphere was examined with two NIRS channels using a 3 cm source detector distance. Arterial blood pressure (ABP) was measured via a finger plethysmograph. Using transfer function analysis ABP-oxyHb phase shift and gain as well as inter-hemispheric phase shift and amplitude ratio were assessed. We found that inter-hemispheric amplitude ratio was significantly altered in hypoperfusion patients compared to healthy controls (P = 0.010), because of relatively lower amplitude on the hypoperfusion side. The inter-hemispheric phase shift showed a trend (P = 0.061) toward increased phase shift in hypoperfusion patients compared to controls. We found no statistical difference between hemispheres in hypoperfusion patients for phase shift or gain values. There were no differences between the hypoperfusion side and controls for phase shift or gain values. These preliminary results suggest an impairment of autoregulation in hypoperfusion patients at the cortical level detected by NIRS.
通过测量大脑皮质血管低频谱中的自发性波动来分析脑自动调节，可能是评估颈动脉疾病和中风风险以及研究不同治疗策略的有用工具。近红外光谱（NIRS）是一种非侵入性的光学方法，用于研究大脑皮质最外层氧合（oxyHb）和去氧血红蛋白（deoxyHb）的区域变化。在本研究中，我们检查了 16 例有症状的颈动脉闭塞性疾病和脑灌注不足的患者与健康对照组之间，被认为反映皮质脑自动调节的 oxyHb 低频波动。每个半球使用两个 NIRS 通道，源探测器距离为 3cm。通过手指容积描记法测量动脉血压（ABP）。使用传递函数分析评估 ABP-oxyHb 相移和增益以及半球间相移和幅度比。我们发现，与健康对照组相比，灌注不足患者的半球间幅度比明显改变（P=0.010），因为灌注不足侧的幅度相对较低。与对照组相比，灌注不足患者的半球间相位偏移显示出增加的趋势（P=0.061）。我们发现灌注不足患者的相位偏移或增益值在两个半球之间没有统计学差异。灌注不足侧与对照组的相位偏移或增益值无差异。这些初步结果表明，NIRS 检测到皮质水平的灌注不足患者的自动调节受损。
