The Clinical Value Of Transcranial Doppler Combined With Quantitative EEG In Patients With Unilateral Middle Cerebral Artery Severe Stenosis Or Occlusion

Occlusion or stenosis of the middle cerebral artery (MCA) is considered to be the most common vascular cause of stroke in Asian populations, no absolute parallel relationship can be found between MCA stenosis degree and clinical symptoms, it can clinically manifest as asymptomatic, mild symptoms or even massive cerebral infarction and other serious symptoms. So, how to deal with MCA stenosis in asymptomatic patients is crucial for clinicians. Domestic clinicians always use perfusion magnetic resonance imaging to evaluate whether asymptomatic MCA stenosis patients require further stent treatment, but PWI need injection of contrast medium, costly and difficult to carry out dynamic observation, if there is a non-invasive, convenient, economical technique to detection ischemia will be a big help to choose the right clinical treatment strategies. This study observed the clinical value of TCD combined with qEEG in patients with unilateral middle cerebral artery severe stenosis or occlusion, designed to provide convenient means to assess the patient’s condition, the decision of clinical treatment, the efficacy and prognosis of MCA stenosis patients.Methods:The74patients who were diagnosed of unilateral MCA severe stenosis or occlusion by TCD during from May2012to September2014in the department of Neurology of First Hospital of Norman Bethune were included in the patient group, which were divided into45cases of symptomatic and29cases of asymptomatic group.25normal volunteers who were exclude intracranial vascular lesions by TCD and color Dopple were selected as a control group. The nerve monitoring was used to detect the continuous EEG, TCD was used to detect the cerebral hemodynamics changes of MCA stenosis or occlusion, evaluate the degree of ACA-MCA or PCA-MCA leptomeningeal artery collateral circulation. Combined with head MRI, MRA, PWI imaging changes, the comparative analysis of the symptomatic group, asymptomatic group in brain function, collateral circulation, perfusion differences and the differences correlation with the occurrence of stroke, aimed to explore the clinical value of transcranial doppler combined with quantitative EEG in patients with unilateral middle cerebral artery severe stenosis or occlusion for condition assessment, treatment decisions, efficacy and clinical value of prognosis.Results:1. Comparison of relative band power of qEEG in three groups(1) Comparison of whole brain RBPs in three groups:the RBPs of δ,θ waves of symptomatic group were significantly higher than that of asymptomatic group and control group(P<0.05), RBPs of a wave were decreased significantly(P<0.05), The asymptomatic group only have RBPs of a wave significantly lower than that of control group(P<0.05), but RBPs of δ,θ waves had no significant statistical difference(P>0.05).(2) Comparison of RBPs on ipsilateral MCA regions in three groups:the RBPs of δ,θ waves on the ipsilateral MCA regions of symptomatic group were significantly higher than that of asymptomatic group and control group(P<0.05), RBPs of a wave on the ipsilateral MCA regions were decreased significanty(P＜0.05); The asymptomatic ipsilateral MCA regions only have RBPs of a wave significantly lower than that of control group(P<0.05), but RBPs of8,0waves had no significant statistical difference(P>0.05).(3) Comparison of RBPs on ipsilateral MCA regions with contralateral regions in three groups:The RBPs of δ waves on the ipsilateral MCA regions of symptomatic group were significantly higher than that on contralateral regions(t=3.91, P=0.000), RBPs of α, β waves on the ipsilateral MCA regions were decreased significantly(t=-2.99,P=0.005; s=-4.29, P=0.000); The ipsilateral MCA regions of asymptomatic group only have RBPs of8wave significantly higher than that of contralateral regions(t=2.08, P=0.048), RBPs of α, β waves had no significant statistical difference(.P=0.497; P=0.246), RBPs of all band waves had no significant difference in control group(P>0.05).(4) Comparison of RBPs on ipsilateral occipitalia with contralateral occipitalia in three groups:The RBPs of8waves on the ipsilateral occipitalia of symptomatic group were significantly higher than that on contralateral occipitalia(t=4.77,.P=0.000), RBPs of α,β waves on the ipsilateral occipitalia were decreased significantly(t=-3.58, P=0.001; s=-215.50, P=0.000); Bilateral asymmetry of RBPs of all the wave-band had no significant statistical difference in asymptomatic group and control group (P>0.05).