Newell D W, Aaslid R, Stooss R, Reulen H J
Department of Neurological Surgery, University of Washington, Seattle.
J Neurosurg. 1992 Mar;76(3):415-21. doi: 10.3171/jns.1992.76.3.0415.
Intracranial pressure (ICP) and continuous transcranial Doppler ultrasound signals were monitored in 20 head-injured patients and simultaneous synchronous fluctuations of middle cerebral artery (MCA) velocity and B waves of the ICP were observed. Continuous simultaneous monitoring of MCA velocity, ICP, arterial blood pressure, and expired CO2 revealed that both velocity waves and B waves occurred despite a constant CO2 concentration in ventilated patients and were usually not accompanied by fluctuations in the arterial blood pressure. Additional recordings from the extracranial carotid artery during the ICP B waves revealed similar synchronous fluctuations in the velocity of this artery, strongly supporting the hypothesis that blood flow fluctuations produce the velocity waves. The ratio between ICP wave amplitude and velocity wave amplitude was highly correlated to the ICP (r = 0.81, p less than 0.001). Velocity waves of similar characteristics and frequency, but usually of shorter duration, were observed in seven of 10 normal subjects in whom MCA velocity was recorded for 1 hour. The findings in this report strongly suggest that B waves in the ICP are a secondary effect of vasomotor waves, producing cerebral blood flow fluctuations that become amplified in the ICP tracing, in states of reduced intracranial compliance.
对20例颅脑损伤患者进行了颅内压（ICP）和连续经颅多普勒超声信号监测，观察到大脑中动脉（MCA）血流速度与ICP的B波同时出现同步波动。对MCA血流速度、ICP、动脉血压和呼出二氧化碳进行连续同步监测发现，在通气患者二氧化碳浓度恒定的情况下，仍会出现速度波和B波，且通常不伴有动脉血压波动。在ICP的B波期间对颅外颈动脉进行的额外记录显示，该动脉的血流速度也有类似的同步波动，有力地支持了血流波动产生速度波这一假说。ICP波幅与速度波幅之比与ICP高度相关（r = 0.81，p < 0.001）。在记录了1小时MCA血流速度的10名正常受试者中，有7人观察到了特征和频率相似但持续时间通常较短的速度波。本报告中的研究结果强烈表明，ICP中的B波是血管舒缩波的继发效应，在颅内顺应性降低的状态下，它会产生脑血流波动，并在ICP描记图中被放大。
