植物状态,闭锁综合征和脑死亡的经颅多普勒超声检查

目的：比较植物状态（ＰＶＳ）、闭锁综合征和脑死亡患者脑血流的特点。方法：用经颅多普勒超声（ＴＣＤ）检测ＰＶＳ、闭锁综合征和脑死亡患者双侧大脑中动脉（ＭＣＡ）和基底动脉（ＢＡ）的血流情况。结果：持续植物状态ＭＣＡ和ＢＡ的平均血流速分别为２９．０ｃｍ／ｓ和２３．３ｃｍ／ｓ，较正常下降４７％和２２．３％。闭锁综合征ＭＣＡ和ＢＡ的平均血流速分别为４８．０ｃｍ／ｓ和１０．３ｃｍ／ｓ，分别较正常下降８．２％和６０．０％。提示ＰＶＳ的血流速减慢以前循环为主，而闭锁综合征的血流速减慢以后循环为主。脑死亡则为特殊的双向血流、收缩期短小尖波或无血流信号，与ＰＶＳ或闭锁综合征患者的ＴＣＤ完全不同。结论：根据前后循环血流速减慢的不同及特殊的脑血流频谱，ＴＣＤ能帮助医师鉴别上述三种临床上有时易混淆的状态

TCD in Persistent Vegetative Status,Locked in Syndrome and Brain Death

Purpose:TCD characteristiscs of cerebral circulation in persistent vegetative status(PVS),locked in syndrome and brain dead patients were compared.Method:Transcranial Doppler ultrasound studies of the flow velocity and waveform patterns of middle cerebral artery(MCA)and basilar artery(BA)were engaged.Results:The mean velocity of middle cerebral artery(Vmca)and basilar artery(Vba)were 29cm/s and 23 3cm/s in PVS patients respectively.The velocity decreased 47% and 22 3% compared with control group.For locked in patients.Vmca and Vba were 48cm/s and 10 3cm/s.It decreased 8 2% and 60%.This results showed that the decrease of anterior circulation greater than that of posterior circulation in PVS.However,the decrease of posterior circulation was greater than anterior circulation in locked in syndrome.There are three specific patterns in brain dead patients:oscillation flow,shot systolic peak and no flow.Conclusion:TCD was valuable in distinguishing PVS,locked in syndrome and brain dead patients according to their different velocities and patterns of anterior and posterior arteries.