(5) Comparison of RBPs contralateral occipitalia in three groups:the RBPs of8,0waves on the contralateral occipitalia of symptomatic group were significantly higher than that of control group(P<0.05), RBPs of a wave on the contralateral occipitalia were decreased significantly(P<0.05); The contralateral occipitalia of asymptomatic group The RBPs of δ wave on the contralateral occipitalia of asymptomatic group slightly higher than that of control group, the RBPs of a wave slightly lower than that of control group(P<0.05).(6)The correlation between qEEG parameters and NIHSS scores in symptomatic group:There was positive correlation between NIHSS scores and RBPs of8waves on the whole brain(r=0.83,.P=0.000), and negatively correlated with RBPs of α, β waves on the whole brain(r=-0.73, P=0.004; r=-0.64, P=0.019).2.Comparison of hemodynamic detected by TCD in three groups(1)Comparison of blood flow velocity in three groups:The velocity of systolic (Vs)of nvMCA, dvACA, nvACA, dvPCA, nvPCA in symptomatic group and asymptomatic group were significantly higher than that of control group(P<0.01); the Vs of dvACA, dvPCA in asymptomatic group were significantly higher than that of symptomatic group(P<0.05).(2) Comparison of collateral flow rate ratio in three groups:there were no significantly difference in Rvpca, dvACA/nvMCA, RVaca among three groups(P>0.05).(3) Comparison of collateral flow rate ratio in different degree of MCA stenosis group:The RVaca in occlusion group was significantly higher than that in severe stenosis group and control group(P<0.05).3. The correlation between qEEG parameters and PWI parameters(1)The correlation between RBPs and CBV, CBF:there were no significantly differences between CBV normal and abnormal group; the RBPs of8waves in CBF decreased group on MCA ipsilateral MCA regions and ipsilateral occipitalia were significantly higher than that of CBF normal group(F=6.36, P=0.033; F=8.81, P=0.016), RBPs of a wave on the ipsilateral occipitalia were decreased significantly (F=5.63, P=0.042).(2)The correlation between RBPs and MTTYTTP:the RBPs of δ,θ waves in MTT\TTP increased group on MCA ipsilateral MCA regions, ipsilateral occipitalia and the whole brain were significantly higher than that of MTT\TTP normal group, RBPs of a wave were decreased significantly(P<0.05). RBPs of a wave in MTT obviously elevated group were significantly lower than that in the MTT slightly elevated group on MCA ipsilateral MCA regions, ipsilateral occipitalia and the whole brain(F=14.793, P=.O04; F=10.63, P=0.01; F=5.927,P=0.038); RBPs of θ wave in TTP obviously elevated group were significantly higher than that in the TTP slightly elevated group on MCA ipsilateral MCA regions, ipsilateral occipitalia and the whole brain(F=10.825, P=0.009; F=7.343,P=0.024; F=1.262, P=0.025). Conclusion:1. There have significant differences in brain function between symptomatic and asymptomatic MCA stenosis, the RBPs of δ,θ waves of symptomatic group is significantly higher than that of asymptomatic group, the RBPs of a wave decreases significantly; there are some correlations between RBP indexes and NIHSS scores in symptomatic group; indicates that RBP indexes of qEEG parameters can be used as a valuable reference index of assessment in nerve function, condition changes, efficacy and prognosis in MCA stenosis or occlusion patients.2. The Vs of dvACA, dvPCA in asymptomatic group were significantly higher than that of symptomatic group, show that the asymptomatic MCA stenosis patients have a higher level of the collateral circulation opening up than the symptomatic group, indicates that TCD can be used to evaluate the hemodynamic changes and collateral circulations caused by MCA stenosis.3. Quantitative EEG and perfusion magnetic resonance imaging have consistency in the evaluation of cerebral ischemia after MCA stenosis, and the RBPs of8, α,β waves of qEEG parameters may respectively correlated with the index of CBF, MTT, TTP of PWI parameters.4.TCD combined with qEEG can better assess the neuronal function, collateral circulation and cerebral perfusion changes caused by cerebral ischemia after MCA stenosis, it can be used as an important means of condition assesment, clinical decision making, efficacy and prognosis in MCA stenosis or occlusion patients.